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+The Project Gutenberg EBook of Illusions, by James Sully
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: Illusions
+       A Psychological Study
+
+Author: James Sully
+
+Release Date: February 21, 2006 [EBook #17815]
+
+Language: English
+
+Character set encoding: ISO-8859-1
+
+*** START OF THIS PROJECT GUTENBERG EBOOK ILLUSIONS ***
+
+
+
+
+Produced by Thierry Alberto, Janet Blenkinship and the
+Online Distributed Proofreaders Europe at
+http://dp.rastko.net
+
+
+
+
+
+
+
+
+
+  ~ILLUSIONS~
+
+  _A PSYCHOLOGICAL STUDY_
+
+
+  BY
+  JAMES SULLY
+  AUTHOR OF "SENSATION AND INTUITION," "PESSIMISM," ETC.
+
+
+  THIRD EDITION
+
+
+
+
+  LONDON
+  KEGAN PAUL, TRENCH & CO., 1, PATERNOSTER SQUARE
+  1887
+
+  (_The rights of translation and of reproduction are reserved_)
+
+
+  ~THE INTERNATIONAL SCIENTIFIC SERIES.~
+
+  VOL. XXXIV.
+
+
+
+
+PREFACE.
+
+
+The present volume takes a wide survey of the field of error, embracing
+in its view not only the illusions of sense dealt with in treatises on
+physiological optics, etc., but also other errors familiarly known as
+illusions, and resembling the former in their structure and mode of
+origin. I have throughout endeavoured to keep to a strictly scientific
+treatment, that is to say, the description and classification of
+acknowledged errors, and the explanation of these by a reference to
+their psychical and physical conditions. At the same time, I was not
+able, at the close of my exposition, to avoid pointing out how the
+psychology leads on to the philosophy of the subject. Some of the
+chapters were first roughly sketched out in articles published in
+magazines and reviews; but these have been not only greatly enlarged,
+but, to a considerable extent, rewritten.
+                                                          J. S.
+
+  _Hampstead, April, 1881._
+
+
+
+
+  CONTENTS.
+
+
+  CHAPTER I.
+
+  THE STUDY OF ILLUSION.
+
+  Vulgar idea of Illusion, 1, 2; Psychological treatment of subject,
+  3, 4; definition of Illusion, 4-7; Philosophic extension of idea,
+  7, 8.
+
+
+  CHAPTER II.
+
+  THE CLASSIFICATION OF ILLUSIONS.
+
+  Popular and Scientific conceptions of Mind, 9, 10; Illusion and
+  Hallucination, 11-13; varieties of Immediate Knowledge, 13-16; four-fold
+  division of Illusions, 16-18.
+
+
+  CHAPTER III.
+
+  ILLUSIONS OF PERCEPTION: GENERAL.
+
+  _Psychology of Perception_:--The Psychological analysis of Perception,
+   19, 20; Sensation and its discrimination, etc., 20, 21; interpretation
+   of Sensation, 22, 23; construction of material object, 23, 24;
+   recognition of object, specific and individual, 24-27; Preperception
+   and Perception, 27-31; Physiological conditions of Perception, 31-33;
+   Visual and other Sense-perception, 33, 34.
+
+  _Illusions of Perception_:--Illusion of Perception defined, 35-38;
+   sources of Sense-illusion, 38-40: (a) confusion of
+   Sense-impression, 40-44; (b) misinterpretation of Sense-impression, 44;
+   Passive and Active misinterpretation, 44-46; Passive Illusions as
+   organically and extra-organically conditioned, 46-49.
+
+
+  CHAPTER IV.
+
+  ILLUSIONS OF PERCEPTION--_continued_.
+
+  A. _Passive Illusions (a) as determined by the Organism._
+  _Results of Limits of Sensibility_:--Relation of quantity of Sensation to
+  that of Stimulus, 50-52; coalescence of simultaneous Sensations,
+  52-55; after-effect of Stimulation, 55, 56; effects of prolonged
+  Stimulation, 56-58; Specific Energy of Nerves, 58, 59; localization
+  of Sensation, 59-62; Subjective Sensations, 62-64.
+
+  _Results of Variation of Sensibility_:--Rise and fall of Sensibility,
+  64-67; Paræsesthesia, 67, 68; _rationale_ of organically conditioned
+  Illusions, 68, 69.
+
+
+  CHAPTER V.
+
+  ILLUSIONS OF PERCEPTION--_continued_.
+
+  A. _Passive Illusions (b) as determined by the Environment._
+  _Exceptional Relation of Stimulus to Organ_:--Displacement of organ,
+  etc., 70-72.
+
+  _Exceptional Arrangement of Circumstances in the Environment_:--
+  Misinterpretation of the direction and movement of objects, 72-75;
+  misperception of Distance, 75, 76; Illusions of depth, relief, and
+  solidity in Art, 77-81; Illusions connected with the perception of
+  objects through transparent coloured media, 82-84; visual transformation
+  of concave into convex form, 84-86; false recognition of
+  objects, 86, 87; inattention to Sense-impression in Recognition,
+  87-91; suggestion taking the direction of familiar recurring experiences,
+  91, 92.
+
+
+  CHAPTER VI.
+
+  ILLUSIONS OF PERCEPTION--_continued_.
+
+  B. _Active Illusions._
+
+  Preperception and Illusion, 93-95.
+
+  _Voluntary Preperception_:--Choice of interpretation in the case of
+  visible movement, 95, 96; and in the case of flat projections of form,
+  96-98; capricious interpretation of obscure impressions, 99, 100.
+
+  _Involuntary Preperception_:--Effects of permanent Predisposition,
+  101, 102; effects of partial temporary Preadjustment, 102-105;
+  complete Pro-adjustment or Expectation, 106-109; subordination of
+  Sense-impression to Preperception, 109-111; transition from Illusion
+  to Hallucination, 111, 112; rudimentary Hallucinations, 112-114;
+  developed Hallucinations, 114-116; Hallucination in normal life,
+  116, 117; Hallucinations of insanity, 118-120; gradual development
+  of Sense-illusions, and continuity of normal and abnormal life; 120-123;
+  Sanity and Insanity distinguished, 123-126.
+
+
+  CHAPTER VII.
+
+  DREAMS.
+
+  Mystery of sleep, 127, 128; theories of Dreams, 128, 129; scientific
+  explanation of Dreams, 129, 130.
+
+  _Sleep and Dreaming_:--Condition of organism during sleep, 131, 132;
+  Are the nervous centres ever wholly inactive during sleep? 132-134;
+  nature of cerebral activity involved in Dreams, 134-136; psychical
+  conditions of Dreams, 136-138.
+
+  _The Dream as Illusion_:--External Sense-impressions as excitants of
+  Dream-images, 139-143; internal "subjective" stimuli in the sense-organs,
+  143-145; organic sensations, 145-147; how sensations are
+  exaggerated in Dream-interpretation, 147-151.
+
+  _The Dream as Hallucination_:--Results of direct central stimulation
+  151-153; indirect central stimulation and association, 153-155.
+
+  _The Form and Structure of Dreams_:--The incoherence of Dreams explained,
+  156-161; coherence and unity of Dream as effected (a) by
+  coalescence and transformation of images, 161-163; (b) by aground-tone
+  of feeling, 164-168; (c) by the play of associative dispositions,
+  168-172; (d) by the activities of selective attention stimulated by
+  the rational impulse to connect and to arrange, 172-176; examples
+  of Dreams, 176-179; limits of intelligence and rational activity in
+  Dreams, 180-182; Dreaming and mental disease, 182, 183; After-dreams
+  and Apparitions, 183-185.
+
+  NOTE.--The Hypnotic Condition, 185-188.
+
+
+  CHAPTER VIII.
+
+  ILLUSIONS OF INTROSPECTION.
+
+  Illusions of Introspection defined, 189-192; question of the possibility
+  of illusory Introspection, 192-194; incomplete grasp of internal
+  feelings as such, 194-196; misobservation of internal feelings: Passive
+  Illusions, 196-199; Active Illusions, 199-202; malobservation of
+  subjective states, 202-205; Illusory Introspection in psychology and
+  philosophy, 205-208; value of the Introspective method, 208-211.
+
+
+  CHAPTER IX.
+
+  OTHER QUASI-PRESENTATIVE ILLUSIONS: ERRORS OF INSIGHT.
+
+  Emotion and Perception, 212; Æsthetic Intuition, 213; Subjective
+  Impressions of beauty misinterpreted, 213-216; analogous Emotional
+  Intuitions, 216, 217; Insight, its nature, 217-220; Passive Illusions
+  of Insight, 220-222; Active Illusions of Insight: projection of
+  individual feelings, 222-224; the poetic transformation of nature,
+  224-226; special predispositions as falsifying Insight, 226-228;
+  value of faculty of Insight, 228-230.
+
+
+  CHAPTER X.
+
+  ILLUSIONS OF MEMORY.
+
+  Vulgar confidence in Memory, 231-233; definition of Memory, 233-235;
+  Psychology of Memory, 235-237; Physiology of Memory, 237, 238;
+  Memory as localization in the past, 238-241; Illusions of Memory
+  classified, 241-245.
+
+  (1) _Illusions of Time-Perspective_:--
+
+  (a) Definite Localization of events: constant errors in retrospective
+  estimate of time, 245-249; varying errors: estimate of duration
+  during a period, 249-251; variations in retrospective estimate of
+  duration, 251-256.
+
+  (b) Indefinite Localization: effect of vividness of mnemonic image
+  on the apparent distance of events, 256-258; isolated public events,
+  258, 259; active element in errors of Localization, 259-261.
+
+  (2) _Distortions of Memory_:--Transformation of past through
+  forgetfulness, 261-264; confusion of distinct recollections, 264-266;
+  Active Illusion: influence of present imaginative activity, 266-269;
+  exaggeration in recollections of remote experiences, 269, 270; action of
+  present feeling in transforming past, 270, 271.
+
+  (3) _Hallucinations of Memory_:--Their nature, 271-273; past dreams taken
+  for external experiences, 273-277; past waking imagination taken
+  for external reality, 277-280; recollection of prenatal ancestral
+  experience, 280, 281; filling up gaps in recollection, 281-283.
+  _Illusions connected with, Personal Identity_:--Illusions of Memory and
+  Sense of identity, 283, 284; idea of permanent self, how built up,
+  285-287; disturbances of sense of identity, 287-290; fallibility and
+  trustworthiness of Memory, 290-292.
+
+  NOTE.--Momentary Illusions of Self-consciousness, 293.
+
+
+  CHAPTER XI.
+
+  ILLUSIONS OF BELIEF.
+
+  Belief as Immediate or Intuitive, 294-296; simple and compound
+  Belief, 296.
+
+  A. _Simple Illusory Belief_:--
+
+      (1) Expectation: its nature, 297, 298; Is Expectation ever intuitive?
+        298; Expectation and Inference from the past, 299-301; Expectation
+        of new kinds of experience, 301, 302; Permanent Expectations
+        of remote events, 302; misrepresentation of future duration,
+        302-305; Imaginative transformation of future, 305-307.
+
+      (2) Quasi-Expectations: anticipation of extra-personal experiences,
+        307, 308; Retrospective Beliefs, 308-312.
+
+  B. _Compound Illusory Belief_:--
+
+      (1) Representations of permanent things: their structure, 312; our
+        representations of others as illusory, 312-315; our representation
+        of ourselves as illusory, 315; Illusion of self-esteem, 316-318;
+        genesis of illusory opinion of self, 318-322; Illusion in our
+        representations of classes of things, 322, 323; and in our views
+        of the world as a whole, 323, 324; tendency of belief towards
+        divergence, 325; and towards convergence, 326, 327.
+
+
+  CHAPTER XII.
+
+  RESULTS.
+
+  Range of Illusion, 328-330; nature and causes of Illusion in general,
+    331-334; Illusion identical with Fallacy, 334; Illusion as abnormal,
+    336, 337; question of common error, 337-339; evolutionist's conception
+    of error as maladaptation, 339-344; common intuitions
+    tested only by philosophy, 344; assumptions of science respecting
+    external reality, etc., 344-346; philosophic investigation of these
+    assumptions, 346-348; connection between scientific and philosophic
+    consideration of Illusion, 348-350; correction of Illusion and its
+    implications, 351, 352; Fundamental Intuitions and modern psychology,
+    352; psychology as positive science and as philosophy, 353-355;
+    points of resemblance between acknowledged Illusions and Fundamental
+    Intuitions, 355, 356; question of origin, and question of
+    validity, 356, 357; attitude of scientific mind towards philosophic
+    scepticism, 357-360; Persistent Intuitions must be taken as true,
+    360, 361.
+
+
+
+
+~ILLUSIONS.~
+
+
+
+
+CHAPTER I.
+
+THE STUDY OF ILLUSION.
+
+
+Common sense, knowing nothing of fine distinctions, is wont to draw a
+sharp line between the region of illusion and that of sane intelligence.
+To be the victim of an illusion is, in the popular judgment, to be
+excluded from the category of rational men. The term at once calls up
+images of stunted figures with ill-developed brains, half-witted
+creatures, hardly distinguishable from the admittedly insane. And this
+way of thinking of illusion and its subjects is strengthened by one of
+the characteristic sentiments of our age. The nineteenth century
+intelligence plumes itself on having got at the bottom of mediæval
+visions and church miracles, and it is wont to commiserate the feeble
+minds that are still subject to these self-deceptions.
+
+According to this view, illusion is something essentially abnormal and
+allied to insanity. And it would seem to follow that its nature and
+origin can be best studied by those whose speciality it is to observe
+the phenomena of abnormal life. Scientific procedure has in the main
+conformed to this distinction of common sense. The phenomena of illusion
+have ordinarily been investigated by alienists, that is to say,
+physicians who are brought face to face with their most striking forms
+in the mentally deranged.
+
+While there are very good reasons for this treatment of illusion as a
+branch of mental pathology, it is by no means certain that it can be a
+complete and exhaustive one. Notwithstanding the flattering supposition
+of common sense, that illusion is essentially an incident in abnormal
+life, the careful observer knows well enough that the case is far
+otherwise.
+
+There is, indeed, a view of our race diametrically opposed to the
+flattering opinion referred to above, namely, the humiliating judgment
+that all men habitually err, or that illusion is to be regarded as the
+natural condition of mortals. This idea has found expression, not only
+in the cynical exclamation of the misanthropist that most men are fools,
+but also in the cry of despair that sometimes breaks from the weary
+searcher after absolute truth, and from the poet when impressed with the
+unreality of his early ideals.
+
+Without adopting this very disparaging opinion of the intellectual
+condition of mankind, we must recognize the fact that most men are
+sometimes liable to illusion. Hardly anybody is always consistently
+sober and rational in his perceptions and beliefs. A momentary fatigue
+of the nerves, a little mental excitement, a relaxation of the effort of
+attention by which we continually take our bearings with respect to the
+real world about us, will produce just the same kind of confusion of
+reality and phantasm, which we observe in the insane. To give but an
+example: the play of fancy which leads to a detection of animal and
+other forms in clouds, is known to be an occupation of the insane, and
+is rightly made use of by Shakespeare as a mark of incipient mental
+aberration in Hamlet; and yet this very same occupation is quite natural
+to children, and to imaginative adults when they choose to throw the
+reins on the neck of their phantasy. Our luminous circle of rational
+perception is surrounded by a misty penumbra of illusion. Common sense
+itself may be said to admit this, since the greatest stickler for the
+enlightenment of our age will be found in practice to accuse most of his
+acquaintance at some time or another of falling into illusion.
+
+If illusion thus has its roots in ordinary mental life, the study of it
+would seem to belong to the physiology as much as to the pathology of
+mind. We may even go further, and say that in the analysis and
+explanation of illusion the psychologist may be expected to do more than
+the physician. If, on the one hand, the latter has the great privilege
+of observing the phenomena in their highest intensity, on the other
+hand, the former has the advantage of being familiar with the normal
+intellectual process which all illusion simulates or caricatures. To
+this it must be added that the physician is naturally disposed to look
+at illusion mainly, if not exclusively, on its practical side, that is,
+as a concomitant and symptom of cerebral disease, which it is needful to
+be able to recognize. The psychologist has a different interest in the
+subject, being specially concerned to understand the mental antecedents
+of illusion and its relation to accurate perception and belief. It is
+pretty evident, indeed, that the phenomena of illusion form a region
+common to the psychologist and the mental pathologist, and that the
+complete elucidation of the subject will need the co-operation of the
+two classes of investigator.
+
+In the present volume an attempt will be made to work out the
+psychological side of the subject; that is to say, illusions will be
+viewed in their relation to the process of just and accurate perception.
+In the carrying out of this plan our principal attention will be given
+to the manifestations of the illusory impulse in normal life. At the
+same time, though no special acquaintance with the pathology of the
+subject will be laid claim to, frequent references will be made to the
+illusions of the insane. Indeed, it will be found that the two groups of
+phenomena--the illusions of the normal and of the abnormal
+condition--are so similar, and pass into one another by such insensible
+gradations, that it is impossible to discuss the one apart from the
+other. The view of illusion which will be adopted in this work is that
+it constitutes a kind of border-land between perfectly sane and vigorous
+mental life and dementia.
+
+And here at once there forces itself on our attention the question, What
+exactly is to be understood by the term "illusion"? In scientific works
+treating of the pathology of the subject, the word is confined to what
+are specially known as illusions of the senses, that is to say, to false
+or illusory perceptions. And there is very good reason for this
+limitation, since such illusions of the senses are the most palpable
+and striking symptoms of mental disease. In addition to this, it must be
+allowed that, to the ordinary reader, the term first of all calls up
+this same idea of a deception of the senses.
+
+At the same time, popular usage has long since extended the term so as
+to include under it errors which do not counterfeit actual perceptions.
+We commonly speak of a man being under an illusion respecting himself
+when he has a ridiculously exaggerated view of his own importance, and
+in a similar way of a person being in a state of illusion with respect
+to the past when, through frailty of memory, he pictures it quite
+otherwise than it is certainly known to have been.
+
+It will be found, I think, that there is a very good reason for this
+popular extension of the term. The errors just alluded to have this in
+common with illusions of sense, that they simulate the form of immediate
+or self-evident cognition. An idea held respecting ourselves or
+respecting our past history does not depend on any other piece of
+knowledge; in other words, is not adopted as the result of a process of
+reasoning. What I believe with reference to my past history, so far as I
+can myself recall it, I believe instantaneously and immediately, without
+the intervention of any premise or reason. Similarly, our notions of
+ourselves are, for the most part, obtained apart from any process of
+inference. The view which a man takes of his own character or claims on
+society he is popularly supposed to receive intuitively by a mere act of
+internal observation. Such beliefs may not, indeed, have all the
+overpowering force which belongs to illusory perceptions, for the
+intuition of something by the senses is commonly looked on as the most
+immediate and irresistible kind of knowledge. Still, they must be said
+to come very near illusions of sense in the degree of their self-evident
+certainty.
+
+Taking this view of illusion, we may provisionally define it as any
+species of error which counterfeits the form of immediate, self-evident,
+or intuitive knowledge, whether as sense-perception or otherwise.
+Whenever a thing is believed on its own evidence and not as a conclusion
+from something else, and the thing then believed is demonstrably wrong,
+there is an illusion. The term would thus appear to cover all varieties
+of error which are not recognized as fallacies or false inferences. If
+for the present we roughly divide all our knowledge into the two regions
+of primary or intuitive, and secondary or inferential knowledge, we see
+that illusion is false or spurious knowledge of the first kind, fallacy
+false or spurious knowledge of the second kind. At the same time, it is
+to be remembered that this division is only a very rough one. As will
+appear in the course of our investigation, the same error may be called
+either a fallacy or an illusion, according as we are thinking of its
+original mode of production or of the form which it finally assumes; and
+a thorough-going psychological analysis of error may discover that these
+two classes are at bottom very similar.
+
+As we proceed, we shall, I think, find an ample justification for our
+definition. We shall see that such illusions as those respecting
+ourselves or the past arise by very much the same mental processes as
+those which are discoverable in the production of illusory perceptions;
+and thus a complete psychology of the one class will, at the same time,
+contain the explanation of the other classes.
+
+The reader is doubtless aware that philosophers have still further
+extended the idea of illusion by seeking to bring under it beliefs which
+the common sense of mankind has always adopted and never begun to
+suspect. Thus, according to the idealist, the popular notion (the
+existence of which Berkeley, however, denied) of an external world,
+existing in itself and in no wise dependent on our perceptions of it,
+resolves itself into a grand illusion of sense.
+
+At the close of our study of illusions we shall return to this point. We
+shall there inquire into the connection between those illusions which
+are popularly recognized as such, and those which first come into view
+or appear to do so (for we must not yet assume that there are such)
+after a certain kind of philosophic reflection. And some attempt will be
+made to determine roughly how far the process of dissolving these
+substantial beliefs of mankind into airy phantasms may venture to go.
+
+For the present, however, these so-called illusions in philosophy will
+be ignored. It is plain that illusion exists only in antithesis to real
+knowledge. This last must be assumed as something above all question.
+And a rough and provisional, though for our purpose sufficiently
+accurate, demarcation of the regions of the real and the illusory seems
+to coincide with the line which common sense draws between what all
+normal men agree in holding and what the individual holds, whether
+temporarily or permanently, in contradiction to this. For our present
+purpose the real is that which is true for all. Thus, though physical
+science may tell us that there is nothing corresponding to our
+sensations of colour in the world of matter and motion which it
+conceives as surrounding us; yet, inasmuch as to all men endowed with
+the normal colour-sense the same material objects appear to have the
+same colour, we may speak of any such perception as practically true,
+marking it off from those plainly illusory perceptions which are due to
+some subjective cause, as, for example, fatigue of the retina.
+
+To sum up: in treating of illusions we shall assume, what science as
+distinguished from philosophy is bound to assume, namely, that human
+experience is consistent; that men's perceptions and beliefs fall into a
+consensus. From this point of view illusion is seen to arise through
+some exceptional feature in the situation or condition of the
+individual, which, for the time, breaks the chain of intellectual
+solidarity which under ordinary circumstances binds the single member to
+the collective body. Whether the common experience which men thus obtain
+is rightly interpreted is a question which does not concern us here. For
+our present purpose, which is the determination and explanation of
+illusion as popularly understood, it is sufficient that there is this
+general consensus of belief, and this may provisionally be regarded as
+at least practically true.
+
+
+
+
+CHAPTER II.
+
+THE CLASSIFICATION OF ILLUSIONS.
+
+
+If illusion is the simulation of immediate knowledge, the most obvious
+mode of classifying illusions would appear to be according to the
+variety of the knowledge which they simulate.
+
+Now, the popular psychology that floats about in the ordinary forms of
+language has long since distinguished certain kinds of unreasoned or
+uninferred knowledge. Of these the two best known are perception and
+memory. When I see an object before me, or when I recall an event in my
+past experience, I am supposed to grasp a piece of knowledge directly,
+to know something immediately, and not through the medium of something
+else. Yet I know differently in the two cases. In the first I know by
+what is called a presentative process, namely, that of sense-perception;
+in the second I know by a representative process, namely, that of
+reproduction, or on the evidence of memory. In the one case the object
+of cognition is present to my perceptive faculties; in the other it is
+recalled by the power of memory.
+
+Scientific psychology tends, no doubt, to break down some of these
+popular distinctions. Just as the zoologist sometimes groups together
+varieties of animals which the unscientific eye would never think of
+connecting, so the psychologist may analyze mental operations which
+appear widely dissimilar to the popular mind, and reduce them to one
+fundamental process. Thus recent psychology draws no sharp distinction
+between perception and recollection. It finds in both very much the same
+elements, though combined in a different way. Strictly speaking, indeed,
+perception must be defined as a presentative-representative operation.
+To the psychologist it comes to very much the same thing whether, for
+example, on a visit to Switzerland, our minds are occupied in
+_perceiving_ the distance of a mountain or in _remembering_ some
+pleasant excursion which we made to it on a former visit. In both cases
+there is a reinstatement of the past, a reproduction of earlier
+experience, a process of adding to a present impression a product of
+imagination--taking this word in its widest sense. In both cases the
+same laws of reproduction or association are illustrated.
+
+Just as a deep and exhaustive analysis of the intellectual operations
+thus tends to identify their various forms as they are distinguished by
+the popular mind, so a thorough investigation of the flaws in these
+operations, that is to say, the counterfeits of knowledge, will probably
+lead to an identification of the essential mental process which
+underlies them. It is apparent, for example, that, whether a man
+_projects_ some figment of his imagination into the external world,
+giving it, present material reality, or whether (if I may be allowed the
+term) he _retrojects_ it into the dim region of the past, and takes it
+for a reality that has been he is committing substantially the same
+blunder. The source of the illusion in both cases is one and the same.
+
+It might seem to follow from this that a scientific discussion of the
+subject would overlook the obvious distinction between illusions of
+perception and those of memory; that it would attend simply to
+differences in the mode of origination of the illusion, whatever its
+external form. Our next step, then, would appear to be to determine
+these differences in the mode of production.
+
+That there are differences in the origin and source of illusion is a
+fact which has been fully recognized by those writers who have made a
+special study of sense-illusions. By these the term illusion is commonly
+employed in a narrow, technical sense, and opposed to hallucination. An
+illusion, it is said, must always have its starting-point in some actual
+impression, whereas a hallucination has no such basis. Thus it is an
+illusion when a man, under the action of terror, takes a stump of a
+tree, whitened by the moon's rays, for a ghost. It is a hallucination
+when an imaginative person so vividly pictures to himself the form of
+some absent friend that, for the moment, he fancies himself actually
+beholding him. Illusion is thus a partial displacement of external fact
+by a fiction of the imagination, while hallucination is a total
+displacement.
+
+This distinction, which has been adopted by the majority of recent
+alienists[1], is a valuable one, and must not be lost sight of here. It
+would seem, from a psychological point of view, to be an important
+circumstance in the genesis of a false perception whether the
+intellectual process sets out from within or from without. And it will
+be found, moreover, that this distinction may be applied to all the
+varieties of error which I propose to consider. Thus, for example, it
+will be seen further on that a false recollection may set out either
+from the idea of some actual past occurrence or from a present product
+of the imagination.
+
+It is to be observed, however, that the line of separation between
+illusion and hallucination, as thus defined, is a very narrow one. In by
+far the largest number of hallucinations it is impossible to prove that
+there is no modicum of external agency co-operating in the production of
+the effect. It is presumable, indeed, that many, if not all,
+hallucinations have such a basis of fact. Thus, the madman who projects
+his internal thoughts outwards in the shape of external voices may, for
+aught we know, be prompted to do so in part by faint impressions coming
+from the ear, the result of those slight stimulations to which the organ
+is always exposed, even in profound silence, and which in his case
+assume an exaggerated intensity. And even if it is clearly made out that
+there are hallucinations in the strict sense, that is to say, false
+perceptions which are wholly due to internal causes, it must be conceded
+that illusion shades off into hallucination by steps which it is
+impossible for science to mark. In many cases it must be left an open
+question whether the error is to be classed as an illusion or as a
+hallucination.[2]
+
+For these reasons, I think it best not to make the distinction between
+illusion and hallucination the leading principle of my classification.
+However important psychologically, it does not lend itself to this
+purpose. The distinction must be kept in view and illustrated as far as
+possible. Accordingly, while in general following popular usage and
+employing the term illusion as the generic name, I shall, when
+convenient, recognize the narrow and technical sense of the term as
+answering to a species co-ordinate with hallucination.
+
+Departing, then, from what might seem the ideally best order of
+exposition, I propose, after all, to set out with the simple popular
+scheme of faculties already referred to. Even if they are,
+psychologically considered, identical operations, perception and memory
+are in general sufficiently marked off by a speciality in the form of
+the operation. Thus, while memory is the reproduction of something with
+a special reference of consciousness to its past existence, perception
+is the reproduction of something with a special reference to its present
+existence as a part of the presented object. In other words, though
+largely _representative_ when viewed as to its origin, perception is
+_presentative_ in relation to the object which is supposed to be
+immediately present to the mind at the moment.[3] Hence the convenience
+of recognizing the popular classification, and of making it our
+starting-point in the present case.
+
+All knowledge which has any appearance of being directly reached,
+immediate, or self-evident, that is to say, of not being inferred from
+other knowledge, may be divided into four principal varieties: Internal
+Perception or Introspection of the mind's own feelings;
+External Perception; Memory; and Belief, in so far as it simulates the
+form of direct knowledge. The first is illustrated in a man's
+consciousness of a present feeling of pain or pleasure. The second and
+the third kinds have already been spoken of, and are too familiar to
+require illustration. It is only needful to remark here that, under
+perception, or rather in close conjunction with it, I purpose dealing
+with the knowledge of other's feelings, in so far as this assumes the
+aspect of immediate knowledge. The term belief is here used to include
+expectations and any other kinds of conviction that do not fall under
+one of the other heads. An instance of a seemingly immediate belief
+would be a prophetic prevision of a coming disaster, or a man's
+unreasoned persuasion as to his own powers of performing a difficult
+task.
+
+It is, indeed, said by many thinkers that there are no legitimate
+immediate beliefs; that all our expectations and other convictions about
+things, in so far as they are sound, must repose on other genuinely
+immediate knowledge, more particularly sense-perception and memory.
+This difficult question need not be discussed here. It is allowed by all
+that there is a multitude of beliefs which we hold tenaciously and on
+which we are ready to act, which, to the mature mind, wear the
+appearance of intuitive truths, owing their cogency to nothing beyond
+themselves. A man's belief in his own merits, however it may have been
+first obtained, is as immediately assured to him as his recognition of a
+real object in the act of sense-perception. It may be added that many of
+our every-day working beliefs about the world in which we live, though
+presumably derived from memory and perception, tend to lose all traces
+of their origin, and to simulate the aspect of intuitions. Thus the
+proposition that logicians are in the habit of pressing on our
+attention, that "Men are mortal," seems, on the face of it, to common
+sense to be something very like a self-evident truth, not depending on
+any particular facts of experience.
+
+In calling these four forms of cognition immediate, I must not, however,
+be supposed to be placing them on the same logical level. It is plain,
+indeed, to a reflective mind that, though each may be called immediate
+in this superficial sense, there are perceptible differences in the
+degree of their immediacy. Thus it is manifest, after a moment's
+reflection, that expectation, so far as it is just, is not primarily
+immediate in the sense in which purely presentative knowledge is so,
+since it can be shown to follow from something else. So a general
+proposition, though through familiarity and innumerable illustrations it
+has acquired a self-evident character, is seen with a very little
+inspection to be less fundamentally and essentially so than the
+proposition, "I am now feeling pain;" and it will be found that even
+with respect to memory, when the remembered event is at all remote, the
+process of cognition approximates to a mediate operation, namely, one of
+inference. What the relative values of these different kinds of
+immediate knowledge are is a point which will have to be touched on at
+the end of our study. Here it must suffice to warn the reader against
+the supposition that this value is assumed to be identical.
+
+It might seem at a first glance to follow from this four-fold scheme of
+immediate or quasi-immediate knowledge that there are four varieties of
+illusion. And this is true in the sense that these four heads cover all
+the main varieties of illusion. If there are only four varieties of
+knowledge which can lay any claim to be considered immediate, it must be
+that every illusion will simulate the form of one of these varieties,
+and so be referable to the corresponding division.
+
+But though there are conceivably these four species of illusion, it does
+not follow that there are any actual instances of each class
+forthcoming. This we cannot determine till we have investigated the
+nature and origin of illusory error. For example, it might be found that
+introspection, or the immediate inspection of our own feelings or mental
+states, does not supply the conditions necessary to the production of
+such error. And, indeed, it is probable that most persons, antecedently
+to inquiry, would be disposed to say that to fall into error in the
+observation of what is actually going on in our own minds is
+impossible.
+
+With the exception of this first division, however, this scheme may
+easily be seen to answer to actual phenomena. That there are illusions
+of perception is obvious, since it is to the errors of sense that the
+term illusion has most frequently been confined. It is hardly less
+evident that there are illusions of memory. The peculiar difficulty of
+distinguishing between a past real event and a mere phantom of the
+imagination, illustrated in the exclamation, "I either saw it or dreamt
+it," sufficiently shows that memory is liable to be imposed on. Finally,
+it is agreed on by all that the beliefs we are wont to regard as
+self-evident are sometimes erroneous. When, for example, an imaginative
+woman says she knows, by mere intuition, that something interesting is
+going to happen, say the arrival of a favourite friend, she is plainly
+running the risk of being self-deluded. So, too, a man's estimate of
+himself, however valid for him, may turn out to be flagrantly false.
+
+In the following discussion of the subject I shall depart from the above
+order in so far as to set out with illusions of sense-perception. These
+are well ascertained, forming, indeed, the best-marked variety. And the
+explanation of these has been carried much further than that of the
+others. Hence, according to the rule to proceed from the known to the
+unknown, there will be an obvious convenience in examining these first
+of all. After having done this, we shall be in a position to inquire
+whether there is anything analogous in the region of introspection or
+internal perception. Our study of the errors of sense-perception will,
+moreover, prove the best preparation for an inquiry into the nature and
+mode of production of the remaining two varieties.[4]
+
+I would add that, in close connection with the first division, illusions
+of perception, I shall treat the subtle and complicated phenomena of
+dreams. Although containing elements which ought, according to
+strictness, to be brought under one of the other heads, they are, as
+their common appellation, "visions," shows, largely simulations of
+external, and more especially visual, perception.
+
+Dreams are no doubt sharply marked off from illusions of
+sense-perception by a number of special circumstances. Indeed, it may be
+thought that they cannot be adequately treated in a work that aims
+primarily at investigating the illusions of normal life, and should
+rather be left to those who make the pathological side of the subject
+their special study. Yet it may, perhaps, be said that in a wide sense
+dreams are a feature of normal life. And, however this be, they have
+quite enough in common with other illusions of perception to justify us
+in dealing with them in close connection with these.
+
+
+
+
+CHAPTER III.
+
+ILLUSIONS OF PERCEPTION: GENERAL.
+
+
+The errors with which we shall be concerned in this chapter are those
+which are commonly denoted by the term illusion, that is to say, those
+of sense. They are sometimes called deceptions of the senses; but this
+is a somewhat loose expression, suggesting that we can be deceived as to
+sensation itself, though, as we shall see later on, this is only true in
+a very restricted meaning of the phrase. To speak correctly,
+sense-illusions must be said to arise by a simulation of the form of
+just and accurate perceptions. Accordingly, we shall most frequently
+speak of them as illusions of perception.
+
+In order to investigate the nature of any kind of error, it is needful
+to understand the kind of knowledge it imitates, and so we must begin
+our inquiry into the nature of illusions of sense by a brief account of
+the psychology of perception; and, in doing this, we shall proceed best
+by regarding this operation in its most complete form, namely, that of
+visual perception.
+
+I may observe that in this analysis of perception I shall endeavour to
+keep to known facts, namely, the psychical phenomena or events which
+can be seen by the methods of scientific psychology to enter into the
+mental content called the percept. I do not now inquire whether such an
+analysis can help us to understand all that is meant by perception. This
+point will have to be touched later on. Here it is enough to say that,
+whatever our philosophy of perception may be, we must accept the
+psychological fact that the concrete mental state in the act of
+perception is built up out of elements, the history of which can be
+traced by the methods of mental science.
+
+
+_Psychology of Perception._
+
+Confining ourselves for the present to the mental, as distinguished from
+the physical, side of the operation, we soon find that perception is not
+so simple a matter as it might at first seem to be. When a man on a hot
+day looks at a running stream and "sees" the delicious coolness, it is
+not difficult to show that he is really performing an act of mental
+synthesis, or imaginative construction. To the sense-impression[5] which
+his eye now gives him, he adds something which past experience has
+bequeathed to his mind. In perception, the material of sensation is
+acted on by the mind, which embodies in its present attitude all the
+results of its past growth. Let us look at this process of synthesis a
+little more closely.
+
+When a sensation arises in the mind, it may, under certain
+circumstances, go unattended to. In that case there is no perception.
+The sensation floats in the dim outer regions of consciousness as a
+vague feeling, the real nature and history of which are unknown. This
+remark applies not only to the undefined bodily sensations that are
+always oscillating about the threshold of obscure consciousness, but to
+the higher sensations connected with the special organs of perception.
+The student in optics soon makes the startling discovery that his field
+of vision has all through his life been haunted with weird shapes which
+have never troubled the serenity of his mind just because they have
+never been distinctly attended to.
+
+The immediate result of this process of directing the keen glance of
+attention to a sensation is to give it greater force and distinctness.
+By attending to it we discriminate it from other feelings present and
+past, and classify it with like sensations previously received. Thus, if
+I receive a visual impression of the colour orange, the first
+consequence of attending to it is to mark it off from other
+colour-impressions, including those of red and yellow. And in
+recognizing the peculiar quality of the impression by applying to it the
+term orange, I obviously connect it with other similar sensations called
+by the same name. If a sensation is perfectly new, there cannot, of
+course, be this process of classifying, and in this case the closely
+related operation of discriminating it from other sensations is less
+exactly performed. But it is hardly necessary to remark that, in the
+mind of the adult, under ordinary circumstances, no perfectly new
+sensation ever occurs.
+
+When the sensation, or complex sensation, is thus defined and
+recognized, there follows the process of interpretation, by which I mean
+the taking up of the impression as an element into the complex mental
+state known as a percept. Without going into the philosophical question
+of what this process of synthesis exactly means, I may observe that, by
+common consent, it takes place to a large extent by help of a
+reproduction of sensations of various kinds experienced in the past.
+That is to say, the details in this act of combination are drawn from
+the store of mental recollections to which the growing mind is ever
+adding. In other words, the percept arises through a fusion of an actual
+sensation with mental representations or "images" of sensation.[6] Every
+element of the object that we thus take up in the act of perception, or
+put into the percept, as its actual size, distance, and so on, will be
+found to make itself known to us through mental images or revivals of
+past experiences, such as those we have in handling the object, moving
+to and from it, etc. It follows that if this is an essential ingredient
+in the act of perception, the process closely resembles an act of
+inference; and, indeed, Helmholtz distinctly calls the perception of
+distance an unconscious inference or a mechanically performed act of
+judgment.
+
+I have hinted that these recovered sensations include the feelings we
+experience in connection with muscular activity, as in moving our limbs,
+resisting or lifting heavy bodies, and walking to a distant object.
+Modern psychology refers the eye's instantaneous recognition of the most
+important elements of an object (its essential or "primary" qualities)
+to a reinstatement of such simple experiences as these. It is, indeed,
+these reproductions which are supposed to constitute the substantial
+background of our percepts.
+
+Another thing worth noting with respect to this process of filling up a
+sense-impression is that it draws on past sensations of the eye itself.
+Thus, when I look at the figure of an acquaintance from behind, my
+reproductive visual imagination supplies a representation of the
+impressions I am wont to receive when the more interesting aspect of the
+object, the front view, is present to my visual sense.[7]
+
+We may distinguish between different steps in the full act of visual
+recognition. First of all comes the construction of a material object of
+a particular figure and size, and at a particular distance; that is to
+say, the recognition of a tangible thing having certain simple
+space-properties, and holding a certain relation to other objects, and
+more especially our own body, in space. This is the bare perception of
+an object, which always takes place even in the case of perfectly new
+objects, provided they are seen with any degree of distinctness. It is
+to be added that the reference of a sensation of light or colour to such
+an object involves the inclusion of a quality answering to the
+sensation, as brightness, or blue colour, in the thing thus intuited.
+
+This part of the process of filling in, which is the most instantaneous,
+automatic, and unconscious, may be supposed to answer to the most
+constant and therefore the most deeply organized connections of
+experience; for, speaking generally, we never have an impression of
+colour, except when there are circumstances present which are fitted to
+yield us those simple muscular and tactual experiences through which the
+ideas of a particular form, size, etc., are pretty certainly obtained.
+
+The second step in this process of presentative construction is the
+recognition of an object as one of a class of things, for example,
+oranges, having certain special qualities, as a particular taste. In
+this step the connections of experience are less deeply organized, and
+so we are able to some extent, by reflection, to recognize it as a kind
+of intellectual working up of the materials supplied us by the past. It
+is to be noted that this process of recognition involves a compound
+operation of classifying impressions as distinguished from that simple
+operation by which a single impression, such as a particular colour, is
+known. Thus the recognition of such an object as an orange takes place
+by a rapid classing of a multitude of passive sensations of colour,
+light, and shade, and those active or muscular sensations which are
+supposed to enter into the visual perception of form.
+
+A still less automatic step in the process of visual recognition is that
+of identifying individual objects, as Westminster Abbey, or a friend,
+John Smith. The amount of experience that is here reproduced may be very
+large, as in the case of recognizing a person with whom we have had a
+long and intimate acquaintance.
+
+If the recognition of an object as one of a class, for example, an
+orange, involves a compound process of classing impressions, that of an
+individual object involves a still more complicated process. The
+identification of a friend, simple as this operation may at first
+appear, really takes place by a rapid classing of all the salient
+characteristic features which serve as the visible marks of that
+particular person.
+
+It is to be noted that each kind of recognition, specific and
+individual, takes place by a consciousness of likeness amid unlikeness.
+It is obvious that a new individual object has characters not shared in
+by other objects previously inspected. Thus, we at once class a man with
+a dark-brown skin, wearing a particular garb, as a Hindoo, though he may
+differ in a host of particulars from the other Hindoos that we have
+observed. In thus instantly recognizing him as a Hindoo, we must, it is
+plain, attend to the points of similarity, and overlook for the instant
+the points of dissimilarity. In the case of individual identification,
+the same thing happens. Strictly speaking, no object ever appears
+exactly the same to us on two occasions. Apart from changes in the
+object itself, especially in the case of living beings, there are
+varying effects of illumination, of position in relation to the eye, of
+distance, and so on, which very distinctly affect the visual impression
+at different times. Yet the fact of our instantly recognizing a familiar
+object in spite of these fluctuations of appearance, proves that we are
+able to overlook a very considerable amount of diversity when a certain
+amount of likeness is present.
+
+It is further to be observed that in these last stages of perception we
+approach the boundary line between perception and inference. To
+recognize an object as one of a class is often a matter of conscious
+reflection and judgment, even when the class is constituted by obvious
+material qualities which the senses may be supposed to apprehend
+immediately. Still more clearly does perception pass into inference when
+the class is constituted by less obvious qualities, which require a
+careful and prolonged process of recollection, discrimination, and
+comparison, for their recognition. Thus, to recognize a man by certain
+marks of gesture and manner as a military man or a Frenchman, though
+popularly called a perception, is much more of an unfolded process of
+conscious inference. And what applies to specific recognition applies
+still more forcibly to individual recognition, which is often a matter
+of very delicate conscious comparison and judgment. To say where the
+line should be drawn here between perception and observation on the one
+hand, and inference on the other, is clearly impossible. Our whole study
+of the illusions of perception will serve to show that the one shades
+off into the other too gradually to allow of our drawing a hard and fast
+line between them.
+
+Finally, it is to be noted that these last stages of perception bring us
+near the boundary line which separates objective experience as common
+and universal, and subjective or variable experience as confined to one
+or to a few. In the bringing of the object under a certain class of
+objects there is clearly room for greater variety of individual
+perception. For example, the ability to recognize a man as a Frenchman
+turns on a special kind of previous experience. And this transition from
+the common or universal to the individual experience is seen yet more
+plainly in the case of individual recognition. To identify an object,
+say a particular person, commonly presupposes some previous experience
+or knowledge of this object, and the existence in the past of some
+special relation of the recognizer to the recognized, if only that of an
+observer. In fact, it is evident that in this mode of recognition we
+have the transition from common perception to individual
+recollection.[8]
+
+While we may thus distinguish different steps in the process of visual
+recognition, we may make a further distinction, marking off a passive
+and an active stage in the process. The one may be called the stage of
+preperception, the other that of perception proper.[9] In the first the
+mind holds itself in a passive attitude, except in so far as the
+energies of external attention are involved. The impression here awakens
+the mental images which answer to past experiences according to the
+well-known laws of association. The interpretative image which is to
+transform the impression into a percept is now being formed by a mere
+process of suggestion.
+
+When the image is thus formed, the mind may be said to enter upon a more
+active stage, in which it now views the impression through the image, or
+applies this as a kind of mould or framework to the impression. This
+appears to involve an intensification of the mental image, transforming
+it from a representative to a presentative mental state, making it
+approximate somewhat to the full intensity of the sensation. In many of
+our instantaneous perceptions these two stages are indistinguishable to
+consciousness. Thus, in most cases, the recognition of size, distance,
+etc., takes place so rapidly that it is impossible to detect the two
+phases here separated. But in the classification of an object, or the
+identification of an individual thing, there is often an appreciable
+interval between the first reception of the impression and the final
+stage of complete recognition. And here it is easy to distinguish the
+two stages of preperception and perception. The interpretative image is
+slowly built up by the operation of suggestion, at the close of which
+the impression is suddenly illumined as by a flash of light, and takes a
+definite, precise shape.
+
+Now, it is to be noted that the process of preperception will be greatly
+aided by any circumstance that facilitates the construction of the
+particular interpretative image required. Thus, the more frequently a
+similar process of perception has been performed in the past, the more
+ready will the mind be to fall into the particular way of interpreting
+the impression. As G.H. Lewes well remarks, "The artist sees details
+where to other eyes there is a vague or confused mass; the naturalist
+sees an animal where the ordinary eye only sees a form." This is but one
+illustration of the seemingly universal mental law, that what is
+repeatedly done will be done more and more easily.
+
+The process of preperception may be shortened, not only by means of a
+_permanent_ disposition to frame the required interpretative scheme, the
+residuum of past like processes, but also by means of any _temporary_
+disposition pointing in the same direction. If, for example, the mind of
+a naturalist has just been occupied about a certain class of bird, that
+is to say, if he has been dwelling on the _mental image_ of this bird,
+he will recognize one at a distance more quickly than he would otherwise
+have done. Such a simple mental operation as the recognition of one of
+the less common flowers, say a particular orchid, will vary in duration
+according as we have or have not been recently forming an image of this
+flower. The obvious explanation of this is that the mental image of an
+object bears a very close resemblance to the corresponding percept,
+differing from it, indeed, in degree only, that is to say, through the
+fact that it involves no actual sensation. Here again we see illustrated
+a general psychological law, namely, that what the mind has recently
+done, it tends (within certain limits) to go on doing.
+
+It is to be noticed, further, that the perception of a single object or
+event is rarely an isolated act of the mind. We recognize and understand
+the things that surround us through their relations one to another.
+Sometimes the adjacent circumstances and events suggest a definite
+expectation of the new impression. Thus, for example, the sound of a gun
+heard during a walk in the country is instantly interpreted by help of
+suggestions due to the previous appearance of the sportsman, and the act
+of raising the gun to his shoulder. It may be added that the verbal
+suggestions of others act very much like the suggestions of external
+circumstances. If I am told that a gun is going to be fired, my mind is
+prepared for it just as though I saw the sportsman.[10]
+
+More frequently the effect of such surrounding circumstances is to give
+an air of familiarity to the new impression, to shorten the interval in
+which the required interpretative image is forthcoming. Thus, when
+travelling in Italy, the visual impression answering to a ruined temple
+or a bareheaded friar is construed much more rapidly than it would be
+elsewhere, because of the attitude of mind due to the surrounding
+circumstances. In all such cases the process of preperception connected
+with a given impression is effected more or less completely by the
+suggestions of other and related impressions.
+
+It follows from all that has been just said that our minds are never in
+exactly the same state of readiness with respect to a particular process
+of perceptional interpretation. Sometimes the meaning of an impression
+flashes on us at once, and the stage of preperception becomes
+evanescent. At other times the same impression will fail for an
+appreciable interval to divulge its meaning. These differences are, no
+doubt, due in part to variations in the state of attention at the
+moment; but they depend as well on fluctuations in the degree of the
+mind's readiness to look at the impression in the required way.
+
+In order to complete this slight analysis of perception, we must look
+for a moment at its physical side, that is to say, at the nervous
+actions which are known or supposed with some degree of probability to
+accompany it.
+
+The production of the sensation is known to depend on a certain external
+process, namely, the action of some stimulus, as light, on the
+sense-organ, which stimulus has its point of departure in the object,
+such as it is conceived by physical science. The sensation arises when
+the nervous process is transmitted through the nerves to the conscious
+centre, often spoken of as the sensorium, the exact seat of which is
+still a matter of some debate.
+
+The intensification of the sensation by the reaction of attention is
+supposed to depend on some reinforcement of the nervous excitation in
+the sensory centre proceeding from the motor regions, which are
+hypothetically regarded as the centre of attention.[11] The
+classification of the impression, again, is pretty certainly correlated
+with the physical fact that the central excitation calls into activity
+elements which have already been excited in the same way.
+
+The nervous counterpart of the final stage of perception, the synthesis
+of the sensation and the mental representation, is not clearly
+ascertained. A sensation clearly resembles a mental image in quality. It
+is most obviously marked off from the image by its greater vividness or
+intensity. Agreeably to this view, it is now held by a number of eminent
+physiologists and psychologists that the nervous process underlying a
+sensation occupies the same central region as that which underlies the
+corresponding image. According to this theory, the two processes differ
+in their degree of energy only, this difference being connected with the
+fact that the former involves, while the latter does not involve, the
+peripheral region of the nervous system. Accepting this view as on the
+whole well founded, I shall speak of an ideational, or rather an
+imaginational; and a sensational nervous process, and not of an
+ideational and a sensational centre.[12]
+
+The special force that belongs to the representative element in a
+percept, as compared with that of a pure "perceptional" image,[13] is
+probably connected with the fact that, in the case of actual perception,
+the nervous process underlying the act of imaginative construction is
+organically united to the initial sensational process, of which indeed
+it may be regarded as a continuation.
+
+For the physical counterpart of the two stages in the interpretative
+part of perception, distinguished as the passive stage of preperception,
+and the active stage of perception proper, we may, in the absence of
+certain knowledge, fall back on the hypothesis put forward by Dr. J.
+Hughlings Jackson, in the articles in _Brain_ already referred to,
+namely, that the former answers to an action of the right hemisphere of
+the brain, the latter to a subsequent action of the left hemisphere. The
+expediting of the process of preperception in those cases where it has
+frequently been performed before, is clearly an illustration of the
+organic law that every function is improved by exercise. And the
+temporary disposition to perform the process due to recent imaginative
+activity, is explained at once on the physical side by the supposition
+that an actual perception and a perceptional image involve the activity
+of the same nervous tracts. For, assuming this to be the case, it
+follows, from a well-known organic law, that a recent excitation would
+leave a temporary disposition in these particular structures to resume
+that particular mode of activity.
+
+What has here been said about visual perception will apply, _mutatis
+mutandis_, to other kinds. Although the eye is the organ of perception
+_par excellence_, our other senses are also avenues by which we intuit
+and recognize objects. Thus touch, especially when it is finely
+developed as it is in the blind, gives an immediate knowledge of
+objects--a more immediate knowledge, indeed, of their fundamental
+properties than sight. What makes the eye so vastly superior to the
+organ of touch as an instrument of perception, is first of all the range
+of its action, taking in simultaneously a large number of impressions
+from objects at a distance as well as near; and secondly, though this
+may seem paradoxical, the fact that it gives us so much indirectly, that
+is, by way of association and suggestion. This is the interesting side
+of visual perception, that, owing to the vast complex of distinguishable
+sensations of light and colour of various qualities and intensities,
+together with the muscular sensations attending the varying positions of
+the organ, the eye is able to recognize at any instant a whole external
+world with its fundamental properties and relations. The ear comes next
+to the eye in this respect, but only after a long interval, since its
+sensations (even in the case of musical combinations) do not
+simultaneously order themselves in an indefinitely large group of
+distinguishable elements, and since even the comparatively few
+sensations which it is capable of simultaneously receiving,
+being altogether passive--that is to say, having no muscular
+accompaniments--impart but little and vague information respecting the
+external order. It is plain, then, that in the study of illusion, where
+the indirectly known elements are the thing to be considered, the eye,
+and after this the ear, will mostly engage our attention.[14]
+
+So much it seemed needful to say about the mechanism of perception, in
+order to understand the slight disturbances of this mechanism that
+manifest themselves in sense-illusion. It may be added that our study of
+these illusions will help still further to elucidate the exact nature of
+perception. Normal mental life, as a whole, at once illustrates, and is
+illustrated by, abnormal. And while we need a rough provisional theory
+of accurate perception in order to explain illusory perception at all,
+the investigation of this latter cannot fail to verify and even render
+more complete the theory which it thus temporarily adopts.
+
+
+_Illusions of Perception._
+
+With this brief psychological analysis of perception to help us, let us
+now pass to the consideration of the errors incident to the process,
+with a view to classify them according to their psychological nature and
+origin.
+
+And here there naturally arises the question, How shall we define an
+illusion of perception? When trying to fix the definition of illusion in
+general, I practically disposed of this question. Nevertheless, as the
+point appears to me to be of some importance, I shall reproduce and
+expand one or two of the considerations then brought forward.
+
+It is said by certain, philosophers that perception, as a whole, is an
+illusion, inasmuch as it involves the fiction of a real thing
+independent of mind, yet somehow present to it in the act of
+sense-perception. But this is a question for philosophy, not for
+science. Science, including psychology, assumes that in perception there
+is something real, without inquiring what it may consist of, or what its
+meaning may be. And though in the foregoing analysis of perception,
+viewed as a complex mental phenomenon or psychical process, I have
+argued that a percept gets its concrete filling up out of elements of
+conscious experience or sensations, I have been careful not to contend
+that the particular elements of feeling thus represented are the
+_object_ of perception or the thing perceived. It may be that what we
+mean by a single object with its assemblage of qualities is much more
+than any number of such sensations; and it must be confessed that, on
+the face of it, it seems to be much more. And however this be, the
+question, What is meant by object; and is the common persuasion of the
+existence of such an entity in the act of perception accurate or
+illusory? must be handed over to philosophy.
+
+While in the following examination of sense-illusions we put out of
+sight what certain philosophers say about the illusoriness of perception
+as a whole, we shall also do well to leave out of account what physical
+science is sometimes supposed to tell us respecting a constant element
+of illusion in perception. The physicist, by reducing all external
+changes to "modes of motion," appears to leave no room in his
+world-mechanism for the secondary qualities of bodies, such as light
+and heat, as popularly conceived. Yet, while allowing this, I think we
+may still regard the attribution of qualities like colour to objects as
+in the main correct and answering to a real fact. When a person says an
+object is red, he is understood by everybody as affirming something
+which is true or false, something therefore which either involves an
+external fact or is illusory. It would involve an external fact whenever
+the particular sensation which he receives is the result of a physical
+action (other vibrations of a certain order), which would produce a like
+sensation in anybody else in the same situation and endowed with the
+normal retinal sensibility. On the other hand, an illusory attribution
+of colour would imply that there is no corresponding physical agency at
+work in the case, but that the sensation is connected with exceptional
+individual conditions, as, for example, altered retinal sensibility.
+
+We are now, perhaps, in a position to frame a rough definition of an
+illusion of perception as popularly understood. A large number of such
+phenomena may be described as consisting in the formation of percepts or
+quasi-percepts in the minds of individuals under external circumstances
+which would not give rise to similar percepts in the case of other
+people.
+
+A little consideration, however, will show that this is not an adequate
+definition of what is ordinarily understood by an illusion of sense.
+There are special circumstances which are fitted to excite a momentary
+illusion in all minds. The optical illusions due to the reflection and
+refraction of light are not peculiar to the individual, but arise in all
+minds under precisely similar external conditions.
+
+It is plain that the illusoriness of a perception is in these cases
+determined in relation to the sense-impressions of other moments and
+situations, or to what are presumably better percepts than the present
+one. Sometimes this involves an appeal from one sense to another. Thus,
+there is the process of verification of sight by touch, for example, in
+the case of optical images, a mode of perception which, as we have seen,
+gives a more direct cognition of external quality. Conversely, there may
+occasionally be a reference from touch to sight, when it is a question
+of discriminating two points lying very close to one another. Finally,
+the same sense may correct itself, as when the illusion of the
+stereoscope is corrected by afterwards looking at the two separate
+pictures.
+
+We may thus roughly define an illusion of perception as consisting in
+the formation of a quasi-percept which is peculiar to an individual, or
+which is contradicted by another and presumably more accurate percept.
+Or, if we take the meaning of the word common to include both the
+universal as contrasted with the individual experience, and the
+permanent, constant, or average, as distinguished from the momentary and
+variable percept, we may still briefly describe an illusion of
+perception as a deviation from the common or collective experience.
+
+
+_Sources of Sense-Illusion._
+
+Understanding sense-illusion in this way, let us glance back at the
+process of perception in its several stages or aspects, with the object
+of discovering what room occurs for illusion.
+
+It appears at first as if the preliminary stages--the reception,
+discrimination, and classification of an impression--would not offer the
+slightest opening for error. This part of the mechanism of perception
+seems to work so regularly and so smoothly that one can hardly conceive
+a fault in the process. Nevertheless, a little consideration will show
+that even here all does not go on with unerring precision.
+
+Let us suppose that the very first step is wanting--distinct attention
+to an impression. It is easy to see that this will favour illusion by
+leading to a confusion of the impression. Thus the timid man will more
+readily fall into the illusion of ghost-seeing than a cool-headed
+observant man, because he is less attentive to the actual impression of
+the moment. This inattention to the sense-impression will be found to be
+a great co-operating factor in the production of illusions.
+
+But if the sensation is properly attended to, can there be error through
+a misapprehension of what is actually in the mind at the moment? To say
+that there can may sound paradoxical, and yet in a sense this is
+demonstrable. I do not mean that there is an observant mind behind and
+distinct from the sensation, and failing to observe it accurately
+through a kind of mental short-sightedness. What I mean is that the
+usual psychical effect of the incoming nervous process may to some
+extent be counteracted by a powerful reaction of the centres. In the
+course of our study of illusions, we shall learn that it is possible for
+the quality of an impression, as, for example, of a sensation of colour,
+to be appreciably modified when there is a strong tendency to regard it
+in one particular way.
+
+Postponing the consideration of these, we may say that certain illusions
+appear clearly to take their start from an error in the process of
+classifying or identifying a present impression. On the physical side,
+we may say that the first stages of the nervous process, the due
+excitation of the sensory centre in accordance with the form of the
+incoming stimulation and the central reaction involved in the
+recognition of the sensation, are incomplete. These are so limited and
+comparatively unimportant a class, that it will be well to dispose of
+them at once.
+
+
+_Confusion of the Sense-Impression._
+
+The most interesting case of such an error is where the impression is
+unfamiliar and novel in character. I have already remarked that in the
+mental life of the adult perfectly new sensations never occur. At the
+same time, comparatively novel impressions sometimes arise. Parts of the
+sensitive surface of the body which rarely undergo stimulation are
+sometimes acted on, and at other times they receive partially new modes
+of stimulation. In such cases it is plain that the process of classing
+the sensation or recognizing it is not completed. It is found that
+whenever this happens there is a tendency to exaggerate the intensity of
+the sensation. The very fact of unfamiliarity seems to give to the
+sensation a certain exciting character. As something new and strange, it
+for the instant slightly agitates and discomposes the mind. Being unable
+to classify it with its like, we naturally magnify its intensity, and
+so tend to ascribe it to a disproportionately large cause.
+
+For instance, a light bandage worn about the body at a part usually free
+from pressure is liable to be conceived as a weighty mass. The odd sense
+of a big cavity in the mouth, which we experience just after the loss of
+a tooth, is probably another illustration of this principle. And a third
+example may also be supplied from the recollection of the dentist's
+patient, namely, the absurd imagination which he tends to form as to
+what is actually going on in his mouth when a tooth is being bored by a
+modern rotating drill. It may be found that the same principle helps to
+account for the exaggerated importance which we attach to the
+impressions of our dreams.
+
+It is evident that all indistinct impressions are liable to be wrongly
+classed. Sensations answering to a given colour or form, are, when
+faint, easily confused with other sensations, and so an opening occurs
+for illusion. Thus, the impressions received from distant objects are
+frequently misinterpreted, and, as we shall see by-and-by, it is in this
+region of hazy impression that imagination is wont to play its most
+startling pranks.
+
+It is to be observed that the illusions arising from wrong
+classification will be more frequent in the case of those senses where
+discrimination is low. Thus, it is much easier in a general way to
+confuse two sensations of smell than two sensations of colour. Hence the
+great source of such errors is to be found in that mass of obscure
+sensation which is connected with the organic processes, as digestion,
+respiration, etc., together with those varying tactual and motor
+feelings, which result from what is called the subjective stimulation of
+the tactual nerves, and from changes in the position and condition of
+the muscles. Lying commonly in what is known as the sub-conscious region
+of mind, undiscriminated, vague, and ill-defined, these sensations, when
+they come to be specially attended to, readily get misapprehended, and
+so lead to illusion, both in waking life and in sleep. I shall have
+occasion to illustrate this later on.
+
+With these sensations, the result of stimulations coming from remote
+parts of the organism, may be classed the ocular impressions which we
+receive in indirect vision. When the eye is not fixed on an object, the
+impression, involving the activity of some-peripheral region of the
+retina, is comparatively indistinct. This will be much more the case
+when the object lies at a distance for which the eye is not at the time
+accommodated. And in these circumstances, when we happen to turn our
+attention to the impression, we easily misapprehend it, and so fall into
+illusion. Thus, it has been remarked by Sir David Brewster, in his
+_Letters on Natural Magic_ (letter vii.), that when looking through a
+window at some object beyond, we easily suppose a fly on the window-pane
+to be a larger object, as a bird, at a greater distance.[15]
+
+While these cases of a confusion or a wrong classification of the
+sensation are pretty well made out, there are other illusions or
+quasi-illusions respecting which it is doubtful whether they should be
+brought under this head. For example, it was found by Weber, that when
+the legs of a pair of compasses are at a certain small distance apart
+they will be felt as two by some parts of the tactual surface of the
+body, but only as one by other parts. How are we to regard this
+discrepancy? Must we say that in the latter case there are two
+sensations, only that, being so similar, they are confused one with
+another? There seems some reason for so doing, in the fact that, by a
+repeated exercise of attention to the experiment, they may afterwards be
+recognized as two.
+
+We here come on the puzzling question, How much in the character of the
+sensation must be regarded as the necessary result of the particular
+mode of nervous stimulation at the moment, together with the laws of
+sensibility, and how much must be put down to the reaction of the mind
+in the shape of attention and discrimination? For our present purpose we
+may say that, whenever a deliberate effort of attention does not suffice
+to alter the character of a sensation, this may be pretty safely
+regarded as a net result of the nervous process, and any error arising
+may be referred to the later stages of the process of perception. Thus,
+for example, the taking of the two points of a pair of compasses for
+one, where the closest attention does not discover the error, is best
+regarded as arising, not from a confusion of the sense-impression, but
+from a wrong interpretation of a sensation, occasioned by an
+overlooking of the limits of local discriminative sensibility.
+
+
+_Misinterpretation of the Sense-Impression._
+
+Enough has been said, perhaps, about those errors of perception which
+have their root in the initial process of sensation. We may now pass to
+the far more important class of illusions which are related to the later
+stages of perception, that is to say, the process of interpreting the
+sense-impression. Speaking generally, one may describe an illusion of
+perception as a misinterpretation. The wrong kind of interpretative
+mental image gets combined with the impression, or, if with Helmholtz we
+regard perception as a process of "unconscious inference," we may say
+that these illusions involve an unconscious fallacious conclusion. Or,
+looking at the physical side of the operation, it may be said that the
+central course taken by the nervous process does not correspond to the
+external relations of the moment.
+
+As soon as we inspect these illusions of interpretation, we see that
+they fall into two divisions, according as they are connected with the
+process of _suggestion_, that is to say, the formation of the
+interpretative image so far as determined by links of association with
+the actual impression, or with an independent process of _preperception_
+as explained above. Thus, for example, we fall into the illusion of
+hearing two voices when our shout is echoed back, just because the
+second auditory impression irresistibly calls up the image of a second
+shouter. On the other hand, a man experiences the illusion of seeing
+spectres of familiar objects just after exciting his imagination over a
+ghost-story, because the mind is strongly predisposed to frame this kind
+of percept. The first class of illusions arises from without, the
+sense-impression being the starting-point, and the process of
+preperception being controlled by this. The second class arises rather
+from within, from an independent or spontaneous activity of the
+imagination. In the one case the mind is comparatively passive; in the
+other it is active, energetically reacting on the impression, and
+impatiently anticipating the result of the normal process of
+preperception. Hence I shall, for brevity's sake, commonly speak of them
+as Passive and Active Illusions.[16]
+
+I may, perhaps, illustrate these two classes of illusion by the simile
+of an interpreter poring over an old manuscript. The first would be due
+to some peculiarity in the document misleading his judgment, the second
+to some caprice or preconceived notion in the interpreter's mind.
+
+It is not difficult to define conjecturally the physiological conditions
+of these two large classes of illusion. On the physical side, an
+illusion of sense, like a just perception, is the result of a fusion of
+the nervous process answering to a sensation with a nervous process
+answering to a mental image. In the case of passive illusions, this
+fusion may be said to take place in consequence of some point of
+connection between the two. The existence of such a connection appears
+to be involved in the very fact of suggestion, and may be said to be
+the organic result of frequent conjunctions of the two parts of the
+nervous operation in our past history. In the case of active illusions,
+however, which spring rather from the independent energy of a particular
+mode of the imagination, this point of organic connection is not the
+only or even the main thing. In many cases, as we shall see, there is
+only a faint shade of resemblance between the present impression and the
+mental image with which it is overlaid. The illusions dependent on
+vivid, expectation thus answer much less to an objective conjunction of
+past experiences than to a capricious subjective conjunction of mental
+images. Here, then, the fusion of nervous processes must have another
+cause. And it is not difficult to assign such a cause. The antecedent
+activity of imagination doubtless involves as its organic result a
+powerful temporary disposition in the nervous structures concerned to go
+on acting. In other words, they remain in a state of sub-excitation,
+which can be raised to full excitation by a slight additional force. The
+more powerful this disposition in the centres involved in the act of
+imagination, the less the additional force of external stimulus required
+to excite them to full activity.
+
+Considering the first division, passive illusions, a little further, we
+shall see that they may be broken up into two sub-classes, according to
+the causes of the errors. In a general way we assume that the impression
+always answers to some quality of the object which is perceived, and
+varies with this; that, for example, our sensation of colour invariably
+represents the quality of external colour which we attribute to the
+object. Or, to express it physically, we assume that the external force
+acting on the sense-organ invariably produces the same effect, and that
+the effect always varies with the external cause. But this assumption,
+though true in the main, is not perfectly correct. It supposes that the
+organic conditions are constant, and that the organic process faithfully
+reflects the external operation. Neither of these suppositions is
+strictly true. Although in general we may abstract from the organism and
+view the relation between the external fact and the mental impression as
+direct, we cannot always do so.
+
+This being so, it is possible for errors of perception to arise through
+peculiarities of the nervous organization itself. Thus, as I have just
+observed, sensibility has its limits, and these limits are the
+starting-point in a certain class of widely shared or _common_
+illusions. An example of this variety is the taking of the two points of
+a pair of compasses for one by the hand, already referred to. Again, the
+condition of the nervous structures varies indefinitely, so that one and
+the same stimulus may, in the case of two individuals, or of the same
+individual at different times, produce widely unlike modes of sensation.
+Such variations are clearly fitted to lead to gross _individual_ errors
+as to the external cause of the sensation. Of this sort is the illusory
+sense of temperature which we often experience through a special state
+of the organ employed.
+
+While there are these errors of interpretation due to some peculiarity
+of the organization, there are others which involve no such peculiarity,
+but arise through the special character or exceptional conformation of
+the environment at the moment. Of this order are the illusions connected
+with the reflection of light and sound. We may, perhaps, distinguish the
+first sub-class as organically conditioned illusions, and the second as
+extra-organically determined illusions. It may be added that the latter
+are roughly describable as common illusions. They thus answer in a
+measure to the first variety of organically conditioned illusions,
+namely, those connected with the limits of sensibility. On the other
+hand, the active illusions, being essentially individual or subjective,
+may be said to correspond to the other variety of this class--those
+connected with variations of sensibility.
+
+Our scheme of sense-illusions is now complete. First of all, we shall
+take up the passive illusions, beginning with those which are
+conditioned by special circumstances in the organism. After that we
+shall illustrate those which depend on peculiar circumstances in the
+environment. And finally, we shall separately consider what I have
+called the active illusions of sense.
+
+It is to be observed that these illusions of perception properly so
+called, namely, the errors arising from a wrong interpretation of an
+impression, and, not from a confusion of one impression with another are
+chiefly illustrated in the region of the two higher senses, sight and
+hearing. For it is here, as we have seen, that the interpretative
+imagination has most work to do in evolving complete percepts of
+material, tangible objects, having certain relations in space, out of a
+limited and homogeneous class of sensations, namely, those of light and
+colour, and of sound. As I have before observed, tactual perception, in
+so far as it is the recognition of an object of a certain size,
+hardness, and distance from our body, involves the least degree of
+interpretation, and so offers little room for error; it is only when
+tactual perception amounts to the _recognition_ of an individual object,
+clothed with secondary as well as primary qualities, that an opening for
+palpable error occurs.
+
+With respect, however, to the first sub-class of these illusions,
+namely, those arising from organic peculiarities which give a twist, so
+to speak, to the sensation, no very marked contrast between the
+different senses presents itself. So that in illustrating this group we
+shall be pretty equally concerned with the various modes of perception
+connected with the different senses.
+
+It may be said once for all that in thus marking off from one another
+certain groups of illusion, I am not unmindful of the fact that these
+divisions answer to no very sharp natural distinctions. In fact, it will
+be found that one class gradually passes into the other, and that the
+different characteristics here separated often combine in a most
+perplexing way. All that is claimed for this classification is that it
+is a convenient mode of mapping out the subject.
+
+
+
+
+CHAPTER IV.
+
+ILLUSIONS OF PERCEPTION--_continued_.
+
+A. _Passive Illusions (a) as determined by the Organism._
+
+
+In dealing with the illusions which are related to certain peculiarities
+in the nervous organism and the laws of sensibility, I shall commence
+with those which are connected with certain limits of sensibility.
+
+
+_Limits of Sensibility._
+
+To begin with, it is known that the sensation does not always answer to
+the external stimulus in its degree or intensity. Thus, a certain amount
+of stimulation is necessary before any sensation arises. And this will,
+of course, be greater when there is little or no attention directed to
+the impression, that is to say, no co-operating central reaction. Thus
+it happens that slight stimuli go overlooked, and here illusion may have
+its starting-point. The most familiar example of such slight errors is
+that of movement. When we are looking at objects, our ocular muscles are
+apt to execute very slight movements which escape our notice. Hence we
+tend, under certain circumstances, to carry over the retinal result of
+the movement, that is to say, the impression produced by a shifting of
+the parts of the retinal image to new nervous elements, to the object
+itself, and so to transform a "subjective" into an "objective" movement.
+In a very interesting work on apparent or illusory movements, Professor
+Hoppe has fully investigated the facts of such slight movements, and
+endeavoured to specify their causes.[17]
+
+Again, even when the stimulus is sufficient to produce a conscious
+impression, the degree of the feeling may not represent the degree of
+the stimulus. To take a very inconspicuous case, it is found by Fechner
+that a given increase of force in the stimulus produces a less amount of
+difference in the resulting sensations when the original stimulus is a
+powerful one than when it is a feeble one. It follows from this, that
+differences in the degree of our sensations do not exactly correspond to
+objective differences. For example, we tend to magnify the differences
+of light among objects, all of which are feebly illuminated, that is to
+say, to see them much more removed from one another in point of
+brightness than when they are more strongly illuminated. Helmholtz
+relates that, owing to this tendency, he has occasionally caught
+himself, on a dark night, entertaining the illusion that the
+comparatively bright objects visible in twilight were self-luminous.[18]
+
+Again, there are limits to the conscious separation of sensations which
+are received together, and this fact gives rise to illusion. In general,
+the number of distinguishable sensations answers to the number of
+external causes; but this is not always the case, and here we naturally
+fall into the error of mistaking the number of the stimuli. Reference
+has already been made to this fact in connection with the question
+whether consciousness can be mistaken as to the character of a present
+feeling.
+
+The case of confusing two impressions when the sensory fibres involved
+are very near one another, has already been alluded to. Both in touch
+and in sight we always take two or more points for one when they are
+only separated by an interval that falls below the limits of local
+discrimination. It seems to follow from this that our perception of the
+world as a continuum, made up of points perfectly continuous one with
+another may, for what we know, be illusory. Supposing the universe to
+consist of atoms separated by very fine intervals, then it is
+demonstrable that it would appear to our sensibility as a continuum,
+just as it does now.[19]
+
+Two or more simultaneous sensations are indistinguishable from one
+another, not only when they have nearly the same local origin, but under
+other circumstances. The blending of partial sensations of tone in a
+_klang_-sensation, and the coalescence in certain cases of the
+impressions received by way of the two retinas, are examples of this. It
+is not quite certain what determines this fusion of two simultaneous
+feelings. It may be said generally that it is favoured by similarity
+between the sensations;[20] by a comparative feebleness of one of the
+feelings; by the fact of habitual concomitance, the two sensations
+occurring rarely, if ever, in isolation; and by the presence of a mental
+disposition to view them as answering to one external object. These
+considerations help us to explain the coalescence of the retinal
+impressions and its limits, the fusion of partial tones, and so on.[21]
+
+It is plain that this fusion of sensations, whatever its exact
+conditions may be, gives rise to error or wrong interpretation of the
+sense-impression. Thus, to take the points of two legs of a pair of
+compasses for one point is clearly an illusion of perception. Here is
+another and less familiar example. Very cold and smooth surfaces, as
+those of metal, often appear to be wet. I never feel sure, after wiping
+the blades of my skates, that they are perfectly dry, since they always
+seem more or less damp to my hand. What is the reason of this? Helmholtz
+explains the phenomenon by saying that the feeling we call by the name
+of wetness is a compound sensation consisting of one of temperature and
+one of touch proper. These sensations occurring together so frequently,
+blend into one, and so we infer, according to the general instinctive
+tendency already noticed, that there is one specific quality answering
+to the feeling. And since the feeling is nearly always produced by
+surfaces moistened by cold liquid, we refer it to this circumstance, and
+speak of it as a feeling of wetness. Hence, when the particular
+conjunction of sensations arises apart from this external circumstance,
+we erroneously infer its presence.[22]
+
+The most interesting case of illusion connected with the fusion of
+simultaneous sensations, is that of single vision, or the deeply
+organized habit of combining the sensations of what are called the
+corresponding points of the two retinas. This coalescence of two
+sensations is so far erroneous since it makes us overlook the existence
+of two distinct external agencies acting on different parts of the
+sensitive surface of the body. And this is the more striking in the case
+of looking at solid objects, since here it is demonstrable that the
+forces acting on the two retinas are not perfectly similar.
+Nevertheless, such a coalescence plainly answers to the fact that these
+external agencies usually arise in one and the same object, and this
+unity of the object is, of course, the all-important thing to be sure
+of.
+
+This habit may, however, beget palpable illusion in another way. In
+certain exceptional cases the coalescence does not take place, as when I
+look at a distant object and hold a pencil just before my eyes.[23] And
+in this case the organized tendency to take one visual impression for
+one object asserts its force, and I tend to fall into the illusion of
+seeing two separate pencils. If I do not wholly lapse into the error, it
+is because my experience has made me vaguely aware that double images
+under these circumstances answer to one object, and that if there were
+really two pencils present I should have four visual impressions.
+
+Once more, it is a law of sensory stimulation that an impression
+persists for an appreciable time after the cessation of the action of
+the stimulus. This "after sensation" will clearly lead to illusion, in
+so far as we tend to think of the stimulus as still at work. It forms,
+indeed, as will be seen by-and-by, the simplest and lowest stage of
+hallucination. Sometimes this becomes the first stage of a palpable
+error. After listening to a child crying for some time the ear easily
+deceives itself into supposing that the noise is continued when it has
+actually ceased. Again, after taking a bandage from a finger, the
+tingling and other sensations due to the pressure sometimes persist for
+a good time, in which case they easily give rise to an illusion that the
+finger is still bound.
+
+It follows from this fact of the reverberation of the nervous structures
+after the removal of a stimulus, that whenever two discontinuous
+stimulations follow one another rapidly enough, they will appear
+continuous. This fact is a fruitful source of optical illusion. The
+appearance of a blending of the stripes of colours on a rotating disc or
+top, of the formation of a ring of light by swinging round a piece of
+burning wood, and the illusion of the toy known as the thaumatrope, or
+wheel of life, all depend on this persistence of retinal impression.
+Many of the startling effects of sleight of hand are undoubtedly due in
+part to this principle. If two successive actions or sets of
+circumstances to which the attention of the spectator is specially
+directed follow one another by a very narrow interval of time, they
+easily appear continuous, so that there seems absolutely no time for the
+introduction of an intermediate step.[24]
+
+There is another limit to sensibility which is in a manner the opposite
+to the one just named. It is a law of nervous stimulation that a
+continued activity of any structure results in less and less psychic
+result, and that when a stimulus is always at work it ceases in time to
+have any appreciable effect. The common illustration of this law is
+drawn from the region of sound. A constant noise, as of a mill, ceases
+to produce any conscious sensation. This fact, it is plain, may easily
+become the commencement of an illusion. Not only may we mistake a
+measure of noise for perfect silence,[25] we may misconceive the real
+nature of external circumstances by overlooking some continuous
+impression.
+
+Curious illustrations of this effect are found in optical illusions,
+namely, the errors we make respecting the movement of stationary objects
+after continued movement of the eyes. When, for example, in a railway
+carriage we have for some time been following the (apparent) movement of
+objects, as trees, etc., and turn our eyes to an apparently stationary
+object, as the carpet of the compartment, this seems to move in the
+contrary direction to that of the trees. Helmholtz's explanation of this
+illusion is that when we suppose that we are fixing our eye on the
+carpet we are really continuing to move it over the surface by reason of
+the organic tendency, already spoken of, to go on doing anything that
+has been done. But since we are unaware of this prolonged series of
+ocular movements, the muscular feelings having become faint, we take the
+impression produced by the sliding of the picture over the retina to be
+the result of a movement of the object.[26]
+
+Another limit to our sensibility, which needs to be just touched on
+here, is known by the name of the specific energy of the nerves. One and
+the same nerve-fibre always reacts in a precisely similar way, whatever
+the nature of the stimulus. Thus, when the optic nerve is stimulated in
+any manner, whether by light, mechanical pressure, or an electric
+current, the same effect, a sensation of light, follows.[27] In a usual
+way, a given class of nerve-fibre is only stimulated by one kind of
+stimulus. Thus, the retina, in ordinary circumstances, is stimulated by
+light. Owing to this fact, there has arisen a deeply organized habit of
+translating the impression in one particular way. Thus, I instinctively
+regard a sensation received by means of the optic nerve as one caused by
+light.
+
+Accordingly, whenever circumstances arise in which a like sensation is
+produced by another kind of stimulus, we fall into illusion. The
+phosphenes, or circles of light which are seen when the hinder part of
+the eyeball is pressed, may be said to be illusory in so far as we
+speak of them as perceptions of light, thus referring them to the
+external physical agency which usually causes them. The same remark
+applies to those "subjective sensations," as they are called, which are
+known to have as their physical cause subjective stimuli, consisting, in
+the case of sight, in varying conditions of the peripheral organ, as
+increased blood-pressure. Strictly speaking, such simple feelings as
+these appear to be, involve an ingredient of false perception: in saying
+that we _perceive_ light at all, we go beyond the pure sensation,
+interpreting this wrongly.
+
+Very closely connected with this limitation of our sensibility is
+another which refers to the consciousness of the local seat, or origin
+of the impression. This has so far its basis in the sensation itself as
+it is well known that (within the limits of local discrimination,
+referred to above) sensations have a particular "local" colour, which
+varies in the case of each of the nervous fibres by the stimulation of
+which they arise.[28] But though this much is known through a difference
+in the sensibility, nothing more is known. Nothing can certainly be
+ascertained by a mere inspection of the sensation as to the distance the
+nervous process has travelled, whether from the peripheral termination
+of the fibre or from some intermediate point.
+
+In a general way, we refer our sensations to the peripheral endings of
+the nerves concerned, according to what physiologists have called "the
+law of eccentricity." Thus I am said to feel the pain caused by a
+bruise in the foot in the member itself. This applies also to some of
+the sensations of the special senses. Thus, impressions of taste are
+clearly localized in the corresponding peripheral terminations.
+
+With respect to the sense of smell, and still more to those of hearing
+and sight, where the impression is usually caused by an object at a
+distance from the peripheral organ, our attention to this external cause
+leads us to overlook in part the "bodily seat" of the sensation. Yet
+even here we are dimly aware that the sensation is received by way of a
+particular part of the sensitive surface, that is to say, by a
+particular sense-organ. Thus, though referring an odour to a distant
+flower, we perceive that the sensation of odour has its bodily origin in
+the nose. And even in the case of hearing and sight, we vaguely refer
+the impressions, as such, to the appropriate sense-organ. There is,
+indeed, in these cases a double local reference, a faint one to the
+peripheral organ which is acted on, and a more distinct one to the
+object or the force in the environment which acts on this.
+
+Now, it may be said that the act of localization is in itself distinctly
+illusory, since it is known that the sensation first arises in
+connection with the excitation of the sensory _centre_, and not of the
+peripheral fibre.[29] Yet it must at least be allowed that this
+localization of sensation answers to the important fact that, under
+usual circumstances, the agency producing the sensation is applied at
+this particular point of the organism, the knowledge of which point is
+supposed by modern psychologists to have been very slowly learnt by the
+individual and the race, through countless experiments with the moving
+organ of touch, assisted by the eye.
+
+Similarly, the reference of the impression, in the case of hearing and
+sight, to an object in the environment, though, as we have seen, from
+one point of view illusory, clearly answers to a fact of our habitual
+experience; for in an immense preponderance of cases at least a visual
+or auditory impression does arise through the action on the sense-organ
+of a force (ether or air waves) proceeding from a distant object.
+
+In some circumstances, however, even this element of practical truth
+disappears, and the localization of the impression, both within and
+without the organism, becomes altogether illusory. This result is
+involved in the illusions, already spoken of, which arise from the
+instinctive tendency to refer sensations to the ordinary kind of
+stimulus. Thus, when a feeling resulting from a disturbance in the optic
+nerve is interpreted as one of external light vaguely felt to be acting
+on the eye, or one resulting from some action set up in the auditory
+fibre as a sensation of external sound vaguely felt to be entering the
+ear, we see that the error of localization is a consequence of the other
+error already characterized.
+
+As I have already observed, an excitation of a nerve at any other point
+than the peripheral termination, occurs but rarely in normal life. One
+familiar instance is the stimulation of the nerve running to the hand
+and fingers, by a sharp blow on the elbow over which it passes. As
+everybody knows, this gives rise to a sense of pain at the _extremities_
+of the nerve. The most common illustration of such errors of
+localization is found in subjective sensations, such as the impression
+we sometimes have of something creeping over the skin, of a disagreeable
+taste in the mouth, of luminous spots floating across the field of
+vision, and so on. The exact physiological seat of these is often a
+matter of conjecture only; yet it may safely be said that in many
+instances the nervous excitation originates at some point considerably
+short of its peripheral extremity: in which case there occurs the
+illusion of referring the impressions to the peripheral sense-organ, and
+to an external force acting on this.
+
+The most striking instances of these errors of localization are found in
+abnormal circumstances. It is well known that a man who has lost a leg
+refers all sensations arising from a stimulation of the truncated fibres
+to his lost foot, and in some cases has even to convince himself of the
+non-existence of his lost member by sight or touch. Patients often
+describe these experiences in very odd language. "If," says one of Dr.
+Weir Mitchell's patients, "I should say I am more sure of the leg which
+ain't than the one which air, I guess I should be about correct."[30]
+
+There is good reason for supposing that this source of error plays a
+prominent part in the illusions of the insane. Diseased centres may be
+accompanied by disordered peripheral structures, and so subjective
+sensation may frequently be the starting-point of the wildest illusions.
+Thus, a patient's horror of poison may have its first origin in some
+subjective gustatory sensation. Similarly, subjective tactual sensations
+may give rise to gross illusions, as when a patient "feels" his body
+attacked by foul and destructive creatures.
+
+It may be well to remark that this mistaken interpretation of the seat
+or origin of subjective sensation is closely related to hallucination.
+In so far as the error involves the ascription of the sensation to a
+force external to the sense-organ, this part of the mental process must,
+when there is no such force present, be viewed as hallucinatory. Thus,
+the feeling of something creeping over the skin is an hallucination in
+the sense that it implies the idea of an object external to the skin.
+Similarly, the projection of an ocular impression due to retinal
+disturbance into the external field of vision, may rightly be named an
+hallucination. But the case is not always so clear as this. Thus, for
+example, when a gustatory sensation is the result of an altered
+condition of the saliva, it may be said that the error is as much an
+illusion as an hallucination.[31]
+
+In a wide sense, again, all errors connected with those subjective
+sensations which arise from a stimulation of the peripheral regions of
+the nerve may be called illusions rather than hallucinations. Or, if
+they must be called hallucinations, they may be distinguished as
+"peripheral" from those "central" hallucinations which arise through an
+internal automatic excitation of the sensory centre. It is plain from
+this that the region of subjective sensation is an ambiguous region,
+where illusion and hallucination mix and become confused. To this point
+I shall have occasion to return by-and-by.
+
+I have now probably said enough respecting the illusions that arise
+through the fact of there being fixed limits to our sensibility. The
+_rationale_ of these illusions is that whenever the limit is reached, we
+tend to ignore it and to interpret the impression in the customary way.
+
+
+_Variations of Sensibility._
+
+We will now pass to a number of illusions which depend on something
+variable in the condition of our sensibility, or some more or less
+exceptional organic circumstance. These variations may be momentary and
+transient or comparatively permanent. The illusion arises in each case
+from our ignoring the variation, and treating a given sensation under
+all circumstances as answering to one objective cause.
+
+First of all, the variation of organic state may affect our mental
+representation of the strength of the stimulus or external cause. Here
+the fluctuation may be a temporary or a permanent one. The first case is
+illustrated in the familiar example of taking a room to be brighter
+than it is when emerging from a dark one. Another striking example is
+that of our sense of the temperature of objects, which is known to be
+strictly relative to a previous sensation, or more correctly to the
+momentary condition of the organ. Yet, though every intelligent person
+knows this, the deeply rooted habit of making sensation the measure of
+objective quality asserts its sway, and frequently leads us into
+illusion. The well-known experiment of first plunging one hand in cold
+water, the other in hot, and then dipping them both in tepid, is a
+startling example of this organized tendency. For here we are strongly
+disposed to accept the palpable contradiction that the same water is at
+once warm and cool.
+
+Far more important than these temporary fluctuations of sensibility are
+the permanent alterations. Excessive fatigue, want of proper nutrition,
+and certain poisons are well known to be causes of such changes. They
+appear most commonly under two forms, exalted sensibility, or
+hyperæsthesia, and depressed sensibility, or anæsthesia. In these
+conditions flagrant errors are made as to the real magnitude of the
+causes of the sensations. These variations may occur in normal life to
+some extent. In fairly good health we experience at times strange
+exaltations of tactual sensibility, so that a very slight stimulus, such
+as the contact of the bed-clothes, becomes greatly exaggerated.
+
+In diseased states of the nervous system these variations of sensibility
+become much more striking. The patient who has hyperæsthesia fears to
+touch a perfectly smooth surface, or he takes a knock at the door to be
+a clap of thunder. The hypochondriac may, through an increase of
+organic sensibility, translate organic sensations as the effect of some
+living creature gnawing at his vitals. Again, states of anæsthesia lead
+to odd illusions among the insane. The common supposition that the body
+is dead, or made of wood or of glass, is clearly referable in part to
+lowered sensibility of the organism.[32]
+
+It is worth adding, perhaps, that these variations in sensibility give
+rise not only to sensory but also to motor illusions. To take a homely
+instance, the last miles of a long walk seem much longer than the first,
+not only because the sense of fatigue leading us to dwell on the
+transition of time tends to magnify the apparent duration, but because
+the fatigued muscles and connected nerves yield a new set of sensations
+which constitute an exaggerated standard of measurement. A number of
+optical illusions illustrate the same thing. Our visual sense of
+direction is determined in part by the feelings accompanying the action
+of the ocular muscles, and so is closely connected with the perception
+of movement, which has already been touched on. If an ocular muscle is
+partially paralyzed it takes a much greater "effort" to effect a given
+extent of movement than when the muscle is sound. Hence any movement
+performed by the eye seems exaggerated. Hence, too, in this condition
+objects are seen in a wrong direction; for the patient reasons that they
+are where they would seem to be if he had executed a wider movement than
+he really has. This may easily be proved by asking him to try to seize
+the object with, his hand. The effect is exaggerated when complete
+paralysis sets in, and no actual movement occurs in obedience to the
+impulse from within.[33]
+
+Variations in the condition of the nerve affect not only the degree, but
+also the quality of the sensation, and this fact gives rise to a new
+kind of illusion. The curious phenomena of colour-contrast illustrate
+momentary alterations of sensibility. When, after looking at a green
+colour for a time, I turn my eye to a grey surface and see this of the
+complementary rose-red hue, the effect is supposed to be due to a
+temporary fatigue of the retina in relation to those ingredients of the
+total light in the second case which answer to the partial light in the
+first (the green rays).[34]
+
+These momentary modifications of sensibility are of no practical
+significance, being almost instantly corrected. Other modifications are
+more permanent. It was found by Himly that when the retina is
+overexcitable every stimulus is raised in the spectrum scale of colours.
+Thus, violet becomes red. An exactly opposite effect is observed when
+the retina is torpid.[35] Certain poisons are known to affect the
+quality of the colour-impression. Thus, santonin, when taken in any
+quantity, makes all colourless objects look yellow. Severe pathological
+disturbances are known to involve, in addition to hyperæsthesia and
+anæsthesia, what, has been called paræsthesia, that is to say, that
+condition in which the quality of sensation is greatly changed. Thus,
+for example, to one in this state all food appears to have a metallic
+taste, and so on.
+
+If we now glance back at the various groups of illusions just
+illustrated, we find that they all have this feature in common: they
+depend on the general mental law that when we have to do with the
+unfrequent, the unimportant, and therefore unattended to, and the
+exceptional, we employ the ordinary, the familiar, and the well-known as
+our standard. Thus, whether we are dealing with sensations that fall
+below the ordinary limits of our mental experience, or with those which
+arise in some exceptional state of the organism, we carry the habits
+formed in the much wider region of average every-day perception with us.
+In a word, illusion in these cases always arises through what may,
+figuratively at least, be described as the application of a rule, valid
+for the majority of cases, to an exceptional case.
+
+In the varieties of illusion just considered, the circumstance that
+gives the peculiarity to the case thus wrongly interpreted has been
+referred to the organism. In the illusions to which we now pass, it will
+be referred to the environment. At the same time, it is plain that there
+is no very sharp distinction between the two classes. Thus, the visual
+illusion produced by pressing the eyeball might be regarded not only as
+the result of the organic law of the "specific energy" of the nerves,
+but, with almost equal appropriateness, as the consequence of an
+exceptional state of things in the environment, namely, the pressure of
+a body on the retina. As I have already observed, the classification
+here adopted is to be viewed simply as a rough expedient for securing
+something like a systematic review of the phenomena.
+
+
+
+
+CHAPTER V.
+
+ILLUSIONS OF PERCEPTION--_continued_.
+
+A. _Passive Illusions (b) as determined by the Environment._
+
+
+In the following groups of illusion we may look away from nervous
+processes and organic disturbances, regarding the effect of any external
+stimulus as characteristic, that is, as clearly marked off from the
+effects of other stimuli, and as constant for the same stimulus. The
+source of the illusion will be looked for in something exceptional in
+the external circumstances, whereby one object or condition of an object
+imitates the effect of another object or condition, to which, owing to a
+large preponderance of experience, we at once refer it.
+
+
+_Exceptional Relation of Stimulus to Organ._
+
+A transition from the preceding to the following class of illusions is
+to be met with in those errors which arise from a very exceptional
+relation between the stimulus and the organ of sense. Such a state of
+things is naturally interpreted by help of more common and familiar
+relations, and so error arises.
+
+For example, we may grossly misinterpret the intensity of a stimulus
+under certain circumstances. Thus, when a man crunches a biscuit, he has
+an uncomfortable feeling that the noise as of all the structures of his
+head being violently smashed is the same to other ears, and he may even
+act on his illusory perception, by keeping at a respectful distance from
+all observers. And even though he be a physiologist, and knows that the
+force of sensation in this case is due to the propagation of vibrations
+to the auditory centre by other channels than the usual one of the ear,
+the deeply organized impulse to measure the strength of an external
+stimulus by the intensity of the sensation asserts its force.
+
+Again, if we turn to the process of perceptional construction properly
+so called, the reference of the sensation to a material object lying in
+a certain direction, etc., we find a similar transitional form of
+illusion. The most interesting case of this in visual perception is that
+of a disturbance or displacement of the organ by external force. For
+example, an illusory sense of direction arises by the simple action of
+closing one eye, say the left, and pressing the other eyeball with one
+of the fingers a little outwards, that is to the right. The result of
+this movement is, of course, to transfer the retinal picture to new
+nervous elements further to the right. And since, in this instance, the
+displacement is not produced in the ordinary way by the activity of the
+ocular muscle making itself known by certain feelings of movement, it is
+disregarded altogether, and the direction of the objects is judged as
+though the eye were stationary.
+
+A somewhat similar illusion as to direction occurs in auditory
+perception. The sense of direction by the ear is known to be due in part
+to the action of the auricle, or projecting part of the ear. This
+collects the air-waves, and so adds to the intensity of the sounds,
+especially those coming from in front, and thus assists in the
+estimation of direction. This being so, if an artificial auricle is
+placed in front of the ears; if, for example, the two hands are each
+bent into a sort of auricle, and placed in front of the ears, the back
+of the hand being in front, the sense of direction (as well as of
+distance) is confused. Thus, sounds really travelling from a point in
+front of the head will appear to come from behind it.
+
+Again, the perception of the unity of an object is liable to be
+falsified by the introduction of exceptional circumstances into the
+sense-organ. This is illustrated in the well-known experiment of
+crossing two fingers, say the third and fourth, and placing a marble or
+other small round object between them. Under ordinary circumstances, the
+two lateral surfaces (that is, the outer surfaces of the two fingers)
+now pressed by the marble, can only be acted on simultaneously by _two_
+objects having convex surfaces. Consequently, we cannot help feeling the
+presence of two objects in this exceptional instance. The illusion is
+analogous to that of the stereoscope, to be spoken of presently.
+
+
+_Exceptional External Arrangements._
+
+Passing now to those cases where the exceptional circumstance is
+altogether exterior to the organ, we find a familiar example in the
+illusions connected with the action of well-known physical forces, as
+the refraction of light, and the reflection of light and sound. A stick
+half-immersed in water always _looks_ broken, however well we may know
+that the appearance is due to the bending of the rays of light.
+Similarly, an echo always sounds as though it came from some object in
+the direction in which the air-waves finally travel to the ear, though
+we are perfectly sure that these undulations have taken a circuitous
+course. It is hardly necessary to remind the reader that the deeply
+organized tendency to mistake the direction of the visible or audible
+object in these cases has from remote ages been made use of as a means
+of popular delusion. Thus, we are told by Sir D. Brewster, in his
+entertaining _Letters on Natural Magic_ (letter iv.), that the concave
+mirror was probably used as the instrument for bringing the gods before
+the people. The throwing of the images formed by such mirrors upon smoke
+or against fire, so as to make them more distinct, seems to have been a
+favourite device in the ancient art of necromancy.
+
+Closely connected with these illusions of direction with respect to
+resting objects, are those into which we are apt to fall respecting the
+movements of objects. What looks like the movement of something across
+the field of vision is made known to us either by the feeling of the
+ocular muscles, if the eye follows the object, or through the sequence
+of locally distinct retinal impressions, if the eye is stationary. Now,
+either of these effects may result, not only from the actual movement of
+the object in a particular direction, but from our own movement in an
+opposite direction; or, again, from our both moving in the first
+direction, the object more rapidly than ourselves; or, finally, from our
+both moving in an opposite direction to this, ourselves more rapidly
+than the object. There is thus always a variety of conceivable
+explanations, and the action of past experience and association shows
+itself very plainly in the determination of the direction of
+interpretation. Thus, it is our instinctive tendency to take apparent
+movement for real movement, except when the fact of our own movement is
+clearly present to consciousness, as when we are walking, or when we are
+sitting behind a horse whose movement we see. And so when the sense of
+our own movement becomes indistinct, as in a railway carriage, we
+naturally drift into the illusion that objects, such as trees, telegraph
+posts, and so on, are moving, when they are perfectly still. Under the
+same circumstances, we are apt to suppose that a train which is just
+shooting ahead of us is moving slowly.
+
+Similar uncertainties arise with respect to the relative movement of two
+objects, the eye being supposed to be fixed in space. When two objects
+seem to pass one another, it may be that they are both moving in
+contrary directions, or that one only is moving, or finally, that both
+are moving in the same direction, the one faster than the other.
+Experience and habit here again suggest the interpretation which is most
+easy, and not unfrequently produce illusion. Thus, when we watch clouds
+scudding over the face of the moon, the latter seems moving rather than
+the former, and the illusion only disappears when we fix the eye on the
+moon and recognize that it is really stationary. The probable reason of
+this is, as Wundt suggests, that experience has made it far easier for
+us to think of small objects like the moon moving rapidly, than of large
+masses like the clouds.[36]
+
+The perception of distance, still more than that of direction, is liable
+to be illusory. Indeed, the visual recognition of distance, together
+with that of solidity, has been the great region for the study of "the
+deceptions of the senses." Without treating the subject fully here, I
+shall try to describe briefly the nature and source of these
+illusions.[37]
+
+Confining ourselves first of all to near objects, we know that the
+smaller differences of distance in these cases are, if the eyes are at
+rest, perceived by means of the dissimilar pictures projected on the two
+retinas; or if they move, by this means, together with the muscular
+feelings that accompany different degrees of convergence of the two
+eyes. This was demonstrated by the famous experiments of Wheatstone.
+Thus, by means of the now familiar stereoscope, he was able to produce a
+perfect illusion of relief. The stereoscope may be said to introduce an
+exceptional state of things into the spectator's environment. It
+imitates, by means of two flat drawings, the dissimilar retinal pictures
+projected by a single solid receding object, and the lenses through
+which the eyes look are so constructed as to compel them to converge as
+though looking on a single object. And so powerful is the tendency to
+interpret this impression as one of solidity, that even though we are
+aware of the presence of the stereoscopic apparatus, we cannot help
+seeing the two drawings as a single solid object.
+
+In the case of more remote objects, there is no dissimilarity of the
+retinal pictures or feelings of convergence to assist the eye in
+determining distance. Here its judgment, which now becomes more of a
+process of _conscious_ inference, is determined by a number of
+circumstances which, through experience and association, have become the
+signs of differences of depth in space. Among these are the degree of
+indistinctness of the impression, the apparent or retinal magnitude (if
+the object is a familiar one), the relations of linear perspective, as
+the interruption of the outline of far objects by that of near objects,
+and so on. In a process so complicated there is clearly ample room for
+error, and wrong estimates of distance whenever unusual circumstances
+are present are familiar to all. Thus, the inexperienced English
+tourist, when in the clear atmosphere of Switzerland, where the
+impressions from distant objects are more distinct than at home,
+naturally falls into the illusion that the mountains are much nearer
+than they are, and so fails to realize their true altitude.
+
+_Illusions of Art._
+
+The imitation of solidity and depth by art is a curious and interesting
+illustration of the mode of production of illusion. Here we are not, of
+course, concerned with the question how far illusion is desirable in
+art, but only with its capabilities of illusory presentment; which
+capabilities, it may be added, have been fully illustrated in the
+history of art. The full treatment of this subject would form a chapter
+in itself; here I can only touch on its main features.
+
+Pictorial art working on a flat surface cannot, it is plain, imitate the
+stereoscope, and produce a perfect sense of solidity. Yet it manages to
+produce a pretty strong illusion. It illustrates in a striking manner
+the ease with which the eye conceives relations of depth or relief and
+solidity. If, for example, on a carpet, wall-paper, or dress, bright
+lines are laid on a dark colour as ground, we easily imagine that they
+are advancing. The reason of this seems to be that in our daily
+experience advancing surfaces catch and reflect the light, whereas
+retiring surfaces are in shadow.[38]
+
+The same principle is illustrated in one of the means used by the artist
+to produce a strong sense of relief, namely, the cast shadow. A circle
+drawn with chalk with a powerful cast shadow on one side will, without
+any shading or modelling of the form, appear to stand out from the
+paper, thus:
+
+[Illustration: FIG. 1.]
+
+The reason is that the presence of such a shadow so forcibly suggests to
+the mind that the object is a prominent one intervening between the
+light and the shaded surface.[39]
+
+Even without differences of light and shade, by a mere arrangement of
+lines, we may produce a powerful sense of relief or solidity. A striking
+example of this is the way in which two intersecting lines sometimes
+appear to recede from the eye, as the lines _a a'_, _b b'_, in the next
+drawing, which seem to belong to a regular pattern on the ground, at
+which the eye is looking from above and obliquely.
+
+[Illustration: FIG. 2.]
+
+Again, the correct delineation of the projection of a regular
+geometrical figure, as a cube, suffices to give the eye a sense of
+relief. This effect is found to be the more striking in proportion to
+the familiarity of the form. The following drawing of a long box-shaped
+solid at once seems to stand out to the eye.
+
+[Illustration: FIG. 3.]
+
+This habitual interpretation of the flat in art as answering to objects
+in relief, or having depth, can only be understood when it is remembered
+that our daily experience gives us myriads of instances in which the
+effect of such flat representations answers to solid receding forms.
+That is to say, in the case of all distant objects, in the perception of
+which the dissimilarity of the retinal pictures and the feeling of
+convergence take no part, we have to interpret solidity, and relations
+of nearer and further, by such signs as linear perspective and cast
+shadow. On the other hand, it is only in the artificial life of indoors,
+on our picture-covered walls, that we experience such effects without
+discovering corresponding realities. Hence a deeply organized habit of
+taking these impressions as answering to the solid and not to the flat.
+If our experience had been quite different; if, for example, we had
+been brought up in an empty room, amid painted walls, and had been
+excluded from the sight of the world of receding objects outside, we
+might easily have formed an exactly opposite habit of taking the actual
+mountains, trees, etc., of the distant scene to be pictures laid on a
+flat surface.
+
+[Illustration: FIG. 4.]
+
+It follows from this that, with respect to the distant parts of a scene,
+pictorial art possesses the means of perfect imitation; and here we see
+that a complete illusory effect is obtainable. I need but to refer to
+the well-known devices of linear and aerial perspective, by which this
+result is secured.[40] The value of these means of producing illusion at
+the command of the painter, may be illustrated by the following fact,
+which I borrow from Helmholtz. If you place two pieces of cardboard
+which correspond to portions of one form at the sides and in front of a
+third piece, in the way represented above, so as just to allow the eye
+to follow the contour of this last, and then look at this arrangement
+from a point at some little distance with one eye, you easily suppose
+that it stands in front of the side pieces. The explanation of the
+illusion is that this particular arrangement powerfully suggests that
+the outline of the whole figure, of which the two side pieces are parts,
+is broken by an intervening object. Owing to the force of these and
+other suggestions, it is easy for the spectator, when attending to the
+background of a landscape painting, to give himself up for a moment to
+the pleasant delusion that he is looking at an actual receding scene.
+
+In connection with pictorial delusion, I may refer to the well-known
+fact, that the eye in a portrait seems to follow the spectator, or that
+a gun, with its muzzle pointing straight outwards, appears to turn as
+the spectator moves.[41] These tricks of art have puzzled many people,
+yet their effect is easily understood, and has been very clearly
+explained by Sir D. Brewster, in the work already referred to (letter
+v.). They depend on the fact that a painting, being a flat projection
+only and not a solid, continues to present the front view of an object
+which it represents wherever the spectator happens to stand. Were the
+eye in the portrait a real eye, a side movement of the spectator would,
+it is evident, cause him to see less of the pupil and more of the side
+of the eyeball, and he would only continue to see the full pupil when
+the eye followed him. We regard the eye in the picture as a real eye
+having relief, and judge accordingly.
+
+We may fall into similar illusions respecting distance in auditory
+perception. A change of wind, an unusual stillness in the air, is quite
+sufficient to produce the sense that sounding objects are nearer than
+they actually are. The art of the ventriloquist manifestly aims at
+producing this kind of illusion. By imitating the dull effect of a
+distant voice, he is able to excite in the minds of his audience a
+powerful conviction that the sounds proceed from a distant point. There
+is little doubt that ventriloquism has played a conspicuous part in the
+arts of divination and magic.
+
+
+_Misconception of Local Arrangement._
+
+Let us now pass to a class of illusions closely related to those having
+to do with distance, but involving some special kind of circumstance
+which powerfully suggests a particular arrangement in space. One of the
+most striking examples of these is the erroneous localization of a
+quality in space, that is to say, the reference of it to an object
+nearer, or further off than the right one. Thus, when we look through a
+piece of yellow glass at a dull, wintry landscape, we are disposed to
+imagine that we are looking at a sunny scene of preternatural warmth. A
+moment's reflection would tell us that the yellow tint, with which the
+objects appear to be suffused, comes from the presence of the glass;
+yet, in spite of this, the illusion persists with a curious force. The
+explanation is, of course, that the circumstances are exceptional, that
+in a vast majority of cases the impression of colour belongs to the
+object and not to an intervening medium,[42] and that consequently we
+tend to ignore the glass, and to refer the colour to the objects
+themselves.
+
+When, however, the fact of the existence of a coloured medium is
+distinctly present to the mind, we easily learn to allow for this, and
+to recognize one coloured surface correctly through a recognized medium.
+Thus, we appear to ourselves to see the reflected images of the wall,
+etc., of a room, in a bright mahogany table, not suffused with a reddish
+yellow tint, as they actually are--and may be seen to be by the simple
+device of looking at a small bit of the image through a tube, but in
+their ordinary colour. We may be said to fall into illusion here in so
+far as we overlook the exact quality of the impression actually made on
+the eye. This point will be touched on presently. Here I am concerned to
+show that this habit of allowing for the coloured medium may, in its
+turn, occasionally lead to plain and palpable illusion.
+
+The most striking example of this error is to be met with among the
+curious phenomena of colour-contrast already referred to. In many of
+these cases the appearance of the contrasting colour is, as I have
+observed, due to a temporary modification of the nervous substance. Yet
+it is found that this organic factor does not wholly account for the
+phenomena. For example, Meyer made the following experiment. He covered
+a piece of green paper by a sheet of thin transparent white paper. The
+colour of this double surface was, of course, a pale green. He then
+introduced a scrap of grey paper between the two sheets, and found that,
+instead of looking whitish as it really was, it looked rose-red.
+Whatever the colour of the under sheet the grey scrap took the
+complementary hue. If, however, the piece of grey paper is put outside
+the thin sheet, it looks grey; and what is most remarkable is that when
+a second piece is put outside, the scrap inside no longer wears the
+complementary hue.
+
+There is here evidently something more than a change of organic
+conditions; there is an action of experience and suggestion. The reason
+of our seeing the scrap rose-red in one case and neutral grey in
+another, is that in the first instance we vividly represent to ourselves
+that we are looking at it through a greenish veil (which is, of course,
+a part of the illusion); for rose-red seen through a greenish medium
+would, as a matter of fact, be light grey, as this scrap is. Even if we
+allow that there always exists after an impression of colour a temporary
+organic disposition to see the complementary hue, this does not suffice
+as an explanation of these cases; we have to conclude further that
+imagination, led by the usual run of our experience, is here a
+co-operant factor, and helps to determine whether the complementary tint
+shall be seen or not.
+
+
+_Misinterpretation of Form._
+
+More complex and circumscribed associations take part in those errors
+which we occasionally commit respecting the particular form of objects.
+This has already been touched on in dealing with artistic illusion. The
+disposition of the eye to attribute solidity to a flat drawing is the
+more powerful in proportion to the familiarity of the form. Thus, an
+outline drawing of a building is apt to stand out with special force.
+
+Another curious illustration of this is the phenomenon known as the
+conversion of the concave mould or matrix of a medal into the
+corresponding convex relief. If, says Helmholtz, the mould of a medal be
+illuminated by a light falling obliquely so as to produce strong
+shadows, and if we regard this with one eye, we easily fall into the
+illusion that it is the original raised design, illuminated from _the
+opposite side_. As a matter of fact, the visual impression produced by a
+concave form with the light falling on one side, very closely resembles
+that produced by a corresponding convex form with the light falling on
+the other side. At the same time, it is found that the opposite mode of
+conversion, that is to say, the transformation of the raised into the
+depressed form, though occurring occasionally, is much less frequent.
+Now, it may be asked, why should we tend to transform the concave into
+the convex, rather than the convex into the concave? The reader may
+easily anticipate the answer from what has been said about the deeply
+fixed tendency of the eye to solidify a plane surface. We are rendered
+much more familiar, both by nature and by art, with raised (_cameo_)
+design than with depressed design (_intaglio_), and we instinctively
+interpret the less familiar form by the more familiar. This explanation
+appears to be borne out by the fact emphasized by Schroeder that the
+illusion is much more powerful if the design is that of some well-known
+object, as the human head or figure, or an animal form, or leaves.[43]
+
+Another illustration of this kind of illusion recently occurred in my
+own experience. Nearly opposite to my window came a narrow space between
+two detached houses. This was, of course, darker than the front of the
+houses, and the receding parallel lines of the bricks appeared to cross
+this marrow vertical shaft obliquely. I could never look at this without
+seeing it as a convex column, round which the parallel lines wound
+obliquely. Others saw it as I did, though not always with the same
+overpowering effect. I can only account for this illusion by help of the
+general tendency of the eye to solidify impressions drawn from the flat,
+together with the effect of special types of experience, more
+particularly the perception of cylindrical forms in trees, columns, etc.
+
+It may be added that a somewhat similar illustration of the action of
+special types of experience on the perception of individual form may be
+found in the region of hearing. The powerful disposition to take the
+finely graduated cadences of sound produced by the wind for the
+utterances of a Iranian voice, is due to the fact that this particular
+form and arrangement of sound has deeply impressed itself on our minds,
+in connection with numberless utterances of human feeling.
+
+_Illusions of Recognition._
+
+As a last illustration of comparatively passive illusions, I may refer
+to the errors which we occasionally commit in recognizing objects. As I
+have already observed, the process of full and clear recognition,
+specific and individual, involves a classing of a number of distinct
+aspects of the object, such as colour, form, etc. Accordingly, when in a
+perfectly calm state of mind we fall into illusion with respect to any
+object plainly visible, it must be through some accidental resemblance
+between the object and the other object or class of objects with which
+we identify it. In the case of individual identification such illusions
+are, of course, comparatively rare, since here there are involved so
+many characteristic differences. On the other hand, in the case of
+specific recognition there is ample room for error, especially in those
+kinds of more subtle recognition to which I have already referred. To
+"recognize" a person as a Frenchman or a military man, for example, is
+often an erroneous process. Logicians have included this kind of error
+under what they call "fallacies of observation."
+
+Errors of recognition, both specific and individual, are, of course,
+more easy in the case of distant objects or objects otherwise
+indistinctly seen. It is noticeable in these cases that, even when
+perfectly cool and free from emotional excitement, we tend to interpret
+such indistinct impressions according to certain favourite types of
+experience, as the human face and figure. Our interpretative imagination
+easily sees traces of the human form in cloud, rock, or tree-stump.
+
+Again, even when there is no error of recognition, in the sense of
+confusing one object with other objects, there may be partial illusion.
+I have remarked that the process of recognizing an object commonly
+involves an overlooking of points of diversity in the object, or aspect
+of the object, now present. And sometimes this inattention to what is
+actually present includes an error as to the actual visual sensation of
+the moment. Thus, for example, when I look at a sheet of white paper in
+a feebly lit room, I seem to see its whiteness. If, however, I bring it
+near the window, and let the sun fall on a part of it, I at once
+recognize that what I have been seeing is not white, but a decided grey.
+Similarly, when I look at a brick viaduct a mile or two off, I appear to
+myself to recognize its redness. In fact, however, the impression of
+colour which I receive from the object is not that of brick-red at all,
+but a much less decided tint; which I may easily prove by bending my
+head downwards and letting the scene image itself on the retina in an
+unusual way, in which case the recognition of the object as a viaduct
+being less distinct, I am better able to attend to the exact shade of
+the colour.
+
+Nowhere is this inattention to the sensation of the moment exhibited in
+so striking a manner as in pictorial art. A picture of Meissonier may
+give the eye a representation of a scene in which the objects, as the
+human figures and horses, have a distinctness that belongs to near
+objects, but an apparent magnitude that belongs to distant objects. So
+again, it is found that the degree of luminosity or brightness of a
+pictorial representation differs in general enormously from that of the
+actual objects. Thus, according to the calculations of Helmholtz,[44] a
+picture representing a Bedouin's white raiment in blinding sunshine,
+will, when seen in a fairly lit gallery, have a degree of luminosity
+reaching only to about one-thirtieth of that of the actual object. On
+the other hand, a painting representing marble ruins illuminated by
+moonlight, will, under the same conditions of illumination, have a
+luminosity amounting to as much as from ten to twenty thousand times
+that of the object. Yet the spectator does not notice these stupendous
+discrepancies. The representation, in spite of its vast difference, at
+once carries the mind on to the actuality, and the spectator may even
+appear to himself, in moments of complete absorption, to be looking at
+the actual scene.
+
+The truly startling part of these illusions is, that the direct result
+of sensory stimulation appears to be actually displaced by a mental
+image. Thus, in the case of Meyer's experiment, of looking at the
+distant viaduct, and of recognizing an artistic representation,
+imagination seems in a measure to take the place of sensation, or to
+blind the mind to what is actually before it.
+
+The mystery of the process, however, greatly disappears when it is
+remembered that what we call a conscious "sensation" is really
+compounded of a result of sensory stimulation and a result of central
+reaction, of a purely passive impression and the mental activity
+involved in attending to this and classing it.[45] This being so, a
+sensation may be modified by anything exceptional in the mode of central
+reaction of the moment. Now, in all the cases just considered, we have
+one common feature, a powerful suggestion of the presence of a
+particular object or local arrangement. This suggestion, taking the form
+of a vivid mental image, dominates and overpowers the passive
+impression. Thus, in Meyer's experiment, the mind is possessed by the
+supposition that we are looking at the grey spot through a greenish
+medium. So in the case of the distant viaduct, we are under the mastery
+of the idea that what we see in the distance is a red brick structure.
+Once more, in the instance of looking at the picture, the spectator's
+imagination is enchained by the vivid representation of the object for
+which the picture stands, as the marble ruins in the moonlight or the
+Bedouin in the desert.
+
+It may be well to add that this mental uncertainty as to the exact
+nature of a present impression is necessitated by the very conditions of
+accurate perception. If, as I have said, all recognition takes place by
+overlooking points of diversity, the mind must, in course of time,
+acquire a habit of not attending to the exact quality of
+sense-impressions in all cases where the interpretation seems plain and
+obvious. Or, to use Helmholtz's words, our sensations are, in a general
+way, of interest to us only as signs of things, and if we are sure of
+the thing, we readily overlook the precise nature of the impression. In
+short, we get into the way of attending only to what is essential,
+constant, and characteristic in objects, and disregarding what is
+variable and accidental.[46] Thus, we attend, in the first place, to the
+form of objects, the most constant and characteristic element of all,
+being comparatively inattentive to colour, which varies with distance,
+atmospheric changes, and mode of illumination. So we attend to the
+relative magnitude of objects rather than to the absolute, and to the
+relative intensities of light and shade rather than to the absolute; for
+in so doing we are noting what is constant for all distances and modes
+of illumination, and overlooking what is variable. And the success of
+pictorial art depends on the observance of this law of perception.
+
+These remarks at once point out the limits of these illusions. In normal
+circumstances, an act of imagination, however vivid, cannot create the
+semblance of a sensation which is altogether absent; it can only
+slightly modify the actual impression by interfering with that process
+of comparison and classification which enters into all definite
+determination of sensational quality.
+
+Another great fact that has come to light in the investigation of these
+illusions is that oft-recurring and familiar types of experience leave
+permanent dispositions in the mind. As I said when describing the
+process of perception, what has been frequently perceived is perceived
+more and more readily. It follows from this that the mind will be
+habitually disposed to form the corresponding mental images, and to
+interpret impressions by help of these. The range of artistic suggestion
+depends on this. A clever draughtsman can indicate a face by a few rough
+touches, and this is due to the fact that the spectator's mind is so
+familiarized, through recurring experience and special interest, with
+the object, that it is ready to construct the requisite mental image at
+the slightest external suggestion. And hence the risk of hasty and
+illusory interpretation.
+
+These observations naturally conduct us to the consideration of the
+second great group of sense-illusions, which I have marked off as active
+illusions, where the action of a pre-existing intellectual disposition
+becomes much more clearly marked, and assumes the form of a free
+imaginative transformation of reality.
+
+
+
+
+CHAPTER VI.
+
+ILLUSIONS OF PERCEPTION--_continued_.
+
+B. _Active Illusions._
+
+
+When giving an account of the mechanism of perception, I spoke of an
+independent action of the imagination which tends to anticipate the
+process of suggestion from without. Thus, when expecting a particular
+friend, I recognize his form much more readily than when my mind has not
+been preoccupied with his image.
+
+A little consideration will show that this process must be highly
+favourable to illusion. To begin with, even if the preperception be
+correct, that is to say, if it answer to the perception, the mere fact
+of vivid expectation will affect the exact moment of the completed act
+of perception. And recent experiment shows that in certain cases such a
+previous activity of expectant attention may even lead to the illusory
+belief that the perception takes place before it actually does.[47]
+
+A more palpable source of error resides in the risk of the formation of
+an inappropriate preperception. If a wrong mental image happens to have
+been formed and vividly entertained, and if the actual impression fits
+in to a certain extent with this independently formed preperception, we
+may have a fusion of the two which exactly simulates the form of a
+complete percept. Thus, for example, in the case just supposed, if
+another person, bearing some resemblance to our expected friend, chances
+to come into view, we may probably stumble into the error of taking one
+person for another.
+
+On the physical side, we may, agreeably to the hypothesis mentioned
+above, express this result by saying that, owing to a partial identity
+in the nervous processes involved in the anticipatory image and the
+impression, the two tend to run one into the other, constituting one
+continuous process.
+
+There are different ways in which this independent activity of the
+imagination may falsify our perceptions. Thus, we may voluntarily choose
+to entertain a certain image for the moment, and to look at the
+impression in a particular way, and within certain limits such
+capricious selection of an interpretation is effectual in giving a
+special significance to an impression. Or the process of independent
+preperception may go on apart from our volitions, and perhaps in spite
+of these, in which case the illusion has something of the irresistible
+necessity of a passive illusion. Let us consider separately each mode
+of production.
+
+
+_Voluntary Selection of Interpretation._
+
+The action of a capricious exercise of the imagination in relation to an
+impression is illustrated in those cases where experience and suggestion
+offer to the interpreting mind an uncertain sound, that is to say, where
+the present sense-signs are ambiguous. Here we obviously have a choice
+of interpretation. And it is found that, in these cases, what we see
+depends very much on what we wish to see. The interpretation adopted is
+still, in a sense, the result of suggestion, but of one particular
+suggestion which the fancy of the moment determines. Or, to put it
+another way, the caprice of the moment causes the attention to focus
+itself in a particular manner, to direct itself specially to certain
+aspects and relations of objects.
+
+The eye's interpretation of movement, already referred to, obviously
+offers a wide field for this play of selective imagination. When looking
+out of the window of a railway carriage, I can at will picture to my
+mind the trees and telegraph posts as moving objects. Sometimes the true
+interpretation is so uncertain that the least inclination to view the
+phenomenon in one way determines the result. This is illustrated in a
+curious observation of Sinsteden. One evening, on approaching a windmill
+obliquely from one side, which under these circumstances he saw only as
+a dark silhouette against a bright sky, he noticed that the sails
+appeared to go, now in one direction, now in another, according as he
+imagined himself looking at the front or at the back of the
+windmill.[48]
+
+In the interpretation of geometrical drawings, as those of crystals,
+there is, as I have observed, a general tendency to view the flat
+delineation as answering to a raised object, or a body in relief,
+according to the common run of our experience. Yet there are cases where
+experience is less decided, and where, consequently, we may regard any
+particular line as advancing or receding. And it is found that when we
+vividly imagine that the drawing is that of a convex or concave surface,
+we see it to be so, with all the force of a complete perception. The
+least disposition to see it in the other way will suffice to reverse the
+interpretation. Thus, in the following drawing, the reader can easily
+see at will something answering to a truncated pyramid, or to the
+interior of a cooking vessel.
+
+[Illustration: FIG. 5.]
+
+Similarly, in the accompanying figure of a transparent solid, I can at
+will select either of the two surfaces which approximately face the eye
+and regard it as the nearer, the other appearing as the hinder surface
+looked at through the body.
+
+[Illustration: FIG. 6.]
+
+Again, in the next drawing, taken from Schroeder, one may, by an effort
+of will, see the diagonal step-like pattern, either as the view from
+above of the edge of an advancing piece of wall at _a_, or as the view
+from below of the edge of an advancing (overhanging) piece of wall at
+_b_.
+
+[Illustration: FIG. 7.]
+
+These last drawings are not in true perspective on either of the
+suppositions adopted, wherefore the choice is easier. But even when an
+outline form is in perspective, a strenuous effort of imagination may
+suffice to bring about a conversion of the appearance. Thus, if the
+reader will look at the drawing of the box-like solid (Fig. 3, p. 79),
+he will find that, after a trial or two, he succeeds in seeing it as a
+_concave_ figure representing the coyer and two sides of a box as looked
+at from within.[49]
+
+Many of my readers, probably, share in my power of variously
+interpreting the relative position of bands or stripes on fabrics such
+as wall-papers, according to wish. I find that it is possible to view
+now this stripe or set of stripes as standing out in relief upon the
+others as a ground, now these others as advancing out of the first as a
+background. The difficulty of selecting either interpretation at will
+becomes greater, of course, in those cases where there is a powerful
+suggestion of some particular local arrangement, as, for example, the
+case of patterns much brighter than the ground, and especially of such
+as represent known objects, as flowers. Yet even here a strong effort of
+imagination will often suffice to bring about a conversion of the first
+appearance.
+
+A somewhat similar choice of interpretation offers itself in looking at
+elaborate decorative patterns. When we strongly imagine any number of
+details to be elements of one figure, they seem to become so; and a
+given detail positively appears to alter in character according as it is
+viewed as an element of a more or less complex figure.
+
+These examples show what force belongs to a vivid preconception, if this
+happens to fit only very roughly the impression of the moment, that is
+to say, if the interpretative image is one of the possible suggestions
+of the impression. The play of imagination takes a wider range in those
+cases where the impression is very indefinite in character, easily
+allowing of a considerable variety of imaginative interpretation.
+
+I referred at the beginning of this account of sense-illusions to the
+readiness with which the mind deceives itself with respect to the nature
+and causes of the vague sensations which usually form the dim background
+of our mental life. A person of lively imagination, by trying to view
+these in a particular way, and by selectively attending to those aspects
+of the sensation which answer to the caprice of the moment, may give a
+variety of interpretations to one and the same set of sensations. For
+example, it is very easy to get confused with respect to those tactual
+and motor feelings which inform us of the position of our bodily
+members. And so, when lying in bed, and attending to the sensations
+connected with the legs, we may easily delude ourselves into supposing
+that these members are arranged in a most eccentric fashion. Similarly,
+by giving special heed to the sensations arising in connection with the
+condition of the skin at any part, we may amuse ourselves with the
+strangest fancies as to what is going on in these regions.
+
+Again, when any object of visual perception is indistinct or indefinite
+in form, there is plainly an opening for this capricious play of fancy
+in transforming the actual. This is illustrated in the well-known
+pastime of discovering familiar forms, such as those of the human head
+and animals, in distant rocks and clouds, and of seeing pictures in the
+fire, and so on. The indistinct and indefinite shapes of the masses of
+rock, cloud, or glowing coal, offer an excellent field for creative
+fancy, and a person of lively imagination will discover endless forms in
+what, to an unimaginative eye, is a formless waste. Johannes Müller
+relates that, when a child, he used to spend hours in discovering the
+outlines of forms in the partly blackened and cracked stucco of the
+house that stood opposite to his own.[50] Here it is plain that, while
+experience and association are not wholly absent, but place certain wide
+limits on this process of castle-building, the spontaneous activity of
+the percipient mind is the great determining force.
+
+So much as to the influence of a perfectly unfettered voluntary
+attention on the determination of the stage of preperception, and,
+through this, of the resulting interpretation. Let us now pass to cases
+in which this direction of preperception follows not the caprice of the
+moment, but the leading of some fixed predisposition in the
+interpreter's mind. In these cases attention is no longer free, but
+fettered, only it is now fettered rather from within than from without;
+that is to say, the dominating preperception is much more the result of
+an independent bent of the imagination than of some suggestion forced on
+the mind by the actual impression of the moment.
+
+_Involuntary Mental Preadjustment._
+
+
+If we glance back at the examples of capricious selection just noticed,
+we shall see that they are really limited not only by the character of
+the impression of the time, but also by the mental habits of the
+spectator. That is to say, we find that his fancy runs in certain
+definite directions, and takes certain habitual forms. It has already
+been observed that the percipient mind has very different attitudes with
+respect to various kinds of impression. Towards some it holds itself at
+a distance, while towards others it at once bears itself familiarly; the
+former are such as answer to its previous habit and bent of imagination,
+the latter such as do not so answer.
+
+This bent of the interpretative imagination assumes, as we have already
+seen, two forms, that of a comparatively permanent disposition, and that
+of a temporary state of expectation or mental preparedness. Illusion may
+arise in connection with either of these forms. Let us illustrate both
+varieties, beginning with those which are due to a lasting mental
+disposition.
+
+It is impossible here to specify all the causes of illusion residing in
+organized tendencies of the mind. The whole past mental life, with its
+particular shade of experience, its ruling emotions, and its habitual
+direction of fancy, serves to give a particular colour to new
+impressions, and so to favour illusion. There is a "personal equation"
+in perception as in belief--an amount of erroneous deviation from the
+common average view of external things, which is the outcome of
+individual temperament and habits of mind. Thus, a naturally timid man
+will be in general disposed to see ugly and fearful objects where a
+perfectly unbiased mind perceives nothing of the kind; and the forms
+which these objects of dread will assume are determined by the character
+of his past experience, and by the customary direction of his
+imagination.
+
+In perfectly healthy states of mind this influence of temperament and
+mental habit on the perception of external objects is, of course, very
+limited; it shows itself more distinctly, as we shall see, in modifying
+the estimate of things in relation to the æsthetic and other feelings.
+This applies to the mythical poetical way of looking at nature--a part
+of our subject to which we shall have to return later on.
+
+Passing now from the effect of such permanent dispositions, let us look
+at the more striking results of temporary expectancy of mind.
+
+When touching on the influence of such a temporary mental attitude in
+the process of correct perception, I remarked that this readiness of
+mind might assume an indefinite or a definite form. We will examine the
+effect of each kind in the production of illusion.
+
+
+_Action of Sub-Expectation._
+
+First of all, then, our minds may at the particular moment be disposed
+to entertain any one of a vaguely circumscribed group of images. Thus,
+to return to the example already referred to, when in Italy, we are in a
+state of readiness to frame any of the images that we have learnt to
+associate with this country. We may not be distinctly anticipating any
+one kind of object, but are nevertheless in a condition of
+_sub-expectation_ with reference to a large number of objects.
+Accordingly, when an impression occurs which answers only very roughly
+to one of the associated images, there is a tendency to superimpose the
+image on the impression. In this way illusion arises. Thus, a man, when
+strolling in a cathedral, will be apt to take any kind of faint hollow
+sound for the soft tones of an organ.
+
+The disposition to anticipate fact and reality in this way will be all
+the stronger if, as usually happens, the mental images thus lying ready
+for use have an emotional colouring. Emotion is the great disturber of
+all intellectual operations. It effects marvellous things, as we shall
+presently see, in the region of illusory belief, and its influence is
+very marked in the seemingly cooler region of external perception. The
+effect of any emotional excitement appears to be to give a preternatural
+vividness and persistence to the ideas answering to it, that is to say,
+the ideas which are its excitants, or which are otherwise associated
+with it. Owing to this circumstance, when the mind is under the
+temporary sway of any feeling, as, for example, fear, there will be a
+special readiness to interpret objects by help of images congruent with
+the emotion. Thus, a man under the control of fear will be ready to see
+any kind of fear-inspiring object whenever there is any resemblance to
+such in the things actually present to his vision. The state of awe
+which the surrounding circumstances of a spiritualist _séance_ inspires
+produces a general readiness of mind to perceive what is strange,
+mysterious, and apparently miraculous.
+
+It is worth noting, perhaps, that those delightful half-illusions which
+imitative art seeks to produce are greatly favoured by such a temporary
+attitude of the interpreting imagination. In the theatre, for example,
+we are prepared for realizing the semblance of life that is to be
+unfolded before us. We come knowing that what is to be performed aims at
+representing a real action or actual series of events. We not improbably
+work ourselves into a slightly excited state in anticipation of such a
+representation. More than this, as the play progresses, the realization
+of what has gone before produces a strong disposition to believe in the
+reality of what is to follow. And this effect is proportionate to the
+degree of coherence and continuity in the action. In this way, there is
+a cumulative effect on the mind. If the action is good, the illusion, as
+every play-goer knows, is most complete towards the end.
+
+Were it not for all this mental preparation, the illusory character of
+the performance would be too patent to view, and our enjoyment would
+suffer. A man is often aware of this when coming into a theatre during
+the progress of a piece before his mind accommodates itself to the
+meaning of the play. And the same thing is recognizable in the fact that
+the frequenter of the theatre has his susceptibility to histrionic
+delusion increased by acquiring a habit of looking out for the meaning
+of the performance. Persons who first see a play, unless they be of
+exceptional imagination and have thought much about the theatre--as
+Charlotte Brontë, for instance--hardly feel the illusion at all. At
+least, this is true of the opera, where the departure from reality is
+so striking that the impression can hardly fail to be a ludicrous one,
+till the habit of taking the performance for what it is intended to be
+is fully formed.[51]
+
+A similar effect of intellectual preadjustment is observable in the
+fainter degrees of illusion produced by pictorial art. Here the
+undeceiving circumstances, the flat surface, the surroundings, and so
+on, would sometimes be quite sufficient to prevent the least degree of
+illusion, were it not that the spectator comes prepared to see a
+representation of some real object. This is our state of mind when we
+enter a picture gallery or approach what we recognize as a picture on
+the wall of a room. A savage would not "realize" a slight sketch as soon
+as one accustomed to pictorial representation, and ready to perform the
+required interpretative act.[52]
+
+So much as to the effect of an indefinite state of sub-expectation in
+misleading our perceptions. Let us now glance at the results of definite
+preimagination, including what are generally known as expectations.
+
+_Effects of Vivid Expectation._
+
+
+Such expectations may grow out of some present objective facts, which
+serve as signs of the expected event; or they may arise by way of verbal
+suggestion; or, finally, they may be due to internal spontaneous
+imagination.
+
+In the first place, then, the expectations may grow out of previous
+perceptions, while, nevertheless, the direction of the expectation may
+be a wrong one. Here the interpreting imagination is, in a large sense,
+under the control of external suggestion, though, with respect to the
+particular impression that is misconstrued, it may be regarded as acting
+independently and spontaneously.
+
+Illustrations of this effect in producing illusion will easily occur to
+the reader. If I happen to have heard that a particular person has been
+a soldier or clergyman, I tend to see the marks of the class in this
+person, and sometimes find that this process of recognition is
+altogether illusory. Again, let us suppose that a person is expecting a
+friend by a particular train. A passenger steps out of the train bearing
+a superficial resemblance to his friend; in consequence of which he
+falls into the error of false identification.
+
+The delusions of the conjuror depend on a similar principle. The
+performer tells his audience that he is about to do a certain thing, for
+example, take a number of animals out of a small box which is incapable
+of holding them. The hearers, intent on what has been said, vividly
+represent to themselves the action described. And in this way their
+attention becomes bribed, so to speak, beforehand, and fails to notice
+the inconspicuous movements which would at once clear up the mystery.
+Similarly with respect to the illusions which overtake people at
+spiritualist _séances_. The intensity of the expectation of a particular
+kind of object excludes calm attention to what really happens, and the
+slightest impressions which answer to signs of the object anticipated
+are instantly seized by the mind and worked up into illusory
+perceptions.
+
+It is to be noted that even when the impression cannot be made to tally
+exactly with the expectation, the force of the latter often effects a
+grotesque confusion of the perception. If, for example, a man goes into
+a familiar room in the dark in order to fetch something, and for a
+moment forgets the particular door by which he has entered, his definite
+expectation of finding things in a certain order may blend with the
+order of impressions experienced, producing for the moment a most
+comical illusion as to the actual state of things.
+
+When the degree of expectation is unusually great, it may suffice to
+produce something like the counterfeit of a real sensation. This happens
+when the present circumstances are powerfully suggestive of an immediate
+event. The effect is all the more powerful, moreover, in those cases
+where the object or event expected is interesting or exciting, since
+here the mental image gains in vividness through the emotional
+excitement attending it. Thus, if I am watching a train off and know
+from all the signs that it is just about to start, I easily delude
+myself into the conviction that it has begun to start, when it is
+really still.[53] An intense degree of expectation may, in such cases,
+produce something indistinguishable from an actual sensation. This
+effect is seen in such common experiences as that the sight of food
+makes the mouth of a hungry man water; that the appearance of a surgical
+instrument produces a nascent sensation of pain; and that a threatening
+movement, giving a vivid anticipation of tickling, begets a feeling
+which closely approximates to the result of actual tickling.
+
+One or two very striking instances of such imagined sensations are given
+by Dr. Carpenter.[54] Here is one. An officer who superintended the
+exhuming of a coffin rendered necessary through a suspicion of crime,
+declared that he already experienced the odour of decomposition, though
+it was afterwards found that the coffin was empty.[55]
+
+It is, of course, often difficult to say, in such cases as these, how
+far elements of actual sensation co-operate in the production of the
+illusions. Thus, in the case just mentioned, the odour of the earth may
+have been the starting-point in the illusion. In many cases, however, an
+imaginative mind appears to be capable of transforming a vivid
+expectation into a nascent stage of sensation. Thus, a mother thinking
+of her sick child in an adjoining room, and keenly on the alert for its
+voice, will now and again fancy she really hears it when others hear
+nothing at all.
+
+
+_Transition to Hallucination._
+
+It is plain that in these cases illusion approaches to hallucination.
+Imagination, instead of waiting on sensation, usurps its place and
+imitates its appearance. Such a "subjective" sensation produced by a
+powerful expectation might, perhaps, by a stretch of language, be
+regarded as an illusion, in the narrow sense, in so far as it depends on
+the suggestive force of a complete set of external circumstances; on the
+other hand, it is clearly an hallucination in so far as it is the
+production of the semblance of an external impression without any
+external agency corresponding to this.
+
+In the class of illusory expectations just considered the immediately
+present environment still plays a part, though a much less direct part
+than that observable in the first large group of illusions. We will now
+pass to a second mode of illusory expectation, where imagination is
+still more detached from the present surroundings.
+
+A common instance of this kind of expectation is the so-called
+"intuition," or presentiment; that something is going to happen, which
+expectation has no basis in fact. It does not matter whether the
+expectation has arisen by way of another's words or by way of personal
+inclinations. A strong wish for a thing will, in an exalted state of
+mind, beget a vivid anticipation of it. This subject will be touched on
+again under the Illusions of Belief. Here I am concerned to point out
+that such presentiments are fertile sources of sense-illusion. The
+history of Church miracles, visions, and the like amply illustrates the
+effect of a vivid anticipation in falsifying the perceptions of external
+things.
+
+In persons of a lively imagination any recent occupation of the mind
+with a certain kind of mental image may suffice to beget something
+equivalent to a powerful mode of expectation. For example, we are told
+by Dr. Tuke that on one occasion a lady, whose imagination had been
+dwelling on the subject of drinking fountains, "thought she saw in a
+road a newly erected fountain, and even distinguished an inscription
+upon it, namely, 'If any man thirst, let him come unto Me, and drink.'
+She afterwards found that what she had actually seen was only a few
+scattered stones."[56] In many cases there seems to be a temporary
+preternatural activity of the imagination in certain directions, of
+which no very obvious explanation is discoverable. Thus, we sometimes
+find our minds dwelling on some absent friend, without being able to
+give any reason for this mental preoccupation. And in this way arise
+strong temporary leanings to illusory perception. It may be said,
+indeed, that all unwonted activity of the imagination, however it
+arises, has as its immediate result a temporary mode of expectation,
+definite or indefinite, which easily confuses our perceptions of
+external things.
+
+In proportion as this pre-existing imaginative impulse becomes more
+powerful, the amount of actual impression necessary to transform the
+mental image into an illusory perception becomes less; and, what is more
+important, this transformation of the internal image involves a larger
+and larger displacement of the actual impression of the moment. A man
+whose mind is at the time strongly possessed by one kind of image, will
+tend to project this outwards with hardly any regard to the actual
+external circumstances.
+
+This state of things is most completely illustrated in many of the
+grosser illusions of the insane. Thus, when a patient takes any small
+objects, as pebbles, for gold and silver, under the influence of the
+dominant idea of being a millionaire, it is obvious that external
+suggestion has very little to do with the self-deception. The confusions
+into which the patient often falls with respect to the persons before
+him show the same state of mind; for in many cases there is no
+discoverable individual resemblance between the person actually present
+and the person for whom he is taken.
+
+It is evident that when illusion reaches this stage, it is scarcely
+distinguishable from what is specially known as hallucination. As I have
+remarked in setting out, illusion and hallucination shade one into the
+other much too gradually for us to draw any sharp line of demarcation
+between them. And here we see that hallucination differs from illusion
+only in the proportion in which the causes are present. When the
+internal imaginative impulse reaches a certain strength, it becomes
+self-sufficient, or independent of any external impression.
+
+This intimate relation between the extreme form of active illusion and
+hallucination may be seen, too, by examining the physical conditions of
+each. As I have already remarked, active illusion has for its
+physiological basis a state of sub-excitation, or an exceptional
+condition of irritability in the structures engaged in the act of
+interpretative imagination. The greater the degree of this irritability,
+the less will be the force of external stimulation needed to produce the
+effect of excitation, and the more energetic will be the degree of this
+excitation. Moreover, it is plain that this increase in the strength of
+the excitation will involve an extension of the area of excitation till,
+by-and-by, the peripheral regions of the nervous system may be involved
+just as in the case of external stimulation. This accounts for the
+gradual displacement of the impression of the moment by the mental
+image. It follows that when the irritability reaches a certain degree,
+the amount of external stimulus needed may become a vanishing quantity,
+or the state of sub-excitation may of itself develop into one of full
+activity.
+
+
+_Hallucinations._
+
+I do not propose to go very fully into the description and explanation
+of hallucinations here, since they fall to a large extent under the
+category of distinctly pathological phenomena. Yet our study of
+illusions would not be complete without a glance at this part of the
+subject.
+
+Hallucination, by which I mean the projection of a mental image outwards
+when there is no external agency answering to it, assumes one of two
+fairly distinct forms: it may present itself either as a semblance of an
+external impression with the minimum amount of interpretation, or as a
+counterfeit of a completely developed percept. Thus, a visual
+hallucination may assume the aspect of a sensation of light or colour
+which we vaguely refer to a certain region of the external world, or of
+a vision of some recognizable object. All of us frequently have
+incomplete visual and auditory hallucinations of the first order,
+whereas the complete hallucinations of the second order are
+comparatively rare. The first I shall call rudimentary, the second
+developed, hallucinations.
+
+Rudimentary hallucinations may have either a peripheral or a central
+origin. They may first of all have their starting-point in those
+subjective sensations which, as we have seen, are connected with certain
+processes set up in the peripheral regions of the nervous system. Or,
+secondly, they may originate in a certain preternatural activity of the
+sensory centres, or "sensorium," in what has been called by German
+physiologists an automatic excitation of the central structures, which
+activity may probably diffuse itself downwards to the peripheral regions
+of the nerves. Baillarger would call hallucinations of the former class
+"psycho-sensorial," those of the latter class purely "psychical,"
+hallucinations.[57]
+
+It is often a matter of great difficulty to determine which part of the
+nervous system is originally concerned in these rudimentary
+hallucinations. It is probable that in normal life they are most
+frequently due to peripheral disturbance. And it seems reasonable to
+suppose that where the hallucination remains in this initial stage of a
+very incompletely interpreted visual or auditory impression, whether in
+normal or abnormal life, its real physiological source is the periphery.
+For the automatic excitation of the centres would pretty certainly issue
+in the semblance of some definite, familiar variety of sense-impression
+which, moreover, as a part of a complex state known as a percept, would
+instantly present itself as a completely formed quasi-percept. In truth,
+we may pretty safely argue that if it is the centre which is directly
+thrown into a state of activity, it will be thrown into the usual
+complex, that is to say, _perceptional_, mode of activity.
+
+Let us now turn to hallucinations properly so called, that is to say,
+completely developed quasi-percepts. These commonly assume the form of
+visual or auditory hallucinations. Like the incomplete hallucinations,
+they may have their starting-point either in some disturbance in the
+peripheral regions of the nervous system or in the automatic activity of
+the central structures: or, to use the language of Baillarger, we may
+say that they are either "psycho-sensorial" or purely "psychical." A
+subjective visual sensation, arising from certain conditions in the
+retina and connected portions of the optic nerve, may by chance resemble
+a familiar impression, and so be at once interpreted as an effect of a
+particular external object. More frequently, however, the automatic
+activity of the centres must be regarded, either in part or altogether,
+as the physiological cause of the phenomenon. This is clearly the case
+when, on the subjective side, the hallucination answers to a preceding
+energetic activity of the imagination, as in the case of the visionary
+and the monomaniac. Sometimes, however, as we have seen, the
+hallucinatory percept answers to previous prolonged acts of perception,
+leaving a kind of reverberation in the structures concerned; and in this
+case it is obviously impossible to say whether the peripheral or central
+regions (if either) have most to do with the hallucination.[58]
+
+The classifications of the causes of hallucination to be met with in the
+works of pathologists, bear out the distinction just drawn. Griesinger
+tells us (_op. cit._, pp. 94, 95) that the general causes of
+hallucination are: (1) Local disease of the organ of sense; (2) a state
+of deep exhaustion either of mind or of body; (3) morbid emotional
+states, such as fear; (4) outward calm and stillness between sleeping
+and waking; and (5) the action of certain poisons, as haschisch, opium,
+belladonna. The first cause points pretty distinctly to a peripheral
+origin, whereas the others appear to refer mainly, if not exclusively,
+to central derangements. Excessive fatigue appears to predispose the
+central structures to an abnormal kind of activity, and the same effect
+may be brought about by emotional agitation and by the action of
+poisons. The fourth case mentioned here, absence of external
+stimulation, would naturally raise the nervous structures to an
+exceptional pitch of excitability. Such a condition would, moreover,
+prove favourable to hallucination by blurring the distinction between
+mental image and actual impression.
+
+
+_Hallucinations of Normal Life._
+
+In normal life, perfect hallucinations, in the strict sense as distinct
+from illusions, are comparatively rare. Fully developed persistent
+hallucinations, as those of Nicolai, the Berlin bookseller, and of Mrs.
+A----, the lady cited by Sir D. Brewster, in his _Letters on Natural
+Magic_, point to the presence of incipient nervous disorder. In healthy
+life, on the other hand, while everybody is familiar with subjective
+sensations such as flying spots, phosphenes, ringing in the ears, few
+fall into the error of seeing or hearing distinct recognizable objects
+in the absence of all external impressions. In the lives of eminent men
+we read of such phenomena as very occasional events. Malebranche, for
+example, is said to have heard the voice of God calling him. Descartes
+says that, after a long confinement, he was followed by an invisible
+person, calling him to pursue his search for truth. Dr. Johnson narrates
+that he once heard his absent mother calling him. Byron tells us that he
+was sometimes visited by spectres. Goethe records that he once saw an
+exact counterpart of himself coming towards him. Sir Walter Scott is
+said to have seen a phantom of the dead Byron. It is possible that all
+of us are liable to momentary hallucinations at times of exceptional
+nervous exhaustion, though they are too fugitive to excite our
+attention.
+
+When not brought on by exhaustion or artificial means, the
+hallucinations of the sane have their origin in a preternatural power of
+imagination. It is well known that this power can be greatly improved by
+attention and cultivation. Goethe used to exercise himself in watching
+for ocular spectra, and could at will transform these subjective
+sensations into definite forms, such as flowers; and Johannes Müller
+found he had the same power.[59] Stories are told of portrait painters
+who could summon visual images of their sitters with a vividness equal
+to that of reality, and serving all the purposes of their art. Mr.
+Galton's interesting inquiries into the power of "visualizing" would
+appear to prove that many people can at will sport on the confines of
+the phantom world of hallucination. There is good reason to think that
+imaginative children tend to confuse mental images and percepts.[60]
+
+_The Hallucinations of Insanity._
+
+
+The hallucinations of the insane are but a fuller manifestation of
+forces that we see at work in normal life. Their characteristic is that
+they simulate the form of distinctly present objects, the existence of
+which is not instantly contradicted by the actual surroundings of the
+moment.[61] The hallucinations have their origin partly in subjective
+sensations, which are probably connected with peripheral disturbances,
+partly and principally in central derangements.[62] These include
+profound emotional changes, which affect the ruling mental tone, and
+exert a powerful influence on the course of the mental images. The
+hallucinations of insanity are due to a projection of mental images
+which have, owing to certain circumstances, gained a preternatural
+persistence and vividness. Sometimes it is the images that have been
+dwelt on with passionate longing before the disease, sometimes those
+which have grown most habitual through the mode of daily
+occupation,[63] and sometimes those connected with some incident at or
+near the time of the commencement of the disease.
+
+In mental disease, auditory hallucinations play a part no less
+conspicuous than visual.[64] Patients frequently complain of having
+their thoughts spoken to them, and it is not uncommon for them to
+imagine that they are addressed by a number of voices at the same
+time.[65]
+
+These auditory hallucinations offer a good opportunity for studying the
+gradual growth of centrally originating hallucinations. In the early
+stages of the disease, the patient partly distinguishes his
+representative from his preservative sounds. Thus, he talks of sermons
+being composed to him _in his head_. He calls these "internal voices,"
+or "voices of the soul." It is only when the disease gains ground and
+the central irritability increases that these audible thoughts become
+distinctly projected as external sounds into more or less definite
+regions of the environment. And it is exceedingly curious to notice the
+different directions which patients give to these sounds, referring them
+now to a quarter above the head, now to a region below the floor, and so
+on.[66]
+
+
+_Range of Sense-Illusions._
+
+And now let us glance back to see the path we have traversed. We set out
+with an account of perfectly normal perception, and found, even here, in
+the projection of our sensations of colour, sound, etc., into the
+environment or to the extremities of the organism, something which, from
+the point of view of physical science, easily wears the appearance of an
+ingredient of illusion.
+
+Waiving this, however, and taking the word illusion as commonly
+understood, we find that it begins when the element of imagination no
+longer answers to a present reality or external fact in any sense of
+this expression. In its lowest stages illusion closely counterfeits
+correct perception in the balance of the direct factor, sensation, and
+the indirect factor, mental reproduction or imagination. The degree of
+illusion increases in proportion as the imaginative element gains in
+force relatively to the present impression; till, in the wild illusions
+of the insane, the amount of actual impression becomes evanescent. When
+this point is reached, the act of imagination shows itself as a purely
+creative process, or an hallucination.
+
+While we may thus trace the progress of illusion towards hallucination
+by means of the gradual increase in force and extent of the imaginative,
+or indirect, as opposed to the sensuous, or direct, element in
+perception, we have found a second starting-point for this movement in
+the mechanism of sensation, involving, as it does, the occasional
+production of "subjective sensations." Such sensations constitute a
+border-land between the regions of illusion in the narrow sense, and
+hallucination. In their simplest and least developed form they may be
+regarded, at least in the case of hearing and sight, as partly
+hallucinatory; and they serve as a natural basis for the construction of
+complete hallucinations, or hallucinatory percepts.
+
+In these different ways, then, the slight, scarcely noticeable illusions
+of normal life lead up to the most startling hallucinations of abnormal
+life. From the two poles of the higher centres of attention and
+imagination on the one side, and the lower regions of nervous action
+involved in sensation on the other side, issue forces which may, under
+certain circumstances, develop into full hallucinatory percepts. Thus
+closely is healthy attached to morbid mental life. There seems to be no
+sudden break between our most sober every-day recognitions of familiar
+objects and the wildest hallucinations of the demented. As we pass from
+the former to the latter, we find that there is never any abrupt
+transition, never any addition of perfectly new elements, but only that
+the old elements go on combining in ever new proportions.
+
+The connection between the illusory side of our life and insanity may be
+seen in another way. All illusion has as its negative condition an
+interruption of the higher intellectual processes, the due control of
+our mental representations by reflection and reason. In the case of
+passive illusions, the error arises from our inability to subordinate
+the suggestion made by some feature of the present impression to the
+result of a fuller inspection of the object before us, or of a wider
+reflection on the past. In other words, our minds are dominated by the
+partial and the particular, to the exclusion of the total or the
+general. In active illusions, again, the powers of judgment and
+reflection, including those of calm perception itself, temporarily
+vacate their throne in favour of imagination. And this same suspension
+of the higher intellectual functions, the stupefaction of judgment and
+reflection made more complete and permanent, is just what characterizes
+insanity.
+
+We may, perhaps, express this point of connection between the illusions
+of normal life and insanity by help of a physiological hypothesis. If
+the nervous system has been slowly built up, during the course of human
+history, into its present complex form, it follows that those nervous
+structures and connections which have to do with the higher intellectual
+processes, or which represent the larger and more general relations of
+our experience, have been most recently evolved. Consequently, they
+would be the least deeply organized, and so the least stable; that is
+to say, the most liable to be thrown _hors de combat_. This is what
+happens temporarily in the case of the sane, when the mind is held fast
+by an illusion. And, in states of insanity, we see the process of
+nervous dissolution beginning with these same nervous structures, and so
+taking the reverse order of the process of evolution.[67] And thus, we
+may say that throughout the mental life of the most sane of us, these
+higher and more delicately balanced structures are constantly in danger
+of being reduced to that state of inefficiency, which in its full
+manifestation is mental disease.
+
+Does this way of putting the subject seem alarming? Is it an appalling
+thought that our normal mental life is thus intimately related to
+insanity, and graduates away into it by such fine transitions? A
+moment's reflection will show that the case is not so bad as it seems.
+It is well to remind ourselves that the brain is a delicately adjusted
+organ, which very easily gets disturbed, and that the best of us are
+liable to become the victims of absurd illusion if we habitually allow
+our imaginations to be overheated, whether by furious passion or by
+excessive indulgence in the pleasures of day-dreaming, or in the
+intoxicating mysteries of spiritualist _séances_. But if we take care to
+keep our heads cool and avoid unhealthy degrees of mental excitement, we
+need not be very anxious on the ground of our liability to this kind of
+error. As I have tried to show, our most frequent illusions are
+necessarily connected with something exceptional, either in the
+organism or in the environment. That is to say, it is of the nature of
+illusion in healthy conditions of body and mind to be something very
+occasional and relatively unimportant. Our perceptions may be regarded
+as the reaction of the mind on the impressions borne in from the
+external world, or as a process of adjustment of internal mental
+relations to external physical relations. If this process is, in the
+main, a right one, we need not greatly trouble, because it is not
+invariably so. We should accept the occasional failure of the
+intellectual mechanism as an inseparable accompaniment of its general
+efficiency.
+
+To this it must be added that many of the illusions described above can
+hardly be called cases of non-adaptation at all, since they have no
+relation to the practical needs of life, and consequently are, in a
+general way, unattended to. In other cases, again, namely, where the
+precise nature of a present sensation, being practically an unimportant
+matter, is usually unattended to, as in the instantaneous recognition of
+objects by the eye under changes of illumination, etc., the illusion is
+rather a part of the process of adaptation, since it is much more
+important to recognize the permanent object signified by the sensation
+than the precise nature of the present sensational "sign" itself.
+
+Finally, it should never be forgotten that in normal states of mind
+there is always the possibility of rectifying an illusion. What
+distinguishes abnormal from normal mental life is the persistent
+occupation of the mind by certain ideas, so that there is no room for
+the salutary corrective effect of reflection on the actual impression
+of the moment, by which we are wont to "orientate," or take our bearings
+as to the position of things about us. In sleep, and in certain
+artificially produced states, much the same thing presents itself.
+Images become realities just because they are not instantly recognized
+as such by a reference to the actual surroundings of the moment. But in
+normal waking life this power of correction remains with us. We may not
+exercise it, it is true, and thus the illusion will tend to become more
+or less persistent and recurring; for the same law applies to true and
+to false perception: repetition makes the process easier. But if we only
+choose to exert ourselves, we can always keep our illusions in a nascent
+or imperfectly developed stage. This applies not only to those
+half-illusions into which we voluntarily fall, but also to the more
+irresistible passive illusions, and those arising from an over-excited
+imagination. Even persons subject to hallucinations, like Nicolai of
+Berlin, learn to recognize the unreal character of these phantasms. On
+this point the following bit of autobiography from the pen of Coleridge
+throws an interesting light. "A lady (he writes) once asked me if I
+believed in ghosts and apparitions. I answered with truth and
+simplicity, No, madam, I have seen far too many myself."[68] However
+irresistible our sense-illusions may be, so long as we are under the
+sway of particular impressions or mental images, we can, when resolved
+to do so, undeceive ourselves by carefully attending to the actual
+state of things about us. And in many cases, when once the correction is
+made, the illusion seems an impossibility. By no effort of imagination
+are we able to throw ourselves back into the illusory mental condition.
+So long as this power of dispelling the illusion remains with us, we
+need not be alarmed at the number and variety of the momentary
+misapprehensions to which we are liable.
+
+
+
+
+CHAPTER VII.
+
+DREAMS.
+
+
+The phenomena of dreams may well seem at first sight to form a world of
+their own, having no discoverable links of connection with the other
+facts of human experience. First of all, there is the mystery of sleep,
+which quietly shuts all the avenues of sense and so isolates the mind
+from contact with the world outside. To gaze at the motionless face of a
+sleeper temporarily rapt from the life of sight, sound, and
+movement--which, being common to all, binds us together in mutual
+recognition and social action--has always something awe-inspiring. This
+external inaction, this torpor of sense and muscle, how unlike to the
+familiar waking life, with its quick responsiveness and its overflowing
+energy! And then, if we look at dreams from the inside, we seem to find
+but the reverse face of the mystery. How inexpressibly strange does the
+late night-dream seem to a person on waking! He feels he has been seeing
+and hearing things no less real than those of waking life; but things
+which belong to an unfamiliar world, an order of sights and a sequence
+of events quite unlike those of waking experience; and he asks himself
+in his perplexity where that once-visited region really lies, or by what
+magic power it was suddenly and for a moment created for his vision. In
+truth, the very name of dream suggests something remote and mysterious,
+and when we want to characterize some impression or scene which by its
+passing strangeness filled us with wonder, we naturally call it
+dream-like.
+
+
+_Theories of Dreams._
+
+The earliest theories respecting dreams illustrate very clearly this
+perception of the remoteness of dream-life from waking experience. By
+the simple mind of primitive man this dream-world is regarded as similar
+in its nature or structure to our common world, only lying remote from
+this. The savage conceives that when he falls asleep, his second self
+leaves his familiar body and journeys forth to unfamiliar regions, where
+it meets the departed second selves of his dead ancestors, and so on.
+From this point of view, the experience of the night, though equal in
+reality to that of the day, is passed in a wholly disconnected
+region.[69]
+
+A second and more thoughtful view of dreams, marking a higher grade of
+intellectual culture, is that these visions of the night are symbolic
+pictures unfolded to the inner eye of the soul by some supernatural
+being. The dream-experience is now, in a sense, less real than it was
+before, since the phantasms that wear the guise of objective realities
+are simply images spread out to the spirit's gaze, or the direct
+utterance of a divine message. Still, this mysterious contact of the
+mind with the supernatural is regarded as a fact, and so the dream
+assumes the appearance of a higher order of experience. Its one point of
+attachment to the experience of waking life lies in its symbolic
+function; for the common form which this supernatural view assumes is
+that the dream is a dim prevision of coming events. Artemidorus, the
+great authority on dream interpretation (_oneirocritics_) for the
+ancient world, actually defines a dream as "a motion or fiction of the
+soul in a diverse form signifying either good or evil to come;" and even
+a logician like Porphyry ascribes dreams to the influence of a good
+demon, who thereby warns us of the evils which another and bad demon is
+preparing for us. The same mode of viewing dreams is quite common
+to-day, and many who pride themselves on a certain intellectual culture,
+and who imagine themselves to be free from the weakness of superstition,
+are apt to talk of dreams as of something mysterious, if not distinctly
+ominous. Nor is it surprising that phenomena which at first sight look
+so wild and lawless, should still pass for miraculous interruptions of
+the natural order of events.[70]
+
+Yet, in spite of this obvious and impressive element of the mysterious
+in dream-life, the scientific impulse to illuminate the less known by
+the better known has long since begun to play on this obscure subject.
+Even in the ancient world a writer might here and there be found, like
+Democritus or Aristotle, who was bold enough to put forward a natural
+and physical explanation of dreams. But it has been the work of modern
+science to provide something like an approximate solution of the
+problem. The careful study of mental life in its intimate union with
+bodily operations, and the comparison of dream-combinations with other
+products of the imagination, normal as well as morbid, have gradually
+helped to dissolve a good part of the mystery which once hung like an
+opaque mist about the subject. In this way, our dream-operations have
+been found to have a much closer connection with our waking experiences
+than could be supposed on a superficial view. The materials of our
+dreams are seen, when closely examined, to be drawn from our waking
+experience. Our waking consciousness acts in numberless ways on our
+dreams, and these again in unsuspected ways influence our waking mental
+life.[71] Not only so, it is found that the quaint chaotic play of
+images in dreams illustrates mental processes and laws which are
+distinctly observable in waking thought. Thus, for example, the apparent
+objective reality of these visions has been accounted for, without the
+need of resorting to any supernatural agency, in the light of a vast
+assemblage of facts gathered from the by-ways, so to speak, of waking
+mental life. I need hardly add that I refer to the illusions of sense
+dealt with in the foregoing chapters.
+
+Dreams are to a large extent the semblance of external perceptions.
+Other psychical phenomena, as self-reflection, emotional activity, and
+so on, appear in dream-life, but they do so in close connection with
+these quasi-perceptions. The name "vision," given by old writers to
+dreams, sufficiently points out this close affinity of the mental
+phenomena to sense-perception; and so far as science is concerned, they
+must be regarded as a peculiar variety of sense-illusion. Hence the
+appropriateness of studying them in close connection with the illusions
+of perception of the waking state. Though marked off by the presence of
+very exceptional physiological conditions, they are largely intelligible
+by help of these physiological and psychological principles which we
+have just been considering.
+
+
+_The State of Sleep._
+
+The physiological explanation of dreams must, it is plain, set out with
+an account of the condition of the organism known as sleep. While there
+is here much that is uncertain, there are some things which are fairly
+well known. Recent physiological observation has gone to prove that
+during sleep all the activities of the organism are appreciably lowered.
+Thus, for example, according to Testa, the pulse falls by about
+one-fifth. This lowering of the organic functions appears, under
+ordinary circumstances, to increase towards midnight, after which there
+is a gradual rising.
+
+The nervous system shares in this general depression of the vital
+activities. The circulation being slower, the process of reparation and
+nutrition of the nerves is retarded, and so their degree of excitability
+diminished. This is clearly seen in the condition of the peripheral
+regions of the nervous system, including the sense-organs, which appear
+to be but very slightly acted on by their customary stimuli.
+
+The nervous centres must participate in this lethargy of the system. In
+other words, the activity of the central substance is lowered, and the
+result of this is plainly seen in what is usually thought of as the
+characteristic feature of sleep, namely, a transition from vigorous
+mental activity or intense and clear consciousness, to comparative
+inactivity or faint and obscure consciousness. The cause of this
+condition of the centres is supposed to be the same as that of the
+torpidity of all the other organs in sleep, namely, the retardation of
+the circulation. But, though there is no doubt as to this, the question
+of the proximate physiological conditions of sleep is still far from
+being settled. Whether during sleep the blood-vessels of the brain are
+fuller or less full than during waking, is still a moot point. Also the
+qualitative condition of the blood in the cerebral vessels is still a
+matter of discussion.[72]
+
+Since the effect of sleep is to lower central activity, the question
+naturally occurs whether the nervous centres are ever rendered inactive
+to such an extent as to interrupt the continuity of our conscious life.
+This question has been discussed from the point of view of the
+metaphysician, of the psychologist, and of the physiologist, and in no
+case is perfect unanimity to be found. The metaphysical question,
+whether the soul as a spiritual substance is capable of being wholly
+inactive, or whether it is not in what seem the moments of profoundest
+unconsciousness partially awake--the question so warmly discussed by the
+Cartesians, Leibnitz, etc.--need not detain us here.
+
+Of more interest to us are the psychological and the physiological
+discussions. The former seeks to settle the question by help of
+introspection and memory. On the one side, it is urged against the
+theory of unbroken mental activity, that we remember so little of the
+lowered consciousness of sleep.[73] To this it is replied that our
+forgetfulness of the contents of dream-consciousness, even if this were
+unbroken, would be fully accounted for by the great dissimilarity
+between dreaming and waking mental life. It is urged, moreover, on this
+side that a sudden rousing of a man from sleep always discovers him in
+the act of dreaming, and that this goes to prove the uniform connection
+of dreaming and sleeping. This argument, again, may be met by the
+assertion that our sense of the duration of our dreams is found to be
+grossly erroneous; that, owing to the rapid succession of the images,
+the _realization_ of which would involve a long duration, we enormously
+exaggerate the length of dreams in retrospection.[74] From this it is
+argued that the dream which is recalled on our being suddenly awakened
+may have had its whole course during the transition state of waking.
+
+Again, the fact that a man may resolve, on going to sleep, to wake at a
+certain hour, has often been cited in proof of the persistence of a
+degree of mental activity even in perfectly sound sleep. The force of
+this consideration, however, has been explained away by saying that the
+anticipation of rising at an unusual hour necessarily produces a slight
+amount of mental disquietude, which is quite sufficient to prevent sound
+sleep, and therefore to expose the sleeper to the rousing action of
+faint external stimuli.
+
+While the purely psychological method is thus wholly inadequate to solve
+the question, physiological reasoning appears also to be not perfectly
+conclusive. Many physiologists, not unnaturally desirous of upsetting
+what they regard as a gratuitous metaphysical hypothesis, have
+pronounced in favour of an absolutely dreamless or unconscious sleep.
+From the physiological point of view, there is no mystery in a totally
+suspended mental activity. On the other hand, there is much to be said
+on the opposite side, and perhaps it may be contended that the purely
+physiological evidence rather points to the conclusion that central
+activity, however diminished during sleep, always retains a minimum
+degree of intensity. At least, one would be disposed to argue in this
+way from the analogy of the condition of the other functions of the
+organism during sleep. Possibly this modicum of positive evidence may
+more than outweigh any slight presumption against the doctrine of
+unbroken mental activity drawn from the negative circumstance that we
+remember so little of our dream-life.[75]
+
+Such being the state of physiological knowledge respecting the
+immediate conditions of sleep, we cannot look for any certain
+information on the nature of that residual mode of cerebral activity
+which manifests itself subjectively in dreams. It is evident, indeed,
+that this question can only be fully answered when the condition of the
+brain as a whole during sleep is understood. Meanwhile we must be
+content with vague hypotheses.
+
+It may be said, for one thing, that during sleep the nervous substance
+as a whole is less irritable than during waking hours. That is to say, a
+greater amount of stimulus is needed to produce any conscious
+result.[76] This appears plainly enough in the case of the peripheral
+sense-organs. Although these are not, as it is often supposed, wholly
+inactive during sleep, they certainly require a more potent external
+stimulus to rouse them to action. And what applies to the peripheral
+regions applies to the centres. In truth, it is clearly impossible to
+distinguish between the diminished irritability of the peripheral and
+that of the central structures.
+
+At first sight it seems contradictory to the above to say that stimuli
+which have little effect on the centres of consciousness during waking
+life produce an appreciable result in sleep. Nevertheless, it will be
+found that this is the case. Thus organic processes which scarcely make
+themselves known to the mind in a waking state, may be shown to be the
+originators of many of our dreams. This fact can only be explained on
+the physical side by saying that the special cerebral activities
+engaged in an act of attention are greatly liberated during sleep by the
+comparative quiescence of the external senses. These activities, by
+co-operating with the faint results of the stimuli coming from the
+internal organs, serve very materially to increase their effect.
+
+Finally, it is to be observed that, while the centres thus respond with
+diminished energy to peripheral stimuli, external and internal, they
+undergo a direct, or "automatic," mode of excitation, being roused into
+activity independently of an incoming nervous impulse. This automatic
+stimulation has been plausibly referred to the action of the products of
+decomposition accumulating in the cerebral blood-vessels.[77] It is
+possible that there is something in the nature of this stimulation to
+account for the force and vividness of its conscious results, that is to
+say, of dreams.
+
+
+_The Dream State._
+
+Let us now turn to the psychic side of these conditions, that is to say,
+to the general character of the mental states known as dreams. It is
+plain that the closing of the avenues of the external senses, which is
+the accompaniment of sleep, will make an immense difference in the
+mental events of the time. Instead of drawing its knowledge from
+without, noting its bearings in relation to the environment, the mind
+will now be given over to the play of internal imagination. The activity
+of fancy will, it is plain, be unrestricted by collision with external
+fact. The internal mental life will expand in free picturesque
+movement.
+
+To say that in sleep the mind is given over to its own imaginings, is to
+say that the mental life in these circumstances will reflect the
+individual temperament and mental history. For the play of imagination
+at any time follows the lines of our past experience more closely than
+would at first appear, and being coloured with emotion, will reflect the
+predominant emotional impulses of the individual mind. Hence the saying
+of Heraclitus, that, while in waking we all have a common world, in
+sleep we have each a world of our own.
+
+This play of imagination in sleep is furthered by the peculiar attitude
+of attention. When asleep the voluntary guidance of attention ceases;
+its direction is to a large extent determined by the contents of the
+mind at the moment. Instead of holding the images and ideas, and
+combining them according to some rational end, the attention relaxes its
+energies and succumbs to the force of imagination. And thus, in sleep,
+just as in the condition of reverie or day-dreaming, there is an
+abandonment of the fancy to its own wild ways.
+
+It follows that the dream-state will not appear to the mind as one of
+fancy, but as one of actual perception, and of contact with present
+reality. Dreams are clearly illusory, and, unlike the illusions of
+waking life, are complete and persistent.[78] And the reason of this
+ought now to be clear. First of all, the mind during sleep wants what M.
+Taine calls the corrective of a present sensation. When awake under
+ordinary circumstances, any momentary illusion is at once set right by a
+new act of orientation. The superior vividness of the external
+impression cannot leave us in any doubt, when calm and self-possessed,
+whether our mental images answer to present realities or not. On the
+other hand, when asleep, this reference to a fixed objective standard is
+clearly impossible. Secondly, we may fairly argue that the mental images
+of sleep approximate in character to external impressions. This they do
+to some extent in point of intensity, for, in spite of the diminished
+excitability of the centres, the mode of stimulation which occurs in
+sleep may, as I have hinted, involve an energetic cerebral action. And,
+however this be, it is plain that the image will gain a preternatural
+force through the greatly narrowed range of attention. When the mind of
+the sleeper is wholly possessed by an image or group of images, and the
+attention kept tied down to these, there is a maximum reinforcement of
+the images. But this is not all. When the attention is thus held captive
+by the image, it approximates in character to an external impression in
+another way. In our waking state, when our powers of volition are
+intact, the external impression is characterized by its fixity or its
+obdurate resistance to our wishes. On the other hand, the mental image
+is fluent, accommodating, and disappears and reappears according to the
+direction of our volitions. In sleep, through the suspension of the
+higher voluntary power of attention, the mental image seems to lord it
+over our minds just as the actual impression of waking life.
+
+This much may suffice, perhaps, by way of a general description of the
+sleeping and dreaming state. Other points will make themselves known
+after we have studied the contents and structure of dreams in detail.
+
+Dreams are commonly classified (_e.g._ by Wundt) with hallucinations,
+and this rightly, since, as their common appellation of "vision"
+suggests, they are for the most part the semblance of percepts in the
+absence of external impressions. At the same time, recent research goes
+to show that in many dreams something answering to the "external
+impression" in waking perception is the starting-point. Consequently, in
+order to be as accurate as possible, I shall divide dreams into
+illusions (in the narrow sense) and hallucinations.
+
+
+_Dream-Illusions._
+
+By dream-illusions I mean those dreams which set out from some
+peripheral nervous stimulation, internal or external. That the organic
+processes of digestion, respiration, etc., act as stimuli to the centres
+in sleep is well known. Thus, David Hartley assigns as the second great
+source of dreams "states of the body."[79] But it is not so well known
+to what an extent our dreams may be influenced by stimuli acting on the
+exterior sense-organs. Let us first glance at the action of such
+external stimuli.
+
+
+_Action of External Stimuli._
+
+During sleep the eyes are closed, and consequently the action of
+external light on the retina impeded. Yet it is found that even under
+these circumstances any very bright light suddenly introduced is capable
+of stimulating the optic fibres, and of affecting consciousness. The
+most common form of this is the effect of bright moonlight, and of the
+early sun's rays. Krauss tells a funny story of his having once, when
+twenty-six years old, caught himself, on waking, in the act of
+stretching out his arms towards what his dream-fancy had pictured as the
+image of his mistress. When fully awake, this image resolved itself into
+the full moon.[80] It is not improbable, as Radestock remarks, that the
+rays of the sun or moon are answerable for many of the dreams of
+celestial glory which persons of a highly religious temperament are said
+to experience.
+
+External sounds, when not sufficient to rouse the sleeper, easily
+incorporate themselves into his dreams. The ticking of a watch, the
+stroke of a clock, the hum of an insect, the song of a bird, the patter
+of rain, are common stimuli to the dream-phantasy. M. Alf. Maury tells
+us, in his interesting account of the series of experiments to which he
+submitted himself in order to ascertain the result of external
+stimulation on the mind during sleep, that when a pair of tweezers was
+made to vibrate near his ear, he dreamt of bells, the tocsin, and the
+events of June, 1848.[81] Most of us, probably, have gone through the
+experience of impolitely falling asleep when some one was reading to us,
+and of having dream-images suggested by the sounds that were still
+indistinctly heard. Scherner gives an amusing case of a youth who was
+permitted to whisper his name into the ear of his obdurate mistress,
+the consequence of which was that the lady contracted a habit of
+dreaming about him, which led to a felicitous change of feeling on her
+part.[82]
+
+The two lower senses, smell and taste, seem to play a less-important
+part in the production of dream-illusions. Radestock says that the odour
+of flowers in a room easily leads to visual images of hot-houses,
+perfumery shops, and so on; and it is probable that the contents of the
+mouth may occasionally act as a stimulus to the organ of taste, and so
+give rise to corresponding dreams. As Radestock observes, these lower
+sensations do not commonly make known their quality to the sleeper's
+mind. They become transformed at once into visual, instead of into
+olfactory or gustatory percepts. That is to say, the dreamer does not
+imagine himself smelling or tasting, but seeing an object.
+
+The contact of objects with the tactual organ is one of the best
+recognized causes of dreams. M. Maury found that when his lips were
+tickled, his dream-fancy interpreted the impression as of a pitch
+plaster being torn off his face. An unusual pressure on any part of the
+body, as, for example, from contact with a fellow-sleeper, is known to
+give rise to a well-marked variety of dream. Our own limbs may even
+appear as foreign bodies to our dream-imagination, when through pressure
+they become partly paralyzed. Thus, on one occasion, I awoke from a
+miserable dream, in which I felt sure I was grasping somebody's hand in
+bed, and I was racked by terrifying conjectures as to who it might be.
+When fully awake, I discovered that I had been lying on my right side,
+and clasping the wrist of the right arm (which had been rendered
+insensible by the pressure of the body) with the left hand.
+
+In close connection with these stimuli of pressure are those of muscular
+movement, whether unimpeded or impeded. We need not enter into the
+difficult question how far the "muscular sense" is connected with the
+activity of the motor nerves, and how far with sensory fibres attached
+to the muscular or the adjacent tissues. Suffice it to say that an
+actual movement, a resistance to an attempted movement, or a mere
+disposition to movement, whether consequent on a surplus of motor energy
+or on a sensation of discomfort or fatigue in the part to be moved,
+somehow or other makes itself known to our minds, even when we are
+deprived of the assistance of vision. And these feelings of movement,
+impeded or unimpeded, are common initial impulses in our
+dream-experiences. It is quite a mistake to suppose that dreams are
+built up out of the purely passive sensations of sight and hearing. A
+close observation will show that in nearly every dream we imagine
+ourselves either moving among the objects we perceive or striving to
+move when some weighty obstacle obstructs us. All of us are familiar
+with the common forms of nightmare, in which we strive hopelessly to
+flee from some menacing evil, and this dream-experience, it may be
+presumed, frequently comes from a feeling of strain in the muscles, due
+to an awkward disposition of the limbs during sleep. The common
+dream-illusion of falling down a vast abyss is plausibly referred by
+Wundt to an involuntary extension of the foot of the sleeper.
+
+
+_Action of Internal Stimuli._
+
+Let us now pass from the action of stimuli lying outside the organism,
+to that of stimuli lying within the peripheral regions of the
+sense-organs. I have already spoken of the influence of subjective
+sensations of sight, hearing, etc., on the illusions of waking life, and
+it is now to be added that these sensations play an important part in
+our dream-life. Johannes Müller lays great prominence on the part taken
+by ocular spectra in the production of dreams. As he observes, the
+apparent rays of light, light-patches, mists of light, and so on, due to
+changes of blood-pressure in the retina, only manifest themselves
+clearly when the eyes are closed and the more powerful effect of the
+external stimulus cut off. These subjective spectra come into prominence
+in the sleepy condition, giving rise to what M. Maury calls
+"hallucinations hypnagogiques," and which he regards (after Gruithuisen)
+as the chaos out of which the dream-cosmos is evolved.[83] They are
+pretty certainly the starting-point in those picturesque dreams in which
+figure a number of bright objects, such as beautiful birds, butterflies,
+flowers, or angels.
+
+That the visual images of our sleep do often involve the peripheral
+regions of the organ of sight, seems to be proved by the singular fact
+that they sometimes persist after waking. Spinoza and Jean Paul Richter
+both experienced this survival of dream-images. Still more pertinent is
+the fact that the effects of retinal fatigue are producible by
+dream-images. The physiologist Gruithuisen had a dream, in which the
+principal feature was a violet flame, and which left behind it, _after
+waking_, for an appreciable duration, a complementary image of a yellow
+spot.[84]
+
+Subjective auditory sensations appear to be much less frequent causes of
+dream-illusions than corresponding visual sensations. Yet the rushing,
+roaring sound caused by the circulation of the blood in the ear is,
+probably, a not uncommon starting-point in dreams. With respect to
+subjective sensations of smell and taste, there is little to be said. On
+the other hand, subjective sensations due to varying conditions in the
+skin are a very frequent exciting cause of dreams. Variations in the
+state of tension of the skin, brought about by alteration of position,
+changes in the character of the circulation, the irradiation of heat to
+the skin or the loss of the same, chemical changes,--these are known to
+give rise to a number of familiar sensations, including those of
+tickling, itching, burning, creeping, and so on; and the effects of
+these sensations are distinctly traceable in our dreams. For example,
+the exposure of a part of the body through a loss of the bed-clothes is
+a frequent excitant of distressing dreams. A cold foot suggests that the
+sleeper is walking over snow or ice. On the other hand, if the cold foot
+happens to touch a warm part of the body, the dream-fancy constructs
+images of walking on burning lava, and so on.
+
+These sensations of the skin naturally conduct us to the organic
+sensations as a whole; that is to say, the feelings connected with the
+varying condition of the bodily organs. These include the feelings which
+arise in connection with the processes of digestion, respiration, and
+circulation, and the condition of various organs according to their
+state of nutrition, etc. During our waking life these organic feelings
+coalesce for the most part, forming as the "vital sense" an obscure
+background for our clear discriminative consciousness, and only come
+forward into this region when very exceptional in character, as when
+respiration or digestion is impeded, or when we make a special effort of
+attention to single them out.[85] When we are asleep, however, and the
+avenues of external perception are closed, they assume greater
+prominence and distinctness. The centres, no longer called upon to react
+on stimuli coming from without the organism, are free to react on
+stimuli coming from its hidden recesses. So important a part, indeed, do
+these organic feelings take in the dream-drama, that some writers are
+disposed to regard them as the great, if not the exclusive, cause of
+dreams. Thus, Schopenhauer held that the excitants of dreams are
+impressions received from the internal regions of the organism through
+the sympathetic nervous system.[86]
+
+It is hardly necessary, perhaps, to give many illustrations of the
+effect of such organic sensations on our dreams. Among the most common
+provocatives of dreams are sensations connected with a difficulty in
+breathing, due to the closeness of the air or to the pressure of the
+bed-clothes on the mouth. J. Börner investigated the influence of these
+circumstances by covering with the bed-clothes the mouth and a part of
+the nostrils of persons who were sound asleep. This was followed by a
+protraction of the act of breathing, a reddening of the face, efforts to
+throw off the clothes, etc. On being roused, the sleeper testified that
+he had experienced a nightmare, in which a horrid animal seemed to be
+weighing him down.[87] Irregularity of the heart's action is also a
+frequent cause of dreams. It is not improbable that the familiar
+dream-experience of flying arises from disturbances of the respiratory
+and circulatory movements.
+
+Again, the effects of indigestion, and more particularly stomachic
+derangement, on dreams are too well known to require illustration. It
+may be enough to allude to the famous dream which Hood traces to an
+excessive indulgence at supper. It is known that the varying condition
+of the organs of secretion influences our dream-fancy in a number of
+ways.
+
+Finally, it is to be observed that an injury done to any part of the
+organism is apt to give rise to appropriate dream-images. In this way,
+very slight disturbances which would hardly affect waking consciousness
+may make themselves felt during sleep. Thus, for example, an incipient
+toothache has been known to suggest that the teeth are being
+extracted.[88]
+
+It is worth observing that the interpretation of these various orders of
+sensations by the imagination of the dreamer takes very different forms
+according to the person's character, previous experience, ruling
+emotions, and so on. This is what is meant by saying that during sleep
+every man has a world of his own, whereas, when awake, he shares in the
+common world of perception.
+
+
+_Dream-Exaggeration._
+
+It is to be noticed, further, that this interpretation of sensation
+during sleep is uniformly a process of exaggeration.[89] The exciting
+causes of the feeling of discomfort, for example, are always absurdly
+magnified. The reason of this seems to be that, owing to the condition
+of the mind during sleep, the nature of the sensation is not clearly
+recognizable. Even in the case of familiar external impressions, such as
+the sound of the striking of a clock, there appears to be wanting that
+simple process of reaction by which, in a waking condition of the
+attention, a sense-impression is instantly discriminated and classed. In
+sleep, as in the artificially induced hypnotic condition, the slighter
+differences of quality among sensations are not clearly recognized. The
+activity of the higher centres, which are concerned in the finer
+processes of discrimination and classification, being greatly reduced,
+the impression may be said to come before consciousness as something
+novel and unfamiliar. And just as we saw that in waking life novel
+sensations agitate the mind, and so lead to an exaggerated mode of
+interpretation; so here we see that what is unfamiliar disturbs the
+mind, rendering it incapable of calm attention and just interpretation.
+
+This failure to recognize the real nature of an impression is seen most
+conspicuously in the case of the organic sensations. As I have remarked,
+these constitute for the most part, in waking life, an undiscriminated
+mass of obscure feeling, of which we are only conscious as the mental
+tone of the hour. And in the few instances in which we do attend to them
+separately, whether through their exceptional intensity or in
+consequence of an extraordinary effort of discriminative attention, we
+can only be said to perceive them, that is, recognize their local
+origin, very vaguely. Hence, when asleep, these sensations get very
+oddly misinterpreted.
+
+The localization of a bodily sensation in waking life means the
+combination of a tactual and a visual image with the sensation. Thus, my
+recognition of a twinge of toothache as coming from a certain tooth,
+involves representations of the active and passive sensations which
+touching and looking at the tooth would yield me. That is to say, the
+feeling instantly calls up a compound mental image exactly answering to
+a visual percept. This holds good in dream-interpretation too; the
+interpretation is effected by means of a visual image. But since the
+feeling is only very vaguely recognized, this visual image does not
+answer to the bodily part concerned. Instead of this, the fancy of the
+dreamer constructs some visual image which bears a vague resemblance to
+the proper one, and is generally, if not always, an exaggeration of this
+in point of extensive magnitude, etc. For example, a sensation arising
+from pressure on the bladder, being dimly connected with the presence of
+a fluid, calls up an image of a flood, and so on.
+
+This mode of dream-interpretation has by some writers been erected into
+the typical mode, under the name of dream-symbolism. Thus Scherner, in
+his interesting though somewhat fanciful work, _Das Leben des Traumes_,
+contends that the various regions of the body regularly disclose
+themselves to the dream-fancy under the symbol of a building or group of
+buildings; a pain in the head calling up, for example, the image of
+spiders on the ceiling, intestinal sensations exciting an image of a
+narrow alley, and so on. Such theories are clearly an exaggeration of
+the fact that the localization of our bodily sensations during sleep is
+necessarily imperfect.[90]
+
+In many cases the image called up bears on its objective side no
+discoverable resemblance to that of the bodily region or the exciting
+cause of the sensation. Here the explanation must be looked for in the
+subjective side of the sensation and mental image, that is to say, in
+their emotional quality, as pleasurable or painful, distressing,
+quieting, etc. It is to be observed, indeed, that in natural sleep, as
+in the condition known as hypnotism, while differences of specific
+quality in the sense-impressions are lost, the broad difference of the
+pleasurable and the painful is never lost. It is, in fact, the
+subjective emotional side of the sensation that uniformly forces itself
+into consciousness. This being so, it follows that, speaking generally,
+the sensations of sleep, both external and internal, or organic, will be
+interpreted by what G.H. Lewes has called "an analogy of feeling;" that
+is to say, by means of a mental image having some kindred emotional
+character or colouring.
+
+Now, the analogy between the higher emotional and the bodily states is a
+very close one. A sensation of obstruction in breathing has its exact
+analogue in a state of mental embarrassment, a sensation of itching its
+counterpart in mental impatience, and so on. And since these emotional
+experiences are deeper and fuller than the sensations, the tendency to
+exaggerate the nature and causes of these last would naturally lead to
+an interpretation of them by help of these experiences. In addition to
+this, the predominance of visual imagery in sleep would aid this
+transformation of a bodily sensation into an emotional experience, since
+visual perceptions have, as their accompaniments of pleasure and pain,
+not sensations, but emotions.[91]
+
+Since in this vague interpretation of bodily sensation the actual
+impression is obscured, and not taken up as an integral part into the
+percept, it is evident that we cannot, strictly speaking, call the
+process an imitation of an act of perception, that is to say, an
+illusion. And since, moreover, the visual image by which the sensation
+is thus displaced appears as a present object, it would, of course, be
+allowable to speak of this as an hallucination. This substitution of a
+more or less analogous visual image for that appropriate to the
+sensation forms, indeed, a transition from dream-illusion, properly so
+called, to dream-hallucination.
+
+
+_Dream-Hallucinations._
+
+On the physical side, these hallucinations answer to cerebral
+excitations which are central or automatic, not depending on movements
+transmitted from the periphery of the nervous system. Of these
+stimulations some appear to be direct, and due to unknown influences
+exerted by the state of nutrition of the cerebral elements, or the
+action of the contents of the blood-vessels on these elements.
+
+
+_Effects of Direct Central Stimulation._
+
+That such action does prompt a large number of dream-images may be
+regarded as fairly certain. First of all, it seems impossible to account
+for all the images of dream-fancy as secondary phenomena connected by
+links of association with the foregoing classes of sensation. However
+fine and invisible many of the threads which hold together our ideas may
+be, they will hardly explain the profusion and picturesque variety of
+dream-imagery. Secondly, we are able in certain cases to infer with a
+fair amount of certainty that a dream-image is due to such central
+stimulation. The common occurrence that we dream of the more stirring
+events, the anxieties and enjoyments of the preceding day, appears to
+show that when the cerebral elements are predisposed to a certain kind
+of activity, as they are after having been engaged for some time in this
+particular work, they are liable to be excited by some stimulus brought
+directly to bear on them during sleep. And if this is so, it is not
+improbable that many of the apparently forgotten images of persons and
+places which return with such vividness in dreams are excited by a mode
+of stimulation which is for the greater part confined to sleep. I say
+"for the greater part," because even in our indolent, listless moments
+of waking existence such seemingly forgotten ideas sometimes return as
+though by a spontaneous movement of their own and by no discoverable
+play of association.
+
+It may be well to add that this immediate revival of impressions
+previously received by the brain includes not only the actual
+perceptions of waking life, but also the ideas derived from others, the
+ideal fancies supplied by works of fiction, and even the images which
+our unaided waking fancy is wont to shape for itself. Our daily
+conjectures as to the future, the communications to us by others of
+their thoughts, hopes, and fears,--these give rise to numberless vague
+fugitive images, any one of which may become distinctly revived in
+sleep.[92] This throws light on the curious fact that we often dream of
+experiences and events quite unlike those of our individual life. Thus,
+for example, the common construction by the dream-fancy of the
+experience of flight in mid-air, and the creation of those weird forms
+which the terror of a nightmare is wont to bring in its train, seem to
+point to the past action of waking fancy. To imagine one's self flying
+when looking at a bird is probably a common action with all persons, at
+least in their earlier years, and images of preternaturally horrible
+beings are apt to be supplied to most of us some time during life by
+nurses or by books.
+
+
+_Indirect Central Stimulation._
+
+Besides these direct central stimulations, there are others which, in
+contradistinction, may be called indirect, depending on some previous
+excitation. These are, no doubt, the conditions of a very large number
+of our dream-images. There must, of course, be some primary cerebral
+excitation, whether that of a present peripheral stimulation, or that
+which has been termed central and spontaneous; but when once this first
+link of the imaginative chain is supplied, other links may be added in
+large numbers through the operation of the forces of association. One
+may, indeed, safely say that the large proportion of the contents of
+every dream arise in this way.
+
+The very simplest type of dream excited by a present sensation contains
+these elements. To take an example, I once dreamt, as a consequence of
+the loud barking of a dog, that a dog approached me when lying down, and
+began to lick my face. Here the play of the associative forces was
+apparent: a mere sensation of sound called up the appropriate visual
+image, this again the representation of a characteristic action, and so
+on. So it is with the dreams whose first impulse is some central or
+spontaneous excitation. A momentary sight of a face or even the mention
+of a name during the preceding day may give the start to dream-activity;
+but all subsequent members of the series of images owe their revival to
+a tension, so to speak, in the fine threads which bind together, in so
+complicated a way, our impressions and ideas.
+
+Among the psychic accompaniments of these central excitations visual
+images, as already hinted, fill the most conspicuous place. Even
+auditory images, though by no means absent, are much less numerous than
+visual. Indeed, when there are the conditions for the former, it
+sometimes happens that the auditory effect transforms itself into a
+visual effect. An illustration of this occurred in my own experience.
+Trying to fall asleep by means of the well-known device of counting, I
+suddenly found myself losing my hold on the faint auditory effects, my
+imagination transforming them into a visual spectacle, under the form of
+a path of light stretching away from me, in which the numbers appeared
+under the grotesque form of visible objects, tumbling along in glorious
+confusion.
+
+Next to these visual phantasms, certain motor hallucinations seem to be
+most prominent in dreams. By a motor hallucination, I mean the illusion
+that we are actually moving when there is no peripheral excitation of
+the motor organ. Just as the centres concerned in passive sensation are
+susceptible of central stimulation, so are the centres concerned in
+muscular sensation. A mere impulse in the centres of motor innervation
+(if we assume these to be the central seat of the muscular feelings) may
+suffice to give rise to a complete representation of a fully executed
+movement. And thus in our sleep we seem to walk, ride, float, or fly.
+
+The most common form of motor hallucination is probably the vocal. In
+the social encounters which make up so much of our sleep-experience, we
+are wont to be very talkative. Now, perhaps, we find ourselves zealously
+advocating some cause, now very fierce in denunciation, now very amusing
+in witty repartee, and so on. This imagination of ourselves as speaking,
+as distinguished from that of hearing others talking, must, it is clear,
+involve the excitation of the structures engaged in the production of
+the muscular feelings which accompany vocal action, as much as, if not
+more than, the auditory centres. And the frequency of this kind of
+dream-experience may be explained, like that of visual imagery, by the
+habits of waking life. The speech impulse is one of the most deeply
+rooted of all our impulses, and one which has been most frequently
+exercised in waking life.
+
+_Combination of Dream-Elements._
+
+It is commonly said that dreams are a grotesque dissolution of all
+order, a very chaos and whirl of images without any discoverable
+connection. On the other hand, a few writers claim for the mind in sleep
+a power of arranging and grouping its incongruous elements in definite
+and even life-like pictures. Each of these views is correct within
+certain limits; that is to say, there are dreams in which the strangest
+disorder seems to prevail, and others in which one detects the action of
+a central control. Yet, speaking generally, sequences of dream-images
+will be found to be determined by certain circumstances and laws, and so
+far not to be haphazard or wholly chaotic. We have now to inquire into
+the laws of these successions; and, first of all, we may ask how far the
+known laws of association, together with the peculiar conditions of the
+sleeping state, are able to account for the various modes of
+dream-combination. We have already regarded mental association as
+furnishing a large additional store of dream-imagery; we have now to
+consider it as explaining the sequences and concatenations of our
+dream-elements.
+
+
+_Incoherence of Dreams._
+
+First of all, then, let us look at the chaotic and apparently lawless
+side of dreaming, and see whether any clue is discoverable to the centre
+of this labyrinth. In the case of all the less elaborately ordered
+dreams, in which sights and sounds appear to succeed one another in the
+wildest dance (which class of dreams probably belongs to the deeper
+stages of sleep), the mind may with certainty be regarded as purely
+passive, and the mode of sequence may be referred to the action of
+association complicated by the ever-recurring introduction of new
+initial impulses, both peripheral and central. These are the dreams in
+which we are conscious of being perfectly passive, either as spectators
+of a strange pageant, or as borne away by some apparently extraneous
+force through a series of the most diverse experiences. The flux of
+images in these dreams is very much the same as that in certain waking
+conditions, in which we relax attention, both external and internal, and
+yield ourselves wholly to the spontaneous play of memory and fancy.
+
+It is plain at a glance that the simultaneous concurrence of wholly
+disconnected initial impulses will serve to impress a measure of
+disconnectedness on our dream-images. From widely remote parts of the
+organism there come impressions which excite each its peculiar visual or
+other image according as its local origin or its emotional tone is the
+more distinctly present to consciousness. Now it is a subjective ocular
+sensation suggesting a bouquet of lovely flowers, and close on its heels
+comes an impression from the organs of digestion suggesting all manner
+of obstacles, and so our dream-fancy plunges from a vision of flowers to
+one of dreadful demons.
+
+Let us now look at the way in which the laws of association working on
+the incongruous elements thus cast up into our dream-consciousness, will
+serve to give a yet greater appearance of disorder and confusion to our
+dream-combinations. According to these laws, any idea may, under
+certain circumstances, call up another, if the corresponding impressions
+have only once occurred together, or if the ideas have any degree of
+resemblance, or, finally, if only they stand in marked contrast with one
+another. Any accidental coincidence of events, such as meeting a person
+at a particular foreign resort, and any insignificant resemblance
+between objects, sounds, etc., may thus supply a path, so to speak, from
+fact to dream-fancy.
+
+In our waking states these innumerable paths of association are
+practically closed by the supreme energy of the coherent groups of
+impressions furnished us from the world without through our organs of
+sense, and also by the volitional control of internal thought in
+obedience to the pressure of practical needs and desires. In dream-life
+both of these influences are withdrawn, so that delicate threads of
+association, which have no chance of exerting their pull, so to speak,
+in our waking states, now make known their hidden force. Little wonder,
+then, that the filaments which bind together these dream-successions
+should escape detection, since even in our waking thought we so often
+fail to see the connection which makes us pass in recollection from a
+name to a visible scene or perhaps to an emotional vibration.
+
+It is worth noting that the origin of an association is often to be
+looked for in one of those momentary half-conscious acts of waking
+imagination to which reference has already been made. A friend, for
+example, has been speaking to us of some common acquaintance, remarking
+on his poor health. The language calls up, vaguely, a visual
+representation of the person sinking in health and dying. An
+association will thus be formed between this person and the idea of
+death. A night or two after, the image of this person somehow recurs to
+our dream-fancy, and we straightway dream that we are looking at his
+corpse, watching his funeral, and so on. The links of the chain which
+holds together these dream-images were really forged, in part, in our
+waking hours, though the process was so rapid as to escape our
+attention. It may be added, that in many cases where a juxtaposition of
+dream-images seems to have no basis in waking life, careful reflection
+will occasionally bring to light some actual conjunction of impressions
+so momentary as to have faded from our recollection.
+
+We must remember, further, how great an apparent disorder will invade
+our imaginative dream-life when the binding force of resemblance has
+unchecked play. In waking thought we have to connect things according to
+their essential resemblances, classifying objects and events for
+purposes of knowledge or action, according to their widest or their most
+important points of similarity. In sleep, on the contrary, the slightest
+touch of resemblance may engage the mind and affect the direction of
+fancy. In a sense we may be said, when dreaming, to discover mental
+affinities between impressions and feelings, including those subtle
+links of emotional analogy of which I have already spoken. This effect
+is well illustrated in a dream recorded by M. Maury, in which he passed
+from one set of images to another through some similarity of names, as
+that between _corps_ and _cor_. Such a movement of fancy would, of
+course, be prevented in full waking consciousness by a predominant
+attention to the meaning of the sounds.
+
+It will be possible, I think, after a habit of analyzing one's dreams in
+the light of preceding experience has been formed, to discover in a good
+proportion of cases some hidden force of association which draws
+together the seemingly fortuitous concourse of our dream-atoms. That we
+should expect to do so in every case is unreasonable, since, owing to
+the numberless fine ramifications which belong to our familiar images,
+many of the paths of association followed by our dream-fancy cannot be
+afterwards retraced.
+
+To illustrate the odd way in which our images get tumbled together
+through the action of occult association forces, I will record a dream
+of my own. I fancied I was at the house of a distinguished literary
+acquaintance, at her usual reception hour. I expected the friends I was
+in the habit of meeting there. Instead of this, I saw a number of
+commonly dressed people having tea. My hostess came up and apologized
+for having asked me into this room. It was, she said, a tea-party which
+she prepared for poor people at sixpence a head. After puzzling over
+this dream, I came to the conclusion that the missing link was a verbal
+one. A lady who is a connection of my friend, and bears the same name,
+assists her sister in a large kind of benevolent scheme. I may add that
+I had not, so far as I could recollect, had occasion very recently to
+think of this benevolent friend, but I had been thinking of my literary
+friend in connection with her anticipated return to town.
+
+In thus seeking to trace, amid the superficial chaos of dream-fancy,
+its hidden connections, I make no pretence to explain why in any given
+case these particular paths of association should be followed, and more
+particularly why a slender thread of association should exert a pull
+where a stronger cord fails to do so. To account for this, it would be
+necessary to call in the physiological hypothesis that among the nervous
+elements connected with a particular element, _a_, already excited,
+some, as _m_ and _n_, are at the moment, owing to the state of their
+nutrition or their surrounding influences, more powerfully predisposed
+to activity than other elements, as _b_ and _c_.
+
+The subject of association naturally conducts us to the second great
+problem in the theory of dreams--the explanation of the order in which
+the various images group themselves in all our more elaborate dreams.
+
+
+_Coherence of Dreams._
+
+A fully developed dream is a complex of many distinct illusory
+sense-presentations: in this respect it differs from the illusions of
+normal waking life, which are for the most part single and isolated. And
+this complex of quasi-presentations appears somehow or other to fall
+together into one whole scene or series of events, which, though it may
+be very incongruous and absurdly impossible from a waking point of view,
+nevertheless makes a single object for the dreamer's internal vision,
+and has a certain degree of artistic unity. This plastic force, which
+selects and binds together our unconnected dream-images, has frequently
+been referred to as a mysterious spiritual faculty, under the name of
+"creative fancy." Thus Cudworth remarks, in his _Treatise concerning
+Eternal and Immutable Morality_: "That dreams are many times begotten by
+the phantastical power of the soul itself ... is evident from the
+orderly connection and coherence of imaginations which many times are
+continued in a long chain or series." One may find a good deal of
+mystical writing on the nature and activity of this faculty, especially
+in German literature. The explanation of this element of organic unity
+in dreams is, it may be safely said, the crux in the science of dreams.
+That the laws of psychology help us to understand the sequences of
+dream-images, we have seen. What we have now to ask is whether these
+laws throw any light on the orderly grouping of the elements so brought
+up in consciousness in the form of a connected experience.
+
+It is to be remarked at the outset that a singular kind of unity is
+sometimes given to our dream-combinations by a total or partial
+coalescence of different images. The conditions of such coalescence have
+been referred to already.[93] Simultaneous impressions or images will
+always tend to coalesce with a force which varies directly as the degree
+of their similarity. Sometimes this coalescence is instantaneous and not
+made known to consciousness. Thus, Radestock suggests that if the mind
+of the sleeper is simultaneously invaded by an unpleasant sensation
+arising out of some disturbance of the functions of the skin, and a
+subjective visual sensation, the resulting mental image may be a
+combination of the two, under the form of a caterpillar creeping over
+the bodily surface. And the coalescence may even be prepared by
+sub-conscious operations of waking imagination. Thus, for example, I
+once spoke about the cheapness of hares to a member of my family, who
+somewhat grimly suggested that they were London cats. I did not dwell on
+the idea, but the following night I dreamt that I saw a big hybrid
+creature, half hare, half cat, sniffing about a cottage. As it stood on
+its hind legs and took a piece of food from a window-ledge, I became
+sure that it was a cat. Here it is plain that the cynical observation of
+my relative had, at the moment, partially excited an image of this
+feline hare. In some dreams, again, we may become aware of the process
+of coalescence, as when persons who at one moment were seen to be
+distinct appear to our dream-fancy to run together in some third person.
+
+A very similar kind of unification takes place between sequent images
+under the form of transformation. When two images follow one another
+closely, and have anything in common, they readily assume the form of a
+transmutation. There is a sort of overlapping of the mental images, and
+so an appearance of continuity produced in some respects analogous to
+that which arises in the wheel-of-life (thaumatrope) class of
+sense-illusions. This would seem to account for the odd transformations
+of personality which not unfrequently occur in dreams, in which a person
+appears, by a kind of metempsychosis, to transfer his physical ego to
+another, and in which the dreamer's own bodily phantom plays similar
+freaks. And the same principle probably explains those dissolving-view
+effects which are so familiar an accompaniment of dream-scenery.[94]
+
+But passing from this exceptional kind of unity in dreams, let us
+inquire how the heterogeneous elements of our dream-fancy become ordered
+and arranged when they preserve their separate existence. If we look
+closely at the structure of our more finished dreams, we find that the
+appearance of harmony, connectedness, or order, may be given in one of
+two ways. There may, first of all, be a subjective harmony, the various
+images being held together by an emotional thread. Or there may,
+secondly, be an objective harmony, the parts of the dream, though
+answering to no particular experiences of waking life, bearing a certain
+resemblance to our habitual modes of experience. Let us inquire into the
+way in which each kind of order is brought about.
+
+
+_Lyrical Element in Dreams._
+
+The only unity that belongs to many of our dreams is a subjective
+emotional unity. This is the basis of harmony in lyrical poetry, where
+the succession of images turns mainly on their emotional colouring.
+Thus, the images that float before the mind of the Poet Laureate, in his
+_In Memoriam_, clearly have their link of connection in their common
+emotional tone, rather than in any logical continuity. Dreaming has been
+likened to poetic composition, and certainly many of our dreams are
+built upon a groundwork of lyrical feeling. They might be marked off,
+perhaps, as our lyrical dreams.
+
+The way in which this emotional force acts in these cases has already
+been hinted at. We have seen that the analogy of feeling is a common
+link between dream-images. Now, if any shade of feeling becomes fixed
+and dominant in the mind, it will tend to control all the images of the
+time, allowing certain congruous ones to enter, and excluding
+others.[95] If, for example, a feeling of distress occupies the mind,
+distressing images will have the advantage in the struggle for existence
+which goes on in the world of mind as well as in that of matter. We may
+say that attention, which is here wholly a passive process, is
+controlled by the emotion of the time, and bent in the direction of
+congruent or harmonious images.
+
+Now, a ground-tone of feeling of a certain complexion, answering to the
+sum of sensations arising in connection with the different organic
+processes of the time, is a very frequent foundation of our
+dream-structure. So frequent is it, indeed, that one might almost say
+there is no dream in which it is not one great determining factor. The
+analysis of a very large number of dreams has convinced me that traces
+of this influence are discoverable in a great majority.
+
+I will give a simple illustration of this lyrical type of dream. A
+little girl of about four years and three-quarters went with her parents
+to Switzerland. On their way she was taken to the cathedral at
+Strasburg, and saw the celebrated clock strike, and the figures of the
+Apostles come out, etc. In Switzerland she stayed at Gimmelwald, near
+Mürren, opposite a fine mass of snowy mountains. One morning she told
+her father that she had had "such a lovely dream." She fancied she was
+on the snow-peaks with her nurse, and walked on to the sky. There came
+out of the sky "such beautiful things," just like the figures of the
+clock. This vision of celestial things was clearly due to the fact that
+both the clock and the snow-peaks touching the blue sky had powerfully
+excited her imagination, filling her with much the same kind of emotion,
+namely, wonder, admiration, and longing to reach an inaccessible height.
+
+Our feelings commonly have a gradual rise and fall, and the organic
+sensations which so often constitute the emotional basis of our lyrical
+dreams generally have stages of increasing intensity. Moreover, such a
+persistent ground-feeling becomes reinforced by the images which it
+sustains in consciousness. Hence a certain _crescendo_ character in our
+emotional dreams, or a gradual rise to some culminating point or climax.
+
+This phase of dream can be illustrated from the experience of the same
+little girl. When just five years old, she was staying at Hampstead,
+near a church which struck the hours somewhat loudly. One morning she
+related the following dream to her father (I use her own language). The
+biggest bells in the world were ringing; when this was over the earth
+and houses began to tumble to pieces; all the seas, rivers, and ponds
+flowed together, and covered all the land with black water, as deep as
+in the sea where the ships sail; people were drowned; she herself flew
+above the water, rising and falling, fearing to fall in; she then saw
+her mamma drowned, and at last flew home to tell her papa. The gradual
+increase of alarm and distress expressed in this dream, having its
+probable cause in the cumulative effect of the disturbing sound of the
+church bells, must be patent to all.
+
+The following rather comical dream illustrates quite as clearly the
+growth of a feeling of irritation and vexation, probably connected with
+the development of some slightly discomposing organic sensation. I
+dreamt I was unexpectedly called on to lecture to a class of young
+women, on Herder. I began hesitatingly, with some vague generalities
+about the Augustan age of German literature, referring to the three
+well-known names of Lessing, Schiller, and Goethe. Immediately my
+sister, who suddenly appeared in the class, took me up, and said she
+thought there was a fourth distinguished name belonging to this period.
+I was annoyed at the interruption, but said, with a feeling of triumph,
+"I suppose you mean Wieland?" and then appealed to the class whether
+there were not twenty persons who knew the names I had mentioned to one
+who knew Wieland's name. Then the class became generally disorderly. My
+feeling of embarrassment gained in depth. Finally, as a climax, several
+quite young girls, about ten years and less, came and joined the class.
+The dream broke off abruptly as I was in the act of taking these
+children to the wife of an old college tutor, to protest against their
+admission.
+
+It is worth noting, perhaps, that in this evolution of feeling in
+dreaming the quality of the emotion may vary within certain limits. One
+shade of feeling may be followed by another and kindred shade, so that
+the whole dream still preserves a degree, though a less obvious degree,
+of emotional unity. Thus, for example, a lady friend of mine once dreamt
+that she was in church, listening to a well-known novelist of the more
+earnest sort, preaching. A wounded soldier was brought in to be shot,
+because he was mortally wounded, and had distinguished himself by his
+bravery. He was then shot, but not killed, and, rolling over in agony,
+exclaimed, "How long!" The development of an extreme emotion of horror
+out of the vague feeling of awe which is associated with a church, gives
+a curious interest to this dream.
+
+
+_Verisimilitude in Dreams._
+
+I must not dwell longer on this emotional basis of dreams, but pass to
+the consideration of the second and objective kind of unity which
+characterizes many of our more elaborate dream-performances. In spite of
+all that is fitful and grotesque in dream-combination, it still
+preserves a distant resemblance to our actual experience. Though no
+dream reproduces a particular incident or chain of incidents in this
+experience, though the dream-fancy invariably transforms the particular
+objects, relations, and events of waking life, it still makes the order
+of our daily experience its prototype. It fashions its imaginary world
+on the model of the real. Thus, objects group themselves in space, and
+act on one another conformably to these perceived space-relations;
+events succeed one another in time, and are often seen to be connected;
+men act from more or less intelligible motives, and so on. In this way,
+though the dream-fancy sets at nought the particular relations of our
+experience, it respects the general and constant relations. How are we
+to account for this?
+
+It is said by certain philosophers that this superposition of the
+relations of space, time, causation, etc., on the products of our
+dream-fancy is due to the fact that all experience arises by a synthesis
+of mental forms with the chaotic matter of sense-impressions. These
+philosophers allow, however, that all particular connections are
+determined by experience. Accordingly, what we have to do here is to
+inquire how far this scientific method of explaining mental connections
+by facts of experience will carry us. In other words, we have to ask
+what light can be thrown on these tendencies of dream-imagination by
+ascertained psychological laws, and more particularly by what are known
+as the laws of association.
+
+These laws tell us that of two mental phenomena which occur together,
+each will tend to recall the other whenever it happens to be revived. On
+the physiological side, this means that any two parts of the nervous
+structures which have acted together become in some way connected, so
+that when one part begins to work the other will tend to work also. But
+it is highly probable that a particular structure acts in a great many
+different ways. Thus, it may be stimulated by unlike modes of stimuli,
+or it may enter into very various connections with other structures.
+What will follow from this? One consequence would appear to be that
+there will be developed an organic connection between the two
+structures, of such a kind that whenever one is excited the other will
+be disposed to act somehow and anyhow, even when there is nothing in the
+present mode of activity of the first structure to determine the second
+to act in some one definite way, in other words, when this mode of
+activity is, roughly speaking, novel.
+
+Let me illustrate this effect in one of the simplest cases, that of the
+visual organ. If, when walking out on a dark night, a few points in my
+retina are suddenly stimulated by rays of light, and I recognize some
+luminous object in a corresponding direction, I am prepared to see
+something above and below, to the right and to the left of this object.
+Why is this? There may from the first have been a kind of innate
+understanding among contiguous optic fibres, predisposing them to such
+concerted action. But however this be, this disposition would seem to
+have been largely promoted by the fact that, throughout my experience,
+the stimulation of any retinal point has been connected with that of
+adjoining points, either simultaneously by some second object, or
+successively by the same object as the eye moves over it, or as the
+object itself moves across the field of vision.
+
+When, therefore, in sleep any part of the optic centres is excited in a
+particular way, and the images thus arising have their corresponding
+loci in space assigned to them, there will be a disposition to refer any
+other visual images which happen at the moment to arise in consciousness
+to adjacent parts of space. The character of these other images will be
+determined by other special conditions of the moment; their locality or
+position in space will be determined by this organic connection. We may,
+perhaps, call these tendencies to concerted action of some kind general
+associative dispositions.
+
+Just as there are such dispositions to united action among various parts
+of one organ of sense, so there may be among different organs, which are
+either connected originally in the infant organism, or have
+communications opened up by frequent coexcitation of the two. Such links
+there certainly are between the organs of taste and smell, and between
+the ear and the muscular system in general, and more particularly the
+vocal organ.[96] A new odour often sets us asking how the object would
+taste, and a series of sounds commonly disposes us to movement of some
+kind or another. How far there may be finer threads of connection
+between other organs, such as the eye and the ear, which do not betray
+themselves amid the stronger forces of waking mental life, one cannot
+say. Whatever their number, it is plain that they will exert their
+influence within the comparatively narrow limits of dream-life, serving
+to impress a certain character on the images which happen to be called
+up by special circumstances, and giving to the combination a slight
+measure of congruity. Thus, if I were dreaming that I heard some lively
+music, and at the same time an image of a friend was anyhow excited, my
+dream-fancy might not improbably represent this person as performing a
+sequence of rhythmic movements, such as those of riding, dancing, etc.
+
+A narrower field for these general associative dispositions may be found
+in the tendency, on the reception of an impression of a given character,
+to look for a certain kind of second impression; though the exact nature
+of this is unknown. Thus, for example, the form and colour of a new
+flower suggest a scent, and the perception of a human form is
+accompanied by a vague representation of vocal utterances. These general
+tendencies of association appear to me to be most potent influences in
+our dream-life. The many strange human forms which float before our
+dream-fancy are apt to talk, move, and behave like men and women in
+general, however little they resemble their actual prototypes, and
+however little individual consistency of character is preserved by each
+of them. Special conditions determine what they shall say or do; the
+general associative disposition accounts for their saying or doing
+something.
+
+We thus seem to find in the purely passive processes of association some
+ground for that degree of natural coherence and rational order which our
+more mature dreams commonly possess. These processes go far to explain,
+too, that odd mixture of rationality with improbability, of natural
+order and incongruity, which characterizes our dream-combinations.
+
+
+_Rational Construction in Dreams._
+
+Nevertheless, I quite agree with Herr Volkelt that association, even in
+the most extended meaning, cannot explain all in the shaping of our
+dream-pictures. The "phantastical power" which Cudworth talks about
+clearly includes something besides. It is an erroneous supposition that
+when we are dreaming there is a complete suspension of the voluntary
+powers, and consequently an absence of all direction of the intellectual
+processes. This supposition, which has been maintained by numerous
+writers, from Dugald Stewart downwards, seems to be based on the fact
+that we frequently find ourselves in dreams striving in vain to move the
+whole body or a limb. But this only shows, as M. Maury remarks in the
+work already referred to, that our volitions are frustrated through the
+inertia of our bodily organs, not that these volitions do not take
+place. In point of fact, the dreamer, not to speak of the somnambulist,
+is often conscious of voluntarily going through a series of actions.
+This exercise of volition is shown unmistakably in the well-known
+instances of extraordinary intellectual achievements in dreams, as
+Condillac's composition of a part of his _Cours d'Études_. No one would
+maintain that a result of this kind was possible in the total absence of
+intellectual action carefully directed by the will. And something of
+this same control shows itself in all our more fully developed dreams.
+
+One manifestation of this voluntary activity in sleep is to be found in
+those efforts of attention which not unfrequently occur. I have remarked
+that, speaking roughly and in relation to the waking condition, the
+state of sleep is marked by a subjection of the powers of attention to
+the force of the mental images present to consciousness. Yet something
+resembling an exercise of voluntary attention sometimes happens in
+sleep. The intellectual feats just spoken of, unless, indeed, they are
+referred to some mysterious unconscious mental operations, clearly
+involve a measure of volitional guidance. All who dream frequently are
+occasionally aware on awaking of having greatly exercised their
+attention on the images presented to them during sleep. I myself am
+often able to recall an effort to see beautiful objects, which
+threatened to disappear from my field of vision, or to catch faint
+receding tones of preternatural sweetness; and some dreamers allege that
+they are able to retain a recollection of the feeling of strain
+connected with such exercise of attention in sleep.
+
+The main function of this voluntary attention in dream-life is seen in
+the selection of those images which are to pass the threshold of clear
+consciousness. I have already spoken of a selective action brought about
+by the ruling emotion. In this case, the attention is held captive by
+the particular feeling of the moment. Also a selective process goes on
+in the case of the action of those associative dispositions just
+referred to. But in each of these cases the action of selective
+attention is comparatively involuntary, passive, and even unconscious,
+not having anything of the character of a conscious striving to compass
+some end. Besides this comparatively passive play of selective
+attention, there is an active play, in which there is a conscious wish
+to gain an end; in other words, the operation of a definite motive. This
+motive may be described as an intellectual impulse to connect and
+harmonize what is present to the mind. The voluntary kind of selection
+includes and transcends each of the involuntary kinds. It has as its
+result an imitation of that order which is brought about by what I have
+called the associative dispositions, only it consciously aims at this
+result. And it is a process controlled by a feeling, namely, the
+intellectual sentiment of consistency, which is not a mode of emotional
+excitement enthralling the will, but a calm motive, guiding the
+activities of attention. It thus bears somewhat the same relation to the
+emotional selection already spoken of, as dramatic creation bears to
+lyrical composition.
+
+This process of striving to seize some connecting link, or thread of
+order, is illustrated whenever, in waking life, we are suddenly brought
+face to face with an unfamiliar scene. When taken into a factory, we
+strive to arrange the bewildering chaos of visual impressions under some
+scheme, by help of which we are said to understand the scene. So, if on
+entering a room we are plunged in _medias res_ of a lively conversation,
+we strive to find a clue to the discussion. Whenever the meaning of a
+scene is not at once clear, and especially whenever there is an
+appearance of confusion in it, we are conscious of a painful feeling of
+perplexity, which acts as a strong motive to ever-renewed attention.[97]
+
+In touching on this intellectual impulse to connect the disconnected, we
+are, it is plain, approaching the question of the very foundations of
+our intellectual structure. That there is this impulse firmly rooted in
+the mature mind nobody can doubt; and that it manifests itself in early
+life in the child's recurring "Why?" is equally clear. But how we are to
+account for it, whether it is to be viewed as a mere result of the play
+of associated fragments of experience, or as something involved in the
+very process of the association of ideas itself, is a question into
+which I cannot here enter.
+
+What I am here concerned to show is that the search for consistency and
+connection in the manifold impressions of the moment is a deeply rooted
+habit of the mind, and one which is retained in a measure during sleep.
+When, in this state, our minds are invaded by a motley crowd of
+unrelated images, there results a disagreeable sense of confusion; and
+this feeling acts as a motive to the attention to sift out those
+products of the dream-fancy which may be made to cohere. When once the
+foundations of a dream-action are laid, new images must to some extent
+fit in with this; and here there is room for the exercise of a distinct
+impulse to order the chaotic elements of dream-fancy in certain forms.
+The perception of any possible relation between one of the crowd of new
+images ever surging above the level of obscure consciousness, and the
+old group at once serves to detain it. The concentration of attention on
+it, in obedience to this impulse to seek for an intelligible order, at
+once intensifies it and fixes it, incorporating it into the series of
+dream-pictures.
+
+Here is a dream which appears to illustrate this impulse to seek an
+intelligible order in the confused and disorderly. After being occupied
+with correcting the proofs of my volume on _Pessimism_, I dreamt that my
+book was handed to me by my publisher, fully illustrated with coloured
+pictures. The frontispiece represented the fantastic figure of a man
+gesticulating in front of a ship, from which he appeared to have just
+stepped. My publisher told me it was meant for Hamlet, and I immediately
+reflected that this character had been selected as a concrete example of
+the pessimistic tendency. I may add that, on awaking, I was distinctly
+aware of having felt puzzled when dreaming, and of having striven to
+read a meaning into the dream.
+
+The _rationale_ of this dream seems to me to be somewhat as follows. The
+image of the completed volume represented, of course, a recurring
+anticipatory image of waking life. The coloured plates were due probably
+to subjective optical sensations simultaneously excited, which were made
+to fit in (with or without an effort of voluntary attention) with the
+image of the book under the form of illustrations. But this stage of
+coherency did not satisfy the mind, which, still partly confused by the
+incongruity of coloured plates in a philosophic work, looked for a
+closer connection. The image of Hamlet was naturally suggested in
+connection with pessimism. The effort to discover a meaning in the
+pictures led to the fusion of this image with one of the subjective
+spectra, and in this way the idea of a Hamlet frontispiece probably
+arose.
+
+The whole process of dream-construction is clearly illustrated in a
+curious dream recorded by Professor Wundt.[98] Before the house is a
+funeral procession: it is the burial of a friend, who has in reality
+been dead for some time past. The wife of the deceased bids him and an
+acquaintance who happens to be with him go to the other side of the
+street and join the procession. After she has gone away, his companion
+remarks to him, "She only said that because the cholera rages over
+yonder, and she wants to keep this side of the street to herself." Then
+comes an attempt to flee from the region of the cholera. Returning to
+his house, he finds the procession gone, but the street strewn with
+rich nosegays; and he further observes crowds of men who seem to be
+funeral attendants, and who, like himself, are hastening to join the
+procession. These are, oddly enough, dressed in red. When hurrying on,
+it occurs to him that he has forgotten to take a wreath for the coffin.
+Then he wakes up with beating of the heart.
+
+The sources of this dream are, according to Wundt, as follows. First of
+all, he had, on the previous day, met the funeral procession of an
+acquaintance. Again, he had read of cholera breaking out in a certain
+town. Once more, he had talked about the particular lady with this
+friend, who had narrated facts which clearly proved her selfishness. The
+hastening to flee from the infected neighbourhood and to overtake the
+procession was prompted by the sensation of heart-beating. Finally, the
+crowd of red bier-followers, and the profusion of nosegays, owed their
+origin to subjective visual sensations, the "light-chaos" which often
+appears in the dark.
+
+Let us now see for a moment how these various elements may have become
+fused into a connected chain of events. First of all, it is clear that
+this dream is built up on a foundation of a gloomy tone of feeling,
+arising, as it would seem, from an irregularity of the heart's action.
+Secondly, it owes its special structure and its air of a connected
+sequence of events, to those tendencies, passive and active, to order
+the chaotic of which I have been speaking. Let us try to trace this out
+in detail.
+
+To begin with, we may suppose that the image of the procession occupies
+the dreamer's mind. From quite another source the image of the lady
+enters consciousness, bringing with it that of her deceased husband and
+of the friend who has recently been talking about her. These new
+elements adapt themselves to the scene, partly by the passive mechanism
+of associative dispositions, and partly, perhaps, by the activity of
+voluntary selection. Thus, the idea of the lady's husband would
+naturally recall the fact of his death, and this would fall in with the
+pre-existing scene under the form of the idea that he is the person who
+is now being buried. The next step is very interesting. The image of the
+lady is associated with the idea of selfish motives. This would tend to
+suggest a variety of actions, but the one which becomes a factor of the
+dream is that which is specially adapted to the pre-existing
+representations, namely, of the procession on the further side of the
+street, and the cholera (which last, like the image of the funeral, is,
+we may suppose, due to an independent central excitation). That is to
+say, the request of the lady, and its interpretation, are a _resultant_
+of a number of adaptative or assimilative actions, under the sway of a
+strong desire to connect the disconnected, and a lively activity of
+attention. Once more, the feeling of oppression of the heart, and the
+subjective stimulation of the optic nerve, might suggest numberless
+images besides those of anxious flight and of red-clad men and nosegays;
+they suggest these, and not others, in this particular case, because of
+the co-operation of the impulse of consistency, which, setting out with
+the pre-existing mental images, selects from among many tendencies of
+reproduction those which happen to chime in with the scene.
+
+
+_The Nature of Dream-Intelligence._
+
+It must not be supposed that this process of welding together the
+chaotic materials of our dreams is ever carried out with anything like
+the clear rational purpose of which we are conscious when seeking, in
+waking life, to comprehend some bewildering spectacle. At best it is a
+vague longing, and this longing, it may be added, is soon satisfied.
+There is, indeed, something, almost pathetic in the facility with which
+the dreamer's mind can be pacified with the least appearance of a
+connection. Just as a child's importunate "Why?" is often silenced by a
+ridiculous caricature of an explanation, so the dreamer's intelligence
+is freed from its distress by the least semblance of a uniting order.
+
+It thus remains true with respect even to our most coherent dreams, that
+there is a complete suspension, or at least a considerable retardation,
+of the highest operations of judgment and thought; also a great
+enfeeblement, to say the least of it, of those sentiments such as the
+feeling of consistency and the sense of the absurd which are so
+intimately connected with these higher intellectual operations.
+
+In order to illustrate how oddly our seemingly rational dreams
+caricature the operations of waking thought, I may, perhaps, be allowed
+to record two of my own dreams, of which I took careful note at the
+time.
+
+On the first occasion I went "in my dream" to the "Stores" in August,
+and found the place empty. A shopman brought me some large fowls. I
+asked their price, and he answered, "Tenpence a pound." I then asked
+their weight, so as to get an idea of their total cost, and he replied,
+"Forty pounds." Not in the least surprised, I proceeded to calculate
+their cost: 40x10=400÷12=33-1/3. But, oddly enough, I took this quotient
+as pence, just as though I had not already divided by 12, and so made
+the cost of a fowl to be 2s. 9d., which seemed to me a fair enough
+price.
+
+In my second dream I was at Cambridge, among a lot of undergraduates. I
+saw a coach drive up with six horses. Three undergraduates got out of
+the coach. I asked them why they had so many horses, and they said,
+"Because of the luggage." I then said, "The luggage is much more than
+the undergraduates. Can you tell me how to express this in mathematical
+symbols? This is the way: if _x_ is the weight of an undergraduate, then
+_x_ + _x_.n represents the weight of an undergraduate and his luggage
+together." I noticed that this sally was received with evident
+enjoyment.[99]
+
+We may say, then, that the structure of our dreams, equally with the
+fact of their completely illusory character, points to the conclusion
+that during sleep, just as in the moments of illusion in waking life,
+there is a deterioration of our intellectual life. The highest
+intellectual activities answering to the least stable nervous
+connections are impeded, and what of intellect remains corresponds to
+the most deeply organized connections.
+
+In this way, our dream-life touches that childish condition of the
+intelligence which marks the decadence of old age and the encroachments
+of mental disease. The parallelism between dreams and insanity has been
+pointed out by most writers on the subject. Kant observed that the
+madman is a dreamer awake, and more recently Wundt has remarked that,
+when asleep, we "can experience nearly all the phenomena which meet us
+in lunatic asylums." The grotesqueness of the combinations, the lack of
+all judgment as to consistency, fitness, and probability, are common
+characteristics of the short night-dream of the healthy and the long
+day-dream of the insane.[100]
+
+But one great difference marks off the two domains. When dreaming, we
+are still sane, and shall soon prove our sanity. After all, the dream of
+the sleeper is corrected, if not so rapidly as the illusion of the
+healthy waker. As soon as the familiar stimuli of light and sound set
+the peripheral sense-organs in activity, and call back the nervous
+system to its complete round of healthy action, the illusion disappears,
+and we smile at our alarms and agonies, saying, "Behold, it was a
+dream!"
+
+On the practical side, the illusions and hallucinations of sleep must be
+regarded as comparatively harmless. The sleeper, in healthy conditions
+of sleep, ceases to be an agent, and the illusions which enthral his
+brain have no evil practical consequences. They may, no doubt, as we
+shall see in a future chapter, occasionally lead to a subsequent
+confusion of fiction and reality in waking recollection. But with the
+exception of this, their worst effect is probably the lingering sense of
+discomfort which a "nasty dream" sometimes leaves with us, though this
+may be balanced by the reverberations of happy dream-emotions which
+sometimes follow us through the day. And however this be, it is plain
+that any disadvantages thus arising are more than made good by the
+consideration that our liability to these nocturnal illusions is
+connected with the need of that periodic recuperation of the higher
+nervous structures which is a prime condition of a vigorous intellectual
+activity, and so of a triumph over illusion during waking life.
+
+For these reasons dreams may properly be classed with the illusions of
+normal or healthy life, rather than with those of disease. They
+certainly lie nearer this region than the very similar illusions of the
+somnambulist, which with respect to their origin appear to be more
+distinctly connected with a pathological condition of the nervous
+system, and which, with respect to their practical consequences may
+easily prove so disastrous.
+
+
+_After-Dreams._
+
+In concluding this account of dreams, I would call attention to the
+importance of the transition states between sleeping and waking, in
+relation to the production of sense-illusion. And this point may be
+touched on here all the more appropriately, since it helps to bring out
+the close relation between waking and sleeping illusion. The mind does
+not pass suddenly and at a bound from the condition of dream-fancy to
+that of waking perception. I have already had occasion to touch on the
+"hypnagogic state," that condition of somnolence or "sleepiness" in
+which external impressions cease to act, the internal attention is
+relaxed, and the weird imagery of sleep begins to unfold itself. And
+just as there is this anticipation of dream-hallucination in the
+presomnial condition, so there is the survival of it in the postsomnial
+condition. As I have observed, dreams sometimes leave behind them, for
+an appreciable interval after waking, a vivid after-impression, and in
+some cases even the semblance of a sense-perception.
+
+If one reflects how many ghosts and other miraculous apparitions are
+seen at night, and when the mind is in a more or less somnolent
+condition, the idea is forcibly suggested that a good proportion of
+these visions are the _débris_ of dreams. In some cases, indeed, as that
+of Spinoza, already referred to, the hallucination (in Spinoza's case
+that of "a scurvy black Brazilian") is recognized by the subject himself
+as a dream-image.[101] I am indebted to Mr. W.H. Pollock for a fact
+which curiously illustrates the position here adopted. A lady was
+staying at a country house. During the night and immediately on waking
+up she had an apparition of a strange-looking man in mediæval costume,
+a figure by no means agreeable, and which seemed altogether unfamiliar
+to her. The next morning, on rising, she recognized the original of her
+hallucinatory image in a portrait hanging on the wall of her bedroom,
+which must have impressed itself on her brain before the occurrence of
+the apparition, though she had not attended to it. Oddly enough, she now
+learnt for the first time that the house at which she was staying had
+the reputation of being haunted, and by the very same somewhat
+repulsive-looking mediæval personage that had troubled her
+inter-somnolent moments. The case seems to me to be typical with respect
+to the genesis of ghosts, and of the reputation of haunted houses.
+
+       *       *       *       *       *
+
+NOTE.
+
+THE HYPNOTIC CONDITION.
+
+
+I have not in this chapter discussed the relation of dreaming to
+hypnotism, or the state of artificially produced quasi-sleep, because
+the nature of this last is still but very imperfectly understood. In
+this condition, which is induced in a number of ways by keeping the
+attention fixed on some non-exciting object, and by weak continuous and
+monotonous stimulation, as stroking the skin, the patient can be made to
+act conformably to the verbal or other suggestion of the operator, or to
+the bodily position which he is made to assume. Thus, for example, if a
+glass containing ink is given to him, with the command to drink, he
+proceeds to drink. If his hands are folded, he proceeds to act as if he
+were in church, and so on.
+
+Braid, the writer who did so much to get at the facts of hypnotism, and
+Dr. Carpenter who has helped to make known Braid's careful researches,
+regard the actions of the hypnotized subject as analogous to ideomotor
+movements; that is to say, the movements due to the tendency of an idea
+to act itself out apart from volition. On the other hand, one of the
+latest inquirers into the subject, Professor Heidenhain, of Breslau,
+appears to regard these actions as the outcome of "unconscious
+perceptions" (_Animal Magnetism_, English translation, p. 43, etc.).
+
+In the absence of certain knowledge, it seems allowable to argue from
+the analogy of natural sleep that the actions of the hypnotized patient
+are accompanied with the lower forms of consciousness, including
+sensation and perception, and that they involve dream-like
+hallucinations respecting the external circumstances of the moment.
+Regarding them in this light, the points of resemblance between
+hypnotism and dreaming are numerous and striking. Thus, Dr. Heidenhain
+tells us that the threshold or liminal value of stimulation is lowered
+just as in ordinary sleep sense-activity as a whole is lowered.
+According to Professor Weinhold, the hypnotic condition begins in a
+gradual loss of taste, touch, and the sense of temperature; then sight
+is gradually impaired, while hearing remains throughout the least
+interfered with.[102] In this way, the mind of the patient is largely
+cut off from the external world, as in sleep, and the power of
+orientation is lost. Moreover, there are all the conditions present,
+both positive and negative, for the hallucinatory transformation of
+mental images into percepts just as in natural sleep. Thus, the higher
+centres connected with the operations of reflection and reasoning are
+thrown _hors de combat_ or, as Dr. Heidenhain has it, "inhibited."
+
+The condition of hypnotism is marked off from that of natural sleep,
+first of all, by the fact that the accompanying hallucinations are
+wholly due to external suggestion (including the effects of bodily
+posture). Dreams may, as we have seen, be very faintly modified by
+external influences, but during sleep there is nothing answering to the
+perfect control which the operator exercises over the hypnotized
+subject. The largest quantity of our "dream-stuff" comes, as we have
+seen, from within and not from without the organism. And this fact
+accounts for the chief characteristic difference between the natural and
+the hypnotic dream. The former is complex, consisting of crowds of
+images, and continually changing: the latter is simple, limited, and
+persistent. As Braid remarks, the peculiarity of hypnotism is that the
+attention is concentrated on a remarkably narrow field of mental images
+and ideas. So long as a particular bodily posture is assumed, so long
+does the corresponding illusion endure. One result of this, in
+connection with that impairing of sensibility already referred to, is
+the scope for a curious overriding of sense-impressions by the dominant
+illusory percept, a process that we have seen illustrated in the active
+sense-illusions of waking life. Thus, if salt water is tasted and the
+patient is _told_ that it is beer, he complains that it is sour.
+
+In being thus in a certain rapport, though so limited and unintelligent
+a rapport, with the external world, the mind of the hypnotized patient
+would appear to be nearer the condition of waking illusion than is the
+mind of the dreamer. It must be remembered, however, and this is the
+second point of difference between dreaming and hypnotism, that the
+hypnotized subject tends _to act out_ his hallucinations. His
+quasi-percepts are wont to transform themselves into actions with a
+degree of force of which we see no traces in ordinary sleep. Why there
+should be this greater activity of the motor organs in the one condition
+than in the other, seems to be a point as yet unexplained. All
+sense-impressions and percepts are doubtless accompanied by some degree
+of impulse to movement, though, for some reason or another, in natural
+and healthy sleep these impulses are restricted to the stage of faint
+nascent stirrings of motor activity which hardly betray themselves
+externally. This difference, involving a great difference in the
+possible practical consequences of the two conditions of natural and
+hypnotic sleep, clearly serves to bring the latter condition nearer to
+that of insanity than the former condition is brought. A strong
+susceptibility to the hypnotic influence, such as Dr. Heidenhain
+describes, might, indeed, easily prove a very serious want of
+"adaptation of internal to external relations," whereas a tendency to
+dreaming would hardly prove a maladaptation at all.
+
+
+
+
+CHAPTER VIII.
+
+ILLUSIONS OF INTROSPECTION.
+
+
+We have now, perhaps, sufficiently reviewed sense-illusions, both of
+waking life and of sleep. And having roughly classified them according
+to their structure and origin, we are ready to go forwards and inquire
+whether the theory thus reached can be applied to other forms of
+illusory error. And here we are compelled to inquire at the outset if
+anything analogous to sense-illusion is to be found in that other great
+region of presentative cognition usually marked off from external
+perception as internal perception, self-reflection, or introspection.
+
+
+_Illusions of Introspection defined._
+
+This inquiry naturally sets out with the question: What is meant by
+introspection? This cannot be better defined, perhaps, than by saying
+that it is the mind's immediate reflective cognition of its own states
+as such.
+
+In one sense, of course, everything we know may be called a mental
+state, actual or imagined. Thus, a sense-impression is known, exactly
+like any other feeling of the mind, as a mental phenomenon or mental
+modification. Yet we do not usually speak of introspectively
+recognizing a sensation. Our sense-impressions are marked off from all
+other feelings by having an objective character, that is to say, an
+immediate relation to the external world, so that in attending to one of
+them our minds pass away from themselves in what Professor Bain calls
+the attitude of objective regard. Introspection is confined to feelings
+which want this intimate connection with the external region, and
+includes sensation only so far as it is viewed apart from external
+objects and on its mental side as a feeling, a process which is next to
+impossible where the sensation has little emotional colour, as in the
+case of an ordinary sensation of sight or of articulate sound.
+
+This being so, errors of introspection, supposing such to be found, will
+in the main be sufficiently distinguished from those of perception. Even
+an hallucination of sense, whether setting out from a subjective
+sensation or not, always contains the semblance of a sense-impression,
+and so would not be correctly classed with errors of introspection.
+
+Just as introspection must be marked off from perception, so must it be
+distinguished from memory. It may be contended that, strictly speaking,
+all introspection is retrospection, since even in attending to a present
+feeling the mind is reflectively representing to itself the immediately
+preceding momentary experience of that feeling. Yet the adoption of this
+view does not hinder us from drawing a broad distinction between acts of
+introspection and acts of memory. Introspection must be regarded as
+confined to the knowledge of immediately antecedent mental states with
+reference to which, no error of memory can be supposed to arise.
+
+It follows from this that an illusion of introspection could only be
+found in connection with the apprehension of present or immediately
+antecedent mental states. On the other hand, any illusions connected
+with the consciousness of personal continuity and identity would fall
+rather under the class of mnemonic than that of introspective error.
+
+Once more, introspection must be carefully distinguished from what I
+have called belief. Some of our beliefs may be found to grow out of and
+be compounded of a number of introspections. Thus, my conception of my
+own character, or my psychological conception of mind as a whole, may be
+seen to arise by a combination of the results of a number of acts of
+introspection. Yet, supposing this to be so, we must still distinguish
+between the single presentative act of introspection and the
+representative belief growing out of it.
+
+It follows from this that, though an error of the latter sort might
+conceivably have its origin in one of the former; though, for example, a
+man's illusory opinion of himself might be found to involve errors of
+introspection, yet the two kinds of illusion would be sufficiently
+unlike. The latter would be a simple presentative error, the former a
+compound representative error.
+
+Finally, in order to complete this preliminary demarcation of our
+subject-matter, it is necessary to distinguish between an introspection
+(apparent or real) of a feeling or idea, and a process of inference
+based on this feeling. The term introspective knowledge must, it is
+plain, be confined to what is or appears to be in the mind at the moment
+of inspection.
+
+By observing this distinction, we are in a position to mark off an
+_illusion_ of introspection from a _fallacy_ of introspection. The
+former differs from the latter in the absence of anything like a
+conscious process of inference. Thus, if we suppose that the derivation
+by Descartes of the fact of the existence of God from his possession of
+the idea to be erroneous, such a consciously performed act of reasoning
+would constitute a fallacy rather than an illusion of introspection.
+
+We may, then, roughly define an illusion of introspection as an error
+involved in the apprehension of the contents of the mind at any moment.
+If we mistake the quality or degree of a feeling or the structure of a
+complex mass of feeling, or if we confuse what is actually present to
+the mind with some inference based on this, we may be said to fall into
+an illusion of introspection.
+
+But here the question will certainly be raised: How can we conceive the
+mind erring as to the nature of its present contents; and what is to
+determine, if not my immediate act of introspection, what is present in
+my mind at any moment? Indeed, to raise the possibility of error in
+introspection seems to do away with the certainty of presentative
+knowledge.
+
+If, however, the reader will recall what was said in an earlier chapter
+about the possibility of error in recognizing the quality of a
+sense-impression, he will be prepared for a similar possibility here.
+What we are accustomed to call a purely presentative cognition is, in
+truth, partly representative. A feeling as pure feeling is not known; it
+is only known when it is distinguished, as to quality or degree, and so
+classed or brought under some representation of a kind or description of
+feeling, as acute, painful, and so on. The accurate recognition of an
+impression of colour depends, as we have seen, on this process of
+classing being correctly performed. Similarly, the recognition of
+internal feelings implies the presence of the appropriate or
+corresponding class-representation. Accordingly, if it is possible for a
+wrong representation to get substituted for the right one, there seems
+to be an opening for error.
+
+Any error that would thus arise can, of course, only be determined as
+such in relation to some other act of introspection of the same mind. In
+matters of internal perception other minds cannot directly assist us in
+correcting error as they can in the case of external perception, though,
+as we shall see by-and-by, they may do so indirectly. The standard of
+reality directly applicable to introspective cognition is plainly what
+the individual mind recognizes at its best moments, when the processes
+of attention and classifying are accurately performed, and the
+representation may be regarded with certainty as answering to the
+feeling. In other words, in the sphere of internal, as in that of
+external experience, the criterion of reality is the average and
+perfect, as distinguished from the particular variable and imperfect act
+of cognition.
+
+We see, then, that error in the process of introspection is at least
+conceivable. And now let us examine this process a little further, in
+order to find out what probabilities of error attach to it.
+
+To begin with, then, an act of introspection, to be complete, clearly
+involves the apprehension of an internal feeling or idea as something
+mental and marked off from the region of external experience. This
+distinct recognition of internal states of mind as such, in opposition
+to external impressions, is by no means easy, but presupposes a certain
+degree of intellectual culture, and a measure of the power of abstract
+attention.
+
+
+_Confusion of Internal and External Experience._
+
+Accordingly, we find that where this is wanting there is a manifest
+disposition to translate internal feelings into terms of external
+impressions. In this way there may arise a slight amount of habitual and
+approximately constant error. Not that the process approaches to one of
+hallucination; but only that the internal feelings are intuited as
+having a cause or origin analogous to that of sense-impressions. Thus to
+the uncultivated mind a sudden thought seems like an audible
+announcement from without. The superstitious man talks of being led by
+some good or evil spirit when new ideas arise in his mind or new
+resolutions shape themselves. To the simple intelligence of the boor
+every thought presents itself as an analogue of an audible voice, and he
+commonly describes his rough musings as saying this and that to himself.
+And this, mode of viewing the matter is reflected even, in the language
+of cultivated persons. Thus we say, "The idea struck me," or "was borne
+in on me," "I was forced to do so and so," and so on, and in this
+manner we tend to assimilate internal to external mental phenomena.
+
+Much the same thing shows itself in our customary modes of describing
+our internal feelings of pleasure and pain. When a man in a state of
+mental depression speaks of having "a load" on his mind it is evident
+that he is interpreting a mental by help of an analogy to a bodily
+feeling. Similarly, when we talk of the mind being torn by doubt or worn
+by anxiety. It would seem as though we tended mechanically to translate
+mental pleasures and pains into the language of bodily sensations.
+
+The explanation of this deeply rooted tendency to a slightly illusory
+view of our mental states is, I think, an easy one. For one thing, it
+follows from the relation of the mental image to the sense-impression
+that we should tend to assimilate the former to the latter as to its
+nature and origin. This would account for the common habit of regarding
+thoughts, which are of course accompanied by representatives of their
+verbal symbols, as internal voices, a habit which is probably especially
+characteristic of the child and the uncivilized man, as we have found it
+to be characteristic of the insane.
+
+Another reason, however, must be sought for the habit of assimilating
+internal feelings to external sensations. If language has been evolved
+as an incident of social life, at once one of its effects and its
+causes, it would seem to follow that it must have first shaped Itself to
+the needs of expressing these common objective experiences which we
+receive by way of our senses. Our habitual modes of thought, limited as
+they are by language, retain traces of this origin. We cannot conceive
+any mental process except by some vague analogy to a physical process.
+In other words, we can even now only think with perfect clearness when
+we are concerned with some object of common cognition. Thus, the sphere
+of external sensation and of physical agencies furnishes us with the one
+type of thinkable thing or object of thought, and we habitually view
+subjective mental states as analogues of these.
+
+Still, it may be said that these slight nascent errors are hardly worth
+naming, and the question would still appear to recur whether there are
+other fully developed errors deserving to rank along with illusions of
+sense. Do we, it may be asked, ever actually mistake the quality,
+degree, or structure of our internal feelings in the manner hinted
+above, and if so, what is the range of such error? In order to
+appreciate the risks of such error, let us compare the process of
+self-observation with that of external perception with respect to the
+difficulties in the way of accurate presentative knowledge.
+
+
+_Misreading of Internal Feelings._
+
+First of all, it is noteworthy that a state of consciousness at any one
+moment is an exceedingly complex thing. It is made up of a mass of
+feelings and active impulses which often combine and blend in a most
+inextricable way. External sensations come in groups, too, but as a rule
+they do not fuse in apparently simple wholes as our internal feelings
+often do. The very possibility of perception depends on a clear
+discrimination of sense-elements, for example, the several sensations
+of colour obtained by the stimulation of different parts of the
+retina.[103] But no such clearly defined mosaic of feelings presents
+itself in the internal region: one element overlaps and partly loses
+itself in another, and subjective analysis is often an exceedingly
+difficult matter. Our consciousness is thus a closely woven texture in
+which the mental eye often fails to trace the several threads or
+strands. Moreover, there is the fact that many of these ingredients are
+exceedingly shadowy, belonging to that obscure region of
+sub-consciousness which it is so hard to penetrate with the light of
+discriminative attention. This remark applies with particular force to
+that mass of organic feelings which constitutes what is known as
+coenæsthesis; or vital sense.
+
+While, to speak figuratively, the minute anatomy of consciousness is
+thus difficult with respect to longitudinal sections of the mental
+column, it is no less difficult with respect to transverse sections.
+Under ordinary circumstances, external impressions persist so that they
+can be transfixed by a deliberate act of attention, and objects rarely
+flit over the external scene so rapidly as to allow us no time for a
+careful recognition of the impression. Not so in the case of the
+internal region of mind. The composite states of consciousness just
+described never remain perfectly uniform for the shortest conceivable
+duration. They change continually, just as the contents of the
+kaleidoscope vary with every shake of the instrument. Thus, one shade
+of feeling runs into another in such a way that it is often impossible
+to detect its exact quality; and even when the character of the feeling
+does not change, its intensity is undergoing alterations so that an
+accurate observation of its quantity is impracticable. Also, in this
+unstable shifting internal scene features may appear for a duration too
+short to allow of close recognition. In this way it happens that we
+cannot sharply divide the feeling of the moment from its antecedents and
+its consequents.
+
+If, now, we take these facts in connection with what has been said above
+respecting the nature of the process of introspection, the probability
+of error will be made sufficiently clear. To transfix any particular
+feeling of the moment, to selectively attend to it, and to bring it
+under the proper representation, is an operation that requires time, a
+time which, though short, is longer than the fugitive character of so
+much of our internal mental life allows. From all of which it would
+appear to follow that it must be very easy to overlook, confuse, and
+transform, both as to quality and as to quantity, the actual ingredients
+of our internal consciousness.
+
+From these sources there spring a number of small errors of
+introspection which, to distinguish them from others to be spoken of
+presently, may be called passive. These would include all errors in
+detecting what is in consciousness due to the intricacies of the
+phenomena, and not aided by any strong basis. For example, a mental
+state may fail to disclose its component parts to introspective
+attention. Thus, a motive may enter into our action which is so
+entangled with other feelings as to escape our notice. The fainter the
+feeling the greater the difficulty of detaching it and inspecting it in
+isolation. Again, an error of introspection may have its ground in the
+fugitive character of a feeling. If, for example, a man is asked whether
+a rapid action was a voluntary one, he may in retrospection easily
+imagine that it was not so, when as a matter of fact the action was
+preceded by a momentary volition. When a person exclaims, "I did a thing
+inadvertently or mechanically," it often means that he did not note the
+motive underlying the action. Such transitory feelings which cannot at
+the moment be seized by an act of attention are pretty certain to
+disappear at once, leaving not even a temporary trace in consciousness.
+
+We will now pass to the consideration of other illusions of
+introspection more analogous to what I have called the active illusions
+of perception. In our examination of these we found that a pure
+representation may under certain circumstances simulate the appearance
+of a presentation, that a mental image may approximate to a
+sense-impression. In the case of the internal feelings this liability
+shows itself in a still more striking form.
+
+The higher feelings or emotions are distinguished from the simple
+sense-feelings in being largely representative. Thus, a feeling of
+contentment at any moment, though no doubt conditioned by the bodily
+state and the character of the organic sensations or coenæsthesis,
+commonly depends for the most part on intellectual representations of
+external circumstances or relations, and may be called an ideal
+foretaste of actual satisfactions, such as the pleasures of success, of
+companionship, and so on. This being so, it is easy for imagination to
+call up a semblance of these higher feelings. Since they depend largely
+on representation, a mere act of representation may suffice to excite a
+degree of the feeling hardly distinguishable from the actual one. Thus,
+to imagine myself as contented is really to see myself at the moment as
+actually contented. Again, the actor, though, as we shall see by-and-by,
+he does not feel all that the spectator is apt to attribute to him,
+tends, when vividly representing to himself a particular shade of
+feeling, to regard himself as actually feeling in this way. Thus, it is
+said of Garrick, that when acting Richard III., he felt himself for the
+moment to be a villain.
+
+We should expect from all this that in the act of introspection the mind
+is apt, within certain limits, to find what it is prepared to find. And
+since there is in these acts often a distinct wish to detect some
+particular feeling, we can see how easy it must be for a man through
+bias and a wrong focussing of the attention to deceive himself up to a
+certain point with respect to the actual contents of his mind.
+
+Let us examine one of these active illusions a little more fully. It
+would at first sight seem to be a perfectly simple thing to determine at
+any given moment whether we are enjoying ourselves, whether our
+emotional condition rises above the pleasure-threshold or point of
+indifference and takes on a positive hue of the agreeable or
+pleasurable. Yet there is good reason for supposing that people not
+unfrequently deceive themselves on this matter. It is, perhaps, hardly
+an exaggeration to say that most of us are capable of imagining that we
+are having enjoyment when we conform to the temporary fashion of social
+amusement. It has been cynically observed that people go into society
+less in order to be happy than to seem so, and one may add that in this
+semblance of enjoyment they may, provided they are not _blasé_, deceive
+themselves as well as others. The expectation of enjoyment, the
+knowledge that the occasion is intended to bring about this result, the
+recognition of the external signs of enjoyment in others--all this may
+serve to blind a man in the earlier stages of social amusement to his
+actual mental condition.
+
+If we look closely into this variety of illusion, we shall see that it
+is very similar in its structure and origin to that kind of erroneous
+perception which arises from inattention to the actual impression of the
+moment under the influence of a strong expectation of something
+different. The representation of ourselves as entertained dislodges from
+our internal field of vision our actual condition, relegating this to
+the region of obscure consciousness. Could we for a moment get rid of
+this representation and look at the real feelings of the time, we should
+become aware of our error; and it is possible that the process of
+becoming _blasé_ involves a waking up to a good deal of illusion of the
+kind.
+
+Just as we can thus deceive ourselves within certain limits as to our
+emotional condition, so we can mistake the real nature of our
+intellectual condition. Thus, when an idea is particularly grateful to
+our minds, we may easily imagine that we believe it, when in point of
+fact all the time there is a sub-conscious process of criticism going
+on, which if we attended to it for a moment would amount to a distinct
+act of disbelief. Some persons appear to be capable of going on
+habitually practising this petty deceit on themselves, that is to say,
+imagining they believe what in fact they are strongly inclined to doubt.
+Indeed, this remark applies to all the grateful illusions respecting
+ourselves and others, which will have to be discussed by-and-by. The
+impulse to hold to the illusion in spite of critical reflection,
+involves the further introspective illusion of taking a state of doubt
+for one of assurance. Thus, the weak, flattered man or woman manages to
+keep up a sort of fictitious belief in the truth of the words which are
+so pleasant to the ear.
+
+It is plain that the external conditions of life impose on the
+individual certain habits of feeling which often conflict with his
+personal propensities. As a member of society he has a powerful motive
+to attribute certain feelings to himself, and this motive acts as a bias
+in disturbing his vision of what is actually in his mind. While this
+holds good of lighter matters, as that of enjoyment just referred to, it
+applies still more to graver matters. Thus, for example, a man may
+easily persuade himself that he feels a proper sentiment of indignation
+against a perpetrator of some mean or cruel act, when as a matter of
+fact his feeling is much more one of compassion for the previously liked
+offender. In this way we impose on ourselves, disguising our real
+sentiments by a thin veil of make-believe.
+
+So far I have spoken of an illusion of introspection as analogous to
+the slight misapprehensions of sense-impression which were touched on in
+connection with illusions of sense (Chapter III.). It is to be observed,
+however, that the confusing of elements of consciousness, which is so
+prominent a factor in introspective illusion, involves a species of
+error closely analogous to a complete illusion of perception, that is to
+say, one which involves a misinterpretation of a sense-impression.
+
+This variety of illusion is illustrated in the case in which a present
+feeling or thought is confounded with some inference based on it. For
+example, a present thought may, through forgetfulness, be regarded as a
+new discovery. Its originality appears to be immediately made known in
+the very freshness which characterizes it. Every author probably has
+undergone the experience of finding that ideas which started up to his
+mind as fresh creations, were unconscious reminiscences of his own or of
+somebody else's ideas.
+
+In the case of present emotional states this liability to confuse the
+present and the past is far greater. Here there is something hardly
+distinguishable from an active illusion of sense-perception. In this
+condition of mind a man often says that he has an "intuition" of
+something supposed to be immediately given in the feeling itself. For
+instance, one whose mind is thrilled by the pulsation of a new joy
+exclaims, "This is the happiest moment of my life," and the assurance
+seems to be contained in the very intensity of the feeling itself. Of
+course, cool reflection will tell him that what he affirms is merely a
+belief, the accuracy of which presupposes processes of recollection and
+judgment, but to the man's mind at the moment the supremacy of this
+particular joy is immediately intuited. And so with the assurance that
+the present feeling, for example of love, is undying, that it is equal
+to the most severe trials, and so on. A man is said to _feel_ at the
+moment that it is so, though as the facts believed have reference to
+absent circumstances and events, it is plain that the knowledge is by no
+means intuitive.
+
+At such times our minds are in a state of pure feeling: intellectual
+discrimination and comparison are no longer possible. In this way our
+emotions in the moments of their greatest intensity carry away our
+intellects with them, confusing the region of pure imagination with that
+of truth and certainty, and even the narrow domain of the present with
+the vast domain of the past and future. In this condition differences of
+present and future may be said to disappear and the energy of the
+emotion to constitute an immediate assurance of its existence
+absolutely.[104]
+
+The great region for the illustration of these active illusions is that
+of the moral and religious life. With respect to our real motives, our
+dominant aspirations, and our highest emotional experiences, we are
+greatly liable to deceive ourselves. The moralist and the theologian
+have clearly recognized the possibilities of self-deception in matters
+of feeling and impulse. To them it is no mystery that the human heart
+should mistake the fictitious for the real, the momentary and evanescent
+for the abiding. And they have recognized, too, the double bias in these
+errors, namely, the powerful disposition to exaggerate the intensity and
+persistence of a present feeling on the one hand, and on the other hand
+to take a mere wish to feel in a particular way for the actual
+possession of the feeling.
+
+
+_Philosophic Illusions._
+
+The opinion of theologians respecting the nature of moral introspection
+presents a singular contrast to that entertained by some philosophers as
+to the nature of self-consciousness. It is supposed by many of these
+that in interrogating their internal consciousness they are lifted above
+all risk of error. The "deliverance of consciousness" is to them
+something bearing the seal of a supreme authority, and must not be
+called in question. And so they make an appeal to individual
+consciousness a final resort in all matters of philosophical dispute.
+
+Now, on the face of it, it does not seem probable that this operation
+should have an immunity from all liability to error. For the matters
+respecting which we are directed to introspect ourselves, are the most
+subtle and complex things of our intellectual and emotional life. And
+some of these philosophers even go so far as to affirm that the plain
+man is quite equal to the niceties of this process.
+
+It has been brought as a charge against some of these same philosophers
+that they have based certain of their doctrines on errors of
+introspection. This charge must, of course, be received with some sort
+of suspicion here, since it has been brought forward by avowed disciples
+of an opposite philosophic school. Nevertheless, as there is from our
+present disinterested and purely scientific point of view a presumption
+that philosophers like other men are fallible, and since it is certain
+that philosophical introspection does not materially differ from other
+kinds, it seems permissible just to glance at some of these alleged
+illusions in relation to other and more vulgar forms. Further reference
+to them will be made at the end of our study.
+
+These so-called philosophical illusions will be found, like the vulgar
+ones just spoken of, to illustrate the distinction drawn between passive
+and active illusions. That is to say, the alleged misreading of
+individual consciousness would result now from a confusion of distinct
+elements, including wrong suggestion, due to the intricacies of the
+phenomena, now from a powerful predisposition to read something into the
+phenomena.
+
+A kind of illusion in which the passive element seems most conspicuous
+would be the error into which the interrogator of the individual
+consciousness is said to fall respecting simple unanalyzable states of
+mind. On the face of it, it is not likely that a mere inward glance at
+the tangle of conscious states should suffice to determine what is such
+a perfectly simple mental phenomenon. Accordingly, when a writer
+declares that an act of introspection demonstrates the simple
+unanalyzable character of such a feeling as the sentiment of beauty or
+that of moral approval, the opponent of this view clearly has some show
+of argument for saying that this simplicity may be altogether illusory
+and due to the absence of a perfect act of attention. Similarly, when it
+is said that the idea of space contains no representations of muscular
+sensation, the statement may clearly arise from the want of a
+sufficiently careful kind of introspective analysis.[105]
+
+In most cases of these alleged philosophical errors, however, the active
+and passive factors seem to combine. There are certain intricacies in
+the mental phenomenon itself favouring the chances of error, and there
+are independent predispositions leading the mind to look at the
+phenomenon in a wrong way. This seems to apply to the famous declaration
+of a certain school of thinkers that by an act of introspection we can
+intuit the fact of liberty, that is to say, a power of spontaneous
+determination of action superior to and regulative of the influence of
+motives. It may be plausibly contended that this idea arises partly
+from a mixing up of facts of present consciousness with inferences from
+them, and partly from a natural predisposition of the mind to invest
+itself with this supreme power of absolute origination.[106]
+
+In a similar way, it might be contended that other famous philosophic
+dicta are founded on a process of erroneous introspection of subjective
+mental states. In some cases, indeed, it seems a plausible explanation
+to regard these illusions as mere survivals in attenuated shadowy form
+of grosser popular illusions. But this is not yet the time to enter on
+these, which, moreover, hardly fall perhaps under our definition of an
+illusion of introspection.
+
+
+_Value of the Introspective Method._
+
+In drawing up this rough sketch of the illusions of introspection, I
+have had no practical object in view. I have tried to look at the facts
+as they are apart from any conclusions to be drawn from them. The
+question how far the liability to error in any region of inquiry
+vitiates the whole process is a difficult one; and the question whether
+the illusions to which we are subject in introspection materially affect
+the value of self-knowledge as a whole and consequently of the
+introspective method in psychology, as many affirm, is too subtle a one
+to be fully treated now. All that I shall attempt here is to show that
+it does not do this any more than the risk of sense-illusion can be said
+materially to affect the value of external observation.
+
+It is to be noted first of all that the errors of introspection are much
+more limited than those of sense-perception. They broadly answer to the
+slight errors connected with the discrimination and recognition of the
+sense-impression. There is nothing answering to a complete hallucination
+in the sphere of the inner mental life. It follows, too, from what has
+been said above, that the amount of active error in introspection is
+insignificant, since the representation of a feeling or belief is so
+very similar to the actual experience of it.
+
+In brief, the errors of introspection, though numerous, are all too
+slight to render the process of introspection as a whole unsound and
+untrustworthy. Though, as we have seen, it involves, strictly speaking,
+an ingredient of representation, this fact does not do away with the
+broad distinction between presentative and representative cognition.
+Introspection is presentative in the sense that the reality constituting
+the object of cognition, the mind's present feeling, is as directly
+present to the knowing mind as anything can be conceived to be. It may
+be added that the power of introspection is a comparatively new
+acquisition of the human race, and that, as it improves, the amount of
+error connected with its operation may reasonably be expected to become
+infinitesimal.
+
+It is often supposed by those who undervalue the introspective method in
+psychology that there is a special difficulty in the detection of error
+in introspection, owing to the fact that the object of inspection is
+something individual and private, and not open to common scrutiny as the
+object of external perception. Yet, while allowing a certain force to
+this objection I would point out, first of all, that even in
+sense-perception, what the individual mind is immediately certain of is
+its own sensations. The relatively perfect certainty which finally
+attaches to the presentative side of sense-perception is precisely that
+which finally attaches to the results of introspection.
+
+In the second place, it may be said that the contrast between the inner
+and the outer experience is much less than it seems. In many cases our
+emotions are the direct result of a common external cause, and even when
+they are not thus attached to some present external circumstance, we are
+able, it is admitted, by the use of language, roughly to compare our
+individual feelings. And such comparison is continually bringing to
+light the fact that there is a continuity in our mental structure, that
+our highest thoughts and emotions lead us back to our common
+sense-impressions, and that consequently, in spite of all individual
+differences of temperament and mental organization, our inner experience
+is in all its larger features a common experience.
+
+I may add that this supposition of the common nature of our internal
+experience, as a whole, not only underlies the science of psychology,
+but is implied in the very process of detecting and correcting errors of
+introspection. I do not mean that in matters of feeling "authority" is
+to override "private judgment." Our last resort with respect to things
+of the mind is, as I have said, that of careful self-inspection. And the
+progress of psychology and the correction of illusion proceed by means
+of an ever-improving exercise of the introspective faculty. Yet such
+individual inspection can at least be _guided_ by the results of others'
+similar inspection, and should be so guided as soon as a general
+consensus in matters of internal experience is fairly made out. In point
+of fact, the preceding discussion of illusions of introspection has
+plainly rested on the sufficiently verified assumption that the calmest
+and most efficient kind of introspection, in bringing to light what is
+permanent as compared with what is variable in the individual cognition,
+points in the direction of a common body of introspected fact.
+
+
+
+
+CHAPTER IX.
+
+OTHER QUASI-PRESENTATIVE ILLUSIONS: ERRORS OF INSIGHT.
+
+
+Besides the perception of external objects, and the inspection of our
+internal mental states, there are other forms of quasi-presentative
+cognition which need to be touched on here, inasmuch as they are
+sometimes erroneous and illusory.
+
+In the last chapter I alluded to the fact that emotion may arise as the
+immediate accompaniment of a sense-impression. When this is the case
+there is a disposition to read into the external object a quality
+answering to the emotion, just as there is a disposition to ascribe to
+objects qualities of heat and cold answering to the sensations thus
+called. And such a reference of an emotional result to an external
+exciting cause approximates in character to an immediate intuition. The
+cognition of the quality is instantaneous, and quite free from any
+admixture of conscious inference. Accordingly, we have to inquire into
+the illusory forms of such intuition, if such there be.
+
+
+_Æsthetic Intuition._
+
+Conspicuous among these quasi-presentative emotional cognitions is
+æsthetic intuition, that is to say, the perception of an object as
+beautiful. It is not necessary here to raise the question whether there
+is, strictly speaking, any quality in things answering to the sentiment
+of beauty in our minds: this is a philosophical and not a psychological
+question, and turns on the further question, what we mean by object. All
+that we need to assume here is that there are certain aspects of
+external things, certain relations of form, together with a power of
+exciting certain pleasurable ideas in the spectator's mind, which are
+commonly recognized as the cause of the emotion of beauty, and indeed
+regarded as constituting the embodiments of the objective quality,
+beauty. Æsthetic intuition thus clearly implies the immediate assurance
+of the existence of a common source of æsthetic delight, a source bound
+up with an object of common sense-perception. And so we may say that to
+call a thing beautiful is more or less distinctly to recognize it as a
+cause of a present emotion, and to attribute to it a power of raising a
+kindred emotion in other minds.
+
+
+_Æsthetic Illusion._
+
+According to this view of the matter, an illusion of æsthetic intuition
+would arise whenever this power of affecting a number of minds
+pleasurably is wrongly attributed, by an act of "intuition," to an
+object of sense-perception, on the ground of a present personal
+feeling.
+
+Now, this error is by no means unfrequent. Our delight in viewing
+external things, though agreeing up to a certain point, does not agree
+throughout. It is a trite remark that there is a large individual
+factor, a considerable "personal equation," in matters of taste, as in
+other matters. Permanent differences of natural sensibility, of
+experience, of intellectual habits, and so on, make an object
+æsthetically impressive and valuable to one man and not to another. Yet
+these differences tend to be overlooked. The individual mind, filled
+with delight at some spectacle, automatically projects its feeling
+outwards in the shape of a cause of a common sentiment. And the force of
+this impulse cannot be altogether explained as the effect of past
+experiences and of association. It seems to involve, in addition, the
+play of social instincts, the impulse of the individual mind to connect
+itself in sympathy with the collective mind.
+
+Here, as in the other varieties of illusion already treated of, we may
+distinguish between a passive and an active side; only in this case the
+passive side must not be taken as corresponding to any common
+suggestions of the object, as in the case of perception proper. So far
+as an illusion of æsthetic intuition may be considered as passive, it
+must be due to the effect of circumscribed individual associations with
+the object.
+
+All agree that what is called beauty consists, to a considerable extent,
+of a power of awaking pleasant suggestions, but in order that these
+should constitute a ground of æsthetic value, they must be common,
+participated in by all, or at least by an indefinite number. This will
+be the case when the association rests on our common every-day
+experiences, and our common knowledge of things, as in the case of the
+peaceful beauty of an ascending curl of blue smoke in a woody landscape,
+or the awful beauty of a lofty precipice. On the other hand, when the
+experience and recollections, which are the source of the pleasure, are
+restricted and accidental, any attribution of objective worth is
+illusory. Thus, the ascription of beauty to one's native village, to
+one's beloved friends, and so on, in so far as it carries the conviction
+of objective worth, may imply a confusion of the individual with the
+common experience.
+
+The active side of this species of illusions would be illustrated in
+every instance of ascribing beauty to objects which is due, in a
+considerable measure at least, to some pre-existing disposition in the
+mind, whether permanent or temporary. A man brings his peculiar habits
+of thought and feeling to the contemplation of objects, and the æsthetic
+impression produced is coloured by these predispositions. Thus, a person
+of a sad and gloomy cast of mind will be disposed to see a sombre beauty
+where other eyes see nothing of the kind. And then there are all the
+effects of temporary conditions of the imagination and the feelings.
+Thus, the individual mind may be focussed in a certain way through the
+suggestion of another. People not seldom see a thing to be beautiful
+because they are told that it is so. It might not be well to inquire too
+curiously how many of the frequenters of the annual art exhibitions use
+their own eyes in framing their æsthetic judgments. Or the temporary
+predisposition may reside in a purely personal feeling or desire
+uppermost at the time. Our enjoyment of nature or of art is coloured by
+our temporary mood. There are moments of exceptional mental
+exhilaration, when even a commonplace scene will excite an appreciable
+kind of admiration. Or there may be a strong wish to find a thing
+beautiful begotten of another feeling. Thus, a lover desires to find
+beauty in his mistress; or, having found it in her face and form,
+desires to find a harmonious beauty in her mind. In these different ways
+temporary accidents of personal feeling and imagination enter into and
+determine our æsthetic intuition, making it deviate from the common
+standard. This kind of error may even approximate in character to an
+hallucination of sense when there is nothing answering to a common
+source of æsthetic pleasure. Thus, the fond mother, through the very
+force of her affection, will construct a beauty in her child, which for
+others is altogether non-existent.
+
+What applies to the perception of beauty in the narrow sense will apply
+to all other modes of æsthetic intuition, as that of the sublime and the
+ludicrous, and the recognition of the opposite of beauty or the ugly. In
+like manner, it will apply to moral intuition in so far as it is an
+instantaneous recognition of a certain quality in a perceived action
+based on, or at least conjoined with, a particular emotional effect. In
+men's intuitive judgments respecting the right and the wrong, the noble
+and base, the admirable and contemptible, and so on, we may see the same
+kind of illusory universalizing of personal feeling as we have seen in
+their judgments respecting the beautiful. And the sources of the error
+are the same in the two cases. Accidents of experience, giving special
+associations to the actions, will not unfrequently warp the individual
+intuition. Ethical culture, like æsthetic culture, means a continual
+casting aside of early illusory habits of intuition. And further, moral
+intuition illustrates all those effects of feeling which we have briefly
+traced in the case of æsthetic intuition. The perversions of the moral
+intuition under the sway of prejudice are too familiar to need more than
+a bare allusion.
+
+
+_Nature of Insight._
+
+There remains one further mode of cognition which approximates in
+character to presentative knowledge, and is closely related to external
+perception. I refer to the commonly called "intuitive" process by which
+we apprehend the feelings and thoughts of other minds through the
+external signs of movement, vocal sound, etc., which make up expression
+and language. This kind of knowledge, which is not sufficiently marked
+off from external perception on the one side and introspection on the
+other, I venture to call Insight.
+
+I am well aware that this interpretation of the mental states of others
+is commonly described as a process of inference involving a conscious
+reference to our own similar experiences. I willingly grant that it is
+often so. At the same time, it must be perfectly plain that it is not
+always so. It is, indeed, doubtful whether in its first stages in early
+life it is invariably so, for there seem to be good reasons for
+attributing to the infant mind a certain degree of instinctive or
+inherited capability in making out the looks and tones of others.[107]
+And, however this may be, it is certain that with the progress of life a
+good part of this interpretation comes to be automatic or unconscious,
+approximating in character to a sense-perception. To recognize
+contentment in a placid smile is, one would say, hardly less immediate
+and intuitive than to recognize the coolness of a stream.
+
+We must, of course, all allow that the fusion of the presentative and
+the representative element is, speaking generally, more complete in the
+case of sense-perception than in that here considered. In spite of
+Berkeley's masterly account of the _rationale_ of visual perception as
+an interpretation of "visual language" and all that has confirmed it,
+the plain man cannot, at the moment of looking at an object, easily
+bring himself to admit that distance is not directly present to his
+vision. On the other hand, on cool reflection, he will recognize that
+the complacent benevolent sentiment is distinct from the particular
+movements and changes in the eye and other features which express it.
+Yet, while admitting this, I must contend that there is no very hard and
+fast line dividing the two processes, but that the reading of others'
+feelings approximates in character to an act of perception.
+
+An intuitive insight may, then, be defined as that instantaneous,
+automatic, or "unconscious" mode of interpreting another's feeling
+which occurs whenever the feeling is fully expressed, and when its signs
+are sufficiently familiar to us. This definition will include the
+interpretation of thoughts by means of language, though not, of course,
+the belief in an objective fact grounded on a recognition of another's
+belief. On the other hand, it will exclude all the more complex
+interpretations of looks and words which imply conscious comparison,
+reflection, and reasoning. Further, it will exclude a large part of the
+interpretation of actions as motived, since this, though sometimes
+approaching the intuitive form, is for the most part a process of
+conjectural or doubtful inference, and wanting in the immediate
+assurance which belongs to an intuitive reading of a present emotion or
+thought.
+
+From this short account of the process of insight, its relation to
+perception and introspection becomes pretty plain. On the one hand, it
+closely resembles sense-perception, since it proceeds by the
+interpretation of a sense-impression by means of a representative image.
+On the other hand, it differs from sense-perception, and is more closely
+allied to introspection in the fact that, while the process of
+interpretation in the former case is a reconstruction of _external_
+experiences, in the latter case it is a reconstruction of _internal_
+experiences. To intuit another's feeling is clearly to represent to
+ourselves a certain kind of internal experience previously known, in its
+elements at least, by introspection, while these represented experiences
+are distinctly referred to another personality.
+
+And now we see what constitutes the object of insight. This is, in part,
+a common experience, as in the case of sense-perception and æsthetic
+intuition, since to perceive another's feeling is implicitly to cognize
+the external conditions of a common insight. But this is clearly not the
+whole, nor even the main part of objective reality in this act of
+cognition. An intuitive insight differs from a sense-perception in that
+it involves an immediate assurance of the existence of a feeling
+presentatively known, though not to our own minds. The object in insight
+is thus a presentative feeling as in introspection, though not our own,
+but another's. And so it differs from the object in sense-perception in
+so far as this last involves sense-experiences, as muscular and tactual
+feelings, which are not _at the moment_ presentatively known to any
+mind.
+
+
+_Illusions of Insight._
+
+And now we are in a position, perhaps, to define an illusion of insight,
+and to inquire whether there is anything answering to our definition. An
+illusory insight is a quasi-intuition of another's feelings which does
+not answer to the internal reality as presentatively known to the
+subject himself. In spite of the errors of introspection dealt with in
+the last chapter, nobody will doubt that, when it is a question between
+a man's knowing what is at the moment in his own mind and somebody
+else's knowing, logic, as well as politeness, requires us to give
+precedence to the former.
+
+An illusion of insight, like the other varieties of illusion already
+dealt with, may arise either by way of wrong suggestion or by way of a
+warping preconception. Let us look at each of these sources apart.
+
+Our insights, like our perceptions, though intuitive in form, are
+obviously determined by previous experience, association, and habit.
+Hence, on its passive side, an illusion of insight may be described as a
+wrong interpretation of a new or exceptional case. For example, having
+associated the representation of a slight feeling of astonishment with
+uplifted eyebrows, we irresistibly tend to see a face in which this is a
+constant feature as expressing this particular shade of emotion. In this
+way we sometimes fall into grotesque errors as to mental traits. And the
+most practised physiognomist may not unfrequently err by importing the
+results of his special circle of experiences into new and unlike cases.
+
+Much the same thing occurs in language. Our timbre of voice, our
+articulation, and our vocabulary, like our physiognomy, have about them
+something individual, and error often arises from overlooking this, and
+hastily reading common interpretations into exceptional cases. The
+misunderstandings that arise even among the most open and confiding
+friends sufficiently illustrate this liability to error.
+
+Sometimes the error becomes more palpable, as, for example, when we
+visit another country. A foreign language, when heard, provokingly
+suggests all kinds of absurd meanings through analogies to our familiar
+tongue. Thus, the Englishman who visits Germany cannot, for a time, hear
+a lady use the expression, "Mein Mann," without having the amusing
+suggestion that the speaker is wishing to call special attention to the
+fact of her husband's masculinity. And doubtless the German who visits
+us derives a similar kind of amusement from such involuntary
+comparisons.
+
+A fertile source of illusory insight is, of course, conscious deception
+on the part of others. The rules of polite society require us to be
+hypocrites in a small way, and we have occasionally to affect the signs
+of amiability, interest, and amusement, when our actual sentiment is one
+of indifference, weariness, or even positive antipathy. And in this way
+a good deal of petty illusion arises. Although we may be well aware of
+the general untrustworthiness of this society behaviour, such is the
+force of association and habit, that the bland tone and flattering word
+irresistibly excite a momentary feeling of gratification, an effect
+which is made all the more easy by the co-operation of the recipient's
+own wishes, touched on in the last chapter.
+
+Among all varieties of this deception, that of the stage is the most
+complete. The actor is a man who has elaborately trained himself in the
+simulation of certain feelings. And when his acting is of the best
+quality, and the proper bodily attitude, gesture, tone of voice, and so
+on, are hit off, the force of the illusion completely masters us. For
+the moment we lose sight of the theatrical surroundings, and see the
+actor as really carried away by the passion which he so closely
+imitates. Histrionic illusion is as complete as any artistic variety can
+venture to be.[108]
+
+I have said that our insights are limited by our own mental experience,
+and so by introspection. In truth, every interpretation of another's
+look and word is determined ultimately, not by what we have previously
+observed in others, but by what we have personally felt, or at least
+have in a sense made our own by intense sympathy. Hence we may, in
+general, regard an illusion of insight on the active side as a hasty
+projection of our own feelings, thoughts, etc., into other minds.
+
+We habitually approach others with a predisposition to attribute to them
+our own modes of thinking and feeling. And this predisposition will be
+the more powerful, the more desirous we are for sympathy, and for that
+confirmation of our own views which the reflection of another mind
+affords. Thus, when making a new acquaintance, people are in general
+disposed to project too much of themselves into the person who is the
+object of inspection. They intuitively endow him with their own ideas,
+ways of looking at things, prejudices of sentiment, and so on, and
+receive something like a shock when later on they find out how different
+he is from this first hastily formed and largely performed image.
+
+The same thing occurs in the reading of literature, and the appreciation
+of the arts of expression generally. We usually approach an author with
+a predisposition to read our own habits of thought and sentiment into
+his words. It is probably a characteristic defect of a good deal of
+current criticism of remote writers to attribute to them too much of our
+modern conceptions and aims. Similarly, we often import our own special
+feelings into the utterances of the poet and of the musical composer.
+That much of this intuition is illusory, may be seen by a little
+attention to the "intuitions" of different critics. Two readers of
+unlike emotional organization will find incompatible modes of feeling in
+the same poet. And everybody knows how common it is for musical critics
+and amateurs to discover quite dissimilar feelings in the same
+composition.[109]
+
+The effect of this active projection of personal feeling will, of
+course, be seen most strikingly when there is a certain variety of
+feeling actually excited at the time in the observer's mind. A man who
+is in a particularly happy mood tends to reflect his exuberant gladness
+on others. The lover, in the moment of exalted emotion, reads a response
+to all his aspirations in his mistress's eyes. Again, a man will tend to
+project his own present ideas into the minds of others, and so imagine
+that they know what he knows; and this sometimes leads to a comical kind
+of embarrassment, and even to a betrayal of something which it was the
+interest of the person to keep to himself. Once more, in interpreting
+language, we may sometimes catch ourselves mistaking the meaning, owing
+to the presence of a certain idea in the mind at the time. Thus, if I
+have just been thinking of Comte, and overhear a person exclaim, "I'm
+positive," I irresistibly tend, for the moment, to ascribe to him an
+avowal of discipleship to the great positivist.
+
+
+_Poetic Illusion._
+
+The most remarkable example of this projection of feeling is
+undoubtedly illustrated in the poetic interpretation of inanimate
+nature. The personification of tree, mountain, ocean, and so on,
+illustrates, no doubt, the effect of association and external
+suggestion; for there are limits to such personification. But
+resemblance and suggestion commonly bear, in this case, but a small
+proportion to active constructive imagination. One might, perhaps, call
+this kind of projection the hallucination of insight, since there is
+nothing objective corresponding to the interpretative image.
+
+The imaginative and poetic mind is continually on the look out for hints
+of life, consciousness, and emotion in nature. It finds a certain kind
+of satisfaction in this half-illusory, dream-like transformation of
+nature. The deepest ground of this tendency must probably be looked for
+in the primitive ideas of the race, and the transmission by inheritance
+of the effect of its firmly fixed habits of mind. The undisciplined mind
+of early man, incapable of distinguishing the object of perception from
+the product of spontaneous imagination, and taking his own double
+existence as the type of all existence, actually saw the stream, the
+ocean, and the mountain as living beings; and so firmly rooted is this
+way of regarding objects, that even our scientifically trained minds
+find it a relief to relapse occasionally into it.[110]
+
+While there is this general imaginative disposition in the poetic mind
+to endow nature with life and consciousness, there are special
+tendencies to project the individual feelings into objects. Every
+imaginative mind looks for reflections of its own deepest feelings in
+the world about it. The lonely embittered heart, craving for sympathy,
+which he cannot meet with in his fellow-man, finds traces of it in the
+sighing of the trees or the moaning of the sad sea-wave. Our Poet
+Laureate, in his great elegy, has abundantly illustrated this impulse of
+the imagination to reflect its own emotional colouring on to inanimate
+things: for example in the lines--
+
+    "The wild unrest that lives in woe
+  Would dote and pore on yonder cloud
+  That rises upward always higher,
+     And onward drags a labouring breast,
+     And topples round the dreary west,
+  A looming bastion fringed with fire."
+
+So far I have been considering active illusions of insight as arising
+through the play of the impulse of the individual mind to project its
+feelings outwards, or to see their reflections in external things. I
+must now add that active illusion may be due to causes similar to those
+which we have seen to operate in the sphere of illusory perception and
+introspection. That is to say, there may be a disposition, permanent or
+temporary, to ascribe a certain kind of feeling to others in accordance
+with our wishes, fears, and so on.
+
+To give an illustration of the permanent causes, it is well known that a
+conceited man will be disposed to attribute admiration of himself to
+others. On the other hand, a shy, timid person will be prone to read
+into other minds the opposite kind of feeling.
+
+Coming to temporary forces, we find that any expectation to meet with a
+particular kind of mental trait in a new acquaintance will dispose the
+observer hastily and erroneously to attribute corresponding feelings to
+the person. And if this expectation springs out of a present feeling,
+the bias to illusory insight is still more powerful. For example, a
+child that fears its parent's displeasure will be prone to misinterpret
+the parent's words and actions, colouring them according to its fears.
+So an angry man, strongly desirous of making out that a person has
+injured him, will be disposed to see signs of conscious guilt in this
+person's looks or words. Similarly, a lover will read fine thoughts or
+sentiments into the mind of his mistress under the influence of a strong
+wish to admire.
+
+And what applies to the illusory interpretation of others' feelings
+applies to the ascription of feelings to inanimate objects. This is due
+not simply to the impulse to expand one's conscious existence through
+far-reaching resonances of sympathy, but also to a permanent or
+temporary disposition to attribute a certain kind of feeling to an
+object. Thus, the poet personifies nature in part because his emotional
+cravings prompt him to construct the idea of something that can be
+admired or worshipped. Once more, the action of a momentary feeling when
+actually excited is seen in the "mechanical" impulse of a man to
+retaliate when he strikes his foot against an object, as a chair, which
+clearly involves a tendency to attribute an intention to hurt to the
+unoffending body, and the _rationale_ of which odd procedure is pretty
+correctly expressed in the popular phrase: "It relieves the feelings."
+
+It is worth noting, perhaps, that these illusions of insight, like those
+of perception, may involve an inattention to the actual impression of
+the moment. To erroneously attribute a feeling to another through an
+excess of sympathetic eagerness is often to overlook what a perfectly
+dispassionate observer would see, as, for example, the immobility of the
+features or the signs of a deliberate effort to simulate. This
+inattention will, it is obvious, be greatest in the poetic attribution
+of life and personality to natural objects, in so far as this
+approximates to a complete momentary illusion. To see a dark overhanging
+rock as a grim sombre human presence, is for the moment to view it under
+this aspect only, abstracting from its many obvious unlikenesses.
+
+In the same manner, a tendency to read a particular meaning into a word
+may lead to the misapprehension of the word. To give an illustration: I
+was lately reading the fifth volume of G. H. Lewes's _Problems of Life
+and Mind_. In reading the first sentence of one of the sections, I again
+and again fell into the error of taking "The great Lagrange," for "The
+great Language." On glancing back I saw that the section was headed "On
+Language," and I at once recognized the cause of my error in the
+pre-existence in my mind of the representative image of the word
+"language."
+
+In concluding this short account of the errors of insight, I may observe
+that their range is obviously much greater than that of the previously
+considered classes of presentative illusion. This is, indeed, involved
+in what has been said about the nature of the process. Insight, as we
+have seen, though here classed with preservative cognition, occupies a
+kind of border-land between immediate knowledge or intuition and
+inference, shading off from the one to the other. And in the very nature
+of the case the scope for error must be great. Even overlooking human
+reticence, and, what is worse, human hypocrisy, the conditions of an
+accurate reading of others' minds are rarely realized. If, as has been
+remarked by a good authority, one rarely meets, even among intelligent
+people, with a fairly accurate observer of external things, what shall
+be said as to the commonly claimed power of "intuitive insight" into
+other people's thoughts and feelings, as though it were a process above
+suspicion? It is plain, indeed, on a little reflection, that, taking
+into account what is required in the way of large and varied experience
+(personal and social), a habit of careful introspection, as well as a
+habit of subtle discriminative attention to the external signs of mental
+life, and lastly, a freedom from prepossession and bias, only a very few
+can ever hope even to approximate to good readers of character.
+
+And then we have to bear in mind that this large amount of error is apt
+to remain uncorrected. There is not, as in the case of external
+perception, an easy way of verification, by calling in another sense; a
+misapprehension, once formed, is apt to remain, and I need hardly say
+that errors in these matters of mutual comprehension have their palpable
+practical consequences. All social cohesion and co-operation rest on
+this comprehension, and are limited by its degree of perfection. Nay,
+more, all common knowledge itself, in so far as it depends on a mutual
+communication of impressions, ideas, and beliefs, is limited by the
+fact of this great liability to error in what at first seems to be one
+of the most certain kinds of knowledge.
+
+In view of this depressing amount of error, our solace must be found in
+the reflection that this seemingly perfect instrument of intuitive
+insight is, in reality, like that of introspection, in process of being
+fashioned. Mutual comprehension has only become necessary since man
+entered the social state, and this, to judge by the evolutionist's
+measure of time, is not so long ago. A mental structure so complex and
+delicate requires for its development a proportionate degree of
+exercise, and it is not reasonable to look yet for perfect precision of
+action. Nevertheless, we may hope that, with the advance of social
+development, the faculty is continually gaining in precision and
+certainty. And, indeed, this hope is already assured to us in the fact
+that the faculty has begun to criticise itself, to distinguish between
+an erroneous and a true form of its-operation. In fact, all that has
+been here said about illusions of insight has involved the assumption
+that intellectual culture sharpens the power and makes it less liable to
+err.
+
+
+
+
+CHAPTER X.
+
+ILLUSIONS OF MEMORY.
+
+
+Thus far we have been dealing with Presentative Illusions, that is to
+say, with the errors incident to the process of what may roughly be
+called presentative cognition. We have now to pass to the consideration
+of Representative Illusion, or that kind of error which attends
+representative cognition in so far as it is immediate or
+self-sufficient, and not consciously based on other cognition. Of such
+immediate representative cognition, memory forms the most conspicuous
+and most easily recognized variety. Accordingly, I proceed to take up
+the subject of the Illusions of Memory.[111]
+
+The mystery of memory lies in the apparent immediateness of the mind's
+contact with the vanished past. In "looking back" on our life, we seem
+to ourselves for the moment to rise above the limitations of time, to
+undo its work of extinction, seizing again the realities which its
+on-rushing stream had borne far from us. Memory is a kind of
+resurrection of the buried past: as we fix our retrospective glance on
+it, it appears to start anew into life; forms arise within our minds
+which, we feel sure, must faithfully represent the things that were. We
+do not ask for any proof of the fidelity of this dramatic representation
+of our past history by memory. It is seen to be a faithful imitation,
+just because it is felt to be a revival of the past. To seek to make the
+immediate testimony of memory more sure seems absurd, since all our ways
+of describing and illustrating this mental operation assume that in the
+very act of performing it we do recover a part of our seemingly "dead
+selves."
+
+To challenge the veracity of a person's memory is one of the boldest
+things one can do in the way of attacking deep-seated conviction. Memory
+is the peculiar domain of the individual. In going back in recollection
+to the scenes of other years he is drawing on the secret store-house of
+his own consciousness, with which a stranger must not intermeddle. To
+cast doubt on a person's memory is commonly resented as an impertinence,
+hardly less rude than to question his reading of his own present mental
+state. Even if the challenger professedly bases his challenge on the
+testimony of his own memory, the challenged party is hardly likely to
+allow the right of comparing testimonies. He can in most cases boldly
+assert that those who differ from him are lacking in _his_ power of
+recollection. The past, in becoming the past, has, for most people,
+ceased to be a common object of reference; it has become a part of the
+individual's own inner self, and cannot be easily dislodged or shaken.
+
+Yet, although people in general are naturally disposed to be very
+confident about matters of recollection, reflective persons are pretty
+sure to find out, sooner or later, that they occasionally fall into
+errors of memory. It is not the philosopher who first hints at the
+mendacity of memory, but the "plain man" who takes careful note of what
+really happens in the world of his personal experience. Thus, we hear
+persons, quite innocent of speculative doubt, qualifying an assertion
+made on personal recollection by the proviso, "unless my memory has
+played me false." And even less reflective persons, including many who
+pride themselves on their excellent memory, will, when sorely pressed,
+make a grudging admission that they may, after all, be in error. Perhaps
+the weakest degree of such an admission, and one which allows to the
+conceding party a semblance of victory, is illustrated in the "last
+word" of one who has boldly maintained a proposition on the strength of
+individual recollection, but begins to recognize the instability of his
+position: "I either witnessed the occurrence or dreamt it." This is
+sufficient to prove that, with all people's boasting about the
+infallibility of memory, there are many who have a shrewd suspicion that
+some of its asseverations will not bear a very close scrutiny.
+
+
+_Psychology of Memory._
+
+In order to understand the errors of memory, we must proceed, as in the
+case of illusions of perception, by examining a little into the nature
+of the normal or correct process.
+
+An act of recollection is said by the psychologist to be purely
+representative in character, whereas perception is partly
+representative, partly preservative. To recall an object to the mind is
+to reconstruct the percept in the absence of a sense-impression.[112]
+
+An act of memory is obviously distinguished from one of simple
+imagination by the presence of a conscious reference to the past. Every
+recollection is an immediate reapprehension of some past object or
+event. However vague this reference may be, it must be there to
+constitute the process one of recollection.
+
+The every-day usages of language do not at first sight seem to
+consistently observe this distinction. When a boy says, "I remember my
+lesson," he appears to be thinking of the present only, and not
+referring to the past. In truth, however, there is a vague reference to
+the fact of retaining a piece of knowledge through a given interval of
+time.
+
+Again, when a man says, "I recollect your face," this means, "Your face
+seems familiar to me." Here again, though there is no definite reference
+to the past, there is a vague and indefinite one.
+
+It is plain from this definition that recollection is involved in all
+recognition or identification. Merely to be aware that I have seen a
+person before implies a minimum exercise of memory. Yet we may roughly
+distinguish the two actions of perception and recollection in the
+process of recognition. The mere recognition of an object does not
+imply the presence of a distinct representative or mnemonic image. In
+point of fact, in so far as recognition is assimilation, it cannot be
+said to imply a _distinct_ act of memory at all. It is only when
+similarity is perceived amid difference, only when the accompaniments or
+surroundings of the object as previously seen, differencing it from the
+object as now seen, are brought up to the mind that we may be said
+distinctly to recall the past. And our state of mind in recognizing an
+object or person is commonly an alternation between these two acts of
+separating the mnemonic image from the percept and so recalling or
+recollecting the past, and fusing the image and the percept in what is
+specifically marked off as recognition.[113]
+
+Although I have spoken of memory as a reinstatement in representative
+form of external experience, the term must be understood to include
+every revival of a past experience, whether external or internal, which
+is recognized as a revival. In a general way, the recallings of our
+internal feelings take place in close connection with the recollection
+of external circumstances or events, and so they may be regarded as
+largely conditioned by the laws of this second kind of reproduction.
+
+The old conceptions of mind, which regarded every mental phenomenon as a
+manifestation of an occult spiritual substance, naturally led to the
+supposition that an act of recollection involves the continued,
+unbroken existence of the reproductive or mnemonic image in the hidden
+regions of the mind. To recollect is, according to this view, to draw
+the image out of the dark vaults of unconscious mind into the upper
+chamber of illumined consciousness.
+
+Modern psychology recognizes no such pigeonhole apparatus in unconscious
+mind. On the purely psychical side, memory is nothing but an occasional
+reappearance of a past mental experience. And the sole mental conditions
+of this reappearance are to be found in the circumstances of the moment
+of the original experience and in those of the moment of the
+reappearance.
+
+Among these are to be specially noted, first of all, the degree of
+impressiveness of the original experience, that is to say, the amount of
+interest it awakened and of attention it excited. The more impressive
+any experience, the greater the chances of its subsequent revival.
+Moreover, the absence of impressiveness in the original experience may
+be made good either by a repetition of the actual experience or, in the
+case of non-recurring experiences, by the fact of previous mnemonic
+revivals.
+
+In the second place, the pre-existing mental states at the time of
+revival are essential conditions. It is now known that every
+recollection is determined by some link of association, that every
+mnemonic image presents itself in consciousness only when it has been
+preceded by some other mental state, presentative or representative,
+which is related to the image. This relation may be one of contiguity,
+that is to say, the original experiences may have occurred at the same
+time or in close succession; or one of similarity (partial and not
+amounting to identity), as where the sight of one place or person
+recalls that of another place or person. Finally, it is to be observed
+that recollection is often an act, in the full sense of that term,
+involving an effort of voluntary attention at the moment of revival.
+
+Modern physiology has done much towards helping us to understand the
+nervous conditions of memory. The biologist regards memory as a special
+phase of a universal property of organic structure, namely,
+modifiability by the exercise of function, or the survival after any
+particular kind of activity of a disposition to act again in that
+particular way. The revival of a mental impression in the weaker form of
+an image is thus, on its physical side, due in part to this remaining
+functional disposition in the central nervous tracts concerned. And so,
+while on the psychical or subjective side we are unable to find anything
+permanent in memory, on the physical or objective side we do find such a
+permanent substratum.
+
+With respect to the special conditions of mnemonic revival at any time,
+physiology is less explicit. In a general way, it informs us that such a
+reinstatement of the past is determined by the existence of certain
+connections between the nervous structures concerned in the reviving and
+revived mental elements. Thus, it is said that when the sound of a name
+calls up in the mind a visual image of a person seen some time since, it
+is because connections have been formed between particular regions and
+modes of activity of the auditory and the visual centres. And it is
+supposed that the existence of such connections is somehow due to the
+fact that the two regions acted simultaneously in the first instance,
+when the sight of the person was accompanied by the hearing of his name.
+In other words, the centres, as a whole, will tend to act at any future
+moment in the same complex way in which they have acted in past moments.
+
+All this is valuable hypothesis so far as it goes, though it plainly
+leaves much unaccounted for. As to why this reinstatement of a total
+cerebral pulsation in consequence of the re-excitation of a portion of
+the same should be accompanied by the specific mode of consciousness
+which we call recollection of something past, it is perhaps unreasonable
+to ask of physiology any sort of explanation.[114]
+
+Thus far as to the general or essential characteristics of memory on its
+mental and its bodily side. But what we commonly mean by memory is, on
+its psychical side at least, much more than this. We do not say that we
+properly recollect a thing unless we are able to refer it to some more
+or less clearly defined region of the past, and to localize it in the
+succession of experiences making up our mental image of the past. In
+other words, though we may speak of an imperfect kind of recollection
+where this definite reference is wanting, we mean by a perfect form of
+memory something which includes this reference.
+
+Without entering just now upon a full analysis of what this reference to
+a particular region of the past means, I may observe that it takes place
+by help of an habitual retracing of the past, or certain portions of it,
+that is to say, a regressive movement of the imagination along the lines
+of our actual experience. Setting out from the present moment, I can
+move regressively to the preceding state of consciousness, to the
+penultimate, and so on. The fact that each distinct mental state is
+continuous with the preceding and the succeeding, and in a certain sense
+overlaps these, makes any portion of our experience essentially a
+succession of states of consciousness, involving some rudimentary idea
+of time. And thus, whether I anticipate a future event or recall a past
+one, my imagination, setting out from the present moment, constructs a
+sequence of experiences of which the one particularly dwelt on is the
+other term or boundary. And our idea of the position of this last in
+time, like that of an object in space, is one of a relation to our
+present position, and is determined by the length of the sequence of
+experiences thus run over by the imagination.[115] It may be added that
+since the imagination can much more easily follow the actual order of
+experience than conceive it as reversed, the retrospective act of memory
+naturally tends to complete itself by a return movement forwards from
+the remembered event to the present moment.
+
+In practice this detailed retracing of successive moments of mental life
+is confined to very recent experiences. If I try to localize in time a
+remote event, I am content with placing it in relation to a series of
+prominent events or landmarks which serves me as a rough scheme of the
+past. The formation of such a mnemonic framework is largely due to the
+needs of social converse, which proceeds by help of a common standard of
+reference. This standard is supplied by those objective, that is to say,
+commonly experienced regularities of succession which constitute the
+natural and artificial divisions of the years, seasons, months, weeks,
+etc. The habit of recurring to these fixed divisional points of the past
+renders a return of imagination to any one of them more and more easy. A
+man has a definite idea of "a year ago" which the child wants, just
+because he has had so frequently to execute that vague regressive
+movement by which the idea arises. And though, as our actual point in
+time moves forward, the relative position of any given landmark is
+continually changing, the change easily adapts itself to that scheme of
+time-divisions which holds good for any present point.
+
+Few of our recollections of remote events involve a definite reference
+to this system of landmarks. The recollections of early life are, in the
+case of most people, so far as they depend on individual memory, very
+vaguely and imperfectly localized. And many recent experiences which are
+said to be half forgotten, are not referred to any clearly assignable
+position in time. One may say that in average cases definite
+localization characterizes only such supremely interesting personal
+experiences as spontaneously recur again and again to the mind. For the
+rest it is confined to those facts and events of general interest to
+which our social habits lead us repeatedly to go back.[116]
+
+The consciousness of personal identity is said to be bound up with
+memory. That is to say, I am conscious of a continuous permanent self
+under all the varying surface-play of the stream of consciousness, just
+because I can, by an act of recollection, bring together any two
+portions of this stream of experience, and so recognize the unbroken
+continuity of the whole. If this is so, it would seem to follow from the
+very fragmentary character of our recollections that our sense of
+identity is very incomplete. As we shall see presently, there is good
+reason to look upon, this consciousness of continuous personal existence
+as resting only in part on memory, and mainly on our independently
+formed representation of what has happened in the numberless and often
+huge lacunæ of the past left by memory.
+
+Having thus a rough idea of the mechanism of memory to guide us, we may
+be able to investigate the illusions incident to the process.
+
+
+_Illusions of Memory._
+
+By an illusion of memory we are to understand a false recollection or a
+wrong reference of an idea to some region of the past. It might,
+perhaps, be roughly described as a wrong interpretation of a special
+kind of mental image, namely, what I have called a mnemonic image.
+
+Mnemonic illusion is thus distinct from mere forgetfulness or imperfect
+memory. To forget or be doubtful about a past event is one thing; to
+seem to ourselves to remember it when we afterwards find that the fact
+was otherwise than we represented it in the apparent act of recollection
+is another thing. Indistinctness of recollection, or the decay of
+memory, is, as we shall soon see, an important co-operant condition of
+mnemonic illusion, but does not constitute it, any more than haziness of
+vision or disease of the visual organ, though highly favourable to
+optical illusion, can be said to constitute it.
+
+We may conveniently proceed in our detailed examination of illusions of
+memory, by distinguishing between three facts which appear to be
+involved in every complete and accurate process of recollection. When I
+distinctly recall an event, I am immediately sure of three things: (1)
+that something did really happen to me; (2) that it happened in the way
+I now think; and (3) that it happened when it appears to have happened.
+I cannot be said to recall a past event unless I feel sure on each of
+these points. Thus, to be able to say that an event happened at a
+particular date, and yet unable to describe how it happened, means that
+I have a very incomplete recollection. The same is true when I can
+recall an event pretty distinctly, but fail to assign it its proper
+date. This being so, it follows that there are three possible openings,
+and only three, by which errors of memory may creep in. And, as a matter
+of fact, each of these openings will be found to let in one class of
+mnemonic illusion. Thus we have (1) false recollections, to which there
+correspond no real events of personal history; (2) others which
+misrepresent the manner of happening of the events; and (3) others which
+falsify the date of the events remembered.
+
+It is obvious, from a mere glance at this threefold classification, that
+illusions of memory closely correspond to visual illusions. Thus, class
+(1) may be likened to the optical illusions known as subjective
+sensations of light, or ocular spectra. Here we can prove that there is
+nothing actually seen in the field of vision, and that the semblance of
+a visible object arises from quite another source than that of ordinary
+external light-stimulation, and by what may be called an accident.
+Similarly, in the case of the first class of mnemonic illusions, we
+shall find that there is nothing actually recollected, but that the
+mnemonic spectra or phantoms of recollected objects can be accounted for
+in quite another way. Such illusions come nearest to hallucinations in
+the region of memory.
+
+Again, class (2) has its visual analogue in those optical illusions
+which depend on effects of haziness and of the action of refracting
+media interposed between the eye and the object; in which cases, though
+there is some real thing corresponding to the perception, this is seen
+in a highly defective, distorted, and misleading form. In like manner,
+we can say that the images of memory often get obscured, distorted, and
+otherwise altered when they have receded into the dim distance, and are
+looked back upon through a long space of intervening mental experience.
+Finally, class (3) has its visual counterpart in erroneous perceptions
+of distance, as when, for example, owing to the clearness of the
+mountain atmosphere and the absence of intervening objects, the side of
+the Jungfrau looks to the inexperienced tourist at Wengernalp hardly
+further than a stone's throw. It will be found that when our memory
+falsifies the date of an event, the error arises much in the same way as
+a visual miscalculation of distance.
+
+This threefold division of illusions of memory is plainly a rather
+superficial one, and not based on distinctions of psychological nature
+or origin. In order to make our treatment of the subject scientific as
+well as popular, it will be necessary to introduce the distinction
+between the passive and the active factor under each head. It will be
+found, I think, without forcing the analogy too far, that here, as in
+the case of the illusions of perception and introspection, error is
+attributable now to misleading suggestion on the part of the mental
+content of the moment, now to a process of incorporating into this
+content a mental image not suggested by it, but existing independently.
+
+If we are to proceed as we did in the case of the illusions of sense,
+and take up the lower stages of error first of all, we shall need to
+begin with the third class of errors, those of localization in time, or
+of what may be called mnemonic perspective. It has been already observed
+that the definite localization of a mnemonic image is only an occasional
+accompaniment of what is loosely called recollection. Hence, error as
+to the position of an event in the past chain of events would seem to
+involve the least degree of violation of the confidence which we are
+wont to repose in memory. After this, we may proceed to the discussion
+of the second class, which I may call distortions of the mnemonic
+picture. And, finally, we may deal with the most signal and palpable
+variety of error of memory, namely, the illusions which I have called
+mnemonic spectra.
+
+
+_Illusions of Perspective: A. Definite Localization._
+
+In order to understand these errors of mnemonic perspective, we shall
+have to inquire more closely than we have yet done into the
+circumstances which customarily determine our idea of the degree of
+propinquity or of remoteness of a past event. And first of all, we will
+take the case of a complete act of recollection when the mind is able to
+travel back along an uninterrupted series of experiences to a definitely
+apprehended point. Here there would seem, at first sight, to be no room
+for error, since this movement of retrospective imagination may be said
+to involve a direct measurement of the distance, just as a sweep of the
+eye over the ground between a spectator and an object affords a direct
+measurement of the intervening space.
+
+Modern science, however, tells us that this mode of measurement is by no
+means the simple and accurate process which it at first seems to be. In
+point of fact, there is something like a constant error in all such
+retrospective measurement. Vierordt has proved experimentally, by making
+a person try to reproduce the varying time-intervals between the
+strokes of the pendulum of a metronome, that when the interval is a very
+small one, we uniformly tend to exaggerate it in retrospection; when a
+large one, to regard it, on the contrary, as less than it actually
+was.[117]
+
+A mere act of reflection will convince any one that when he tries to
+conceive a very small interval, say a quarter of a second, he is likely
+to make it too great. On the other hand, when we try to conceive a year,
+we do not fully grasp the whole extent of the duration. This is proved
+by the fact that merely by spending more time over the attempt, and so
+recalling a larger number of the details of the period, we very
+considerably enlarge our first estimate of the duration. And this leads
+to great discrepancies in the appreciation of the relative magnitudes of
+past sections of time. Thus, as Wundt observes, though in retrospect
+both a month and a year seem too short, the latter is relatively much
+more shortened than the former.[118]
+
+The cause of this constant error in the mode of reproducing durations
+seems to be connected with the very nature of the reproductive act. It
+must be borne in mind that this act is itself, like the experience which
+it represents, a mental process, occupying time, and that consequently
+it may very possibly reflect its time-character on the resulting
+judgment. Thus, since it certainly takes more than a quarter of a second
+to pass in imagination from one impression to another, it may be that we
+tend to confound this duration with that which we try to represent.
+Similarly, the fact that in the act of reproductive imagination we
+under-estimate a longer interval between two impressions, say those of
+the slow beats of a colliery engine, may be accounted for by the
+supposition that the imagination tends to pass from the one impression
+to the succeeding one too rapidly.[119]
+
+The gross misappreciation of duration of long periods of time, while it
+may illustrate the principle just touched on, clearly involves the
+effect of other and more powerful influences. A mere glance at what is
+in our mind when we recall such a period as a month or a year, shows
+that there is no clear concrete representation at all. Time, it has been
+often said, is known only so far as filled with concrete contents or
+conscious experiences, and a perfect imagination of any particular
+period of past time would involve a retracing of all the successive
+experiences which have gone to make up this section of our life. This, I
+need not say, never happens, both because, on the one hand, memory does
+not allow of a complete reproduction of any segment of our experience,
+and because, on the other hand, such an imaginative reproduction, even
+if possible, would clearly occupy as much time as the experience
+itself.[120]
+
+When I call up an image of the year just closing, what really happens is
+a rapid movement of imagination over a series of prominent events, among
+which the succession of seasons probably occupies the foremost place,
+serving, as I have remarked, as a framework for my retrospective
+picture. Each of the events which I thus run over is really a long
+succession of shorter experiences, which, however, I do not separately
+represent to myself. My imaginative reproduction of such a period is
+thus essentially a greatly abbreviated and symbolic mode of
+representation. It by no means corresponds to the visual imagination of
+a large magnitude, say that of the length of sea horizon visible at any
+one moment, which is complete in an instant, and quite independent of a
+successive imagination of its parts or details. It is essentially a very
+fragmentary and defective numerical idea, in which, moreover, the real
+quantitative value of the units is altogether lost sight of.
+
+Now, it seems to follow from this that there is something illusory in
+all our recallings of long periods of the past. It is by no means
+strictly correct to say that memory ever reinstates the past. It is more
+true to say that we see the past in retrospect as greatly foreshortened.
+Yet even this is hardly an accurate account of what takes place, since,
+when we look at an object foreshortened in perspective, we see enough to
+enable us imaginatively to reconstruct the actual size of the object,
+whereas in the case of time-perspective no such reconstruction is even
+indirectly possible.
+
+It is to be added that this constant error in time-reproduction is
+greater in the case of remote periods than of near ones of the same
+length. Thus, the retrospective estimate of a duration far removed from
+the present, say the length of time passed at a particular school, is
+much more superficial and fragmentary than that of a recent
+corresponding period. So that the time-vista of the past is seen to
+answer pretty closely to a visible perspective in which the amount of
+apparent error due to foreshortening increases with the distance.
+
+In practice, however, this defect in the imagination of duration leads
+to no error. Although, as a concrete image answering to some definite
+succession of experiences a year is a gross misrepresentation, as a
+general concept implying a collection of a certain number of similar
+successions of experience it is sufficiently exact. That is to say,
+though we cannot imagine the _absolute_ duration of any such cycle of
+experience, we can, by the simple device of conceiving certain durations
+as multiples of others, perfectly well compare different periods of
+times, and so appreciate their _relative_ magnitudes.
+
+Leaving, then, this constant error in time-appreciation, we will pass to
+the variable and more palpable errors in the retrospective measurement
+of time. Each person's experience will have told him that in estimating
+the distance of a past event by a mere retrospective sense of duration,
+he is liable to extraordinary fluctuations of judgment. Sometimes when
+the clock strikes we are surprised at the rapidity of the hour. At other
+times the timepiece seems rather to have lagged behind its usual pace.
+And what is true of a short interval is still more true of longer
+intervals, as months and years. The understanding of these fluctuations
+will be promoted by our brief glance at the constant errors in
+retrospective time-appreciation.
+
+And here it is necessary to distinguish between the sense of duration
+which we have during any period, and the retrospective sense which
+survives the period, for these do not necessarily agree. The former
+rests mainly on our prospective sense of time, whereas the latter must
+be altogether retrospective.[121]
+
+Our estimate of time as it passes is commonly said to depend on the
+amount of consciousness which we are giving to the fact of its
+transition. Thus, when the mind is unoccupied and suffering from
+_ennui_, we feel time to move sluggishly. On the other hand, interesting
+employment, by diverting the thoughts from time, makes it appear to move
+at a more rapid pace. This fact is shown in the common expressions which
+we employ, such as "to kill time," and the German _Langweile_.
+Similarly, it is said that when we are eagerly anticipating an event, as
+the arrival of a friend, the mere fact of dwelling on the interval makes
+it appear to swell out.[122]
+
+This view is correct in the main, and is seen, indeed, to follow from
+the great psychological principle that what we attend to exists for us
+more, has more reality, and so naturally seems greater than what we do
+not attend to. At the same time, this principle must be supplemented by
+another consideration. Suppose that I am very desirous that time should
+not pass quickly. If, for example, I am enjoying myself or indulging in
+idleness, and know that I have to be off to keep a not very agreeable
+engagement in a quarter of an hour, time will seem to pass too rapidly;
+and this not because my thoughts are diverted from the fact of its
+transition, for, on the contrary, they are reverting to it more than
+they usually do, but because my wish to lengthen the interval leads me
+to represent the unwelcome moment as further off than it actually is, in
+other words, to construct an ideal representation of the period in
+contrast with which the real duration looks miserably short.
+
+Our estimate of duration, when it is over, depends less on this
+circumstance of having attended to its transition than on other
+considerations. Wundt, indeed, seems to think that the feeling
+accompanying the actual flow of time has no effect on the surviving
+subjective appreciation; but this must surely be an error, since our
+mental image of any period is determined by the character of its
+contents. Wundt says that when once a tedious waiting is over, it looks
+short because we instantly forget the feeling of tedium. My
+self-observation, as well as the interrogation of others, has satisfied
+me, on the contrary, that this feeling distinctly colours the
+retrospective appreciation. Thus, when waiting at a railway station for
+a belated train, I am distinctly aware that each quarter of an hour
+looks long, not only as it passes, but when it is over. In fact, I am
+disposed to express my feeling as one of disappointment that only so
+short an interval has passed since I last looked at my watch.
+
+Nevertheless, I am ready to allow that, though a feeling of tedium, or
+the contrary feeling of irritation at the rapidity of time, will linger
+for an appreciable interval and colour the retrospective estimate of
+time, this backward view is chiefly determined by other considerations.
+As Wundt remarks, we have no sense of time's slowness during sleep, yet
+on waking we imagine that we have been dreaming for an immensely long
+period. This retrospective appreciation is determined by the number and
+the degree or intensity of the experiences, and, what comes very much to
+the same thing, by the amount of unlikeness, freshness, and
+discontinuity characterizing these experiences.
+
+Time, as I have already hinted, is known under the form of a succession
+of different conscious experiences. Unbroken uniformity would give us no
+sense of time, because it would give us no conscious experience at all.
+Strictly speaking, there is no such thing as a perfectly uniform mental
+state extending through an appreciable duration. In looking at one and
+the same object, even in listening to one and the same tone, I am in no
+two successive fractions of a second in exactly the same state of mind.
+Slight alterations in the strength of the sensation,[123] in the degree
+or direction of attention, and in the composition of that penumbra of
+vague images which it calls up, occur at every distinguishable fraction
+of time.
+
+This being so, it would seem to follow that the greater the number of
+clearly marked changes, and the more impressive and exciting these
+transitions, the fuller will be our sense of time. And this is borne out
+by individual reflection. When striking and deeply interesting events
+follow one another very rapidly, as when we are travelling, duration
+appears to swell out.
+
+It is possible that such a succession of stirring experiences may beget
+a vague consciousness of time at each successive moment, and apart from
+retrospection, simply by force of the change. In other words, without
+our distinctly attending to time, a series of novel impressions might,
+by giving us the consciousness of change, make us dimly aware of the
+numerical richness of our experiences. But, however this be, there is no
+doubt that, in glancing back on such a succession of exciting
+transitions of mental condition, time appears to expand enormously, just
+as it does in looking back on our dream-experience, or that rapid series
+of intensified feelings which, according to De Quincey and others, is
+produced by certain narcotics.
+
+The reason of this is plain. Such a type of successive experience offers
+to the retrospective imagination a large number of distinguishable
+points, and since this mode of estimating time depends, as we have seen,
+on the extent of the process of filling in, time will necessarily appear
+long in this case. On the other hand, when we have been engaged in very
+ordinary pursuits, in which few deeply interesting or exciting events
+have impressed themselves on memory, our retrospective picture will
+necessarily be very much of a blank, and consequently the duration of
+the period will seem to be short.
+
+I observed that this retrospective appreciation of time depended on the
+degree of connection between the successive experiences. This condition
+is very much the same as the other just given, namely, the degree of
+uniformity of the experiences, since the more closely the successive
+stages of the experience are connected--as when, for example, we are
+going through our daily routine of work--the more quiet and unexciting
+will be the transition from each stage to its succeeding one. And on the
+other hand, all novelty of impression and exciting transition of
+experience clearly involves a want of connection. Wundt thinks the
+retrospective estimate of a connected series of experiences, such as
+those of our daily round of occupations, is defective just because the
+effort of attention, which precedes even an imaginative reproduction of
+an impression, so quickly accommodates itself in this case to each of
+the successive steps, whereas, when the experiences to be recalled are
+disconnected, the effort requires more time. In this way, the estimate
+of a past duration would be coloured by the sense of time accompanying
+the reproductive process itself. This may very likely be the case, yet I
+should be disposed to attach most importance to the number of
+distinguishable items of experience recalled.
+
+Our representation of the position of a given event in the past is, as I
+have tried to show, determined by the movement of imagination in going
+back to it from the present. And this is the same thing as to say that
+it depends on our retrospective sense of the intervening space. That is
+to say, the sense of distance in time, as in space, is the recognition
+of a term to a movement. And just as the distance of an object will seem
+greater when there are many intervening objects affording points of
+measurement, than when there are none (as on the uniform surface of the
+sea), so the distance of an event will vary with the number of
+recognized intervening points.
+
+The appreciation of the distance of an event in time does not, however,
+wholly depend on the character of this movement of imagination. Just as
+the apparent distance of a visible object depends _inter alia_ on the
+distinctness of the retinal impression, so the apparent temporal
+remoteness of a past event depends in part on the degree of intensity
+and clearness of the mnemonic image. This is seen even in the case of
+those images which we are able distinctly to localize in the
+time-perspective. For a series of exciting experiences intervening
+between the present and a past event appears not only _directly_ to add
+to our sense of distance by constituting an apparently long interval,
+but _indirectly_ to add to it by giving an unusual degree of faintness
+to the recalled image. An event preceding some unusually stirring series
+of experiences gets thrust out of consciousness by the very engrossing
+nature of the new experiences, and so tends to grow more faint and
+ghost-like than it would otherwise have done.
+
+The full force of this circumstance is best seen in the fact that a very
+recent event, bringing with it a deep mental shock and a rapid stirring
+of wide tracts of feeling and thought, may get to look old in a
+marvellously short space of time. An announcement of the loss of a dear
+friend, when sudden and deeply agitating, will seem remote even after an
+hour of such intense emotional experience. And the same twofold
+consideration probably explains the well-known fact that a year seems
+much shorter to the adult than to the child. The novel and comparatively
+exciting impressions of childhood tend to fill out time in retrospect,
+and also to throw back remote events into a dimly discernible region.
+
+Now, this same circumstance, the degree of vividness or of faintness of
+the mnemonic image, is that which determines our idea of distance when
+the character of the intervening experiences produces no appreciable
+effect.[124] This is most strikingly illustrated in those imperfect
+kinds of recollection in which we are unable to definitely localize the
+mnemonic image. To the consideration of these we will now turn.
+
+
+B. _Indefinite Localization._
+
+Speaking roughly and generally, we may say that the vividness of an
+image of memory decreases in proportion as the distance of the event
+increases. And this is the rule which we unconsciously apply in
+determining distance in time. Nevertheless, this rule gives us by no
+means an infallible criterion of distance. The very fact that different
+people so often dispute about the dates and the order of past events
+experienced in common, shows pretty plainly that images of the same age
+tend to arise in the mind with very unequal degrees of vividness.
+
+Sometimes pictures of very remote incidents may suddenly present
+themselves to our minds with a singular degree of brightness and force.
+And when this is the case, there is a disposition to think of them as
+near. If the relations of the event to other events preceding and
+succeeding it are not remembered, this momentary illusion will persist.
+We have all heard persons exclaim, "It seems only yesterday," under the
+sense of nearness which accompanies a recollection of a remote event
+when vividly excited. The most familiar instance of such lively
+reproduction is the feeling which we experience on revisiting the scene
+of some memorable event. At such a time the past may return with
+something of the insistence of a present perceived reality. In passing
+from place to place, in talking with others, and in reading, we are
+liable to the sudden return by hidden paths of association of images of
+incidents that had long seemed forgotten, and when they thus start up
+fresh and vigorous, away from their proper surroundings, they invariably
+induce a feeling of the propinquity of the events.
+
+In many cases we cannot say why these particular images, long buried in
+oblivion, should thus suddenly regain so much vitality. There seems,
+indeed, to be almost as much that is arbitrary and capricious in the
+selection by memory of its vivid images as in the selection of its
+images as a whole; and, this being so, it is plain that we are greatly
+exposed to the risk of illusion from this source.
+
+There is an opposite effect in the case of recent occurrences that, for
+some reason or another, have left but a faint impression on the memory;
+though this fact is not, perhaps, so familiar as the other. I met a
+friend, we will suppose, a few days since at my club, and we exchanged a
+few words. My mind was somewhat preoccupied at the time, and the
+occurrence did not stamp itself on my recollection. To-day I meet him
+again, and he reminds me of a promise I made him at the time. His
+reminder suffices to restore a dim image of the incident, but the fact
+of its dimness leads to the illusion that it really happened much longer
+ago, and it is only on my friend's strong assurances, and on reasoning
+from other data that it must have occurred the day he mentions, that I
+am able to dismiss the illusion.
+
+The most striking examples of the illusory effect of mere vividness,
+involving a complete detachment of the event from the prominent
+landmarks of the past, are afforded by public events which lie outside
+the narrower circle of our personal life, and which do not in the
+natural course of things become linked to any definitely localized
+points in the field of memory. These events may be very stirring and
+engrossing for the time, but in many cases they pass out of the mind
+just as suddenly as they entered it. We have no occasion to revert to
+them, and if by chance we are afterwards reminded of them, they are
+pretty certain to look too near, just because the fact of their having
+greatly interested us has served to render their images particularly
+vivid.
+
+A curious instance of this illusory effect was supplied not long since
+by the case of the ex-detectives, the expiration of whose term of
+punishment (three years) served as an occasion for the newspapers to
+recall the event of their trial and conviction. The news that three
+years had elapsed since this well-remembered occurrence proved very
+startling to myself, and to a number of my friends, all of us agreeing
+that the event did not seem to be at more than a third of its real
+distance. More than one newspaper commented on the apparent rapidity of
+the time, and this shows pretty plainly that there was some cause at
+work, such as I have suggested, producing a common illusion.
+
+I have treated of these illusions connected with the estimate of past
+time and the dating of past events as passive illusions, not involving
+any active predisposition on the part of the imagination. At the same
+time, it is possible that error in these matters may occasionally depend
+on a present condition of the feelings and the imagination. It seems
+plain that since the apparent degree of remoteness of an event not
+distinctly localized in the past varies inversely as the degree of
+vividness of the mnemonic image, any conscious concentration of mind on
+a recollection will tend to bring it too near. In this way, then, an
+illusory propinquity may be given to a recalled event through a mere
+desire to dwell on it, or even a capricious wish to deceive one's self.
+
+When, for example, old friends come together and talk over the days of
+yore, there is a gradual reinstatement of seemingly lost experiences,
+which often partakes of the character of a semi-voluntary process of
+self-delusion. Through the cumulative effect of mutual reminder,
+incident after incident returns, adding something to the whole picture
+till it acquires a degree of completeness, coherence, and vividness that
+render it hardly distinguishable from a very recent experience. The
+process is like looking at a distant object through a field-glass.
+Mistiness disappears, fresh details come into view, till we seem to
+ourselves to be almost within reach of the object.
+
+Where the mind habitually goes back to some painful circumstance under
+the impulse of a morbid disposition to nurse regret, this momentary
+illusion may become recurring, and amount to a partial confusion of the
+near and the remote in our experience. An injury long brooded on seems
+at length a thing that continually moves forward as we move; it always
+presents itself to our memories as a very recent event. In states of
+insanity brought on by some great shock, we see this morbid tendency to
+resuscitate the dead past fully developed, and remote events and
+circumstances becoming confused with present ones.
+
+On the other hand, in more healthy states of mind there presents itself
+an exactly opposite tendency, namely, an impulse of the will to banish
+whatever when recalled gives pain to the furthest conceivable regions of
+the past. Thus, when we have lost something we cherished dearly, and the
+recollection of it brings fruitless longing, we instinctively seek to
+expel the recollection from our minds. The very feeling that what has
+been can never again be, seems to induce this idea of a vast remoteness
+of the vanished reality. When, moreover, the lost object was fitted to
+call forth the emotion of reverence, the impulse to magnify the
+remoteness of the loss may not improbably be reinforced by the
+circumstance that everything belonging to the distant past is fitted on
+that account to excite a feeling akin to reverence. So, again, any
+rupture in our mental development may lead us to exaggerate the distance
+of some past portion of our experience. When we have broken with our
+former selves, either in the way of worsening or bettering, we tend to
+project these further into the past.
+
+It is only when the sting of the recollection is removed, when, for
+example, the calling up of the image of a lost friend is no longer
+accompanied with the bitterness of futile longing, that a healthy mind
+ventures to nourish recollections of such remote events and to view
+these as part of its recent experiences. In this case the mnemonic image
+becomes transformed into a kind of present emotional possession, an
+element of that idealized and sublimated portion of our experience with
+which all imaginative persons fill up the emptiness of their actual
+lives, and to which the poet is wont to give an objective embodiment in
+his verse.
+
+
+_Distortions of Memory._
+
+It is now time to pass to the second group of illusions of memory,
+which, according to the analogy of visual errors, may be called
+atmospheric illusions. Here the degree of error is greater than in the
+case of illusions of time-perspective, since the very nature of the
+events or circumstances is misconceived. We do not recall the event as
+it happened, but see it in part only, and obscured, or bent and
+distorted as by a process of refraction. Indeed, this transformation of
+the past does closely correspond with the transformation of a visible
+object effected by intervening media. Our minds are such refracting
+media, and the past reappears to us not as it actually was when it was
+close to us, but in numerous ways altered and disguised by the
+intervening spaces of our conscious experience.
+
+To begin with, what we call recollection is uniformly a process of
+softening the reality. When we appear to ourselves to realize events of
+the remote past, it is plain that our representation in a general way
+falls below the reality: the vividness, the intensity of our impressions
+disappears. More particularly, so far as our experiences are emotional,
+they tend thus to become toned down by the mere lapse of time and the
+imperfections of our reproductive power. That which we seem to see in
+the act of recollection is thus very different from the reality.
+
+Not only is there this general deficiency in mnemonic representation,
+there are special deficiencies due to the fact of oblivescence. Our
+memories restore us only fragments of our past life. And just as objects
+seen imperfectly at a great distance may assume a shape quite unlike
+their real one, so an inadequate representation of a past event by
+memory often amounts to misrepresentation. When revisiting a place that
+we have not seen for many years, we are apt to find that our
+recollection of it consisted only of some insignificant details, which
+arranged themselves in our minds into something oddly unlike the actual
+scene. So, too, some accidental accompaniment of an incident in early
+life is preserved, as though it were the main feature, serving to give
+quite a false colouring to the whole occurrence.
+
+It seems quite impossible to account for these particular survivals,
+they appear to be so capricious. When a little time has elapsed after an
+event, and the attendant circumstances fade away from memory, it is
+often difficult to say why we were impressed with it as we afterwards
+prove to have been. It is no doubt possible to see that many of the
+recollections of our childhood owe their vividness to the fact of the
+exceptional character of the events; but this cannot always be
+recognized. Some of them seem to our mature minds very oddly selected,
+although no doubt there are in every case good reasons, if we could only
+discover them, why those particular incidents rather than any others
+should have been retained.
+
+The liability to error resulting from mere oblivescence and the
+arbitrary selection of mental images is seen most plainly, perhaps, in
+our subsequent representation and estimate of whole periods of early
+life. Our idea of any stage of our past history, as early childhood, or
+school days, is built up out of a few fragmentary intellectual relics
+which cannot be certainly known to answer to the most important and
+predominant experiences of the time. When, for example, we try to decide
+whether our school days were our happiest days, as is so often alleged,
+it is obvious that we are liable to fall into illusion through the
+inadequacy of memory to preserve characteristic or typical features, and
+none but these. We cannot easily recall the ordinary every-day level of
+feeling of a distant period of life, but rather think of exceptional
+moments of rejoicing or depression. The ordinary man's idea of the
+emotional experience of his school days is probably built up out of a
+few scrappy recollections of extraordinary and exciting events, such as
+unexpected holidays, success in the winning of prizes, famous "rows"
+with the masters, and so on.
+
+Besides the impossibility of getting at the average and prevailing
+mental tone of a distant section of life, there is a special difficulty
+in determining the degree of happiness of the past, arising from the
+fact that our memory for pleasures and for pains may not be equally
+good. Most people, perhaps, can recall the enjoyments of the past much
+more vividly than the sufferings. On the other hand, there seem to be
+some who find the retention of the latter the easier of the two. This
+fact should not be forgotten in reading the narrative of early hardships
+which some recent autobiographies have given us.
+
+Not only does our idea of the past become inexact by the mere decay and
+disappearance of essential features, it becomes positively incorrect
+through the gradual incorporation of elements that do not properly
+belong to it. Sometimes it is easy to see how these extraneous ideas get
+imported into our mental representation of a past event. Suppose, for
+example, that a man has lost a valuable scarf-pin. His wife suggests
+that a particular servant, whose reputation does not stand too high, has
+stolen it. When he afterwards recalls the loss, the chances are that he
+will confuse the fact with the conjecture attached to it, and say he
+remembers that this particular servant did steal the pin. Thus, the past
+activity of imagination serves to corrupt and partially falsify
+recollections that have a genuine basis of fact.
+
+It is evident that this class of mnemonic illusions approximates in
+character to illusions of perception. When the imagination supplies the
+interpretation at the very time, and the mind reads this into the
+perceived object, the error is one of perception. When the addition is
+made afterwards, on reflecting upon the perception, the error is one of
+memory. The "fallacies of testimony" which depend on an adulteration of
+pure observation with inference and conjecture, as, for example, the
+inaccurate and wild statements of people respecting their experiences at
+spiritualist _séances_, while they illustrate the curious blending of
+both kinds of error, are probably much oftener illusions of memory than
+of perception.[125]
+
+Although in many cases we can account to ourselves for this confusion of
+fact and imagination, in other cases it is difficult to see any close
+relation between the fact remembered and the foreign element imported
+into it. An idea of memory seems sometimes to lose its proper moorings,
+so to speak; to drift about helplessly among other ideas, and finally,
+by some chance, to hook itself on to one of these, as though it
+naturally belonged to it. Anybody who has had an opportunity of
+carefully testing the truthfulness of his recollection of some remote
+event in early life will have found how oddly extraneous elements become
+incorporated into the memorial picture. Incidents get put into wrong
+places, the wrong persons are introduced into a scene, and so on. Here
+again we may illustrate the mnemonic illusion by a visual one. When a
+tree standing before or behind a house and projecting above or to the
+side of it is not sharply distinguished from the latter, it may serve to
+give it a very odd appearance.
+
+These confusions of the mental image may arise even when only a short
+interval has elapsed. In the case of many of the fleeting impressions
+that are only half recollected, this kind of error is very easy. Thus,
+for example, I may have lent a book to a friend last week. I really
+remember the act of lending it, but have forgotten the person. But I am
+not aware of this. The picture of memory has unknowingly to myself been
+filled up by this unconscious process of shifting and rearrangement, and
+the idea of another person has by some odd accident got substituted for
+that of the real borrower. If we could go deeply enough into the matter,
+we should, of course, be able to explain why this particular confusion
+arose. We might find, for example, that the two persons were associated
+in my mind by a link of resemblance, or that I had dealings with the
+other person about the same time. Similarly, when we manage to join an
+event to a wrong place, we may find that it is because we heard of the
+occurrence when staying at the particular locality, or in some other way
+had the image of the place closely associated in our minds with the
+event. But often we are wholly unable to explain the displacement.
+
+So far I have been speaking of the passive processes by which the past
+comes to wear a new face to our imaginations. In these our present
+habits of feeling and thinking take no part; all is the work of the
+past, of the decay of memory, and the gradual confusion of images. This
+process of disorganization may be likened to the action of damp on some
+old manuscript, obliterating some parts, altering the appearance of
+others, and even dislocating certain portions. Besides this passive
+process of transformation, there is a more active one in which our
+present minds co-operate. In memory, as in perception and introspection,
+there is a process of preparation or preadjustment of mind, and here
+will be found room for what I had called active error. This may be
+illustrated by the operation of "interpreting" an old manuscript which
+has got partially obliterated, or of "restoring" a faded picture; in
+each of which operations error will be pretty sure to creep in through
+an importation of the restorer's own ideas into the relic of the past.
+
+Just as when distant objects are seen mistily our imaginations come into
+play, leading us to fancy that we see something completely and
+distinctly, so when the images of memory become dim, our present
+imagination helps to restore them, putting a new patch into the old
+garment. If only there is some relic of the past event preserved, a bare
+suggestion of the way in which it may have happened will often suffice
+to produce the conviction that it actually did happen in this way. The
+suggestions that naturally arise in our minds at such times will bear
+the stamp of our present modes of experience and habits of thought.
+Hence, in trying to reconstruct the remote past, we are constantly in
+danger of importing our present selves into our past selves.
+
+The kind of illusion of memory which thus depends on the spontaneous or
+independent activity of present imagination is strikingly illustrated in
+the curious cases of mistaken identity with which the proceedings of
+our law courts supply us from time to time. When a witness in good
+faith, but erroneously, affirms that a man is the same as an old
+acquaintance of his, we may feel sure that there is some striking point
+or points of similarity between the two persons. But this of itself
+would only partly account for the illusion, since we often see new faces
+that, by a number of curious points of affinity, call up in a
+tantalizing way old and familiar ones. What helps in this case to
+produce the illusion is the preconception that the present man is the
+witness's old friend. That is to say, his recollection is partly true,
+though largely false. He does really recall the similar feature,
+movement, or tone of voice; he only seems to himself to recall the rest
+of his friend's appearance; for, to speak correctly, he projects the
+present impression into the past, and constructs his friend's face out
+of elements supplied by the new one. Owing to this cause, an illusion of
+memory is apt to multiply itself, one man's assertion of what happened
+producing by contagion a counterfeit of memory's record in other minds.
+
+I said just now that we tend to project our present modes of experience
+into the past. We paint our past in the hues of the present. Thus we
+imagine that things which impressed us in some remote period of life
+must answer to what is impressive in our present stage of mental
+development. For example, a person recalls a hill near the home of his
+childhood, and has the conviction that it was of great height. On
+revisiting the place he finds that the eminence is quite insignificant.
+How can we account for this? For one thing, it is to be observed that to
+his undeveloped childish muscles the climbing to the top meant a
+considerable expenditure of energy, to be followed by a sense of
+fatigue. The man remembers these feelings, and "unconsciously reasoning"
+by present experience, that is to say, by the amount of walking which
+would now produce this sense of fatigue, imagines that the height was
+vastly greater than it really was. Another reason is, of course, that a
+wider knowledge of mountains has resulted in a great alteration of the
+man's standard of height.
+
+From this cause arises a tendency generally to exaggerate the
+impressions of early life. Youth is the period of novel effects, when
+all the world is fresh, and new and striking impressions crowd in
+thickly on the mind. Consequently, it takes much less to produce a given
+amount of mental excitation in childhood than in after-life. In looking
+back on this part of our history, we recall for the most part just those
+events and scenes which deeply stirred our minds by their strangeness,
+novelty, etc., and so impressed themselves on the tablet of our memory;
+and it is this sense of something out of the ordinary beat that gives
+the characteristic colour to our recollection. In other words, we
+remember something as wonderful, admirable, exceptionally delightful,
+and so on, rather than as a definitely imagined event. This being so, we
+unconsciously transform the past occurrence by reasoning from our
+present standard of what is impressive. Who has not felt an unpleasant
+disenchantment on revisiting some church, house, or park that seemed a
+wondrous paradise to his young eyes? All our feelings are capable of
+leading us into this kind of illusion. What seemed beautiful or awful
+to us as children, is now pictured in imagination as corresponding to
+what moves our mature minds to delight or awe. One cannot help wondering
+what we should think of our early heroes or heroines if we could see
+them again with our adult eyes exactly as they were.
+
+While the past may thus take on an illusory hue through the very
+progress of our experience and our emotional life, it may become further
+transformed by a more conscious process, namely, the idealizing touch of
+a present feeling. The way in which the emotions of love, reverence, and
+so on, thus transform their lost objects is too well known to need
+illustration. Speaking generally, we may say that in healthy minds the
+play of these impulses of feeling results in a softening of the harsher
+features of the past, and in an idealization of its happier and brighter
+aspects. As Wordsworth says, we may assign to Memory a pencil--
+
+  "That, softening objects, sometimes even
+     Outstrips the heart's demand;
+
+  "That smoothes foregone distress, the lines
+     Of lingering care subdues,
+   Long-vanished happiness refines,
+     And clothes in brighter hues."[126]
+
+Enough has now been said, perhaps, to show in how many ways our
+retrospective imagination transforms the actual events of our past life.
+So thoroughly, indeed, do the relics of this past get shaken together in
+new kaleidoscopic combinations, so much of the result of later
+experiences gets imported into our early years, that it may well be
+asked whether, if the record of our actual life were ever read out to
+us, we should be able to recognize it. It looks as though we could be
+sure of recalling only recent events with any degree of accuracy and
+completeness. As soon as they recede at any considerable distance from
+us, they are subject to a sort of atmospheric effect. Much grows
+indistinct and drops altogether out of sight, and what is still seen
+often takes a new and grotesquely unlike shape. More than this, the play
+of fancy, like the action of some refracting medium, bends and distorts
+the outlines of memory's objects, making them wholly unlike the
+originals.
+
+
+_Hallucinations of Memory._
+
+We will now go on to the third class of mnemonic error, which I have
+called the spectra of memory, where there is not simply a transformation
+of the past event, but a complete imaginative creation of it. This class
+of error corresponds, as I have observed, to an hallucination in the
+region of sense-perception. And just as we distinguished between those
+hallucinations of sense which arise first of all through some
+peripherally caused subjective sensation, and those which want even this
+element of reality and depend altogether on the activity of imagination,
+so we may mark off two classes of mnemonic hallucination. The false
+recollection may correspond to something past--and to this extent be a
+recollection--though not to any objective fact, but only to a subjective
+representation of such a fact, as, for example, a dream. In this case
+the imitation of the mnemonic process may be very definite and complete.
+Or the false recollection may be wholly a retrojection of a present
+mental image, and so by no stretch of language be deserving of the name
+recollection.
+
+It is doubtful whether by any effort of will a person could bring
+himself to regard a figment of his present imagination as representative
+of a past reality. Definite and complete hallucinations of this sort do
+not in normal circumstances arise. It seems necessary for a complete
+illusion of memory that there should be something past and recovered at
+the moment, though this may not be a real personal experience.[127] On
+the other hand, it is possible, as we shall presently see, under certain
+circumstances, to create out of present materials, and in a vague and
+indefinite shape, pure phantoms of past experience, that is to say,
+quasi-mnemonic images to which there correspond no past occurrences
+whatever.
+
+All recollection, as we have seen, takes place by means of a present
+mental image which returns with a certain degree of vividness, and is
+instantaneously identified with some past event. In many cases this
+instinctive process of identification proves to be legitimate, for, as a
+matter of fact, real impressions are the first and the commonest source
+of such lively mnemonic images. But it is not always so. There are other
+sources of our mental imagery which compete, so to speak, with the
+region of real personal experience. And sometimes these leave behind
+them a vivid image having all the appearance of a genuine mnemonic
+image. When this is so, it is impossible by a mere introspective glance
+to detect the falsity of the message from the past. We are in the same
+position as the purchaser in a jet market, where a spurious commodity
+has got inextricably mixed up with the genuine, and there is no ready
+criterion by which he can distinguish the true from the false. Such a
+person, if he purchases freely, is pretty sure to make a number of
+mistakes. Similarly, all of us are liable to take counterfeit mnemonic
+images for genuine ones; that is to say, to fall into an illusion of
+"recollecting" what never really took place.
+
+But what, it may be asked, are these false and illegitimate sources of
+mnemonic images, these unauthorized mints which issue a spurious mental
+coinage, and so confuse the genuine currency? They consist of two
+regions of our internal mental life, which most closely resemble the
+actual perception of real things in vividness and force, namely,
+dream-consciousness and waking imagination. Each of these may introduce
+into the mind vivid images which afterwards tend, under certain
+circumstances, to assume the guise of recollections of actual events.
+
+That our dream-experience may now and again lead us into illusory
+recollection has already been hinted. And it is easy to understand why
+this is so. When dreaming we have, as we have seen, a mental experience
+which closely approximates in intensity and reality to that of waking
+perception. Consequently, dreams may leave behind them, for a time,
+vivid images which simulate the appearance of real images of memory.
+Most of us, perhaps, have felt this after-effect of dreaming on our
+waking thoughts. It is sometimes very hard to shake off the impression
+left by a vivid dream, as, for example, that a dead friend has returned
+to life. During the day that follows the dream, we have at intermittent
+moments something like an assurance that we have seen our lost friend;
+and though we immediately correct the impression by reflecting that we
+are recalling but a dream, it tends to revive within us with a strange
+pertinacity.
+
+In addition to this proximate effect of a dream in disturbing the normal
+process of recollection, there is reason to suppose that dreams may
+exert a more remote effect on our memories. So widely different in its
+form is our dreaming from our waking experience, that our dreams are
+rarely recalled as wholes with perfect distinctness. They revive in us
+only as disjointed fragments, and only for brief moments when some
+accidental resemblance in the present happens to stir the latent trace
+they have left on our minds. We get sudden flashes out of our
+dream-world, and the process is too rapid, too incomplete for us to
+identify the region whence the flashes come.
+
+It is highly probable that our dreams are, to a large extent, answerable
+for the sense of familiarity that we sometimes experience in visiting a
+new locality or in seeing a new face. If, as we have found some of the
+best authorities saying, we are, when asleep, always dreaming more or
+less distinctly, and if, as we know, dreaming is a continual process of
+transformation of our waking impressions in new combinations, it is not
+surprising that our dreams should sometimes take the form of forecasts
+of our waking life, and that consequently objects and scenes of this
+life never before seen should now and again wear a familiar look.
+
+That some instances of this puzzling sense of familiarity can be
+explained in this way is proved. Thus, Paul Radestock, in the work
+_Schlaf und Traum_, already quoted, tells us: "When I have been taking a
+walk, with my thoughts quite unfettered, the idea has often occurred to
+me that I had seen, heard, or thought of this or that thing once before,
+without being able to recall when, where, and in what circumstances.
+This happened at the time when, with a view to the publication of the
+present work, I was in the habit of keeping an exact record of my
+dreams. Consequently, I was able to turn to this after these
+impressions, and on doing so I generally found the conjecture confirmed
+that I had previously dreamt something like it." Scientific inquiry is
+often said to destroy all beautiful thoughts about nature and life; but
+while it destroys it creates. Is it not almost a romantic idea that just
+as our waking life images itself in our dreams, so our dream-life may
+send back some of its shadowy phantoms into our prosaic every-day world,
+touching this with something of its own weird beauty?
+
+Not only may dreams beget these momentary illusions of memory, they may
+give rise to something like permanent illusions. If a dream serves to
+connect a certain idea with a place or person, and subsequent experience
+does not tend to correct this, we may keep the belief that we have
+actually witnessed the event. And we may naturally expect that this
+result will occur most frequently in the case of those who habitually
+dream vividly, as young children.
+
+It seems to me that many of the quaint fancies which children get into
+their heads about things they hear of arise in this way. I know a person
+who, when a child, got the notion that when his baby-brother was weaned,
+he was taken up on a grassy hill and tossed about. He had a vivid idea
+of having seen this curious ceremony. He has in vain tried to get an
+explanation of this picturesque rendering of an incident of babyhood
+from his friends, and has come to the conclusion that it was the result
+of a dream. If, as seems probable, children's dreams thus give rise to
+subsequent illusions of memory, the fact would throw a curious light on
+some of the startling quasi-records of childish experience to be met
+with in autobiographical literature.
+
+Odd though it may at first appear, old age is said to resemble youth in
+this confusion of dream-recollection with the memory of waking
+experience. Dr. Carpenter[128] tells us of "a lady of advanced age
+who ... continually dreams about passing events, and seems entirely unable
+to distinguish between her dreaming and her waking experiences,
+narrating the former with implicit belief in them, and giving directions
+based on them." This confusion in the case of the old may possibly
+arise not from an increase in the intensity of the dreams, but from a
+decrease in the intensity of the waking impressions. As Sir Henry
+Holland remarks,[129] in old age life approaches to the state of a
+dream.
+
+The other source of what may, by analogy with the hallucinations of
+sense, be called the peripherally originating spectra of memory is
+waking imagination. In certain morbid conditions of mind, and in the
+case of the few healthy minds endowed with special imaginative force,
+the products of this mental activity, may, as we saw when dealing with
+illusions of perception, closely resemble dreams in their vividness and
+apparent actuality. When this is the case, illusions of memory may arise
+at once just as in the case of dreams. This will happen more easily when
+the imagination has for some time been occupied with the same group of
+ideal scenes, persons, or events. To Dickens, as is well known, his
+fictitious characters were for the time realities, and after he had
+finished his story their forms and their doings lingered with him,
+assuming the aspect of personal recollections. So, too, the energetic
+activity of imagination which accompanies a deep and absorbing sympathy
+with another's painful experiences, may easily result in so vivid a
+realization of all their details as to leave an after-sense of
+_personal_ suffering. All highly sympathetic persons who have closely
+accompanied beloved friends through a great sorrow have known something
+of this subsequent feeling.
+
+The close connection and continuity between normal and abnormal states
+of mind is illustrated in the fact that in insanity the illusion of
+taking past imaginations for past realities becomes far more powerful
+and persistent. Abercrombie (_Intellectual Powers_, Part III. sec. iv. §
+2, "Insanity") speaks of "visions of the imagination which have formerly
+been indulged in of that kind which we call waking dreams or
+castle-building recurring to the mind in this condition, and now
+believed to have a real existence." Thus, for example, one patient
+believed in the reality of the good luck previously predicted by a
+fortune-teller. Other writers on mental disease observe that it is a
+common thing for the monomaniac to cherish the delusion that he has
+actually gained the object of some previous ambition, or is undergoing
+some previously dreaded calamity.
+
+Nor is it necessary to these illusions of memory that there should be
+any exceptional force of imagination. A fairly vivid representation to
+ourselves of anything, whether real or fictitious, communicated by
+others, will often result in something very like a personal
+recollection. In the case of works of history and fiction, which adopt
+the narrative tense, this tendency to a subsequent illusion of memory is
+strengthened by the disposition of the mind at the moment of reading to
+project itself backwards as in an act of recollection. This is a point
+which will be further dealt with in the next chapter.
+
+In most cases, however, illusions of memory growing out of previous
+activities of the imagination appear only after the lapse of some time,
+when in the natural course of things the mental images derived from
+actual experience would sink to a certain degree of faintness. Habitual
+novel-readers often catch themselves mistaking the echo of some passage
+in a good story for the trace left by an actual event. A person's name,
+a striking saying, and even an event itself, when we first come across
+it or experience it, may for a moment seem familiar to us, and to recall
+some past like impression, if it only happens to resemble something in
+the works of a favourite novelist. And so, too, any recital of another's
+experience, whether oral or literary, if it deeply interests us and
+awakens a specially vivid imagination of the events described, may
+easily become the starting-point of an illusory recollection.
+
+Children are in the habit of "drinking in" with their vigorous and eager
+imaginations what is told them and read to them, and hence they are
+specially likely to fall into this kind of error. Not only so: when they
+grow up and their early recollections lose their definiteness, becoming
+a few fragments saved from a lost past, it must pretty certainly happen
+that if any ideas derived from these recitals are preserved, they will
+simulate the form of memories. Thus, I have often caught myself for a
+moment under the sway of the illusion that I actually visited the
+Exhibition of 1851, the reason being that I am able to recall the
+descriptions given to me of it by my friends, and the excitement
+attending their journey to London on the occasion. It is to be added
+that repetition of the act of imagination will tend still further to
+deepen the subsequent feeling that we are recollecting something. As
+Hartley well observes, a man, by repeating a story, easily comes to
+suppose that he remembers it.[130]
+
+Here, then, we have another source of error that we must take into
+account in judging of the authenticity of an autobiographical narration
+of the events of childhood. The more imaginative the writer, the greater
+the risk of illusion from this source as well as from that of
+dream-fancies. It is highly probable, indeed, that in such full and
+explicit records of very early life as those given by Rousseau, by
+Goethe, or by De Quincey, some part of the quasi-narrative is based on
+mental images which come floating down the stream of time, not from the
+substantial world of the writer's personal experience, but from the airy
+region of dream-land or of waking fancy.
+
+It is to be added that even when the quasi-recollection does answer to a
+real event of childish history, it may still be an illusion. The fact
+that others, in narrating events to us, are able to awaken imaginations
+that afterwards appear as past realities, suggests that much of our
+supposed early recollection owes its existence to what our parents and
+friends have from time to time told us respecting the first stages of
+our history.[131] We see, then, how much uncertainty attaches to all
+autobiographical description of very early life.
+
+Modern science suggests another possible source of these distinct
+spectra of memory. May it not happen that, by the law of hereditary
+transmission, which is now being applied to mental as well as bodily
+phenomena, ancestral experiences will now and then reflect themselves
+in our mental life, and so give rise to apparently personal
+recollections? No one can say that this is not so. When the infant first
+steadies his eyes on a human face, it may, for aught we know, experience
+a feeling akin to that described above, when through a survival of
+dream-fancy we take some new scene to be already familiar. At the age
+when new emotions rapidly develop themselves, when our hearts are full
+of wild romantic aspirations, do there not seem to blend with the eager
+passion of the time deep resonances of a vast and mysterious past, and
+may not this feeling be a sort of reminiscence of prenatal, that is,
+ancestral experience?
+
+This idea is certainly a fascinating one, worthy to be a new scientific
+support for the beautiful thought of Plato and of Wordsworth. But in our
+present state of knowledge, any reasoning on this supposition would
+probably appear too fanciful. Some day we may find out how much
+ancestral experience is capable of bequeathing in this way, whether
+simply shadowy, undefinable mental tendencies, or something like
+definite concrete ideas. If, for example, it were found that a child
+that was descended from a line of seafaring ancestors, and that had
+never itself seen or heard of the "dark-gleaming sea," manifested a
+feeling of recognition when first beholding it, we might be pretty sure
+that such a thing as recollection of prenatal events does take place.
+But till we have such facts, it seems better to refer the "shadowy
+recollections" to sources which fall within the individual's own
+experience.
+
+We may now pass to those hallucinations of memory which are analogous to
+the _centrally_ excited hallucinations of sense-perception. As I have
+observed, these are necessarily vague and imperfectly developed.
+
+I have already had occasion to touch on the fact of the vast amount of
+our forgotten experience. And I observed that forgetfulness was a common
+negative condition of mnemonic illusion. I have now to complete this
+statement by the observation that total forgetfulness of any period or
+stage of our past experience necessarily tends to a vague kind of
+hallucination. In looking back on the past, we see no absolute gaps in
+the continuity of our conscious life; our image of this past is
+essentially one of an unbroken series of conscious experiences. But if
+through forgetfulness a part of the series is effaced from memory, how,
+it may be asked, is it possible to construct this perfectly continuous
+line? The answer is that we fill up such lacunæ vaguely by help of some
+very imperfectly imagined common type of conscious experience. Just as
+the eye sees no gap in its field of vision corresponding to the "blind
+spot" of the retina, but carries its impression over this area, so
+memory sees no lacuna in the past, but carries its image of conscious
+life over each of the forgotten spaces.
+
+Sometimes this process of filling in gaps in the past becomes more
+complete. Thus, for example, in recalling a particular night a week or
+so ago, I instinctively represent it to myself as so many hours of lying
+in bed with the waking sensations appropriate to the circumstances, as
+those of bodily warmth and rest, and of the surrounding silence and
+darkness.
+
+It is apparent that I cannot conceive myself apart from some mode of
+conscious experience. In thinking of myself in any part of the past or
+future in which there is actually no consciousness, or of which the
+conscious content is quite unknown to me, I necessarily imagine myself
+as consciously experiencing something. If I picture myself under any
+definitely conceived circumstances, I irresistibly import into my mental
+image the feelings appropriate to these surroundings. In this way,
+people tend to imagine themselves after death as lying in the grave,
+feeling its darkness and its chilliness. If the circumstances of the
+time are not distinctly represented, the conception of the conscious
+experience which constitutes that piece of the ego is necessarily vague,
+and seems generally to resolve itself into a representation of ourselves
+as dimly _self-conscious_. What this consciousness of self consists of
+is a point that will be taken up presently.
+
+
+_Illusions with respect to Personal Identity._
+
+It would seem to follow from these errors in imaginatively filling up
+our past life, that our consciousness of personal identity is by no
+means the simple and exact process which it is commonly supposed to be.
+I have already remarked that the very fact of there being so large a
+region of the irrevocable in our past experience proves our
+consciousness of personal continuity to be largely a matter of
+inference, or of imaginative conjecture, and not simply of immediate
+recollection. Indeed, it may be said that our power of ignoring whole
+regions of the past and of leaping complacently over huge gaps in our
+memory and linking on conscious experience with conscious experience,
+involves an illusory sense of continuity, and so far of personal
+identity. Thus, our ordinary image of our past life, if only by omitting
+the very large fraction passed in sleep, in at least an approximately
+unconscious state, clearly contains an ingredient of illusion.[132]
+
+It is to be added that the numerous falsifications of our past history,
+which our retrospective imagination is capable of perpetrating, make our
+representation of ourselves at different moments and in different stages
+of our past history to a considerable extent illusory. Thus, though to
+mistake a past dream-experience for a waking one may not be to lose or
+confuse the sense of identity, since our dreams are, after all, a part
+of our experience, yet to imagine that we have ourselves seen what we
+have only heard from another or read is clearly to confuse the
+boundaries of our identity. And with respect to longer sections of our
+history, it is plain that when we wrongly assimilate our remote to our
+present self, and clothe our childish nature with the feelings and the
+ideas of our adult life, we identify ourselves overmuch. In this way,
+through the corruption of our memory, a kind of sham self gets mixed up
+with the real self, so that we cannot, strictly speaking, be sure that
+when we project a mnemonic image into the remote past we are not really
+running away from our true personality.
+
+So far I have been touching only on slight errors in the recognition of
+that identical self which is represented as persisting through all the
+fluctuations of conscious life. Other and grosser illusions connected
+with personal identity are also found to be closely related to defects
+or disturbances of the ordinary mnemonic process, and so can be best
+treated here. In order to understand these, we must inquire a little
+into the nature of our idea and consciousness of a persistent self.
+Here, again, I would remind the reader that I am treating the point only
+so far as it can be treated scientifically or empirically, that is to
+say, by examining what concrete facts or data of experience are taken up
+into the idea of self. I do not wish to foreclose the philosophic
+question whether anything more than this empirical content is involved
+in the conception.
+
+My idea of myself as persisting appears to be built up of certain
+similarities in the succession of my experiences. Thus, my permanent
+self consists, on the bodily side, of a continually renewable perception
+of my own organism, which perception is mainly visual and tactual, and
+which remains pretty constant within certain limits of time. With this
+objective similarity is closely conjoined a subjective similarity. Thus,
+the same sensibilities continue to characterize the various parts of my
+organism. Similarly, there are the higher intellectual, emotional, and
+moral peculiarities and dispositions. My idea of my persistent self is
+essentially a collective image representing a relatively unchanging
+material object, endowed with unchanging sensibilities and forming a
+kind of support for permanent higher mental attributes.
+
+The construction of this idea of an enduring unchanging ego is rendered
+very much easier by the fact that certain concrete feelings are
+approximately constant elements in our mental life. Among these must be
+ranked first that dimly discriminated mass of organic sensation which in
+average states of health is fairly constant, and which stands in sharp
+contrast to the fluctuating external sensations. These feelings enter
+into and profoundly colour each person's mental image of himself. In
+addition to this, there are the frequently recurring higher feelings,
+the dominant passions and ideas which approximate more or less closely
+to constant factors of our conscious experience.
+
+This total image of the ego becomes defined and rendered precise by a
+number of distinctions, as that between my own body or that particular
+material object with which are intimately united all my feelings, and
+other material objects in general; then between my organism and other
+human organisms, with which I learn to connect certain feelings
+answering to my own, but only faintly represented instead of actually
+realized feelings. To these prime distinctions are added others, hardly
+less fundamental, as those between my individual bodily appearance and
+that of other living bodies, between my personal and characteristic
+modes of feeling and thinking and those of others, and so on.
+
+Our sense of personal identity may be said to be rooted in that special
+side of the mnemonic process which consists in the linking of all
+sequent events together by means of a thread of common consciousness. It
+is closely connected with that smooth, gliding movement of imagination
+which appears to involve some more or less distinct consciousness of the
+uniting thread of similarity. And so long as this movement is possible,
+so long, that is to say, as retrospective imagination detects the common
+element, which we may specifically call the recurring consciousness of
+self, so long is there the undisturbed assurance of personal identity.
+Nay, more, even when such a recognition might seem to be difficult, if
+not impossible, as in linking together the very unlike selves, viewed
+both on their objective and subjective sides, of childhood, youth, and
+mature life, the mind manages, as we have seen, to feign to itself a
+sufficient amount of such similarity.
+
+But this process of linking stage to stage, of discerning the common or
+the recurring amid the changing and the evanescent, has its limits.
+Every great and sudden change in our experience tends, momentarily at
+least, to hinder the smooth reflux of imagination. It makes too sharp a
+break in our conscious life, so that imagination is incapable of
+spanning the gap and realizing the then and the now as parts of a
+connected continuous tissue.[133]
+
+These changes may be either objective or subjective. Any sudden
+alteration of our bodily appearance sensibly impedes the movement of
+imagination. A patient after a fever, when he first looks in the glass,
+exclaims, "I don't know myself." More commonly the bodily changes which
+affect the consciousness of an enduring self are such as involve
+considerable alterations of coenæsthesis, or the mass of stable
+organic sensation. Thus, the loss of a limb, by cutting off a portion of
+the old sensations through which the organism may be said to be
+immediately felt, and by introducing new and unfamiliar feelings, will
+distinctly give a shock to our consciousness of self.
+
+Purely subjective changes, too, or, to speak correctly, such as are
+known subjectively only, will suffice to disturb the sense of personal
+unity. Any great moral shock, involving something like a revolution in
+our recurring emotional experience, seems at the moment to rupture the
+bond of identity. And even some time after, as I have already remarked,
+such cataclysms in our mental geology lead to the imaginative thrusting
+of the old personality away from the new one under the form of a "dead
+self."[134]
+
+We see, then, that the failure of our ordinary assurance of personal
+identity is due to the recognition of difference without similarity. It
+arises from an act of memory--for the mind must still be able to recall
+the past, dimly at least--but from a memory which misses its habitual
+support in a recognized element of constancy. If there is no memory,
+that is to say, if the past is a complete blank, the mind simply feels a
+rupture of identity without any transformation of self. This is our
+condition on awaking from a perfectly forgotten period of sleep, or from
+a perfectly unconscious state (if such is possible) when induced by
+anæsthetics. Such gaps are, as we have seen, easily filled up, and the
+sense of identity restored by a kind of retrospective "skipping." On the
+other hand, the confusion which arises from too great and violent a
+transformation of our _remembered_ experiences is much less easily
+corrected. As long as the recollection of the old feelings remains, and
+with this the sense of violent contrast between the old and the new
+ones, so long will the illusion of two sundered selves tend to recur.
+
+The full development of this process of imaginative fission or cleavage
+of self is to be met with in mental disease. The beginnings of such
+disease, accompanied as they commonly are with disturbances of bodily
+sensations and the recurring emotions, illustrate in a very interesting
+way the dependence of the recognition of self on a certain degree of
+uniformity in the contents of consciousness. The patient, when first
+aware of these changes, is perplexed, and often regards the new feelings
+as making up another self, a foreign _Tu_, as distinguished from the
+familiar _Ego_. And sometimes he expresses the relation between the old
+and the new self in fantastic ways, as when he imagines the former to be
+under the power of some foreign personality.
+
+When the change is complete, the patient is apt to think of his former
+self as detached from his present, and of his previous life as a kind of
+unreal dream; and this fading away of the past into shadowy unreal forms
+has, as its result, a curious aberration in the sense of time. Thus, it
+is said that a patient, after being in an asylum only one day, will
+declare that he has been there a year, five years, and even ten
+years.[135] This confusion as to self naturally becomes the
+starting-point of illusions of perception; the transformation of self
+seeming to require as its logical correlative (for there is a crude
+logic even in mental disease) a transformation of the environment. When
+the disease is fully developed under the particular form of monomania,
+the recollection of the former normal self commonly disappears
+altogether, or fades away into a dim image of some perfectly separate
+personality. A new ego is now fully substituted for the old. In other
+and more violent forms of disease (dementia) the power of connecting the
+past and present may disappear altogether, and nothing but the _disjecta
+membra_ of an ego remain.
+
+       *       *       *       *       *
+
+Enough has, perhaps, been said to show how much of uncertainty and of
+self-deception enters into the processes of memory. This much-esteemed
+faculty, valuable and indispensable though it certainly is, can clearly
+lay no claim to that absolute infallibility which is sometimes said to
+belong to it. Our individual recollection, left to itself, is liable to
+a number of illusions even with regard to fairly recent events, and in
+the case of remote ones it may be said to err habitually and uniformly
+in a greater or less degree. To speak plainly, we can never be certain
+on the ground of our personal recollection alone that a distant event
+happened exactly in the way and at the time that we suppose. Nor does
+there seem to be any simple way by mere reflection on the contents of
+our memory of distinguishing what kinds of recollection are likely to be
+illusory.
+
+How, then, it may be asked, can we ever be certain that we are
+faithfully recalling the actual events of the past? Given a fairly good,
+that is, a cultivated memory, it may be said that in the case of very
+recent events a man may feel certain that, when the conditions of
+careful attention at the time to what really happened were present, a
+distinct recollection is substantially correct. Also it is obvious that
+with respect to all repeated experiences our memories afford practically
+safe guides. When memory becomes the basis of some item of generalized
+knowledge, as, for example, of the truth that the pain of indigestion
+has followed a too copious indulgence in rich food, there is little room
+for an error of memory properly so called. On the other hand, when an
+event is not repeated in our experience, but forms a unique link in our
+personal history, the chances of error increase with the distance of the
+event; and here the best of us will do well to have resort to a process
+of verification or, if necessary, of correction.
+
+In order thus to verify the utterances of memory, we must look beyond
+our own internal mental states to some external facts. Thus, the
+recollections of our early life may often be tested by letters written
+by ourselves or our friends at the time, by diaries, and so on. When
+there is no unerring objective record to be found, we may have recourse
+to the less satisfactory method of comparing our recollections with
+those of others. By so doing we may reach a rough average recollection
+which shall at least be free from any individual error corresponding to
+that of personal equation in perception. But even thus we cannot be sure
+of eliminating all error, since there may be a cause of illusion acting
+on all our minds alike, as, for example, the extraordinary nature of the
+occurrence, which would pretty certainly lead to a common exaggeration
+of its magnitude, etc., and since, moreover, this process of comparing
+recollections affords an opportunity for that reading back a present
+preconception into the past to which reference has already been made.
+
+The result of our inquiry is less alarming than it looks at first sight.
+Knowledge is valuable for action, and error is chiefly hurtful in so far
+as it misdirects conduct. Now, in a general way, we do not need to act
+upon a recollection of single remote events; our conduct is sufficiently
+shaped by an accurate recollection of single recent events, together
+with those bundles of recollections of recurring events and sequences of
+events which constitute our knowledge of ourselves and our common
+knowledge of the world about us. Nature has done commendably well in
+endowing us with the means of cultivating our memories up to this point,
+and we ought not to blame her for not giving us powers which would only
+very rarely prove of any appreciable practical service to us.
+
+
+
+
+NOTE.
+
+MOMENTARY ILLUSIONS OF SELF-CONSCIOUSNESS.
+
+
+The account of the apparent ruptures in our personal identity given in
+this chapter may help us to understand the strange tendency to confuse
+self with other objects which occasionally appears in waking
+consciousness and in dreams. These errors may be said generally to be
+due to the breaking up of the composite image of self into its
+fragments, and the regarding of certain of these only. Thus, the
+momentary occurrence of partial illusion in intense sympathy with
+others, including that imaginative projection of self into inanimate
+objects, to which reference has already been made, may be said to depend
+on exclusive attention to the subjective aspect of self, to the total
+disregard of the objective aspect. In other words, when we thus
+momentarily "lose ourselves," or merge our own existence in that of
+another object, we clearly let drop out of sight the visual
+representation of our own individual organism. On the other hand, when
+in dreams we double our personality, or represent to ourselves an
+external self which becomes the object of visual perception, it is
+probably because we isolate in imagination the objective aspect of our
+personality from the other and subjective aspect. It is not at all
+unlikely that the several confusions of self touched on in this chapter
+have had something to do with the genesis of the various historical
+theories of a transformed existence, as, for example, the celebrated
+doctrine of metempsychosis.
+
+
+
+
+CHAPTER XI.
+
+ILLUSIONS OF BELIEF.
+
+
+Our knowledge is commonly said to consist of two large
+varieties--Presentative and Representative. Representative knowledge,
+again, falls into two chief divisions. The first of these is Memory,
+which, though not primary or original, like presentative knowledge, is
+still regarded as directly or intuitively certain. The second division
+consists of all other representative knowledge besides memory,
+including, among other varieties, our anticipations of the future, our
+knowledge of others' past experience, and our general knowledge about
+things. There is no one term which exactly hits off this large sphere of
+cognition: I propose to call it Belief. I am aware that this is by no
+means a perfect word for my purpose, since, on the one hand, it suggests
+that every form of this knowledge must be less certain than presentative
+or mnemonic knowledge, which cannot be assumed; and since, on the other
+hand, the word is so useful a one in psychology, for the purpose of
+marking off the subjective fact of assurance in all kinds of cognition.
+Nevertheless, I know not what better one I could select in order to
+make my classification answer as closely as a scientific treatment will
+allow to the deeply fixed distinctions of popular psychology.
+
+It might at first seem as if perception, introspection, and memory must
+exhaust all that is meant by immediate, or self-evident, knowledge, and
+as if what I have here called belief must be uniformly mediate,
+derivate, or inferred knowledge. The apprehension of something now
+present to the mind, externally or internally, and the reapprehension
+through the process of memory of what was once so apprehended, might
+appear to be the whole of what can by any stretch of language be called
+direct cognition of things. This at least would seem to follow from the
+empirical theory of knowledge, which regards perception and memory as
+the ground or logical source of all other forms of knowledge.
+
+And even if we suppose, with some philosophers, that there are certain
+innate principles of knowledge, it seems now to be generally allowed
+that these, apart from the particular facts of experience, are merely
+abstractions; and that they only develop into complete knowledge when
+they receive some empirical content, which must be supplied either by
+present perception or by memory. So that in this case, too, all definite
+concrete knowledge would seem to be either presentative cognition,
+memory, or, lastly, some mode of inference from these.
+
+A little inquiry into the mental operations which I here include under
+the name belief will show, however, that they are by no means uniformly
+process of inference. To take the simplest form of such knowledge,
+anticipation of some personal experience: this may arise quite apart
+from recollection, as a spontaneous projection of a mental image into
+the future. A person may feel "intuitively certain" that something is
+going to happen to him which does not resemble anything in his past
+experience. Not only so; even when the expectation corresponds to a bit
+of past experience, this source of the expectation may, under certain
+circumstances, be altogether lost to view, and the belief assume a
+secondarily automatic or intuitive character. Thus, a man may have first
+entertained a belief in the success of some undertaking as the result of
+a rough process of inference, but afterwards go on trusting when the
+grounds for his confidence are wholly lost sight of.
+
+This much may suffice for the present to show that belief sometimes
+approximates to immediate, or self-evident, conviction. How far this is
+the case will come out in the course of our inquiry into its different
+forms. This being so, it will be needful to include in our present study
+the errors connected with the process of belief in so far as they
+simulate the immediate instantaneous form of illusion.
+
+What I have here called belief may be roughly distinguished into simple
+and compound belief. By a simple belief I mean one which has to do with
+a single event or fact. It includes simple modes of expectation, as well
+as beliefs in single past facts not guaranteed by memory. A compound
+belief, on the other hand, has reference to a number of events or facts.
+Thus, our belief in the continued existence of a particular object, as
+well as our convictions respecting groups or classes of events, must be
+regarded as compound, since they can be shown to include a number of
+simple beliefs.
+
+
+A. _Simple Illusory Belief: Expectation._
+
+It will be well to begin our inquiry by examining the errors connected
+with simple expectations, so far as these come under our definition of
+illusion. And here, following our usual practice, we may set out with a
+very brief account of the nature of the intellectual process in its
+correct form. For this purpose we shall do well to take a complete or
+definite anticipation of an event as our type.[136]
+
+The ability of the mind to move forward, forecasting an order of events
+in time, is clearly very similar to its power of recalling events. Each
+depends on the capability of imagination to represent a sequence of
+events or experiences. The difference between the two processes is that
+in anticipation the imagination setting out from the present traces the
+succession of experiences in their actual order, and not in the reverse
+order. It would thus appear to be a more natural and easy process than
+recollection, and observation bears out this conclusion. Any object
+present to perception which is associated with antecedents and
+consequents with the same degree of cohesion, calls up its consequents
+rather than its antecedents. The spectacle of the rising of the sun
+carries the mind much more forcibly forwards to the advancing morning
+than backwards to the receding night. And there is good reason to
+suppose that in the order of mental development the power of distinctly
+expecting an event precedes that of distinctly recollecting one. Thus,
+in the case of the infant mind, as of the animal intelligence, the
+presence of signs of coming events, as the preparation of food, seems to
+excite distinct and vivid expectation.[137]
+
+As a mode of assurance, expectation is clearly marked off from memory,
+and is not explainable by means of this. It is a fundamentally distinct
+kind of conviction. So far as we are capable of analyzing it, we may say
+that its peculiarity is its essentially active character. To expect a
+thing is to have stirred the active impulses, including the powers of
+attention; it is to be on the alert for it, to have the attention
+already focussed for it, and to begin to rehearse the actions which the
+actual happening of the event--for example, the approach of a welcome
+object--would excite. It thus stands in marked contrast to memory, which
+is a passive attitude of mind, becoming active only when it gives rise
+to the expectation of a recurrence of the event.[138]
+
+And now let us pass to the question whether expectation ever takes the
+form of immediate knowledge. It may, perhaps, be objected that the
+anticipation of something future cannot be knowledge at all in the sense
+in which the perception of something present or the recollection of
+something past is knowledge. But this objection, when examined closely,
+appears to be frivolous. Because the future fact has not yet come into
+the sphere of actual existence, it is none the less the object of a
+perfect assurance.[139]
+
+But, even if it is conceded that expectation is knowledge, the objection
+may still be urged that it cannot be immediate, since it is the very
+nature of expectation to ground itself on memory. I have already hinted
+that this is not the case, and I shall now try to show that what is
+called expectation covers much that is indistinguishable from immediate
+intuitive certainty, and consequently offers room for an illusory form
+of error.
+
+Let us set out with the simplest kind of expectation, the anticipation
+of something about to happen within the region of our personal
+experience, and similar to what has happened before. And let the coming
+of the event be first of all suggested by some present external fact or
+sign. Suppose, for example, that the sky is heavy, the air sultry, and
+that I have a bad headache; I confidently anticipate a thunderstorm. It
+would commonly be said that such an expectation is a kind of inference
+from the past. I remember that these appearances have been followed by a
+thunderstorm very often, and I infer that they will in this new case be
+so followed.
+
+To this, however, it may be replied that in most cases there is no
+conscious going back to the past at all. As I have already remarked,
+anticipation is pretty certainly in advance of memory in early life. And
+even after the habit of passing from the past to the future, from memory
+to expectation, has been formed, the number of the past repetitions of
+experience would prevent the mind's clearly reverting to them. And,
+further, the very force of habit would tend to make the transition from
+memory to expectation more and more rapid, automatic, and unconscious.
+Thus it comes about that all distinctly suggested approaching events
+seem to be expected by a kind of immediate act of belief. The present
+signs call up the representation of the coming event with all the force
+of a direct intuition. At least, it may be said that if a process of
+inference, it is one which has the minimum degree of consciousness.
+
+It might still be urged that the mind passes from the _present_ facts as
+signs, and so still performs a kind of reasoning process. This is, no
+doubt, true, and differentiates expectation from perception, in which
+there is no conscious transition from the presented to the represented.
+Still I take it that this is only a process of reasoning in so far as
+the sign is consciously generalized, and this is certainly not true of
+early expectations, or even of any expectations in a wholly uncultivated
+mind.
+
+For these reasons I think that any errors involved in such an
+anticipation may, without much forcing, be brought under our definition
+of illusion. When due altogether to the immediate force of suggestion in
+a present object or event, and not involving any conscious transition
+from past to future, or from general truth to particular instance, these
+errors appear to me to have more of the character of illusions than of
+that of fallacies.
+
+Much the same thing may be said about the vivid anticipations of a
+familiar kind of experience called up by a clear and consecutive verbal
+suggestion. When a man, even with an apparent air of playfulness, tells
+me that something is going to happen, and gives a consistent consecutive
+account of this, I have an anticipation which is not consciously
+grounded on any past experience of the value of human testimony in
+general, or of this person's testimony in particular, but which is
+instantaneous and quasi-immediate. Consequently, any error connected
+with the mental act approximates to an illusion.
+
+So far I have supposed that the anticipated event is a recurring one,
+that is to say, a kind of experience which has already become familiar
+to us. This, however, holds good only of a very few of our experiences.
+Our life changes as it progresses, both outwardly and inwardly. Many of
+our anticipations, when first formed, involve much more than a
+reproduction of a past experience, namely, a complex act of constructive
+imagination. Our representations of these untried experiences, as, for
+example, those connected with a new set of circumstances, a new social
+condition, a new mode of occupation, and so on, are clearly at the first
+far from simple processes of inference from the past. They are put
+together by the aid of many fragmentary images, restored by distinct
+threads of association, yet by a process so rapid as to appear like an
+intuition. Indeed, the anticipation of such new experiences more often
+resembles an instantaneous imaginative intuition than a process of
+conscious transition from old experiences. In the case of these
+expectations, then, there would clearly seem to be room for illusion
+from the first.
+
+But even supposing that the errors connected with the first formation of
+an expectation cannot strictly be called illusory, we may see that such
+simple expectation will, in certain cases, tend to grow into something
+quite indistinguishable from illusion. I refer to expectations of
+_remote_ events which allow of frequent renewal. Even supposing the
+expectation to have originated from some rational source, as from a
+conscious inference from past experience, or from the acceptance of
+somebody's statement, the very habit of cherishing the anticipation
+tends to invest it with an automatic self-sufficient character. To all
+intents and purposes the prevision becomes intuitive, by which I mean
+that the mind is at the time immediately certain that something is going
+to happen, without needing to fall back on memory or reflection. This
+being so, whenever the initial process of inference or quasi-inference
+happens to have been bad, an illusory expectation may arise. In other
+words, the force of repetition and habit tends to harden what may, in
+its initial form, have resembled a kind of fallacy into an illusion.
+
+And now let us proceed further. When a permanent expectation is thus
+formed, there arises the possibility of processes which favour illusion
+precisely analogous to those which we have studied in the case of
+memory.
+
+In the first place, the habit of imagining a future event is attended
+with a considerable amount of illusion as to time or remoteness. After
+what has been said respecting the conditions of such error in the case
+of memory, a very few words will suffice here.
+
+It is clear, then, in the first place, that the mind will tend to
+shorten any period of future time, and so to antedate, so to speak, a
+given event, in so far as the imagination is able clearly and easily to
+run over its probable experiences. From this it follows that repeated
+forecastings of series of events, by facilitating the imaginative
+process, tend to beget an illusory appearance of contraction in the time
+anticipated. Moreover, since in anticipation so much of each division of
+the future time-line is unknown, it is obviously easy for the expectant
+imagination to skip over long intervals, and so to bring together widely
+remote events.
+
+In addition to this general error, there are more special errors. As in
+the case of recollection, vividness of mental image suggests
+propinquity; and accordingly, all vivid anticipations, to whatever cause
+the vividness may be owing, whether to powerful suggestion on the part
+of external objects, to verbal suggestion, or to spontaneous imagination
+and feeling, are apt to represent their objects as too near.
+
+It follows that an event intensely longed for, in so far as the
+imagination is busy in representing it, will seem to approach the
+present. At the same time, as we have seen, an event much longed for
+commonly appears to be a great while coming, the explanation being that
+there is a continually renewed contradiction between anticipation and
+perception. The self-adjustment of the mind in the attitude of
+expectant attention proves again and again to be vain and futile, and it
+is this fact which brings home to it the slowness of the sequences of
+perceived fact, as compared with the rapidity of the sequences of
+imagination.
+
+When speaking of the retrospective estimate of time, I observed that the
+apparent distance of an event depends on our representation of the
+intervening time-segment. And the same remark applies to the prospective
+estimate. Thus, an occurrence which we expect to happen next week will
+seem specially near if we know little or nothing of the contents of the
+intervening space, for in this case the imagination does not project the
+experience behind a number of other distinctly represented events.
+
+Finally, it is to be remarked that the prospective appreciation of any
+duration will tend to err relatively by way of excess, where the time is
+exceptionally filled out with clearly expected and deeply interesting
+experiences. To the imagination of the child, a holiday, filled with new
+experiences, appears to be boundless.
+
+Thus far I have assumed that the date of the future event is a matter
+which might be known. It is, however, obvious, from the very nature of
+knowledge with respect to the future, that we may sometimes be certain
+of a thing happening to us without knowing with any degree of
+definiteness when it will happen. In the case of these temporally
+undefined expectations, the law already expounded holds good that all
+vividness of representation tends to lend the things represented an
+appearance of approaching events. On the other hand, there are some
+events, such as our own death, which our instinctive feelings tend to
+banish to a region so remote as hardly to be realized at all.
+
+So much with respect to errors in the localizing of future events.
+
+In the second place, a habit of imagining a future event or group of
+events will give play to those forces which tend to transform a mental
+image. In other words, the habitual indulgence of a certain anticipation
+tends to an illusory view, not only of the "when?" but also of the
+"how?" of the future event. These transformations, due to subtle
+processes of emotion and intellect, and reflecting the present habits of
+these, exactly resemble those by which a remembered event becomes
+gradually transformed. Thus, we carry on our present habits of thought
+and feeling into the remote future, foolishly imagining that at a
+distant period of life, or in greatly altered circumstances, we shall
+desire and aim at the same things as now in our existing circumstances.
+In close connection with this forward projection of our present selves,
+there betrays itself a tendency to look on future events as answering to
+our present desires and aspirations. In this way, we are wont to soften,
+beautify, and idealize the future, marking it off from the hard
+matter-of-fact present.
+
+The less like the future experience to our past experience, or the more
+remote the time anticipated, the greater the scope for such imaginative
+transformation. And from this stage of fanciful transformation of a
+future reality to the complete imaginative creation of such a reality,
+the step is but a small one. Here we reach the full development of
+illusory expectation, that which corresponds to hallucination in the
+region of sense-perception.
+
+In order to understand these extreme forms of illusory expectation, it
+will be necessary to say something more about the relation of
+imagination to anticipation in general. There are, I conceive, good
+reasons for saying that any kind of vivid imagination tends to pass into
+a semblance of an expectation of a coming personal experience, or an
+event that is about to happen within the sphere of our own observation.
+It has long been recognized by writers, among whom I may mention Dugald
+Stewart, that to distinctly imagine an event or object is to feel for
+the moment a degree of belief in the corresponding reality. Now, I have
+already said that expectation is probably a more natural and an earlier
+developed state of mind than memory. And so it seems probable that any
+mental image which happens to take hold on the mind, if not recognized
+as one of memory, or as corresponding to a fact in somebody else's
+experience, naturally assumes the form of an expectation of a personal
+experience. The force of the expectation will vary in general as the
+vividness and persistence of the mental image. Moreover, it follows,
+from what has been said, that this force of imagination will determine
+what little time-character we ever give to these wholly ungrounded
+illusions.
+
+We see, then, that any process of spontaneous imagination will tend to
+beget some degree of illusory expectation. And among the agencies by
+which such ungrounded imagination arises, the promptings of feeling play
+the most conspicuous part. A present emotional excitement may give to an
+imaginative anticipation, such as that of the prophetic enthusiast, a
+reality which approximates to that of an actually perceived object. And
+even where this force of excitement is wanting, a gentle impulse of
+feeling may suffice to beget an assurance of a distant reality. The
+unknown recesses of the remote future offer, indeed, the field in which
+the illusory impulses of our emotional nature have their richest
+harvest.
+
+  "Thus, from afar, each dim discover'd scene
+   More pleasing seems than all the past hath been;
+   And every form, that Fancy can repair
+   From dark oblivion, glows divinely there."
+
+The recurring emotions, the ruling aspirations, find objects for
+themselves in this veiled region. Feelings too shy to burst forth in
+unseemly anticipation of the immediate future, modestly satisfy
+themselves with this remote prospect of satisfaction. And thus, there
+arises the half-touching, half-amusing spectacle of men and women
+continually renewing illusory hopes, and continually pushing the date of
+their realization further on as time progresses and brings no actual
+fruition.
+
+So far I have spoken of such expectations as refer to future personal
+experience only. Growing individual experience and the enlargement of
+this by the addition of social experience enable us to frame a number of
+other beliefs more or less similar to the simple expectations just dealt
+with. Thus, for example, I can forecast with confidence events which
+will occur in the lives of others, and which I shall not even witness;
+or again, I may even succeed in dimly descrying events, such as
+political changes or scientific discoveries, which will happen after my
+personal experience is at an end. Once more, I can believe in something
+going on now at some distant and even inaccessible point of the
+universe, and this appears to involve a conditional expectation, and to
+mean that I am certain that I or anybody else would see the phenomenon,
+if we could at this moment be transported to the spot.
+
+All such previsions are supposed to be formed by a process of inference
+from personal experience, including the trustworthiness of testimony.
+Even allowing, however, that this was so in the first stages of the
+belief, it is plain that, by dint of frequent renewal, the expectation
+would soon cease to be a process of inference, and acquire an apparently
+self-evident character. This being so, if the expectation is not
+adequately grounded to start with, it is very likely to develop into an
+illusion. And it is to be added that these permanent anticipations may
+have their origin much more in our own wishes or emotional promptings
+than in fact and experience. The mind undisciplined by scientific
+training is wont to entertain numerous beliefs of this sort respecting
+what is now going on in unvisited parts of the world, or what will
+happen hereafter in the distant future. The remote, and therefore
+obscure, in space and in time has always been the favourite region for
+the projection of pleasant fancies.
+
+Once more, besides these oblique kinds of expectation, I may form other
+seemingly simple beliefs, to which the term expectation seems less
+clearly applicable. Thus, on waking in the morning and finding the
+ground covered with snow, my imagination moves backwards, as in the
+process of memory, and realizes the spectacle of the softly falling
+snow-flakes in the hours of the night. The oral communication of others'
+experience, including the traditions of the race, enables me to set out
+from any present point of time, and reconstruct complex chains of
+experience of vast length lying beyond the bounds of my own personal
+recollection.
+
+I need not here discuss what the exact nature of such beliefs is. J.S.
+Mill identifies them with expectations. Thus, according to him, my
+belief in the nocturnal snowstorm is the assurance that I should have
+seen it had I waited up during the night. So my belief in Cicero's
+oratory resolves itself into the conviction that I should have heard
+Cicero under certain conditions of time and place, which is identical
+with my expectation that I shall hear a certain speaker to-morrow if I
+go to the House of Commons.[140] However this be, the thing to note is
+that such retrospective beliefs, when once formed, tend to approximate
+in character to recollections. This is true even of new beliefs in
+recent events directly made known by present objective consequences or
+signs, as the snowstorm. For in this case there is commonly no conscious
+comparison of the present signs with previously known signs, but merely
+a direct quasi-mnemonic passage of mind from the present fact to its
+antecedent. And it is still more true of long-entertained retrospective
+beliefs. When, for example, the original grounds of an historical
+hypothesis are lost sight of, and after the belief has hardened and
+solidified by time, it comes to look much more like a recollection than
+an expectation. As a matter of fact, we have seen, when studying the
+illusions of memory, that our personal experience does become confused
+with that of others. And one may say that all long-cherished
+retrospective beliefs tend to become assimilated to recollections.
+
+Here then, again, there seems to be room for illusion to arise. Even in
+the case of a recent past event, directly made known by present
+objective signs, the mind is liable to err just as in the case of
+forecasting an immediately approaching event. And such error has all the
+force of an illusion: its contradiction is almost as great a shock as
+that of a recollection. When, for example, I enter my house, and see a
+friend's card lying on the table, I so vividly represent to myself the
+recent call of my friend, that when I learn the card is an old one which
+has accidentally been put on the table, I experience a sense of
+disillusion very similar to that which attends a contradicted
+perception. The early crude stages of physical science abundantly
+illustrate the genesis of such illusions.
+
+It may be added that if there be any feeling present in the mind at the
+time, the barest suggestion of something having happened will suffice to
+produce the immediate assurance. Thus, an angry person is apt to hastily
+accuse another of having done certain things on next to no evidence. The
+love of the marvellous seems to have played a conspicuous part in
+building up and sustaining the fanciful hypotheses which mark the dawn
+of physical science.
+
+Verbal suggestion is a common mode of producing this semblance of a
+recollected event. By means of the narrative style, it vividly suggests
+the idea that the events described belong to the past, and excites the
+imagination to a retrospective construction of them as though they were
+remembered events. Hence the power of works of fiction on the ordinary
+mind. Even when there is no approach to an illusion of perception, or to
+one of memory in the strict sense, the reading of a work of fiction
+begets at the moment a retrospective belief that has a certain
+resemblance to a recollection.
+
+All such illusions as those just illustrated, if not afterwards
+corrected, tend to harden into yet more distinctly "intuitive" errors.
+Thus, for example, one of the crude geological hypotheses, of which Sir
+Charles Lyell tells us,[141] would, by the mere fact of being kept
+before the mind, tend to petrify into a hard fixed belief. And this
+process of hardening is seen strikingly illustrated in the case of
+traditional errors, especially when these fall in with our own emotional
+propensities. Our habitual representations of the remote historical past
+are liable to much the same kind of error as our recollections of early
+personal experience. The wrong statements of others and the promptings
+of our own fancies may lead in the first instance to a filling up of the
+remote past with purely imaginary shapes. Afterwards the particular
+origin of the belief is forgotten, and the assurance assumes the aspect
+of a perfectly intuitive conviction. The hoary traditional myths
+respecting the golden age, and so on, and the persistent errors of
+historians under the sway of a strong emotional bias, illustrate such
+illusions.
+
+So much as to simple illusions of belief, or such as involve single
+representations only. Let us now pass to compound illusions, which
+involve a complex group of representations.
+
+
+B. _Compound Illusory Belief._
+
+A familiar example of a compound belief is the belief in a permanent or
+persistent individual object of a certain character. Such an idea,
+whatever its whole meaning may be--and this is a disputed point in
+philosophy--certainly seems to include a number of particular
+representations, corresponding to direct personal recollections, to the
+recollections of others, and to numerous anticipations of ourselves and
+of others. And if the object be a living creature endowed with feelings,
+our idea of it will contain, in addition to these represented
+perceptions of ourselves or of others, a series of represented insights,
+namely, such as correspond to the inner experience of the being, so far
+as this is known or imagined.
+
+It would thus seem that the idea which we habitually carry about with us
+respecting a complex individual object is a very composite idea. In
+order to see this more fully, let us inquire into what is meant by our
+belief in a person. My idea of a particular friend contains, among other
+things, numbers of vague representations of his habitual modes of
+feeling and acting, and numbers of still more vague expectations of how
+he will or might feel and act in certain circumstances.
+
+Now, it is plain that such a composite idea must have been a very slow
+growth, involving, in certain stages of its formation, numerous
+processes of inference or quasi-inference from the past to the future.
+But in process of time these elements fuse inseparably: the directly
+known and the inferred no longer stand apart in my mind; my whole
+conception of the individual as he has been, is, and will be, seems one
+indivisible cognition; and this cognition is so firmly fixed and
+presents itself so instantaneously to the mind when I think of the
+object, that it has all the appearance of an intuitive conviction.
+
+If this is a fairly accurate description of the structure of these
+compound representations and of their attendant beliefs, it is easy to
+see how many openings for error they cover. To begin with, my
+representation of so complex a thing as a concrete personality must
+always be exceedingly inadequate and fragmentary. I see only a few
+facets of the person's many-sided mind and character. And yet, in
+general, I am not aware of this, but habitually identify my
+representation with the totality of the object.
+
+More than this, a little attention to the process by which these
+compound beliefs arise will disclose the fact that this apparently
+adequate representation of another has arisen in part by other than
+logical processes. If the blending of memory and expectation were simply
+a mingling of facts with correct inferences from these, it might not
+greatly matter; but it is something very different from this. Not only
+has our direct observation of the person been very limited, even that
+which we have been able to see has not been perfectly mirrored in our
+memory. It has already been remarked that recollection is a selective
+process, and this truth is strikingly illustrated in the growth of our
+enduring representations of things. What stamps itself on my memory is
+what surprised me or what deeply interested me at the moment. And then
+there are all the risks of mnemonic illusion to be taken into account as
+well. Thus, my idea of a person, so far even as it is built up on a
+basis of direct personal recollection, is essentially a fragmentary and
+to some extent a misleading representation.
+
+Nor is this all. My habitual idea of a person is a resultant of forces
+of memory conjoined with other forces. Among these are to be reckoned
+the influence of illusory perception or insight, my own and that of
+others. The amount of misinterpretation of the words and actions of a
+single human being during the course of a long acquaintance must be very
+considerable. To these must be added the effect of erroneous single
+expectations and reconstructions of past experiences, in so far as these
+have not been distinctly contradicted and dissipated. All these errors,
+connected with single acts of observing or inferring the feelings and
+doings of another, have their effect in distorting the subsequent total
+representation of the person.
+
+Finally, we must include a more distinct ingredient of active illusion,
+namely, all the complex effects of the activity of imagination as led,
+not by fact and experience, but by feeling and desire. Our permanent
+idea of another reflects all that we have fondly imagined the person
+capable of doing, and thus is made up of an ideal as well as a real
+actually known personality. And this result of spontaneous imagination
+must be taken to include the ideals entertained by others who are likely
+to have influenced us by their beliefs.[142]
+
+Enough has probably been said to show how immensely improbable it is
+that our permanent cognition of so complex an object as a particular
+human being should be at all an accurate representation of the reality,
+how much of the erroneous is certain to get mixed up with the true. And
+this being so, we may say that our apparently simple direct cognition of
+a given person, our assurance of what he is and will continue to be, is
+to some extent illusory.
+
+
+_Illusion of Self-Esteem._
+
+Let us now pass to another case of compound representation, where the
+illusory element is still more striking. I refer to the idea of self
+which each of us habitually carries about with him. Every man's opinion
+of himself, as a whole, is a very complex mental product, in which facts
+known by introspection no doubt play a part, but probably only a very
+subordinate part. It is obvious, from what has been said about the
+structure of our habitual representations of other individuals, that our
+ordinary representation of ourselves will be tinged with that mass of
+error which we have found to be connected with single acts of
+introspection, recollections of past personal experience, and illusory
+single expectations of future personal experiences. How large an opening
+for erroneous conviction here presents itself can only be understood by
+a reference to certain deeply fixed impulses and feelings connected
+with, the very consciousness of self, and favouring what I have marked
+off as active illusion. I shall try to show very briefly that each man's
+intuitive persuasion of his own powers, gifts, or importance--in brief,
+of his own particular value, contains, from the first, a palpable
+ingredient of active illusion.
+
+Most persons, one supposes, have with more or less distinct
+consciousness framed a notion of their own value, if not to the world
+generally, at least to themselves. And this notion, however undefined it
+may be, is held to with a singular tenacity of belief. The greater part
+of mankind, indeed, seem never to entertain the question whether they
+really possess points of excellence. They assume it as a matter
+perfectly self-evident, and appear to believe in their vaguely conceived
+worth on the same immediate testimony of consciousness by which they
+assure themselves of their personal existence. Indeed, the conviction of
+personal consequence may be said to be a constant factor in most men's
+consciousness. However restrained by the rules of polite intercourse, it
+betrays its existence and its energy in innumerable ways. It displays
+itself most triumphantly when the mind is suddenly isolated from other
+minds, when other men unite in heaping neglect and contempt on the
+believer's head. In these moments he proves an almost heroic strength of
+confidence, believing in himself and in his claims to careful
+consideration when all his acquaintance are practically avowing their
+disbelief.
+
+The intensity of this belief in personal value may be observed in very
+different forms. The young woman who, quite independently of others'
+opinion, and even in defiance of it, cherishes a conviction that her
+external attractions have a considerable value; the young man who, in
+the face of general indifference, persists in his habit of voluble talk
+on the supposition that he is conferring on his fellow-creatures the
+fruits of profound wisdom; and the man of years whose opinion of his own
+social importance and moral worth is quite disproportionate to the
+estimation which others form of his claims--these alike illustrate the
+force and pertinacity of the belief.
+
+There are, no doubt, many exceptions to this form of self-appreciation.
+In certain robust minds, but little given to self-reflection, the idea
+of personal value rarely occurs. And then there are timid, sensitive
+natures that betray a tendency to self-distrust of all kinds, and to an
+undue depreciation of personal merit. Yet even here traces of an impulse
+to think well of self will appear to the attentive eye, and one can
+generally recognize that this impulse is only kept down by some other
+stronger force, as, for example, extreme sensitiveness to the judgment
+of others, great conscientiousness, and so on. And however this be, it
+will be allowed that the average man rates himself highly.
+
+It is to be noticed that this persuasion of personal value or excellence
+is, in common, very vague. A man may have a general sense of his own
+importance without in the least being able to say wherein exactly his
+superiority lies. Or, to put it another way, he may have a strong
+conviction that he stands high in the scale of morally deserving
+persons, and yet be unable to define his position more nearly. Commonly,
+the conviction seems to be only definable as an assurance of a
+superlative of which the positive and comparative are suppressed. At
+most, his idea of his moral altitude resolves itself into the
+proposition, "I am a good deal better than Mr. A. or Mr. B." Now, it is
+plain that in these intuitive judgments on his own excellence, the man
+is making an assertion with respect, not only to inner subjective
+feelings which he only can be supposed to know immediately, but also to
+external objective facts which are patent to others, namely, to certain
+active tendencies and capabilities, to the direction of external conduct
+in certain lines.[143] Hence, if the assertion is erroneous, it will be
+in plain contradiction to others' perceptions of his powers or moral
+endowments. And this is what we actually find. A man's self-esteem, in a
+large preponderance of cases, is plainly in excess of others' esteem of
+him. What the man conceives himself to be differs widely from what
+others conceive him to be.
+
+  "Oh wad some power the giftie gie us,
+   To see oursels as others see us!"
+
+Now, whence comes this large and approximately uniform discrepancy
+between our self-esteem and others' esteem of us? By trying to answer
+this question we shall come to understand still better the processes by
+which the most powerful forms of illusion are generated.
+
+It is, I think, a matter of every-day observation that children manifest
+an apparently instinctive disposition to magnify self as soon as the
+vaguest idea of self is reached. It is very hard to define this feeling
+more precisely than by terming it a rudimentary sense of personal
+importance. It may show itself in very different ways, taking now a more
+active form, as an impulse of self-assertion, and a desire to enforce
+one's own will to the suppression of others' wills, and at another time
+wearing the appearance of a passive emotion, an elementary form of
+_amour propre_. And it is this feeling which forms the germ of the
+self-estimation of adults. For in truth all attribution of value
+involves an element of feeling, as respect, and of active desire, and
+the ascription of value to one's self is in its simplest form merely the
+expression of this state of mind.
+
+But how is it, it may be asked, that this feeling shows itself
+instinctively as soon as the idea of self begins to arise in
+consciousness? The answer to this question is to be found, I imagine, in
+the general laws of mental development. All practical judgments like
+that of self-estimation are based on some feeling which is developed
+before it; and, again, the feeling itself is based on some instinctive
+action which, in like manner, is earlier than the feeling. Thus, for
+example, an Englishman's judgment that his native country is of
+paramount value springs out of a long-existent sentiment of patriotism,
+which sentiment again may be regarded as having slowly grown up about
+the half-blindly followed habit of defending and furthering the
+interests of one's nation or tribe. In a similar way, one suspects, the
+feeling of personal worth, with its accompanying judgment, is a product
+of a long process of instinctive action.
+
+What this action is it is scarcely necessary to remind the reader. Every
+living organism strives, or acts as if it consciously strove, to
+maintain its life and promote its well-being. The actions of plants are
+clearly related to the needs of a prosperous existence, individual first
+and serial afterwards. The movements of the lower animals have the same
+end. Thus, on the supposition that man has been slowly evolved from
+lower forms, it is clear that the instinct of self-promotion must be the
+deepest and most ineradicable element of his nature, and it is this
+instinct which directly underlies the rudimentary sentiment of
+self-esteem of which we are now treating.
+
+This instinct will appear, first of all, as the unreflecting organized
+habit of seeking individual good, of aiming at individual happiness, and
+so of pushing on the action of the individual will. This impulse shows
+itself in distinct form as soon as the individual is brought into
+competition with another similarly constituted being. It is the force
+which displays itself in all opposition and hostility, and it tends to
+limit and counteract the gregarious instincts of the race. In the next
+place, as intelligence expands, this instinctive action becomes
+conscious pursuit of an end, and at this stage the thing pursued
+attracts to itself a sentiment. The individual now consciously desires
+his own happiness as contrasted with that of others, knowingly aims at
+enlarging his own sphere of action to the diminution of others' spheres.
+Here we have the nascent sentiment of self-esteem, on which all later
+judgments respecting individual importance are, in part at least,
+founded.
+
+Thus, we see that long before man had arrived at an idea of self there
+had been growing up an emotional predisposition to think well of self.
+And in this way we may understand how it is that this sentiment of
+self-esteem shows itself immediately and instinctively in the child's
+mind as soon as its unfolding consciousness is strong enough to grasp
+the first rough idea of personal existence. Far down, so to speak, below
+the surface of distinct consciousness, in the intricate formation of
+ganglion-cell and nerve-fibre, the connections between the idea of self
+and this emotion of esteem have been slowly woven through long ages of
+animal development.
+
+Here, then, we seem to have the key to the apparently paradoxical fact
+that a man, with all his superior means of studying his own feelings,
+commonly esteems himself, in certain respects at least, less accurately
+than a good external observer would be capable of doing. In forming an
+opinion of ourselves we are exposed to the full force of a powerful
+impulse of feeling. This impulse, acting as a bias, enters more or less
+distinctly into our single acts of introspection, into our attempts to
+recall our past doings, into our insights into the meaning of others'
+words and actions as related to ourselves (forming the natural
+disposition to enjoy flattery), and finally into our wild dreams as to
+our future achievements. It is thus the principal root of that gigantic
+illusion of self-conceit, which has long been recognized by practical
+sense as one of the greatest obstacles to social action; and by art as
+one of the most ludicrous manifestations of human weakness.
+
+If there are all these openings for error in the beliefs we go on
+entertaining respecting individual things, including ourselves, there
+must be a yet larger number of such openings in those still more
+compound beliefs which we habitually hold respecting collections or
+classes of things. A single illusion of perception or of memory may
+suffice to give rise to a wholly illusory belief in a class of objects,
+for example, ghosts. The superstitious beliefs of mankind abundantly
+illustrate this complexity of the sources of error. And in the case of
+our every-day beliefs respecting real classes of objects, these sources
+contribute a considerable quota of error. We may again see this by
+examining our ordinary beliefs respecting our fellow-men.
+
+A moment's consideration will show that our prevailing views respecting
+any section of mankind, say our fellow-countrymen, or mankind at large,
+correspond at best to a very loose process of reasoning. The accidents
+of our personal experience and opportunities of observation, the
+traditions which coloured our first ideas, the influence of our dominant
+feelings in selecting for attention and retention certain aspects of the
+complex object, and in idealizing this object,--these sources of passive
+and active illusion, must, to say the least, have had as much to do with
+our present solidified and seemingly "intuitive" knowledge as anything
+that can be called the exercise of individual judgment and reasoning
+power.
+
+The force of this observation and the proof that such widely generalized
+beliefs are in part illusory, is seen in the fact that men of unlike
+experience and unlike temperament form such utterly dissimilar views of
+the same object. Thus, as Mr. Spencer has shown,[144] in looking at
+things national there may be not only a powerful patriotic bias at work
+in the case of the vulgar Philistine, but also a distinctly
+anti-patriotic bias in the case of the over-fastidious seeker after
+culture. And I need hardly add that the different estimates of mankind
+held with equal assurance by the cynic, the misanthropist, and the
+philanthropic vindicator of his species, illustrate a like diversity of
+the psychological conditions of belief.
+
+Finally, illusion may enter into that still wider collection of beliefs
+which make up our ordinary views of life and the world as a whole. Here
+there reflect themselves in the plainest manner the accidents of our
+individual experience and the peculiar errors to which our intellectual
+and emotional conformation disposes us. The world is for us what we feel
+it to be; and we feel it to be the cause of our particular emotional
+experience. Just as we have found that our environment helps to
+determine our idea of self and personal continuity, so, conversely, our
+inner experience, our remembered or imagined joys and sorrows throw a
+reflection on the outer world, giving it its degree of worth. Hence the
+contradictory, and consequently to some extent at least illusory, views
+of the optimist and the pessimist, "intuitions" which, I have tried to
+show elsewhere, are connected with deeply rooted habits of feeling, and
+are antecedent to all reasoned philosophic systems.
+
+If proof were yet wanted that these wide-embracing beliefs may to some
+extent be illusory, it would be found in the fact that they can be
+distinctly coloured by a temporary mood or mental tone. As I have more
+than once had occasion to remark, a feeling when present tends to colour
+all the ideas of the time. And when out of sorts, moody, and
+discontented, a man is prone to find a large objective cause of his
+dissatisfaction in a world out of joint and not moving to his mind.
+
+It is evident that all the permanent beliefs touched on in this chapter
+must constitute powerful predispositions with respect to any particular
+act of perception, insight, introspection, or recollection. In other
+words, these persistent beliefs, so far as individual or personal, are
+but another name for those fixed habits of mind which, in the case of
+each one of us, constitute our intellectual bias, and the source of the
+error known as personal equation. And it may be added that, just as
+these erroneous beliefs existing in the shape of fixed prejudices
+constitute a bias to new error, so they act as powerful resisting forces
+in relation to new truth and the correction of error.
+
+In comparing these illusions of belief with those of perception and
+memory, we cannot fail to notice their greater compass or range, in
+other words, the greater extent of the region of fact misrepresented.
+Even if they are less forcible and irresistible than these errors, they
+clearly make up for this by the area which they cover.
+
+Another thing to be observed with respect to these comprehensive beliefs
+is that where, as here, so many co-operant conditions are at work, the
+whole amount of common objective agreement is greatly reduced. In other
+words, individual peculiarities of intellectual conformation, emotional
+temperament, and experience have a far wider scope for their influence
+in these beliefs than they have in the case of presentative cognitions.
+At the same time, it is noteworthy that error much more rapidly
+propagates itself here than in the case of our perceptions or
+recollections. As we have seen, these beliefs all include much more than
+the results of the individual's own experience. They offer a large field
+for the influence of personal ascendency, of the contagion of sympathy,
+and of authority and tradition. As a consequence of this, the illusions
+of belief are likely to be far more persistent than those of perception
+or of memory; for not only do they lose that salutary process of
+correction which comparison with the experience of others affords, but
+they may even be strengthened and upheld to some extent by such social
+influences.
+
+And here the question might seem to obtrude itself, whether, in relation
+to such a fluctuating mass of belief as that just reviewed, in which
+there appears to be so little common agreement, we can correctly speak
+of anything as objectively determinable. If illusion and error as a
+whole are defined by a reference to what is commonly held true and
+certain, what, it may be asked, becomes of the so-called illusions of
+belief?
+
+This question will have to be fully dealt with in the following chapter.
+Here it may be sufficient to remark that amid all this apparent
+deviation of belief from a common standard of truth, there is a clear
+tendency to a rational consensus. Thought, by disengaging what is really
+matter of permanent and common cognition, both in the individual and
+still more in the class,[145] and fixing this quantum of common
+cognition in the shape of accurate definitions and universal
+propositions, is ever fighting against and restraining the impulses of
+individual imagination towards dissociation and isolation of belief. And
+this same process of scientific control of belief is ever tending to
+correct widespread traditional forms of error, and to erect a new and
+better standard of common cognition.
+
+This scientific regulation of belief only fails where the experiences
+which underlie the conceptions are individual, variable, and subjective.
+Hence there is no definite common conception of the value of life and of
+the world, just because the estimate of this value must vary with
+individual circumstances, temperament, etc. All that can be looked for
+here in the way of a common standard or norm is a rough average
+estimate. And this common-sense judgment serves practically as a
+sufficient criterion of truth, at least in relation to such extreme
+one-sidedness of view as approaches the abnormal, that is to say, one of
+the two poles of irrational exaltation, or "joy-madness," and abject
+melancholy, which, appear among the phenomena of mental disease.[146]
+
+
+
+
+CHAPTER XII.
+
+RESULTS.
+
+
+The foregoing study of illusions may not improbably have had a
+bewildering effect on the mind of the reader. To keep the mental eye,
+like the bodily eye, for any time intently fixed on one object is apt to
+produce a feeling of giddiness. And in the case of a subject like
+illusion, the effect is enormously increased by the disturbing character
+of the object looked at. Indeed, the first feeling produced by our
+survey of the wide field of illusory error might be expressed pretty
+accurately by the despondent cry of the poet--
+
+  "Alas! it is delusion all:
+   The future cheats us from afar,
+   Nor can we be what we recall,
+   Nor dare we think on what we are."
+
+It must be confessed that our study has tended to bring home to the mind
+the wide range of the illusory and unreal in our intellectual life. In
+sense-perception, in the introspection of the mind's own feelings, in
+the reading of others' feelings, in memory, and finally in belief, we
+have found a large field for illusory cognition. And while illusion has
+thus so great a depth in the individual mind, it has a no less striking
+breadth or extent in the collective human mind. No doubt its grosser
+forms manifest themselves most conspicuously in the undisciplined mind
+of the savage and the rustic; yet even the cultivated mind is by no
+means free from its control. In truth, most of the illusions illustrated
+in this work are such as can be shared in by all classes of mind.
+
+In view of this wide far-reaching area of ascertained error, the mind
+naturally asks, What are the real limits of illusory cognition, and how
+can we be ever sure of having got beyond them? This question leads us on
+to philosophical problems of the greatest consequence, problems which
+can only be very lightly touched in this place. Before approaching
+these, let us look back a little more carefully and gather up our
+results, reflect on the method which we have been unconsciously
+adopting, and inquire how far this scientific mode of procedure will
+take us in determining what is the whole range of illusory cognition.
+
+We have found an ingredient of illusion mixed up with all the popularly
+recognized forms of immediate knowledge. Yet this ingredient is not
+equally conspicuous in all cases. First of all, illusion varies very
+considerably in its degree of force and persistence. Thus, in general, a
+presentative illusion is more coercive than a representative; an
+apparent reality present to the mind is naturally felt to be more
+indubitable than one absent and only represented. On the other hand, a
+representative illusion is often more enduring than a presentative, that
+is to say, less easily found out. It is to be added that a good deal of
+illusion is only partial, there being throughout an under-current of
+rational consciousness, a gentle play of self-criticism, which keeps the
+error from developing into a perfect self-delusion. This remark applies
+not only to the innocent illusions of art, but also to many of our
+every-day illusions, both presentative and representative. In many
+cases, indeed, as, for example, in looking at a reflection in a mirror,
+the illusion is very imperfect, remaining in the nascent stage.
+
+Again, a little attention to the facts here brought together will show
+that the proportion of illusory to real knowledge is far from being the
+same in each class of immediate or quasi-immediate cognition. Thus, with
+respect to the great distinction between presentative and representative
+knowledge, it is to be observed that, in so far as any act of cognition
+is, strictly speaking, presentative, it does not appear to admit of
+error. The illusions of perception are connected with the representative
+side of the process, and are numerous just because this is so extensive.
+On the other hand, in introspection, where the scope of independent
+representation is so limited, the amount of illusion is very
+inconsiderable, and may in practice be disregarded. So again, to take a
+narrower group of illusions, we find that in the recalling of distant
+events the proportion of error is vastly greater than in the recalling
+of near events.
+
+So much as to the extent of illusion as brought to light by our
+preceding study. Let us now glance at the conclusions obtained
+respecting its nature and its causes.
+
+_Causes of Illusion._
+
+Looking at illusion as a whole, and abstracting from the differences of
+mental mechanism in the processes of perception, memory, etc., we may
+say that the _rationale_ or mode of genesis of illusion is very much the
+same throughout. Speaking broadly, one may describe all knowledge as a
+correspondence of representation with fact or experience, or as a stable
+condition of the representation which cannot be disturbed by new
+experiences. It does not matter, for our present purpose, whether the
+fact represented is supposed to be directly present, as in presentative
+cognition; or to be absent, either as something past or future, or
+finally as a "general fact," that is to say, the group of facts (past
+and future) embodied in a universal proposition.[147]
+
+In general this accordance between our representations and facts is
+secured by the laws of our intellectual mechanism. It follows from the
+principles of association that our simple experiences, external and
+internal, will tend to reflect themselves in perception, memory,
+expectation, and general belief, in the very time-connections in which
+they actually occur. To put it briefly, facts which occur together will
+in general be represented together, and they will be the more perfectly
+co-represented in proportion to the frequency of this concurrence.
+
+Illusion, as distinguished from correct knowledge, is, to put it
+broadly, deviation of representation from fact. This is due in part to
+limitations and defects in the intellectual mechanism itself, such as
+the imperfections of the activities of attention, discrimination, and
+comparison, in relation to what is present. Still more is it due to the
+control of our mental processes by association and habit. These forces,
+which are at the very root of intelligence, are also, in a sense, the
+originators of error. Through the accidents of our experience or the
+momentary condition of our reproductive power, representations get
+wrongly grouped with presentations and with one another; wrongly
+grouped, that is to say, according to a perfect or ideal standard,
+namely, that the grouping should always exactly agree with the order of
+experience as a whole, and the force of cohesion be proportionate to the
+number of the conjunctions of this experience.
+
+This great source of error has been so abundantly illustrated under the
+head of Passive Illusions that I need not dwell on it further. It is
+plain that a passive error of perception, or of expectation, is due in
+general to a defective grouping of elements, to a grouping which
+answers, perhaps, to the run of the individual's actual experience, but
+not to a large and complete common experience.[148] Similarly, an
+illusory general belief is plainly a welding together of elements (here
+concepts, answering to innumerable representative images) in
+disagreement with the permanent connections of experience. Even a
+passive illusion of memory, in so far as it involves a rearrangement of
+successive representations, shows the same kind of defect.
+
+In the second place, this incorrect grouping maybe due, not to defects
+in attention and discrimination, combined with insufficiently grounded
+association, but to the independent play of constructive imagination and
+the caprices of feeling. This is illustrated in what I have called
+Active Illusions, whether the excited perceptions and the hallucinations
+of sense, or the fanciful projections of memory or of expectation. Here
+we have a force directly opposed to that of experience. Active illusion
+arises, not through the imperfections of the intellectual mechanism, but
+through a palpable interference with this mechanism. It is a regrouping
+of elements which simulates the form of a suggestion by experience, but
+is, in reality, the outcome of the individual mind's extra-intellectual
+impulses.
+
+We see, then, that, in spite of obvious differences in the form, the
+process in all kinds of immediate cognition is fundamentally identical.
+It is essentially a bringing together of elements, whether similar or
+dissimilar and associated by a link of contiguity, and a viewing of
+these as connected parts, of a whole; it is a process of synthesis. And
+illusion, in all its forms, is bad grouping or carelessly performed
+synthesis. This holds good even of the simplest kinds of error in which
+a presentative element is wrongly classed; and it holds good of those
+more conspicuous errors of perception, memory, expectation, and compound
+belief, in which representations connect themselves in an order not
+perfectly answering to the objective order.
+
+This view of the nature and causes of illusion is clearly capable of
+being expressed in physical language. Bad grouping of psychical elements
+is equivalent to imperfect co-ordination of their physical, that is to
+say, nervous, conditions, imperfect in the evolutionist's sense, as not
+exactly according with external relations. So far as illusions of
+suggestion (passive illusions) are concerned, the error is connected
+with organized tendencies, due to a limited action of experience. On the
+other hand, illusions of preconception (active illusions) usually
+involve no such deeply fixed or permanent organic connections, but
+merely a temporary confluence of nerve-processes.[149] The nature of the
+physical process is best studied in the case of errors of
+sense-perception. Yet we may hypothetically argue that even in the case
+of the most complex errors, as those of memory and of belief, there is
+implied a deviation in the mode of connection of nervous structures
+(whether the connection be permanent or temporary) from the external
+order of facts.
+
+And now we are in a position to see whether illusion is ultimately
+distinguishable from other modes of error, namely, those incident to
+conscious processes of reasoning. It must have been plain to an
+attentive reader throughout our exposition that, in spite of our
+provisional distinction, no sharp line can be drawn between much of
+what, on the surface, looks like immediate knowledge, and consciously
+derived or inferred knowledge. On its objective side, reasoning may be
+roughly defined as a conscious transition of mind from certain facts or
+relations of facts to other facts or relations recognized as similar.
+According to this definition, a fallacy would be a hasty, unwarranted
+transition to new cases not identical with the old. And a good part of
+immediate knowledge is fundamentally the same, only that here, through
+the exceptional force of association and habit, the transition is too
+rapid to be consciously recognized. Consequently, illusion becomes
+identified at bottom with fallacious inference: it may be briefly
+described as collapsed inference. Thus, illusory perception and
+expectation are plainly a hasty transition of mind from old to new, from
+past to present, conjunctions of experience.[150] And, as we have seen,
+an illusory general belief owes its existence to a coalescence of
+representations of known facts or connections with products of
+imagination which simulate the appearance of inferences from these
+facts.
+
+In the case of memory, in so far as it is not aided by reasoning from
+present signs, there seems to be nothing like a movement of inference.
+It is evident, indeed, that memory is involved in and underlies every
+such transition of thought. Illusions of memory illustrate rather a
+process of wrong classing, that is to say, of wrongly identifying the
+present mental image with past fact, which is the initial step in all
+inference. In this way they closely resemble those slight errors of
+perception which are due to erroneous classing of sense-impressions. But
+since the intellectual process involved in assimilating mental elements
+is very similar to that implied in assimilating complex groups of such
+elements, we may say that even in these simple kinds of error there is
+something which resembles a wrong classing of relations, something,
+therefore, which approximates in character to a fallacy.
+
+By help of this brief review of the nature and causes of illusion, we
+see that in general it may be spoken of as deviation of individual from
+common experience. This applies to passive illusion in so far as it
+follows from the accidents of individual experience, and it still more
+obviously applies to active illusion as due to the vagaries of
+individual feeling and constructive imagination. We might, perhaps,
+characterize all illusion as partial view, partial both in the sense of
+being incomplete, and in the other sense of being that to which the mind
+by its peculiar predispositions inclines. This being so, we may very
+roughly describe all illusion as abnormal. Just as hallucination, the
+most signal instance of illusion, is distinctly on the border-land of
+healthy and unhealthy mental life; just as dreams are in the direction
+of such unhealthy mental action; so the lesser illusions of memory and
+so on are abnormal in the sense that they imply a departure from a
+common typical mode of intellectual action.
+
+It is plain, indeed, that this is the position we have been, taking up
+throughout our discussion of illusion. We have assumed that what is
+common and normal is true, or answers to what is objectively real. Thus,
+in dealing with errors of perception, we took for granted that the
+common percept--meaning by this what is permanent in the individual and
+the general experience--is at the same time the true percept. So in
+discussing the illusions of memory we estimated objective time by the
+judgment of the average man, free from individual bias, and apart from
+special circumstances favourable to error. Similarly, in the case of
+belief, true belief was held to be that which men in general, or in the
+long run, or on the average, hold true, as distinguished from what the
+individual under variable and accidental influences holds true. And even
+in the case of introspection we found that true cognition resolved
+itself into a consensus or agreement as to certain psychical facts.
+
+
+_Criterion of Illusion._
+
+Now, it behoves us here to examine this assumption, with the view of
+seeing how far it is perfectly sound. For it may be that what is
+commonly held true does not in all cases strictly answer to the real, in
+which case our idea of illusion would have to be extended so as to
+include certain common beliefs. This question was partly opened up at
+the close of the last chapter. It will be found that the full
+discussion of it carries us beyond the scientific point of view
+altogether. For the present, however, let us see what can be said about
+it from that standpoint of positive science to which we have hitherto
+been keeping.
+
+Now, if by common be meant what has been shared by all minds or the
+majority of minds up to a particular time, a moment's inspection of the
+process of correcting illusion will show that science assumes the
+possibility of a common illusion. In the history of discovery, the first
+assault on an error was the setting up of the individual against the
+society. The men who first dared to say that the sun did not move round
+the earth found to their cost what it was to fly in the face of a
+common, though illusory, perception of the senses.[151]
+
+If, however, by common be understood what is permanently and unshakably
+held true by men in proportion as their minds become enlightened, then
+science certainly does assume the truth of common perception and belief.
+Thus, the progress of the physical sciences may be described as a
+movement towards a new, higher, and more stable consensus of ideas and
+beliefs. In point of fact, the truths accepted by men of science already
+form a body of common belief for those who are supposed by all to have
+the means of testing the value of their convictions. And the same
+applies to the successive improvements in the conceptions of the moral
+sciences, for example, history and psychology. Indeed, the very meaning
+of science appears to be a body of common cognition to which all minds
+converge in proportion to their capabilities and opportunities of
+studying the particular subject-matter concerned.
+
+Not only so, from a strictly scientific point of view it might seem
+possible to prove that common cognition, as defined above, must in
+general be true cognition. I refer here to the now familiar method of
+the evolutionist.
+
+According to this doctrine, which is a scientific method in so far as it
+investigates the historical developments of mind or the order of mental
+phenomena in time, cognition may be viewed as a part of the result of
+the interaction of external agencies and the organism, as an incident of
+the great process of adaptation, physical and psychical, of organism to
+environment. In thus looking at cognition, the evolutionist is making
+the assumption which all science makes, namely, that correct views are
+correspondences between internal (mental) relations and external
+(physical) relations, incorrect views disagreements between these
+relations. From this point of view he may proceed to argue that the
+intellectual processes must tend to conform to external facts. All
+correspondence, he tells us, means fitness to external conditions and
+practical efficiency, all want of correspondence practical incompetence.
+Consequently, those individuals in whom the correspondence was more
+complete and exact would have an advantage in the struggle for existence
+and so tend to be preserved. In this way the process of natural
+selection, by separately adjusting individual representations to
+actualities, would make them converge towards a common meeting-point or
+social standard of true cognition. That is to say, by eliminating or at
+least greatly circumscribing the region of individual illusion, natural
+selection would exclude the possibility of a persistent common illusion.
+
+Not only so, the evolutionist may say that this coincidence between
+common beliefs and true beliefs would be furthered by social as well as
+individual competition. A community has an advantage in the struggle
+with other communities when it is distinguished by the presence of the
+conditions of effective co-operation, such as mutual confidence. Among
+these conditions a body of true knowledge seems to be of the first
+importance, since conjoint action always presupposes common beliefs,
+and, to be effective action, implies that these beliefs are correct.
+Consequently, it may be argued, the forces at work in the action of man
+on man, of society on the individual, in the way of assimilating belief,
+must tend, in the long run, to bring about a coincidence between
+representations and facts. Thus, in another way, natural selection would
+help to adjust our ideas to realities, and to exclude the possibility of
+anything like a permanent common error.
+
+Yet once more, according to Mr. Herbert Spencer, the tendency to
+agreement between our ideas and the environment would be aided by what
+he calls the direct process of adaptation. The exercise of a function
+tends to the development of that function. Thus, our acts of perception
+must become more exact by mere repetition. So, too, the representations
+and concepts growing out of perceptions must tend to approximate to
+external facts by the direct action of the environment on our physical
+and psychical organism; for external relations which are permanent will,
+in the long run, stamp themselves on our nervous and mental structure
+more deeply and indelibly than relations which are variable and
+accidental.
+
+It would seem, from all this, that so long as we are keeping to the
+scientific point of view, that is to say, taking for granted that there
+is something objectively real answering to our perceptions and
+conceptions, the question of the possibility of a universal or
+(permanently) common illusion does not arise. Yet a little more
+reflection will show us that it may arise in a way. So far as the
+logical sufficiency of the social consensus or common belief is accepted
+as scientifically proved, it is open to suspicion on strictly scientific
+grounds. The evolutionist's proof involves one or two assumptions which
+are not exactly true.
+
+In the first place, it is not strictly correct to say that all illusion
+involves a practical unfitness to circumstances. At the close of our
+investigation of particular groups of illusion, for example, those of
+perception and memory, it was pointed out that many of the errors
+reviewed were practically harmless, being either momentary and
+evanescent, or of such a character as not to lead to injurious action.
+And now, by glancing back over the field of illusion as a whole, we may
+see the same thing. The day-dreams in which some people are apt to
+indulge respecting the remote future have little effect on their
+conduct. So, too, a man's general view of the world is often unrelated
+to his daily habits of life. It seems to matter exceedingly little, in
+general, whether a person take up the geocentric or the heliocentric
+conception of the cosmic structure, or even whether he adopt an
+optimistic or pessimistic view of life and its capabilities.
+
+So inadequate, indeed, does the agency of natural selection seem to be
+to eliminate illusion, that it may even be asked whether its tendency
+may not be sometimes to harden and fix rather than to dissolve and
+dissipate illusory ideas and beliefs. It will at once occur to the
+reader that the illusion of self-esteem, discussed in the last chapter,
+may have been highly useful as subserving individual self-preservation.
+In a similar way, it has been suggested by Schopenhauer that the
+illusion of the lover owes its force and historical persistence to its
+paramount utility for the preservation of the species. And to pass from
+a recurring individual to a permanently common belief, it is maintained
+by the same pessimist and his followers that what they regard as the
+illusion of optimism, namely, the idea that human life as a whole is
+good, grows out of the individual's irrational love of life, which is
+only the same instinctive impulse of self-preservation appearing as
+conscious desire. Once more, it has been suggested that the belief in
+free-will, even if illusory, would be preserved by the process of
+evolution, owing to its paramount utility in certain stages of moral
+development. All this seems to show at least the possibility of a kind
+of illusion which would tend to perpetuate itself, and to appear as a
+permanent common belief.
+
+Now, so far as this is the case, so far as illusion is useful or only
+harmless, natural selection cannot, it is plain, be counted on to weed
+it out, keeping it within the narrow limits of the exceptional and
+individual. Natural selection gets rid of what is harmful only, and is
+indifferent to what is practically harmless.
+
+It may, however, still be said that the process of direct adaptation
+must tend to establish such a consensus of true belief. Now, I do not
+wish for a moment to dispute that the growth of intelligence by the
+continual exercise of its functions tends to such a consensus: this is
+assumed to be the case by everybody. What I want to point out is that
+there is no scientific proof of this position.
+
+The correspondence of internal to external relations is obviously
+limited by the modes of action of the environment on the organism,
+consequently by the structure of the organism itself. Scientific men are
+familiar with the idea that there may be forces in the environment which
+are practically inoperative on the organism, there being no
+corresponding mode of sensibility. And even if it be said that our
+present knowledge of the material world, including the doctrine of the
+conservation of energy, enables us to assert that there is no mode of
+force wholly unknown to us, it can still be contended that the
+environment may, for aught we know, be vastly more than the forces of
+which, owing to the nature of our organism, we know it to be composed.
+In short, since, on the evolution theory viewed as a scientific
+doctrine, the real external world does not directly mirror itself in our
+minds, but only indirectly brings our perceptions and representations
+into adjustment by bringing into adjustment the nervous organism with
+which they are somehow connected, it is plain that we cannot be certain
+of adequately apprehending the external reality which is here assumed to
+exist.
+
+Science, then, cannot prove, but must assume the coincidence between
+permanent common intuitions and objective reality. To raise the question
+whether this coincidence is perfect or imperfect, whether all common
+intuitions known to be persistent are true or whether there are any that
+are illusory, is to pass beyond the scientific point of view to another,
+namely, the philosophic. Thus, our study of illusion naturally carries
+us on from scientific to philosophic reflection. Let me try to make this
+still more clear.
+
+
+_Transition to Philosophic View._
+
+All science makes certain assumptions which it never examines. Thus, the
+physicist assumes that when we experience a sensation we are acted on by
+some pre-existing external object which is the cause, or at least one
+condition, of the sensation. While resolving the secondary qualities of
+light, sound, etc., into modes of motion, while representing the object
+very differently from the unscientific mind, he agrees with this in
+holding to the reality of something external, regarding this as
+antecedent to and therefore as independent of the particular mind which
+receives the sense-impression. Again, he assumes the uniformity of
+nature, the universality of the causal relation, and so on.
+
+Similarly, the modern psychologist, when confining himself within the
+limits of positive science, and treating mind phenomenally or
+empirically, or, in other words, tracing the order of mental states in
+time and assigning their conditions, takes for granted much the same as
+physical science does. Thus, as our foregoing analysis of perception
+shows, he assumes that there is an external cause of our sensations,
+that there are material bodies in space, which act on our sense-organs
+and so serve as the condition of our sense-impressions. More than this,
+he regards, in the way that has been illustrated in this work, the
+percept itself, in so far as it is a process in time, as the normal
+result of the action of such external agents on our nerve-structures, in
+other words, as the effect of such action in the case of the healthy and
+perfect nervous organism with the average organized dispositions,
+physical and psychical; in which case he supposes the percept to
+correspond, in certain respects at least, with the external cause as
+made known by physical science. And, on the other hand, he looks on a
+false or illusory percept as arising in another way not involving, as
+its condition, the pre-existence of a corresponding material body or
+physical agent. And in this view of perception, as of other mental
+phenomena, the psychologist clearly takes for granted the principle that
+all mental events conform to the law of causation. Further, he assumes
+that the individual mind is somehow, in a way which it is not his
+province to inquire into, one and the same throughout, and so on.
+
+The doctrine of evolution, too, in so far as scientific--that is, aiming
+at giving an account of the historical and pre-historical developments
+of the collective mind in time--agrees with psychology in making like
+assumptions. Thus, it conceives an external agency (the environment) as
+the cause of our common sensations and perceptions. That is to say, it
+represents the external world as somehow antecedent to, and so
+apparently independent of, the perceptions which are adjusted to it. And
+all this shows that science, while removed from vulgar unenlightened
+opinion, takes sides with popular thought in assuming the truth of
+certain fundamental ideas or so-called intuitive beliefs, into the exact
+meaning of which it does not inquire.
+
+When the meaning of these assumptions is investigated, we pass out of
+the scientific into the philosophic domain. Philosophy has to critically
+investigate the data of popular thought and of science. It has to
+discover exactly what is implied in these fundamental principles. Then
+it has to test their value by erecting a final criterion of truth, by
+probing the structure of cognition to the bottom, and determining the
+proper organ of certain or accurate knowledge; or, to put it another
+way, it has to examine what is meant by reality, whether there is
+anything real independently of the mind, and if so, what. In doing this
+it inquires not only what common sense means by its object-world clothed
+in its variegated garment of secondary qualities, its beauty, and so on,
+but also what physical science means by its cosmic mechanism of sensible
+and extra-sensible matter in motion: whether there is any kind of
+objective reality belonging to the latter which does not also belong to
+the former; and how the two worlds are related one to another. That is
+to say, he asks whether the bodies in space assumed to exist by the
+physicist as the antecedent conditions of particular sensations and
+percepts are independent of mind and perception generally.[152]
+
+In doing all this, philosophy is theoretically free to upset as much of
+popular belief of the persistent kind as it likes. Nor can science find
+fault with it so long as it keeps to its own sphere, and does not
+directly contradict any truth which science, by the methods proper to
+it, is able to establish. Thus, for example, if philosophy finds that
+there is nothing real independently of mind, science will be satisfied
+so long as it finds a meaning for its assumed entities, such as space,
+external things, and physical causes.[153]
+
+The student of philosophy need not be told that these imposing-looking
+problems respecting cognition, making, up what the Germans call the
+"Theory of Cognition," and the cognate problem respecting the nature of
+reality, are still a long way from being settled. To-day, as in the days
+of Plato and Aristotle, are argued, in slightly altered forms, the vexed
+questions, What is true cognition? Is it a mere efflux from sensation,
+a passive conformity of representation to sensation (sensualism or
+empiricism)? or is it, on the other hand, a construction of active
+thought, involving certain necessary forms of intelligence (rationalism
+or intuitivism)?
+
+Again, how are we to shape to ourselves real objective existence? Is it
+something wholly independent of the mind (realism)? and if so, is this
+known to be what we--meaning here common people and men of science
+alike--represent it as being (natural realism), or something different
+(transfigured realism)? Or is it, on the contrary, something involving
+mind (idealism)? and if so, is it a strictly phenomenal distinction
+within our conscious experience (empirical idealism, phenomenalism), or
+one of the two poles of subject and object constituted by every act of
+thought (rational idealism)? These are some of the questions in
+philosophy which still await their final answer.
+
+Philosophy being thus still a question and not a solution, we need not
+here trouble ourselves about its problems further than to remark on
+their close connection with our special subject, the study of illusion.
+
+Our brief reference to some of the principal inquiries of philosophy
+shows that it tends to throw doubt on things which the unreflecting
+popular mind holds to be indubitable. Different schools of philosophy
+have shown themselves unequally concerned about these so-called
+intuitive certainties. In general it may be said that philosophy,
+though, as I have remarked, theoretically free to set up its own
+standard of certainty, has in practice endeavoured to give a meaning
+to, and to find a justification for the assumptions or first principles
+of science. On the other hand, it has not hesitated, when occasion
+required, to make very light of the intuitive beliefs of the popular
+mind as interpreted by itself. Thus, rationalists of the Platonic type
+have not shrunk from pronouncing individual impressions and objects
+illusory, an assertion which certainly seems to be opposed to the
+assumptions of common sense, if not to those of science. On the other
+hand, the modern empirical or association school is quite ready to
+declare that the vulgar belief in an external world, so far as it
+represents this as independent of mind,[154] is an illusion; that the
+so-called necessary beliefs respecting identity, uniformity, causation,
+etc., are not, strictly speaking, necessary; and so on. And in these
+ways it certainly seems to come into conflict with popular convictions,
+or intuitive certainties, as they present themselves to the unreflecting
+intelligence.
+
+Philosophy seems, then, to be a continuation of that process of
+detecting illusion with which science in part concerns itself. Indeed,
+it is evident that our special study has a very close connection with
+the philosophic inquiry. What philosophy wants is something intuitively
+certain as its starting-point, some _point d'appui_ for its
+construction. The errors incident to the process of reasoning do not
+greatly trouble it, since these can, in general, be guarded against by
+the rules of logic. But error in the midst of what, on the face of it,
+looks like intuitive knowledge naturally raises the question, Is there
+any kind of absolutely certain cognition, any organ for the accurate
+perception of truth? And this intimate relation between the scientific
+and the philosophic consideration of illusion is abundantly illustrated
+in the history of philosophy. The errors of sense, appearing in a region
+which to the vulgar seems so indubitable, have again and again set men
+thinking on the question, "What is the whole range of illusion? Is
+perception, as popularly understood, after all, a big hallucination? Is
+our life a dream?"[155]
+
+On the other hand, if our study of the wide range of illusion is fitted
+to induce that temper of mind which is said to be the beginning of
+philosophy, that attitude of universal doubt expressed by Descartes in
+his famous maxim, _De omnibus dubitandum_, a consideration of the
+process of correction is fitted to lead the mind on to the determination
+of the conditions of accurate knowledge. It is evident, indeed, that the
+very conception of an illusion implies a criterion of certainty: to call
+a thing illusory, is to judge it by reference to some accepted standard
+of truth.
+
+The mental processes involved in detecting, resisting, and overcoming
+illusion, are a very interesting subject for the psychologist, though we
+have not space here to investigate them fully. Turning to presentative,
+and more particularly sense-illusions, we find that the detection of an
+illusion takes place now by an appeal from one sense to another, for
+example, from sight to touch, by way of verification;[156] now (as in
+Myer's experiment) by a reference from sense and presentation altogether
+to representation or remembered experience and a process of reasoning;
+and now, (as in the illusions of art) conversely, by a transition of
+mind from what is suggested to the actual sense-impression of the
+moment. In the sphere of memory, again, illusion is determined, as such,
+now by attending more carefully to the contents of memory, now by a
+process of reasoning from some presentative cognition. Finally, errors
+in our comprehensive general representations of things are known to be
+such partly by reasoning from other conceptions, and partly by a
+continual process of reduction of representation to presentation, the
+general to the particular. I may add that the correction of illusion by
+an act of reflection and reasoning, which brings the part into
+consistent relation with the whole of experience, includes throughout
+the comparison of the individual with the collective or social
+experience.[157]
+
+We may, perhaps, roughly summarize these operations by saying that they
+consist in the control of the lower automatic processes (association or
+suggestion) by the higher activities of conscious will. This activity of
+will takes the form now of an effort of attention to what is directly
+present to the mind (sense-impression, internal feeling, mnemonic image,
+etc.), now of conscious reflection, judgment, and reasoning, by which
+the error is brought into relation to our experience as a whole,
+individual and collective.
+
+It is for the philosopher to investigate the inmost nature of these
+operations as they exhibit themselves in our every-day individual
+experience, and in the large intellectual movements of history. In no
+better way can he arrive at what common sense and science regard as
+certain cognition, at the kinds of knowledge on which they are wont to
+rely most unhesitatingly.
+
+There is one other relation of our subject to philosophic problems which
+I have purposely left for final consideration. Our study has consisted
+mainly in the psychological analysis of illusions supposed to be known
+or capable of being known as such. Now, the modern association school
+professes to be able to resolve some of the so-called intuitions of
+common sense into elements exactly similar to those into which we have
+here been resolving what are acknowledged by all as illusions. This fact
+would seem to point to a close connection between the scientific study
+of illusion and the particular view of these fundamental intuitions
+taken by one philosophic school. In order to see whether there is really
+this connection, we must reflect a little further on the nature of the
+method which we have been pursuing.
+
+I have already had occasion to rise the expression "scientific
+psychology," or psychology as a positive science, and the meaning of
+this expression must now be more carefully considered. As a positive
+science, psychology is limited to the function of analyzing mental
+states, and of tracing their origin in previous and more simple mental
+states. It has, strictly speaking, nothing to do with the question of
+the legitimacy or validity of any mental act.
+
+Take a percept, for example. Psychology can trace its parentage in
+sensation, the mode in which it has come by its contents in the laws of
+association. But by common consent, a percept implies a presentative
+apprehension of an object now present to sense. Is this valid or
+illusory? This question psychology, as science, does not attempt to
+answer. It would not, I conceive, answer it even if it were able to make
+out that the whole mental content in the percept can be traced back to
+elementary sensations and their combinations. For the fact that in the
+chemistry of mind elements may combine in perfectly new forms does not
+disprove that the forms thus arising, whether sentiments or
+quasi-cognitions, are invalid. Much less can psychology dispute the
+validity of a percept if it cannot be sure that the mind adds nothing to
+sensation and its grouping; that in the genesis of the perceptive state,
+with its intuition of something external and now present as object,
+nothing like a form of intelligence is superimposed on the elements of
+sensation, giving to the result of their coalescence the particular
+unity which we find. Whether psychology as a positive science can ever
+be sure of this: whether, that is to say, it can answer the question,
+"How do we come by the idea of object?" without assuming some particular
+philosophic or extra-scientific theory respecting the ultimate nature of
+mind, is a point which I purposely leave open.
+
+I would contend, then, that the psychologist, in tracing the genesis of
+the percept out of previous mental experiences, no more settles the
+question, What is the object of perception? than the physicist settles
+it in referring the sense-impression (and so the percept) to a present
+material agent as its condition.
+
+The same applies to our idea of self. I may discover the concrete
+experiences which supply the filling in of the idea, and yet not settle
+the question, Does intelligence add anything in the construction of the
+form of this idea? and still less settle the question whether there is
+any real unity answering to the idea.
+
+If this is a correct distinction, if psychology, as science, does not
+determine questions of validity or objective meaning but only of
+genesis, if it looks at mental states in relation only to their temporal
+and causal concomitants and not to their objects, it must follow that
+our preceding analysis of illusion involves no particular philosophic
+theory as to the nature of intelligence, but, so far as accurate,
+consists of scientific facts which all philosophic theories of
+intelligence must alike be prepared to accept. And I have little doubt
+that each of the two great opposed doctrines, the intuitive and the
+associational, would claim to be in a position to take up these facts
+into its particular theory, and to view them in its own way.
+
+But in addition to this scientific psychology, there is another
+so-called psychology, which is, strictly speaking, philosophic. This, I
+need hardly say, is the association philosophy. It proceeds by analyzing
+certain cognitions and sentiments into their elements, and straightway
+declaring that they mean nothing more than these. That is to say, the
+associationist passes from genesis to validity, from the history of a
+conscious state to its objective meaning. Thus, from showing that an
+intuitive belief, say that in causation, is not original (in the
+individual or at least in the race), it goes on to assert that it is not
+a valid immediate cognition at all. Now, I am not concerned here to
+inquire into the logical value of this transition, but simply to point
+out that it is extra-scientific and distinctly philosophic. If logically
+justifiable, it is so because of some plainly _philosophic_ assumption,
+as that made by Hume, namely, that all ideas not derived from
+impressions are to this extent fictitious or illusory.
+
+And now we are in a position to understand the bearing of our scientific
+analysis of acknowledged illusions on the associationist's treatment of
+the alleged illusions of common sense. There is no doubt, I think, that
+some of the so-called intuitions of common sense have points of analogy
+to acknowledged illusions. For example, the conviction in the act of
+perception that something external to the mind and independent of it
+exists, has a certain superficial resemblance to an hallucination of
+sense; and moreover, the associationist seeks to explain it by means of
+these very processes which underlie what is recognized by all as
+sense-illusion.[158] Again, it may be said that our notions of force and
+of a causal nexus in the physical world imply the idea of conscious
+energy as known through our muscular sensations, and so have a
+suspicious resemblance to those anthropomorphic illusions of which I
+have spoken under Illusions of Insight. Once more, the consciousness of
+freedom may, as I have suggested, be viewed as analogous in its form and
+its mode of origin to illusions of introspection. As a last example, it
+may be said that the mind's certain conviction of the innateness of some
+of its ideas resembles those illusions of memory which arise through an
+inability to think ourselves back into a remote past having a type of
+consciousness widely unlike that of the present.
+
+But now, mark the difference. In our scientific analysis of popularly
+known illusions, we had something by which to determine the illusory
+character of the presentation or belief. We had a popularly or
+scientifically accepted standard of certainty, by a reference to which
+we might test the particular _soi-disant_ cognition. But in the case of
+these fundamental beliefs we have no such criterion, except we adopt
+some particular philosophic theory, say that of the associationist
+himself. Hence this similarity in structure and origin cannot in itself
+be said to amount to a proof of equality of logical or objective value.
+Here again it must be remarked that origin, does not carry validity or
+invalidity with it.[159]
+
+We thus come back to our starting-point. While there are close
+relations, psychological and logical, between the scientific study of
+the ascertained facts of illusion and the philosophic determination of
+what is illusory in knowledge as a whole, the two domains must be
+clearly distinguished. On purely scientific ground we cannot answer the
+question, "How far does illusion extend?" The solution of this question
+must be handed over to the philosopher, as one aspect of his problem of
+cognition.
+
+One or two remarks may, perhaps, be hazarded in concluding this account
+of the relation of the scientific to the philosophic problem of
+illusion. Science, as we have seen, takes its stand on a stable
+consensus, a body of commonly accepted belief. And this being so, it
+would seem to follow, that so far as she is allowed to interest herself
+in philosophic questions, she will naturally be disposed to ask, What
+beliefs are shared in by all minds, so far as normal and developed? In
+other words, she will be inclined to look at universality as the main
+thing to be determined in the region of philosophic inquiry. The
+metaphysical sceptic, fond of daring exploits, may break up as many
+accepted ideas as he likes into illusory _débris_, provided only he has
+some bit of reality left to take his stand on. Meanwhile, the scientific
+mind, here agreeing with the practical mind, will ask, "Will the beliefs
+thus said to be capable of being shown to be illusory ever cease to
+exercise their hold on men's minds, including that of the iconoclast
+himself? Is the mode of demonstration of such a kind as to be likely
+ever to materially weaken the common-sense 'intuition'?"
+
+This question would seem to be most directly answerable by an appeal to
+individual testimony. Viewed in this light, it is a question for the
+present, for some few already allege that in their case philosophic
+reasonings exercise an appreciable effect on these beliefs. And so far
+as this is so, the man of scientific temper will feel that there is a
+question for him.
+
+It is evident, however, that the question of the persistence of these
+fundamental beliefs is much more one for the future than for the
+present. The correction of a clearly detected illusion is, as I have
+more than once remarked, a slow process. An illusion such as the
+apparent movement of the sun will persist as a partially developed error
+long after it has been convicted. And it may be that the fundamental
+beliefs here referred to, even if presumably illusory, are destined to
+exercise their spell for long ages yet.
+
+Whether this will be the case or not, whether these intuitive beliefs
+are destined slowly to decay and be dissolved as time rolls on, or
+whether they will retain an eternal youth, is a question which we of
+to-day seem, on a first view of the matter, to have no way of answering
+which does not assume the very point in question--the truth or falsity
+of the belief. This much may, however, be said. The associationist who
+resolves these erroneous intuitions into the play of association, admits
+that the forces at work generating and consolidating the illusory belief
+are constant and permanent forces, and such as are not likely to be less
+effective in the future than they have been in the past. Thus, he
+teaches that the intuition of the single object in the act of perception
+owes its strength to "inseparable association," according to which law
+the ideas of the separate "possibilities of sensation," which are all we
+know of the object, coalesce in the shape of an idea of a single uniting
+substance. He adds, perhaps, that heredity has tended, and will still
+tend, to fix the habit of thus transforming an actual multiplicity into
+an imaginary unity. And in thus arguing, he is allowing that the
+illusion is one which, to say the least of it, it will always be
+exceedingly difficult for reason to dislodge.
+
+In view of this uncertainty, and of the possibility, if not the
+probability, of these beliefs remaining as they have remained, at least
+approximately universal, the man of science will probably be disposed to
+hold himself indifferently to the question. He will be inclined to say,
+"What does it matter whether you call such an apparently permanent
+belief the correlative of a reality or an illusion? Does it make any
+practical difference whether a universal 'intuition,' of which we cannot
+rid ourselves, be described as a uniformly recurring fiction of the
+imagination, or an integral constitutive factor of intelligence? And, in
+considering the historical aspect of the question, does it not come to
+much the same thing whether such permanent mental products be spoken of
+as the attenuated forms or ghostly survivals of more substantial
+primitive illusions (for example, anthropomorphic representations of
+material objects, 'animistic' representations of mind and personality),
+or as the slowly perfected results of intellectual evolution?"
+
+This attitude of the scientific mind towards philosophic problems will
+be confirmed when it is seen that those who seek to resolve stable
+common convictions into illusions are forced, by their very mode of
+demonstration, to allow these intuitions a measure of validity. Thus,
+the ideas of the unity and externality attributed to the object in the
+act of perception are said by the associationist to answer to a matter
+of fact, namely, the permanent coexistence of certain possibilities of
+sensation, and the dependence of the single sensations of the individual
+on the presence of the most permanent of these possibilities, namely,
+those of the active or muscular and passive sensations of touch, which
+are, moreover, by far the most constant for all minds. Similarly, the
+idea of a necessary connection between cause and effect, even if
+illusory in so far as it expresses an _objective_ necessity, is allowed
+to be true as an expression of that uniformity of our experience which
+all scientific progress tends to illustrate more and more distinctly.
+And even the idea of a permanent self, as distinct from particular
+fugitive feelings, is admitted by the associationist to be correct in so
+far as it expresses the fact that mind is "a series of feelings which
+is aware of itself as past and future." In short, these "illusory
+intuitions," by the showing of those who affirm them to be illusory, are
+by no means hallucinations having no real object as their correlative,
+but merely illusions in the narrow sense, and illusions, moreover, in
+which the ratio of truth to error seems to be a large one.
+
+It would thus appear that philosophy tends, after all, to unsettle what
+appear to be permanent convictions of the common mind and the
+presuppositions of science much less than is sometimes imagined. Our
+intuitions of external realities, our indestructible belief in the
+uniformity of nature, in the nexus of cause and effect, and so on, are,
+by the admission of all philosophers, at least partially and
+_relatively_ true; that is to say, true in relation to certain features
+of our common experience. At the worst, they can only be called illusory
+as slightly misrepresenting the exact results of this experience. And
+even so, the misrepresentation must, by the very nature of the case, be
+practically insignificant. And so in full view of the subtleties of
+philosophic speculation, the man of science may still feel justified in
+regarding his standard of truth, a stable consensus of belief, as above
+suspicion.
+
+
++----------------------------------------------------------------------+
+|Transcribers note: In the original some footnotes read 'note[1]'and    |
+|'note[2]'. They have been renumbered to allow readers to refer directly|
+|to the correct footnote.                                               |
++----------------------------------------------------------------------+
+
+
+INDEX.
+
+
+  A.
+
+  Abercrombie, Dr. J, 141, note[82], 278.
+
+  Abnormal life, relation of,
+    to normal, 1, 120, 121, 124, 182, 277, 284, note[132], 336;
+    effects of amputation, 62;
+    modification of sensibility in, 65;
+    gross sense-illusions of, 111, hallucinations of, 118;
+    sense of personal identity in, 289.
+
+  Active, stage in perception, 27;
+    illusion distinguished from passive, 45, 332-334.
+
+  Actor. _See_ Theatre.
+
+  Adaptation, illusion as want of, 124, 188, 339.
+
+  Æsthetic intuition, 213;
+    illusions of, 214.
+
+  After-dreams, 144, 183.
+
+  After-sensation, after-impression, 55, 115.
+
+  Anæsthesia, 65.
+
+  Ancestral experience, results of, 281.
+
+  Animals, recognition of portraits by, 105;
+    expectation of, 298.
+
+  Anthropomorphism, 225, 360.
+
+  Anticipation. _See_ Expectation.
+
+  Apparitions. _See_ Hallucination.
+
+  Aristotle, 130.
+
+  Art, illusions of, 77, 104.
+
+  Artemidoros, 129.
+
+  Association, laws of, in perception, 22;
+    in dreams, 153, 156;
+    link of resemblance in dreams, 159;
+    associative dispositions in dreams, 169;
+    effect of, in insight, 221;
+    inseparable, 359.
+
+  Associationist, views of, 349, 352, 355.
+
+  Attention, involved in perception 21;
+    absence of, in sense-illusion, 39, 87;
+    relation of, to recognition of objects, 90;
+    expectant, 93;
+    attitude of, in dreaming, 137, 172;
+    to internal mental states, 194;
+    absence of, in errors of insight, 228.
+
+  Authority, influence of, in introspection, 210;
+    in belief, 325.
+
+  Autobiography, errors connected with, 276, 280.
+
+  Automatic activity of centres, in hallucinations, 113;
+    in dreams, 136, 151;
+    automatic intellectual processes, 300, 335, 352.
+
+
+  B.
+
+  Baillarger, J., 13, note[1], 113, note[57], 119,
+    notes[64] and [65], 120, note[66].
+
+  Bain, Dr. A., 32, note[12], 117, note[60], 190.
+
+  Beattie, J., 141, note[82].
+
+  Beauty, sentiment of, 206, 213.
+
+  Belief, immediate, 14, 15, 294;
+    simple and compound, 296;
+    illusory forms of, 297;
+    simple expectation, 297;
+    expectation, of extra-personal experiences, 307;
+    retrospective, 309;
+    in persistent objects and persons, 312;
+    self-esteem, 315;
+    representation of classes of things, 322;
+    representations of mankind, 322;
+    representation of life and the world as a whole, 322;
+    as predisposition to error, 324;
+    amount of divergence in, 325;
+    tendency towards convergence in, 326.
+
+  Beneficial, correct knowledge as, 340;
+    illusion as, 342.
+
+  Berkeley, Bishop, 218, 349, note[154].
+
+  Binet, A., 53, note[20].
+
+  Boismont, Brierre de, 11, note[1].
+
+  Börner, J., 146.
+
+  Braid, James, 186, 187.
+
+  Brewster, Sir D., 42, 73, 81, 116.
+
+  Brücke, E., 77, note[38].
+
+  Byron, Lord, 116.
+
+
+  C.
+
+  Carpenter, Dr. W.B., 32, note[12], 108, 110, note[56], 186, 231,
+    note[111], 265, note[125], 276.
+
+  Castle-building, as illusory perception, 3, 99.
+
+  Cause, idea of, in science, 344;
+    reality of relation of, 347, 349, 356, 360.
+
+  Change, a condition of conscious life, 252, 287, note[133].
+
+  Childhood, our recollections of, 263, 269.
+
+  Children, curiosity of, 175, 180;
+    estimate of time by, 256;
+    confusion of dream and waking life by, 276;
+    imagination of, 279;
+    self-assertion of, 319;
+    intellectual condition of, 357, note[159].
+
+  Clarke, Dr. E.H., 117.
+
+  Classification, in recognition of sensation, 21;
+    in recognition, of object, 24;
+    in introspective recognition, 193.
+
+  Clifford, Professor W.K., 56, note[24].
+
+  Coalescence, of sensations, 43, 52;
+    of dream-images, 162;
+    of internal feelings, 196;
+    of mnemonic images, 265.
+
+  Coenæsthesis, 41, 99, 145, 286, 288.
+
+  Cognition, immediate or intuitive, 5, 14-16, 294;
+    presentative and representative, 9, 13, 217, 330;
+    nature of, in dreams, 168, 172;
+    nature of, generally, 295, 331;
+    philosophic problems of, 346.
+
+  Colour, external reality of, 8, 37;
+    illusory perception of, 37, 88;
+    subjective complementary colours (colour-contrast), 67, 83.
+
+  Coloured media, objects seen through, 82.
+
+  Common cognition, and truth, 337;
+    genesis and validity of, 353.
+
+  Common experience distinguished from
+    individual, 26, 27, 137, 209, 214, 336, 351;
+    illusion as, 47,325, 337.
+
+  Common sense, intuitions of, 346, 349, 352, 357.
+
+  Complementary colours, 67, 83.
+
+  Concave, apparent conversion of, into convex, 84.
+
+  Conjuror, tricks of, 56, 106.
+
+  Consciousness, veracity of, 192, 205;
+    inspection of phenomena of, 196;
+    of self, 283, 285.
+
+  Consensus, the standard of truth, 7, 8, 211, 325, 338, 357.
+
+  Conservation of energy, 343.
+
+  Construction, rational, in dreams, 170.
+
+  Continuum, the perception of the world as, 52, 56, note[24].
+
+  Correction of illusion, in sense-illusion, 38, 124, 137;
+    dreams, 182;
+    introspection, 210;
+    insight, 229;
+    memory, 291;
+    historical correction 338;
+    intellectual processes involved in, 351.
+
+  Criterion of illusion, 337.
+
+  Cudworth, R., 161
+
+
+  D.
+
+  Deception of the senses, 19;
+    self-deception, 200;
+    conscious deception of others, 222.
+
+  Delboeuf, J., 175, note[97], 235, note[113].
+
+  _Delirium tremens_, 118, note[62].
+
+  Democritus, 130.
+
+  De Quincey, 253, 280.
+
+  Descartes, R., 116, 350.
+
+  Dickens, Charles, 277.
+
+  Direction, illusory sense of, in vision, 66, 71, 73;
+   in hearing, 72, 75.
+
+  Disease. _See_ Abnormal life.
+
+  Dissolution. _See_ Evolution.
+
+  Doubt, starting-point in philosophy, 350.
+
+  Dreams, relation of, to illusions of sense, 18, 130;
+    and waking experience, 127;
+    theories of, 128;
+    physiology of, 131;
+    extent of, in sleep, 132;
+    psychological conditions of, 136;
+    excitants of, 139, 143;
+    exaggeration in, 147;
+    symbolism of, 149;
+    as results of automatic activity of centres, 151;
+    as results of association, 153;
+    structure of, 156;
+    incoherent, 156;
+    coherent, 161;
+    action of feeling in, 164;
+    play of associative dispositions in, 168;
+    co-operation of attention and intelligence in, 172;
+    limits of intelligence in, 180;
+    after-dreams, 183, 274;
+    relation of, to hypnotic condition, 185;
+    experience of, in relation to errors of memory, 273.
+
+
+  E.
+
+  Eccentricity, law of, 59.
+
+  Ego. _See_ Self.
+
+  Emotion, and illusion of perception, 103;
+    and hallucination, 115;
+    and bodily sensations, 150;
+    control of dreams by, 164;
+    introspection of, 199;
+    and illusion of introspection, 203;
+    and æsthetic intuition, 213;
+    and illusion of memory, 270;
+    and illusion of belief, 306, 324;
+    and cognition generally, 357, note[159].
+
+  Empiricism, philosophic, 348.
+
+  _Ennui_, and sense of time, 250.
+
+  Environment, sources of sense-illusion in, 47, 48, 70;
+    view of, in mental disease, 290, 326;
+    view of, in normal life, 323;
+    action of, in assimilating belief, 339.
+
+  Error, immediate and mediate, 6, 334.
+
+  Esquirol, J.E.D., 12, note[2].
+
+  Evolution, relation of, to dissolution, 122;
+    of power of introspection, 209;
+    of power of insight, 230;
+    and self-assertion, 320;
+    evolutionist's view of error, 339;
+    doctrine of, as science, 346.
+
+  Exaggeration, in interpretation of sensations, 65;
+    in dream-interpretation, 147;
+    in memory, 269.
+
+  Expectation, preliminary to perception, 30;
+    and illusory perception, 93, 102, 106;
+    nature of, 295;
+    and memory, 298;
+    of new experience, 301;
+    of remote events, 302;
+    measurement of duration in, 302;
+    action of imagination in, 305;
+    extension of meaning of, 307, 308.
+
+  Experience, effect of, in perception, 22, 68, 85, 86, 91;
+    external and internal, 194, 210;
+    revivals of waking, in dreams, 152;
+    effects of present, on retrospection, 267;
+    anticipation of new, 301.
+
+  External world. _See_ World.
+
+
+  F.
+
+  Fallacy and illusion 6, 335;
+    of testimony, 265.
+
+  Familiarity, sense of, in new objects, 272, 281.
+
+  Fechner, G.T., 51.
+
+  Ferrier, Dr., 32, note[12], 58, note[26].
+
+  Fiction, as producing illusion, 278, 279, 311.
+
+  Fitness. _See_ Adaptation.
+
+  Flattery, _rationale_ of, 200, 222.
+
+  Forgetfulness and illusion, 278, 279, 311.
+
+  Free-will, doctrine of, 207, 342, 356.
+
+  Future. _See_ Expectation.
+
+
+  G.
+
+  Galton, F., 117.
+
+  Ghosts. _See_ Hallucination.
+
+  Goethe, 116, 117, 280 and note[131].
+
+  Griesinger, W., 13, note[2], 63, note[31], 66, note[32], 115, 118,
+    note[62], 119, note[64], 120, note[66], 290, note[135], 327,
+    note[146].
+
+  Gruithuisen, 143, 144.
+
+  Gurney, E., 224, note[109].
+
+
+  H.
+
+  Hall, G.S., 186, note[102].
+
+  Hallucination, and illusion, 11, 109, 111, 112, 121;
+    and subjective sensation, 63, 109, 121;
+    sensory and motor, 66;
+    nervous conditions of, 112-114;
+    incomplete and complete, 113;
+    as having either central or peripheral origin, 113;
+    causes of, classified, 115;
+    in sane condition, 116;
+    in insanity, 118;
+    visual and auditory, 119;
+    dreams regarded as, 139, 151;
+    hypnagogic, 143;
+    after-dreams and ghosts, 183;
+    of memory, 271;
+    relation of, to errors of belief, 322;
+    intuition of external world regarded as, 355.
+
+  Happiness, feeling of, 200.
+
+  Harmful, illusion as, 188, 229, 292, 339.
+
+  Harmless, illusions as, 124, 292, 341.
+
+  Hartley, D., 139, 256, note[124], 279.
+
+  Hearing, as mode of perception, 34, 48;
+    localization of impression in, 60;
+    sense of direction in, 72;
+    activity of, in sleep, 140;
+    and muscular sense, 171.
+
+  Heidenhain, Dr., 186-188.
+
+  Helmholtz, H., 22, 23, note[7], 44, 51, 54 and note[22], 55, note[23],
+    57, 67, note[33], 78, note[39], 80, 85, note[43], 88, 90, 207,
+    note[105].
+
+  Heraclitus, 137.
+
+  Heredity, and illusion of memory, 280;
+    action of, in perpetuating intuition, 359.
+
+  Hering, E., 67, note[33].
+
+  Hodgson, Shadworth H., 347, note[153].
+
+  Holland, Sir H., 277.
+
+  Hood, Thomas, 146.
+
+  Hope, illusory. _See_ Expectation.
+
+  Hoppe, Dr. J.I., 51, 58, note[26].
+
+  Horwicz, A., 145, note[85].
+
+  Hume, D., 355.
+
+  Huxley, Professor T., 119, note[1].
+
+  Hyperæsthesia, 65.
+
+  Hypnotism, 185.
+
+  Hypochondria, 65.
+
+  Hypothesis, as illusory, 310, 311.
+
+
+  I.
+
+  Idealism, 348.
+
+  Identity, cases of mistaken, 267.
+
+  Identity, personal, confusion of, in dreams, 163;
+    consciousness of, 241, 267, 282, 285;
+    illusory forms of, 283;
+    gross disturbances of, in normal life, 287;
+    in abnormal life, 289;
+    momentary confusions of, 293.
+
+  Illusion, definition of, 1;
+    varieties of, 9;
+    extent of, 328;
+    _rationale_ of, 331, 337.
+
+  Image (physical). _See_ Reflection.
+
+  Image (mental), in perception, 22;
+    seat of, 32;
+    in dreams, 138;
+    mnemonic, 236.
+
+  Imagination, play of, in perception, 95, 99;
+    and sense-illusion, 106;
+    nature of, in dreaming, 136, 161;
+    as antecedent of dream, 152, 158;
+    as poetic interpretation of nature, 224;
+    memory corrupted by effect of past, 264, 273, 277;
+    present, creating the semblance of recollection, 267, 271;
+    play of, in expectation, 305;
+    as element of illusion generally, 333.
+
+  Immediate. _See_ Cognition.
+
+  Individual, and common experience, 26, 27, 137, 209, 214, 336;
+    dream-experience as, 44, 68;
+    internal experience as, 209;
+    memory as, 232;
+    belief and truth, 338.
+
+  Inference, and immediate knowledge, 6, 334;
+    in perception, 22, 26, 68;
+    in belief, 295.
+
+  Innate, recollection as, 280;
+    principles, 295, 356.
+
+  Insane, sense-illusions of, 63, 65, 111;
+    hallucinations of, 118;
+    dreaming and state of, 182;
+    mnemonic illusions of, 278, 289;
+    beliefs of, 327.
+
+  Insight, nature of, 217;
+    illusions of, defined, 220;
+    passive illusions of, 220;
+    histrionic illusion, 222;
+    active illusions of, 223;
+    poetic interpretation of nature, 224;
+    value of faculty of, 228.
+
+  Interpretation, in correct perception, 22;
+    of impression and experience, 70;
+    and volition, 95;
+    and fixed habits of mind, 101;
+    and temporary attitude of mind, 102;
+    of sensations in dreams, 137, 147;
+    of internal feelings, 203;
+    of others' feelings, 217;
+    of nature by poet, 225;
+    recollection as, 242.
+
+  Introspection, nature of, 14, 189;
+    illusory forms of, 190;
+    confusion of inner and outer experiences, 194;
+    inaccurate inspection of feelings, 196;
+    presentation and representation confused, 199;
+    feelings and inferences from these, 203;
+    moral self-scrutiny, 204;
+    philosophic, 205;
+    value of, 208.
+
+  Intuition. _See_ Cognition.
+
+  Intuitivism, 348.
+
+
+  J.
+
+  Jackson, Dr. J. Hughlings, 27, note[9], 33, 123, note[67].
+
+  Johnson, Dr., 116.
+
+
+  K.
+
+  _Klang_, as compound sensation, 53.
+
+  Knowledge. _See_ Cognition.
+
+
+  L.
+
+  Language, function of, 195.
+
+  Leibnitz, 133.
+
+  Lélut, L.F., 120, note[66].
+
+  Lessing, G. E., 133, note[73].
+
+  Leuret, 290, note[135].
+
+  Lewes, G.H., 28, 32, note[12], 52, note[30], 62, note[1], 68,
+    note[35], 89, note[45], 115, note[58], 150.
+
+  Life, our estimate of, 323, 326, 327.
+
+  Light, sensation and perception of, 59;
+    effects of reflection and refraction, of, 73;
+    representation, of, in painting, 88, 91;
+    action of, in sleep, 140.
+
+  Localization, as local discrimination of sensations, 52;
+    as localizing of sensations, 59, 60;
+    illusory, 61, 82;
+    in hallucination, 118, 119;
+    in dreaming, 148;
+    of events in time, in memory, 238, 245;
+    in expectation, 304.
+
+  Locke, 133, note[73].
+
+  Lotze, H., 60, note[29].
+
+  Lover, illusion of, 224, 227, 342.
+
+  Luminosity of painting, 88, 91.
+
+  Lustre, as compound sensation, 54.
+
+  Lyell, Sir Charles, 311.
+
+
+  M.
+
+  Magic, arts of, 73.
+
+  Magnitude, apparent, in vision, 75, note[37];
+    perception of, in pictorial art, 88, 91;
+    of time-intervals, 245, 249;
+    recollection of, 268.
+
+  Malebranche, 116.
+
+  Mankind, our views of, 322.
+
+  Matter. _See_ World (material).
+
+  Maudsley, Dr. H., 32, note[12].
+
+  Maury, A., 140, 143, 153, note[92], 159, 163, note[94], 173.
+
+  Mayer, Dr. A., 66, note[32].
+
+  Measurement, subjective, of time, 245.
+
+  Media, coloured, illusions connected with presence of, 82.
+
+  Memory, nature of, 9, 13, 231;
+    veracity of, 232, 290;
+    defined, 234;
+    psychology of, 236;
+    physiology of, 237;
+    localization of events in, 238;
+    and sense of personal identity, 241, 283;
+    illusions of, 241;
+    illusory localization, 245, 256;
+    distortions of, 261;
+    hallucinations of, 271;
+    illusions respecting personal identity, 283;
+    relation of, to belief, 295;
+    compared with expectation, 297;
+    and inference, 335.
+
+  Metempsychosis, 294.
+
+  Meyer, H., 83, 144.
+
+  Mill, J.S., 298, note[138], 309.
+
+  Mirrors, as means of delusion, 73.
+
+  Misanthropist, 2, 323.
+
+  Mitchell, Dr. Weir, 62.
+
+  Monomania, 111.
+
+  Moral, intuition, 216;
+    self-inspection, 204.
+
+  Motor illusions. _See_ Muscular sense.
+
+  Movement, apparent, 50, 57, 73, 81, 95, 107;
+    in dreams, 142, 154.
+
+  Müller, Johannes, 58, note[27], 100, 117, 143.
+
+  _Muscæ volitantes_, 118, note[62].
+
+  Muscular sense, in perception, 23;
+    illusions connected with, 50, 57, 62, 66;
+    co-operation, of, in dreams, 142, 154.
+
+  Music, subjective interpretation of, 223.
+
+
+  N.
+
+  Natural selection, effect of, in eliminating error, 340.
+
+  Nature, personification of, 224;
+    uniformity of, 344, 360.
+
+  Necessity, idea of, 349, 360.
+
+  Nervous system, and conditions of perception, 31;
+    connections of, 32, 169;
+    function of, and force of stimulus, 47, 50;
+    prolonged activity of, 55;
+    specific energy of, 58;
+    variations in state of, 64;
+    fatigue of, 65, 115;
+    disease of, _ibid._;
+    nervous conditions of hallucination, 112, 115;
+    nervous dissolution and evolution, 122;
+    condition of, in sleep, 131;
+    in hypnotic condition, 186;
+    nervous conditions of memory, 237;
+    nervous conditions of illusion in general, 334.
+
+  Normal life, relation of,
+    to abnormal, 1, 121, 124, 182, 277, 284, note[132];
+    hallucinations of, 116.
+
+
+  O.
+
+  Object, nature of, 36, 353.
+
+  Objective and subjective experience, 26, 27, 137, 214.
+
+  Old age, dreams how regarded in, 276.
+
+  Oneirocritics, 129.
+
+  Opera, illusion connected with, 104.
+
+  Optimism, 323, 327, 342.
+
+  Organic sensations, discrimination of, 41;
+    interpretation of, 99;
+    in sleep, 145, 148.
+
+  Organism, conditions of illusion in, 47, 50;
+    relation of our conception of the universe to sensibilities of, 343.
+
+  Orientation, 125, 138.
+
+
+  P.
+
+  Pain, recollection of, 264, 270.
+
+  Painting, representation of third dimension by, 77;
+    apparent movement of eye in portrait, 81;
+    discrepancies between, and object in magnitude and luminosity, 88;
+    realization of, and mental preparation, 105;
+    realization of, by animals, 105.
+
+  Paræsthesia, 68.
+
+  Paralysis of ocular muscles, 66.
+
+  Passive, and active factor in perception, 27;
+    and active illusion, 45.
+
+  Percept, 22;
+    and sense-impression, 59.
+
+  Perception, a form of immediate knowledge, 10, 13, 17, 18;
+    external and internal, 14;
+    philosophy of, 14, 20, 22, 36, 346, 348, 353, 355, 359;
+    illusions of, 19, 35;
+    psychology of, 20;
+    and inference, 22, 26, 76;
+    physiological conditions of, 31.
+
+  Persistent objects, representation of, 312.
+
+  Persistent self. _See_ Personal identity.
+
+  Personal equation, in perception, 101;
+    in æsthetic intuition, 214;
+    in memory, 292;
+    in belief, 324.
+
+  Personal identity, consciousness of, 241, 282, 285;
+    illusions connected with, 283;
+    disturbances in sense of, 287;
+    sense of, in insanity, 289;
+    momentary confusions of, 293;
+    philosophic problem of, 285, 354, 360.
+
+  Personification of nature, 224.
+
+  Perspective, linear, 79, 97, 98;
+    aerial, 80;
+    of memory, 245.
+
+  Pessimism, 323, 327.
+
+  Phenomenalism, 348.
+
+  Philosophy, conception of illusion by, 7, 36, 205, 285, 349;
+    of mind, 132, 285, 344, 348;
+    as theory of knowledge, 295, 346;
+    and science, 346, 348;
+    and common sense, 347, 349;
+    problems of, 347.
+
+  Phosphenes, 58.
+
+  Physical science. _See_ Science.
+
+  Plato, 281.
+
+  Platonists, 349.
+
+  Pleasure, feeling of, 200;
+    recollection of, 264, 270.
+
+  Plutarch, 133, note[73].
+
+  Poetry, lyrical and dreams, 164;
+    misinterpretation of, 223;
+    personification, 224.
+
+  Points, discrimination of, 52.
+
+  Poisons, action of, 115.
+
+  Pollock, F., 184, note[101].
+
+  Pollock, W.H., 184.
+
+  Predisposition, action of, in perception, 44, 101, 102;
+    in æsthetic intuition, 215;
+    in insight, 223;
+    in recollection, 268;
+    in belief, 305, 319;
+    belief as, 324.
+
+  Prejudice. _See_ Predisposition.
+
+  Prenatal experience, recollection of, 281.
+
+  Preperception, 27;
+    illusions connected with, 44, 93;
+    voluntary, 95;
+    result of habit of mind, 101;
+    result of temporary conditions, 102;
+    as sub-expectation, 102;
+    as definite expectation, 106.
+
+  Presentation and representation, 9, 10, 13, 14, 192, 234, 329, 330.
+
+  Projection, outward, of sensations, 63;
+    of mental image, 111, 112;
+    of solid form on flat, 79, 81, 96.
+
+  Prophetic, dreams as, 129, 147, note[88];
+    enthusiast, 307.
+
+  Psychology, popular and scientific, 9, 10;
+    distinguished from philosophy, 14, 36, 345, 352;
+    introspective method of, 208;
+    as a kind of philosophy, 305.
+
+  Public events, localization, of, by memory, 258.
+
+
+  R.
+
+  Radestock, P., 130, note[71], 132, note[72], 134, note[75], 140, 141,
+    149, note[90], 162, 182, 275.
+
+  Rationalism, philosophic, 348.
+
+  Realism, 348.
+
+  Reality, nature of, 36, 346.
+
+  Recognition, and perception, 24, 25;
+    illusions of, 87;
+    and memory, 234.
+
+  Reflection (of light), illusions connected with, 73, 83.
+
+  Refraction and optical illusion, 73.
+
+  Relative, sensation as, 64;
+    attention to magnitude and brightness as, 91;
+    estimate of duration as, 249.
+
+  Relief, illusory perception of, 75, 96.
+
+  Representation and presentation, 9, 10, 13, 14, 192.
+
+  Retrospection. _See_ Memory.
+
+  Ribot, T., 238, note[114], 290, note[135].
+
+  Richter, J.P., 143.
+
+  Robertson, Professor G.C., 35, note[14].
+
+  Romanes, G.J., 105, note[2], 250, note[122].
+
+  Rousseau, 280.
+
+
+  S.
+
+  Savage, dream theory of, 128;
+    idea of nature of, 225.
+
+  Scherner, C.A., 140, 149.
+
+  Schopenhauer, A., 145, 342.
+
+  Schroeder, H., 85.
+
+  Science, philosophy and, 8, 36, 285, 344;
+    conception of the material world in physical, 36, 343, 346, 347;
+    and common cognition, 338, 357.
+
+  Scott, Sir W., 116, 125.
+
+  Secondary qualities, 36, 344.
+
+  Selection, process of, in perception, 95;
+    in dreams, 174;
+    in memory, 257, 263.
+
+  Self, confusion of, in dreams, 163;
+    introspective knowledge of, 192;
+    self-deception, 200;
+    identity of, 241, 282, 285;
+    confusion of present and past, 267, 284;
+    disturbances in recognition of, 287, 289;
+    momentary confusions of, 295;
+    confusion of present and future, 305.
+
+  Self-esteem, illusion of, 315;
+    origin of, 319;
+    utility of, 342.
+
+  Self-preservation, 320.
+
+  Sensation, element in perception, 20;
+    discrimination and classification of, 21;
+    interpretation of, 22;
+    inattention to, 39, 87;
+    modified by central reaction, 39, 87, 89, 91;
+    confusion of novel, 40;
+    indistinct, 41;
+    misinterpretation of, 44;
+    relation of, to stimulus, 46, 50;
+    limits to discrimination of, 52;
+    after-impression, 55;
+    subjective, 59, 62, 107, 143;
+    localization of, 59.
+
+  Sensibility, limits of, 50;
+    variations of, 64.
+
+  Sensualism, philosophic, 348.
+
+  Shadow, cast, 77.
+
+  Shakespeare, 3.
+
+  Sight, mode of perception, 19, 33, 34, 48, 49;
+    local discrimination in, 52;
+    single vision, 54;
+    localization of impression in, 60;
+    in sleep, 139;
+    images of, in sleep, 150, 154.
+
+  Single, vision, 54;
+    touch, 72.
+
+  Sleep, mystery of, 127;
+    physiology of, 131.
+
+  Sleight of hand. _See_ Conjuror.
+
+  Smell, as mode of perception, 34, note[14];
+    localization of impression in, 60;
+    subjective sensations of, 108;
+    in sleep, 141;
+    and taste, 171.
+
+  Solidity, illusory perception of, 75, 96.
+
+  Space, representation of, 207.
+
+  Specific energy of nerves, 58.
+
+  Spectra, ocular, etc. _See_ Subjective sensation.
+
+  Spencer, Herbert, 32, note[12], 128, note[69], 323, 340.
+
+  Spinoza, 143, 184.
+
+  Spiritualist _séances_, 103, 107, 123, 265.
+
+  Stereoscope, 75.
+
+  Stewart, Dugald, 172, 306.
+
+  Stimulus, qualitative relation of, to sensations, 46, 58, 67;
+    quantitative relation of, to sensation, 50, 64;
+    after-effect of, 55;
+    prolonged action of, 56;
+    subjective or internal, 62;
+    exceptional relation of, to organ, 70;
+    action of, in sleep, 135, 139, 143;
+    in hypnotic condition, 186.
+
+  Strümpell, L., 144, 147, note[89].
+
+  Subjective, experience, 26, 27, 137, 214;
+    movement, 51, 57;
+    sensation, 59, 62, 107, 113, 121, 143.
+
+  Suggestion, by external circumstances, 30, 44, 89, 91, 267;
+    verbal, 30, 106, 188, 215, 268, 301, 310.
+
+  Symbol, dream as, 129, 149.
+
+  Sympathy, basis of knowledge, 223;
+    and illusion of insight, 223;
+    and illusion of memory, 277;
+    and momentary illusion, 293.
+
+
+  T.
+
+  Taine, H., 60, note[29], 108, note[54], 117, note[59], 137,
+    298, note[137], 356, note[158].
+
+  Taste, æsthetic. _See_ Æsthetic intuition.
+
+  Taste, localization of impression in, 60;
+    subjective sensations of, 63;
+    variations in sensibility, 68;
+    activity of, in sleep, 141;
+    and smell, 171.
+
+  Temperament, a factor in sense-illusion, 101;
+    in dreams, 137;
+    in illusory belief, 325;
+    in illusion generally, 334, note[149].
+
+  Temperature, sense of, 65.
+
+  Tennyson, A., 226.
+
+  Testa, A.J., 131.
+
+  Testimony, of consciousness, 205;
+    fallacies of, 265;
+    to identity, 267.
+
+  Thaumatrope, 56.
+
+  Theatre, illusion of the, 104, 222;
+    self-deception of the actor, 200.
+
+  Thompson, Professor S.P., 51, note[17].
+
+  Thought, in relation to belief, 326.
+
+  Time, retrospective idea of, 239, 246, 250;
+    constant error in estimate of, 245;
+    subjective estimate of, 249;
+    contemporaneous estimate of, 250;
+    sense of, in insanity, 290;
+    prospective estimate of, 303.
+
+  Touch, as form of perception, 33, 34, 49;
+    local discrimination in, 52;
+    subjective sensations of, 62;
+    variations in sensibility of, 65;
+    in sleep, 141.
+
+  Transformation, in perception, 94;
+    of images in dreams, 163;
+    in memory, 262, 267;
+    in expectation, 305.
+
+  Trick. _See_ Conjuror.
+
+  Tuke, Dr., 110.
+
+  Tylor, E.B., 128, note[69].
+
+
+  U.
+
+  Unconscious, inference, 22, 68, 269, 335, note[150];
+    mental activity, 133, 235;
+    impressions, 41, 152.
+
+  Useful. _See_ Beneficial.
+
+
+  V.
+
+  Vanity. _See_ Self-esteem.
+
+  Venn, J., 299, note[139].
+
+  Ventriloquism, 82.
+
+  Verification, of sense-impression, 38, 351;
+    of self-inspection, 210;
+    of memory, 291.
+
+  Verisimilitude, in art, 80, 88;
+    in theatrical representation, 104;
+    in dreams, 168.
+
+  Vierordt, 245.
+
+  Vision. _See_ Sight.
+
+  Visions, 1, 110;
+    dreams regarded as, 128, 131.
+
+  Vital sense. _See_ Coenæsthesis.
+
+  Voice, internal, 119, 194;
+    activity of, in dreams, 155.
+
+  Volition, and perception, 95;
+    absence of, during sleep, 137,172;
+    co-operation of, in correction, of illusion, 352.
+
+  Volkelt, J., 172.
+
+
+  W.
+
+  Weber, E.H., 43.
+
+  Weinhold, Professor, 186.
+
+  Wetness, perception of, 53.
+
+  Wheatstone, Sir C, 75.
+
+  Wheel of life, 56.
+
+  Will. _See_ Volition.
+
+  Wordsworth, W., 281.
+
+  World, our estimate of, 323, 326, 327;
+    scientific conception of material, 8, 36, 343, 344;
+    reality of external, 344-346, 349, 353, 355, 360.
+
+  Wundt, Professor, W. 13, note[2], 31, note[11], 32, note[12], 58,
+    note[27], 67, note[34], 75, 93, note[47], 118, note[63], 136,
+    note[77], 139, 143, 177, 246, 247, note[119], 251, 252, 254.
+
+
+THE END
+
+
+FOOTNOTES:
+
+[1] A history of the distinction is given by Brierre de Boismont, in his
+work _On Illusions_ (translated by R. T. Hulme, 1859). He says that
+Arnold (1806) first defined hallucination, and distinguished it from
+illusion. Esquirol, in his work, _Des Maladies Mentales_ (1838), may be
+said to have fixed the distinction. (See Hunt's translation, 1845, p.
+111.)
+
+[2] This fact has been fully recognized by writers on the pathology of
+the subject; for example, Griesinger, _Mental Pathology and
+Therapeutics_ (London, 1867), p. 84; Baillarger, article, "Des
+Hallucinations," in the _Mémoires de l'Académie Royale de Médecine_,
+tom. xii. p. 273, etc; Wundt, _Physiologische Psychologie_, p. 653.
+
+[3] I here touch on the distinction between the psychological and the
+philosophical view of perception, to be brought out more fully
+by-and-by.
+
+[4] It might even be urged that the order here adopted is scientifically
+the best, since sense-perception is the earliest form of knowledge,
+introspected facts being known only in relation to perceived facts. But
+if the mind's knowledge of its own states is thus later in time, it is
+earlier in the logical order, that is to say, it is the most strictly
+presentative form of knowledge.
+
+[5] Here and elsewhere I use the word "impression" for the whole complex
+of sensation which is present at the moment. It may, perhaps, not be
+unnecessary to add that, in employing this term, I am making no
+assumption about the independent existence of external objects.
+
+[6] Psychological usage has now pretty well substituted the term "image"
+for "idea," in order to indicate an individual (as distinguished from a
+general) representation of a sensation or percept. It might, perhaps, be
+desirable to go further in this process of differentiating language, and
+to distinguish between a sensational image, _e.g._ the representation of
+a colour, and a perceptional image, as the representation of a coloured
+object. It may be well to add that, in speaking of a fusion of an image
+and a sensation, I do not mean that the former exists apart for a single
+instant. The term "fusion" is used figuratively to describe the union of
+the two sides or aspects of a complete percept.
+
+[7] This impulse to fill in visual elements not actually present is
+strikingly illustrated in people's difficulty in recognizing the gap in
+the field of vision answering to the insensitive "blind" spot on the
+retina. (See Helmholtz, _Physiologische Optik_, p. 573, _et seq._)
+
+[8] This relation will be more fully discussed under the head of
+"Memory."
+
+[9] I adopt this distinction from Dr. J. Hughlings Jackson. See his
+articles, "On Affections of Speech from Diseases of the Brain," in
+_Brain_, Nos. iii. and vii. The second stage might conveniently be named
+apperception, but for the special philosophical associations of the
+term: _Problems of Life and Mind_, third series, p. 107. This writer
+employs the word "preperception" to denote this effect of previous
+perception.
+
+[10] Such verbal suggestion, moreover, acting through a
+sense-impression, has something of that vividness of effect which
+belongs to all excitation of mental images by external stimuli.
+
+[11] See Wundt, _Physiologische Psychologie_, p. 723.
+
+[12] For a confirmation of the view adopted in the text, see Professor
+Bain, _The Senses and the Intellect_, Part II. ch. i. sec. 8; Herbert
+Spencer, _Principles of Psychology_, vol. i. p. 234, _et passim_; Dr.
+Ferrier, _The Functions of the Brain_, p. 258, _et seq._; Professor
+Wundt, _op. cit._, pp. 644, 645; G. H. Lowes, _Problems of Life and
+Mind_, vol. v. p. 445, _et seq._ For an opposite view, see Dr.
+Carpenter, _Mental Physiology_, fourth edit., p. 220, etc.; Dr.
+Maudsley, _The Physiology of Mind_, ch. v. p. 259, etc.
+
+[13] See note, p. 22.
+
+[14] Touch gives much by way of interpretation only when an individual
+object, for example a man's hat, is recognized by aid of this sense
+alone, in which case the perception distinctly involves the reproduction
+of a complete visual percept. I may add that the organ of smell comes
+next to that of hearing, with respect both to the range and definiteness
+of its simultaneous sensations, and to the amount of information
+furnished by these. A rough sense of distance as well as of direction is
+clearly obtainable by means of this organ. There seems to me no reason
+why an animal endowed with fine olfactory sensibility, and capable of an
+analytic separation of sense elements, should not gain a rough
+perception of an external order much more complete than our auditory
+perception, which is necessarily so fragmentary. This supposition
+appears, indeed, to be the necessary complement to the idea first
+broached, so far as I am aware, by Professor Croom Robertson, that to
+such animals, visual perception consists in a reference to a system of
+muscular feelings defined and bounded by strong olfactory sensations,
+rather than by tactual sensations as in our case.
+
+[15] It may be said, perhaps, that the exceptional direction of
+attention, by giving an unusual intensity to the impression, causes us
+to exaggerate it just as in the case of a novel sensation. An effort of
+attention directed to any of our vague bodily sensations easily leads us
+to magnify its cause. A similar confusion may arise even in direct
+vision, when the objects are looked at in a dim light, through a want of
+proper accommodation. (See Sir D. Brewster, _op. cit._, letter i)
+
+[16] They might also be distinguished as objective and subjective
+illusions, or as illusions _a posteriori_ and illusions _a priori_.
+
+[17] _Die Schein-Bewegungen_, von Professor Dr. J.I. Hoppe (1879); _cf._
+an ingenious article on "Optical Illusions of Motion," by Professor
+Silvanus P. Thompson, in _Brain_, October, 1880. These illusions
+frequently involve the co-operation of some preconception or
+expectation. For example, the apparent movement of a train when we are
+watching it and expecting it to move, involves both an element of
+sense-impression and of imagination. It is possible that the illusion of
+table-turning rests on the same basis, the table-turner being unaware of
+the fact of exerting a certain amount of muscular force, and vividly
+expecting a movement of the object.
+
+[18] _Physiologische Optik_, p. 316.
+
+[19] It is plain that this supposed error could only be brought under
+our definition of illusion by extending the latter, so as to include
+sense-perceptions which are contradicted by reason employing idealized
+elements of sense-impression, which, as Lewes has shown (_Problems of
+Life and Mind_, i. p. 260), make up the "extra-sensible world" of
+science.
+
+[20] An ingenious writer, M. Binet, has tried to prove that the fusion
+of homogeneous sensations, having little difference of local colour, is
+an illustration of this principle. (See the _Revue Philosophique_,
+September, 1880.)
+
+[21] Even the fusion of elementary sensations of colour, on the
+hypothesis of Young and Helmholtz, in a seemingly simple sensation may
+be explained to some extent by these circumstances, more especially the
+identity of local interpretation.
+
+[22] The perception of lustre as a single quality seems to illustrate a
+like error. There is good reason to suppose that this impression arises
+through, a difference of brightness in the two retinal images due to the
+regularly reflected light. And so when this inequality of retinal
+impression is imitated, as it may easily be by combining a black and a
+white surface in a stereoscope, we imagine that we are looking at one
+lustrous surface. (See Helmholtz, _Physiologische Optik_, p. 782, etc.,
+and _Populäre wissenschaftliche Vorträge_, 2tes Heft, p. 80.)
+
+[23] The conditions of the production of these double images have been
+accurately determined by Helmholtz, who shows that the coalescence of
+impressions takes place whenever the object is so situated in the field
+of vision as to make it practically necessary that it should be
+recognized as one.
+
+[24] These illusions are, of course, due in part to inattention, since
+close critical scrutiny is often sufficient to dispel them. They are
+also largely promoted by a preconception that the event is going to
+happen in a particular way. But of this more further on. I may add that
+the late Professor Clifford has argued ingeniously against the idea of
+the world being a continuum, by extending this idea of the wheel of
+life. (See _Lectures and Essays_, i. p. 112, _et seq._)
+
+[25] It is supposed that in the case of every sense-organ there is
+always some minimum forces of stimulus at work, the effect of which on
+our consciousness is _nil_.
+
+[26] See Helmholtz, _Physiologische Optik_, p. 603. Helmholtz's
+explanation is criticised by Dr. Hoppe, in the work already referred to
+(sec. vii), though I cannot see that his own theory of these movements
+is essentially different. The apparent movement of objects in vertigo,
+or giddiness, is probably due to the loss, through a physical cause, of
+the impressions made by the pressure of the fluid contents of the ear on
+the auditory fibres, by which the sense of equilibrium and of rotation
+is usually received. (See Ferrier, _Functions of the Brain_, pp. 60,
+61.)
+
+[27] I do not need here to go into the question whether, as Johannes
+Müller assumed, this is an original attribute of nerve-structure, or
+whether, as Wundt suggests, it is due simply to the fact that certain
+kinds of nervous fibre have, in the course of evolution, been slowly
+adapted to one kind of stimulus.
+
+[28] I here refer to what is commonly supposed to be the vague innate
+difference of sensation according to the local origin, before this is
+rendered precise, and added to by experience and association.
+
+[29] The illusory character of this simple mode of perception is seen
+best, perhaps, in the curious habit into which we fall of referring a
+sensation of contact or discomfort to the edge of the teeth, the hair,
+and the other insentient structures, and even to anything customarily
+attached to the sentient surface, as dress, a pen, graving tool, etc. On
+these curious illusions, see Lotze, _Mikrokosmus_, third edit., vol. ii.
+p. 202, etc.; Taine, _De l'Intelligence_, tom. ii. p. 83, _et seq._
+
+[30] Quoted by G.H. Lewes, _Problems of Life and Mind_, third series, p.
+335. These illusions are supposed to involve an excitation of the
+nerve-fibres (whether sensory or motor) which run to the muscles and
+yield the so-called muscular sensations.
+
+[31] It is brought out by Griesinger (_loc. cit._) and the other writers
+on the pathology of illusion already quoted, that in the case of
+subjective sensations of touch, taste, and smell, no sharp line can be
+drawn between illusion and hallucination.
+
+[32] For a fuller account of these pathological disturbances of
+sensibility, see Griesinger; also Dr. A. Mayer, _Die Sinnestäuschungen_.
+
+[33] Helmholtz, _op. cit._, p. 600, _et seq._ These facts seem to point
+to the conclusion that at least some of the feelings by which we know
+that we are expending muscular energy are connected with the initial
+stage of the outgoing nervous process in the motor centres. In other
+pathological conditions the sense of weight by the muscles of the arms
+is similarly confused.
+
+[34] Wundt (_Physiologische Psychologie_, p. 653) would exclude from
+illusions all those errors of sense-perception which have their
+foundation in the normal structure and function of the organs of sense.
+Thus, he would exclude the effects of colour-contrast, _e.g._ the
+apparent modification of two colours in, juxtaposition towards their
+common boundary, which probably arises (according to E. Hering) from
+some mutual influence of the temporary state of activity of adjacent
+retinal elements. To me, however, these appear to be illusions, since
+they may be brought under the head of wrong _interpretations_ of
+sense-impressions. When we see a grey patch as rose-red, as though it
+were so independently of the action of the complementary light
+previously or simultaneously, that is to say, as though it would appear
+rose-red to an eye independently of this action, we surely misinterpret.
+
+[35] Quoted by G.H. Lewes, _loc. cit._, p. 257.
+
+[36] The subject of the perception of movement is too intricate to be
+dealt with fully here. I have only touched on it so far as necessary to
+illustrate our general principle. For a fuller treatment of the subject,
+see the work of Dr. Hoppe, already referred to.
+
+[37] The perception of magnitude is closely connected with that of
+distance, and is similarly apt to take an illusory form. I need only
+refer to the well-known simple optical contrivances for increasing the
+apparent magnitude of objects. I ought, perhaps, to add that I do not
+profess to give a complete account of optical illusions here, but only
+to select a few prominent varieties, with a view to illustrate general
+principles of illusion. For a fuller account of the various mechanical
+arrangements for producing optical illusion, I must refer the reader to
+the writings of Sir D. Brewster and Helmholtz.
+
+[38] Painters are well aware that the colours at the red end of the
+spectrum are apt to appear as advancing, while those of the violet end
+are known as retiring. The appearance of relief given by a gilded
+pattern on a dark blue as ground, is in part referable to the principle
+just referred to. In addition, it appears to involve a difference in the
+action of the muscles of accommodation in the successive adaptations of
+the eye to the most refrangible and the least refrangible rays. (See
+Brücke, _Die Physiologie der Farben_, sec. 17.)
+
+[39] Helmholtz tells us (_Populäre wissenschaftliche Vorträge_, 3tes
+Heft, p. 64) that even in a stereoscopic arrangement the presence of a
+wrong cast shadow sufficed to disturb the illusion.
+
+[40] Among the means of giving a vivid sense of depth to a picture,
+emphasized by Helmholtz, is diminishing magnitude. It is obvious that
+the perceptions of real magnitude and distance are mutually involved.
+When, for example, a picture represents a receding series of objects, as
+animals, trees, or buildings, the sense of the third dimension, is
+rendered much more clear.
+
+[41] A striking example of this was given in a painting, by Andsell, of
+a sportsman in the act of shooting, exhibited in the Royal Academy in
+1879.
+
+[42] This is at least true of all near objects.
+
+[43] Helmholtz remarks _(op. cit._, p. 628) that the difficulty of
+seeing the convex cast as concave is probably due to the presence of the
+cast shadow. This has, no doubt, some effect: yet the consideration
+urged in the text appears to me to be the most important one.
+
+[44] _Populäre wissenschaftliche Vorträge_, 3tes Heft, pp. 71, 72.
+
+[45] See, on this point, some excellent remarks by G.H. Lewes, _Problems
+of Life and Mind_, third series, vol. ii. p. 275.
+
+[46] To some extent this applies to the changes of apparent magnitude
+due to altered position. Thus, we do not attend to the reduction of the
+height of a small object which we are wont to handle, when it is placed
+far below the level of the eye. And hence the error people make in
+judging of the point in the wall or skirting which a hat will reach when
+placed on the ground.
+
+[47] I refer to the experiments made by Exner, Wundt, and others, in
+determining the time elapsing between the giving of a signal to a person
+and the execution of a movement in response. "It is found," says Wundt,
+"by these experiments that the exact moment at which a sense-impression
+is perceived depends on the amount of preparatory self-accommodation of
+attention." (See Wundt, _Physiologische Psychologie_, ch. xix.,
+especially p. 735. _et seq._)
+
+[48] Quoted by Helmholtz, _op. cit._, p. 626.
+
+[49] When the drawing, by its adherence to the laws of perspective, does
+not powerfully determine the eye to see it in one way rather than in the
+other (as in Figs. 5 to 7), the disposition to see the one form rather
+than the other points to differences in the frequency of the original
+forms in our daily experience. At the same time, it is to be observed
+that, after looking at the drawing for a time under each aspect, the
+suggestion now of the one and now of the other forces itself on the mind
+in a curious and unaccountable way.
+
+[50] _Ueber die phantastischen Gesichsterscheinungen_, p. 45.
+
+[51] Another side of histrionic illusion, the reading of the imitated
+feelings into the actors' minds, will be dealt with in a later chapter.
+
+[52] In a finished painting of any size this preparation is hardly
+necessary. In these cases, in spite of the great deviations from truth
+in pictorial representation already touched on, the amount of essential
+agreement is so large and so powerful in its effect that even an
+intelligent animal will experience an illusion. Mr. Romanes sends me an
+interesting account of a dog, that had never been accustomed to
+pictures, having been put into a state of great excitement by the
+introduction of a portrait into a room, on a level with his eye. It is
+not at all improbable that the lower animals, even when sane, are
+frequently the subjects of slight illusion. That animals dream is a fact
+which is observed as long ago as the age of Lucretius.
+
+[53] This kind of illusion is probably facilitated by the fact that the
+eye is often performing slight movements without any clear consciousness
+of them. See what was said about the limits of sensibility, p. 50.
+
+[54] _Mental Physiology_, fourth edit., p. 158.
+
+[55] In persons of very lively imagination the mere representation of an
+object or event may suffice to bring about such a semblance of
+sensation. Thus, M. Taine (_op. cit._, vol. i. p. 94) vouches for the
+assertion that "one of the most exact and lucid of modern novelists,"
+when working out in his imagination the poisoning of one of his
+fictitious characters, had so vivid a gustatory sensation of arsenic
+that he was attacked by a violent fit of indigestion.
+
+[56] Mentioned by Dr. Carpenter (_Mental Physiology_, p. 207), where
+other curious examples are to be found.
+
+[57] See _Annales Médico-Psychologiques_, tom. vi. p. 168, etc.; tom.
+vii. p. 1. etc.
+
+[58] I have already touched on the resonance of a sense-impression when
+the stimulus has ceased to act (see p. 55). The remarks in the text hold
+good of all such after-impressions, in so far as they take the form of
+fully developed percepts. A good example is the recurrence of the images
+of microscopic preparations, to which the anatomist is liable. (See
+Lewes, _Problems of Life and Mind_, third series, vol. ii. p. 299.)
+Since a complete hallucination is supposed to involve the peripheral
+regions of the nerve, the mere fact of shutting the eye would not, it is
+clear, serve as a test of the origin of the illusion.
+
+[59] That subjective sensation may become the starting-point in complete
+hallucination is shown in a curious instance given by Lazarus, and
+quoted by Taine, _op. cit._, vol. i. p. 122, _et seq._ The German
+psychologist relates that, on one occasion in Switzerland, after gazing
+for some time on a chain of snow-peaks, he saw an apparition of an
+absent friend, looking like a corpse. He goes on to explain that this
+phantom was the product of an image of recollection which somehow
+managed to combine itself with the (positive) after-image left by the
+impression of the snow-surface.
+
+[60] For an account of Mr. Galton's researches, see _Mind_, No. xix.
+Compare, however, Professor Bain's judicious observations on these
+results in the next number of _Mind_. The liability of children to take
+images for percepts, is illustrated by the experiences related in a
+curious little work, _Visions_, by E.H. Clarke, M.D. (Boston, U.S.,
+1878), pp. 17, 46, and 212.
+
+[61] A common way of describing the relation of the hallucinatory to
+real objects, is to say that the former appear partly to cover and hide
+the latter.
+
+[62] Griesinger remarks that the forms of the hallucinations of the
+insane rarely depend on sense-disturbances alone. Though these are often
+the starting-point, it is the whole mental complexion of the time which
+gives the direction to the imagination. The common experience of seeing
+rats and mice running about during a fit of _delirium tremens_ very well
+illustrates the co-operation of peripheral impressions not usually
+attended to, and possibly magnified by the morbid state of sensibility
+of the time (in this case flying spots, _muscæ volitantes_), with
+emotional conditions. (See Griesinger, _loc. cit._, p. 96.)
+
+[63] Wundt (_Physiologische Psychologie_, p. 652) tells us of an insane
+woodman who saw logs of wood on all hands in front of the real objects.
+
+[64] It is stated by Baillarger (Mémoires de l'Académie Royale de
+Médicine, tom. xii. p. 273, etc.) that while visual hallucinations are
+more frequent than auditory in healthy life, the reverse relation holds
+in disease. At the same time, Griesinger remarks (_loc. cit._, p. 98)
+that visual hallucinations are rather more common than auditory in
+disease also. This is what we should expect from the number of
+subjective sensations connected with the peripheral organ of vision. The
+greater relative frequency of auditory hallucinations in disease, if
+made out, would seem to depend on the close connection between
+articulate sounds and the higher centres of intelligence, which centres
+are naturally the first to be thrown out of working order. It is
+possible, moreover, that auditory hallucinations are quite as common as
+visual in states of comparative health, though more easily overlooked.
+Professor Huxley relates that he is liable to auditory though not to
+visual hallucinations. (See _Elementary Lessons in Physiology_, p. 267.)
+
+[65] See Baillarger, _Mémoires de l'Académie Royale de Médicine_, tom.
+xii. p. 273, _et seq._
+
+[66] See Baillarger, _Annales Médico-Psychologiques_, tom. vi. p. 168
+_et seq._; also tom. xii. p. 273, _et seq._ Compare Griesinger, _op.
+cit._ In a curious work entitled _Du Démon de Socrate_ (Paris, 1856), M.
+Lélut seeks to prove that the philosopher's admonitory voice was an
+incipient auditory hallucination symptomic of a nascent stage of mental
+alienation.
+
+[67] This is well brought out by Dr. J. Hughlings Jackson, in the papers
+in _Brain_, already referred to.
+
+[68] _Friend_, vol. i. p. 248. The story is referred to by Sir W. Scott
+in his _Demonology and Witchcraft_.
+
+[69] See E.B. Tylor, _Primitive Culture_, ch. xi.; _cf._ Herbert
+Spencer, _Principles of Sociology_, ch. x.
+
+[70] For a fuller account of the different modes of
+dream-interpretation, see my article "Dream," in the ninth edition of
+the _Encyclopædia Britannica_.
+
+[71] For a fuller account of the reaction of dreams on waking
+consciousness, see Paul Radestock, _Schlaf und Traum_. The subject is
+touched on later, under the Illusions of Memory.
+
+[72] For an account of the latest physiological hypotheses as to the
+proximate cause of sleep, see Radestock, _op. cit._, appendix.
+
+[73] Plutarch, Locke, and others give instances of people who never
+dreamt. Lessing asserted of himself that he never knew what it was to
+dream.
+
+[74] The error touched on here will be fully dealt with under Illusions
+of Memory.
+
+[75] For a very full, fair, and thoughtful discussion of this whole
+question, see Radestock, _op. cit._, ch. iv.
+
+[76] This may be technically expressed by saying that the liminal
+intensity (Schwelle) is raised during sleep.
+
+[77] See Wundt, _Physiologische Psychologie_, pp. 188-191.
+
+[78] There is, indeed, sometimes an undertone of critical reflection,
+which is sufficient to produce a feeling of uncertainty and
+bewilderment, and in very rare cases to amount to a vague consciousness
+that the mental experience is a dream.
+
+[79] _Observations on Man_, Part I. ch. iii, sec. 5.
+
+[80] Quoted by Radestock, _op. cit._, p. 110.
+
+[81] _Le Sommeil et les Rêves_, p. 132, _et seq._
+
+[82] _Das Leben des Traumes_, p. 369. Other instances are related by
+Beattie and Abercrombie.
+
+[83] _Le Sommeil et les Rêves_, p. 42, _et seq._
+
+[84] _Beiträge sur Physiognosie und Heautognosie_, p. 256. For other
+cases see H. Meyer, _Physiologie der Nervenfaser_, p. 309; and
+Strümpell, _Die Natur und Entstehung der Träume_, p. 125.
+
+[85] A very clear and full account of these organic sensations, or
+common sensations, has recently appeared from the pen of A. Horwicz in
+the _Vierteljahrsschrift für wissenschaftliche Philosophie_, iv.
+Jahrgang 3tes Heft.
+
+[86] Schopenhauer uses this hypothesis in order to account for the
+apparent reality of dream-illusions. He thinks these internal sensations
+may be transformed by the "intuitive function" of the brain (by means of
+the "forms" of space, time, etc.) into quasi-realities, just as well as
+the subjective sensations of light, sound, etc., which arise in the
+organs of sense in the absence of external stimuli. (See _Versuch über
+das Geisterschen: Werke_, vol. v. p. 244, _et seq._)
+
+[87] _Das Alpdrücken_, pp. 8, 9, 27.
+
+[88] It is this fact which justifies writers in assigning a prognostic
+character to dreams.
+
+[89] A part of the apparent exaggeration in our dream-experiences may be
+retrospective, and due to the effect of the impression of wonder which
+they leave behind them. (See Strümpell, _Die Natur und Entstehung der
+Träume_.)
+
+[90] _Cf._ Radestock, _op. cit._, pp. 131, 132.
+
+[91] I was on one occasion able to observe this process going on in the
+transition from waking to sleeping. I partly fell asleep when suffering
+from toothache. Instantly the successive throbs of pain transformed
+themselves into a sequence of visible movements, which I can only
+vaguely describe as the forward strides of some menacing adversary.
+
+[92] Even the "unconscious impressions" of waking hours, that is to say,
+those impressions which are so fugitive as to leave no psychical trace
+behind, may thus rise into the clear light of consciousness during
+sleep. Maury relates a curious dream of his own, in which there appeared
+a figure that seemed quite strange to him, though he afterwards found
+that he must have been in the habit of meeting the original in a street
+through which he was accustomed to walk (_loc. cit._, p. 124).
+
+[93] See p. 53.
+
+[94] See Maury, _loc. cit._, p. 146.
+
+[95] See what was said respecting the influence of a dominant emotional
+agitation on the interpretation of actual sense-impressions.
+
+[96] It is proved experimentally that the ear has a much closer organic
+connection with the vocal organ than the eye has. Donders found that the
+period required for responding vocally to a sound-signal is less than
+that required for responding in the same way to a light-signal.
+
+[97] On the nature of this impulse, as illustrated in waking and in
+sleep, see the article by Delboeuf, "Le Sommeil et les Rêves," in
+the _Revue Philosophique_, June, 1880, p. 636.
+
+[98] _Physiologische Psychologie_, p. 660.
+
+[99] I may, perhaps, observe, after giving two dreams which have to do
+with mathematical operations, that, though I was very fond of them in my
+college days, I have long ceased to occupy myself with these processes.
+I would add, by way of redeeming my dream-intelligence from a deserved
+charge of silliness, that I once performed a respectable intellectual
+feat when asleep. I put together the riddle, "What might a wooden ship
+say when her side was stove in? Tremendous!" (Tree-mend-us). I was aware
+of having tried to improve on the form of this pun. I am happy to say I
+am not given to punning during waking life, though I had a fit of it
+once. It strikes me that punning, consisting as it does essentially of
+overlooking sense and attending to sound, is just such a debased kind of
+intellectual activity as one might look for in sleep.
+
+[100] See Radestock, _op. cit._, ch. ix.; _Vergleichung des Traumes mit
+dem Wahnsinn_.
+
+[101] For Spinoza's experience, given in his own words, see Mr. F.
+Pollock's _Spinoza_, p. 57; _cf._ what Wundt says on his experience,
+_Physiologische Psychologie_, p. 648, footnote 2.
+
+[102] See an interesting account of "Recent Researches on Hypnotism," by
+G. Stanley Hall, in _Mind_, January, 1881.
+
+[103] I need hardly observe that physiology shows that there is no
+separation of different elementary colour-sensations which are locally
+identical.
+
+[104] This kind of error is, of course, common to all kinds of
+cognition, in so far as they involve comparison. Thus, the presence of
+the excitement of the emotion of wonder at the sight of an unusually
+large object, say a mountain, disposes the mind to look on it as the
+largest of its class. Such illusions come midway between presentative
+and representative illusions. They might, perhaps, be specially marked
+off as illusions of "judgment."
+
+[105] So far as any mental state, though originating in a fusion of
+elements, is now unanalyzable by the best effort of attention, we must
+of course regard it in its present form as simple. This distinction
+between what is simple or complex in its present nature, and what is
+originally so, is sometimes overlooked by psychologists. Whether the
+feelings and ideas here referred to are now simple or complex, cannot, I
+think, yet be very certainly determined. To take the idea of space, I
+find that after practice I recognize the ingredient of muscular feeling
+much better than I did at first. And this exactly answers to Helmholtz's
+contention that elementary sensations as partial tones can be detected
+after practice. Such separate recognition may be said to depend on
+correct representation. On the other hand, it must be allowed that there
+is room for the intuitionist to say that the associationist is here
+reading something into the idea which does not belong to it. It is to be
+added that the illusion which the associationist commonly seeks to
+fasten on his opponent is that of confusing final with original
+simplicity. Thus, he says that, though the idea of space may now to all
+intents and purposes be simple, it was really built up out of many
+distinct elements. More will be said on the relation of questions of
+nature and genesis further on.
+
+[106] I may as well be frank and say that I myself, assuming free-will
+to be an illusion, have tried to trace the various threads of influence
+which have contributed to its remarkable vitality. (See _Sensation and
+Intuition_, ch. v., "The Genesis of the Free-Will Doctrine.")
+
+[107] I purposely leave aside here the philosophical question, whether
+the knowledge of others' feelings is intuitive in the sense of being
+altogether independent of experience, and the manifestation of a
+fundamental belief. The inherited power referred to in the text might,
+of course, be viewed as a transmitted result of ancestral experience.
+
+[108] I here assume, along with G.H. Lewes and other competent dramatic
+critics, that the actor does not and dares not feel what he expresses,
+at least not in the perfectly spontaneous way, and in the same measure
+in which he appears to feel it.
+
+[109] The illusory nature of much of this emotional interpretation of
+music has been ably exposed by Mr. Gurney. (See _The Power of Sound_, p.
+345, _et seq._)
+
+[110] The reader will note that this impulse is complementary to the
+other impulse to view all mental states as analogous to impressions
+produced by external things, on which I touched in the last chapter.
+
+[111] Errors of memory have sometimes been called "fallacies," as, for
+example, by Dr. Carpenter (_Human Physiology_, ch. x.). While preferring
+the term "illusion," I would not forget to acknowledge my indebtedness
+to Dr. Carpenter, who first set me seriously to consider the subject of
+mnemonic error.
+
+[112] From this it would appear to follow that, so far as a percept is
+representative, recollection must be re-representative.
+
+[113] The relation of memory to recognition is very well discussed by M.
+Delboeuf, in connection with a definition of memory given by
+Descartes. (See the article "Le Sommeil et les Rêves," in the _Revue
+Philosophique_, April, 1880, p. 428, _et seq._)
+
+[114] A very interesting account of the most recent physiological theory
+of memory is to be found in a series of articles, bearing the title, "La
+Mémoire comme fait biologique," published in the _Revue Philosophique_,
+from the pen of the editor, M. Th. Ribot. (See especially the _Revue_ of
+May, 1880, pp. 516, _et seq._) M. Ribot speaks of the modification of
+particular nerve-elements as "the static base" of memory, and of the
+formation of nerve-connections by means of which the modified element
+may be re-excited to activity as "the dynamic base of memory" (p. 535).
+
+[115] What constitutes the difference between such a progressive and a
+retrogressive movement is a point that will be considered by-and-by.
+
+[116] It is not easy to say how far exceptional conditions may serve to
+reinstate the seemingly forgotten past. Yet the experiences of dreamers
+and of those who have been recalled to consciousness after partial
+drowning, whatever they may prove with respect to the revivability of
+remote experiences, do not lead us to imagine that the range of our
+definitely localizing memory is a wide one.
+
+[117] _Der Zeitsinn nach Versuchen_, p. 36, _et seq._
+
+[118] _Physiologische Psychologie_, p. 782.
+
+[119] Wundt refers these errors to variations in the state of
+preadjustment of the attention to impressions and representations,
+according as they succeed one another slowly or rapidly. There is little
+doubt that the effects of the state of tension of the apparatus of
+attention, are involved here, though I am disposed to think that Wundt
+makes too much of this circumstance. (See _Physiologische Psychologie_,
+pp. 782, 783. I have given a fuller account of Wundt's theory in _Mind_,
+No. i.)
+
+[120] Strictly speaking, it would occupy more time, since the effort of
+recalling each successive link in the chain would involve a greater
+interval between any two images than that between the corresponding
+experiences.
+
+[121] I need hardly say that there is no sharp distinction between these
+two modes of subjective appreciation. Our estimate of an interval as it
+passes is really made up of a number of renewed anticipations and
+recollections of the successive experiences. Yet we can say broadly that
+this is a prospective estimate, while that which is formed when the
+period has quite expired must be altogether retrospective.
+
+[122] See an interesting paper on "Consciousness of Time," by Mr. G. J.
+Romanes, in _Mind_ (July, 1878).
+
+[123] It is well known that there is, from the first, a gradual falling
+off in the strength of a sensation of light when a moderately bright
+object is looked at.
+
+[124] _Cf._ Hartley, _Observations on Man_, Part I. ch. iii. sec. 4
+(fifth edit., p. 391).
+
+[125] See Dr. Carpenter's _Mental Physiology_, fourth edit, p. 456.
+
+[126] This is, perhaps, what is meant by saying that people recall their
+past enjoyments more readily than their sufferings. Yet much seems to
+turn on temperament and emotional peculiarities. (For a fuller
+discussion of the point, see my _Pessimism_, p. 344.)
+
+[127] The only exception to this that I can think of is to be found in
+the power which I, at least, possess, after looking at a new object, of
+representing it as a familiar one. Yet this may be explained by saying
+that in the case of every object which is clearly apprehended there must
+be vague revivals of _similar_ objects perceived before. Oases in which
+recent experiences tend, owing to their peculiar nature, very rapidly to
+assume the appearance of old events, will be considered presently.
+
+[128] _Mental Physiology_, p. 456.
+
+[129] _Mental Physiology_, second edit., p. 172.
+
+[130] _Loc. cit._, p. 390.
+
+[131] This source of error has not escaped the notice of autobiographers
+themselves. See the remarks of Goethe in the opening passages of his
+_Wahrheit und Dichtung_.
+
+[132] One wonders whether those persons who, in consequence of an injury
+to their brain, periodically pass from a normal into an abnormal
+condition of mind, in each of which there is little or no memory of the
+contents of the other state, complete their idea of personal continuity
+in each state by the same kind of process as that described in the text.
+
+[133] The reader will remark that this condition of clear intellectual
+consciousness, namely, a certain degree of similarity and continuity of
+character in our successive mental states, is complementary to the other
+condition, constant change, already referred to. It may, perhaps, be
+said that all clear consciousness lies between two extremes of excessive
+sameness and excessive difference.
+
+[134] It follows that any great transformation of our environment may
+lead to a partial confusion with respect to self. For not only do great
+and violent changes in our surroundings beget profound changes in our
+feelings and ideas, but since the idea of self is under one of its
+aspects essentially that of a relation to not-self, any great revolution
+in the one term, will confuse the recognition of the other. This fact is
+expressed in the common expression that we "lose ourselves" when in
+unfamiliar surroundings, and the process of orientation, or "taking our
+bearings," fails.
+
+[135] On these disturbances of memory and self-recognition in insanity,
+see Griesinger, _op. cit._, pp. 49-51; also Ribot, "Des Désordres
+Généraux de la Mémoire," in the _Revue Philosophique_, August, 1880. It
+is related by Leuret (_Fragments Psych. sur la Folie_, p. 277) that a
+patient spoke of his former self as "la personne de moi-même."
+
+[136] In the following account of the process of belief and its errors,
+I am going over some of the ground traversed by my essay on _Belief, its
+Varieties and Conditions_ ("Sensation and Intuition," ch. iv.). To this
+essay I must refer the reader for a fuller analysis of the subject.
+
+[137] For an account of the difference of mechanism in memory and
+expectation, see Taine, _De l'Intelligence_, 2ième partie, livre
+premier, ch. ii. sec. 6.
+
+[138] J.S. Mill distinguishes expectation as a radically distinct mode
+of belief from memory, but does not bring out the contrast with respect
+to activity here emphasized (James Mill's _Analysis of the Human Mind_,
+edited by J.S. Mill, p. 411, etc.). For a fuller statement of my view of
+the relation of belief to action, as compared with that of Professor
+Bain, see my earlier work.
+
+[139] For some good remarks on the logical aspects of future events as
+matters of fact, see Mr. Venn's _Logic of Chance_, ch. x.
+
+[140] James Mill's _Analysis of the Human Mind_, edited by J.S. Mill,
+vol. i p. 414, _et seq._
+
+[141] _Principles of Geology_, ch. iii.
+
+[142] To make this rough analysis more complete, I ought, perhaps, to
+include the effect of all the errors of introspection, memory, and
+spontaneous belief, into which the person himself falls, in so far as
+they communicate themselves to others.
+
+[143] In the case of a vain woman thinking herself much more pretty than
+others think her, the error is still more obviously one connected with a
+belief in objective fact.
+
+[144] _The Study of Sociology_, ch. ix.
+
+[145] As a matter of fact, the proportion of accurate knowledge to error
+is far larger in the case of classes than of individuals. Propositions
+with general terms for subject are less liable to be faulty than
+propositions with singular terms for subject.
+
+[146] For a description of each of these extremes of boundless gaiety
+and utter despondency, see Griesinger, _op. cit._, Bk. III. ch. i. and
+ii. The relation of pessimism to pathological conditions is familiar
+enough; less familiar is the relation of unrestrained optimism. Yet
+Griesinger writes that among the insane "boundless hilarity," with "a
+feeling of good fortune," and a general contentment with everything, is
+as frequent as depression and repining (see especially p. 281, also pp.
+64, 65).
+
+[147] It has been seen that, from a purely psychological point of view,
+even what looks at first like pure presentative cognition, as, for
+example, the recognition of a present feeling of the mind, involves an
+ingredient of representation.
+
+[148] See especially what was said about the _rationale_ of illusions of
+perception, pp. 37, 38.
+
+[149] I say "usually," because, as we have seen, there may sometimes be
+a permanent and even an inherited predisposition to active illusion in
+the individual temperament and nervous organization.
+
+[150] See what was said on the nature of passive illusions of sense (pp.
+44, 68, 70, etc.) The logical character of illusion might be brought out
+by saying that it resembles the fallacy which is due to reasoning from
+an approximate generalization as though it were a universal truth. In
+thus identifying illusion and fallacy, I must not be understood to say
+that there is, strictly speaking, any such thing as an unconscious
+reasoning process. On the contrary, I hold that it is a contradiction to
+talk of any _mental_ operation as altogether unconscious. I simply wish
+to show that, by a kind of fiction, illusion may be described as the
+result of a series of steps which, if separately unfolded to
+consciousness (as they no longer are), would correspond to those of a
+process of inference. The fact that illusion arises by a process of
+contraction out of conscious inference seems to justify this use of
+language, even apart from the fact that the nervous processes in the two
+cases are pretty certainly the same.
+
+[151] If we turn from the region of physical to that of moral ideas, we
+see this historical collision between common and individual conviction
+in a yet more impressive form. The teacher of a new moral truth has
+again and again been set down to be an illusionist by a society which
+was itself under the sway of a long-reigning error. As George Eliot
+observes, "What we call illusions are often, in truth, a wider vision of
+past and present realities--a willing movement of a man's soul with the
+larger sweep of the world's forces."
+
+[152] To make this account of the philosophic problem of the
+object-world complete, I ought to touch not only on the distinction
+between the vulgar and the scientific view of material things, but also
+on the distinction, within physical science, between the less and the
+more abstract view roughly represented by molar and molecular physics.
+
+[153] For an excellent account of the distinction between the scientific
+and the philosophic point of view, see Mr. Shadworth Hodgson's
+_Philosophy of Reflection_, Bk. I. chs. i. and iii.; also Bk. III. chs.
+vii. and viii.
+
+[154] I hold, in spite of Berkeley's endeavours to reconcile his
+position with that of common sense, that the popular view does at least
+tend in this direction. That is to say, the every-day habit, when
+considering the external world, of abstracting from particular minds,
+leads on insensibly to that complete detachment of it from mind in
+general which expresses itself in the first stage of philosophic
+reflection, crude realism. The physicist appears to me, both from the
+first essays in Greek "nature-philosophy," as also from the not
+infrequent confusion even to-day between a perfectly safe "scientific
+materialism" and a highly questionable philosophic materialism, to share
+in this tendency to take separate consideration for separate existence.
+Each new stage of abstraction in physical science gives birth to a new
+attempt to find an independent reality, a thing-in-itself, hidden
+further away from sense.
+
+[155] See the interesting autobiographical record of the growth of
+philosophic doubt in the _Première Méditation_ of Descartes.
+
+[156] The appeal is not, as we have seen, invariably from sight to
+touch, but may be in the reverse direction, as in the recognition of the
+duality of the points of a pair of compasses, which seem one to the
+tactual sense.
+
+[157] I might further remark that this "collective experience" includes
+previously detected illusions of ourselves and of others.
+
+[158] M. Taine frankly teaches that what is commonly called accurate
+perception is a "true hallucination" (_De l'Intelligence_, 2ième partie,
+Livre I. ch. i. sec. 3).
+
+[159] It only seems to do so, apart from philosophic assumptions, in
+certain cases where experience testifies to a uniform untrustworthiness
+of the origin. For example, we may, on grounds of matter of fact and
+experience, be disposed to distrust any belief that we recognize as
+springing from an emotional source, from the mind's feelings and wishes.
+
+I may add that a so-called intuitive belief may refer to a matter of
+fact which can be tested by the facts of experience and by scientific
+methods. Thus, for example, the old and now exploded form of the
+doctrine of innate ideas, which declared that children were born with
+certain ideas ready made, might be tested by observation of childhood,
+and reasoning from its general intellectual condition. The same applies
+to the physiological theories of space-perception, supposed to be based
+on Kant's doctrine, put forward in Germany by Johannes Müller and the
+"nativistic school." (See my exposition and criticism of these doctrines
+in _Mind_, April, 1878, pp. 168-178 and 193-195.)
+
+
+
+
+
+
+End of the Project Gutenberg EBook of Illusions, by James Sully
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+
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+Title: Illusions
+       A Psychological Study
+
+Author: James Sully
+
+Release Date: February 21, 2006 [EBook #17815]
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+
+<h1>ILLUSIONS</h1>
+
+<h2><i>A PSYCHOLOGICAL STUDY</i></h2>
+
+
+
+<h4>BY</h4>
+<h3>JAMES SULLY</h3>
+<p class='center'>AUTHOR OF "SENSATION AND INTUITION," "PESSIMISM," ETC.</p>
+
+
+
+<h4>THIRD EDITION</h4>
+
+
+
+<p class='center'>LONDON<br />
+KEGAN PAUL, TRENCH &amp; CO., 1, PATERNOSTER SQUARE<br />
+1887</p>
+
+
+
+
+<p class='center'>(<i>The rights of translation and of reproduction are reserved</i>)</p>
+
+<h4>THE INTERNATIONAL SCIENTIFIC SERIES.</h4>
+
+<h4>VOL. XXXIV.</h4>
+
+
+
+<hr style="width: 65%;" />
+<h2>PREFACE.</h2>
+
+<p>The present volume takes a wide survey of the field of error, embracing
+in its view not only the illusions of sense dealt with in treatises on
+physiological optics, etc., but also other errors familiarly known as
+illusions, and resembling the former in their structure and mode of
+origin. I have throughout endeavoured to keep to a strictly scientific
+treatment, that is to say, the description and classification of
+acknowledged errors, and the explanation of these by a reference to
+their psychical and physical conditions. At the same time, I was not
+able, at the close of my exposition, to avoid pointing out how the
+psychology leads on to the philosophy of the subject. Some of the
+chapters were first roughly sketched out in articles published in
+magazines and reviews; but these have been not only greatly enlarged,
+but, to a considerable extent, rewritten.</p>
+
+<p class='author'>J. S.</p>
+
+<p><span style="margin-left: 1em;"><i>Hampstead, April, 1881.</i></span></p>
+
+
+
+
+<h3>CONTENTS.</h3>
+
+<p>
+<span style="margin-left: 1em;">CHAPTER I.</span><br />
+<br />
+<span style="margin-left: 1em;">THE STUDY OF ILLUSION.</span><br />
+<br />
+<span style="margin-left: 1em;">Vulgar idea of Illusion, <a href='#Page_1'>1</a>, <a href='#Page_2'>2</a>; Psychological treatment of subject, <a href='#Page_3'>3</a>, <a href='#Page_4'>4</a>;</span><br />
+<span style="margin-left: 1em;">definition of Illusion, <a href='#Page_4'>4</a>-<a href='#Page_7'>7</a>; Philosophic extension of idea, <a href='#Page_7'>7</a>, <a href='#Page_8'>8</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER II.</span><br />
+<br />
+<span style="margin-left: 1em;">THE CLASSIFICATION OF ILLUSIONS.</span><br />
+<br />
+<span style="margin-left: 1em;">Popular and Scientific conceptions of Mind, <a href='#Page_9'><b>9</b></a>, <a href='#Page_10'><b>10</b></a>; Illusion and</span><br />
+<span style="margin-left: 1em;">Hallucination, <a href='#Page_11'><b>11</b></a>-<a href='#Page_13'><b>13</b></a>; varieties of Immediate Knowledge, <a href='#Page_13'><b>13</b></a>-<a href='#Page_16'><b>16</b></a>; four-fold</span><br />
+<span style="margin-left: 1em;">division of Illusions, <a href='#Page_16'><b>16</b></a>-<a href='#Page_18'><b>18</b></a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER III.</span><br />
+<br />
+<span style="margin-left: 1em;">ILLUSIONS OF PERCEPTION: GENERAL.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Psychology of Perception</i>:&mdash;The Psychological analysis of Perception, <a href='#Page_19'><b>19</b></a>,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_20'><b>20</b></a>; Sensation and its discrimination, etc., <a href='#Page_20'><b>20</b></a>, <a href='#Page_21'><b>21</b></a>; interpretation of</span><br />
+<span style="margin-left: 1.5em;">Sensation, <a href='#Page_22'><b>22</b></a>, <a href='#Page_23'><b>23</b></a>; construction of material object, <a href='#Page_23'><b>23</b></a>, <a href='#Page_24'><b>24</b></a>; recognition</span><br />
+<span style="margin-left: 1.5em;">of object, specific and individual, <a href='#Page_24'><b>24</b></a>-<a href='#Page_27'><b>27</b></a>; Preperception and</span><br />
+<span style="margin-left: 1.5em;">Perception, <a href='#Page_27'><b>27</b></a>-<a href='#Page_31'><b>31</b></a>; Physiological conditions of Perception, <a href='#Page_31'><b>31</b></a>-<a href='#Page_33'><b>33</b></a>;</span><br />
+<span style="margin-left: 1.5em;">Visual and other Sense-perception, <a href='#Page_33'><b>33</b></a>, <a href='#Page_34'><b>34</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Illusions of Perception</i>:&mdash;Illusion of Perception defined, <a href='#Page_35'><b>35-38</b></a>; sources</span><br />
+<span style="margin-left: 1.5em;">of Sense-illusion, <a href='#Page_38'><b>38-40</b></a>: (a) confusion of Sense-impression, <a href='#Page_40'><b>40-44</b></a>;</span><br />
+<span style="margin-left: 1.5em;">(b) misinterpretation of Sense-impression, <a href='#Page_44'><b>44</b></a>; Passive and Active</span><br />
+<span style="margin-left: 1.5em;">misinterpretation, <a href='#Page_44'><b>44-46</b></a>; Passive Illusions as organically and</span><br />
+<span style="margin-left: 1.5em;">extra-organically conditioned, <a href='#Page_46'><b>46-49</b></a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER IV.</span><br />
+<br />
+<span style="margin-left: 1em;">ILLUSIONS OF PERCEPTION&mdash;<i>continued</i>.</span><br />
+<br />
+<span style="margin-left: 1em;">A. <i>Passive Illusions (a) as determined by the Organism.</i></span><br />
+<span style="margin-left: 1em;"><i>Results of Limits of Sensibility</i>:&mdash;Relation of quantity of Sensation to</span><br />
+<span style="margin-left: 1em;">that of Stimulus, <a href='#Page_50'><b>50-52</b></a>; coalescence of simultaneous Sensations,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_52'><b>52-55</b></a>; after-effect of Stimulation, <a href='#Page_55'><b>55</b></a>, <a href='#Page_56'><b>56</b></a>; effects of prolonged</span><br />
+<span style="margin-left: 1em;">Stimulation, <a href='#Page_56'><b>56-58</b></a>; Specific Energy of Nerves, <a href='#Page_58'><b>58</b></a>, <a href='#Page_59'><b>59</b></a>; localization</span><br />
+<span style="margin-left: 1em;">of Sensation, <a href='#Page_59'><b>59-62</b></a>; Subjective Sensations, <a href='#Page_62'><b>62-64</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Results of Variation of Sensibility</i>:&mdash;Rise and fall of Sensibility, <a href='#Page_64'><b>64-67</b></a>;</span><br />
+<span style="margin-left: 1em;">Par&aelig;sesthesia, <a href='#Page_67'><b>67</b></a>, <a href='#Page_68'><b>68</b></a>; <i>rationale</i> of organically conditioned Illusions,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_68'><b>68</b></a>, <a href='#Page_69'><b>69</b></a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER V.</span><br />
+<br />
+<span style="margin-left: 1em;">ILLUSIONS OF PERCEPTION&mdash;<i>continued</i>.</span><br />
+<br />
+<span style="margin-left: 1em;">A. <i>Passive Illusions (b) as determined by the Environment.</i></span><br />
+<span style="margin-left: 1em;"><i>Exceptional Relation of Stimulus to Organ</i>:&mdash;Displacement of organ, etc.,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_70'><b>70-72</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Exceptional Arrangement of Circumstances in the Environment</i>:&mdash;Misinterpretation</span><br />
+<span style="margin-left: 1em;">of the direction and movement of objects, <a href='#Page_72'><b>72-75</b></a>;</span><br />
+<span style="margin-left: 1em;">misperception of Distance, <a href='#Page_75'><b>75</b></a>, <a href='#Page_76'><b>76</b></a>; Illusions of depth, relief, and</span><br />
+<span style="margin-left: 1em;">solidity in Art, <a href='#Page_77'><b>77-81</b></a>; Illusions connected with the perception of</span><br />
+<span style="margin-left: 1em;">objects through transparent coloured media, <a href='#Page_82'><b>82-84</b></a>; visual transformation</span><br />
+<span style="margin-left: 1em;">of concave into convex form, <a href='#Page_84'><b>84-86</b></a>; false recognition of</span><br />
+<span style="margin-left: 1em;">objects, <a href='#Page_86'><b>86</b></a>, <a href='#Page_87'><b>87</b></a>; inattention to Sense-impression in Recognition,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_87'><b>87-91</b></a>; suggestion taking the direction of familiar recurring experiences,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_91'><b>91</b></a>, <a href='#Page_92'><b>92</b></a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER VI.</span><br />
+<br />
+<span style="margin-left: 1em;">ILLUSIONS OF PERCEPTION&mdash;<i>continued</i>.</span><br />
+<br />
+<span style="margin-left: 1em;">B. <i>Active Illusions.</i></span><br />
+<br />
+<span style="margin-left: 1em;">Preperception and Illusion, <a href='#Page_93'><b>93-95</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Voluntary Preperception</i>:&mdash;Choice of interpretation in the case of visible</span><br />
+<span style="margin-left: 1em;">movement, <a href='#Page_95'><b>95</b></a>, <a href='#Page_96'><b>96</b></a>; and in the case of flat projections of form,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_96'><b>96-98</b></a>; capricious interpretation of obscure impressions, <a href='#Page_99'><b>99</b></a>, <a href='#Page_100'><b>100</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Involuntary Preperception</i>:&mdash;Effects of permanent Predisposition, <a href='#Page_101'><b>101</b></a>, <a href='#Page_102'><b>102</b></a>;</span><br />
+<span style="margin-left: 1em;">effects of partial temporary Preadjustment, <a href='#Page_102'><b>102-105</b></a>; complete Pro-adjustment</span><br />
+<span style="margin-left: 1em;">or Expectation, <a href='#Page_106'><b>106-109</b></a>; subordination of Sense-impression</span><br />
+<span style="margin-left: 1em;">to Preperception, <a href='#Page_109'><b>109-111</b></a>; transition from Illusion to Hallucination,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_111'><b>111</b></a>, <a href='#Page_112'><b>112</b></a>; rudimentary Hallucinations, <a href='#Page_112'><b>112-114</b></a>; developed</span><br />
+<span style="margin-left: 1em;">Hallucinations, <a href='#Page_114'><b>114-116</b></a>; Hallucination in normal life, <a href='#Page_116'><b>116</b></a>, <a href='#Page_117'><b>117</b></a>;</span><br />
+<span style="margin-left: 1em;">Hallucinations of insanity, <a href='#Page_118'><b>118-120</b></a>; gradual development of Sense-illusions,</span><br />
+<span style="margin-left: 1em;">and continuity of normal and abnormal life; <a href='#Page_120'><b>120-123</b></a>;</span><br />
+<span style="margin-left: 1em;">Sanity and Insanity distinguished, <a href='#Page_123'><b>123-126</b></a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER VII.</span><br />
+<br />
+<span style="margin-left: 1em;">DREAMS.</span><br />
+<br />
+<span style="margin-left: 1em;">Mystery of sleep, <a href='#Page_127'><b>127</b></a>, <a href='#Page_128'><b>128</b></a>; theories of Dreams, <a href='#Page_128'><b>128</b></a>, <a href='#Page_129'><b>129</b></a>; scientific</span><br />
+<span style="margin-left: 1em;">explanation of Dreams, <a href='#Page_129'><b>129</b></a>, <a href='#Page_130'><b>130</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Sleep and Dreaming</i>:&mdash;Condition of organism during sleep, <a href='#Page_131'><b>131</b></a>, <a href='#Page_132'><b>132</b></a>;</span><br />
+<span style="margin-left: 1em;">Are the nervous centres ever wholly inactive during sleep? <a href='#Page_132'><b>132-134</b></a>;</span><br />
+<span style="margin-left: 1em;">nature of cerebral activity involved in Dreams, <a href='#Page_134'><b>134-136</b></a>; psychical</span><br />
+<span style="margin-left: 1em;">conditions of Dreams, <a href='#Page_136'><b>136-138</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>The Dream as Illusion</i>:&mdash;External Sense-impressions as excitants of</span><br />
+<span style="margin-left: 1em;">Dream-images, <a href='#Page_139'><b>139-143</b></a>; internal "subjective" stimuli in the sense-organs,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_143'><b>143-145</b></a>; organic sensations, <a href='#Page_145'><b>145-147</b></a>; how sensations are</span><br />
+<span style="margin-left: 1em;">exaggerated in Dream-interpretation, <a href='#Page_147'><b>147-151</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>The Dream as Hallucination</i>:&mdash;Results of direct central stimulation</span><br />
+<span style="margin-left: 1em;"><a href='#Page_151'><b>151-153</b></a>; indirect central stimulation and association, <a href='#Page_153'><b>153-155</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>The Form and Structure of Dreams</i>:&mdash;The incoherence of Dreams explained,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_156'><b>156-161</b></a>; coherence and unity of Dream as effected (a) by</span><br />
+<span style="margin-left: 1em;">coalescence and transformation of images, <a href='#Page_161'><b>161-163</b></a>; (b) by aground-tone</span><br />
+<span style="margin-left: 1em;">of feeling, <a href='#Page_164'><b>164-168</b></a>; (c) by the play of associative dispositions,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_168'><b>168-172</b></a>; (d) by the activities of selective attention stimulated by</span><br />
+<span style="margin-left: 1em;">the rational impulse to connect and to arrange, <a href='#Page_172'><b>172-176</b></a>; examples</span><br />
+<span style="margin-left: 1em;">of Dreams, <a href='#Page_176'><b>176-179</b></a>; limits of intelligence and rational activity in</span><br />
+<span style="margin-left: 1em;">Dreams, <a href='#Page_180'><b>180-182</b></a>; Dreaming and mental disease, <a href='#Page_182'><b>182</b></a>, <a href='#Page_183'><b>183</b></a>; After-dreams</span><br />
+<span style="margin-left: 1em;">and Apparitions, <a href='#Page_183'><b>183-185</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;">NOTE.&mdash;The Hypnotic Condition, <a href='#Page_185'><b>185-188</b></a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER VIII.</span><br />
+<br />
+<span style="margin-left: 1em;">ILLUSIONS OF INTROSPECTION.</span><br />
+<br />
+<span style="margin-left: 1em;">Illusions of Introspection defined, <a href='#Page_189'><b>189-192</b></a>; question of the possibility</span><br />
+<span style="margin-left: 1em;">of illusory Introspection, <a href='#Page_192'><b>192-194</b></a>; incomplete grasp of internal</span><br />
+<span style="margin-left: 1em;">feelings as such, <a href='#Page_194'><b>194-196</b></a>; misobservation of internal feelings: Passive</span><br />
+<span style="margin-left: 1em;">Illusions, <a href='#Page_196'><b>196-199</b></a>; Active Illusions, <a href='#Page_199'><b>199-202</b></a>; malobservation of</span><br />
+<span style="margin-left: 1em;">subjective states, <a href='#Page_202'><b>202-205</b></a>; Illusory Introspection in psychology and</span><br />
+<span style="margin-left: 1em;">philosophy, <a href='#Page_205'><b>205-208</b></a>; value of the Introspective method, <a href='#Page_208'><b>208-211</b></a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER IX.</span><br />
+<br />
+<span style="margin-left: 1em;">OTHER QUASI-PRESENTATIVE ILLUSIONS: ERRORS OF INSIGHT.</span><br />
+<br />
+<span style="margin-left: 1em;">Emotion and Perception, <a href='#Page_212'><b>212</b></a>; &AElig;sthetic Intuition, <a href='#Page_213'><b>213</b></a>; Subjective Impressions</span><br />
+<span style="margin-left: 1em;">of beauty misinterpreted, <a href='#Page_213'><b>213-216</b></a>; analogous Emotional</span><br />
+<span style="margin-left: 1em;">Intuitions, <a href='#Page_216'><b>216</b></a>, <a href='#Page_217'><b>217</b></a>; Insight, its nature, <a href='#Page_217'><b>217-220</b></a>; Passive Illusions</span><br />
+<span style="margin-left: 1em;">of Insight, <a href='#Page_220'><b>220-222</b></a>; Active Illusions of Insight: projection of individual</span><br />
+<span style="margin-left: 1em;">feelings, <a href='#Page_222'><b>222-224</b></a>; the poetic transformation of nature, <a href='#Page_224'><b>224-226</b></a>;</span><br />
+<span style="margin-left: 1em;">special predispositions as falsifying Insight, <a href='#Page_226'><b>226-228</b></a>; value of</span><br />
+<span style="margin-left: 1em;">faculty of Insight, <a href='#Page_228'><b>228-230</b></a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER X.</span><br />
+<br />
+<span style="margin-left: 1em;">ILLUSIONS OF MEMORY.</span><br />
+<br />
+<span style="margin-left: 1em;">Vulgar confidence in Memory, <a href='#Page_231'><b>231-233</b></a>; definition of Memory, <a href='#Page_233'><b>233-235</b></a>;</span><br />
+<span style="margin-left: 1em;">Psychology of Memory, <a href='#Page_235'><b>235-237</b></a>; Physiology of Memory, <a href='#Page_237'><b>237</b></a>, <a href='#Page_238'><b>238</b></a>;</span><br />
+<span style="margin-left: 1em;">Memory as localization in the past, <a href='#Page_238'><b>238-241</b></a>; Illusions of Memory</span><br />
+<span style="margin-left: 1em;">classified, <a href='#Page_241'><b>241-245</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;">(1) <i>Illusions of Time-Perspective:</i>&mdash;</span><br />
+<br />
+<span style="margin-left: 1em;">(a) Definite Localization of events: constant errors in retrospective</span><br />
+<span style="margin-left: 1em;">estimate of time, <a href='#Page_245'><b>245-249</b></a>; varying errors: estimate of duration</span><br />
+<span style="margin-left: 1em;">during a period, <a href='#Page_249'><b>249-251</b></a>; variations in retrospective estimate of</span><br />
+<span style="margin-left: 1em;">duration, <a href='#Page_251'><b>251-256</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;">(b) Indefinite Localization: effect of vividness of mnemonic image</span><br />
+<span style="margin-left: 1em;">on the apparent distance of events, <a href='#Page_256'><b>256-258</b></a>; isolated public events,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_258'><b>258</b></a>, <a href='#Page_259'><b>259</b></a>; active element in errors of Localization, <a href='#Page_259'><b>259-261</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;">(2) <i>Distortions of Memory</i>:&mdash;Transformation of past through forgetfulness,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_261'><b>261-264</b></a>; confusion of distinct recollections, <a href='#Page_264'><b>264-266</b></a>; Active</span><br />
+<span style="margin-left: 1em;">Illusion: influence of present imaginative activity, <a href='#Page_266'><b>266-269</b></a>; exaggeration</span><br />
+<span style="margin-left: 1em;">in recollections of remote experiences, <a href='#Page_269'><b>269</b></a>, <a href='#Page_270'><b>270</b></a>; action of</span><br />
+<span style="margin-left: 1em;">present feeling in transforming past, <a href='#Page_270'><b>270</b></a>, <a href='#Page_271'><b>271</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;">(3) <i>Hallucinations of Memory</i>:&mdash;Their nature, <a href='#Page_271'><b>271-273</b></a>; past dreams taken</span><br />
+<span style="margin-left: 1em;">for external experiences, <a href='#Page_273'><b>273-277</b></a>; past waking imagination taken</span><br />
+<span style="margin-left: 1em;">for external reality, <a href='#Page_277'><b>277-280</b></a>; recollection of prenatal ancestral</span><br />
+<span style="margin-left: 1em;">experience, <a href='#Page_280'><b>280</b></a>, <a href='#Page_281'><b>281</b></a>; filling up gaps in recollection, <a href='#Page_281'><b>281-283</b></a>.</span><br />
+<span style="margin-left: 1em;"><i>Illusions connected with, Personal Identity</i>:&mdash;Illusions of Memory and</span><br />
+<span style="margin-left: 1em;">Sense of identity, <a href='#Page_283'><b>283</b></a>, <a href='#Page_284'><b>284</b></a>; idea of permanent self, how built up,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_285'><b>285-287</b></a>; disturbances of sense of identity, <a href='#Page_287'><b>287-290</b></a>; fallibility and</span><br />
+<span style="margin-left: 1em;">trustworthiness of Memory, <a href='#Page_290'><b>290-292</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;">NOTE.&mdash;Momentary Illusions of Self-consciousness, <a href='#Page_293'><b>293</b></a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER XI.</span><br />
+<br />
+<span style="margin-left: 1em;">ILLUSIONS OF BELIEF.</span><br />
+<br />
+<span style="margin-left: 1em;">Belief as Immediate or Intuitive, <a href='#Page_294'><b>294-296</b></a>; simple and compound Belief, <a href='#Page_296'><b>296</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;">A. <i>Simple Illusory Belief</i>:&mdash;</span><br />
+<br />
+<span style="margin-left: 3em;">(1) Expectation: its nature, <a href='#Page_297'><b>297</b></a>, <a href='#Page_298'><b>298</b></a>; Is Expectation ever intuitive?</span><br />
+<span style="margin-left: 4em;"><a href='#Page_298'><b>298</b></a>; Expectation and Inference from the past, <a href='#Page_299'><b>299-301</b></a>; Expectation</span><br />
+<span style="margin-left: 4em;">of new kinds of experience, <a href='#Page_301'><b>301</b></a>, <a href='#Page_302'><b>302</b></a>; Permanent Expectations</span><br />
+<span style="margin-left: 4em;">of remote events, <a href='#Page_302'><b>302</b></a>; misrepresentation of future duration,</span><br />
+<span style="margin-left: 4em;"><a href='#Page_302'><b>302-305</b></a>; Imaginative transformation of future, <a href='#Page_305'><b>305-307</b></a>.</span><br />
+<br />
+<span style="margin-left: 3em;">(2) Quasi-Expectations: anticipation of extra-personal experiences,</span><br />
+<span style="margin-left: 4em;"><a href='#Page_307'><b>307</b></a>, <a href='#Page_308'><b>308</b></a>; Retrospective Beliefs, <a href='#Page_308'><b>308-312</b></a>.</span><br />
+<br />
+<span style="margin-left: 1em;">B. <i>Compound Illusory Belief</i>:&mdash;</span><br />
+<br />
+<span style="margin-left: 3em;">(1) Representations of permanent things: their structure, <a href='#Page_312'><b>312</b></a>; our</span><br />
+<span style="margin-left: 4em;">representations of others as illusory, <a href='#Page_312'><b>312-315</b></a>; our representation</span><br />
+<span style="margin-left: 4em;">of ourselves as illusory, <a href='#Page_315'><b>315</b></a>; Illusion of self-esteem, <a href='#Page_316'><b>316-318</b></a>;</span><br />
+<span style="margin-left: 4em;">genesis of illusory opinion of self, <a href='#Page_318'><b>318-322</b></a>; Illusion in our</span><br />
+<span style="margin-left: 4em;">representations of classes of things, <a href='#Page_322'><b>322</b></a>, <a href='#Page_323'><b>323</b></a>; and in our views of the</span><br />
+<span style="margin-left: 4em;">world as a whole, <a href='#Page_323'><b>323</b></a>, <a href='#Page_324'><b>324</b></a>; tendency of belief towards divergence,</span><br />
+<span style="margin-left: 4em;"><a href='#Page_325'><b>325</b></a>; and towards convergence, <a href='#Page_326'><b>326</b></a>, <a href='#Page_327'><b>327</b></a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">CHAPTER XII.</span><br />
+<br />
+<span style="margin-left: 1em;">RESULTS.</span><br />
+<br />
+<span style="margin-left: 1em;">Range of Illusion, <a href='#Page_328'><b>328-330</b></a>; nature and causes of Illusion in general,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_331'><b>331-334</b></a>; Illusion identical with Fallacy, <a href='#Page_334'><b>334</b></a>; Illusion as abnormal,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_336'><b>336</b></a>, <a href='#Page_337'><b>337</b></a>; question of common error, <a href='#Page_337'><b>337-339</b></a>; evolutionist's conception</span><br />
+<span style="margin-left: 1em;">of error as maladaptation, <a href='#Page_339'><b>339-344</b></a>; common intuitions</span><br />
+<span style="margin-left: 1em;">tested only by philosophy, <a href='#Page_344'><b>344</b></a>; assumptions of science respecting</span><br />
+<span style="margin-left: 1em;">external reality, etc., <a href='#Page_344'><b>344-346</b></a>; philosophic investigation of these</span><br />
+<span style="margin-left: 1em;">assumptions, <a href='#Page_346'><b>346-348</b></a>; connection between scientific and philosophic</span><br />
+<span style="margin-left: 1em;">consideration of Illusion, <a href='#Page_348'><b>348-350</b></a>; correction of Illusion and its</span><br />
+<span style="margin-left: 1em;">implications, <a href='#Page_351'><b>351</b></a>, <a href='#Page_352'><b>352</b></a>; Fundamental Intuitions and modern psychology,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_352'><b>352</b></a>; psychology as positive science and as philosophy, <a href='#Page_353'><b>353-355</b></a>;</span><br />
+<span style="margin-left: 1em;">points of resemblance between acknowledged Illusions and Fundamental</span><br />
+<span style="margin-left: 1em;">Intuitions, <a href='#Page_355'><b>355</b></a>, <a href='#Page_356'><b>356</b></a>; question of origin, and question of</span><br />
+<span style="margin-left: 1em;">validity, <a href='#Page_356'><b>356</b></a>, <a href='#Page_357'><b>357</b></a>; attitude of scientific mind towards philosophic</span><br />
+<span style="margin-left: 1em;">scepticism, <a href='#Page_357'><b>357-360</b></a>; Persistent Intuitions must be taken as true,</span><br />
+<span style="margin-left: 1em;"><a href='#Page_360'><b>360</b></a>, <a href='#Page_361'><b>361</b></a>.</span><br />
+</p>
+<p><span class='pagenum'><a name="Page_1" id="Page_1">[Pg 1]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER I.</h2>
+
+<h4>THE STUDY OF ILLUSION.</h4>
+
+
+<p>Common sense, knowing nothing of fine distinctions, is wont to draw a
+sharp line between the region of illusion and that of sane intelligence.
+To be the victim of an illusion is, in the popular judgment, to be
+excluded from the category of rational men. The term at once calls up
+images of stunted figures with ill-developed brains, half-witted
+creatures, hardly distinguishable from the admittedly insane. And this
+way of thinking of illusion and its subjects is strengthened by one of
+the characteristic sentiments of our age. The nineteenth century
+intelligence plumes itself on having got at the bottom of medi&aelig;val
+visions and church miracles, and it is wont to commiserate the feeble
+minds that are still subject to these self-deceptions.</p>
+
+<p>According to this view, illusion is something essentially abnormal and
+allied to insanity. And it would seem to follow that its nature and
+origin can be best<span class='pagenum'><a name="Page_2" id="Page_2">[Pg 2]</a></span> studied by those whose speciality it is to observe
+the phenomena of abnormal life. Scientific procedure has in the main
+conformed to this distinction of common sense. The phenomena of illusion
+have ordinarily been investigated by alienists, that is to say,
+physicians who are brought face to face with their most striking forms
+in the mentally deranged.</p>
+
+<p>While there are very good reasons for this treatment of illusion as a
+branch of mental pathology, it is by no means certain that it can be a
+complete and exhaustive one. Notwithstanding the flattering supposition
+of common sense, that illusion is essentially an incident in abnormal
+life, the careful observer knows well enough that the case is far
+otherwise.</p>
+
+<p>There is, indeed, a view of our race diametrically opposed to the
+flattering opinion referred to above, namely, the humiliating judgment
+that all men habitually err, or that illusion is to be regarded as the
+natural condition of mortals. This idea has found expression, not only
+in the cynical exclamation of the misanthropist that most men are fools,
+but also in the cry of despair that sometimes breaks from the weary
+searcher after absolute truth, and from the poet when impressed with the
+unreality of his early ideals.</p>
+
+<p>Without adopting this very disparaging opinion of the intellectual
+condition of mankind, we must recognize the fact that most men are
+sometimes liable to illusion. Hardly anybody is always consistently
+sober and rational in his perceptions and beliefs. A momentary fatigue
+of the nerves, a little mental excitement, a relaxation of the effort of
+attention by which we continually take our bearings with<span class='pagenum'><a name="Page_3" id="Page_3">[Pg 3]</a></span> respect to the
+real world about us, will produce just the same kind of confusion of
+reality and phantasm, which we observe in the insane. To give but an
+example: the play of fancy which leads to a detection of animal and
+other forms in clouds, is known to be an occupation of the insane, and
+is rightly made use of by Shakespeare as a mark of incipient mental
+aberration in Hamlet; and yet this very same occupation is quite natural
+to children, and to imaginative adults when they choose to throw the
+reins on the neck of their phantasy. Our luminous circle of rational
+perception is surrounded by a misty penumbra of illusion. Common sense
+itself may be said to admit this, since the greatest stickler for the
+enlightenment of our age will be found in practice to accuse most of his
+acquaintance at some time or another of falling into illusion.</p>
+
+<p>If illusion thus has its roots in ordinary mental life, the study of it
+would seem to belong to the physiology as much as to the pathology of
+mind. We may even go further, and say that in the analysis and
+explanation of illusion the psychologist may be expected to do more than
+the physician. If, on the one hand, the latter has the great privilege
+of observing the phenomena in their highest intensity, on the other
+hand, the former has the advantage of being familiar with the normal
+intellectual process which all illusion simulates or caricatures. To
+this it must be added that the physician is naturally disposed to look
+at illusion mainly, if not exclusively, on its practical side, that is,
+as a concomitant and symptom of cerebral disease, which it is needful to
+be able to recognize. The psychologist has a different interest in the
+subject,<span class='pagenum'><a name="Page_4" id="Page_4">[Pg 4]</a></span> being specially concerned to understand the mental antecedents
+of illusion and its relation to accurate perception and belief. It is
+pretty evident, indeed, that the phenomena of illusion form a region
+common to the psychologist and the mental pathologist, and that the
+complete elucidation of the subject will need the co-operation of the
+two classes of investigator.</p>
+
+<p>In the present volume an attempt will be made to work out the
+psychological side of the subject; that is to say, illusions will be
+viewed in their relation to the process of just and accurate perception.
+In the carrying out of this plan our principal attention will be given
+to the manifestations of the illusory impulse in normal life. At the
+same time, though no special acquaintance with the pathology of the
+subject will be laid claim to, frequent references will be made to the
+illusions of the insane. Indeed, it will be found that the two groups of
+phenomena&mdash;the illusions of the normal and of the abnormal
+condition&mdash;are so similar, and pass into one another by such insensible
+gradations, that it is impossible to discuss the one apart from the
+other. The view of illusion which will be adopted in this work is that
+it constitutes a kind of border-land between perfectly sane and vigorous
+mental life and dementia.</p>
+
+<p>And here at once there forces itself on our attention the question, What
+exactly is to be understood by the term "illusion"? In scientific works
+treating of the pathology of the subject, the word is confined to what
+are specially known as illusions of the senses, that is to say, to false
+or illusory perceptions. And there is very good reason for this
+limitation, since such<span class='pagenum'><a name="Page_5" id="Page_5">[Pg 5]</a></span> illusions of the senses are the most palpable
+and striking symptoms of mental disease. In addition to this, it must be
+allowed that, to the ordinary reader, the term first of all calls up
+this same idea of a deception of the senses.</p>
+
+<p>At the same time, popular usage has long since extended the term so as
+to include under it errors which do not counterfeit actual perceptions.
+We commonly speak of a man being under an illusion respecting himself
+when he has a ridiculously exaggerated view of his own importance, and
+in a similar way of a person being in a state of illusion with respect
+to the past when, through frailty of memory, he pictures it quite
+otherwise than it is certainly known to have been.</p>
+
+<p>It will be found, I think, that there is a very good reason for this
+popular extension of the term. The errors just alluded to have this in
+common with illusions of sense, that they simulate the form of immediate
+or self-evident cognition. An idea held respecting ourselves or
+respecting our past history does not depend on any other piece of
+knowledge; in other words, is not adopted as the result of a process of
+reasoning. What I believe with reference to my past history, so far as I
+can myself recall it, I believe instantaneously and immediately, without
+the intervention of any premise or reason. Similarly, our notions of
+ourselves are, for the most part, obtained apart from any process of
+inference. The view which a man takes of his own character or claims on
+society he is popularly supposed to receive intuitively by a mere act of
+internal observation. Such beliefs may<span class='pagenum'><a name="Page_6" id="Page_6">[Pg 6]</a></span> not, indeed, have all the
+overpowering force which belongs to illusory perceptions, for the
+intuition of something by the senses is commonly looked on as the most
+immediate and irresistible kind of knowledge. Still, they must be said
+to come very near illusions of sense in the degree of their self-evident
+certainty.</p>
+
+<p>Taking this view of illusion, we may provisionally define it as any
+species of error which counterfeits the form of immediate, self-evident,
+or intuitive knowledge, whether as sense-perception or otherwise.
+Whenever a thing is believed on its own evidence and not as a conclusion
+from something else, and the thing then believed is demonstrably wrong,
+there is an illusion. The term would thus appear to cover all varieties
+of error which are not recognized as fallacies or false inferences. If
+for the present we roughly divide all our knowledge into the two regions
+of primary or intuitive, and secondary or inferential knowledge, we see
+that illusion is false or spurious knowledge of the first kind, fallacy
+false or spurious knowledge of the second kind. At the same time, it is
+to be remembered that this division is only a very rough one. As will
+appear in the course of our investigation, the same error may be called
+either a fallacy or an illusion, according as we are thinking of its
+original mode of production or of the form which it finally assumes; and
+a thorough-going psychological analysis of error may discover that these
+two classes are at bottom very similar.</p>
+
+<p>As we proceed, we shall, I think, find an ample justification for our
+definition. We shall see that such illusions as those respecting
+ourselves or the<span class='pagenum'><a name="Page_7" id="Page_7">[Pg 7]</a></span> past arise by very much the same mental processes as
+those which are discoverable in the production of illusory perceptions;
+and thus a complete psychology of the one class will, at the same time,
+contain the explanation of the other classes.</p>
+
+<p>The reader is doubtless aware that philosophers have still further
+extended the idea of illusion by seeking to bring under it beliefs which
+the common sense of mankind has always adopted and never begun to
+suspect. Thus, according to the idealist, the popular notion (the
+existence of which Berkeley, however, denied) of an external world,
+existing in itself and in no wise dependent on our perceptions of it,
+resolves itself into a grand illusion of sense.</p>
+
+<p>At the close of our study of illusions we shall return to this point. We
+shall there inquire into the connection between those illusions which
+are popularly recognized as such, and those which first come into view
+or appear to do so (for we must not yet assume that there are such)
+after a certain kind of philosophic reflection. And some attempt will be
+made to determine roughly how far the process of dissolving these
+substantial beliefs of mankind into airy phantasms may venture to go.</p>
+
+<p>For the present, however, these so-called illusions in philosophy will
+be ignored. It is plain that illusion exists only in antithesis to real
+knowledge. This last must be assumed as something above all question.
+And a rough and provisional, though for our purpose sufficiently
+accurate, demarcation of the regions of the real and the illusory seems
+to coincide with the line which common sense draws between what all
+normal<span class='pagenum'><a name="Page_8" id="Page_8">[Pg 8]</a></span> men agree in holding and what the individual holds, whether
+temporarily or permanently, in contradiction to this. For our present
+purpose the real is that which is true for all. Thus, though physical
+science may tell us that there is nothing corresponding to our
+sensations of colour in the world of matter and motion which it
+conceives as surrounding us; yet, inasmuch as to all men endowed with
+the normal colour-sense the same material objects appear to have the
+same colour, we may speak of any such perception as practically true,
+marking it off from those plainly illusory perceptions which are due to
+some subjective cause, as, for example, fatigue of the retina.</p>
+
+<p>To sum up: in treating of illusions we shall assume, what science as
+distinguished from philosophy is bound to assume, namely, that human
+experience is consistent; that men's perceptions and beliefs fall into a
+consensus. From this point of view illusion is seen to arise through
+some exceptional feature in the situation or condition of the
+individual, which, for the time, breaks the chain of intellectual
+solidarity which under ordinary circumstances binds the single member to
+the collective body. Whether the common experience which men thus obtain
+is rightly interpreted is a question which does not concern us here. For
+our present purpose, which is the determination and explanation of
+illusion as popularly understood, it is sufficient that there is this
+general consensus of belief, and this may provisionally be regarded as
+at least practically true.<span class='pagenum'><a name="Page_9" id="Page_9">[Pg 9]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER II.</h2>
+
+<h4>THE CLASSIFICATION OF ILLUSIONS.</h4>
+
+
+<p>If illusion is the simulation of immediate knowledge, the most obvious
+mode of classifying illusions would appear to be according to the
+variety of the knowledge which they simulate.</p>
+
+<p>Now, the popular psychology that floats about in the ordinary forms of
+language has long since distinguished certain kinds of unreasoned or
+uninferred knowledge. Of these the two best known are perception and
+memory. When I see an object before me, or when I recall an event in my
+past experience, I am supposed to grasp a piece of knowledge directly,
+to know something immediately, and not through the medium of something
+else. Yet I know differently in the two cases. In the first I know by
+what is called a presentative process, namely, that of sense-perception;
+in the second I know by a representative process, namely, that of
+reproduction, or on the evidence of memory. In the one case the object
+of cognition is present to my perceptive faculties; in the other it is
+recalled by the power of memory.</p>
+
+<p>Scientific psychology tends, no doubt, to break down some of these
+popular distinctions. Just as the zoologist<span class='pagenum'><a name="Page_10" id="Page_10">[Pg 10]</a></span> sometimes groups together
+varieties of animals which the unscientific eye would never think of
+connecting, so the psychologist may analyze mental operations which
+appear widely dissimilar to the popular mind, and reduce them to one
+fundamental process. Thus recent psychology draws no sharp distinction
+between perception and recollection. It finds in both very much the same
+elements, though combined in a different way. Strictly speaking, indeed,
+perception must be defined as a presentative-representative operation.
+To the psychologist it comes to very much the same thing whether, for
+example, on a visit to Switzerland, our minds are occupied in
+<i>perceiving</i> the distance of a mountain or in <i>remembering</i> some
+pleasant excursion which we made to it on a former visit. In both cases
+there is a reinstatement of the past, a reproduction of earlier
+experience, a process of adding to a present impression a product of
+imagination&mdash;taking this word in its widest sense. In both cases the
+same laws of reproduction or association are illustrated.</p>
+
+<p>Just as a deep and exhaustive analysis of the intellectual operations
+thus tends to identify their various forms as they are distinguished by
+the popular mind, so a thorough investigation of the flaws in these
+operations, that is to say, the counterfeits of knowledge, will probably
+lead to an identification of the essential mental process which
+underlies them. It is apparent, for example, that, whether a man
+<i>projects</i> some figment of his imagination into the external world,
+giving it, present material reality, or whether (if I may be allowed the
+term) he <i>retrojects</i> it into the dim region of the past, and takes it
+for a reality that has been<span class='pagenum'><a name="Page_11" id="Page_11">[Pg 11]</a></span> he is committing substantially the same
+blunder. The source of the illusion in both cases is one and the same.</p>
+
+<p>It might seem to follow from this that a scientific discussion of the
+subject would overlook the obvious distinction between illusions of
+perception and those of memory; that it would attend simply to
+differences in the mode of origination of the illusion, whatever its
+external form. Our next step, then, would appear to be to determine
+these differences in the mode of production.</p>
+
+<p>That there are differences in the origin and source of illusion is a
+fact which has been fully recognized by those writers who have made a
+special study of sense-illusions. By these the term illusion is commonly
+employed in a narrow, technical sense, and opposed to hallucination. An
+illusion, it is said, must always have its starting-point in some actual
+impression, whereas a hallucination has no such basis. Thus it is an
+illusion when a man, under the action of terror, takes a stump of a
+tree, whitened by the moon's rays, for a ghost. It is a hallucination
+when an imaginative person so vividly pictures to himself the form of
+some absent friend that, for the moment, he fancies himself actually
+beholding him. Illusion is thus a partial displacement of external fact
+by a fiction of the imagination, while hallucination is a total
+displacement.</p>
+
+<p>This distinction, which has been adopted by the majority of recent
+alienists<a name="FNanchor_1_1" id="FNanchor_1_1"></a><a href="#Footnote_1_1" class="fnanchor">[1]</a>, is a valuable one, and<span class='pagenum'><a name="Page_12" id="Page_12">[Pg 12]</a></span> must not be lost sight of here. It
+would seem, from a psychological point of view, to be an important
+circumstance in the genesis of a false perception whether the
+intellectual process sets out from within or from without. And it will
+be found, moreover, that this distinction may be applied to all the
+varieties of error which I propose to consider. Thus, for example, it
+will be seen further on that a false recollection may set out either
+from the idea of some actual past occurrence or from a present product
+of the imagination.</p>
+
+<p>It is to be observed, however, that the line of separation between
+illusion and hallucination, as thus defined, is a very narrow one. In by
+far the largest number of hallucinations it is impossible to prove that
+there is no modicum of external agency co-operating in the production of
+the effect. It is presumable, indeed, that many, if not all,
+hallucinations have such a basis of fact. Thus, the madman who projects
+his internal thoughts outwards in the shape of external voices may, for
+aught we know, be prompted to do so in part by faint impressions coming
+from the ear, the result of those slight stimulations to which the organ
+is always exposed, even in profound silence, and which in his case
+assume an exaggerated intensity. And even if it is clearly made out that
+there are hallucinations in the strict sense, that is to say, false
+perceptions which are wholly due to internal causes, it must be conceded
+that illusion shades off into hallucination by steps which it is
+impossible for science to mark. In<span class='pagenum'><a name="Page_13" id="Page_13">[Pg 13]</a></span> many cases it must be left an open
+question whether the error is to be classed as an illusion or as a
+hallucination.<a name="FNanchor_2_2" id="FNanchor_2_2"></a><a href="#Footnote_2_2" class="fnanchor">[2]</a></p>
+
+<p>For these reasons, I think it best not to make the distinction between
+illusion and hallucination the leading principle of my classification.
+However important psychologically, it does not lend itself to this
+purpose. The distinction must be kept in view and illustrated as far as
+possible. Accordingly, while in general following popular usage and
+employing the term illusion as the generic name, I shall, when
+convenient, recognize the narrow and technical sense of the term as
+answering to a species co-ordinate with hallucination.</p>
+
+<p>Departing, then, from what might seem the ideally best order of
+exposition, I propose, after all, to set out with the simple popular
+scheme of faculties already referred to. Even if they are,
+psychologically considered, identical operations, perception and memory
+are in general sufficiently marked off by a speciality in the form of
+the operation. Thus, while memory is the reproduction of something with
+a special reference of consciousness to its past existence, perception
+is the reproduction of something with a special reference to its present
+existence as a part of the presented object. In other words, though
+largely <i>representative</i> when viewed as to its origin, perception is
+<i>presentative</i> in relation to the object which is supposed to be
+im<span class='pagenum'><a name="Page_14" id="Page_14">[Pg 14]</a></span>mediately present to the mind at the moment.<a name="FNanchor_3_3" id="FNanchor_3_3"></a><a href="#Footnote_3_3" class="fnanchor">[3]</a> Hence the convenience
+of recognizing the popular classification, and of making it our
+starting-point in the present case.</p>
+
+<p>All knowledge which has any appearance of being directly reached,
+immediate, or self-evident, that is to say, of not being inferred from
+other knowledge, may be divided into four principal varieties: Internal
+Perception or Introspection of the mind's own feelings;
+External Perception; Memory; and Belief, in so far as it simulates the
+form of direct knowledge. The first is illustrated in a man's
+consciousness of a present feeling of pain or pleasure. The second and
+the third kinds have already been spoken of, and are too familiar to
+require illustration. It is only needful to remark here that, under
+perception, or rather in close conjunction with it, I purpose dealing
+with the knowledge of other's feelings, in so far as this assumes the
+aspect of immediate knowledge. The term belief is here used to include
+expectations and any other kinds of conviction that do not fall under
+one of the other heads. An instance of a seemingly immediate belief
+would be a prophetic prevision of a coming disaster, or a man's
+unreasoned persuasion as to his own powers of performing a difficult
+task.</p>
+
+<p>It is, indeed, said by many thinkers that there are no legitimate
+immediate beliefs; that all our expectations and other convictions about
+things, in so far as they are sound, must repose on other genuinely
+immediate<span class='pagenum'><a name="Page_15" id="Page_15">[Pg 15]</a></span> knowledge, more particularly sense-perception and memory.
+This difficult question need not be discussed here. It is allowed by all
+that there is a multitude of beliefs which we hold tenaciously and on
+which we are ready to act, which, to the mature mind, wear the
+appearance of intuitive truths, owing their cogency to nothing beyond
+themselves. A man's belief in his own merits, however it may have been
+first obtained, is as immediately assured to him as his recognition of a
+real object in the act of sense-perception. It may be added that many of
+our every-day working beliefs about the world in which we live, though
+presumably derived from memory and perception, tend to lose all traces
+of their origin, and to simulate the aspect of intuitions. Thus the
+proposition that logicians are in the habit of pressing on our
+attention, that "Men are mortal," seems, on the face of it, to common
+sense to be something very like a self-evident truth, not depending on
+any particular facts of experience.</p>
+
+<p>In calling these four forms of cognition immediate, I must not, however,
+be supposed to be placing them on the same logical level. It is plain,
+indeed, to a reflective mind that, though each may be called immediate
+in this superficial sense, there are perceptible differences in the
+degree of their immediacy. Thus it is manifest, after a moment's
+reflection, that expectation, so far as it is just, is not primarily
+immediate in the sense in which purely presentative knowledge is so,
+since it can be shown to follow from something else. So a general
+proposition, though through familiarity and innumerable illustrations it
+has acquired a self-evident character, is seen with a very little
+inspection to be<span class='pagenum'><a name="Page_16" id="Page_16">[Pg 16]</a></span> less fundamentally and essentially so than the
+proposition, "I am now feeling pain;" and it will be found that even
+with respect to memory, when the remembered event is at all remote, the
+process of cognition approximates to a mediate operation, namely, one of
+inference. What the relative values of these different kinds of
+immediate knowledge are is a point which will have to be touched on at
+the end of our study. Here it must suffice to warn the reader against
+the supposition that this value is assumed to be identical.</p>
+
+<p>It might seem at a first glance to follow from this four-fold scheme of
+immediate or quasi-immediate knowledge that there are four varieties of
+illusion. And this is true in the sense that these four heads cover all
+the main varieties of illusion. If there are only four varieties of
+knowledge which can lay any claim to be considered immediate, it must be
+that every illusion will simulate the form of one of these varieties,
+and so be referable to the corresponding division.</p>
+
+<p>But though there are conceivably these four species of illusion, it does
+not follow that there are any actual instances of each class
+forthcoming. This we cannot determine till we have investigated the
+nature and origin of illusory error. For example, it might be found that
+introspection, or the immediate inspection of our own feelings or mental
+states, does not supply the conditions necessary to the production of
+such error. And, indeed, it is probable that most persons, antecedently
+to inquiry, would be disposed to say that to fall into error in the
+observation of what is actually going on in our own minds is
+impossible.<span class='pagenum'><a name="Page_17" id="Page_17">[Pg 17]</a></span></p>
+
+<p>With the exception of this first division, however, this scheme may
+easily be seen to answer to actual phenomena. That there are illusions
+of perception is obvious, since it is to the errors of sense that the
+term illusion has most frequently been confined. It is hardly less
+evident that there are illusions of memory. The peculiar difficulty of
+distinguishing between a past real event and a mere phantom of the
+imagination, illustrated in the exclamation, "I either saw it or dreamt
+it," sufficiently shows that memory is liable to be imposed on. Finally,
+it is agreed on by all that the beliefs we are wont to regard as
+self-evident are sometimes erroneous. When, for example, an imaginative
+woman says she knows, by mere intuition, that something interesting is
+going to happen, say the arrival of a favourite friend, she is plainly
+running the risk of being self-deluded. So, too, a man's estimate of
+himself, however valid for him, may turn out to be flagrantly false.</p>
+
+<p>In the following discussion of the subject I shall depart from the above
+order in so far as to set out with illusions of sense-perception. These
+are well ascertained, forming, indeed, the best-marked variety. And the
+explanation of these has been carried much further than that of the
+others. Hence, according to the rule to proceed from the known to the
+unknown, there will be an obvious convenience in examining these first
+of all. After having done this, we shall be in a position to inquire
+whether there is anything analogous in the region of introspection or
+internal perception. Our study of the errors of sense-perception will,
+moreover, prove the best preparation for<span class='pagenum'><a name="Page_18" id="Page_18">[Pg 18]</a></span> an inquiry into the nature and
+mode of production of the remaining two varieties.<a name="FNanchor_4_4" id="FNanchor_4_4"></a><a href="#Footnote_4_4" class="fnanchor">[4]</a></p>
+
+<p>I would add that, in close connection with the first division, illusions
+of perception, I shall treat the subtle and complicated phenomena of
+dreams. Although containing elements which ought, according to
+strictness, to be brought under one of the other heads, they are, as
+their common appellation, "visions," shows, largely simulations of
+external, and more especially visual, perception.</p>
+
+<p>Dreams are no doubt sharply marked off from illusions of
+sense-perception by a number of special circumstances. Indeed, it may be
+thought that they cannot be adequately treated in a work that aims
+primarily at investigating the illusions of normal life, and should
+rather be left to those who make the pathological side of the subject
+their special study. Yet it may, perhaps, be said that in a wide sense
+dreams are a feature of normal life. And, however this be, they have
+quite enough in common with other illusions of perception to justify us
+in dealing with them in close connection with these.<span class='pagenum'><a name="Page_19" id="Page_19">[Pg 19]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER III.</h2>
+
+<h4>ILLUSIONS OF PERCEPTION: GENERAL.</h4>
+
+
+<p>The errors with which we shall be concerned in this chapter are those
+which are commonly denoted by the term illusion, that is to say, those
+of sense. They are sometimes called deceptions of the senses; but this
+is a somewhat loose expression, suggesting that we can be deceived as to
+sensation itself, though, as we shall see later on, this is only true in
+a very restricted meaning of the phrase. To speak correctly,
+sense-illusions must be said to arise by a simulation of the form of
+just and accurate perceptions. Accordingly, we shall most frequently
+speak of them as illusions of perception.</p>
+
+<p>In order to investigate the nature of any kind of error, it is needful
+to understand the kind of knowledge it imitates, and so we must begin
+our inquiry into the nature of illusions of sense by a brief account of
+the psychology of perception; and, in doing this, we shall proceed best
+by regarding this operation in its most complete form, namely, that of
+visual perception.</p>
+
+<p>I may observe that in this analysis of perception I shall endeavour to
+keep to known facts, namely, the<span class='pagenum'><a name="Page_20" id="Page_20">[Pg 20]</a></span> psychical phenomena or events which
+can be seen by the methods of scientific psychology to enter into the
+mental content called the percept. I do not now inquire whether such an
+analysis can help us to understand all that is meant by perception. This
+point will have to be touched later on. Here it is enough to say that,
+whatever our philosophy of perception may be, we must accept the
+psychological fact that the concrete mental state in the act of
+perception is built up out of elements, the history of which can be
+traced by the methods of mental science.</p>
+
+
+<p class='center'><i>Psychology of Perception.</i></p>
+
+<p>Confining ourselves for the present to the mental, as distinguished from
+the physical, side of the operation, we soon find that perception is not
+so simple a matter as it might at first seem to be. When a man on a hot
+day looks at a running stream and "sees" the delicious coolness, it is
+not difficult to show that he is really performing an act of mental
+synthesis, or imaginative construction. To the sense-impression<a name="FNanchor_5_5" id="FNanchor_5_5"></a><a href="#Footnote_5_5" class="fnanchor">[5]</a> which
+his eye now gives him, he adds something which past experience has
+bequeathed to his mind. In perception, the material of sensation is
+acted on by the mind, which embodies in its present attitude all the
+results of its past growth. Let us look at this process of synthesis a
+little more closely.</p>
+
+<p>When a sensation arises in the mind, it may, under<span class='pagenum'><a name="Page_21" id="Page_21">[Pg 21]</a></span> certain
+circumstances, go unattended to. In that case there is no perception.
+The sensation floats in the dim outer regions of consciousness as a
+vague feeling, the real nature and history of which are unknown. This
+remark applies not only to the undefined bodily sensations that are
+always oscillating about the threshold of obscure consciousness, but to
+the higher sensations connected with the special organs of perception.
+The student in optics soon makes the startling discovery that his field
+of vision has all through his life been haunted with weird shapes which
+have never troubled the serenity of his mind just because they have
+never been distinctly attended to.</p>
+
+<p>The immediate result of this process of directing the keen glance of
+attention to a sensation is to give it greater force and distinctness.
+By attending to it we discriminate it from other feelings present and
+past, and classify it with like sensations previously received. Thus, if
+I receive a visual impression of the colour orange, the first
+consequence of attending to it is to mark it off from other
+colour-impressions, including those of red and yellow. And in
+recognizing the peculiar quality of the impression by applying to it the
+term orange, I obviously connect it with other similar sensations called
+by the same name. If a sensation is perfectly new, there cannot, of
+course, be this process of classifying, and in this case the closely
+related operation of discriminating it from other sensations is less
+exactly performed. But it is hardly necessary to remark that, in the
+mind of the adult, under ordinary circumstances, no perfectly new
+sensation ever occurs.<span class='pagenum'><a name="Page_22" id="Page_22">[Pg 22]</a></span></p>
+
+<p>When the sensation, or complex sensation, is thus defined and
+recognized, there follows the process of interpretation, by which I mean
+the taking up of the impression as an element into the complex mental
+state known as a percept. Without going into the philosophical question
+of what this process of synthesis exactly means, I may observe that, by
+common consent, it takes place to a large extent by help of a
+reproduction of sensations of various kinds experienced in the past.
+That is to say, the details in this act of combination are drawn from
+the store of mental recollections to which the growing mind is ever
+adding. In other words, the percept arises through a fusion of an actual
+sensation with mental representations or "images" of sensation.<a name="FNanchor_6_6" id="FNanchor_6_6"></a><a href="#Footnote_6_6" class="fnanchor">[6]</a> Every
+element of the object that we thus take up in the act of perception, or
+put into the percept, as its actual size, distance, and so on, will be
+found to make itself known to us through mental images or revivals of
+past experiences, such as those we have in handling the object, moving
+to and from it, etc. It follows that if this is an essential ingredient
+in the act of perception, the process closely resembles an act of
+inference; and, indeed, Helmholtz distinctly calls the perception of
+distance an uncon<span class='pagenum'><a name="Page_23" id="Page_23">[Pg 23]</a></span>scious inference or a mechanically performed act of
+judgment.</p>
+
+<p>I have hinted that these recovered sensations include the feelings we
+experience in connection with muscular activity, as in moving our limbs,
+resisting or lifting heavy bodies, and walking to a distant object.
+Modern psychology refers the eye's instantaneous recognition of the most
+important elements of an object (its essential or "primary" qualities)
+to a reinstatement of such simple experiences as these. It is, indeed,
+these reproductions which are supposed to constitute the substantial
+background of our percepts.</p>
+
+<p>Another thing worth noting with respect to this process of filling up a
+sense-impression is that it draws on past sensations of the eye itself.
+Thus, when I look at the figure of an acquaintance from behind, my
+reproductive visual imagination supplies a representation of the
+impressions I am wont to receive when the more interesting aspect of the
+object, the front view, is present to my visual sense.<a name="FNanchor_7_7" id="FNanchor_7_7"></a><a href="#Footnote_7_7" class="fnanchor">[7]</a></p>
+
+<p>We may distinguish between different steps in the full act of visual
+recognition. First of all comes the construction of a material object of
+a particular figure and size, and at a particular distance; that is to
+say, the recognition of a tangible thing having certain simple
+space-properties, and holding a certain relation to other objects, and
+more especially our own body, in space. This is the bare perception of
+an object, which always takes place even in the case of perfectly new<span class='pagenum'><a name="Page_24" id="Page_24">[Pg 24]</a></span>
+objects, provided they are seen with any degree of distinctness. It is
+to be added that the reference of a sensation of light or colour to such
+an object involves the inclusion of a quality answering to the
+sensation, as brightness, or blue colour, in the thing thus intuited.</p>
+
+<p>This part of the process of filling in, which is the most instantaneous,
+automatic, and unconscious, may be supposed to answer to the most
+constant and therefore the most deeply organized connections of
+experience; for, speaking generally, we never have an impression of
+colour, except when there are circumstances present which are fitted to
+yield us those simple muscular and tactual experiences through which the
+ideas of a particular form, size, etc., are pretty certainly obtained.</p>
+
+<p>The second step in this process of presentative construction is the
+recognition of an object as one of a class of things, for example,
+oranges, having certain special qualities, as a particular taste. In
+this step the connections of experience are less deeply organized, and
+so we are able to some extent, by reflection, to recognize it as a kind
+of intellectual working up of the materials supplied us by the past. It
+is to be noted that this process of recognition involves a compound
+operation of classifying impressions as distinguished from that simple
+operation by which a single impression, such as a particular colour, is
+known. Thus the recognition of such an object as an orange takes place
+by a rapid classing of a multitude of passive sensations of colour,
+light, and shade, and those active or muscular sensations which are
+supposed to enter into the visual perception of form.<span class='pagenum'><a name="Page_25" id="Page_25">[Pg 25]</a></span></p>
+
+<p>A still less automatic step in the process of visual recognition is that
+of identifying individual objects, as Westminster Abbey, or a friend,
+John Smith. The amount of experience that is here reproduced may be very
+large, as in the case of recognizing a person with whom we have had a
+long and intimate acquaintance.</p>
+
+<p>If the recognition of an object as one of a class, for example, an
+orange, involves a compound process of classing impressions, that of an
+individual object involves a still more complicated process. The
+identification of a friend, simple as this operation may at first
+appear, really takes place by a rapid classing of all the salient
+characteristic features which serve as the visible marks of that
+particular person.</p>
+
+<p>It is to be noted that each kind of recognition, specific and
+individual, takes place by a consciousness of likeness amid unlikeness.
+It is obvious that a new individual object has characters not shared in
+by other objects previously inspected. Thus, we at once class a man with
+a dark-brown skin, wearing a particular garb, as a Hindoo, though he may
+differ in a host of particulars from the other Hindoos that we have
+observed. In thus instantly recognizing him as a Hindoo, we must, it is
+plain, attend to the points of similarity, and overlook for the instant
+the points of dissimilarity. In the case of individual identification,
+the same thing happens. Strictly speaking, no object ever appears
+exactly the same to us on two occasions. Apart from changes in the
+object itself, especially in the case of living beings, there are
+varying effects of illumination, of position in relation to the eye, of
+distance, and so on, which very distinctly affect the visual impression<span class='pagenum'><a name="Page_26" id="Page_26">[Pg 26]</a></span>
+at different times. Yet the fact of our instantly recognizing a familiar
+object in spite of these fluctuations of appearance, proves that we are
+able to overlook a very considerable amount of diversity when a certain
+amount of likeness is present.</p>
+
+<p>It is further to be observed that in these last stages of perception we
+approach the boundary line between perception and inference. To
+recognize an object as one of a class is often a matter of conscious
+reflection and judgment, even when the class is constituted by obvious
+material qualities which the senses may be supposed to apprehend
+immediately. Still more clearly does perception pass into inference when
+the class is constituted by less obvious qualities, which require a
+careful and prolonged process of recollection, discrimination, and
+comparison, for their recognition. Thus, to recognize a man by certain
+marks of gesture and manner as a military man or a Frenchman, though
+popularly called a perception, is much more of an unfolded process of
+conscious inference. And what applies to specific recognition applies
+still more forcibly to individual recognition, which is often a matter
+of very delicate conscious comparison and judgment. To say where the
+line should be drawn here between perception and observation on the one
+hand, and inference on the other, is clearly impossible. Our whole study
+of the illusions of perception will serve to show that the one shades
+off into the other too gradually to allow of our drawing a hard and fast
+line between them.</p>
+
+<p>Finally, it is to be noted that these last stages of perception bring us
+near the boundary line which separates objective experience as common
+and universal,<span class='pagenum'><a name="Page_27" id="Page_27">[Pg 27]</a></span> and subjective or variable experience as confined to one
+or to a few. In the bringing of the object under a certain class of
+objects there is clearly room for greater variety of individual
+perception. For example, the ability to recognize a man as a Frenchman
+turns on a special kind of previous experience. And this transition from
+the common or universal to the individual experience is seen yet more
+plainly in the case of individual recognition. To identify an object,
+say a particular person, commonly presupposes some previous experience
+or knowledge of this object, and the existence in the past of some
+special relation of the recognizer to the recognized, if only that of an
+observer. In fact, it is evident that in this mode of recognition we
+have the transition from common perception to individual
+recollection.<a name="FNanchor_8_8" id="FNanchor_8_8"></a><a href="#Footnote_8_8" class="fnanchor">[8]</a></p>
+
+<p>While we may thus distinguish different steps in the process of visual
+recognition, we may make a further distinction, marking off a passive
+and an active stage in the process. The one may be called the stage of
+preperception, the other that of perception proper.<a name="FNanchor_9_9" id="FNanchor_9_9"></a><a href="#Footnote_9_9" class="fnanchor">[9]</a> In the first the
+mind holds itself in a passive attitude, except in so far as the
+energies of external attention are involved. The impression here awakens
+the mental images which answer to past experiences according to the
+well-known laws of association. The interpretative image which is to
+transform the impres<span class='pagenum'><a name="Page_28" id="Page_28">[Pg 28]</a></span>sion into a percept is now being formed by a mere
+process of suggestion.</p>
+
+<p>When the image is thus formed, the mind may be said to enter upon a more
+active stage, in which it now views the impression through the image, or
+applies this as a kind of mould or framework to the impression. This
+appears to involve an intensification of the mental image, transforming
+it from a representative to a presentative mental state, making it
+approximate somewhat to the full intensity of the sensation. In many of
+our instantaneous perceptions these two stages are indistinguishable to
+consciousness. Thus, in most cases, the recognition of size, distance,
+etc., takes place so rapidly that it is impossible to detect the two
+phases here separated. But in the classification of an object, or the
+identification of an individual thing, there is often an appreciable
+interval between the first reception of the impression and the final
+stage of complete recognition. And here it is easy to distinguish the
+two stages of preperception and perception. The interpretative image is
+slowly built up by the operation of suggestion, at the close of which
+the impression is suddenly illumined as by a flash of light, and takes a
+definite, precise shape.</p>
+
+<p>Now, it is to be noted that the process of preperception will be greatly
+aided by any circumstance that facilitates the construction of the
+particular interpretative image required. Thus, the more frequently a
+similar process of perception has been performed in the past, the more
+ready will the mind be to fall into the particular way of interpreting
+the impression. As G.H. Lewes well remarks, "The artist sees details<span class='pagenum'><a name="Page_29" id="Page_29">[Pg 29]</a></span>
+where to other eyes there is a vague or confused mass; the naturalist
+sees an animal where the ordinary eye only sees a form." This is but one
+illustration of the seemingly universal mental law, that what is
+repeatedly done will be done more and more easily.</p>
+
+<p>The process of preperception may be shortened, not only by means of a
+<i>permanent</i> disposition to frame the required interpretative scheme, the
+residuum of past like processes, but also by means of any <i>temporary</i>
+disposition pointing in the same direction. If, for example, the mind of
+a naturalist has just been occupied about a certain class of bird, that
+is to say, if he has been dwelling on the <i>mental image</i> of this bird,
+he will recognize one at a distance more quickly than he would otherwise
+have done. Such a simple mental operation as the recognition of one of
+the less common flowers, say a particular orchid, will vary in duration
+according as we have or have not been recently forming an image of this
+flower. The obvious explanation of this is that the mental image of an
+object bears a very close resemblance to the corresponding percept,
+differing from it, indeed, in degree only, that is to say, through the
+fact that it involves no actual sensation. Here again we see illustrated
+a general psychological law, namely, that what the mind has recently
+done, it tends (within certain limits) to go on doing.</p>
+
+<p>It is to be noticed, further, that the perception of a single object or
+event is rarely an isolated act of the mind. We recognize and understand
+the things that<span class='pagenum'><a name="Page_30" id="Page_30">[Pg 30]</a></span> surround us through their relations one to another.
+Sometimes the adjacent circumstances and events suggest a definite
+expectation of the new impression. Thus, for example, the sound of a gun
+heard during a walk in the country is instantly interpreted by help of
+suggestions due to the previous appearance of the sportsman, and the act
+of raising the gun to his shoulder. It may be added that the verbal
+suggestions of others act very much like the suggestions of external
+circumstances. If I am told that a gun is going to be fired, my mind is
+prepared for it just as though I saw the sportsman.<a name="FNanchor_10_10" id="FNanchor_10_10"></a><a href="#Footnote_10_10" class="fnanchor">[10]</a></p>
+
+<p>More frequently the effect of such surrounding circumstances is to give
+an air of familiarity to the new impression, to shorten the interval in
+which the required interpretative image is forthcoming. Thus, when
+travelling in Italy, the visual impression answering to a ruined temple
+or a bareheaded friar is construed much more rapidly than it would be
+elsewhere, because of the attitude of mind due to the surrounding
+circumstances. In all such cases the process of preperception connected
+with a given impression is effected more or less completely by the
+suggestions of other and related impressions.</p>
+
+<p>It follows from all that has been just said that our minds are never in
+exactly the same state of readiness with respect to a particular process
+of perceptional interpretation. Sometimes the meaning of an impression
+flashes on us at once, and the stage of pre<span class='pagenum'><a name="Page_31" id="Page_31">[Pg 31]</a></span>perception becomes
+evanescent. At other times the same impression will fail for an
+appreciable interval to divulge its meaning. These differences are, no
+doubt, due in part to variations in the state of attention at the
+moment; but they depend as well on fluctuations in the degree of the
+mind's readiness to look at the impression in the required way.</p>
+
+<p>In order to complete this slight analysis of perception, we must look
+for a moment at its physical side, that is to say, at the nervous
+actions which are known or supposed with some degree of probability to
+accompany it.</p>
+
+<p>The production of the sensation is known to depend on a certain external
+process, namely, the action of some stimulus, as light, on the
+sense-organ, which stimulus has its point of departure in the object,
+such as it is conceived by physical science. The sensation arises when
+the nervous process is transmitted through the nerves to the conscious
+centre, often spoken of as the sensorium, the exact seat of which is
+still a matter of some debate.</p>
+
+<p>The intensification of the sensation by the reaction of attention is
+supposed to depend on some reinforcement of the nervous excitation in
+the sensory centre proceeding from the motor regions, which are
+hypothetically regarded as the centre of attention.<a name="FNanchor_11_11" id="FNanchor_11_11"></a><a href="#Footnote_11_11" class="fnanchor">[11]</a> The
+classification of the impression, again, is pretty certainly correlated
+with the physical fact that the central excitation calls into activity
+elements which have already been excited in the same way.</p>
+
+<p>The nervous counterpart of the final stage of per<span class='pagenum'><a name="Page_32" id="Page_32">[Pg 32]</a></span>ception, the synthesis
+of the sensation and the mental representation, is not clearly
+ascertained. A sensation clearly resembles a mental image in quality. It
+is most obviously marked off from the image by its greater vividness or
+intensity. Agreeably to this view, it is now held by a number of eminent
+physiologists and psychologists that the nervous process underlying a
+sensation occupies the same central region as that which underlies the
+corresponding image. According to this theory, the two processes differ
+in their degree of energy only, this difference being connected with the
+fact that the former involves, while the latter does not involve, the
+peripheral region of the nervous system. Accepting this view as on the
+whole well founded, I shall speak of an ideational, or rather an
+imaginational; and a sensational nervous process, and not of an
+ideational and a sensational centre.<a name="FNanchor_12_12" id="FNanchor_12_12"></a><a href="#Footnote_12_12" class="fnanchor">[12]</a></p>
+
+<p>The special force that belongs to the representative element in a
+percept, as compared with that of a pure "perceptional" image,<a name="FNanchor_13_13" id="FNanchor_13_13"></a><a href="#Footnote_13_13" class="fnanchor">[13]</a> is
+probably connected with the fact that, in the case of actual perception,
+the nervous process underlying the act of imaginative construction is
+organically united to the initial sensational process, of which indeed
+it may be regarded as a continuation.</p>
+
+<p>For the physical counterpart of the two stages in the<span class='pagenum'><a name="Page_33" id="Page_33">[Pg 33]</a></span> interpretative
+part of perception, distinguished as the passive stage of preperception,
+and the active stage of perception proper, we may, in the absence of
+certain knowledge, fall back on the hypothesis put forward by Dr. J.
+Hughlings Jackson, in the articles in <i>Brain</i> already referred to,
+namely, that the former answers to an action of the right hemisphere of
+the brain, the latter to a subsequent action of the left hemisphere. The
+expediting of the process of preperception in those cases where it has
+frequently been performed before, is clearly an illustration of the
+organic law that every function is improved by exercise. And the
+temporary disposition to perform the process due to recent imaginative
+activity, is explained at once on the physical side by the supposition
+that an actual perception and a perceptional image involve the activity
+of the same nervous tracts. For, assuming this to be the case, it
+follows, from a well-known organic law, that a recent excitation would
+leave a temporary disposition in these particular structures to resume
+that particular mode of activity.</p>
+
+<p>What has here been said about visual perception will apply, <i>mutatis
+mutandis</i>, to other kinds. Although the eye is the organ of perception
+<i>par excellence</i>, our other senses are also avenues by which we intuit
+and recognize objects. Thus touch, especially when it is finely
+developed as it is in the blind, gives an immediate knowledge of
+objects&mdash;a more immediate knowledge, indeed, of their fundamental
+properties than sight. What makes the eye so vastly superior to the
+organ of touch as an instrument of perception, is first of all the range
+of its action, taking in simultaneously<span class='pagenum'><a name="Page_34" id="Page_34">[Pg 34]</a></span> a large number of impressions
+from objects at a distance as well as near; and secondly, though this
+may seem paradoxical, the fact that it gives us so much indirectly, that
+is, by way of association and suggestion. This is the interesting side
+of visual perception, that, owing to the vast complex of distinguishable
+sensations of light and colour of various qualities and intensities,
+together with the muscular sensations attending the varying positions of
+the organ, the eye is able to recognize at any instant a whole external
+world with its fundamental properties and relations. The ear comes next
+to the eye in this respect, but only after a long interval, since its
+sensations (even in the case of musical combinations) do not
+simultaneously order themselves in an indefinitely large group of
+distinguishable elements, and since even the comparatively few
+sensations which it is capable of simultaneously receiving, being
+altogether passive&mdash;that is to say, having no muscular
+accompaniments&mdash;impart but little and vague information respecting the
+external order. It is plain, then, that in the study of illusion, where
+the indirectly known elements are the thing to be considered, the eye,
+and after this the ear, will mostly engage our attention.<a name="FNanchor_14_14" id="FNanchor_14_14"></a><a href="#Footnote_14_14" class="fnanchor">[14]</a></p>
+
+<p><span class='pagenum'><a name="Page_35" id="Page_35">[Pg 35]</a></span>So much it seemed needful to say about the mechanism of perception, in
+order to understand the slight disturbances of this mechanism that
+manifest themselves in sense-illusion. It may be added that our study of
+these illusions will help still further to elucidate the exact nature of
+perception. Normal mental life, as a whole, at once illustrates, and is
+illustrated by, abnormal. And while we need a rough provisional theory
+of accurate perception in order to explain illusory perception at all,
+the investigation of this latter cannot fail to verify and even render
+more complete the theory which it thus temporarily adopts.</p>
+
+
+<p class='center'><i>Illusions of Perception.</i></p>
+
+<p>With this brief psychological analysis of perception to help us, let us
+now pass to the consideration of the errors incident to the process,
+with a view to classify them according to their psychological nature and
+origin.</p>
+
+<p>And here there naturally arises the question, How shall we define an
+illusion of perception? When trying to fix the definition of illusion in
+general, I practically disposed of this question. Nevertheless, as the
+point appears to me to be of some importance, I shall reproduce and
+expand one or two of the considerations then brought forward.<span class='pagenum'><a name="Page_36" id="Page_36">[Pg 36]</a></span></p>
+
+<p>It is said by certain, philosophers that perception, as a whole, is an
+illusion, inasmuch as it involves the fiction of a real thing
+independent of mind, yet somehow present to it in the act of
+sense-perception. But this is a question for philosophy, not for
+science. Science, including psychology, assumes that in perception there
+is something real, without inquiring what it may consist of, or what its
+meaning may be. And though in the foregoing analysis of perception,
+viewed as a complex mental phenomenon or psychical process, I have
+argued that a percept gets its concrete filling up out of elements of
+conscious experience or sensations, I have been careful not to contend
+that the particular elements of feeling thus represented are the
+<i>object</i> of perception or the thing perceived. It may be that what we
+mean by a single object with its assemblage of qualities is much more
+than any number of such sensations; and it must be confessed that, on
+the face of it, it seems to be much more. And however this be, the
+question, What is meant by object; and is the common persuasion of the
+existence of such an entity in the act of perception accurate or
+illusory? must be handed over to philosophy.</p>
+
+<p>While in the following examination of sense-illusions we put out of
+sight what certain philosophers say about the illusoriness of perception
+as a whole, we shall also do well to leave out of account what physical
+science is sometimes supposed to tell us respecting a constant element
+of illusion in perception. The physicist, by reducing all external
+changes to "modes of motion," appears to leave no room in his
+world-mechanism for the secondary qualities of bodies, such<span class='pagenum'><a name="Page_37" id="Page_37">[Pg 37]</a></span> as light
+and heat, as popularly conceived. Yet, while allowing this, I think we
+may still regard the attribution of qualities like colour to objects as
+in the main correct and answering to a real fact. When a person says an
+object is red, he is understood by everybody as affirming something
+which is true or false, something therefore which either involves an
+external fact or is illusory. It would involve an external fact whenever
+the particular sensation which he receives is the result of a physical
+action (other vibrations of a certain order), which would produce a like
+sensation in anybody else in the same situation and endowed with the
+normal retinal sensibility. On the other hand, an illusory attribution
+of colour would imply that there is no corresponding physical agency at
+work in the case, but that the sensation is connected with exceptional
+individual conditions, as, for example, altered retinal sensibility.</p>
+
+<p>We are now, perhaps, in a position to frame a rough definition of an
+illusion of perception as popularly understood. A large number of such
+phenomena may be described as consisting in the formation of percepts or
+quasi-percepts in the minds of individuals under external circumstances
+which would not give rise to similar percepts in the case of other
+people.</p>
+
+<p>A little consideration, however, will show that this is not an adequate
+definition of what is ordinarily understood by an illusion of sense.
+There are special circumstances which are fitted to excite a momentary
+illusion in all minds. The optical illusions due to the reflection and
+refraction of light are not peculiar to the individual, but arise in all
+minds under precisely similar external conditions.<span class='pagenum'><a name="Page_38" id="Page_38">[Pg 38]</a></span></p>
+
+<p>It is plain that the illusoriness of a perception is in these cases
+determined in relation to the sense-impressions of other moments and
+situations, or to what are presumably better percepts than the present
+one. Sometimes this involves an appeal from one sense to another. Thus,
+there is the process of verification of sight by touch, for example, in
+the case of optical images, a mode of perception which, as we have seen,
+gives a more direct cognition of external quality. Conversely, there may
+occasionally be a reference from touch to sight, when it is a question
+of discriminating two points lying very close to one another. Finally,
+the same sense may correct itself, as when the illusion of the
+stereoscope is corrected by afterwards looking at the two separate
+pictures.</p>
+
+<p>We may thus roughly define an illusion of perception as consisting in
+the formation of a quasi-percept which is peculiar to an individual, or
+which is contradicted by another and presumably more accurate percept.
+Or, if we take the meaning of the word common to include both the
+universal as contrasted with the individual experience, and the
+permanent, constant, or average, as distinguished from the momentary and
+variable percept, we may still briefly describe an illusion of
+perception as a deviation from the common or collective experience.</p>
+
+
+<p class='center'><i>Sources of Sense-Illusion.</i></p>
+
+<p>Understanding sense-illusion in this way, let us glance back at the
+process of perception in its several stages or aspects, with the object
+of discovering what room occurs for illusion.<span class='pagenum'><a name="Page_39" id="Page_39">[Pg 39]</a></span></p>
+
+<p>It appears at first as if the preliminary stages&mdash;the reception,
+discrimination, and classification of an impression&mdash;would not offer the
+slightest opening for error. This part of the mechanism of perception
+seems to work so regularly and so smoothly that one can hardly conceive
+a fault in the process. Nevertheless, a little consideration will show
+that even here all does not go on with unerring precision.</p>
+
+<p>Let us suppose that the very first step is wanting&mdash;distinct attention
+to an impression. It is easy to see that this will favour illusion by
+leading to a confusion of the impression. Thus the timid man will more
+readily fall into the illusion of ghost-seeing than a cool-headed
+observant man, because he is less attentive to the actual impression of
+the moment. This inattention to the sense-impression will be found to be
+a great co-operating factor in the production of illusions.</p>
+
+<p>But if the sensation is properly attended to, can there be error through
+a misapprehension of what is actually in the mind at the moment? To say
+that there can may sound paradoxical, and yet in a sense this is
+demonstrable. I do not mean that there is an observant mind behind and
+distinct from the sensation, and failing to observe it accurately
+through a kind of mental short-sightedness. What I mean is that the
+usual psychical effect of the incoming nervous process may to some
+extent be counteracted by a powerful reaction of the centres. In the
+course of our study of illusions, we shall learn that it is possible for
+the quality of an impression, as, for example, of a sensation of colour,
+to be appreciably modified<span class='pagenum'><a name="Page_40" id="Page_40">[Pg 40]</a></span> when there is a strong tendency to regard it
+in one particular way.</p>
+
+<p>Postponing the consideration of these, we may say that certain illusions
+appear clearly to take their start from an error in the process of
+classifying or identifying a present impression. On the physical side,
+we may say that the first stages of the nervous process, the due
+excitation of the sensory centre in accordance with the form of the
+incoming stimulation and the central reaction involved in the
+recognition of the sensation, are incomplete. These are so limited and
+comparatively unimportant a class, that it will be well to dispose of
+them at once.</p>
+
+
+<p class='center'><i>Confusion of the Sense-Impression.</i></p>
+
+<p>The most interesting case of such an error is where the impression is
+unfamiliar and novel in character. I have already remarked that in the
+mental life of the adult perfectly new sensations never occur. At the
+same time, comparatively novel impressions sometimes arise. Parts of the
+sensitive surface of the body which rarely undergo stimulation are
+sometimes acted on, and at other times they receive partially new modes
+of stimulation. In such cases it is plain that the process of classing
+the sensation or recognizing it is not completed. It is found that
+whenever this happens there is a tendency to exaggerate the intensity of
+the sensation. The very fact of unfamiliarity seems to give to the
+sensation a certain exciting character. As something new and strange, it
+for the instant slightly agitates and discomposes the mind. Being unable
+to classify it with its like, we naturally magnify<span class='pagenum'><a name="Page_41" id="Page_41">[Pg 41]</a></span> its intensity, and
+so tend to ascribe it to a disproportionately large cause.</p>
+
+<p>For instance, a light bandage worn about the body at a part usually free
+from pressure is liable to be conceived as a weighty mass. The odd sense
+of a big cavity in the mouth, which we experience just after the loss of
+a tooth, is probably another illustration of this principle. And a third
+example may also be supplied from the recollection of the dentist's
+patient, namely, the absurd imagination which he tends to form as to
+what is actually going on in his mouth when a tooth is being bored by a
+modern rotating drill. It may be found that the same principle helps to
+account for the exaggerated importance which we attach to the
+impressions of our dreams.</p>
+
+<p>It is evident that all indistinct impressions are liable to be wrongly
+classed. Sensations answering to a given colour or form, are, when
+faint, easily confused with other sensations, and so an opening occurs
+for illusion. Thus, the impressions received from distant objects are
+frequently misinterpreted, and, as we shall see by-and-by, it is in this
+region of hazy impression that imagination is wont to play its most
+startling pranks.</p>
+
+<p>It is to be observed that the illusions arising from wrong
+classification will be more frequent in the case of those senses where
+discrimination is low. Thus, it is much easier in a general way to
+confuse two sensations of smell than two sensations of colour. Hence the
+great source of such errors is to be found in that mass of obscure
+sensation which is connected with the organic processes, as digestion,
+respiration, etc.,<span class='pagenum'><a name="Page_42" id="Page_42">[Pg 42]</a></span> together with those varying tactual and motor
+feelings, which result from what is called the subjective stimulation of
+the tactual nerves, and from changes in the position and condition of
+the muscles. Lying commonly in what is known as the sub-conscious region
+of mind, undiscriminated, vague, and ill-defined, these sensations, when
+they come to be specially attended to, readily get misapprehended, and
+so lead to illusion, both in waking life and in sleep. I shall have
+occasion to illustrate this later on.</p>
+
+<p>With these sensations, the result of stimulations coming from remote
+parts of the organism, may be classed the ocular impressions which we
+receive in indirect vision. When the eye is not fixed on an object, the
+impression, involving the activity of some-peripheral region of the
+retina, is comparatively indistinct. This will be much more the case
+when the object lies at a distance for which the eye is not at the time
+accommodated. And in these circumstances, when we happen to turn our
+attention to the impression, we easily misapprehend it, and so fall into
+illusion. Thus, it has been remarked by Sir David Brewster, in his
+<i>Letters on Natural Magic</i> (letter vii.), that when looking through a
+window at some object beyond, we easily suppose a fly on the window-pane
+to be a larger object, as a bird, at a greater distance.<a name="FNanchor_15_15" id="FNanchor_15_15"></a><a href="#Footnote_15_15" class="fnanchor">[15]</a></p><p><span class='pagenum'><a name="Page_43" id="Page_43">[Pg 43]</a></span></p>
+
+<p>While these cases of a confusion or a wrong classification of the
+sensation are pretty well made out, there are other illusions or
+quasi-illusions respecting which it is doubtful whether they should be
+brought under this head. For example, it was found by Weber, that when
+the legs of a pair of compasses are at a certain small distance apart
+they will be felt as two by some parts of the tactual surface of the
+body, but only as one by other parts. How are we to regard this
+discrepancy? Must we say that in the latter case there are two
+sensations, only that, being so similar, they are confused one with
+another? There seems some reason for so doing, in the fact that, by a
+repeated exercise of attention to the experiment, they may afterwards be
+recognized as two.</p>
+
+<p>We here come on the puzzling question, How much in the character of the
+sensation must be regarded as the necessary result of the particular
+mode of nervous stimulation at the moment, together with the laws of
+sensibility, and how much must be put down to the reaction of the mind
+in the shape of attention and discrimination? For our present purpose we
+may say that, whenever a deliberate effort of attention does not suffice
+to alter the character of a sensation, this may be pretty safely
+regarded as a net result of the nervous process, and any error arising
+may be referred to the later stages of the process of perception. Thus,
+for example, the taking of the two points of a pair of compasses for
+one, where the closest attention does not discover the error, is best
+regarded as arising, not from a confusion of the sense-impression, but
+from a wrong interpretation of a sensation, occasioned by an
+over<span class='pagenum'><a name="Page_44" id="Page_44">[Pg 44]</a></span>looking of the limits of local discriminative sensibility.</p>
+
+
+<p class='center'><i>Misinterpretation of the Sense-Impression.</i></p>
+
+<p>Enough has been said, perhaps, about those errors of perception which
+have their root in the initial process of sensation. We may now pass to
+the far more important class of illusions which are related to the later
+stages of perception, that is to say, the process of interpreting the
+sense-impression. Speaking generally, one may describe an illusion of
+perception as a misinterpretation. The wrong kind of interpretative
+mental image gets combined with the impression, or, if with Helmholtz we
+regard perception as a process of "unconscious inference," we may say
+that these illusions involve an unconscious fallacious conclusion. Or,
+looking at the physical side of the operation, it may be said that the
+central course taken by the nervous process does not correspond to the
+external relations of the moment.</p>
+
+<p>As soon as we inspect these illusions of interpretation, we see that
+they fall into two divisions, according as they are connected with the
+process of <i>suggestion</i>, that is to say, the formation of the
+interpretative image so far as determined by links of association with
+the actual impression, or with an independent process of <i>preperception</i>
+as explained above. Thus, for example, we fall into the illusion of
+hearing two voices when our shout is echoed back, just because the
+second auditory impression irresistibly calls up the image of a second
+shouter. On the other hand, a man experiences the illusion of seeing
+spectres of<span class='pagenum'><a name="Page_45" id="Page_45">[Pg 45]</a></span> familiar objects just after exciting his imagination over a
+ghost-story, because the mind is strongly predisposed to frame this kind
+of percept. The first class of illusions arises from without, the
+sense-impression being the starting-point, and the process of
+preperception being controlled by this. The second class arises rather
+from within, from an independent or spontaneous activity of the
+imagination. In the one case the mind is comparatively passive; in the
+other it is active, energetically reacting on the impression, and
+impatiently anticipating the result of the normal process of
+preperception. Hence I shall, for brevity's sake, commonly speak of them
+as Passive and Active Illusions.<a name="FNanchor_16_16" id="FNanchor_16_16"></a><a href="#Footnote_16_16" class="fnanchor">[16]</a></p>
+
+<p>I may, perhaps, illustrate these two classes of illusion by the simile
+of an interpreter poring over an old manuscript. The first would be due
+to some peculiarity in the document misleading his judgment, the second
+to some caprice or preconceived notion in the interpreter's mind.</p>
+
+<p>It is not difficult to define conjecturally the physiological conditions
+of these two large classes of illusion. On the physical side, an
+illusion of sense, like a just perception, is the result of a fusion of
+the nervous process answering to a sensation with a nervous process
+answering to a mental image. In the case of passive illusions, this
+fusion may be said to take place in consequence of some point of
+connection between the two. The existence of such a connection appears
+to be involved in the very fact of<span class='pagenum'><a name="Page_46" id="Page_46">[Pg 46]</a></span> suggestion, and may be said to be
+the organic result of frequent conjunctions of the two parts of the
+nervous operation in our past history. In the case of active illusions,
+however, which spring rather from the independent energy of a particular
+mode of the imagination, this point of organic connection is not the
+only or even the main thing. In many cases, as we shall see, there is
+only a faint shade of resemblance between the present impression and the
+mental image with which it is overlaid. The illusions dependent on
+vivid, expectation thus answer much less to an objective conjunction of
+past experiences than to a capricious subjective conjunction of mental
+images. Here, then, the fusion of nervous processes must have another
+cause. And it is not difficult to assign such a cause. The antecedent
+activity of imagination doubtless involves as its organic result a
+powerful temporary disposition in the nervous structures concerned to go
+on acting. In other words, they remain in a state of sub-excitation,
+which can be raised to full excitation by a slight additional force. The
+more powerful this disposition in the centres involved in the act of
+imagination, the less the additional force of external stimulus required
+to excite them to full activity.</p>
+
+<p>Considering the first division, passive illusions, a little further, we
+shall see that they may be broken up into two sub-classes, according to
+the causes of the errors. In a general way we assume that the impression
+always answers to some quality of the object which is perceived, and
+varies with this; that, for example, our sensation of colour invariably
+represents the quality of external colour which we attribute to the
+object.<span class='pagenum'><a name="Page_47" id="Page_47">[Pg 47]</a></span> Or, to express it physically, we assume that the external force
+acting on the sense-organ invariably produces the same effect, and that
+the effect always varies with the external cause. But this assumption,
+though true in the main, is not perfectly correct. It supposes that the
+organic conditions are constant, and that the organic process faithfully
+reflects the external operation. Neither of these suppositions is
+strictly true. Although in general we may abstract from the organism and
+view the relation between the external fact and the mental impression as
+direct, we cannot always do so.</p>
+
+<p>This being so, it is possible for errors of perception to arise through
+peculiarities of the nervous organization itself. Thus, as I have just
+observed, sensibility has its limits, and these limits are the
+starting-point in a certain class of widely shared or <i>common</i>
+illusions. An example of this variety is the taking of the two points of
+a pair of compasses for one by the hand, already referred to. Again, the
+condition of the nervous structures varies indefinitely, so that one and
+the same stimulus may, in the case of two individuals, or of the same
+individual at different times, produce widely unlike modes of sensation.
+Such variations are clearly fitted to lead to gross <i>individual</i> errors
+as to the external cause of the sensation. Of this sort is the illusory
+sense of temperature which we often experience through a special state
+of the organ employed.</p>
+
+<p>While there are these errors of interpretation due to some peculiarity
+of the organization, there are others which involve no such peculiarity,
+but arise<span class='pagenum'><a name="Page_48" id="Page_48">[Pg 48]</a></span> through the special character or exceptional conformation of
+the environment at the moment. Of this order are the illusions connected
+with the reflection of light and sound. We may, perhaps, distinguish the
+first sub-class as organically conditioned illusions, and the second as
+extra-organically determined illusions. It may be added that the latter
+are roughly describable as common illusions. They thus answer in a
+measure to the first variety of organically conditioned illusions,
+namely, those connected with the limits of sensibility. On the other
+hand, the active illusions, being essentially individual or subjective,
+may be said to correspond to the other variety of this class&mdash;those
+connected with variations of sensibility.</p>
+
+<p>Our scheme of sense-illusions is now complete. First of all, we shall
+take up the passive illusions, beginning with those which are
+conditioned by special circumstances in the organism. After that we
+shall illustrate those which depend on peculiar circumstances in the
+environment. And finally, we shall separately consider what I have
+called the active illusions of sense.</p>
+
+<p>It is to be observed that these illusions of perception properly so
+called, namely, the errors arising from a wrong interpretation of an
+impression, and, not from a confusion of one impression with another are
+chiefly illustrated in the region of the two higher senses, sight and
+hearing. For it is here, as we have seen, that the interpretative
+imagination has most work to do in evolving complete percepts of
+material, tangible objects, having certain relations in space, out of a
+limited and homogeneous class of<span class='pagenum'><a name="Page_49" id="Page_49">[Pg 49]</a></span> sensations, namely, those of light and
+colour, and of sound. As I have before observed, tactual perception, in
+so far as it is the recognition of an object of a certain size,
+hardness, and distance from our body, involves the least degree of
+interpretation, and so offers little room for error; it is only when
+tactual perception amounts to the <i>recognition</i> of an individual object,
+clothed with secondary as well as primary qualities, that an opening for
+palpable error occurs.</p>
+
+<p>With respect, however, to the first sub-class of these illusions,
+namely, those arising from organic peculiarities which give a twist, so
+to speak, to the sensation, no very marked contrast between the
+different senses presents itself. So that in illustrating this group we
+shall be pretty equally concerned with the various modes of perception
+connected with the different senses.</p>
+
+<p>It may be said once for all that in thus marking off from one another
+certain groups of illusion, I am not unmindful of the fact that these
+divisions answer to no very sharp natural distinctions. In fact, it will
+be found that one class gradually passes into the other, and that the
+different characteristics here separated often combine in a most
+perplexing way. All that is claimed for this classification is that it
+is a convenient mode of mapping out the subject.<span class='pagenum'><a name="Page_50" id="Page_50">[Pg 50]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER IV.</h2>
+
+<h4>ILLUSIONS OF PERCEPTION&mdash;<i>continued</i>.</h4>
+
+<p class='center'>A. <i>Passive Illusions</i> (<i>a</i>) <i>as determined by the Organism.</i></p>
+
+
+<p>In dealing with the illusions which are related to certain peculiarities
+in the nervous organism and the laws of sensibility, I shall commence
+with those which are connected with certain limits of sensibility.</p>
+
+
+<p class='center'><i>Limits of Sensibility.</i></p>
+
+<p>To begin with, it is known that the sensation does not always answer to
+the external stimulus in its degree or intensity. Thus, a certain amount
+of stimulation is necessary before any sensation arises. And this will,
+of course, be greater when there is little or no attention directed to
+the impression, that is to say, no co-operating central reaction. Thus
+it happens that slight stimuli go overlooked, and here illusion may have
+its starting-point. The most familiar example of such slight errors is
+that of movement. When we are looking at objects, our ocular muscles are
+apt to execute very slight movements which escape our notice. Hence we
+tend, under certain circumstances, to carry over the retinal result of
+the movement, that is to say, the im<span class='pagenum'><a name="Page_51" id="Page_51">[Pg 51]</a></span>pression produced by a shifting of
+the parts of the retinal image to new nervous elements, to the object
+itself, and so to transform a "subjective" into an "objective" movement.
+In a very interesting work on apparent or illusory movements, Professor
+Hoppe has fully investigated the facts of such slight movements, and
+endeavoured to specify their causes.<a name="FNanchor_17_17" id="FNanchor_17_17"></a><a href="#Footnote_17_17" class="fnanchor">[17]</a></p>
+
+<p>Again, even when the stimulus is sufficient to produce a conscious
+impression, the degree of the feeling may not represent the degree of
+the stimulus. To take a very inconspicuous case, it is found by Fechner
+that a given increase of force in the stimulus produces a less amount of
+difference in the resulting sensations when the original stimulus is a
+powerful one than when it is a feeble one. It follows from this, that
+differences in the degree of our sensations do not exactly correspond to
+objective differences. For example, we tend to magnify the differences
+of light among objects, all of which are feebly illuminated, that is to
+say, to see them much more removed from one another in point of
+brightness than when they are more strongly illuminated. Helmholtz
+relates that, owing to this tendency, he has occasionally caught
+himself, on a dark night, entertaining the illusion that<span class='pagenum'><a name="Page_52" id="Page_52">[Pg 52]</a></span> the
+comparatively bright objects visible in twilight were self-luminous.<a name="FNanchor_18_18" id="FNanchor_18_18"></a><a href="#Footnote_18_18" class="fnanchor">[18]</a></p>
+
+<p>Again, there are limits to the conscious separation of sensations which
+are received together, and this fact gives rise to illusion. In general,
+the number of distinguishable sensations answers to the number of
+external causes; but this is not always the case, and here we naturally
+fall into the error of mistaking the number of the stimuli. Reference
+has already been made to this fact in connection with the question
+whether consciousness can be mistaken as to the character of a present
+feeling.</p>
+
+<p>The case of confusing two impressions when the sensory fibres involved
+are very near one another, has already been alluded to. Both in touch
+and in sight we always take two or more points for one when they are
+only separated by an interval that falls below the limits of local
+discrimination. It seems to follow from this that our perception of the
+world as a continuum, made up of points perfectly continuous one with
+another may, for what we know, be illusory. Supposing the universe to
+consist of atoms separated by very fine intervals, then it is
+demonstrable that it would appear to our sensibility as a continuum,
+just as it does now.<a name="FNanchor_19_19" id="FNanchor_19_19"></a><a href="#Footnote_19_19" class="fnanchor">[19]</a></p>
+
+<p>Two or more simultaneous sensations are indis<span class='pagenum'><a name="Page_53" id="Page_53">[Pg 53]</a></span>tinguishable from one
+another, not only when they have nearly the same local origin, but under
+other circumstances. The blending of partial sensations of tone in a
+<i>klang</i>-sensation, and the coalescence in certain cases of the
+impressions received by way of the two retinas, are examples of this. It
+is not quite certain what determines this fusion of two simultaneous
+feelings. It may be said generally that it is favoured by similarity
+between the sensations;<a name="FNanchor_20_20" id="FNanchor_20_20"></a><a href="#Footnote_20_20" class="fnanchor">[20]</a> by a comparative feebleness of one of the
+feelings; by the fact of habitual concomitance, the two sensations
+occurring rarely, if ever, in isolation; and by the presence of a mental
+disposition to view them as answering to one external object. These
+considerations help us to explain the coalescence of the retinal
+impressions and its limits, the fusion of partial tones, and so on.<a name="FNanchor_21_21" id="FNanchor_21_21"></a><a href="#Footnote_21_21" class="fnanchor">[21]</a></p>
+
+<p>It is plain that this fusion of sensations, whatever its exact
+conditions may be, gives rise to error or wrong interpretation of the
+sense-impression. Thus, to take the points of two legs of a pair of
+compasses for one point is clearly an illusion of perception. Here is
+another and less familiar example. Very cold and smooth surfaces, as
+those of metal, often appear to be wet. I never feel sure, after wiping
+the blades of my skates, that they are perfectly dry, since they always<span class='pagenum'><a name="Page_54" id="Page_54">[Pg 54]</a></span>
+seem more or less damp to my hand. What is the reason of this? Helmholtz
+explains the phenomenon by saying that the feeling we call by the name
+of wetness is a compound sensation consisting of one of temperature and
+one of touch proper. These sensations occurring together so frequently,
+blend into one, and so we infer, according to the general instinctive
+tendency already noticed, that there is one specific quality answering
+to the feeling. And since the feeling is nearly always produced by
+surfaces moistened by cold liquid, we refer it to this circumstance, and
+speak of it as a feeling of wetness. Hence, when the particular
+conjunction of sensations arises apart from this external circumstance,
+we erroneously infer its presence.<a name="FNanchor_22_22" id="FNanchor_22_22"></a><a href="#Footnote_22_22" class="fnanchor">[22]</a></p>
+
+<p>The most interesting case of illusion connected with the fusion of
+simultaneous sensations, is that of single vision, or the deeply
+organized habit of combining the sensations of what are called the
+corresponding points of the two retinas. This coalescence of two
+sensations is so far erroneous since it makes us overlook the existence
+of two distinct external agencies acting on different parts of the
+sensitive surface of the body. And this is the more striking in the case
+of<span class='pagenum'><a name="Page_55" id="Page_55">[Pg 55]</a></span> looking at solid objects, since here it is demonstrable that the
+forces acting on the two retinas are not perfectly similar.
+Nevertheless, such a coalescence plainly answers to the fact that these
+external agencies usually arise in one and the same object, and this
+unity of the object is, of course, the all-important thing to be sure
+of.</p>
+
+<p>This habit may, however, beget palpable illusion in another way. In
+certain exceptional cases the coalescence does not take place, as when I
+look at a distant object and hold a pencil just before my eyes.<a name="FNanchor_23_23" id="FNanchor_23_23"></a><a href="#Footnote_23_23" class="fnanchor">[23]</a> And
+in this case the organized tendency to take one visual impression for
+one object asserts its force, and I tend to fall into the illusion of
+seeing two separate pencils. If I do not wholly lapse into the error, it
+is because my experience has made me vaguely aware that double images
+under these circumstances answer to one object, and that if there were
+really two pencils present I should have four visual impressions.</p>
+
+<p>Once more, it is a law of sensory stimulation that an impression
+persists for an appreciable time after the cessation of the action of
+the stimulus. This "after sensation" will clearly lead to illusion, in
+so far as we tend to think of the stimulus as still at work. It forms,
+indeed, as will be seen by-and-by, the simplest and lowest stage of
+hallucination. Sometimes this becomes the first stage of a palpable
+error. After listening to a child crying for some time the ear<span class='pagenum'><a name="Page_56" id="Page_56">[Pg 56]</a></span> easily
+deceives itself into supposing that the noise is continued when it has
+actually ceased. Again, after taking a bandage from a finger, the
+tingling and other sensations due to the pressure sometimes persist for
+a good time, in which case they easily give rise to an illusion that the
+finger is still bound.</p>
+
+<p>It follows from this fact of the reverberation of the nervous structures
+after the removal of a stimulus, that whenever two discontinuous
+stimulations follow one another rapidly enough, they will appear
+continuous. This fact is a fruitful source of optical illusion. The
+appearance of a blending of the stripes of colours on a rotating disc or
+top, of the formation of a ring of light by swinging round a piece of
+burning wood, and the illusion of the toy known as the thaumatrope, or
+wheel of life, all depend on this persistence of retinal impression.
+Many of the startling effects of sleight of hand are undoubtedly due in
+part to this principle. If two successive actions or sets of
+circumstances to which the attention of the spectator is specially
+directed follow one another by a very narrow interval of time, they
+easily appear continuous, so that there seems absolutely no time for the
+introduction of an intermediate step.<a name="FNanchor_24_24" id="FNanchor_24_24"></a><a href="#Footnote_24_24" class="fnanchor">[24]</a></p>
+
+<p>There is another limit to sensibility which is in a manner the opposite
+to the one just named. It is a<span class='pagenum'><a name="Page_57" id="Page_57">[Pg 57]</a></span> law of nervous stimulation that a
+continued activity of any structure results in less and less psychic
+result, and that when a stimulus is always at work it ceases in time to
+have any appreciable effect. The common illustration of this law is
+drawn from the region of sound. A constant noise, as of a mill, ceases
+to produce any conscious sensation. This fact, it is plain, may easily
+become the commencement of an illusion. Not only may we mistake a
+measure of noise for perfect silence,<a name="FNanchor_25_25" id="FNanchor_25_25"></a><a href="#Footnote_25_25" class="fnanchor">[25]</a> we may misconceive the real
+nature of external circumstances by overlooking some continuous
+impression.</p>
+
+<p>Curious illustrations of this effect are found in optical illusions,
+namely, the errors we make respecting the movement of stationary objects
+after continued movement of the eyes. When, for example, in a railway
+carriage we have for some time been following the (apparent) movement of
+objects, as trees, etc., and turn our eyes to an apparently stationary
+object, as the carpet of the compartment, this seems to move in the
+contrary direction to that of the trees. Helmholtz's explanation of this
+illusion is that when we suppose that we are fixing our eye on the
+carpet we are really continuing to move it over the surface by reason of
+the organic tendency, already spoken of, to go on doing anything that
+has been done. But since we are unaware of this prolonged series of
+ocular movements, the muscular feelings having become faint, we take the
+impression produced by the sliding of the<span class='pagenum'><a name="Page_58" id="Page_58">[Pg 58]</a></span> picture over the retina to be
+the result of a movement of the object.<a name="FNanchor_26_26" id="FNanchor_26_26"></a><a href="#Footnote_26_26" class="fnanchor">[26]</a></p>
+
+<p>Another limit to our sensibility, which needs to be just touched on
+here, is known by the name of the specific energy of the nerves. One and
+the same nerve-fibre always reacts in a precisely similar way, whatever
+the nature of the stimulus. Thus, when the optic nerve is stimulated in
+any manner, whether by light, mechanical pressure, or an electric
+current, the same effect, a sensation of light, follows.<a name="FNanchor_27_27" id="FNanchor_27_27"></a><a href="#Footnote_27_27" class="fnanchor">[27]</a> In a usual
+way, a given class of nerve-fibre is only stimulated by one kind of
+stimulus. Thus, the retina, in ordinary circumstances, is stimulated by
+light. Owing to this fact, there has arisen a deeply organized habit of
+translating the impression in one particular way. Thus, I instinctively
+regard a sensation received by means of the optic nerve as one caused by
+light.</p>
+
+<p>Accordingly, whenever circumstances arise in which a like sensation is
+produced by another kind of stimulus, we fall into illusion. The
+phosphenes, or circles of light which are seen when the hinder part of
+the eye<span class='pagenum'><a name="Page_59" id="Page_59">[Pg 59]</a></span>ball is pressed, may be said to be illusory in so far as we
+speak of them as perceptions of light, thus referring them to the
+external physical agency which usually causes them. The same remark
+applies to those "subjective sensations," as they are called, which are
+known to have as their physical cause subjective stimuli, consisting, in
+the case of sight, in varying conditions of the peripheral organ, as
+increased blood-pressure. Strictly speaking, such simple feelings as
+these appear to be, involve an ingredient of false perception: in saying
+that we <i>perceive</i> light at all, we go beyond the pure sensation,
+interpreting this wrongly.</p>
+
+<p>Very closely connected with this limitation of our sensibility is
+another which refers to the consciousness of the local seat, or origin
+of the impression. This has so far its basis in the sensation itself as
+it is well known that (within the limits of local discrimination,
+referred to above) sensations have a particular "local" colour, which
+varies in the case of each of the nervous fibres by the stimulation of
+which they arise.<a name="FNanchor_28_28" id="FNanchor_28_28"></a><a href="#Footnote_28_28" class="fnanchor">[28]</a> But though this much is known through a difference
+in the sensibility, nothing more is known. Nothing can certainly be
+ascertained by a mere inspection of the sensation as to the distance the
+nervous process has travelled, whether from the peripheral termination
+of the fibre or from some intermediate point.</p>
+
+<p>In a general way, we refer our sensations to the peripheral endings of
+the nerves concerned, according to what physiologists have called "the
+law of eccen<span class='pagenum'><a name="Page_60" id="Page_60">[Pg 60]</a></span>tricity." Thus I am said to feel the pain caused by a
+bruise in the foot in the member itself. This applies also to some of
+the sensations of the special senses. Thus, impressions of taste are
+clearly localized in the corresponding peripheral terminations.</p>
+
+<p>With respect to the sense of smell, and still more to those of hearing
+and sight, where the impression is usually caused by an object at a
+distance from the peripheral organ, our attention to this external cause
+leads us to overlook in part the "bodily seat" of the sensation. Yet
+even here we are dimly aware that the sensation is received by way of a
+particular part of the sensitive surface, that is to say, by a
+particular sense-organ. Thus, though referring an odour to a distant
+flower, we perceive that the sensation of odour has its bodily origin in
+the nose. And even in the case of hearing and sight, we vaguely refer
+the impressions, as such, to the appropriate sense-organ. There is,
+indeed, in these cases a double local reference, a faint one to the
+peripheral organ which is acted on, and a more distinct one to the
+object or the force in the environment which acts on this.</p>
+
+<p>Now, it may be said that the act of localization is in itself distinctly
+illusory, since it is known that the sensation first arises in
+connection with the excitation of the sensory <i>centre</i>, and not of the
+peripheral fibre.<a name="FNanchor_29_29" id="FNanchor_29_29"></a><a href="#Footnote_29_29" class="fnanchor">[29]</a></p><p><span class='pagenum'><a name="Page_61" id="Page_61">[Pg 61]</a></span> Yet it must at least be allowed that this
+localization of sensation answers to the important fact that, under
+usual circumstances, the agency producing the sensation is applied at
+this particular point of the organism, the knowledge of which point is
+supposed by modern psychologists to have been very slowly learnt by the
+individual and the race, through countless experiments with the moving
+organ of touch, assisted by the eye.</p>
+
+<p>Similarly, the reference of the impression, in the case of hearing and
+sight, to an object in the environment, though, as we have seen, from
+one point of view illusory, clearly answers to a fact of our habitual
+experience; for in an immense preponderance of cases at least a visual
+or auditory impression does arise through the action on the sense-organ
+of a force (ether or air waves) proceeding from a distant object.</p>
+
+<p>In some circumstances, however, even this element of practical truth
+disappears, and the localization of the impression, both within and
+without the organism, becomes altogether illusory. This result is
+involved in the illusions, already spoken of, which arise from the
+instinctive tendency to refer sensations to the ordinary kind of
+stimulus. Thus, when a feeling resulting from a disturbance in the optic
+nerve is interpreted as one of external light vaguely felt to be acting
+on the eye, or one resulting from some action set up in the auditory
+fibre as a sensation of external sound vaguely felt to be entering the
+ear, we see that the error of localization is a consequence of the other
+error already characterized.</p>
+
+<p>As I have already observed, an excitation of a nerve at any other point
+than the peripheral termi<span class='pagenum'><a name="Page_62" id="Page_62">[Pg 62]</a></span>nation, occurs but rarely in normal life. One
+familiar instance is the stimulation of the nerve running to the hand
+and fingers, by a sharp blow on the elbow over which it passes. As
+everybody knows, this gives rise to a sense of pain at the <i>extremities</i>
+of the nerve. The most common illustration of such errors of
+localization is found in subjective sensations, such as the impression
+we sometimes have of something creeping over the skin, of a disagreeable
+taste in the mouth, of luminous spots floating across the field of
+vision, and so on. The exact physiological seat of these is often a
+matter of conjecture only; yet it may safely be said that in many
+instances the nervous excitation originates at some point considerably
+short of its peripheral extremity: in which case there occurs the
+illusion of referring the impressions to the peripheral sense-organ, and
+to an external force acting on this.</p>
+
+<p>The most striking instances of these errors of localization are found in
+abnormal circumstances. It is well known that a man who has lost a leg
+refers all sensations arising from a stimulation of the truncated fibres
+to his lost foot, and in some cases has even to convince himself of the
+non-existence of his lost member by sight or touch. Patients often
+describe these experiences in very odd language. "If," says one of Dr.
+Weir Mitchell's patients, "I should say I am more sure of the leg which
+ain't than the one which air, I guess I should be about correct."<a name="FNanchor_30_30" id="FNanchor_30_30"></a><a href="#Footnote_30_30" class="fnanchor">[30]</a></p><p><span class='pagenum'><a name="Page_63" id="Page_63">[Pg 63]</a></span></p>
+
+<p>There is good reason for supposing that this source of error plays a
+prominent part in the illusions of the insane. Diseased centres may be
+accompanied by disordered peripheral structures, and so subjective
+sensation may frequently be the starting-point of the wildest illusions.
+Thus, a patient's horror of poison may have its first origin in some
+subjective gustatory sensation. Similarly, subjective tactual sensations
+may give rise to gross illusions, as when a patient "feels" his body
+attacked by foul and destructive creatures.</p>
+
+<p>It may be well to remark that this mistaken interpretation of the seat
+or origin of subjective sensation is closely related to hallucination.
+In so far as the error involves the ascription of the sensation to a
+force external to the sense-organ, this part of the mental process must,
+when there is no such force present, be viewed as hallucinatory. Thus,
+the feeling of something creeping over the skin is an hallucination in
+the sense that it implies the idea of an object external to the skin.
+Similarly, the projection of an ocular impression due to retinal
+disturbance into the external field of vision, may rightly be named an
+hallucination. But the case is not always so clear as this. Thus, for
+example, when a gustatory sensation is the result of an altered
+condition of the saliva, it may be said that the error is as much an
+illusion as an hallucination.<a name="FNanchor_31_31" id="FNanchor_31_31"></a><a href="#Footnote_31_31" class="fnanchor">[31]</a></p>
+
+<p>In a wide sense, again, all errors connected with<span class='pagenum'><a name="Page_64" id="Page_64">[Pg 64]</a></span> those subjective
+sensations which arise from a stimulation of the peripheral regions of
+the nerve may be called illusions rather than hallucinations. Or, if
+they must be called hallucinations, they may be distinguished as
+"peripheral" from those "central" hallucinations which arise through an
+internal automatic excitation of the sensory centre. It is plain from
+this that the region of subjective sensation is an ambiguous region,
+where illusion and hallucination mix and become confused. To this point
+I shall have occasion to return by-and-by.</p>
+
+<p>I have now probably said enough respecting the illusions that arise
+through the fact of there being fixed limits to our sensibility. The
+<i>rationale</i> of these illusions is that whenever the limit is reached, we
+tend to ignore it and to interpret the impression in the customary way.</p>
+
+
+<p class='center'><i>Variations of Sensibility.</i></p>
+
+<p>We will now pass to a number of illusions which depend on something
+variable in the condition of our sensibility, or some more or less
+exceptional organic circumstance. These variations may be momentary and
+transient or comparatively permanent. The illusion arises in each case
+from our ignoring the variation, and treating a given sensation under
+all circumstances as answering to one objective cause.</p>
+
+<p>First of all, the variation of organic state may affect our mental
+representation of the strength of the stimulus or external cause. Here
+the fluctuation may be a temporary or a permanent one. The first case is
+illustrated in the familiar example of taking a room<span class='pagenum'><a name="Page_65" id="Page_65">[Pg 65]</a></span> to be brighter
+than it is when emerging from a dark one. Another striking example is
+that of our sense of the temperature of objects, which is known to be
+strictly relative to a previous sensation, or more correctly to the
+momentary condition of the organ. Yet, though every intelligent person
+knows this, the deeply rooted habit of making sensation the measure of
+objective quality asserts its sway, and frequently leads us into
+illusion. The well-known experiment of first plunging one hand in cold
+water, the other in hot, and then dipping them both in tepid, is a
+startling example of this organized tendency. For here we are strongly
+disposed to accept the palpable contradiction that the same water is at
+once warm and cool.</p>
+
+<p>Far more important than these temporary fluctuations of sensibility are
+the permanent alterations. Excessive fatigue, want of proper nutrition,
+and certain poisons are well known to be causes of such changes. They
+appear most commonly under two forms, exalted sensibility, or
+hyper&aelig;sthesia, and depressed sensibility, or an&aelig;sthesia. In these
+conditions flagrant errors are made as to the real magnitude of the
+causes of the sensations. These variations may occur in normal life to
+some extent. In fairly good health we experience at times strange
+exaltations of tactual sensibility, so that a very slight stimulus, such
+as the contact of the bed-clothes, becomes greatly exaggerated.</p>
+
+<p>In diseased states of the nervous system these variations of sensibility
+become much more striking. The patient who has hyper&aelig;sthesia fears to
+touch a perfectly smooth surface, or he takes a knock at the door to be
+a clap of thunder. The hypochondriac may,<span class='pagenum'><a name="Page_66" id="Page_66">[Pg 66]</a></span> through an increase of
+organic sensibility, translate organic sensations as the effect of some
+living creature gnawing at his vitals. Again, states of an&aelig;sthesia lead
+to odd illusions among the insane. The common supposition that the body
+is dead, or made of wood or of glass, is clearly referable in part to
+lowered sensibility of the organism.<a name="FNanchor_32_32" id="FNanchor_32_32"></a><a href="#Footnote_32_32" class="fnanchor">[32]</a></p>
+
+<p>It is worth adding, perhaps, that these variations in sensibility give
+rise not only to sensory but also to motor illusions. To take a homely
+instance, the last miles of a long walk seem much longer than the first,
+not only because the sense of fatigue leading us to dwell on the
+transition of time tends to magnify the apparent duration, but because
+the fatigued muscles and connected nerves yield a new set of sensations
+which constitute an exaggerated standard of measurement. A number of
+optical illusions illustrate the same thing. Our visual sense of
+direction is determined in part by the feelings accompanying the action
+of the ocular muscles, and so is closely connected with the perception
+of movement, which has already been touched on. If an ocular muscle is
+partially paralyzed it takes a much greater "effort" to effect a given
+extent of movement than when the muscle is sound. Hence any movement
+performed by the eye seems exaggerated. Hence, too, in this condition
+objects are seen in a wrong direction; for the patient reasons that they
+are where they would seem to be if he had executed a wider movement than
+he really has. This may easily be proved by asking him to try to seize<span class='pagenum'><a name="Page_67" id="Page_67">[Pg 67]</a></span>
+the object with, his hand. The effect is exaggerated when complete
+paralysis sets in, and no actual movement occurs in obedience to the
+impulse from within.<a name="FNanchor_33_33" id="FNanchor_33_33"></a><a href="#Footnote_33_33" class="fnanchor">[33]</a></p>
+
+<p>Variations in the condition of the nerve affect not only the degree, but
+also the quality of the sensation, and this fact gives rise to a new
+kind of illusion. The curious phenomena of colour-contrast illustrate
+momentary alterations of sensibility. When, after looking at a green
+colour for a time, I turn my eye to a grey surface and see this of the
+complementary rose-red hue, the effect is supposed to be due to a
+temporary fatigue of the retina in relation to those ingredients of the
+total light in the second case which answer to the partial light in the
+first (the green rays).<a name="FNanchor_34_34" id="FNanchor_34_34"></a><a href="#Footnote_34_34" class="fnanchor">[34]</a></p>
+
+<p>These momentary modifications of sensibility are<span class='pagenum'><a name="Page_68" id="Page_68">[Pg 68]</a></span> of no practical
+significance, being almost instantly corrected. Other modifications are
+more permanent. It was found by Himly that when the retina is
+overexcitable every stimulus is raised in the spectrum scale of colours.
+Thus, violet becomes red. An exactly opposite effect is observed when
+the retina is torpid.<a name="FNanchor_35_35" id="FNanchor_35_35"></a><a href="#Footnote_35_35" class="fnanchor">[35]</a> Certain poisons are known to affect the
+quality of the colour-impression. Thus, santonin, when taken in any
+quantity, makes all colourless objects look yellow. Severe pathological
+disturbances are known to involve, in addition to hyper&aelig;sthesia and
+an&aelig;sthesia, what, has been called par&aelig;sthesia, that is to say, that
+condition in which the quality of sensation is greatly changed. Thus,
+for example, to one in this state all food appears to have a metallic
+taste, and so on.</p>
+
+<p>If we now glance back at the various groups of illusions just
+illustrated, we find that they all have this feature in common: they
+depend on the general mental law that when we have to do with the
+unfrequent, the unimportant, and therefore unattended to, and the
+exceptional, we employ the ordinary, the familiar, and the well-known as
+our standard. Thus, whether we are dealing with sensations that fall
+below the ordinary limits of our mental experience, or with those which
+arise in some exceptional state of the organism, we carry the habits
+formed in the much wider region of average every-day perception with us.
+In a word, illusion in these cases always arises through what may,
+figuratively at least, be described as the application of a rule, valid
+for the majority of cases, to an exceptional case.<span class='pagenum'><a name="Page_69" id="Page_69">[Pg 69]</a></span></p>
+
+<p>In the varieties of illusion just considered, the circumstance that
+gives the peculiarity to the case thus wrongly interpreted has been
+referred to the organism. In the illusions to which we now pass, it will
+be referred to the environment. At the same time, it is plain that there
+is no very sharp distinction between the two classes. Thus, the visual
+illusion produced by pressing the eyeball might be regarded not only as
+the result of the organic law of the "specific energy" of the nerves,
+but, with almost equal appropriateness, as the consequence of an
+exceptional state of things in the environment, namely, the pressure of
+a body on the retina. As I have already observed, the classification
+here adopted is to be viewed simply as a rough expedient for securing
+something like a systematic review of the phenomena.<span class='pagenum'><a name="Page_70" id="Page_70">[Pg 70]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER V.</h2>
+
+<h4>ILLUSIONS OF PERCEPTION&mdash;<i>continued</i>.</h4>
+
+<p class='center'>A. <i>Passive Illusions (b) as determined by the<br />Environment.</i></p>
+
+
+<p>In the following groups of illusion we may look away from nervous
+processes and organic disturbances, regarding the effect of any external
+stimulus as characteristic, that is, as clearly marked off from the
+effects of other stimuli, and as constant for the same stimulus. The
+source of the illusion will be looked for in something exceptional in
+the external circumstances, whereby one object or condition of an object
+imitates the effect of another object or condition, to which, owing to a
+large preponderance of experience, we at once refer it.</p>
+
+
+<p class='center'><i>Exceptional Relation of Stimulus to Organ.</i></p>
+
+<p>A transition from the preceding to the following class of illusions is
+to be met with in those errors which arise from a very exceptional
+relation between the stimulus and the organ of sense. Such a state of
+things is naturally interpreted by help of more common and familiar
+relations, and so error arises.<span class='pagenum'><a name="Page_71" id="Page_71">[Pg 71]</a></span></p>
+
+<p>For example, we may grossly misinterpret the intensity of a stimulus
+under certain circumstances. Thus, when a man crunches a biscuit, he has
+an uncomfortable feeling that the noise as of all the structures of his
+head being violently smashed is the same to other ears, and he may even
+act on his illusory perception, by keeping at a respectful distance from
+all observers. And even though he be a physiologist, and knows that the
+force of sensation in this case is due to the propagation of vibrations
+to the auditory centre by other channels than the usual one of the ear,
+the deeply organized impulse to measure the strength of an external
+stimulus by the intensity of the sensation asserts its force.</p>
+
+<p>Again, if we turn to the process of perceptional construction properly
+so called, the reference of the sensation to a material object lying in
+a certain direction, etc., we find a similar transitional form of
+illusion. The most interesting case of this in visual perception is that
+of a disturbance or displacement of the organ by external force. For
+example, an illusory sense of direction arises by the simple action of
+closing one eye, say the left, and pressing the other eyeball with one
+of the fingers a little outwards, that is to the right. The result of
+this movement is, of course, to transfer the retinal picture to new
+nervous elements further to the right. And since, in this instance, the
+displacement is not produced in the ordinary way by the activity of the
+ocular muscle making itself known by certain feelings of movement, it is
+disregarded altogether, and the direction of the objects is judged as
+though the eye were stationary.<span class='pagenum'><a name="Page_72" id="Page_72">[Pg 72]</a></span></p>
+
+<p>A somewhat similar illusion as to direction occurs in auditory
+perception. The sense of direction by the ear is known to be due in part
+to the action of the auricle, or projecting part of the ear. This
+collects the air-waves, and so adds to the intensity of the sounds,
+especially those coming from in front, and thus assists in the
+estimation of direction. This being so, if an artificial auricle is
+placed in front of the ears; if, for example, the two hands are each
+bent into a sort of auricle, and placed in front of the ears, the back
+of the hand being in front, the sense of direction (as well as of
+distance) is confused. Thus, sounds really travelling from a point in
+front of the head will appear to come from behind it.</p>
+
+<p>Again, the perception of the unity of an object is liable to be
+falsified by the introduction of exceptional circumstances into the
+sense-organ. This is illustrated in the well-known experiment of
+crossing two fingers, say the third and fourth, and placing a marble or
+other small round object between them. Under ordinary circumstances, the
+two lateral surfaces (that is, the outer surfaces of the two fingers)
+now pressed by the marble, can only be acted on simultaneously by <i>two</i>
+objects having convex surfaces. Consequently, we cannot help feeling the
+presence of two objects in this exceptional instance. The illusion is
+analogous to that of the stereoscope, to be spoken of presently.</p>
+
+
+<p class='center'><i>Exceptional External Arrangements.</i></p>
+
+<p>Passing now to those cases where the exceptional circumstance is
+altogether exterior to the organ, we find a familiar example in the
+illusions connected with<span class='pagenum'><a name="Page_73" id="Page_73">[Pg 73]</a></span> the action of well-known physical forces, as
+the refraction of light, and the reflection of light and sound. A stick
+half-immersed in water always <i>looks</i> broken, however well we may know
+that the appearance is due to the bending of the rays of light.
+Similarly, an echo always sounds as though it came from some object in
+the direction in which the air-waves finally travel to the ear, though
+we are perfectly sure that these undulations have taken a circuitous
+course. It is hardly necessary to remind the reader that the deeply
+organized tendency to mistake the direction of the visible or audible
+object in these cases has from remote ages been made use of as a means
+of popular delusion. Thus, we are told by Sir D. Brewster, in his
+entertaining <i>Letters on Natural Magic</i> (letter iv.), that the concave
+mirror was probably used as the instrument for bringing the gods before
+the people. The throwing of the images formed by such mirrors upon smoke
+or against fire, so as to make them more distinct, seems to have been a
+favourite device in the ancient art of necromancy.</p>
+
+<p>Closely connected with these illusions of direction with respect to
+resting objects, are those into which we are apt to fall respecting the
+movements of objects. What looks like the movement of something across
+the field of vision is made known to us either by the feeling of the
+ocular muscles, if the eye follows the object, or through the sequence
+of locally distinct retinal impressions, if the eye is stationary. Now,
+either of these effects may result, not only from the actual movement of
+the object in a particular direction, but from our own movement in an
+opposite<span class='pagenum'><a name="Page_74" id="Page_74">[Pg 74]</a></span> direction; or, again, from our both moving in the first
+direction, the object more rapidly than ourselves; or, finally, from our
+both moving in an opposite direction to this, ourselves more rapidly
+than the object. There is thus always a variety of conceivable
+explanations, and the action of past experience and association shows
+itself very plainly in the determination of the direction of
+interpretation. Thus, it is our instinctive tendency to take apparent
+movement for real movement, except when the fact of our own movement is
+clearly present to consciousness, as when we are walking, or when we are
+sitting behind a horse whose movement we see. And so when the sense of
+our own movement becomes indistinct, as in a railway carriage, we
+naturally drift into the illusion that objects, such as trees, telegraph
+posts, and so on, are moving, when they are perfectly still. Under the
+same circumstances, we are apt to suppose that a train which is just
+shooting ahead of us is moving slowly.</p>
+
+<p>Similar uncertainties arise with respect to the relative movement of two
+objects, the eye being supposed to be fixed in space. When two objects
+seem to pass one another, it may be that they are both moving in
+contrary directions, or that one only is moving, or finally, that both
+are moving in the same direction, the one faster than the other.
+Experience and habit here again suggest the interpretation which is most
+easy, and not unfrequently produce illusion. Thus, when we watch clouds
+scudding over the face of the moon, the latter seems moving rather than
+the former, and the illusion only disappears when we fix the eye on the
+moon and recognize that it is really<span class='pagenum'><a name="Page_75" id="Page_75">[Pg 75]</a></span> stationary. The probable reason of
+this is, as Wundt suggests, that experience has made it far easier for
+us to think of small objects like the moon moving rapidly, than of large
+masses like the clouds.<a name="FNanchor_36_36" id="FNanchor_36_36"></a><a href="#Footnote_36_36" class="fnanchor">[36]</a></p>
+
+<p>The perception of distance, still more than that of direction, is liable
+to be illusory. Indeed, the visual recognition of distance, together
+with that of solidity, has been the great region for the study of "the
+deceptions of the senses." Without treating the subject fully here, I
+shall try to describe briefly the nature and source of these
+illusions.<a name="FNanchor_37_37" id="FNanchor_37_37"></a><a href="#Footnote_37_37" class="fnanchor">[37]</a></p>
+
+<p>Confining ourselves first of all to near objects, we know that the
+smaller differences of distance in these cases are, if the eyes are at
+rest, perceived by means of the dissimilar pictures projected on the two
+retinas; or if they move, by this means, together with the muscular
+feelings that accompany different degrees of convergence of the two
+eyes. This was demonstrated by the famous experiments of Wheatstone.
+Thus, by means of the now familiar stereoscope, he was able to produce a
+perfect illusion of relief. The stereoscope may be<span class='pagenum'><a name="Page_76" id="Page_76">[Pg 76]</a></span> said to introduce an
+exceptional state of things into the spectator's environment. It
+imitates, by means of two flat drawings, the dissimilar retinal pictures
+projected by a single solid receding object, and the lenses through
+which the eyes look are so constructed as to compel them to converge as
+though looking on a single object. And so powerful is the tendency to
+interpret this impression as one of solidity, that even though we are
+aware of the presence of the stereoscopic apparatus, we cannot help
+seeing the two drawings as a single solid object.</p>
+
+<p>In the case of more remote objects, there is no dissimilarity of the
+retinal pictures or feelings of convergence to assist the eye in
+determining distance. Here its judgment, which now becomes more of a
+process of <i>conscious</i> inference, is determined by a number of
+circumstances which, through experience and association, have become the
+signs of differences of depth in space. Among these are the degree of
+indistinctness of the impression, the apparent or retinal magnitude (if
+the object is a familiar one), the relations of linear perspective, as
+the interruption of the outline of far objects by that of near objects,
+and so on. In a process so complicated there is clearly ample room for
+error, and wrong estimates of distance whenever unusual circumstances
+are present are familiar to all. Thus, the inexperienced English
+tourist, when in the clear atmosphere of Switzerland, where the
+impressions from distant objects are more distinct than at home,
+naturally falls into the illusion that the mountains are much nearer
+than they are, and so fails to realize their true altitude.<span class='pagenum'><a name="Page_77" id="Page_77">[Pg 77]</a></span></p>
+
+<p class='center'><i>Illusions of Art.</i></p>
+
+<p>The imitation of solidity and depth by art is a curious and interesting
+illustration of the mode of production of illusion. Here we are not, of
+course, concerned with the question how far illusion is desirable in
+art, but only with its capabilities of illusory presentment; which
+capabilities, it may be added, have been fully illustrated in the
+history of art. The full treatment of this subject would form a chapter
+in itself; here I can only touch on its main features.</p>
+
+<p>Pictorial art working on a flat surface cannot, it is plain, imitate the
+stereoscope, and produce a perfect sense of solidity. Yet it manages to
+produce a pretty strong illusion. It illustrates in a striking manner
+the ease with which the eye conceives relations of depth or relief and
+solidity. If, for example, on a carpet, wall-paper, or dress, bright
+lines are laid on a dark colour as ground, we easily imagine that they
+are advancing. The reason of this seems to be that in our daily
+experience advancing surfaces catch and reflect the light, whereas
+retiring surfaces are in shadow.<a name="FNanchor_38_38" id="FNanchor_38_38"></a><a href="#Footnote_38_38" class="fnanchor">[38]</a></p>
+
+<p>The same principle is illustrated in one of the means used by the artist
+to produce a strong sense of relief, namely, the cast shadow. A circle
+drawn with chalk with a powerful cast shadow on one side<span class='pagenum'><a name="Page_78" id="Page_78">[Pg 78]</a></span> will, without
+any shading or modelling of the form, appear to stand out from the
+paper, thus:</p>
+
+<div class="figcenter">
+             <img   src="images/img088-1.jpg"
+             alt="FIG. 1." /><br />
+        FIG. 1.
+    </div>
+
+
+<p>The reason is that the presence of such a shadow so forcibly suggests to
+the mind that the object is a prominent one intervening between the
+light and the shaded surface.<a name="FNanchor_39_39" id="FNanchor_39_39"></a><a href="#Footnote_39_39" class="fnanchor">[39]</a></p>
+
+<p>Even without differences of light and shade, by a mere arrangement of
+lines, we may produce a powerful sense of relief or solidity. A striking
+example of this is the way in which two intersecting lines sometimes
+appear to recede from the eye, as the lines <i>a a'</i>, <i>b b'</i>, in the next
+drawing, which seem to belong to a regular pattern on the ground, at
+which the eye is looking from above and obliquely.</p>
+
+<div class="figcenter">
+             <img   src="images/img088-2.jpg"
+             alt="FIG. 2." /><br />
+        FIG. 2.
+    </div>
+<p><span class='pagenum'><a name="Page_79" id="Page_79">[Pg 79]</a></span></p>
+
+<p>Again, the correct delineation of the projection of a regular
+geometrical figure, as a cube, suffices to give the eye a sense of
+relief. This effect is found to be the more striking in proportion to
+the familiarity of the form. The following drawing of a long box-shaped
+solid at once seems to stand out to the eye.</p>
+
+<div class="figcenter">
+             <img   src="images/img089.jpg"
+             alt="FIG. 3." /><br />
+        FIG. 3.
+    </div>
+
+<p>This habitual interpretation of the flat in art as answering to objects
+in relief, or having depth, can only be understood when it is remembered
+that our daily experience gives us myriads of instances in which the
+effect of such flat representations answers to solid receding forms.
+That is to say, in the case of all distant objects, in the perception of
+which the dissimilarity of the retinal pictures and the feeling of
+convergence take no part, we have to interpret solidity, and relations
+of nearer and further, by such signs as linear perspective and cast
+shadow. On the other hand, it is only in the artificial life of indoors,
+on our picture-covered walls, that we experience such effects without
+discovering corresponding realities. Hence a deeply organized habit of
+taking these impressions as answering to the solid and not to the flat.
+If our experience had been quite different;<span class='pagenum'><a name="Page_80" id="Page_80">[Pg 80]</a></span> if, for example, we had
+been brought up in an empty room, amid painted walls, and had been
+excluded from the sight of the world of receding objects outside, we
+might easily have formed an exactly opposite habit of taking the actual
+mountains, trees, etc., of the distant scene to be pictures laid on a
+flat surface.</p>
+
+<div class="figcenter">
+             <img   src="images/img090.jpg"
+             alt="FIG. 4." /><br />
+        FIG. 4.
+    </div>
+
+<p>It follows from this that, with respect to the distant parts of a scene,
+pictorial art possesses the means of perfect imitation; and here we see
+that a complete illusory effect is obtainable. I need but to refer to
+the well-known devices of linear and aerial perspective, by which this
+result is secured.<a name="FNanchor_40_40" id="FNanchor_40_40"></a><a href="#Footnote_40_40" class="fnanchor">[40]</a> The value of these means of producing illusion at
+the command of the painter, may be illustrated by the following fact,
+which I borrow from Helmholtz. If you place two pieces of cardboard
+which correspond to portions of one form at the sides and in front of a
+third piece, in the way represented above, so as just to allow the eye
+to follow the contour of this last, and then look at this arrange<span class='pagenum'><a name="Page_81" id="Page_81">[Pg 81]</a></span>ment
+from a point at some little distance with one eye, you easily suppose
+that it stands in front of the side pieces. The explanation of the
+illusion is that this particular arrangement powerfully suggests that
+the outline of the whole figure, of which the two side pieces are parts,
+is broken by an intervening object. Owing to the force of these and
+other suggestions, it is easy for the spectator, when attending to the
+background of a landscape painting, to give himself up for a moment to
+the pleasant delusion that he is looking at an actual receding scene.</p>
+
+<p>In connection with pictorial delusion, I may refer to the well-known
+fact, that the eye in a portrait seems to follow the spectator, or that
+a gun, with its muzzle pointing straight outwards, appears to turn as
+the spectator moves.<a name="FNanchor_41_41" id="FNanchor_41_41"></a><a href="#Footnote_41_41" class="fnanchor">[41]</a> These tricks of art have puzzled many people,
+yet their effect is easily understood, and has been very clearly
+explained by Sir D. Brewster, in the work already referred to (letter
+v.). They depend on the fact that a painting, being a flat projection
+only and not a solid, continues to present the front view of an object
+which it represents wherever the spectator happens to stand. Were the
+eye in the portrait a real eye, a side movement of the spectator would,
+it is evident, cause him to see less of the pupil and more of the side
+of the eyeball, and he would only continue to see the full pupil when
+the eye followed him. We regard the eye in the picture as a real eye
+having relief, and judge accordingly.<span class='pagenum'><a name="Page_82" id="Page_82">[Pg 82]</a></span></p>
+
+<p>We may fall into similar illusions respecting distance in auditory
+perception. A change of wind, an unusual stillness in the air, is quite
+sufficient to produce the sense that sounding objects are nearer than
+they actually are. The art of the ventriloquist manifestly aims at
+producing this kind of illusion. By imitating the dull effect of a
+distant voice, he is able to excite in the minds of his audience a
+powerful conviction that the sounds proceed from a distant point. There
+is little doubt that ventriloquism has played a conspicuous part in the
+arts of divination and magic.</p>
+
+
+<p class='center'><i>Misconception of Local Arrangement.</i></p>
+
+<p>Let us now pass to a class of illusions closely related to those having
+to do with distance, but involving some special kind of circumstance
+which powerfully suggests a particular arrangement in space. One of the
+most striking examples of these is the erroneous localization of a
+quality in space, that is to say, the reference of it to an object
+nearer, or further off than the right one. Thus, when we look through a
+piece of yellow glass at a dull, wintry landscape, we are disposed to
+imagine that we are looking at a sunny scene of preternatural warmth. A
+moment's reflection would tell us that the yellow tint, with which the
+objects appear to be suffused, comes from the presence of the glass;
+yet, in spite of this, the illusion persists with a curious force. The
+explanation is, of course, that the circumstances are exceptional, that
+in a vast majority of cases the impression of colour belongs to the
+object and not to an intervening medium,<a name="FNanchor_42_42" id="FNanchor_42_42"></a><a href="#Footnote_42_42" class="fnanchor">[42]</a> and that consequently we<span class='pagenum'><a name="Page_83" id="Page_83">[Pg 83]</a></span>
+tend to ignore the glass, and to refer the colour to the objects
+themselves.</p>
+
+<p>When, however, the fact of the existence of a coloured medium is
+distinctly present to the mind, we easily learn to allow for this, and
+to recognize one coloured surface correctly through a recognized medium.
+Thus, we appear to ourselves to see the reflected images of the wall,
+etc., of a room, in a bright mahogany table, not suffused with a reddish
+yellow tint, as they actually are&mdash;and may be seen to be by the simple
+device of looking at a small bit of the image through a tube, but in
+their ordinary colour. We may be said to fall into illusion here in so
+far as we overlook the exact quality of the impression actually made on
+the eye. This point will be touched on presently. Here I am concerned to
+show that this habit of allowing for the coloured medium may, in its
+turn, occasionally lead to plain and palpable illusion.</p>
+
+<p>The most striking example of this error is to be met with among the
+curious phenomena of colour-contrast already referred to. In many of
+these cases the appearance of the contrasting colour is, as I have
+observed, due to a temporary modification of the nervous substance. Yet
+it is found that this organic factor does not wholly account for the
+phenomena. For example, Meyer made the following experiment. He covered
+a piece of green paper by a sheet of thin transparent white paper. The
+colour of this double surface was, of course, a pale green. He then
+introduced a scrap of grey paper between the two sheets, and found that,
+instead of looking whitish as it really was, it looked rose-red.
+Whatever the colour of the under sheet the grey<span class='pagenum'><a name="Page_84" id="Page_84">[Pg 84]</a></span> scrap took the
+complementary hue. If, however, the piece of grey paper is put outside
+the thin sheet, it looks grey; and what is most remarkable is that when
+a second piece is put outside, the scrap inside no longer wears the
+complementary hue.</p>
+
+<p>There is here evidently something more than a change of organic
+conditions; there is an action of experience and suggestion. The reason
+of our seeing the scrap rose-red in one case and neutral grey in
+another, is that in the first instance we vividly represent to ourselves
+that we are looking at it through a greenish veil (which is, of course,
+a part of the illusion); for rose-red seen through a greenish medium
+would, as a matter of fact, be light grey, as this scrap is. Even if we
+allow that there always exists after an impression of colour a temporary
+organic disposition to see the complementary hue, this does not suffice
+as an explanation of these cases; we have to conclude further that
+imagination, led by the usual run of our experience, is here a
+co-operant factor, and helps to determine whether the complementary tint
+shall be seen or not.</p>
+
+
+<p class='center'><i>Misinterpretation of Form.</i></p>
+
+<p>More complex and circumscribed associations take part in those errors
+which we occasionally commit respecting the particular form of objects.
+This has already been touched on in dealing with artistic illusion. The
+disposition of the eye to attribute solidity to a flat drawing is the
+more powerful in proportion to the familiarity of the form. Thus, an
+outline drawing of a building is apt to stand out with special force.</p>
+
+<p>Another curious illustration of this is the pheno<span class='pagenum'><a name="Page_85" id="Page_85">[Pg 85]</a></span>menon known as the
+conversion of the concave mould or matrix of a medal into the
+corresponding convex relief. If, says Helmholtz, the mould of a medal be
+illuminated by a light falling obliquely so as to produce strong
+shadows, and if we regard this with one eye, we easily fall into the
+illusion that it is the original raised design, illuminated from <i>the
+opposite side</i>. As a matter of fact, the visual impression produced by a
+concave form with the light falling on one side, very closely resembles
+that produced by a corresponding convex form with the light falling on
+the other side. At the same time, it is found that the opposite mode of
+conversion, that is to say, the transformation of the raised into the
+depressed form, though occurring occasionally, is much less frequent.
+Now, it may be asked, why should we tend to transform the concave into
+the convex, rather than the convex into the concave? The reader may
+easily anticipate the answer from what has been said about the deeply
+fixed tendency of the eye to solidify a plane surface. We are rendered
+much more familiar, both by nature and by art, with raised (<i>cameo</i>)
+design than with depressed design (<i>intaglio</i>), and we instinctively
+interpret the less familiar form by the more familiar. This explanation
+appears to be borne out by the fact emphasized by Schroeder that the
+illusion is much more powerful if the design is that of some well-known
+object, as the human head or figure, or an animal form, or leaves.<a name="FNanchor_43_43" id="FNanchor_43_43"></a><a href="#Footnote_43_43" class="fnanchor">[43]</a></p><p><span class='pagenum'><a name="Page_86" id="Page_86">[Pg 86]</a></span></p>
+
+<p>Another illustration of this kind of illusion recently occurred in my
+own experience. Nearly opposite to my window came a narrow space between
+two detached houses. This was, of course, darker than the front of the
+houses, and the receding parallel lines of the bricks appeared to cross
+this marrow vertical shaft obliquely. I could never look at this without
+seeing it as a convex column, round which the parallel lines wound
+obliquely. Others saw it as I did, though not always with the same
+overpowering effect. I can only account for this illusion by help of the
+general tendency of the eye to solidify impressions drawn from the flat,
+together with the effect of special types of experience, more
+particularly the perception of cylindrical forms in trees, columns, etc.</p>
+
+<p>It may be added that a somewhat similar illustration of the action of
+special types of experience on the perception of individual form may be
+found in the region of hearing. The powerful disposition to take the
+finely graduated cadences of sound produced by the wind for the
+utterances of a Iranian voice, is due to the fact that this particular
+form and arrangement of sound has deeply impressed itself on our minds,
+in connection with numberless utterances of human feeling.</p>
+
+<p class='center'><i>Illusions of Recognition.</i></p>
+
+<p>As a last illustration of comparatively passive illusions, I may refer
+to the errors which we occasionally commit in recognizing objects. As I
+have already observed, the process of full and clear recognition,
+specific and individual, involves a classing of a number<span class='pagenum'><a name="Page_87" id="Page_87">[Pg 87]</a></span> of distinct
+aspects of the object, such as colour, form, etc. Accordingly, when in a
+perfectly calm state of mind we fall into illusion with respect to any
+object plainly visible, it must be through some accidental resemblance
+between the object and the other object or class of objects with which
+we identify it. In the case of individual identification such illusions
+are, of course, comparatively rare, since here there are involved so
+many characteristic differences. On the other hand, in the case of
+specific recognition there is ample room for error, especially in those
+kinds of more subtle recognition to which I have already referred. To
+"recognize" a person as a Frenchman or a military man, for example, is
+often an erroneous process. Logicians have included this kind of error
+under what they call "fallacies of observation."</p>
+
+<p>Errors of recognition, both specific and individual, are, of course,
+more easy in the case of distant objects or objects otherwise
+indistinctly seen. It is noticeable in these cases that, even when
+perfectly cool and free from emotional excitement, we tend to interpret
+such indistinct impressions according to certain favourite types of
+experience, as the human face and figure. Our interpretative imagination
+easily sees traces of the human form in cloud, rock, or tree-stump.</p>
+
+<p>Again, even when there is no error of recognition, in the sense of
+confusing one object with other objects, there may be partial illusion.
+I have remarked that the process of recognizing an object commonly
+involves an overlooking of points of diversity in the object, or aspect
+of the object, now present. And sometimes this inattention to what is
+actually present includes an error<span class='pagenum'><a name="Page_88" id="Page_88">[Pg 88]</a></span> as to the actual visual sensation of
+the moment. Thus, for example, when I look at a sheet of white paper in
+a feebly lit room, I seem to see its whiteness. If, however, I bring it
+near the window, and let the sun fall on a part of it, I at once
+recognize that what I have been seeing is not white, but a decided grey.
+Similarly, when I look at a brick viaduct a mile or two off, I appear to
+myself to recognize its redness. In fact, however, the impression of
+colour which I receive from the object is not that of brick-red at all,
+but a much less decided tint; which I may easily prove by bending my
+head downwards and letting the scene image itself on the retina in an
+unusual way, in which case the recognition of the object as a viaduct
+being less distinct, I am better able to attend to the exact shade of
+the colour.</p>
+
+<p>Nowhere is this inattention to the sensation of the moment exhibited in
+so striking a manner as in pictorial art. A picture of Meissonier may
+give the eye a representation of a scene in which the objects, as the
+human figures and horses, have a distinctness that belongs to near
+objects, but an apparent magnitude that belongs to distant objects. So
+again, it is found that the degree of luminosity or brightness of a
+pictorial representation differs in general enormously from that of the
+actual objects. Thus, according to the calculations of Helmholtz,<a name="FNanchor_44_44" id="FNanchor_44_44"></a><a href="#Footnote_44_44" class="fnanchor">[44]</a> a
+picture representing a Bedouin's white raiment in blinding sunshine,
+will, when seen in a fairly lit gallery, have a degree of luminosity
+reaching only to about one-thirtieth of that of the actual object. On
+the other hand, a painting<span class='pagenum'><a name="Page_89" id="Page_89">[Pg 89]</a></span> representing marble ruins illuminated by
+moonlight, will, under the same conditions of illumination, have a
+luminosity amounting to as much as from ten to twenty thousand times
+that of the object. Yet the spectator does not notice these stupendous
+discrepancies. The representation, in spite of its vast difference, at
+once carries the mind on to the actuality, and the spectator may even
+appear to himself, in moments of complete absorption, to be looking at
+the actual scene.</p>
+
+<p>The truly startling part of these illusions is, that the direct result
+of sensory stimulation appears to be actually displaced by a mental
+image. Thus, in the case of Meyer's experiment, of looking at the
+distant viaduct, and of recognizing an artistic representation,
+imagination seems in a measure to take the place of sensation, or to
+blind the mind to what is actually before it.</p>
+
+<p>The mystery of the process, however, greatly disappears when it is
+remembered that what we call a conscious "sensation" is really
+compounded of a result of sensory stimulation and a result of central
+reaction, of a purely passive impression and the mental activity
+involved in attending to this and classing it.<a name="FNanchor_45_45" id="FNanchor_45_45"></a><a href="#Footnote_45_45" class="fnanchor">[45]</a> This being so, a
+sensation may be modified by anything exceptional in the mode of central
+reaction of the moment. Now, in all the cases just considered, we have
+one common feature, a powerful suggestion of the presence of a
+particular object or local arrangement. This suggestion, taking the form
+of a vivid mental image, dominates and overpowers the passive<span class='pagenum'><a name="Page_90" id="Page_90">[Pg 90]</a></span>
+impression. Thus, in Meyer's experiment, the mind is possessed by the
+supposition that we are looking at the grey spot through a greenish
+medium. So in the case of the distant viaduct, we are under the mastery
+of the idea that what we see in the distance is a red brick structure.
+Once more, in the instance of looking at the picture, the spectator's
+imagination is enchained by the vivid representation of the object for
+which the picture stands, as the marble ruins in the moonlight or the
+Bedouin in the desert.</p>
+
+<p>It may be well to add that this mental uncertainty as to the exact
+nature of a present impression is necessitated by the very conditions of
+accurate perception. If, as I have said, all recognition takes place by
+overlooking points of diversity, the mind must, in course of time,
+acquire a habit of not attending to the exact quality of
+sense-impressions in all cases where the interpretation seems plain and
+obvious. Or, to use Helmholtz's words, our sensations are, in a general
+way, of interest to us only as signs of things, and if we are sure of
+the thing, we readily overlook the precise nature of the impression. In
+short, we get into the way of attending only to what is essential,
+constant, and characteristic in objects, and disregarding what is
+variable and accidental.<a name="FNanchor_46_46" id="FNanchor_46_46"></a><a href="#Footnote_46_46" class="fnanchor">[46]</a> Thus, we attend, in the first place, to the
+form of objects, the most constant and characteristic element of all,
+being comparatively<span class='pagenum'><a name="Page_91" id="Page_91">[Pg 91]</a></span> inattentive to colour, which varies with distance,
+atmospheric changes, and mode of illumination. So we attend to the
+relative magnitude of objects rather than to the absolute, and to the
+relative intensities of light and shade rather than to the absolute; for
+in so doing we are noting what is constant for all distances and modes
+of illumination, and overlooking what is variable. And the success of
+pictorial art depends on the observance of this law of perception.</p>
+
+<p>These remarks at once point out the limits of these illusions. In normal
+circumstances, an act of imagination, however vivid, cannot create the
+semblance of a sensation which is altogether absent; it can only
+slightly modify the actual impression by interfering with that process
+of comparison and classification which enters into all definite
+determination of sensational quality.</p>
+
+<p>Another great fact that has come to light in the investigation of these
+illusions is that oft-recurring and familiar types of experience leave
+permanent dispositions in the mind. As I said when describing the
+process of perception, what has been frequently perceived is perceived
+more and more readily. It follows from this that the mind will be
+habitually disposed to form the corresponding mental images, and to
+interpret impressions by help of these. The range of artistic suggestion
+depends on this. A clever draughtsman can indicate a face by a few rough
+touches, and this is due to the fact that the spectator's mind is so
+familiarized, through recurring experience and special interest, with
+the object, that it is ready to construct the requisite mental image at
+the slightest external<span class='pagenum'><a name="Page_92" id="Page_92">[Pg 92]</a></span> suggestion. And hence the risk of hasty and
+illusory interpretation.</p>
+
+<p>These observations naturally conduct us to the consideration of the
+second great group of sense-illusions, which I have marked off as active
+illusions, where the action of a pre-existing intellectual disposition
+becomes much more clearly marked, and assumes the form of a free
+imaginative transformation of reality.<span class='pagenum'><a name="Page_93" id="Page_93">[Pg 93]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER VI.</h2>
+
+<h4>ILLUSIONS OF PERCEPTION&mdash;<i>continued</i>.</h4>
+
+
+<p class='center'>B. <i>Active Illusions.</i></p>
+
+<p>When giving an account of the mechanism of perception, I spoke of an
+independent action of the imagination which tends to anticipate the
+process of suggestion from without. Thus, when expecting a particular
+friend, I recognize his form much more readily than when my mind has not
+been preoccupied with his image.</p>
+
+<p>A little consideration will show that this process must be highly
+favourable to illusion. To begin with, even if the preperception be
+correct, that is to say, if it answer to the perception, the mere fact
+of vivid expectation will affect the exact moment of the completed act
+of perception. And recent experiment shows that in certain cases such a
+previous activity of expectant attention may even lead to the illusory
+belief that the perception takes place before it actually does.<a name="FNanchor_47_47" id="FNanchor_47_47"></a><a href="#Footnote_47_47" class="fnanchor">[47]</a></p>
+<p><span class='pagenum'><a name="Page_94" id="Page_94">[Pg 94]</a></span></p>
+<p>A more palpable source of error resides in the risk of the formation of
+an inappropriate preperception. If a wrong mental image happens to have
+been formed and vividly entertained, and if the actual impression fits
+in to a certain extent with this independently formed preperception, we
+may have a fusion of the two which exactly simulates the form of a
+complete percept. Thus, for example, in the case just supposed, if
+another person, bearing some resemblance to our expected friend, chances
+to come into view, we may probably stumble into the error of taking one
+person for another.</p>
+
+<p>On the physical side, we may, agreeably to the hypothesis mentioned
+above, express this result by saying that, owing to a partial identity
+in the nervous processes involved in the anticipatory image and the
+impression, the two tend to run one into the other, constituting one
+continuous process.</p>
+
+<p>There are different ways in which this independent activity of the
+imagination may falsify our perceptions. Thus, we may voluntarily choose
+to entertain a certain image for the moment, and to look at the
+impression in a particular way, and within certain limits such
+capricious selection of an interpretation is effectual in giving a
+special significance to an impression. Or the process of independent
+preperception may go on apart from our volitions, and perhaps in spite
+of these, in which case the illusion has something of the irresistible
+necessity<span class='pagenum'><a name="Page_95" id="Page_95">[Pg 95]</a></span> of a passive illusion. Let us consider separately each mode
+of production.</p>
+
+
+<p class='center'><i>Voluntary Selection of Interpretation.</i></p>
+
+<p>The action of a capricious exercise of the imagination in relation to an
+impression is illustrated in those cases where experience and suggestion
+offer to the interpreting mind an uncertain sound, that is to say, where
+the present sense-signs are ambiguous. Here we obviously have a choice
+of interpretation. And it is found that, in these cases, what we see
+depends very much on what we wish to see. The interpretation adopted is
+still, in a sense, the result of suggestion, but of one particular
+suggestion which the fancy of the moment determines. Or, to put it
+another way, the caprice of the moment causes the attention to focus
+itself in a particular manner, to direct itself specially to certain
+aspects and relations of objects.</p>
+
+<p>The eye's interpretation of movement, already referred to, obviously
+offers a wide field for this play of selective imagination. When looking
+out of the window of a railway carriage, I can at will picture to my
+mind the trees and telegraph posts as moving objects. Sometimes the true
+interpretation is so uncertain that the least inclination to view the
+phenomenon in one way determines the result. This is illustrated in a
+curious observation of Sinsteden. One evening, on approaching a windmill
+obliquely from one side, which under these circumstances he saw only as
+a dark silhouette against a bright sky, he noticed that the sails
+appeared to go, now in one direction, now in<span class='pagenum'><a name="Page_96" id="Page_96">[Pg 96]</a></span> another, according as he
+imagined himself looking at the front or at the back of the
+windmill.<a name="FNanchor_48_48" id="FNanchor_48_48"></a><a href="#Footnote_48_48" class="fnanchor">[48]</a></p>
+
+<p>In the interpretation of geometrical drawings, as those of crystals,
+there is, as I have observed, a general tendency to view the flat
+delineation as answering to a raised object, or a body in relief,
+according to the common run of our experience. Yet there are cases where
+experience is less decided, and where, consequently, we may regard any
+particular line as advancing or receding. And it is found that when we
+vividly imagine that the drawing is that of a convex or concave surface,
+we see it to be so, with all the force of a complete perception. The
+least disposition to see it in the other way will suffice to reverse the
+interpretation. Thus, in the following drawing, the reader can easily
+see at will something answering to a truncated pyramid, or to the
+interior of a cooking vessel.</p>
+
+
+<div class="figcenter">
+             <img   src="images/img106.jpg"
+             alt="FIG. 5." /><br />
+        FIG. 5.
+    </div>
+
+<p>Similarly, in the accompanying figure of a transparent solid, I can at
+will select either of the two surfaces which approximately face the eye
+and regard<span class='pagenum'><a name="Page_97" id="Page_97">[Pg 97]</a></span> it as the nearer, the other appearing as the hinder surface
+looked at through the body.</p>
+
+<div class="figcenter">
+             <img   src="images/img107.jpg"
+             alt="FIG. 6." /><br />
+        FIG. 6.
+    </div>
+
+<p>Again, in the next drawing, taken from Schroeder, one may, by an effort
+of will, see the diagonal step-like pattern, either as the view from
+above of the edge of an advancing piece of wall at <i>a</i>, or as the view
+from below of the edge of an advancing (overhanging) piece of wall at
+<i>b</i>.</p>
+
+<div class="figcenter">
+             <img   src="images/img107-2.jpg"
+             alt="FIG. 7." /><br />
+        FIG. 7.
+    </div>
+
+<p>These last drawings are not in true perspective on either of the
+suppositions adopted, wherefore the choice is easier. But even when an
+outline form is in perspective, a strenuous effort of imagination may
+suffice to bring about a conversion of the appearance. Thus, if the
+reader will look at the drawing of the box-like solid (Fig. 3, p. 79),
+he will find that, after a trial or<span class='pagenum'><a name="Page_98" id="Page_98">[Pg 98]</a></span> two, he succeeds in seeing it as a
+<i>concave</i> figure representing the coyer and two sides of a box as looked
+at from within.<a name="FNanchor_49_49" id="FNanchor_49_49"></a><a href="#Footnote_49_49" class="fnanchor">[49]</a></p>
+
+<p>Many of my readers, probably, share in my power of variously
+interpreting the relative position of bands or stripes on fabrics such
+as wall-papers, according to wish. I find that it is possible to view
+now this stripe or set of stripes as standing out in relief upon the
+others as a ground, now these others as advancing out of the first as a
+background. The difficulty of selecting either interpretation at will
+becomes greater, of course, in those cases where there is a powerful
+suggestion of some particular local arrangement, as, for example, the
+case of patterns much brighter than the ground, and especially of such
+as represent known objects, as flowers. Yet even here a strong effort of
+imagination will often suffice to bring about a conversion of the first
+appearance.</p>
+
+<p>A somewhat similar choice of interpretation offers itself in looking at
+elaborate decorative patterns. When we strongly imagine any number of
+details to be elements of one figure, they seem to become so; and a
+given detail positively appears to alter in character according as it is
+viewed as an element of a more or less complex figure.<span class='pagenum'><a name="Page_99" id="Page_99">[Pg 99]</a></span></p>
+
+<p>These examples show what force belongs to a vivid preconception, if this
+happens to fit only very roughly the impression of the moment, that is
+to say, if the interpretative image is one of the possible suggestions
+of the impression. The play of imagination takes a wider range in those
+cases where the impression is very indefinite in character, easily
+allowing of a considerable variety of imaginative interpretation.</p>
+
+<p>I referred at the beginning of this account of sense-illusions to the
+readiness with which the mind deceives itself with respect to the nature
+and causes of the vague sensations which usually form the dim background
+of our mental life. A person of lively imagination, by trying to view
+these in a particular way, and by selectively attending to those aspects
+of the sensation which answer to the caprice of the moment, may give a
+variety of interpretations to one and the same set of sensations. For
+example, it is very easy to get confused with respect to those tactual
+and motor feelings which inform us of the position of our bodily
+members. And so, when lying in bed, and attending to the sensations
+connected with the legs, we may easily delude ourselves into supposing
+that these members are arranged in a most eccentric fashion. Similarly,
+by giving special heed to the sensations arising in connection with the
+condition of the skin at any part, we may amuse ourselves with the
+strangest fancies as to what is going on in these regions.</p>
+
+<p>Again, when any object of visual perception is indistinct or indefinite
+in form, there is plainly an opening for this capricious play of fancy
+in transforming the actual. This is illustrated in the well-known<span class='pagenum'><a name="Page_100" id="Page_100">[Pg 100]</a></span>
+pastime of discovering familiar forms, such as those of the human head
+and animals, in distant rocks and clouds, and of seeing pictures in the
+fire, and so on. The indistinct and indefinite shapes of the masses of
+rock, cloud, or glowing coal, offer an excellent field for creative
+fancy, and a person of lively imagination will discover endless forms in
+what, to an unimaginative eye, is a formless waste. Johannes M&uuml;ller
+relates that, when a child, he used to spend hours in discovering the
+outlines of forms in the partly blackened and cracked stucco of the
+house that stood opposite to his own.<a name="FNanchor_50_50" id="FNanchor_50_50"></a><a href="#Footnote_50_50" class="fnanchor">[50]</a> Here it is plain that, while
+experience and association are not wholly absent, but place certain wide
+limits on this process of castle-building, the spontaneous activity of
+the percipient mind is the great determining force.</p>
+
+<p>So much as to the influence of a perfectly unfettered voluntary
+attention on the determination of the stage of preperception, and,
+through this, of the resulting interpretation. Let us now pass to cases
+in which this direction of preperception follows not the caprice of the
+moment, but the leading of some fixed predisposition in the
+interpreter's mind. In these cases attention is no longer free, but
+fettered, only it is now fettered rather from within than from without;
+that is to say, the dominating preperception is much more the result of
+an independent bent of the imagination than of some suggestion forced on
+the mind by the actual impression of the moment.<span class='pagenum'><a name="Page_101" id="Page_101">[Pg 101]</a></span></p>
+
+<p class='center'><i>Involuntary Mental Preadjustment.</i></p>
+
+
+<p>If we glance back at the examples of capricious selection just noticed,
+we shall see that they are really limited not only by the character of
+the impression of the time, but also by the mental habits of the
+spectator. That is to say, we find that his fancy runs in certain
+definite directions, and takes certain habitual forms. It has already
+been observed that the percipient mind has very different attitudes with
+respect to various kinds of impression. Towards some it holds itself at
+a distance, while towards others it at once bears itself familiarly; the
+former are such as answer to its previous habit and bent of imagination,
+the latter such as do not so answer.</p>
+
+<p>This bent of the interpretative imagination assumes, as we have already
+seen, two forms, that of a comparatively permanent disposition, and that
+of a temporary state of expectation or mental preparedness. Illusion may
+arise in connection with either of these forms. Let us illustrate both
+varieties, beginning with those which are due to a lasting mental
+disposition.</p>
+
+<p>It is impossible here to specify all the causes of illusion residing in
+organized tendencies of the mind. The whole past mental life, with its
+particular shade of experience, its ruling emotions, and its habitual
+direction of fancy, serves to give a particular colour to new
+impressions, and so to favour illusion. There is a "personal equation"
+in perception as in belief&mdash;an amount of erroneous deviation from the
+common average view of external things, which is the outcome of
+individual temperament and habits of mind. Thus,<span class='pagenum'><a name="Page_102" id="Page_102">[Pg 102]</a></span> a naturally timid man
+will be in general disposed to see ugly and fearful objects where a
+perfectly unbiased mind perceives nothing of the kind; and the forms
+which these objects of dread will assume are determined by the character
+of his past experience, and by the customary direction of his
+imagination.</p>
+
+<p>In perfectly healthy states of mind this influence of temperament and
+mental habit on the perception of external objects is, of course, very
+limited; it shows itself more distinctly, as we shall see, in modifying
+the estimate of things in relation to the &aelig;sthetic and other feelings.
+This applies to the mythical poetical way of looking at nature&mdash;a part
+of our subject to which we shall have to return later on.</p>
+
+<p>Passing now from the effect of such permanent dispositions, let us look
+at the more striking results of temporary expectancy of mind.</p>
+
+<p>When touching on the influence of such a temporary mental attitude in
+the process of correct perception, I remarked that this readiness of
+mind might assume an indefinite or a definite form. We will examine the
+effect of each kind in the production of illusion.</p>
+
+
+<p class='center'><i>Action of Sub-Expectation.</i></p>
+
+<p>First of all, then, our minds may at the particular moment be disposed
+to entertain any one of a vaguely circumscribed group of images. Thus,
+to return to the example already referred to, when in Italy, we are in a
+state of readiness to frame any of the images that we have learnt to
+associate with this country. We may not be distinctly anticipating any
+one kind<span class='pagenum'><a name="Page_103" id="Page_103">[Pg 103]</a></span> of object, but are nevertheless in a condition of
+<i>sub-expectation</i> with reference to a large number of objects.
+Accordingly, when an impression occurs which answers only very roughly
+to one of the associated images, there is a tendency to superimpose the
+image on the impression. In this way illusion arises. Thus, a man, when
+strolling in a cathedral, will be apt to take any kind of faint hollow
+sound for the soft tones of an organ.</p>
+
+<p>The disposition to anticipate fact and reality in this way will be all
+the stronger if, as usually happens, the mental images thus lying ready
+for use have an emotional colouring. Emotion is the great disturber of
+all intellectual operations. It effects marvellous things, as we shall
+presently see, in the region of illusory belief, and its influence is
+very marked in the seemingly cooler region of external perception. The
+effect of any emotional excitement appears to be to give a preternatural
+vividness and persistence to the ideas answering to it, that is to say,
+the ideas which are its excitants, or which are otherwise associated
+with it. Owing to this circumstance, when the mind is under the
+temporary sway of any feeling, as, for example, fear, there will be a
+special readiness to interpret objects by help of images congruent with
+the emotion. Thus, a man under the control of fear will be ready to see
+any kind of fear-inspiring object whenever there is any resemblance to
+such in the things actually present to his vision. The state of awe
+which the surrounding circumstances of a spiritualist <i>s&eacute;ance</i> inspires
+produces a general readiness of mind to perceive what is strange,
+mysterious, and apparently miraculous.<span class='pagenum'><a name="Page_104" id="Page_104">[Pg 104]</a></span></p>
+
+<p>It is worth noting, perhaps, that those delightful half-illusions which
+imitative art seeks to produce are greatly favoured by such a temporary
+attitude of the interpreting imagination. In the theatre, for example,
+we are prepared for realizing the semblance of life that is to be
+unfolded before us. We come knowing that what is to be performed aims at
+representing a real action or actual series of events. We not improbably
+work ourselves into a slightly excited state in anticipation of such a
+representation. More than this, as the play progresses, the realization
+of what has gone before produces a strong disposition to believe in the
+reality of what is to follow. And this effect is proportionate to the
+degree of coherence and continuity in the action. In this way, there is
+a cumulative effect on the mind. If the action is good, the illusion, as
+every play-goer knows, is most complete towards the end.</p>
+
+<p>Were it not for all this mental preparation, the illusory character of
+the performance would be too patent to view, and our enjoyment would
+suffer. A man is often aware of this when coming into a theatre during
+the progress of a piece before his mind accommodates itself to the
+meaning of the play. And the same thing is recognizable in the fact that
+the frequenter of the theatre has his susceptibility to histrionic
+delusion increased by acquiring a habit of looking out for the meaning
+of the performance. Persons who first see a play, unless they be of
+exceptional imagination and have thought much about the theatre&mdash;as
+Charlotte Bront&euml;, for instance&mdash;hardly feel the illusion at all. At
+least, this is true of the opera, where the<span class='pagenum'><a name="Page_105" id="Page_105">[Pg 105]</a></span> departure from reality is
+so striking that the impression can hardly fail to be a ludicrous one,
+till the habit of taking the performance for what it is intended to be
+is fully formed.<a name="FNanchor_51_51" id="FNanchor_51_51"></a><a href="#Footnote_51_51" class="fnanchor">[51]</a></p>
+
+<p>A similar effect of intellectual preadjustment is observable in the
+fainter degrees of illusion produced by pictorial art. Here the
+undeceiving circumstances, the flat surface, the surroundings, and so
+on, would sometimes be quite sufficient to prevent the least degree of
+illusion, were it not that the spectator comes prepared to see a
+representation of some real object. This is our state of mind when we
+enter a picture gallery or approach what we recognize as a picture on
+the wall of a room. A savage would not "realize" a slight sketch as soon
+as one accustomed to pictorial representation, and ready to perform the
+required interpretative act.<a name="FNanchor_52_52" id="FNanchor_52_52"></a><a href="#Footnote_52_52" class="fnanchor">[52]</a></p>
+
+<p>So much as to the effect of an indefinite state of sub-expectation in
+misleading our perceptions. Let us now glance at the results of definite
+preimagination, including what are generally known as expectations.<span class='pagenum'><a name="Page_106" id="Page_106">[Pg 106]</a></span></p>
+
+<p class='center'><i>Effects of Vivid Expectation.</i></p>
+
+
+<p>Such expectations may grow out of some present objective facts, which
+serve as signs of the expected event; or they may arise by way of verbal
+suggestion; or, finally, they may be due to internal spontaneous
+imagination.</p>
+
+<p>In the first place, then, the expectations may grow out of previous
+perceptions, while, nevertheless, the direction of the expectation may
+be a wrong one. Here the interpreting imagination is, in a large sense,
+under the control of external suggestion, though, with respect to the
+particular impression that is misconstrued, it may be regarded as acting
+independently and spontaneously.</p>
+
+<p>Illustrations of this effect in producing illusion will easily occur to
+the reader. If I happen to have heard that a particular person has been
+a soldier or clergyman, I tend to see the marks of the class in this
+person, and sometimes find that this process of recognition is
+altogether illusory. Again, let us suppose that a person is expecting a
+friend by a particular train. A passenger steps out of the train bearing
+a superficial resemblance to his friend; in consequence of which he
+falls into the error of false identification.</p>
+
+<p>The delusions of the conjuror depend on a similar principle. The
+performer tells his audience that he is about to do a certain thing, for
+example, take a number of animals out of a small box which is incapable
+of holding them. The hearers, intent on what has been said, vividly
+represent to themselves the action de<span class='pagenum'><a name="Page_107" id="Page_107">[Pg 107]</a></span>scribed. And in this way their
+attention becomes bribed, so to speak, beforehand, and fails to notice
+the inconspicuous movements which would at once clear up the mystery.
+Similarly with respect to the illusions which overtake people at
+spiritualist <i>s&eacute;ances</i>. The intensity of the expectation of a particular
+kind of object excludes calm attention to what really happens, and the
+slightest impressions which answer to signs of the object anticipated
+are instantly seized by the mind and worked up into illusory
+perceptions.</p>
+
+<p>It is to be noted that even when the impression cannot be made to tally
+exactly with the expectation, the force of the latter often effects a
+grotesque confusion of the perception. If, for example, a man goes into
+a familiar room in the dark in order to fetch something, and for a
+moment forgets the particular door by which he has entered, his definite
+expectation of finding things in a certain order may blend with the
+order of impressions experienced, producing for the moment a most
+comical illusion as to the actual state of things.</p>
+
+<p>When the degree of expectation is unusually great, it may suffice to
+produce something like the counterfeit of a real sensation. This happens
+when the present circumstances are powerfully suggestive of an immediate
+event. The effect is all the more powerful, moreover, in those cases
+where the object or event expected is interesting or exciting, since
+here the mental image gains in vividness through the emotional
+excitement attending it. Thus, if I am watching a train off and know
+from all the signs that it is just about to start, I easily delude
+myself into the con<span class='pagenum'><a name="Page_108" id="Page_108">[Pg 108]</a></span>viction that it has begun to start, when it is
+really still.<a name="FNanchor_53_53" id="FNanchor_53_53"></a><a href="#Footnote_53_53" class="fnanchor">[53]</a> An intense degree of expectation may, in such cases,
+produce something indistinguishable from an actual sensation. This
+effect is seen in such common experiences as that the sight of food
+makes the mouth of a hungry man water; that the appearance of a surgical
+instrument produces a nascent sensation of pain; and that a threatening
+movement, giving a vivid anticipation of tickling, begets a feeling
+which closely approximates to the result of actual tickling.</p>
+
+<p>One or two very striking instances of such imagined sensations are given
+by Dr. Carpenter.<a name="FNanchor_54_54" id="FNanchor_54_54"></a><a href="#Footnote_54_54" class="fnanchor">[54]</a> Here is one. An officer who superintended the
+exhuming of a coffin rendered necessary through a suspicion of crime,
+declared that he already experienced the odour of decomposition, though
+it was afterwards found that the coffin was empty.<a name="FNanchor_55_55" id="FNanchor_55_55"></a><a href="#Footnote_55_55" class="fnanchor">[55]</a></p>
+
+<p>It is, of course, often difficult to say, in such cases as these, how
+far elements of actual sensation co-operate in the production of the
+illusions. Thus, in the case just mentioned, the odour of the earth may
+have been the starting-point in the illusion. In many cases, however, an
+imaginative mind appears to be capable of<span class='pagenum'><a name="Page_109" id="Page_109">[Pg 109]</a></span> transforming a vivid
+expectation into a nascent stage of sensation. Thus, a mother thinking
+of her sick child in an adjoining room, and keenly on the alert for its
+voice, will now and again fancy she really hears it when others hear
+nothing at all.</p>
+
+
+<p class='center'><i>Transition to Hallucination.</i></p>
+
+<p>It is plain that in these cases illusion approaches to hallucination.
+Imagination, instead of waiting on sensation, usurps its place and
+imitates its appearance. Such a "subjective" sensation produced by a
+powerful expectation might, perhaps, by a stretch of language, be
+regarded as an illusion, in the narrow sense, in so far as it depends on
+the suggestive force of a complete set of external circumstances; on the
+other hand, it is clearly an hallucination in so far as it is the
+production of the semblance of an external impression without any
+external agency corresponding to this.</p>
+
+<p>In the class of illusory expectations just considered the immediately
+present environment still plays a part, though a much less direct part
+than that observable in the first large group of illusions. We will now
+pass to a second mode of illusory expectation, where imagination is
+still more detached from the present surroundings.</p>
+
+<p>A common instance of this kind of expectation is the so-called
+"intuition," or presentiment; that something is going to happen, which
+expectation has no basis in fact. It does not matter whether the
+expectation has arisen by way of another's words or by way<span class='pagenum'><a name="Page_110" id="Page_110">[Pg 110]</a></span> of personal
+inclinations. A strong wish for a thing will, in an exalted state of
+mind, beget a vivid anticipation of it. This subject will be touched on
+again under the Illusions of Belief. Here I am concerned to point out
+that such presentiments are fertile sources of sense-illusion. The
+history of Church miracles, visions, and the like amply illustrates the
+effect of a vivid anticipation in falsifying the perceptions of external
+things.</p>
+
+<p>In persons of a lively imagination any recent occupation of the mind
+with a certain kind of mental image may suffice to beget something
+equivalent to a powerful mode of expectation. For example, we are told
+by Dr. Tuke that on one occasion a lady, whose imagination had been
+dwelling on the subject of drinking fountains, "thought she saw in a
+road a newly erected fountain, and even distinguished an inscription
+upon it, namely, 'If any man thirst, let him come unto Me, and drink.'
+She afterwards found that what she had actually seen was only a few
+scattered stones."<a name="FNanchor_56_56" id="FNanchor_56_56"></a><a href="#Footnote_56_56" class="fnanchor">[56]</a> In many cases there seems to be a temporary
+preternatural activity of the imagination in certain directions, of
+which no very obvious explanation is discoverable. Thus, we sometimes
+find our minds dwelling on some absent friend, without being able to
+give any reason for this mental preoccupation. And in this way arise
+strong temporary leanings to illusory perception. It may be said,
+indeed, that all unwonted activity of the imagination, however it
+arises, has as its immediate result a temporary mode of expectation,
+definite or<span class='pagenum'><a name="Page_111" id="Page_111">[Pg 111]</a></span> indefinite, which easily confuses our perceptions of
+external things.</p>
+
+<p>In proportion as this pre-existing imaginative impulse becomes more
+powerful, the amount of actual impression necessary to transform the
+mental image into an illusory perception becomes less; and, what is more
+important, this transformation of the internal image involves a larger
+and larger displacement of the actual impression of the moment. A man
+whose mind is at the time strongly possessed by one kind of image, will
+tend to project this outwards with hardly any regard to the actual
+external circumstances.</p>
+
+<p>This state of things is most completely illustrated in many of the
+grosser illusions of the insane. Thus, when a patient takes any small
+objects, as pebbles, for gold and silver, under the influence of the
+dominant idea of being a millionaire, it is obvious that external
+suggestion has very little to do with the self-deception. The confusions
+into which the patient often falls with respect to the persons before
+him show the same state of mind; for in many cases there is no
+discoverable individual resemblance between the person actually present
+and the person for whom he is taken.</p>
+
+<p>It is evident that when illusion reaches this stage, it is scarcely
+distinguishable from what is specially known as hallucination. As I have
+remarked in setting out, illusion and hallucination shade one into the
+other much too gradually for us to draw any sharp line of demarcation
+between them. And here we see that hallucination differs from illusion
+only in the proportion in which the causes are present. When the
+internal imaginative impulse reaches a certain strength,<span class='pagenum'><a name="Page_112" id="Page_112">[Pg 112]</a></span> it becomes
+self-sufficient, or independent of any external impression.</p>
+
+<p>This intimate relation between the extreme form of active illusion and
+hallucination may be seen, too, by examining the physical conditions of
+each. As I have already remarked, active illusion has for its
+physiological basis a state of sub-excitation, or an exceptional
+condition of irritability in the structures engaged in the act of
+interpretative imagination. The greater the degree of this irritability,
+the less will be the force of external stimulation needed to produce the
+effect of excitation, and the more energetic will be the degree of this
+excitation. Moreover, it is plain that this increase in the strength of
+the excitation will involve an extension of the area of excitation till,
+by-and-by, the peripheral regions of the nervous system may be involved
+just as in the case of external stimulation. This accounts for the
+gradual displacement of the impression of the moment by the mental
+image. It follows that when the irritability reaches a certain degree,
+the amount of external stimulus needed may become a vanishing quantity,
+or the state of sub-excitation may of itself develop into one of full
+activity.</p>
+
+
+<p class='center'><i>Hallucinations.</i></p>
+
+<p>I do not propose to go very fully into the description and explanation
+of hallucinations here, since they fall to a large extent under the
+category of distinctly pathological phenomena. Yet our study of
+illusions would not be complete without a glance at this part of the
+subject.<span class='pagenum'><a name="Page_113" id="Page_113">[Pg 113]</a></span></p>
+
+<p>Hallucination, by which I mean the projection of a mental image outwards
+when there is no external agency answering to it, assumes one of two
+fairly distinct forms: it may present itself either as a semblance of an
+external impression with the minimum amount of interpretation, or as a
+counterfeit of a completely developed percept. Thus, a visual
+hallucination may assume the aspect of a sensation of light or colour
+which we vaguely refer to a certain region of the external world, or of
+a vision of some recognizable object. All of us frequently have
+incomplete visual and auditory hallucinations of the first order,
+whereas the complete hallucinations of the second order are
+comparatively rare. The first I shall call rudimentary, the second
+developed, hallucinations.</p>
+
+<p>Rudimentary hallucinations may have either a peripheral or a central
+origin. They may first of all have their starting-point in those
+subjective sensations which, as we have seen, are connected with certain
+processes set up in the peripheral regions of the nervous system. Or,
+secondly, they may originate in a certain preternatural activity of the
+sensory centres, or "sensorium," in what has been called by German
+physiologists an automatic excitation of the central structures, which
+activity may probably diffuse itself downwards to the peripheral regions
+of the nerves. Baillarger would call hallucinations of the former class
+"psycho-sensorial," those of the latter class purely "psychical,"
+hallucinations.<a name="FNanchor_57_57" id="FNanchor_57_57"></a><a href="#Footnote_57_57" class="fnanchor">[57]</a></p>
+<p><span class='pagenum'><a name="Page_114" id="Page_114">[Pg 114]</a></span></p>
+<p>It is often a matter of great difficulty to determine which part of the
+nervous system is originally concerned in these rudimentary
+hallucinations. It is probable that in normal life they are most
+frequently due to peripheral disturbance. And it seems reasonable to
+suppose that where the hallucination remains in this initial stage of a
+very incompletely interpreted visual or auditory impression, whether in
+normal or abnormal life, its real physiological source is the periphery.
+For the automatic excitation of the centres would pretty certainly issue
+in the semblance of some definite, familiar variety of sense-impression
+which, moreover, as a part of a complex state known as a percept, would
+instantly present itself as a completely formed quasi-percept. In truth,
+we may pretty safely argue that if it is the centre which is directly
+thrown into a state of activity, it will be thrown into the usual
+complex, that is to say, <i>perceptional</i>, mode of activity.</p>
+
+<p>Let us now turn to hallucinations properly so called, that is to say,
+completely developed quasi-percepts. These commonly assume the form of
+visual or auditory hallucinations. Like the incomplete hallucinations,
+they may have their starting-point either in some disturbance in the
+peripheral regions of the nervous system or in the automatic activity of
+the central structures: or, to use the language of Baillarger, we may
+say that they are either "psycho-sensorial" or purely "psychical." A
+subjective visual sensation, arising from certain conditions in the
+retina and connected portions of the optic nerve, may by chance resemble
+a familiar impression, and so be at once interpreted as an effect of a
+particular external object.<span class='pagenum'><a name="Page_115" id="Page_115">[Pg 115]</a></span> More frequently, however, the automatic
+activity of the centres must be regarded, either in part or altogether,
+as the physiological cause of the phenomenon. This is clearly the case
+when, on the subjective side, the hallucination answers to a preceding
+energetic activity of the imagination, as in the case of the visionary
+and the monomaniac. Sometimes, however, as we have seen, the
+hallucinatory percept answers to previous prolonged acts of perception,
+leaving a kind of reverberation in the structures concerned; and in this
+case it is obviously impossible to say whether the peripheral or central
+regions (if either) have most to do with the hallucination.<a name="FNanchor_58_58" id="FNanchor_58_58"></a><a href="#Footnote_58_58" class="fnanchor">[58]</a></p>
+
+<p>The classifications of the causes of hallucination to be met with in the
+works of pathologists, bear out the distinction just drawn. Griesinger
+tells us (<i>op. cit.</i>, pp. 94, 95) that the general causes of
+hallucination are: (1) Local disease of the organ of sense; (2) a state
+of deep exhaustion either of mind or of body; (3) morbid emotional
+states, such as fear; (4) outward calm and stillness between sleeping
+and waking; and (5) the action of certain poisons, as haschisch, opium,
+belladonna. The first cause points pretty distinctly to a peripheral
+origin, whereas the others appear to refer mainly, if not exclusively,
+to central derangements.<span class='pagenum'><a name="Page_116" id="Page_116">[Pg 116]</a></span> Excessive fatigue appears to predispose the
+central structures to an abnormal kind of activity, and the same effect
+may be brought about by emotional agitation and by the action of
+poisons. The fourth case mentioned here, absence of external
+stimulation, would naturally raise the nervous structures to an
+exceptional pitch of excitability. Such a condition would, moreover,
+prove favourable to hallucination by blurring the distinction between
+mental image and actual impression.</p>
+
+
+<p class='center'><i>Hallucinations of Normal Life.</i></p>
+
+<p>In normal life, perfect hallucinations, in the strict sense as distinct
+from illusions, are comparatively rare. Fully developed persistent
+hallucinations, as those of Nicolai, the Berlin bookseller, and of Mrs.
+A&mdash;&mdash;, the lady cited by Sir D. Brewster, in his <i>Letters on Natural
+Magic</i>, point to the presence of incipient nervous disorder. In healthy
+life, on the other hand, while everybody is familiar with subjective
+sensations such as flying spots, phosphenes, ringing in the ears, few
+fall into the error of seeing or hearing distinct recognizable objects
+in the absence of all external impressions. In the lives of eminent men
+we read of such phenomena as very occasional events. Malebranche, for
+example, is said to have heard the voice of God calling him. Descartes
+says that, after a long confinement, he was followed by an invisible
+person, calling him to pursue his search for truth. Dr. Johnson narrates
+that he once heard his absent mother calling him. Byron tells us that he
+was sometimes visited by spectres. Goethe records that he once saw an
+exact counterpart of him<span class='pagenum'><a name="Page_117" id="Page_117">[Pg 117]</a></span>self coming towards him. Sir Walter Scott is
+said to have seen a phantom of the dead Byron. It is possible that all
+of us are liable to momentary hallucinations at times of exceptional
+nervous exhaustion, though they are too fugitive to excite our
+attention.</p>
+
+<p>When not brought on by exhaustion or artificial means, the
+hallucinations of the sane have their origin in a preternatural power of
+imagination. It is well known that this power can be greatly improved by
+attention and cultivation. Goethe used to exercise himself in watching
+for ocular spectra, and could at will transform these subjective
+sensations into definite forms, such as flowers; and Johannes M&uuml;ller
+found he had the same power.<a name="FNanchor_59_59" id="FNanchor_59_59"></a><a href="#Footnote_59_59" class="fnanchor">[59]</a> Stories are told of portrait painters
+who could summon visual images of their sitters with a vividness equal
+to that of reality, and serving all the purposes of their art. Mr.
+Galton's interesting inquiries into the power of "visualizing" would
+appear to prove that many people can at will sport on the confines of
+the phantom world of hallucination. There is good reason to think that
+imaginative children tend to confuse mental images and percepts.<a name="FNanchor_60_60" id="FNanchor_60_60"></a><a href="#Footnote_60_60" class="fnanchor">[60]</a></p>
+<p><span class='pagenum'><a name="Page_118" id="Page_118">[Pg 118]</a></span></p>
+<p class='center'><i>The Hallucinations of Insanity.</i></p>
+
+
+<p>The hallucinations of the insane are but a fuller manifestation of
+forces that we see at work in normal life. Their characteristic is that
+they simulate the form of distinctly present objects, the existence of
+which is not instantly contradicted by the actual surroundings of the
+moment.<a name="FNanchor_61_61" id="FNanchor_61_61"></a><a href="#Footnote_61_61" class="fnanchor">[61]</a> The hallucinations have their origin partly in subjective
+sensations, which are probably connected with peripheral disturbances,
+partly and principally in central derangements.<a name="FNanchor_62_62" id="FNanchor_62_62"></a><a href="#Footnote_62_62" class="fnanchor">[62]</a> These include
+profound emotional changes, which affect the ruling mental tone, and
+exert a powerful influence on the course of the mental images. The
+hallucinations of insanity are due to a projection of mental images
+which have, owing to certain circumstances, gained a preternatural
+persistence and vividness. Sometimes it is the images that have been
+dwelt on with passionate longing before the disease, sometimes those
+which have grown most habitual through the mode of daily
+occupa<span class='pagenum'><a name="Page_119" id="Page_119">[Pg 119]</a></span>tion,<a name="FNanchor_63_63" id="FNanchor_63_63"></a><a href="#Footnote_63_63" class="fnanchor">[63]</a> and sometimes those connected with some incident at or
+near the time of the commencement of the disease.</p>
+
+<p>In mental disease, auditory hallucinations play a part no less
+conspicuous than visual.<a name="FNanchor_64_64" id="FNanchor_64_64"></a><a href="#Footnote_64_64" class="fnanchor">[64]</a> Patients frequently complain of having
+their thoughts spoken to them, and it is not uncommon for them to
+imagine that they are addressed by a number of voices at the same
+time.<a name="FNanchor_65_65" id="FNanchor_65_65"></a><a href="#Footnote_65_65" class="fnanchor">[65]</a></p>
+
+<p>These auditory hallucinations offer a good opportunity for studying the
+gradual growth of centrally originating hallucinations. In the early
+stages of the disease, the patient partly distinguishes his
+representative from his preservative sounds. Thus, he talks of sermons
+being composed to him <i>in his head</i>. He calls these "internal voices,"
+or "voices of the soul." It<span class='pagenum'><a name="Page_120" id="Page_120">[Pg 120]</a></span> is only when the disease gains ground and
+the central irritability increases that these audible thoughts become
+distinctly projected as external sounds into more or less definite
+regions of the environment. And it is exceedingly curious to notice the
+different directions which patients give to these sounds, referring them
+now to a quarter above the head, now to a region below the floor, and so
+on.<a name="FNanchor_66_66" id="FNanchor_66_66"></a><a href="#Footnote_66_66" class="fnanchor">[66]</a></p>
+
+
+<p class='center'><i>Range of Sense-Illusions.</i></p>
+
+<p>And now let us glance back to see the path we have traversed. We set out
+with an account of perfectly normal perception, and found, even here, in
+the projection of our sensations of colour, sound, etc., into the
+environment or to the extremities of the organism, something which, from
+the point of view of physical science, easily wears the appearance of an
+ingredient of illusion.</p>
+
+<p>Waiving this, however, and taking the word illusion as commonly
+understood, we find that it begins when the element of imagination no
+longer answers to a present reality or external fact in any sense of
+this expression. In its lowest stages illusion closely counterfeits
+correct perception in the balance of the direct factor, sensation, and
+the indirect factor, mental reproduction or imagination. The degree of
+illusion increases in proportion as the imaginative element gains<span class='pagenum'><a name="Page_121" id="Page_121">[Pg 121]</a></span> in
+force relatively to the present impression; till, in the wild illusions
+of the insane, the amount of actual impression becomes evanescent. When
+this point is reached, the act of imagination shows itself as a purely
+creative process, or an hallucination.</p>
+
+<p>While we may thus trace the progress of illusion towards hallucination
+by means of the gradual increase in force and extent of the imaginative,
+or indirect, as opposed to the sensuous, or direct, element in
+perception, we have found a second starting-point for this movement in
+the mechanism of sensation, involving, as it does, the occasional
+production of "subjective sensations." Such sensations constitute a
+border-land between the regions of illusion in the narrow sense, and
+hallucination. In their simplest and least developed form they may be
+regarded, at least in the case of hearing and sight, as partly
+hallucinatory; and they serve as a natural basis for the construction of
+complete hallucinations, or hallucinatory percepts.</p>
+
+<p>In these different ways, then, the slight, scarcely noticeable illusions
+of normal life lead up to the most startling hallucinations of abnormal
+life. From the two poles of the higher centres of attention and
+imagination on the one side, and the lower regions of nervous action
+involved in sensation on the other side, issue forces which may, under
+certain circumstances, develop into full hallucinatory percepts. Thus
+closely is healthy attached to morbid mental life. There seems to be no
+sudden break between our most sober every-day recognitions of familiar
+objects and the wildest hallucinations of the demented. As we pass from
+the former to the latter, we find that there is<span class='pagenum'><a name="Page_122" id="Page_122">[Pg 122]</a></span> never any abrupt
+transition, never any addition of perfectly new elements, but only that
+the old elements go on combining in ever new proportions.</p>
+
+<p>The connection between the illusory side of our life and insanity may be
+seen in another way. All illusion has as its negative condition an
+interruption of the higher intellectual processes, the due control of
+our mental representations by reflection and reason. In the case of
+passive illusions, the error arises from our inability to subordinate
+the suggestion made by some feature of the present impression to the
+result of a fuller inspection of the object before us, or of a wider
+reflection on the past. In other words, our minds are dominated by the
+partial and the particular, to the exclusion of the total or the
+general. In active illusions, again, the powers of judgment and
+reflection, including those of calm perception itself, temporarily
+vacate their throne in favour of imagination. And this same suspension
+of the higher intellectual functions, the stupefaction of judgment and
+reflection made more complete and permanent, is just what characterizes
+insanity.</p>
+
+<p>We may, perhaps, express this point of connection between the illusions
+of normal life and insanity by help of a physiological hypothesis. If
+the nervous system has been slowly built up, during the course of human
+history, into its present complex form, it follows that those nervous
+structures and connections which have to do with the higher intellectual
+processes, or which represent the larger and more general relations of
+our experience, have been most recently evolved. Consequently, they
+would be the least deeply organized,<span class='pagenum'><a name="Page_123" id="Page_123">[Pg 123]</a></span> and so the least stable; that is
+to say, the most liable to be thrown <i>hors de combat</i>. This is what
+happens temporarily in the case of the sane, when the mind is held fast
+by an illusion. And, in states of insanity, we see the process of
+nervous dissolution beginning with these same nervous structures, and so
+taking the reverse order of the process of evolution.<a name="FNanchor_67_67" id="FNanchor_67_67"></a><a href="#Footnote_67_67" class="fnanchor">[67]</a> And thus, we
+may say that throughout the mental life of the most sane of us, these
+higher and more delicately balanced structures are constantly in danger
+of being reduced to that state of inefficiency, which in its full
+manifestation is mental disease.</p>
+
+<p>Does this way of putting the subject seem alarming? Is it an appalling
+thought that our normal mental life is thus intimately related to
+insanity, and graduates away into it by such fine transitions? A
+moment's reflection will show that the case is not so bad as it seems.
+It is well to remind ourselves that the brain is a delicately adjusted
+organ, which very easily gets disturbed, and that the best of us are
+liable to become the victims of absurd illusion if we habitually allow
+our imaginations to be overheated, whether by furious passion or by
+excessive indulgence in the pleasures of day-dreaming, or in the
+intoxicating mysteries of spiritualist <i>s&eacute;ances</i>. But if we take care to
+keep our heads cool and avoid unhealthy degrees of mental excitement, we
+need not be very anxious on the ground of our liability to this kind of
+error. As I have tried to show, our most frequent illusions are
+necessarily connected with something exceptional, either in the<span class='pagenum'><a name="Page_124" id="Page_124">[Pg 124]</a></span>
+organism or in the environment. That is to say, it is of the nature of
+illusion in healthy conditions of body and mind to be something very
+occasional and relatively unimportant. Our perceptions may be regarded
+as the reaction of the mind on the impressions borne in from the
+external world, or as a process of adjustment of internal mental
+relations to external physical relations. If this process is, in the
+main, a right one, we need not greatly trouble, because it is not
+invariably so. We should accept the occasional failure of the
+intellectual mechanism as an inseparable accompaniment of its general
+efficiency.</p>
+
+<p>To this it must be added that many of the illusions described above can
+hardly be called cases of non-adaptation at all, since they have no
+relation to the practical needs of life, and consequently are, in a
+general way, unattended to. In other cases, again, namely, where the
+precise nature of a present sensation, being practically an unimportant
+matter, is usually unattended to, as in the instantaneous recognition of
+objects by the eye under changes of illumination, etc., the illusion is
+rather a part of the process of adaptation, since it is much more
+important to recognize the permanent object signified by the sensation
+than the precise nature of the present sensational "sign" itself.</p>
+
+<p>Finally, it should never be forgotten that in normal states of mind
+there is always the possibility of rectifying an illusion. What
+distinguishes abnormal from normal mental life is the persistent
+occupation of the mind by certain ideas, so that there is no room for
+the salutary corrective effect of reflection on the actual<span class='pagenum'><a name="Page_125" id="Page_125">[Pg 125]</a></span> impression
+of the moment, by which we are wont to "orientate," or take our bearings
+as to the position of things about us. In sleep, and in certain
+artificially produced states, much the same thing presents itself.
+Images become realities just because they are not instantly recognized
+as such by a reference to the actual surroundings of the moment. But in
+normal waking life this power of correction remains with us. We may not
+exercise it, it is true, and thus the illusion will tend to become more
+or less persistent and recurring; for the same law applies to true and
+to false perception: repetition makes the process easier. But if we only
+choose to exert ourselves, we can always keep our illusions in a nascent
+or imperfectly developed stage. This applies not only to those
+half-illusions into which we voluntarily fall, but also to the more
+irresistible passive illusions, and those arising from an over-excited
+imagination. Even persons subject to hallucinations, like Nicolai of
+Berlin, learn to recognize the unreal character of these phantasms. On
+this point the following bit of autobiography from the pen of Coleridge
+throws an interesting light. "A lady (he writes) once asked me if I
+believed in ghosts and apparitions. I answered with truth and
+simplicity, No, madam, I have seen far too many myself."<a name="FNanchor_68_68" id="FNanchor_68_68"></a><a href="#Footnote_68_68" class="fnanchor">[68]</a> However
+irresistible our sense-illusions may be, so long as we are under the
+sway of particular impressions or mental images, we can, when resolved
+to do so, un<span class='pagenum'><a name="Page_126" id="Page_126">[Pg 126]</a></span>deceive ourselves by carefully attending to the actual
+state of things about us. And in many cases, when once the correction is
+made, the illusion seems an impossibility. By no effort of imagination
+are we able to throw ourselves back into the illusory mental condition.
+So long as this power of dispelling the illusion remains with us, we
+need not be alarmed at the number and variety of the momentary
+misapprehensions to which we are liable.<span class='pagenum'><a name="Page_127" id="Page_127">[Pg 127]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER VII.</h2>
+
+<h4>DREAMS.</h4>
+
+
+<p>The phenomena of dreams may well seem at first sight to form a world of
+their own, having no discoverable links of connection with the other
+facts of human experience. First of all, there is the mystery of sleep,
+which quietly shuts all the avenues of sense and so isolates the mind
+from contact with the world outside. To gaze at the motionless face of a
+sleeper temporarily rapt from the life of sight, sound, and
+movement&mdash;which, being common to all, binds us together in mutual
+recognition and social action&mdash;has always something awe-inspiring. This
+external inaction, this torpor of sense and muscle, how unlike to the
+familiar waking life, with its quick responsiveness and its overflowing
+energy! And then, if we look at dreams from the inside, we seem to find
+but the reverse face of the mystery. How inexpressibly strange does the
+late night-dream seem to a person on waking! He feels he has been seeing
+and hearing things no less real than those of waking life; but things
+which belong to an unfamiliar world, an order of sights and a sequence
+of events quite unlike those of waking experience; and<span class='pagenum'><a name="Page_128" id="Page_128">[Pg 128]</a></span> he asks himself
+in his perplexity where that once-visited region really lies, or by what
+magic power it was suddenly and for a moment created for his vision. In
+truth, the very name of dream suggests something remote and mysterious,
+and when we want to characterize some impression or scene which by its
+passing strangeness filled us with wonder, we naturally call it
+dream-like.</p>
+
+
+<p class='center'><i>Theories of Dreams.</i></p>
+
+<p>The earliest theories respecting dreams illustrate very clearly this
+perception of the remoteness of dream-life from waking experience. By
+the simple mind of primitive man this dream-world is regarded as similar
+in its nature or structure to our common world, only lying remote from
+this. The savage conceives that when he falls asleep, his second self
+leaves his familiar body and journeys forth to unfamiliar regions, where
+it meets the departed second selves of his dead ancestors, and so on.
+From this point of view, the experience of the night, though equal in
+reality to that of the day, is passed in a wholly disconnected
+region.<a name="FNanchor_69_69" id="FNanchor_69_69"></a><a href="#Footnote_69_69" class="fnanchor">[69]</a></p>
+
+<p>A second and more thoughtful view of dreams, marking a higher grade of
+intellectual culture, is that these visions of the night are symbolic
+pictures unfolded to the inner eye of the soul by some supernatural
+being. The dream-experience is now, in a sense, less real than it was
+before, since the phantasms that wear the guise of objective realities
+are simply<span class='pagenum'><a name="Page_129" id="Page_129">[Pg 129]</a></span> images spread out to the spirit's gaze, or the direct
+utterance of a divine message. Still, this mysterious contact of the
+mind with the supernatural is regarded as a fact, and so the dream
+assumes the appearance of a higher order of experience. Its one point of
+attachment to the experience of waking life lies in its symbolic
+function; for the common form which this supernatural view assumes is
+that the dream is a dim prevision of coming events. Artemidorus, the
+great authority on dream interpretation (<i>oneirocritics</i>) for the
+ancient world, actually defines a dream as "a motion or fiction of the
+soul in a diverse form signifying either good or evil to come;" and even
+a logician like Porphyry ascribes dreams to the influence of a good
+demon, who thereby warns us of the evils which another and bad demon is
+preparing for us. The same mode of viewing dreams is quite common
+to-day, and many who pride themselves on a certain intellectual culture,
+and who imagine themselves to be free from the weakness of superstition,
+are apt to talk of dreams as of something mysterious, if not distinctly
+ominous. Nor is it surprising that phenomena which at first sight look
+so wild and lawless, should still pass for miraculous interruptions of
+the natural order of events.<a name="FNanchor_70_70" id="FNanchor_70_70"></a><a href="#Footnote_70_70" class="fnanchor">[70]</a></p>
+
+<p>Yet, in spite of this obvious and impressive element of the mysterious
+in dream-life, the scientific impulse to illuminate the less known by
+the better known has long since begun to play on this obscure subject.
+Even in the ancient world a writer might here and<span class='pagenum'><a name="Page_130" id="Page_130">[Pg 130]</a></span> there be found, like
+Democritus or Aristotle, who was bold enough to put forward a natural
+and physical explanation of dreams. But it has been the work of modern
+science to provide something like an approximate solution of the
+problem. The careful study of mental life in its intimate union with
+bodily operations, and the comparison of dream-combinations with other
+products of the imagination, normal as well as morbid, have gradually
+helped to dissolve a good part of the mystery which once hung like an
+opaque mist about the subject. In this way, our dream-operations have
+been found to have a much closer connection with our waking experiences
+than could be supposed on a superficial view. The materials of our
+dreams are seen, when closely examined, to be drawn from our waking
+experience. Our waking consciousness acts in numberless ways on our
+dreams, and these again in unsuspected ways influence our waking mental
+life.<a name="FNanchor_71_71" id="FNanchor_71_71"></a><a href="#Footnote_71_71" class="fnanchor">[71]</a> Not only so, it is found that the quaint chaotic play of
+images in dreams illustrates mental processes and laws which are
+distinctly observable in waking thought. Thus, for example, the apparent
+objective reality of these visions has been accounted for, without the
+need of resorting to any supernatural agency, in the light of a vast
+assemblage of facts gathered from the by-ways, so to speak, of waking
+mental life. I need hardly add that I refer to the illusions of sense
+dealt with in the foregoing chapters.</p>
+
+<p>Dreams are to a large extent the semblance of<span class='pagenum'><a name="Page_131" id="Page_131">[Pg 131]</a></span> external perceptions.
+Other psychical phenomena, as self-reflection, emotional activity, and
+so on, appear in dream-life, but they do so in close connection with
+these quasi-perceptions. The name "vision," given by old writers to
+dreams, sufficiently points out this close affinity of the mental
+phenomena to sense-perception; and so far as science is concerned, they
+must be regarded as a peculiar variety of sense-illusion. Hence the
+appropriateness of studying them in close connection with the illusions
+of perception of the waking state. Though marked off by the presence of
+very exceptional physiological conditions, they are largely intelligible
+by help of these physiological and psychological principles which we
+have just been considering.</p>
+
+
+<p class='center'><i>The State of Sleep.</i></p>
+
+<p>The physiological explanation of dreams must, it is plain, set out with
+an account of the condition of the organism known as sleep. While there
+is here much that is uncertain, there are some things which are fairly
+well known. Recent physiological observation has gone to prove that
+during sleep all the activities of the organism are appreciably lowered.
+Thus, for example, according to Testa, the pulse falls by about
+one-fifth. This lowering of the organic functions appears, under
+ordinary circumstances, to increase towards midnight, after which there
+is a gradual rising.</p>
+
+<p>The nervous system shares in this general depression of the vital
+activities. The circulation being slower, the process of reparation and
+nutrition of the nerves is retarded, and so their degree of excitability
+diminished.<span class='pagenum'><a name="Page_132" id="Page_132">[Pg 132]</a></span> This is clearly seen in the condition of the peripheral
+regions of the nervous system, including the sense-organs, which appear
+to be but very slightly acted on by their customary stimuli.</p>
+
+<p>The nervous centres must participate in this lethargy of the system. In
+other words, the activity of the central substance is lowered, and the
+result of this is plainly seen in what is usually thought of as the
+characteristic feature of sleep, namely, a transition from vigorous
+mental activity or intense and clear consciousness, to comparative
+inactivity or faint and obscure consciousness. The cause of this
+condition of the centres is supposed to be the same as that of the
+torpidity of all the other organs in sleep, namely, the retardation of
+the circulation. But, though there is no doubt as to this, the question
+of the proximate physiological conditions of sleep is still far from
+being settled. Whether during sleep the blood-vessels of the brain are
+fuller or less full than during waking, is still a moot point. Also the
+qualitative condition of the blood in the cerebral vessels is still a
+matter of discussion.<a name="FNanchor_72_72" id="FNanchor_72_72"></a><a href="#Footnote_72_72" class="fnanchor">[72]</a></p>
+
+<p>Since the effect of sleep is to lower central activity, the question
+naturally occurs whether the nervous centres are ever rendered inactive
+to such an extent as to interrupt the continuity of our conscious life.
+This question has been discussed from the point of view of the
+metaphysician, of the psychologist, and of the physiologist, and in no
+case is perfect unanimity to be found. The metaphysical question,
+whether the soul as a spiritual substance is capable of being wholly
+in<span class='pagenum'><a name="Page_133" id="Page_133">[Pg 133]</a></span>active, or whether it is not in what seem the moments of profoundest
+unconsciousness partially awake&mdash;the question so warmly discussed by the
+Cartesians, Leibnitz, etc.&mdash;need not detain us here.</p>
+
+<p>Of more interest to us are the psychological and the physiological
+discussions. The former seeks to settle the question by help of
+introspection and memory. On the one side, it is urged against the
+theory of unbroken mental activity, that we remember so little of the
+lowered consciousness of sleep.<a name="FNanchor_73_73" id="FNanchor_73_73"></a><a href="#Footnote_73_73" class="fnanchor">[73]</a> To this it is replied that our
+forgetfulness of the contents of dream-consciousness, even if this were
+unbroken, would be fully accounted for by the great dissimilarity
+between dreaming and waking mental life. It is urged, moreover, on this
+side that a sudden rousing of a man from sleep always discovers him in
+the act of dreaming, and that this goes to prove the uniform connection
+of dreaming and sleeping. This argument, again, may be met by the
+assertion that our sense of the duration of our dreams is found to be
+grossly erroneous; that, owing to the rapid succession of the images,
+the <i>realization</i> of which would involve a long duration, we enormously
+exaggerate the length of dreams in retrospection.<a name="FNanchor_74_74" id="FNanchor_74_74"></a><a href="#Footnote_74_74" class="fnanchor">[74]</a> From this it is
+argued that the dream which is recalled on our being suddenly awakened
+may have had its whole course during the transition state of waking.</p>
+
+<p>Again, the fact that a man may resolve, on going to sleep, to wake at a
+certain hour, has often been cited in<span class='pagenum'><a name="Page_134" id="Page_134">[Pg 134]</a></span> proof of the persistence of a
+degree of mental activity even in perfectly sound sleep. The force of
+this consideration, however, has been explained away by saying that the
+anticipation of rising at an unusual hour necessarily produces a slight
+amount of mental disquietude, which is quite sufficient to prevent sound
+sleep, and therefore to expose the sleeper to the rousing action of
+faint external stimuli.</p>
+
+<p>While the purely psychological method is thus wholly inadequate to solve
+the question, physiological reasoning appears also to be not perfectly
+conclusive. Many physiologists, not unnaturally desirous of upsetting
+what they regard as a gratuitous metaphysical hypothesis, have
+pronounced in favour of an absolutely dreamless or unconscious sleep.
+From the physiological point of view, there is no mystery in a totally
+suspended mental activity. On the other hand, there is much to be said
+on the opposite side, and perhaps it may be contended that the purely
+physiological evidence rather points to the conclusion that central
+activity, however diminished during sleep, always retains a minimum
+degree of intensity. At least, one would be disposed to argue in this
+way from the analogy of the condition of the other functions of the
+organism during sleep. Possibly this modicum of positive evidence may
+more than outweigh any slight presumption against the doctrine of
+unbroken mental activity drawn from the negative circumstance that we
+remember so little of our dream-life.<a name="FNanchor_75_75" id="FNanchor_75_75"></a><a href="#Footnote_75_75" class="fnanchor">[75]</a></p>
+
+<p>Such being the state of physiological knowledge<span class='pagenum'><a name="Page_135" id="Page_135">[Pg 135]</a></span> respecting the
+immediate conditions of sleep, we cannot look for any certain
+information on the nature of that residual mode of cerebral activity
+which manifests itself subjectively in dreams. It is evident, indeed,
+that this question can only be fully answered when the condition of the
+brain as a whole during sleep is understood. Meanwhile we must be
+content with vague hypotheses.</p>
+
+<p>It may be said, for one thing, that during sleep the nervous substance
+as a whole is less irritable than during waking hours. That is to say, a
+greater amount of stimulus is needed to produce any conscious
+result.<a name="FNanchor_76_76" id="FNanchor_76_76"></a><a href="#Footnote_76_76" class="fnanchor">[76]</a> This appears plainly enough in the case of the peripheral
+sense-organs. Although these are not, as it is often supposed, wholly
+inactive during sleep, they certainly require a more potent external
+stimulus to rouse them to action. And what applies to the peripheral
+regions applies to the centres. In truth, it is clearly impossible to
+distinguish between the diminished irritability of the peripheral and
+that of the central structures.</p>
+
+<p>At first sight it seems contradictory to the above to say that stimuli
+which have little effect on the centres of consciousness during waking
+life produce an appreciable result in sleep. Nevertheless, it will be
+found that this is the case. Thus organic processes which scarcely make
+themselves known to the mind in a waking state, may be shown to be the
+originators of many of our dreams. This fact can only be explained on
+the physical side by saying that the special cerebral<span class='pagenum'><a name="Page_136" id="Page_136">[Pg 136]</a></span> activities
+engaged in an act of attention are greatly liberated during sleep by the
+comparative quiescence of the external senses. These activities, by
+co-operating with the faint results of the stimuli coming from the
+internal organs, serve very materially to increase their effect.</p>
+
+<p>Finally, it is to be observed that, while the centres thus respond with
+diminished energy to peripheral stimuli, external and internal, they
+undergo a direct, or "automatic," mode of excitation, being roused into
+activity independently of an incoming nervous impulse. This automatic
+stimulation has been plausibly referred to the action of the products of
+decomposition accumulating in the cerebral blood-vessels.<a name="FNanchor_77_77" id="FNanchor_77_77"></a><a href="#Footnote_77_77" class="fnanchor">[77]</a> It is
+possible that there is something in the nature of this stimulation to
+account for the force and vividness of its conscious results, that is to
+say, of dreams.</p>
+
+
+<p class='center'><i>The Dream State.</i></p>
+
+<p>Let us now turn to the psychic side of these conditions, that is to say,
+to the general character of the mental states known as dreams. It is
+plain that the closing of the avenues of the external senses, which is
+the accompaniment of sleep, will make an immense difference in the
+mental events of the time. Instead of drawing its knowledge from
+without, noting its bearings in relation to the environment, the mind
+will now be given over to the play of internal imagination. The activity
+of fancy will, it is plain, be unrestricted by collision with external
+fact. The internal mental life will expand in free picturesque
+movement.<span class='pagenum'><a name="Page_137" id="Page_137">[Pg 137]</a></span></p>
+
+<p>To say that in sleep the mind is given over to its own imaginings, is to
+say that the mental life in these circumstances will reflect the
+individual temperament and mental history. For the play of imagination
+at any time follows the lines of our past experience more closely than
+would at first appear, and being coloured with emotion, will reflect the
+predominant emotional impulses of the individual mind. Hence the saying
+of Heraclitus, that, while in waking we all have a common world, in
+sleep we have each a world of our own.</p>
+
+<p>This play of imagination in sleep is furthered by the peculiar attitude
+of attention. When asleep the voluntary guidance of attention ceases;
+its direction is to a large extent determined by the contents of the
+mind at the moment. Instead of holding the images and ideas, and
+combining them according to some rational end, the attention relaxes its
+energies and succumbs to the force of imagination. And thus, in sleep,
+just as in the condition of reverie or day-dreaming, there is an
+abandonment of the fancy to its own wild ways.</p>
+
+<p>It follows that the dream-state will not appear to the mind as one of
+fancy, but as one of actual perception, and of contact with present
+reality. Dreams are clearly illusory, and, unlike the illusions of
+waking life, are complete and persistent.<a name="FNanchor_78_78" id="FNanchor_78_78"></a><a href="#Footnote_78_78" class="fnanchor">[78]</a> And the reason of this
+ought now to be clear. First of all, the mind during sleep wants what M.
+Taine calls the corrective of a pre<span class='pagenum'><a name="Page_138" id="Page_138">[Pg 138]</a></span>sent sensation. When awake under
+ordinary circumstances, any momentary illusion is at once set right by a
+new act of orientation. The superior vividness of the external
+impression cannot leave us in any doubt, when calm and self-possessed,
+whether our mental images answer to present realities or not. On the
+other hand, when asleep, this reference to a fixed objective standard is
+clearly impossible. Secondly, we may fairly argue that the mental images
+of sleep approximate in character to external impressions. This they do
+to some extent in point of intensity, for, in spite of the diminished
+excitability of the centres, the mode of stimulation which occurs in
+sleep may, as I have hinted, involve an energetic cerebral action. And,
+however this be, it is plain that the image will gain a preternatural
+force through the greatly narrowed range of attention. When the mind of
+the sleeper is wholly possessed by an image or group of images, and the
+attention kept tied down to these, there is a maximum reinforcement of
+the images. But this is not all. When the attention is thus held captive
+by the image, it approximates in character to an external impression in
+another way. In our waking state, when our powers of volition are
+intact, the external impression is characterized by its fixity or its
+obdurate resistance to our wishes. On the other hand, the mental image
+is fluent, accommodating, and disappears and reappears according to the
+direction of our volitions. In sleep, through the suspension of the
+higher voluntary power of attention, the mental image seems to lord it
+over our minds just as the actual impression of waking life.<span class='pagenum'><a name="Page_139" id="Page_139">[Pg 139]</a></span></p>
+
+<p>This much may suffice, perhaps, by way of a general description of the
+sleeping and dreaming state. Other points will make themselves known
+after we have studied the contents and structure of dreams in detail.</p>
+
+<p>Dreams are commonly classified (<i>e.g.</i> by Wundt) with hallucinations,
+and this rightly, since, as their common appellation of "vision"
+suggests, they are for the most part the semblance of percepts in the
+absence of external impressions. At the same time, recent research goes
+to show that in many dreams something answering to the "external
+impression" in waking perception is the starting-point. Consequently, in
+order to be as accurate as possible, I shall divide dreams into
+illusions (in the narrow sense) and hallucinations.</p>
+
+
+<p class='center'><i>Dream-Illusions.</i></p>
+
+<p>By dream-illusions I mean those dreams which set out from some
+peripheral nervous stimulation, internal or external. That the organic
+processes of digestion, respiration, etc., act as stimuli to the centres
+in sleep is well known. Thus, David Hartley assigns as the second great
+source of dreams "states of the body."<a name="FNanchor_79_79" id="FNanchor_79_79"></a><a href="#Footnote_79_79" class="fnanchor">[79]</a> But it is not so well known
+to what an extent our dreams may be influenced by stimuli acting on the
+exterior sense-organs. Let us first glance at the action of such
+external stimuli.</p>
+
+
+<p class='center'><i>Action of External Stimuli.</i></p>
+
+<p>During sleep the eyes are closed, and consequently the action of
+external light on the retina impeded.<span class='pagenum'><a name="Page_140" id="Page_140">[Pg 140]</a></span> Yet it is found that even under
+these circumstances any very bright light suddenly introduced is capable
+of stimulating the optic fibres, and of affecting consciousness. The
+most common form of this is the effect of bright moonlight, and of the
+early sun's rays. Krauss tells a funny story of his having once, when
+twenty-six years old, caught himself, on waking, in the act of
+stretching out his arms towards what his dream-fancy had pictured as the
+image of his mistress. When fully awake, this image resolved itself into
+the full moon.<a name="FNanchor_80_80" id="FNanchor_80_80"></a><a href="#Footnote_80_80" class="fnanchor">[80]</a> It is not improbable, as Radestock remarks, that the
+rays of the sun or moon are answerable for many of the dreams of
+celestial glory which persons of a highly religious temperament are said
+to experience.</p>
+
+<p>External sounds, when not sufficient to rouse the sleeper, easily
+incorporate themselves into his dreams. The ticking of a watch, the
+stroke of a clock, the hum of an insect, the song of a bird, the patter
+of rain, are common stimuli to the dream-phantasy. M. Alf. Maury tells
+us, in his interesting account of the series of experiments to which he
+submitted himself in order to ascertain the result of external
+stimulation on the mind during sleep, that when a pair of tweezers was
+made to vibrate near his ear, he dreamt of bells, the tocsin, and the
+events of June, 1848.<a name="FNanchor_81_81" id="FNanchor_81_81"></a><a href="#Footnote_81_81" class="fnanchor">[81]</a> Most of us, probably, have gone through the
+experience of impolitely falling asleep when some one was reading to us,
+and of having dream-images suggested by the sounds that were still
+indistinctly heard. Scherner gives an amusing case of a youth who was
+permitted to<span class='pagenum'><a name="Page_141" id="Page_141">[Pg 141]</a></span> whisper his name into the ear of his obdurate mistress,
+the consequence of which was that the lady contracted a habit of
+dreaming about him, which led to a felicitous change of feeling on her
+part.<a name="FNanchor_82_82" id="FNanchor_82_82"></a><a href="#Footnote_82_82" class="fnanchor">[82]</a></p>
+
+<p>The two lower senses, smell and taste, seem to play a less-important
+part in the production of dream-illusions. Radestock says that the odour
+of flowers in a room easily leads to visual images of hot-houses,
+perfumery shops, and so on; and it is probable that the contents of the
+mouth may occasionally act as a stimulus to the organ of taste, and so
+give rise to corresponding dreams. As Radestock observes, these lower
+sensations do not commonly make known their quality to the sleeper's
+mind. They become transformed at once into visual, instead of into
+olfactory or gustatory percepts. That is to say, the dreamer does not
+imagine himself smelling or tasting, but seeing an object.</p>
+
+<p>The contact of objects with the tactual organ is one of the best
+recognized causes of dreams. M. Maury found that when his lips were
+tickled, his dream-fancy interpreted the impression as of a pitch
+plaster being torn off his face. An unusual pressure on any part of the
+body, as, for example, from contact with a fellow-sleeper, is known to
+give rise to a well-marked variety of dream. Our own limbs may even
+appear as foreign bodies to our dream-imagination, when through pressure
+they become partly paralyzed. Thus, on one occasion, I awoke from a
+miserable dream, in which I felt sure I was grasping somebody's hand in<span class='pagenum'><a name="Page_142" id="Page_142">[Pg 142]</a></span>
+bed, and I was racked by terrifying conjectures as to who it might be.
+When fully awake, I discovered that I had been lying on my right side,
+and clasping the wrist of the right arm (which had been rendered
+insensible by the pressure of the body) with the left hand.</p>
+
+<p>In close connection with these stimuli of pressure are those of muscular
+movement, whether unimpeded or impeded. We need not enter into the
+difficult question how far the "muscular sense" is connected with the
+activity of the motor nerves, and how far with sensory fibres attached
+to the muscular or the adjacent tissues. Suffice it to say that an
+actual movement, a resistance to an attempted movement, or a mere
+disposition to movement, whether consequent on a surplus of motor energy
+or on a sensation of discomfort or fatigue in the part to be moved,
+somehow or other makes itself known to our minds, even when we are
+deprived of the assistance of vision. And these feelings of movement,
+impeded or unimpeded, are common initial impulses in our
+dream-experiences. It is quite a mistake to suppose that dreams are
+built up out of the purely passive sensations of sight and hearing. A
+close observation will show that in nearly every dream we imagine
+ourselves either moving among the objects we perceive or striving to
+move when some weighty obstacle obstructs us. All of us are familiar
+with the common forms of nightmare, in which we strive hopelessly to
+flee from some menacing evil, and this dream-experience, it may be
+presumed, frequently comes from a feeling of strain in the muscles, due
+to an awkward disposition of the limbs during sleep. The common
+dream-illusion of falling down a vast abyss is plausibly<span class='pagenum'><a name="Page_143" id="Page_143">[Pg 143]</a></span> referred by
+Wundt to an involuntary extension of the foot of the sleeper.</p>
+
+
+<p class='center'><i>Action of Internal Stimuli.</i></p>
+
+<p>Let us now pass from the action of stimuli lying outside the organism,
+to that of stimuli lying within the peripheral regions of the
+sense-organs. I have already spoken of the influence of subjective
+sensations of sight, hearing, etc., on the illusions of waking life, and
+it is now to be added that these sensations play an important part in
+our dream-life. Johannes M&uuml;ller lays great prominence on the part taken
+by ocular spectra in the production of dreams. As he observes, the
+apparent rays of light, light-patches, mists of light, and so on, due to
+changes of blood-pressure in the retina, only manifest themselves
+clearly when the eyes are closed and the more powerful effect of the
+external stimulus cut off. These subjective spectra come into prominence
+in the sleepy condition, giving rise to what M. Maury calls
+"hallucinations hypnagogiques," and which he regards (after Gruithuisen)
+as the chaos out of which the dream-cosmos is evolved.<a name="FNanchor_83_83" id="FNanchor_83_83"></a><a href="#Footnote_83_83" class="fnanchor">[83]</a> They are
+pretty certainly the starting-point in those picturesque dreams in which
+figure a number of bright objects, such as beautiful birds, butterflies,
+flowers, or angels.</p>
+
+<p>That the visual images of our sleep do often involve the peripheral
+regions of the organ of sight, seems to be proved by the singular fact
+that they sometimes persist after waking. Spinoza and Jean Paul Richter<span class='pagenum'><a name="Page_144" id="Page_144">[Pg 144]</a></span>
+both experienced this survival of dream-images. Still more pertinent is
+the fact that the effects of retinal fatigue are producible by
+dream-images. The physiologist Gruithuisen had a dream, in which the
+principal feature was a violet flame, and which left behind it, <i>after
+waking</i>, for an appreciable duration, a complementary image of a yellow
+spot.<a name="FNanchor_84_84" id="FNanchor_84_84"></a><a href="#Footnote_84_84" class="fnanchor">[84]</a></p>
+
+<p>Subjective auditory sensations appear to be much less frequent causes of
+dream-illusions than corresponding visual sensations. Yet the rushing,
+roaring sound caused by the circulation of the blood in the ear is,
+probably, a not uncommon starting-point in dreams. With respect to
+subjective sensations of smell and taste, there is little to be said. On
+the other hand, subjective sensations due to varying conditions in the
+skin are a very frequent exciting cause of dreams. Variations in the
+state of tension of the skin, brought about by alteration of position,
+changes in the character of the circulation, the irradiation of heat to
+the skin or the loss of the same, chemical changes,&mdash;these are known to
+give rise to a number of familiar sensations, including those of
+tickling, itching, burning, creeping, and so on; and the effects of
+these sensations are distinctly traceable in our dreams. For example,
+the exposure of a part of the body through a loss of the bed-clothes is
+a frequent excitant of distressing dreams. A cold foot suggests that the
+sleeper is walking over snow or ice. On the other hand, if the cold foot
+happens to touch a warm part of the body, the<span class='pagenum'><a name="Page_145" id="Page_145">[Pg 145]</a></span> dream-fancy constructs
+images of walking on burning lava, and so on.</p>
+
+<p>These sensations of the skin naturally conduct us to the organic
+sensations as a whole; that is to say, the feelings connected with the
+varying condition of the bodily organs. These include the feelings which
+arise in connection with the processes of digestion, respiration, and
+circulation, and the condition of various organs according to their
+state of nutrition, etc. During our waking life these organic feelings
+coalesce for the most part, forming as the "vital sense" an obscure
+background for our clear discriminative consciousness, and only come
+forward into this region when very exceptional in character, as when
+respiration or digestion is impeded, or when we make a special effort of
+attention to single them out.<a name="FNanchor_85_85" id="FNanchor_85_85"></a><a href="#Footnote_85_85" class="fnanchor">[85]</a> When we are asleep, however, and the
+avenues of external perception are closed, they assume greater
+prominence and distinctness. The centres, no longer called upon to react
+on stimuli coming from without the organism, are free to react on
+stimuli coming from its hidden recesses. So important a part, indeed, do
+these organic feelings take in the dream-drama, that some writers are
+disposed to regard them as the great, if not the exclusive, cause of
+dreams. Thus, Schopenhauer held that the excitants of dreams are
+impressions received from the internal regions of the organism through
+the sympathetic nervous system.<a name="FNanchor_86_86" id="FNanchor_86_86"></a><a href="#Footnote_86_86" class="fnanchor">[86]</a><span class='pagenum'><a name="Page_146" id="Page_146">[Pg 146]</a></span></p>
+
+<p>It is hardly necessary, perhaps, to give many illustrations of the
+effect of such organic sensations on our dreams. Among the most common
+provocatives of dreams are sensations connected with a difficulty in
+breathing, due to the closeness of the air or to the pressure of the
+bed-clothes on the mouth. J. B&ouml;rner investigated the influence of these
+circumstances by covering with the bed-clothes the mouth and a part of
+the nostrils of persons who were sound asleep. This was followed by a
+protraction of the act of breathing, a reddening of the face, efforts to
+throw off the clothes, etc. On being roused, the sleeper testified that
+he had experienced a nightmare, in which a horrid animal seemed to be
+weighing him down.<a name="FNanchor_87_87" id="FNanchor_87_87"></a><a href="#Footnote_87_87" class="fnanchor">[87]</a> Irregularity of the heart's action is also a
+frequent cause of dreams. It is not improbable that the familiar
+dream-experience of flying arises from disturbances of the respiratory
+and circulatory movements.</p>
+
+<p>Again, the effects of indigestion, and more particularly stomachic
+derangement, on dreams are too well known to require illustration. It
+may be enough to allude to the famous dream which Hood traces to an
+excessive indulgence at supper. It is known that the varying condition
+of the organs of secretion influences our dream-fancy in a number of
+ways.</p>
+
+<p>Finally, it is to be observed that an injury done to any part of the
+organism is apt to give rise to appro<span class='pagenum'><a name="Page_147" id="Page_147">[Pg 147]</a></span>priate dream-images. In this way,
+very slight disturbances which would hardly affect waking consciousness
+may make themselves felt during sleep. Thus, for example, an incipient
+toothache has been known to suggest that the teeth are being
+extracted.<a name="FNanchor_88_88" id="FNanchor_88_88"></a><a href="#Footnote_88_88" class="fnanchor">[88]</a></p>
+
+<p>It is worth observing that the interpretation of these various orders of
+sensations by the imagination of the dreamer takes very different forms
+according to the person's character, previous experience, ruling
+emotions, and so on. This is what is meant by saying that during sleep
+every man has a world of his own, whereas, when awake, he shares in the
+common world of perception.</p>
+
+
+<p class='center'><i>Dream-Exaggeration.</i></p>
+
+<p>It is to be noticed, further, that this interpretation of sensation
+during sleep is uniformly a process of exaggeration.<a name="FNanchor_89_89" id="FNanchor_89_89"></a><a href="#Footnote_89_89" class="fnanchor">[89]</a> The exciting
+causes of the feeling of discomfort, for example, are always absurdly
+magnified. The reason of this seems to be that, owing to the condition
+of the mind during sleep, the nature of the sensation is not clearly
+recognizable. Even in the case of familiar external impressions, such as
+the sound of the striking of a clock, there appears to be wanting that
+simple process of reaction by which, in a waking condition of the
+attention, a sense-impression is instantly discriminated and classed. In
+sleep, as in the artifi<span class='pagenum'><a name="Page_148" id="Page_148">[Pg 148]</a></span>cially induced hypnotic condition, the slighter
+differences of quality among sensations are not clearly recognized. The
+activity of the higher centres, which are concerned in the finer
+processes of discrimination and classification, being greatly reduced,
+the impression may be said to come before consciousness as something
+novel and unfamiliar. And just as we saw that in waking life novel
+sensations agitate the mind, and so lead to an exaggerated mode of
+interpretation; so here we see that what is unfamiliar disturbs the
+mind, rendering it incapable of calm attention and just interpretation.</p>
+
+<p>This failure to recognize the real nature of an impression is seen most
+conspicuously in the case of the organic sensations. As I have remarked,
+these constitute for the most part, in waking life, an undiscriminated
+mass of obscure feeling, of which we are only conscious as the mental
+tone of the hour. And in the few instances in which we do attend to them
+separately, whether through their exceptional intensity or in
+consequence of an extraordinary effort of discriminative attention, we
+can only be said to perceive them, that is, recognize their local
+origin, very vaguely. Hence, when asleep, these sensations get very
+oddly misinterpreted.</p>
+
+<p>The localization of a bodily sensation in waking life means the
+combination of a tactual and a visual image with the sensation. Thus, my
+recognition of a twinge of toothache as coming from a certain tooth,
+involves representations of the active and passive sensations which
+touching and looking at the tooth would yield me. That is to say, the
+feeling instantly calls up a compound mental image exactly answering to
+a<span class='pagenum'><a name="Page_149" id="Page_149">[Pg 149]</a></span> visual percept. This holds good in dream-interpretation too; the
+interpretation is effected by means of a visual image. But since the
+feeling is only very vaguely recognized, this visual image does not
+answer to the bodily part concerned. Instead of this, the fancy of the
+dreamer constructs some visual image which bears a vague resemblance to
+the proper one, and is generally, if not always, an exaggeration of this
+in point of extensive magnitude, etc. For example, a sensation arising
+from pressure on the bladder, being dimly connected with the presence of
+a fluid, calls up an image of a flood, and so on.</p>
+
+<p>This mode of dream-interpretation has by some writers been erected into
+the typical mode, under the name of dream-symbolism. Thus Scherner, in
+his interesting though somewhat fanciful work, <i>Das Leben des Traumes</i>,
+contends that the various regions of the body regularly disclose
+themselves to the dream-fancy under the symbol of a building or group of
+buildings; a pain in the head calling up, for example, the image of
+spiders on the ceiling, intestinal sensations exciting an image of a
+narrow alley, and so on. Such theories are clearly an exaggeration of
+the fact that the localization of our bodily sensations during sleep is
+necessarily imperfect.<a name="FNanchor_90_90" id="FNanchor_90_90"></a><a href="#Footnote_90_90" class="fnanchor">[90]</a></p>
+
+<p>In many cases the image called up bears on its objective side no
+discoverable resemblance to that of the bodily region or the exciting
+cause of the sensation. Here the explanation must be looked for in the
+subjective side of the sensation and mental image, that is to say, in
+their emotional quality, as pleasurable or<span class='pagenum'><a name="Page_150" id="Page_150">[Pg 150]</a></span> painful, distressing,
+quieting, etc. It is to be observed, indeed, that in natural sleep, as
+in the condition known as hypnotism, while differences of specific
+quality in the sense-impressions are lost, the broad difference of the
+pleasurable and the painful is never lost. It is, in fact, the
+subjective emotional side of the sensation that uniformly forces itself
+into consciousness. This being so, it follows that, speaking generally,
+the sensations of sleep, both external and internal, or organic, will be
+interpreted by what G.H. Lewes has called "an analogy of feeling;" that
+is to say, by means of a mental image having some kindred emotional
+character or colouring.</p>
+
+<p>Now, the analogy between the higher emotional and the bodily states is a
+very close one. A sensation of obstruction in breathing has its exact
+analogue in a state of mental embarrassment, a sensation of itching its
+counterpart in mental impatience, and so on. And since these emotional
+experiences are deeper and fuller than the sensations, the tendency to
+exaggerate the nature and causes of these last would naturally lead to
+an interpretation of them by help of these experiences. In addition to
+this, the predominance of visual imagery in sleep would aid this
+transformation of a bodily sensation into an emotional experience, since
+visual perceptions have, as their accompaniments of pleasure and pain,
+not sensations, but emotions.<a name="FNanchor_91_91" id="FNanchor_91_91"></a><a href="#Footnote_91_91" class="fnanchor">[91]</a></p>
+<p><span class='pagenum'><a name="Page_151" id="Page_151">[Pg 151]</a></span></p>
+<p>Since in this vague interpretation of bodily sensation the actual
+impression is obscured, and not taken up as an integral part into the
+percept, it is evident that we cannot, strictly speaking, call the
+process an imitation of an act of perception, that is to say, an
+illusion. And since, moreover, the visual image by which the sensation
+is thus displaced appears as a present object, it would, of course, be
+allowable to speak of this as an hallucination. This substitution of a
+more or less analogous visual image for that appropriate to the
+sensation forms, indeed, a transition from dream-illusion, properly so
+called, to dream-hallucination.</p>
+
+
+<p class='center'><i>Dream-Hallucinations.</i></p>
+
+<p>On the physical side, these hallucinations answer to cerebral
+excitations which are central or automatic, not depending on movements
+transmitted from the periphery of the nervous system. Of these
+stimulations some appear to be direct, and due to unknown influences
+exerted by the state of nutrition of the cerebral elements, or the
+action of the contents of the blood-vessels on these elements.</p>
+
+
+<p class='center'><i>Effects of Direct Central Stimulation.</i></p>
+
+<p>That such action does prompt a large number of dream-images may be
+regarded as fairly certain. First of all, it seems impossible to account
+for all the images of dream-fancy as secondary phenomena connected by
+links of association with the foregoing classes of sensation. However
+fine and invisible many of the threads which hold together our ideas may
+be, they will hardly<span class='pagenum'><a name="Page_152" id="Page_152">[Pg 152]</a></span> explain the profusion and picturesque variety of
+dream-imagery. Secondly, we are able in certain cases to infer with a
+fair amount of certainty that a dream-image is due to such central
+stimulation. The common occurrence that we dream of the more stirring
+events, the anxieties and enjoyments of the preceding day, appears to
+show that when the cerebral elements are predisposed to a certain kind
+of activity, as they are after having been engaged for some time in this
+particular work, they are liable to be excited by some stimulus brought
+directly to bear on them during sleep. And if this is so, it is not
+improbable that many of the apparently forgotten images of persons and
+places which return with such vividness in dreams are excited by a mode
+of stimulation which is for the greater part confined to sleep. I say
+"for the greater part," because even in our indolent, listless moments
+of waking existence such seemingly forgotten ideas sometimes return as
+though by a spontaneous movement of their own and by no discoverable
+play of association.</p>
+
+<p>It may be well to add that this immediate revival of impressions
+previously received by the brain includes not only the actual
+perceptions of waking life, but also the ideas derived from others, the
+ideal fancies supplied by works of fiction, and even the images which
+our unaided waking fancy is wont to shape for itself. Our daily
+conjectures as to the future, the communications to us by others of
+their thoughts, hopes, and fears,&mdash;these give rise to numberless vague
+fugitive images, any one of which may become distinctly revived in
+sleep.<a name="FNanchor_92_92" id="FNanchor_92_92"></a><a href="#Footnote_92_92" class="fnanchor">[92]</a>This throws light on the curious fact that we often dream of
+experiences and events quite unlike those of our individual life. Thus,
+for example, the common construction by the dream-fancy of the
+experience of flight in mid-air, and the creation of those weird forms
+which the terror of a nightmare is wont to bring in its train, seem to
+point to the past action of waking fancy. To imagine one's self flying
+when looking at a bird is probably a common action with all persons, at
+least in their earlier years, and images of preternaturally horrible
+beings are apt to be supplied to most of us some time during life by
+nurses or by books.</p>
+<p><span class='pagenum'><a name="Page_153" id="Page_153">[Pg 153]</a></span></p>
+
+<p class='center'><i>Indirect Central Stimulation.</i></p>
+
+<p>Besides these direct central stimulations, there are others which, in
+contradistinction, may be called indirect, depending on some previous
+excitation. These are, no doubt, the conditions of a very large number
+of our dream-images. There must, of course, be some primary cerebral
+excitation, whether that of a present peripheral stimulation, or that
+which has been termed central and spontaneous; but when once this first
+link of the imaginative chain is supplied, other links may be added in
+large numbers through the operation of the forces of association. One
+may, indeed, safely say that the large proportion of the contents of
+every dream arise in this way.<span class='pagenum'><a name="Page_154" id="Page_154">[Pg 154]</a></span></p>
+
+<p>The very simplest type of dream excited by a present sensation contains
+these elements. To take an example, I once dreamt, as a consequence of
+the loud barking of a dog, that a dog approached me when lying down, and
+began to lick my face. Here the play of the associative forces was
+apparent: a mere sensation of sound called up the appropriate visual
+image, this again the representation of a characteristic action, and so
+on. So it is with the dreams whose first impulse is some central or
+spontaneous excitation. A momentary sight of a face or even the mention
+of a name during the preceding day may give the start to dream-activity;
+but all subsequent members of the series of images owe their revival to
+a tension, so to speak, in the fine threads which bind together, in so
+complicated a way, our impressions and ideas.</p>
+
+<p>Among the psychic accompaniments of these central excitations visual
+images, as already hinted, fill the most conspicuous place. Even
+auditory images, though by no means absent, are much less numerous than
+visual. Indeed, when there are the conditions for the former, it
+sometimes happens that the auditory effect transforms itself into a
+visual effect. An illustration of this occurred in my own experience.
+Trying to fall asleep by means of the well-known device of counting, I
+suddenly found myself losing my hold on the faint auditory effects, my
+imagination transforming them into a visual spectacle, under the form of
+a path of light stretching away from me, in which the numbers appeared
+under the grotesque form of visible objects, tumbling along in glorious
+confusion.</p>
+
+<p>Next to these visual phantasms, certain motor<span class='pagenum'><a name="Page_155" id="Page_155">[Pg 155]</a></span> hallucinations seem to be
+most prominent in dreams. By a motor hallucination, I mean the illusion
+that we are actually moving when there is no peripheral excitation of
+the motor organ. Just as the centres concerned in passive sensation are
+susceptible of central stimulation, so are the centres concerned in
+muscular sensation. A mere impulse in the centres of motor innervation
+(if we assume these to be the central seat of the muscular feelings) may
+suffice to give rise to a complete representation of a fully executed
+movement. And thus in our sleep we seem to walk, ride, float, or fly.</p>
+
+<p>The most common form of motor hallucination is probably the vocal. In
+the social encounters which make up so much of our sleep-experience, we
+are wont to be very talkative. Now, perhaps, we find ourselves zealously
+advocating some cause, now very fierce in denunciation, now very amusing
+in witty repartee, and so on. This imagination of ourselves as speaking,
+as distinguished from that of hearing others talking, must, it is clear,
+involve the excitation of the structures engaged in the production of
+the muscular feelings which accompany vocal action, as much as, if not
+more than, the auditory centres. And the frequency of this kind of
+dream-experience may be explained, like that of visual imagery, by the
+habits of waking life. The speech impulse is one of the most deeply
+rooted of all our impulses, and one which has been most frequently
+exercised in waking life.<span class='pagenum'><a name="Page_156" id="Page_156">[Pg 156]</a></span></p>
+
+<p class='center'><i>Combination of Dream-Elements.</i></p>
+
+<p>It is commonly said that dreams are a grotesque dissolution of all
+order, a very chaos and whirl of images without any discoverable
+connection. On the other hand, a few writers claim for the mind in sleep
+a power of arranging and grouping its incongruous elements in definite
+and even life-like pictures. Each of these views is correct within
+certain limits; that is to say, there are dreams in which the strangest
+disorder seems to prevail, and others in which one detects the action of
+a central control. Yet, speaking generally, sequences of dream-images
+will be found to be determined by certain circumstances and laws, and so
+far not to be haphazard or wholly chaotic. We have now to inquire into
+the laws of these successions; and, first of all, we may ask how far the
+known laws of association, together with the peculiar conditions of the
+sleeping state, are able to account for the various modes of
+dream-combination. We have already regarded mental association as
+furnishing a large additional store of dream-imagery; we have now to
+consider it as explaining the sequences and concatenations of our
+dream-elements.</p>
+
+
+<p class='center'><i>Incoherence of Dreams.</i></p>
+
+<p>First of all, then, let us look at the chaotic and apparently lawless
+side of dreaming, and see whether any clue is discoverable to the centre
+of this labyrinth. In the case of all the less elaborately ordered
+dreams, in which sights and sounds appear to succeed one another in the
+wildest dance (which class of dreams<span class='pagenum'><a name="Page_157" id="Page_157">[Pg 157]</a></span> probably belongs to the deeper
+stages of sleep), the mind may with certainty be regarded as purely
+passive, and the mode of sequence may be referred to the action of
+association complicated by the ever-recurring introduction of new
+initial impulses, both peripheral and central. These are the dreams in
+which we are conscious of being perfectly passive, either as spectators
+of a strange pageant, or as borne away by some apparently extraneous
+force through a series of the most diverse experiences. The flux of
+images in these dreams is very much the same as that in certain waking
+conditions, in which we relax attention, both external and internal, and
+yield ourselves wholly to the spontaneous play of memory and fancy.</p>
+
+<p>It is plain at a glance that the simultaneous concurrence of wholly
+disconnected initial impulses will serve to impress a measure of
+disconnectedness on our dream-images. From widely remote parts of the
+organism there come impressions which excite each its peculiar visual or
+other image according as its local origin or its emotional tone is the
+more distinctly present to consciousness. Now it is a subjective ocular
+sensation suggesting a bouquet of lovely flowers, and close on its heels
+comes an impression from the organs of digestion suggesting all manner
+of obstacles, and so our dream-fancy plunges from a vision of flowers to
+one of dreadful demons.</p>
+
+<p>Let us now look at the way in which the laws of association working on
+the incongruous elements thus cast up into our dream-consciousness, will
+serve to give a yet greater appearance of disorder and confusion to our
+dream-combinations. According to these laws,<span class='pagenum'><a name="Page_158" id="Page_158">[Pg 158]</a></span> any idea may, under
+certain circumstances, call up another, if the corresponding impressions
+have only once occurred together, or if the ideas have any degree of
+resemblance, or, finally, if only they stand in marked contrast with one
+another. Any accidental coincidence of events, such as meeting a person
+at a particular foreign resort, and any insignificant resemblance
+between objects, sounds, etc., may thus supply a path, so to speak, from
+fact to dream-fancy.</p>
+
+<p>In our waking states these innumerable paths of association are
+practically closed by the supreme energy of the coherent groups of
+impressions furnished us from the world without through our organs of
+sense, and also by the volitional control of internal thought in
+obedience to the pressure of practical needs and desires. In dream-life
+both of these influences are withdrawn, so that delicate threads of
+association, which have no chance of exerting their pull, so to speak,
+in our waking states, now make known their hidden force. Little wonder,
+then, that the filaments which bind together these dream-successions
+should escape detection, since even in our waking thought we so often
+fail to see the connection which makes us pass in recollection from a
+name to a visible scene or perhaps to an emotional vibration.</p>
+
+<p>It is worth noting that the origin of an association is often to be
+looked for in one of those momentary half-conscious acts of waking
+imagination to which reference has already been made. A friend, for
+example, has been speaking to us of some common acquaintance, remarking
+on his poor health. The language calls up, vaguely, a visual
+representation of<span class='pagenum'><a name="Page_159" id="Page_159">[Pg 159]</a></span> the person sinking in health and dying. An
+association will thus be formed between this person and the idea of
+death. A night or two after, the image of this person somehow recurs to
+our dream-fancy, and we straightway dream that we are looking at his
+corpse, watching his funeral, and so on. The links of the chain which
+holds together these dream-images were really forged, in part, in our
+waking hours, though the process was so rapid as to escape our
+attention. It may be added, that in many cases where a juxtaposition of
+dream-images seems to have no basis in waking life, careful reflection
+will occasionally bring to light some actual conjunction of impressions
+so momentary as to have faded from our recollection.</p>
+
+<p>We must remember, further, how great an apparent disorder will invade
+our imaginative dream-life when the binding force of resemblance has
+unchecked play. In waking thought we have to connect things according to
+their essential resemblances, classifying objects and events for
+purposes of knowledge or action, according to their widest or their most
+important points of similarity. In sleep, on the contrary, the slightest
+touch of resemblance may engage the mind and affect the direction of
+fancy. In a sense we may be said, when dreaming, to discover mental
+affinities between impressions and feelings, including those subtle
+links of emotional analogy of which I have already spoken. This effect
+is well illustrated in a dream recorded by M. Maury, in which he passed
+from one set of images to another through some similarity of names, as
+that between <i>corps</i> and <i>cor</i>. Such a movement of fancy would, of
+course, be prevented in full waking conscious<span class='pagenum'><a name="Page_160" id="Page_160">[Pg 160]</a></span>ness by a predominant
+attention to the meaning of the sounds.</p>
+
+<p>It will be possible, I think, after a habit of analyzing one's dreams in
+the light of preceding experience has been formed, to discover in a good
+proportion of cases some hidden force of association which draws
+together the seemingly fortuitous concourse of our dream-atoms. That we
+should expect to do so in every case is unreasonable, since, owing to
+the numberless fine ramifications which belong to our familiar images,
+many of the paths of association followed by our dream-fancy cannot be
+afterwards retraced.</p>
+
+<p>To illustrate the odd way in which our images get tumbled together
+through the action of occult association forces, I will record a dream
+of my own. I fancied I was at the house of a distinguished literary
+acquaintance, at her usual reception hour. I expected the friends I was
+in the habit of meeting there. Instead of this, I saw a number of
+commonly dressed people having tea. My hostess came up and apologized
+for having asked me into this room. It was, she said, a tea-party which
+she prepared for poor people at sixpence a head. After puzzling over
+this dream, I came to the conclusion that the missing link was a verbal
+one. A lady who is a connection of my friend, and bears the same name,
+assists her sister in a large kind of benevolent scheme. I may add that
+I had not, so far as I could recollect, had occasion very recently to
+think of this benevolent friend, but I had been thinking of my literary
+friend in connection with her anticipated return to town.</p>
+
+<p>In thus seeking to trace, amid the superficial chaos<span class='pagenum'><a name="Page_161" id="Page_161">[Pg 161]</a></span> of dream-fancy,
+its hidden connections, I make no pretence to explain why in any given
+case these particular paths of association should be followed, and more
+particularly why a slender thread of association should exert a pull
+where a stronger cord fails to do so. To account for this, it would be
+necessary to call in the physiological hypothesis that among the nervous
+elements connected with a particular element, <i>a</i>, already excited,
+some, as <i>m</i> and <i>n</i>, are at the moment, owing to the state of their
+nutrition or their surrounding influences, more powerfully predisposed
+to activity than other elements, as <i>b</i> and <i>c</i>.</p>
+
+<p>The subject of association naturally conducts us to the second great
+problem in the theory of dreams&mdash;the explanation of the order in which
+the various images group themselves in all our more elaborate dreams.</p>
+
+
+<p class='center'><i>Coherence of Dreams.</i></p>
+
+<p>A fully developed dream is a complex of many distinct illusory
+sense-presentations: in this respect it differs from the illusions of
+normal waking life, which are for the most part single and isolated. And
+this complex of quasi-presentations appears somehow or other to fall
+together into one whole scene or series of events, which, though it may
+be very incongruous and absurdly impossible from a waking point of view,
+nevertheless makes a single object for the dreamer's internal vision,
+and has a certain degree of artistic unity. This plastic force, which
+selects and binds together our unconnected dream-images, has frequently
+been referred to as a mysterious spiritual faculty, under the name of
+"creative fancy." Thus Cudworth<span class='pagenum'><a name="Page_162" id="Page_162">[Pg 162]</a></span> remarks, in his <i>Treatise concerning
+Eternal and Immutable Morality</i>: "That dreams are many times begotten by
+the phantastical power of the soul itself ... is evident from the
+orderly connection and coherence of imaginations which many times are
+continued in a long chain or series." One may find a good deal of
+mystical writing on the nature and activity of this faculty, especially
+in German literature. The explanation of this element of organic unity
+in dreams is, it may be safely said, the crux in the science of dreams.
+That the laws of psychology help us to understand the sequences of
+dream-images, we have seen. What we have now to ask is whether these
+laws throw any light on the orderly grouping of the elements so brought
+up in consciousness in the form of a connected experience.</p>
+
+<p>It is to be remarked at the outset that a singular kind of unity is
+sometimes given to our dream-combinations by a total or partial
+coalescence of different images. The conditions of such coalescence have
+been referred to already.<a name="FNanchor_93_93" id="FNanchor_93_93"></a><a href="#Footnote_93_93" class="fnanchor">[93]</a> Simultaneous impressions or images will
+always tend to coalesce with a force which varies directly as the degree
+of their similarity. Sometimes this coalescence is instantaneous and not
+made known to consciousness. Thus, Radestock suggests that if the mind
+of the sleeper is simultaneously invaded by an unpleasant sensation
+arising out of some disturbance of the functions of the skin, and a
+subjective visual sensation, the resulting mental image may be a
+combination of the two, under the form of a caterpillar creeping over
+the bodily surface. And the<span class='pagenum'><a name="Page_163" id="Page_163">[Pg 163]</a></span> coalescence may even be prepared by
+sub-conscious operations of waking imagination. Thus, for example, I
+once spoke about the cheapness of hares to a member of my family, who
+somewhat grimly suggested that they were London cats. I did not dwell on
+the idea, but the following night I dreamt that I saw a big hybrid
+creature, half hare, half cat, sniffing about a cottage. As it stood on
+its hind legs and took a piece of food from a window-ledge, I became
+sure that it was a cat. Here it is plain that the cynical observation of
+my relative had, at the moment, partially excited an image of this
+feline hare. In some dreams, again, we may become aware of the process
+of coalescence, as when persons who at one moment were seen to be
+distinct appear to our dream-fancy to run together in some third person.</p>
+
+<p>A very similar kind of unification takes place between sequent images
+under the form of transformation. When two images follow one another
+closely, and have anything in common, they readily assume the form of a
+transmutation. There is a sort of overlapping of the mental images, and
+so an appearance of continuity produced in some respects analogous to
+that which arises in the wheel-of-life (thaumatrope) class of
+sense-illusions. This would seem to account for the odd transformations
+of personality which not unfrequently occur in dreams, in which a person
+appears, by a kind of metempsychosis, to transfer his physical ego to
+another, and in which the dreamer's own bodily phantom plays similar
+freaks. And the same principle probably explains those dissolving-view
+effects which are so familiar an accompaniment of dream-scenery.<a name="FNanchor_94_94" id="FNanchor_94_94"></a><a href="#Footnote_94_94" class="fnanchor">[94]</a><span class='pagenum'><a name="Page_164" id="Page_164">[Pg 164]</a></span></p>
+
+<p>But passing from this exceptional kind of unity in dreams, let us
+inquire how the heterogeneous elements of our dream-fancy become ordered
+and arranged when they preserve their separate existence. If we look
+closely at the structure of our more finished dreams, we find that the
+appearance of harmony, connectedness, or order, may be given in one of
+two ways. There may, first of all, be a subjective harmony, the various
+images being held together by an emotional thread. Or there may,
+secondly, be an objective harmony, the parts of the dream, though
+answering to no particular experiences of waking life, bearing a certain
+resemblance to our habitual modes of experience. Let us inquire into the
+way in which each kind of order is brought about.</p>
+
+
+<p class='center'><i>Lyrical Element in Dreams.</i></p>
+
+<p>The only unity that belongs to many of our dreams is a subjective
+emotional unity. This is the basis of harmony in lyrical poetry, where
+the succession of images turns mainly on their emotional colouring.
+Thus, the images that float before the mind of the Poet Laureate, in his
+<i>In Memoriam</i>, clearly have their link of connection in their common
+emotional tone, rather than in any logical continuity. Dreaming has been
+likened to poetic composition, and certainly many of our dreams are
+built upon a groundwork of lyrical feeling. They might be marked off,
+perhaps, as our lyrical dreams.</p>
+
+<p>The way in which this emotional force acts in these cases has already
+been hinted at. We have seen that the analogy of feeling is a common
+link between dream-images. Now, if any shade of feeling becomes<span class='pagenum'><a name="Page_165" id="Page_165">[Pg 165]</a></span> fixed
+and dominant in the mind, it will tend to control all the images of the
+time, allowing certain congruous ones to enter, and excluding
+others.<a name="FNanchor_95_95" id="FNanchor_95_95"></a><a href="#Footnote_95_95" class="fnanchor">[95]</a> If, for example, a feeling of distress occupies the mind,
+distressing images will have the advantage in the struggle for existence
+which goes on in the world of mind as well as in that of matter. We may
+say that attention, which is here wholly a passive process, is
+controlled by the emotion of the time, and bent in the direction of
+congruent or harmonious images.</p>
+
+<p>Now, a ground-tone of feeling of a certain complexion, answering to the
+sum of sensations arising in connection with the different organic
+processes of the time, is a very frequent foundation of our
+dream-structure. So frequent is it, indeed, that one might almost say
+there is no dream in which it is not one great determining factor. The
+analysis of a very large number of dreams has convinced me that traces
+of this influence are discoverable in a great majority.</p>
+
+<p>I will give a simple illustration of this lyrical type of dream. A
+little girl of about four years and three-quarters went with her parents
+to Switzerland. On their way she was taken to the cathedral at
+Strasburg, and saw the celebrated clock strike, and the figures of the
+Apostles come out, etc. In Switzerland she stayed at Gimmelwald, near
+M&uuml;rren, opposite a fine mass of snowy mountains. One morning she told
+her father that she had had "such a lovely dream." She fancied she was
+on the snow-peaks with her nurse, and walked on to the sky. There came
+out of the sky "such<span class='pagenum'><a name="Page_166" id="Page_166">[Pg 166]</a></span> beautiful things," just like the figures of the
+clock. This vision of celestial things was clearly due to the fact that
+both the clock and the snow-peaks touching the blue sky had powerfully
+excited her imagination, filling her with much the same kind of emotion,
+namely, wonder, admiration, and longing to reach an inaccessible height.</p>
+
+<p>Our feelings commonly have a gradual rise and fall, and the organic
+sensations which so often constitute the emotional basis of our lyrical
+dreams generally have stages of increasing intensity. Moreover, such a
+persistent ground-feeling becomes reinforced by the images which it
+sustains in consciousness. Hence a certain <i>crescendo</i> character in our
+emotional dreams, or a gradual rise to some culminating point or climax.</p>
+
+<p>This phase of dream can be illustrated from the experience of the same
+little girl. When just five years old, she was staying at Hampstead,
+near a church which struck the hours somewhat loudly. One morning she
+related the following dream to her father (I use her own language). The
+biggest bells in the world were ringing; when this was over the earth
+and houses began to tumble to pieces; all the seas, rivers, and ponds
+flowed together, and covered all the land with black water, as deep as
+in the sea where the ships sail; people were drowned; she herself flew
+above the water, rising and falling, fearing to fall in; she then saw
+her mamma drowned, and at last flew home to tell her papa. The gradual
+increase of alarm and distress expressed in this dream, having its
+probable cause in the cumulative effect of the disturbing sound of the
+church bells, must be patent to all.<span class='pagenum'><a name="Page_167" id="Page_167">[Pg 167]</a></span></p>
+
+<p>The following rather comical dream illustrates quite as clearly the
+growth of a feeling of irritation and vexation, probably connected with
+the development of some slightly discomposing organic sensation. I
+dreamt I was unexpectedly called on to lecture to a class of young
+women, on Herder. I began hesitatingly, with some vague generalities
+about the Augustan age of German literature, referring to the three
+well-known names of Lessing, Schiller, and Goethe. Immediately my
+sister, who suddenly appeared in the class, took me up, and said she
+thought there was a fourth distinguished name belonging to this period.
+I was annoyed at the interruption, but said, with a feeling of triumph,
+"I suppose you mean Wieland?" and then appealed to the class whether
+there were not twenty persons who knew the names I had mentioned to one
+who knew Wieland's name. Then the class became generally disorderly. My
+feeling of embarrassment gained in depth. Finally, as a climax, several
+quite young girls, about ten years and less, came and joined the class.
+The dream broke off abruptly as I was in the act of taking these
+children to the wife of an old college tutor, to protest against their
+admission.</p>
+
+<p>It is worth noting, perhaps, that in this evolution of feeling in
+dreaming the quality of the emotion may vary within certain limits. One
+shade of feeling may be followed by another and kindred shade, so that
+the whole dream still preserves a degree, though a less obvious degree,
+of emotional unity. Thus, for example, a lady friend of mine once dreamt
+that she was in church, listening to a well-known novelist of the more
+earnest sort, preaching. A wounded soldier<span class='pagenum'><a name="Page_168" id="Page_168">[Pg 168]</a></span> was brought in to be shot,
+because he was mortally wounded, and had distinguished himself by his
+bravery. He was then shot, but not killed, and, rolling over in agony,
+exclaimed, "How long!" The development of an extreme emotion of horror
+out of the vague feeling of awe which is associated with a church, gives
+a curious interest to this dream.</p>
+
+
+<p class='center'><i>Verisimilitude in Dreams.</i></p>
+
+<p>I must not dwell longer on this emotional basis of dreams, but pass to
+the consideration of the second and objective kind of unity which
+characterizes many of our more elaborate dream-performances. In spite of
+all that is fitful and grotesque in dream-combination, it still
+preserves a distant resemblance to our actual experience. Though no
+dream reproduces a particular incident or chain of incidents in this
+experience, though the dream-fancy invariably transforms the particular
+objects, relations, and events of waking life, it still makes the order
+of our daily experience its prototype. It fashions its imaginary world
+on the model of the real. Thus, objects group themselves in space, and
+act on one another conformably to these perceived space-relations;
+events succeed one another in time, and are often seen to be connected;
+men act from more or less intelligible motives, and so on. In this way,
+though the dream-fancy sets at nought the particular relations of our
+experience, it respects the general and constant relations. How are we
+to account for this?</p>
+
+<p>It is said by certain philosophers that this superposition of the
+relations of space, time, causation,<span class='pagenum'><a name="Page_169" id="Page_169">[Pg 169]</a></span> etc., on the products of our
+dream-fancy is due to the fact that all experience arises by a synthesis
+of mental forms with the chaotic matter of sense-impressions. These
+philosophers allow, however, that all particular connections are
+determined by experience. Accordingly, what we have to do here is to
+inquire how far this scientific method of explaining mental connections
+by facts of experience will carry us. In other words, we have to ask
+what light can be thrown on these tendencies of dream-imagination by
+ascertained psychological laws, and more particularly by what are known
+as the laws of association.</p>
+
+<p>These laws tell us that of two mental phenomena which occur together,
+each will tend to recall the other whenever it happens to be revived. On
+the physiological side, this means that any two parts of the nervous
+structures which have acted together become in some way connected, so
+that when one part begins to work the other will tend to work also. But
+it is highly probable that a particular structure acts in a great many
+different ways. Thus, it may be stimulated by unlike modes of stimuli,
+or it may enter into very various connections with other structures.
+What will follow from this? One consequence would appear to be that
+there will be developed an organic connection between the two
+structures, of such a kind that whenever one is excited the other will
+be disposed to act somehow and anyhow, even when there is nothing in the
+present mode of activity of the first structure to determine the second
+to act in some one definite way, in other words, when this mode of
+activity is, roughly speaking, novel.<span class='pagenum'><a name="Page_170" id="Page_170">[Pg 170]</a></span></p>
+
+<p>Let me illustrate this effect in one of the simplest cases, that of the
+visual organ. If, when walking out on a dark night, a few points in my
+retina are suddenly stimulated by rays of light, and I recognize some
+luminous object in a corresponding direction, I am prepared to see
+something above and below, to the right and to the left of this object.
+Why is this? There may from the first have been a kind of innate
+understanding among contiguous optic fibres, predisposing them to such
+concerted action. But however this be, this disposition would seem to
+have been largely promoted by the fact that, throughout my experience,
+the stimulation of any retinal point has been connected with that of
+adjoining points, either simultaneously by some second object, or
+successively by the same object as the eye moves over it, or as the
+object itself moves across the field of vision.</p>
+
+<p>When, therefore, in sleep any part of the optic centres is excited in a
+particular way, and the images thus arising have their corresponding
+loci in space assigned to them, there will be a disposition to refer any
+other visual images which happen at the moment to arise in consciousness
+to adjacent parts of space. The character of these other images will be
+determined by other special conditions of the moment; their locality or
+position in space will be determined by this organic connection. We may,
+perhaps, call these tendencies to concerted action of some kind general
+associative dispositions.</p>
+
+<p>Just as there are such dispositions to united action among various parts
+of one organ of sense, so there may be among different organs, which are
+either con<span class='pagenum'><a name="Page_171" id="Page_171">[Pg 171]</a></span>nected originally in the infant organism, or have
+communications opened up by frequent coexcitation of the two. Such links
+there certainly are between the organs of taste and smell, and between
+the ear and the muscular system in general, and more particularly the
+vocal organ.<a name="FNanchor_96_96" id="FNanchor_96_96"></a><a href="#Footnote_96_96" class="fnanchor">[96]</a> A new odour often sets us asking how the object would
+taste, and a series of sounds commonly disposes us to movement of some
+kind or another. How far there may be finer threads of connection
+between other organs, such as the eye and the ear, which do not betray
+themselves amid the stronger forces of waking mental life, one cannot
+say. Whatever their number, it is plain that they will exert their
+influence within the comparatively narrow limits of dream-life, serving
+to impress a certain character on the images which happen to be called
+up by special circumstances, and giving to the combination a slight
+measure of congruity. Thus, if I were dreaming that I heard some lively
+music, and at the same time an image of a friend was anyhow excited, my
+dream-fancy might not improbably represent this person as performing a
+sequence of rhythmic movements, such as those of riding, dancing, etc.</p>
+
+<p>A narrower field for these general associative dispositions may be found
+in the tendency, on the reception of an impression of a given character,
+to look for a certain kind of second impression; though the exact nature
+of this is unknown. Thus, for example, the<span class='pagenum'><a name="Page_172" id="Page_172">[Pg 172]</a></span> form and colour of a new
+flower suggest a scent, and the perception of a human form is
+accompanied by a vague representation of vocal utterances. These general
+tendencies of association appear to me to be most potent influences in
+our dream-life. The many strange human forms which float before our
+dream-fancy are apt to talk, move, and behave like men and women in
+general, however little they resemble their actual prototypes, and
+however little individual consistency of character is preserved by each
+of them. Special conditions determine what they shall say or do; the
+general associative disposition accounts for their saying or doing
+something.</p>
+
+<p>We thus seem to find in the purely passive processes of association some
+ground for that degree of natural coherence and rational order which our
+more mature dreams commonly possess. These processes go far to explain,
+too, that odd mixture of rationality with improbability, of natural
+order and incongruity, which characterizes our dream-combinations.</p>
+
+
+<p class='center'><i>Rational Construction in Dreams.</i></p>
+
+<p>Nevertheless, I quite agree with Herr Volkelt that association, even in
+the most extended meaning, cannot explain all in the shaping of our
+dream-pictures. The "phantastical power" which Cudworth talks about
+clearly includes something besides. It is an erroneous supposition that
+when we are dreaming there is a complete suspension of the voluntary
+powers, and consequently an absence of all direction of the intellectual
+processes. This supposition, which has been maintained by numerous
+writers, from Dugald Stewart downwards,<span class='pagenum'><a name="Page_173" id="Page_173">[Pg 173]</a></span> seems to be based on the fact
+that we frequently find ourselves in dreams striving in vain to move the
+whole body or a limb. But this only shows, as M. Maury remarks in the
+work already referred to, that our volitions are frustrated through the
+inertia of our bodily organs, not that these volitions do not take
+place. In point of fact, the dreamer, not to speak of the somnambulist,
+is often conscious of voluntarily going through a series of actions.
+This exercise of volition is shown unmistakably in the well-known
+instances of extraordinary intellectual achievements in dreams, as
+Condillac's composition of a part of his <i>Cours d'&Eacute;tudes</i>. No one would
+maintain that a result of this kind was possible in the total absence of
+intellectual action carefully directed by the will. And something of
+this same control shows itself in all our more fully developed dreams.</p>
+
+<p>One manifestation of this voluntary activity in sleep is to be found in
+those efforts of attention which not unfrequently occur. I have remarked
+that, speaking roughly and in relation to the waking condition, the
+state of sleep is marked by a subjection of the powers of attention to
+the force of the mental images present to consciousness. Yet something
+resembling an exercise of voluntary attention sometimes happens in
+sleep. The intellectual feats just spoken of, unless, indeed, they are
+referred to some mysterious unconscious mental operations, clearly
+involve a measure of volitional guidance. All who dream frequently are
+occasionally aware on awaking of having greatly exercised their
+attention on the images presented to them during sleep. I myself am
+often able to recall an<span class='pagenum'><a name="Page_174" id="Page_174">[Pg 174]</a></span> effort to see beautiful objects, which
+threatened to disappear from my field of vision, or to catch faint
+receding tones of preternatural sweetness; and some dreamers allege that
+they are able to retain a recollection of the feeling of strain
+connected with such exercise of attention in sleep.</p>
+
+<p>The main function of this voluntary attention in dream-life is seen in
+the selection of those images which are to pass the threshold of clear
+consciousness. I have already spoken of a selective action brought about
+by the ruling emotion. In this case, the attention is held captive by
+the particular feeling of the moment. Also a selective process goes on
+in the case of the action of those associative dispositions just
+referred to. But in each of these cases the action of selective
+attention is comparatively involuntary, passive, and even unconscious,
+not having anything of the character of a conscious striving to compass
+some end. Besides this comparatively passive play of selective
+attention, there is an active play, in which there is a conscious wish
+to gain an end; in other words, the operation of a definite motive. This
+motive may be described as an intellectual impulse to connect and
+harmonize what is present to the mind. The voluntary kind of selection
+includes and transcends each of the involuntary kinds. It has as its
+result an imitation of that order which is brought about by what I have
+called the associative dispositions, only it consciously aims at this
+result. And it is a process controlled by a feeling, namely, the
+intellectual sentiment of consistency, which is not a mode of emotional
+excitement enthralling the will, but a calm motive, guiding the<span class='pagenum'><a name="Page_175" id="Page_175">[Pg 175]</a></span>
+activities of attention. It thus bears somewhat the same relation to the
+emotional selection already spoken of, as dramatic creation bears to
+lyrical composition.</p>
+
+<p>This process of striving to seize some connecting link, or thread of
+order, is illustrated whenever, in waking life, we are suddenly brought
+face to face with an unfamiliar scene. When taken into a factory, we
+strive to arrange the bewildering chaos of visual impressions under some
+scheme, by help of which we are said to understand the scene. So, if on
+entering a room we are plunged in <i>medias res</i> of a lively conversation,
+we strive to find a clue to the discussion. Whenever the meaning of a
+scene is not at once clear, and especially whenever there is an
+appearance of confusion in it, we are conscious of a painful feeling of
+perplexity, which acts as a strong motive to ever-renewed attention.<a name="FNanchor_97_97" id="FNanchor_97_97"></a><a href="#Footnote_97_97" class="fnanchor">[97]</a></p>
+
+<p>In touching on this intellectual impulse to connect the disconnected, we
+are, it is plain, approaching the question of the very foundations of
+our intellectual structure. That there is this impulse firmly rooted in
+the mature mind nobody can doubt; and that it manifests itself in early
+life in the child's recurring "Why?" is equally clear. But how we are to
+account for it, whether it is to be viewed as a mere result of the play
+of associated fragments of experience, or as something involved in the
+very process of the association of ideas itself, is a question into
+which I cannot here enter.<span class='pagenum'><a name="Page_176" id="Page_176">[Pg 176]</a></span></p>
+
+<p>What I am here concerned to show is that the search for consistency and
+connection in the manifold impressions of the moment is a deeply rooted
+habit of the mind, and one which is retained in a measure during sleep.
+When, in this state, our minds are invaded by a motley crowd of
+unrelated images, there results a disagreeable sense of confusion; and
+this feeling acts as a motive to the attention to sift out those
+products of the dream-fancy which may be made to cohere. When once the
+foundations of a dream-action are laid, new images must to some extent
+fit in with this; and here there is room for the exercise of a distinct
+impulse to order the chaotic elements of dream-fancy in certain forms.
+The perception of any possible relation between one of the crowd of new
+images ever surging above the level of obscure consciousness, and the
+old group at once serves to detain it. The concentration of attention on
+it, in obedience to this impulse to seek for an intelligible order, at
+once intensifies it and fixes it, incorporating it into the series of
+dream-pictures.</p>
+
+<p>Here is a dream which appears to illustrate this impulse to seek an
+intelligible order in the confused and disorderly. After being occupied
+with correcting the proofs of my volume on <i>Pessimism</i>, I dreamt that my
+book was handed to me by my publisher, fully illustrated with coloured
+pictures. The frontispiece represented the fantastic figure of a man
+gesticulating in front of a ship, from which he appeared to have just
+stepped. My publisher told me it was meant for Hamlet, and I immediately
+reflected that this character had been selected as a concrete example of
+the pessimistic tendency. I may add that, on awaking, I was distinctly<span class='pagenum'><a name="Page_177" id="Page_177">[Pg 177]</a></span>
+aware of having felt puzzled when dreaming, and of having striven to
+read a meaning into the dream.</p>
+
+<p>The <i>rationale</i> of this dream seems to me to be somewhat as follows. The
+image of the completed volume represented, of course, a recurring
+anticipatory image of waking life. The coloured plates were due probably
+to subjective optical sensations simultaneously excited, which were made
+to fit in (with or without an effort of voluntary attention) with the
+image of the book under the form of illustrations. But this stage of
+coherency did not satisfy the mind, which, still partly confused by the
+incongruity of coloured plates in a philosophic work, looked for a
+closer connection. The image of Hamlet was naturally suggested in
+connection with pessimism. The effort to discover a meaning in the
+pictures led to the fusion of this image with one of the subjective
+spectra, and in this way the idea of a Hamlet frontispiece probably
+arose.</p>
+
+<p>The whole process of dream-construction is clearly illustrated in a
+curious dream recorded by Professor Wundt.<a name="FNanchor_98_98" id="FNanchor_98_98"></a><a href="#Footnote_98_98" class="fnanchor">[98]</a> Before the house is a
+funeral procession: it is the burial of a friend, who has in reality
+been dead for some time past. The wife of the deceased bids him and an
+acquaintance who happens to be with him go to the other side of the
+street and join the procession. After she has gone away, his companion
+remarks to him, "She only said that because the cholera rages over
+yonder, and she wants to keep this side of the street to herself." Then
+comes an attempt to flee from the region of the cholera. Returning to
+his house, he finds the procession gone, but the street strewn with<span class='pagenum'><a name="Page_178" id="Page_178">[Pg 178]</a></span>
+rich nosegays; and he further observes crowds of men who seem to be
+funeral attendants, and who, like himself, are hastening to join the
+procession. These are, oddly enough, dressed in red. When hurrying on,
+it occurs to him that he has forgotten to take a wreath for the coffin.
+Then he wakes up with beating of the heart.</p>
+
+<p>The sources of this dream are, according to Wundt, as follows. First of
+all, he had, on the previous day, met the funeral procession of an
+acquaintance. Again, he had read of cholera breaking out in a certain
+town. Once more, he had talked about the particular lady with this
+friend, who had narrated facts which clearly proved her selfishness. The
+hastening to flee from the infected neighbourhood and to overtake the
+procession was prompted by the sensation of heart-beating. Finally, the
+crowd of red bier-followers, and the profusion of nosegays, owed their
+origin to subjective visual sensations, the "light-chaos" which often
+appears in the dark.</p>
+
+<p>Let us now see for a moment how these various elements may have become
+fused into a connected chain of events. First of all, it is clear that
+this dream is built up on a foundation of a gloomy tone of feeling,
+arising, as it would seem, from an irregularity of the heart's action.
+Secondly, it owes its special structure and its air of a connected
+sequence of events, to those tendencies, passive and active, to order
+the chaotic of which I have been speaking. Let us try to trace this out
+in detail.</p>
+
+<p>To begin with, we may suppose that the image of the procession occupies
+the dreamer's mind. From quite<span class='pagenum'><a name="Page_179" id="Page_179">[Pg 179]</a></span> another source the image of the lady
+enters consciousness, bringing with it that of her deceased husband and
+of the friend who has recently been talking about her. These new
+elements adapt themselves to the scene, partly by the passive mechanism
+of associative dispositions, and partly, perhaps, by the activity of
+voluntary selection. Thus, the idea of the lady's husband would
+naturally recall the fact of his death, and this would fall in with the
+pre-existing scene under the form of the idea that he is the person who
+is now being buried. The next step is very interesting. The image of the
+lady is associated with the idea of selfish motives. This would tend to
+suggest a variety of actions, but the one which becomes a factor of the
+dream is that which is specially adapted to the pre-existing
+representations, namely, of the procession on the further side of the
+street, and the cholera (which last, like the image of the funeral, is,
+we may suppose, due to an independent central excitation). That is to
+say, the request of the lady, and its interpretation, are a <i>resultant</i>
+of a number of adaptative or assimilative actions, under the sway of a
+strong desire to connect the disconnected, and a lively activity of
+attention. Once more, the feeling of oppression of the heart, and the
+subjective stimulation of the optic nerve, might suggest numberless
+images besides those of anxious flight and of red-clad men and nosegays;
+they suggest these, and not others, in this particular case, because of
+the co-operation of the impulse of consistency, which, setting out with
+the pre-existing mental images, selects from among many tendencies of
+reproduction those which happen to chime in with the scene.<span class='pagenum'><a name="Page_180" id="Page_180">[Pg 180]</a></span></p>
+
+
+<p class='center'><i>The Nature of Dream-Intelligence.</i></p>
+
+<p>It must not be supposed that this process of welding together the
+chaotic materials of our dreams is ever carried out with anything like
+the clear rational purpose of which we are conscious when seeking, in
+waking life, to comprehend some bewildering spectacle. At best it is a
+vague longing, and this longing, it may be added, is soon satisfied.
+There is, indeed, something, almost pathetic in the facility with which
+the dreamer's mind can be pacified with the least appearance of a
+connection. Just as a child's importunate "Why?" is often silenced by a
+ridiculous caricature of an explanation, so the dreamer's intelligence
+is freed from its distress by the least semblance of a uniting order.</p>
+
+<p>It thus remains true with respect even to our most coherent dreams, that
+there is a complete suspension, or at least a considerable retardation,
+of the highest operations of judgment and thought; also a great
+enfeeblement, to say the least of it, of those sentiments such as the
+feeling of consistency and the sense of the absurd which are so
+intimately connected with these higher intellectual operations.</p>
+
+<p>In order to illustrate how oddly our seemingly rational dreams
+caricature the operations of waking thought, I may, perhaps, be allowed
+to record two of my own dreams, of which I took careful note at the
+time.</p>
+
+<p>On the first occasion I went "in my dream" to the "Stores" in August,
+and found the place empty. A shopman brought me some large fowls. I
+asked their price, and he answered, "Tenpence a pound." I<span class='pagenum'><a name="Page_181" id="Page_181">[Pg 181]</a></span> then asked
+their weight, so as to get an idea of their total cost, and he replied,
+"Forty pounds." Not in the least surprised, I proceeded to calculate
+their cost: 40x10=400&divide;12=33&#8531;. But, oddly enough, I took this quotient
+as pence, just as though I had not already divided by 12, and so made
+the cost of a fowl to be 2<i>s.</i> 9<i>d.</i>, which seemed to me a fair enough
+price.</p>
+
+<p>In my second dream I was at Cambridge, among a lot of undergraduates. I
+saw a coach drive up with six horses. Three undergraduates got out of
+the coach. I asked them why they had so many horses, and they said,
+"Because of the luggage." I then said, "The luggage is much more than
+the undergraduates. Can you tell me how to express this in mathematical
+symbols? This is the way: if <i>x</i> is the weight of an undergraduate, then
+<i>x</i> + <i>x<sup>n</sup></i> represents the weight of an undergraduate and his luggage
+together." I noticed that this sally was received with evident
+enjoyment.<a name="FNanchor_99_99" id="FNanchor_99_99"></a><a href="#Footnote_99_99" class="fnanchor">[99]</a></p>
+
+<p>We may say, then, that the structure of our dreams, equally with the
+fact of their completely illusory character, points to the conclusion
+that during sleep, just as in the moments of illusion in waking life,
+there<span class='pagenum'><a name="Page_182" id="Page_182">[Pg 182]</a></span> is a deterioration of our intellectual life. The highest
+intellectual activities answering to the least stable nervous
+connections are impeded, and what of intellect remains corresponds to
+the most deeply organized connections.</p>
+
+<p>In this way, our dream-life touches that childish condition of the
+intelligence which marks the decadence of old age and the encroachments
+of mental disease. The parallelism between dreams and insanity has been
+pointed out by most writers on the subject. Kant observed that the
+madman is a dreamer awake, and more recently Wundt has remarked that,
+when asleep, we "can experience nearly all the phenomena which meet us
+in lunatic asylums." The grotesqueness of the combinations, the lack of
+all judgment as to consistency, fitness, and probability, are common
+characteristics of the short night-dream of the healthy and the long
+day-dream of the insane.<a name="FNanchor_100_100" id="FNanchor_100_100"></a><a href="#Footnote_100_100" class="fnanchor">[100]</a></p>
+
+<p>But one great difference marks off the two domains. When dreaming, we
+are still sane, and shall soon prove our sanity. After all, the dream of
+the sleeper is corrected, if not so rapidly as the illusion of the
+healthy waker. As soon as the familiar stimuli of light and sound set
+the peripheral sense-organs in activity, and call back the nervous
+system to its complete round of healthy action, the illusion disappears,
+and we smile at our alarms and agonies, saying, "Behold, it was a
+dream!"</p>
+
+<p>On the practical side, the illusions and hallucinations of sleep must be
+regarded as comparatively harm<span class='pagenum'><a name="Page_183" id="Page_183">[Pg 183]</a></span>less. The sleeper, in healthy conditions
+of sleep, ceases to be an agent, and the illusions which enthral his
+brain have no evil practical consequences. They may, no doubt, as we
+shall see in a future chapter, occasionally lead to a subsequent
+confusion of fiction and reality in waking recollection. But with the
+exception of this, their worst effect is probably the lingering sense of
+discomfort which a "nasty dream" sometimes leaves with us, though this
+may be balanced by the reverberations of happy dream-emotions which
+sometimes follow us through the day. And however this be, it is plain
+that any disadvantages thus arising are more than made good by the
+consideration that our liability to these nocturnal illusions is
+connected with the need of that periodic recuperation of the higher
+nervous structures which is a prime condition of a vigorous intellectual
+activity, and so of a triumph over illusion during waking life.</p>
+
+<p>For these reasons dreams may properly be classed with the illusions of
+normal or healthy life, rather than with those of disease. They
+certainly lie nearer this region than the very similar illusions of the
+somnambulist, which with respect to their origin appear to be more
+distinctly connected with a pathological condition of the nervous
+system, and which, with respect to their practical consequences may
+easily prove so disastrous.</p>
+
+
+<p class='center'><i>After-Dreams</i>.</p>
+
+<p>In concluding this account of dreams, I would call attention to the
+importance of the transition states between sleeping and waking, in
+relation to the pro<span class='pagenum'><a name="Page_184" id="Page_184">[Pg 184]</a></span>duction of sense-illusion. And this point may be
+touched on here all the more appropriately, since it helps to bring out
+the close relation between waking and sleeping illusion. The mind does
+not pass suddenly and at a bound from the condition of dream-fancy to
+that of waking perception. I have already had occasion to touch on the
+"hypnagogic state," that condition of somnolence or "sleepiness" in
+which external impressions cease to act, the internal attention is
+relaxed, and the weird imagery of sleep begins to unfold itself. And
+just as there is this anticipation of dream-hallucination in the
+presomnial condition, so there is the survival of it in the postsomnial
+condition. As I have observed, dreams sometimes leave behind them, for
+an appreciable interval after waking, a vivid after-impression, and in
+some cases even the semblance of a sense-perception.</p>
+
+<p>If one reflects how many ghosts and other miraculous apparitions are
+seen at night, and when the mind is in a more or less somnolent
+condition, the idea is forcibly suggested that a good proportion of
+these visions are the <i>d&eacute;bris</i> of dreams. In some cases, indeed, as that
+of Spinoza, already referred to, the hallucination (in Spinoza's case
+that of "a scurvy black Brazilian") is recognized by the subject himself
+as a dream-image.<a name="FNanchor_101_101" id="FNanchor_101_101"></a><a href="#Footnote_101_101" class="fnanchor">[101]</a> I am indebted to Mr. W.H. Pollock for a fact
+which curiously illustrates the position here adopted. A lady was
+staying at a country house. During the night and immediately on waking
+up she<span class='pagenum'><a name="Page_185" id="Page_185">[Pg 185]</a></span> had an apparition of a strange-looking man in medi&aelig;val costume,
+a figure by no means agreeable, and which seemed altogether unfamiliar
+to her. The next morning, on rising, she recognized the original of her
+hallucinatory image in a portrait hanging on the wall of her bedroom,
+which must have impressed itself on her brain before the occurrence of
+the apparition, though she had not attended to it. Oddly enough, she now
+learnt for the first time that the house at which she was staying had
+the reputation of being haunted, and by the very same somewhat
+repulsive-looking medi&aelig;val personage that had troubled her
+inter-somnolent moments. The case seems to me to be typical with respect
+to the genesis of ghosts, and of the reputation of haunted houses.</p>
+
+<hr style='width: 45%;' />
+
+<h3>NOTE.</h3>
+
+<h4>THE HYPNOTIC CONDITION.</h4>
+
+
+<p>I have not in this chapter discussed the relation of dreaming to
+hypnotism, or the state of artificially produced quasi-sleep, because
+the nature of this last is still but very imperfectly understood. In
+this condition, which is induced in a number of ways by keeping the
+attention fixed on some non-exciting object, and by weak continuous and
+monotonous stimulation, as stroking the skin, the patient can be made to
+act conformably to the verbal or other suggestion of the operator, or to
+the bodily position which he is made to assume. Thus, for example, if a
+glass containing<span class='pagenum'><a name="Page_186" id="Page_186">[Pg 186]</a></span> ink is given to him, with the command to drink, he
+proceeds to drink. If his hands are folded, he proceeds to act as if he
+were in church, and so on.</p>
+
+<p>Braid, the writer who did so much to get at the facts of hypnotism, and
+Dr. Carpenter who has helped to make known Braid's careful researches,
+regard the actions of the hypnotized subject as analogous to ideomotor
+movements; that is to say, the movements due to the tendency of an idea
+to act itself out apart from volition. On the other hand, one of the
+latest inquirers into the subject, Professor Heidenhain, of Breslau,
+appears to regard these actions as the outcome of "unconscious
+perceptions" (<i>Animal Magnetism</i>, English translation, p. 43, etc.).</p>
+
+<p>In the absence of certain knowledge, it seems allowable to argue from
+the analogy of natural sleep that the actions of the hypnotized patient
+are accompanied with the lower forms of consciousness, including
+sensation and perception, and that they involve dream-like
+hallucinations respecting the external circumstances of the moment.
+Regarding them in this light, the points of resemblance between
+hypnotism and dreaming are numerous and striking. Thus, Dr. Heidenhain
+tells us that the threshold or liminal value of stimulation is lowered
+just as in ordinary sleep sense-activity as a whole is lowered.
+According to Professor Weinhold, the hypnotic condition begins in a
+gradual loss of taste, touch, and the sense of temperature; then sight
+is gradually impaired, while hearing remains throughout the least
+interfered with.<a name="FNanchor_102_102" id="FNanchor_102_102"></a><a href="#Footnote_102_102" class="fnanchor">[102]</a> In<span class='pagenum'><a name="Page_187" id="Page_187">[Pg 187]</a></span> this way, the mind of the patient is largely
+cut off from the external world, as in sleep, and the power of
+orientation is lost. Moreover, there are all the conditions present,
+both positive and negative, for the hallucinatory transformation of
+mental images into percepts just as in natural sleep. Thus, the higher
+centres connected with the operations of reflection and reasoning are
+thrown <i>hors de combat</i> or, as Dr. Heidenhain has it, "inhibited."</p>
+
+<p>The condition of hypnotism is marked off from that of natural sleep,
+first of all, by the fact that the accompanying hallucinations are
+wholly due to external suggestion (including the effects of bodily
+posture). Dreams may, as we have seen, be very faintly modified by
+external influences, but during sleep there is nothing answering to the
+perfect control which the operator exercises over the hypnotized
+subject. The largest quantity of our "dream-stuff" comes, as we have
+seen, from within and not from without the organism. And this fact
+accounts for the chief characteristic difference between the natural and
+the hypnotic dream. The former is complex, consisting of crowds of
+images, and continually changing: the latter is simple, limited, and
+persistent. As Braid remarks, the peculiarity of hypnotism is that the
+attention is concentrated on a remarkably narrow field of mental images
+and ideas. So long as a particular bodily posture is assumed, so long
+does the corresponding illusion endure. One result of this, in
+connection with that impairing of sensibility already referred to, is
+the scope for a curious overriding of sense-impressions by the dominant
+illusory percept, a process that we have<span class='pagenum'><a name="Page_188" id="Page_188">[Pg 188]</a></span> seen illustrated in the active
+sense-illusions of waking life. Thus, if salt water is tasted and the
+patient is <i>told</i> that it is beer, he complains that it is sour.</p>
+
+<p>In being thus in a certain rapport, though so limited and unintelligent
+a rapport, with the external world, the mind of the hypnotized patient
+would appear to be nearer the condition of waking illusion than is the
+mind of the dreamer. It must be remembered, however, and this is the
+second point of difference between dreaming and hypnotism, that the
+hypnotized subject tends <i>to act out</i> his hallucinations. His
+quasi-percepts are wont to transform themselves into actions with a
+degree of force of which we see no traces in ordinary sleep. Why there
+should be this greater activity of the motor organs in the one condition
+than in the other, seems to be a point as yet unexplained. All
+sense-impressions and percepts are doubtless accompanied by some degree
+of impulse to movement, though, for some reason or another, in natural
+and healthy sleep these impulses are restricted to the stage of faint
+nascent stirrings of motor activity which hardly betray themselves
+externally. This difference, involving a great difference in the
+possible practical consequences of the two conditions of natural and
+hypnotic sleep, clearly serves to bring the latter condition nearer to
+that of insanity than the former condition is brought. A strong
+susceptibility to the hypnotic influence, such as Dr. Heidenhain
+describes, might, indeed, easily prove a very serious want of
+"adaptation of internal to external relations," whereas a tendency to
+dreaming would hardly prove a maladaptation at all.<span class='pagenum'><a name="Page_189" id="Page_189">[Pg 189]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER VIII.</h2>
+
+<h4>ILLUSIONS OF INTROSPECTION.</h4>
+
+
+<p>We have now, perhaps, sufficiently reviewed sense-illusions, both of
+waking life and of sleep. And having roughly classified them according
+to their structure and origin, we are ready to go forwards and inquire
+whether the theory thus reached can be applied to other forms of
+illusory error. And here we are compelled to inquire at the outset if
+anything analogous to sense-illusion is to be found in that other great
+region of presentative cognition usually marked off from external
+perception as internal perception, self-reflection, or introspection.</p>
+
+
+<p class='center'><i>Illusions of Introspection defined.</i></p>
+
+<p>This inquiry naturally sets out with the question: What is meant by
+introspection? This cannot be better defined, perhaps, than by saying
+that it is the mind's immediate reflective cognition of its own states
+as such.</p>
+
+<p>In one sense, of course, everything we know may be called a mental
+state, actual or imagined. Thus, a sense-impression is known, exactly
+like any other feeling of the mind, as a mental phenomenon or mental
+modifi<span class='pagenum'><a name="Page_190" id="Page_190">[Pg 190]</a></span>cation. Yet we do not usually speak of introspectively
+recognizing a sensation. Our sense-impressions are marked off from all
+other feelings by having an objective character, that is to say, an
+immediate relation to the external world, so that in attending to one of
+them our minds pass away from themselves in what Professor Bain calls
+the attitude of objective regard. Introspection is confined to feelings
+which want this intimate connection with the external region, and
+includes sensation only so far as it is viewed apart from external
+objects and on its mental side as a feeling, a process which is next to
+impossible where the sensation has little emotional colour, as in the
+case of an ordinary sensation of sight or of articulate sound.</p>
+
+<p>This being so, errors of introspection, supposing such to be found, will
+in the main be sufficiently distinguished from those of perception. Even
+an hallucination of sense, whether setting out from a subjective
+sensation or not, always contains the semblance of a sense-impression,
+and so would not be correctly classed with errors of introspection.</p>
+
+<p>Just as introspection must be marked off from perception, so must it be
+distinguished from memory. It may be contended that, strictly speaking,
+all introspection is retrospection, since even in attending to a present
+feeling the mind is reflectively representing to itself the immediately
+preceding momentary experience of that feeling. Yet the adoption of this
+view does not hinder us from drawing a broad distinction between acts of
+introspection and acts of memory. Introspection must be regarded as
+confined to the knowledge of immediately antecedent mental states<span class='pagenum'><a name="Page_191" id="Page_191">[Pg 191]</a></span> with
+reference to which, no error of memory can be supposed to arise.</p>
+
+<p>It follows from this that an illusion of introspection could only be
+found in connection with the apprehension of present or immediately
+antecedent mental states. On the other hand, any illusions connected
+with the consciousness of personal continuity and identity would fall
+rather under the class of mnemonic than that of introspective error.</p>
+
+<p>Once more, introspection must be carefully distinguished from what I
+have called belief. Some of our beliefs may be found to grow out of and
+be compounded of a number of introspections. Thus, my conception of my
+own character, or my psychological conception of mind as a whole, may be
+seen to arise by a combination of the results of a number of acts of
+introspection. Yet, supposing this to be so, we must still distinguish
+between the single presentative act of introspection and the
+representative belief growing out of it.</p>
+
+<p>It follows from this that, though an error of the latter sort might
+conceivably have its origin in one of the former; though, for example, a
+man's illusory opinion of himself might be found to involve errors of
+introspection, yet the two kinds of illusion would be sufficiently
+unlike. The latter would be a simple presentative error, the former a
+compound representative error.</p>
+
+<p>Finally, in order to complete this preliminary demarcation of our
+subject-matter, it is necessary to distinguish between an introspection
+(apparent or real) of a feeling or idea, and a process of inference
+based<span class='pagenum'><a name="Page_192" id="Page_192">[Pg 192]</a></span> on this feeling. The term introspective knowledge must, it is
+plain, be confined to what is or appears to be in the mind at the moment
+of inspection.</p>
+
+<p>By observing this distinction, we are in a position to mark off an
+<i>illusion</i> of introspection from a <i>fallacy</i> of introspection. The
+former differs from the latter in the absence of anything like a
+conscious process of inference. Thus, if we suppose that the derivation
+by Descartes of the fact of the existence of God from his possession of
+the idea to be erroneous, such a consciously performed act of reasoning
+would constitute a fallacy rather than an illusion of introspection.</p>
+
+<p>We may, then, roughly define an illusion of introspection as an error
+involved in the apprehension of the contents of the mind at any moment.
+If we mistake the quality or degree of a feeling or the structure of a
+complex mass of feeling, or if we confuse what is actually present to
+the mind with some inference based on this, we may be said to fall into
+an illusion of introspection.</p>
+
+<p>But here the question will certainly be raised: How can we conceive the
+mind erring as to the nature of its present contents; and what is to
+determine, if not my immediate act of introspection, what is present in
+my mind at any moment? Indeed, to raise the possibility of error in
+introspection seems to do away with the certainty of presentative
+knowledge.</p>
+
+<p>If, however, the reader will recall what was said in an earlier chapter
+about the possibility of error in recognizing the quality of a
+sense-impression, he will be prepared for a similar possibility here.
+What we are accustomed to call a purely presentative cognition<span class='pagenum'><a name="Page_193" id="Page_193">[Pg 193]</a></span> is, in
+truth, partly representative. A feeling as pure feeling is not known; it
+is only known when it is distinguished, as to quality or degree, and so
+classed or brought under some representation of a kind or description of
+feeling, as acute, painful, and so on. The accurate recognition of an
+impression of colour depends, as we have seen, on this process of
+classing being correctly performed. Similarly, the recognition of
+internal feelings implies the presence of the appropriate or
+corresponding class-representation. Accordingly, if it is possible for a
+wrong representation to get substituted for the right one, there seems
+to be an opening for error.</p>
+
+<p>Any error that would thus arise can, of course, only be determined as
+such in relation to some other act of introspection of the same mind. In
+matters of internal perception other minds cannot directly assist us in
+correcting error as they can in the case of external perception, though,
+as we shall see by-and-by, they may do so indirectly. The standard of
+reality directly applicable to introspective cognition is plainly what
+the individual mind recognizes at its best moments, when the processes
+of attention and classifying are accurately performed, and the
+representation may be regarded with certainty as answering to the
+feeling. In other words, in the sphere of internal, as in that of
+external experience, the criterion of reality is the average and
+perfect, as distinguished from the particular variable and imperfect act
+of cognition.</p>
+
+<p>We see, then, that error in the process of introspection is at least
+conceivable. And now let us<span class='pagenum'><a name="Page_194" id="Page_194">[Pg 194]</a></span> examine this process a little further, in
+order to find out what probabilities of error attach to it.</p>
+
+<p>To begin with, then, an act of introspection, to be complete, clearly
+involves the apprehension of an internal feeling or idea as something
+mental and marked off from the region of external experience. This
+distinct recognition of internal states of mind as such, in opposition
+to external impressions, is by no means easy, but presupposes a certain
+degree of intellectual culture, and a measure of the power of abstract
+attention.</p>
+
+
+<p class='center'><i>Confusion of Internal and External Experience.</i></p>
+
+<p>Accordingly, we find that where this is wanting there is a manifest
+disposition to translate internal feelings into terms of external
+impressions. In this way there may arise a slight amount of habitual and
+approximately constant error. Not that the process approaches to one of
+hallucination; but only that the internal feelings are intuited as
+having a cause or origin analogous to that of sense-impressions. Thus to
+the uncultivated mind a sudden thought seems like an audible
+announcement from without. The superstitious man talks of being led by
+some good or evil spirit when new ideas arise in his mind or new
+resolutions shape themselves. To the simple intelligence of the boor
+every thought presents itself as an analogue of an audible voice, and he
+commonly describes his rough musings as saying this and that to himself.
+And this, mode of viewing the matter is reflected even, in the language
+of cultivated persons. Thus we say, "The idea struck me," or "was borne
+in on me," "I<span class='pagenum'><a name="Page_195" id="Page_195">[Pg 195]</a></span> was forced to do so and so," and so on, and in this
+manner we tend to assimilate internal to external mental phenomena.</p>
+
+<p>Much the same thing shows itself in our customary modes of describing
+our internal feelings of pleasure and pain. When a man in a state of
+mental depression speaks of having "a load" on his mind it is evident
+that he is interpreting a mental by help of an analogy to a bodily
+feeling. Similarly, when we talk of the mind being torn by doubt or worn
+by anxiety. It would seem as though we tended mechanically to translate
+mental pleasures and pains into the language of bodily sensations.</p>
+
+<p>The explanation of this deeply rooted tendency to a slightly illusory
+view of our mental states is, I think, an easy one. For one thing, it
+follows from the relation of the mental image to the sense-impression
+that we should tend to assimilate the former to the latter as to its
+nature and origin. This would account for the common habit of regarding
+thoughts, which are of course accompanied by representatives of their
+verbal symbols, as internal voices, a habit which is probably especially
+characteristic of the child and the uncivilized man, as we have found it
+to be characteristic of the insane.</p>
+
+<p>Another reason, however, must be sought for the habit of assimilating
+internal feelings to external sensations. If language has been evolved
+as an incident of social life, at once one of its effects and its
+causes, it would seem to follow that it must have first shaped Itself to
+the needs of expressing these common objective experiences which we
+receive by way of our senses.<span class='pagenum'><a name="Page_196" id="Page_196">[Pg 196]</a></span> Our habitual modes of thought, limited as
+they are by language, retain traces of this origin. We cannot conceive
+any mental process except by some vague analogy to a physical process.
+In other words, we can even now only think with perfect clearness when
+we are concerned with some object of common cognition. Thus, the sphere
+of external sensation and of physical agencies furnishes us with the one
+type of thinkable thing or object of thought, and we habitually view
+subjective mental states as analogues of these.</p>
+
+<p>Still, it may be said that these slight nascent errors are hardly worth
+naming, and the question would still appear to recur whether there are
+other fully developed errors deserving to rank along with illusions of
+sense. Do we, it may be asked, ever actually mistake the quality,
+degree, or structure of our internal feelings in the manner hinted
+above, and if so, what is the range of such error? In order to
+appreciate the risks of such error, let us compare the process of
+self-observation with that of external perception with respect to the
+difficulties in the way of accurate presentative knowledge.</p>
+
+
+<p class='center'><i>Misreading of Internal Feelings.</i></p>
+
+<p>First of all, it is noteworthy that a state of consciousness at any one
+moment is an exceedingly complex thing. It is made up of a mass of
+feelings and active impulses which often combine and blend in a most
+inextricable way. External sensations come in groups, too, but as a rule
+they do not fuse in apparently simple wholes as our internal feelings
+often do. The very possibility of perception depends on a clear
+discrimination of sense-elements, for example, the several<span class='pagenum'><a name="Page_197" id="Page_197">[Pg 197]</a></span> sensations
+of colour obtained by the stimulation of different parts of the
+retina.<a name="FNanchor_103_103" id="FNanchor_103_103"></a><a href="#Footnote_103_103" class="fnanchor">[103]</a> But no such clearly defined mosaic of feelings presents
+itself in the internal region: one element overlaps and partly loses
+itself in another, and subjective analysis is often an exceedingly
+difficult matter. Our consciousness is thus a closely woven texture in
+which the mental eye often fails to trace the several threads or
+strands. Moreover, there is the fact that many of these ingredients are
+exceedingly shadowy, belonging to that obscure region of
+sub-consciousness which it is so hard to penetrate with the light of
+discriminative attention. This remark applies with particular force to
+that mass of organic feelings which constitutes what is known as
+c&oelig;n&aelig;sthesis; or vital sense.</p>
+
+<p>While, to speak figuratively, the minute anatomy of consciousness is
+thus difficult with respect to longitudinal sections of the mental
+column, it is no less difficult with respect to transverse sections.
+Under ordinary circumstances, external impressions persist so that they
+can be transfixed by a deliberate act of attention, and objects rarely
+flit over the external scene so rapidly as to allow us no time for a
+careful recognition of the impression. Not so in the case of the
+internal region of mind. The composite states of consciousness just
+described never remain perfectly uniform for the shortest conceivable
+duration. They change continually, just as the contents of the
+kaleidoscope vary with every shake of the instrument. Thus,<span class='pagenum'><a name="Page_198" id="Page_198">[Pg 198]</a></span> one shade
+of feeling runs into another in such a way that it is often impossible
+to detect its exact quality; and even when the character of the feeling
+does not change, its intensity is undergoing alterations so that an
+accurate observation of its quantity is impracticable. Also, in this
+unstable shifting internal scene features may appear for a duration too
+short to allow of close recognition. In this way it happens that we
+cannot sharply divide the feeling of the moment from its antecedents and
+its consequents.</p>
+
+<p>If, now, we take these facts in connection with what has been said above
+respecting the nature of the process of introspection, the probability
+of error will be made sufficiently clear. To transfix any particular
+feeling of the moment, to selectively attend to it, and to bring it
+under the proper representation, is an operation that requires time, a
+time which, though short, is longer than the fugitive character of so
+much of our internal mental life allows. From all of which it would
+appear to follow that it must be very easy to overlook, confuse, and
+transform, both as to quality and as to quantity, the actual ingredients
+of our internal consciousness.</p>
+
+<p>From these sources there spring a number of small errors of
+introspection which, to distinguish them from others to be spoken of
+presently, may be called passive. These would include all errors in
+detecting what is in consciousness due to the intricacies of the
+phenomena, and not aided by any strong basis. For example, a mental
+state may fail to disclose its component parts to introspective
+attention. Thus, a motive may enter into our action which is so
+entangled with other feelings as to<span class='pagenum'><a name="Page_199" id="Page_199">[Pg 199]</a></span> escape our notice. The fainter the
+feeling the greater the difficulty of detaching it and inspecting it in
+isolation. Again, an error of introspection may have its ground in the
+fugitive character of a feeling. If, for example, a man is asked whether
+a rapid action was a voluntary one, he may in retrospection easily
+imagine that it was not so, when as a matter of fact the action was
+preceded by a momentary volition. When a person exclaims, "I did a thing
+inadvertently or mechanically," it often means that he did not note the
+motive underlying the action. Such transitory feelings which cannot at
+the moment be seized by an act of attention are pretty certain to
+disappear at once, leaving not even a temporary trace in consciousness.</p>
+
+<p>We will now pass to the consideration of other illusions of
+introspection more analogous to what I have called the active illusions
+of perception. In our examination of these we found that a pure
+representation may under certain circumstances simulate the appearance
+of a presentation, that a mental image may approximate to a
+sense-impression. In the case of the internal feelings this liability
+shows itself in a still more striking form.</p>
+
+<p>The higher feelings or emotions are distinguished from the simple
+sense-feelings in being largely representative. Thus, a feeling of
+contentment at any moment, though no doubt conditioned by the bodily
+state and the character of the organic sensations or c&oelig;n&aelig;sthesis,
+commonly depends for the most part on intellectual representations of
+external circumstances or relations, and may be called an ideal
+foretaste of actual satisfactions, such as the pleasures of success,<span class='pagenum'><a name="Page_200" id="Page_200">[Pg 200]</a></span> of
+companionship, and so on. This being so, it is easy for imagination to
+call up a semblance of these higher feelings. Since they depend largely
+on representation, a mere act of representation may suffice to excite a
+degree of the feeling hardly distinguishable from the actual one. Thus,
+to imagine myself as contented is really to see myself at the moment as
+actually contented. Again, the actor, though, as we shall see by-and-by,
+he does not feel all that the spectator is apt to attribute to him,
+tends, when vividly representing to himself a particular shade of
+feeling, to regard himself as actually feeling in this way. Thus, it is
+said of Garrick, that when acting Richard III., he felt himself for the
+moment to be a villain.</p>
+
+<p>We should expect from all this that in the act of introspection the mind
+is apt, within certain limits, to find what it is prepared to find. And
+since there is in these acts often a distinct wish to detect some
+particular feeling, we can see how easy it must be for a man through
+bias and a wrong focussing of the attention to deceive himself up to a
+certain point with respect to the actual contents of his mind.</p>
+
+<p>Let us examine one of these active illusions a little more fully. It
+would at first sight seem to be a perfectly simple thing to determine at
+any given moment whether we are enjoying ourselves, whether our
+emotional condition rises above the pleasure-threshold or point of
+indifference and takes on a positive hue of the agreeable or
+pleasurable. Yet there is good reason for supposing that people not
+unfrequently deceive themselves on this matter. It is, perhaps, hardly
+an exaggeration to say that most<span class='pagenum'><a name="Page_201" id="Page_201">[Pg 201]</a></span> of us are capable of imagining that we
+are having enjoyment when we conform to the temporary fashion of social
+amusement. It has been cynically observed that people go into society
+less in order to be happy than to seem so, and one may add that in this
+semblance of enjoyment they may, provided they are not <i>blas&eacute;</i>, deceive
+themselves as well as others. The expectation of enjoyment, the
+knowledge that the occasion is intended to bring about this result, the
+recognition of the external signs of enjoyment in others&mdash;all this may
+serve to blind a man in the earlier stages of social amusement to his
+actual mental condition.</p>
+
+<p>If we look closely into this variety of illusion, we shall see that it
+is very similar in its structure and origin to that kind of erroneous
+perception which arises from inattention to the actual impression of the
+moment under the influence of a strong expectation of something
+different. The representation of ourselves as entertained dislodges from
+our internal field of vision our actual condition, relegating this to
+the region of obscure consciousness. Could we for a moment get rid of
+this representation and look at the real feelings of the time, we should
+become aware of our error; and it is possible that the process of
+becoming <i>blas&eacute;</i> involves a waking up to a good deal of illusion of the
+kind.</p>
+
+<p>Just as we can thus deceive ourselves within certain limits as to our
+emotional condition, so we can mistake the real nature of our
+intellectual condition. Thus, when an idea is particularly grateful to
+our minds, we may easily imagine that we believe it, when in point<span class='pagenum'><a name="Page_202" id="Page_202">[Pg 202]</a></span> of
+fact all the time there is a sub-conscious process of criticism going
+on, which if we attended to it for a moment would amount to a distinct
+act of disbelief. Some persons appear to be capable of going on
+habitually practising this petty deceit on themselves, that is to say,
+imagining they believe what in fact they are strongly inclined to doubt.
+Indeed, this remark applies to all the grateful illusions respecting
+ourselves and others, which will have to be discussed by-and-by. The
+impulse to hold to the illusion in spite of critical reflection,
+involves the further introspective illusion of taking a state of doubt
+for one of assurance. Thus, the weak, flattered man or woman manages to
+keep up a sort of fictitious belief in the truth of the words which are
+so pleasant to the ear.</p>
+
+<p>It is plain that the external conditions of life impose on the
+individual certain habits of feeling which often conflict with his
+personal propensities. As a member of society he has a powerful motive
+to attribute certain feelings to himself, and this motive acts as a bias
+in disturbing his vision of what is actually in his mind. While this
+holds good of lighter matters, as that of enjoyment just referred to, it
+applies still more to graver matters. Thus, for example, a man may
+easily persuade himself that he feels a proper sentiment of indignation
+against a perpetrator of some mean or cruel act, when as a matter of
+fact his feeling is much more one of compassion for the previously liked
+offender. In this way we impose on ourselves, disguising our real
+sentiments by a thin veil of make-believe.</p>
+
+<p>So far I have spoken of an illusion of introspection<span class='pagenum'><a name="Page_203" id="Page_203">[Pg 203]</a></span> as analogous to
+the slight misapprehensions of sense-impression which were touched on in
+connection with illusions of sense (Chapter III.). It is to be observed,
+however, that the confusing of elements of consciousness, which is so
+prominent a factor in introspective illusion, involves a species of
+error closely analogous to a complete illusion of perception, that is to
+say, one which involves a misinterpretation of a sense-impression.</p>
+
+<p>This variety of illusion is illustrated in the case in which a present
+feeling or thought is confounded with some inference based on it. For
+example, a present thought may, through forgetfulness, be regarded as a
+new discovery. Its originality appears to be immediately made known in
+the very freshness which characterizes it. Every author probably has
+undergone the experience of finding that ideas which started up to his
+mind as fresh creations, were unconscious reminiscences of his own or of
+somebody else's ideas.</p>
+
+<p>In the case of present emotional states this liability to confuse the
+present and the past is far greater. Here there is something hardly
+distinguishable from an active illusion of sense-perception. In this
+condition of mind a man often says that he has an "intuition" of
+something supposed to be immediately given in the feeling itself. For
+instance, one whose mind is thrilled by the pulsation of a new joy
+exclaims, "This is the happiest moment of my life," and the assurance
+seems to be contained in the very intensity of the feeling itself. Of
+course, cool reflection will tell him that what he affirms is merely a
+belief, the accuracy of which presupposes processes of recollection and
+judgment, but to the man's mind<span class='pagenum'><a name="Page_204" id="Page_204">[Pg 204]</a></span> at the moment the supremacy of this
+particular joy is immediately intuited. And so with the assurance that
+the present feeling, for example of love, is undying, that it is equal
+to the most severe trials, and so on. A man is said to <i>feel</i> at the
+moment that it is so, though as the facts believed have reference to
+absent circumstances and events, it is plain that the knowledge is by no
+means intuitive.</p>
+
+<p>At such times our minds are in a state of pure feeling: intellectual
+discrimination and comparison are no longer possible. In this way our
+emotions in the moments of their greatest intensity carry away our
+intellects with them, confusing the region of pure imagination with that
+of truth and certainty, and even the narrow domain of the present with
+the vast domain of the past and future. In this condition differences of
+present and future may be said to disappear and the energy of the
+emotion to constitute an immediate assurance of its existence
+absolutely.<a name="FNanchor_104_104" id="FNanchor_104_104"></a><a href="#Footnote_104_104" class="fnanchor">[104]</a></p>
+
+<p>The great region for the illustration of these active illusions is that
+of the moral and religious life. With respect to our real motives, our
+dominant aspirations, and our highest emotional experiences, we are
+greatly liable to deceive ourselves. The moralist and the theologian
+have clearly recognized the possibilities of self-deception in matters
+of feeling and impulse. To<span class='pagenum'><a name="Page_205" id="Page_205">[Pg 205]</a></span> them it is no mystery that the human heart
+should mistake the fictitious for the real, the momentary and evanescent
+for the abiding. And they have recognized, too, the double bias in these
+errors, namely, the powerful disposition to exaggerate the intensity and
+persistence of a present feeling on the one hand, and on the other hand
+to take a mere wish to feel in a particular way for the actual
+possession of the feeling.</p>
+
+
+<p class='center'><i>Philosophic Illusions.</i></p>
+
+<p>The opinion of theologians respecting the nature of moral introspection
+presents a singular contrast to that entertained by some philosophers as
+to the nature of self-consciousness. It is supposed by many of these
+that in interrogating their internal consciousness they are lifted above
+all risk of error. The "deliverance of consciousness" is to them
+something bearing the seal of a supreme authority, and must not be
+called in question. And so they make an appeal to individual
+consciousness a final resort in all matters of philosophical dispute.</p>
+
+<p>Now, on the face of it, it does not seem probable that this operation
+should have an immunity from all liability to error. For the matters
+respecting which we are directed to introspect ourselves, are the most
+subtle and complex things of our intellectual and emotional life. And
+some of these philosophers even go so far as to affirm that the plain
+man is quite equal to the niceties of this process.</p>
+
+<p>It has been brought as a charge against some of these same philosophers
+that they have based certain of their doctrines on errors of
+introspection. This<span class='pagenum'><a name="Page_206" id="Page_206">[Pg 206]</a></span> charge must, of course, be received with some sort
+of suspicion here, since it has been brought forward by avowed disciples
+of an opposite philosophic school. Nevertheless, as there is from our
+present disinterested and purely scientific point of view a presumption
+that philosophers like other men are fallible, and since it is certain
+that philosophical introspection does not materially differ from other
+kinds, it seems permissible just to glance at some of these alleged
+illusions in relation to other and more vulgar forms. Further reference
+to them will be made at the end of our study.</p>
+
+<p>These so-called philosophical illusions will be found, like the vulgar
+ones just spoken of, to illustrate the distinction drawn between passive
+and active illusions. That is to say, the alleged misreading of
+individual consciousness would result now from a confusion of distinct
+elements, including wrong suggestion, due to the intricacies of the
+phenomena, now from a powerful predisposition to read something into the
+phenomena.</p>
+
+<p>A kind of illusion in which the passive element seems most conspicuous
+would be the error into which the interrogator of the individual
+consciousness is said to fall respecting simple unanalyzable states of
+mind. On the face of it, it is not likely that a mere inward glance at
+the tangle of conscious states should suffice to determine what is such
+a perfectly simple mental phenomenon. Accordingly, when a writer
+declares that an act of introspection demonstrates the simple
+unanalyzable character of such a feeling as the sentiment of beauty or
+that of moral approval, the opponent of this view clearly has some show
+of argument for saying that this simplicity may be altogether illusory<span class='pagenum'><a name="Page_207" id="Page_207">[Pg 207]</a></span>
+and due to the absence of a perfect act of attention. Similarly, when it
+is said that the idea of space contains no representations of muscular
+sensation, the statement may clearly arise from the want of a
+sufficiently careful kind of introspective analysis.<a name="FNanchor_105_105" id="FNanchor_105_105"></a><a href="#Footnote_105_105" class="fnanchor">[105]</a></p>
+
+<p>In most cases of these alleged philosophical errors, however, the active
+and passive factors seem to combine. There are certain intricacies in
+the mental phenomenon itself favouring the chances of error, and there
+are independent predispositions leading the mind to look at the
+phenomenon in a wrong way. This seems to apply to the famous declaration
+of a certain school of thinkers that by an act of introspection we can
+intuit the fact of liberty, that is to say, a power of spontaneous
+determination of action superior to and regulative of the influence of
+motives. It may be plausibly contended that this idea arises partly
+from<span class='pagenum'><a name="Page_208" id="Page_208">[Pg 208]</a></span> a mixing up of facts of present consciousness with inferences from
+them, and partly from a natural predisposition of the mind to invest
+itself with this supreme power of absolute origination.<a name="FNanchor_106_106" id="FNanchor_106_106"></a><a href="#Footnote_106_106" class="fnanchor">[106]</a></p>
+
+<p>In a similar way, it might be contended that other famous philosophic
+dicta are founded on a process of erroneous introspection of subjective
+mental states. In some cases, indeed, it seems a plausible explanation
+to regard these illusions as mere survivals in attenuated shadowy form
+of grosser popular illusions. But this is not yet the time to enter on
+these, which, moreover, hardly fall perhaps under our definition of an
+illusion of introspection.</p>
+
+
+<p class='center'><i>Value of the Introspective Method.</i></p>
+
+<p>In drawing up this rough sketch of the illusions of introspection, I
+have had no practical object in view. I have tried to look at the facts
+as they are apart from any conclusions to be drawn from them. The
+question how far the liability to error in any region of inquiry
+vitiates the whole process is a difficult one; and the question whether
+the illusions to which we are subject in introspection materially affect
+the value of self-knowledge as a whole and consequently of the
+introspective method in psychology, as many affirm, is too subtle a one
+to be fully treated now. All that I shall attempt here is to show that
+it does not do this any more than the risk of sense-illusion can be said
+materially to affect the value of external observation.<span class='pagenum'><a name="Page_209" id="Page_209">[Pg 209]</a></span></p>
+
+<p>It is to be noted first of all that the errors of introspection are much
+more limited than those of sense-perception. They broadly answer to the
+slight errors connected with the discrimination and recognition of the
+sense-impression. There is nothing answering to a complete hallucination
+in the sphere of the inner mental life. It follows, too, from what has
+been said above, that the amount of active error in introspection is
+insignificant, since the representation of a feeling or belief is so
+very similar to the actual experience of it.</p>
+
+<p>In brief, the errors of introspection, though numerous, are all too
+slight to render the process of introspection as a whole unsound and
+untrustworthy. Though, as we have seen, it involves, strictly speaking,
+an ingredient of representation, this fact does not do away with the
+broad distinction between presentative and representative cognition.
+Introspection is presentative in the sense that the reality constituting
+the object of cognition, the mind's present feeling, is as directly
+present to the knowing mind as anything can be conceived to be. It may
+be added that the power of introspection is a comparatively new
+acquisition of the human race, and that, as it improves, the amount of
+error connected with its operation may reasonably be expected to become
+infinitesimal.</p>
+
+<p>It is often supposed by those who undervalue the introspective method in
+psychology that there is a special difficulty in the detection of error
+in introspection, owing to the fact that the object of inspection is
+something individual and private, and not open to common scrutiny as the
+object of external perception.<span class='pagenum'><a name="Page_210" id="Page_210">[Pg 210]</a></span> Yet, while allowing a certain force to
+this objection I would point out, first of all, that even in
+sense-perception, what the individual mind is immediately certain of is
+its own sensations. The relatively perfect certainty which finally
+attaches to the presentative side of sense-perception is precisely that
+which finally attaches to the results of introspection.</p>
+
+<p>In the second place, it may be said that the contrast between the inner
+and the outer experience is much less than it seems. In many cases our
+emotions are the direct result of a common external cause, and even when
+they are not thus attached to some present external circumstance, we are
+able, it is admitted, by the use of language, roughly to compare our
+individual feelings. And such comparison is continually bringing to
+light the fact that there is a continuity in our mental structure, that
+our highest thoughts and emotions lead us back to our common
+sense-impressions, and that consequently, in spite of all individual
+differences of temperament and mental organization, our inner experience
+is in all its larger features a common experience.</p>
+
+<p>I may add that this supposition of the common nature of our internal
+experience, as a whole, not only underlies the science of psychology,
+but is implied in the very process of detecting and correcting errors of
+introspection. I do not mean that in matters of feeling "authority" is
+to override "private judgment." Our last resort with respect to things
+of the mind is, as I have said, that of careful self-inspection. And the
+progress of psychology and the correction of illusion proceed by means
+of an ever-improving exercise<span class='pagenum'><a name="Page_211" id="Page_211">[Pg 211]</a></span> of the introspective faculty. Yet such
+individual inspection can at least be <i>guided</i> by the results of others'
+similar inspection, and should be so guided as soon as a general
+consensus in matters of internal experience is fairly made out. In point
+of fact, the preceding discussion of illusions of introspection has
+plainly rested on the sufficiently verified assumption that the calmest
+and most efficient kind of introspection, in bringing to light what is
+permanent as compared with what is variable in the individual cognition,
+points in the direction of a common body of introspected fact.<span class='pagenum'><a name="Page_212" id="Page_212">[Pg 212]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER IX.</h2>
+
+<h4>OTHER QUASI-PRESENTATIVE ILLUSIONS: ERRORS OF<br />INSIGHT.</h4>
+
+
+<p>Besides the perception of external objects, and the inspection of our
+internal mental states, there are other forms of quasi-presentative
+cognition which need to be touched on here, inasmuch as they are
+sometimes erroneous and illusory.</p>
+
+<p>In the last chapter I alluded to the fact that emotion may arise as the
+immediate accompaniment of a sense-impression. When this is the case
+there is a disposition to read into the external object a quality
+answering to the emotion, just as there is a disposition to ascribe to
+objects qualities of heat and cold answering to the sensations thus
+called. And such a reference of an emotional result to an external
+exciting cause approximates in character to an immediate intuition. The
+cognition of the quality is instantaneous, and quite free from any
+admixture of conscious inference. Accordingly, we have to inquire into
+the illusory forms of such intuition, if such there be.<span class='pagenum'><a name="Page_213" id="Page_213">[Pg 213]</a></span></p>
+
+
+<p class='center'><i>&AElig;sthetic Intuition.</i></p>
+
+<p>Conspicuous among these quasi-presentative emotional cognitions is
+&aelig;sthetic intuition, that is to say, the perception of an object as
+beautiful. It is not necessary here to raise the question whether there
+is, strictly speaking, any quality in things answering to the sentiment
+of beauty in our minds: this is a philosophical and not a psychological
+question, and turns on the further question, what we mean by object. All
+that we need to assume here is that there are certain aspects of
+external things, certain relations of form, together with a power of
+exciting certain pleasurable ideas in the spectator's mind, which are
+commonly recognized as the cause of the emotion of beauty, and indeed
+regarded as constituting the embodiments of the objective quality,
+beauty. &AElig;sthetic intuition thus clearly implies the immediate assurance
+of the existence of a common source of &aelig;sthetic delight, a source bound
+up with an object of common sense-perception. And so we may say that to
+call a thing beautiful is more or less distinctly to recognize it as a
+cause of a present emotion, and to attribute to it a power of raising a
+kindred emotion in other minds.</p>
+
+
+<p class='center'><i>&AElig;sthetic Illusion.</i></p>
+
+<p>According to this view of the matter, an illusion of &aelig;sthetic intuition
+would arise whenever this power of affecting a number of minds
+pleasurably is wrongly attributed, by an act of "intuition," to an
+object of sense-perception, on the ground of a present personal
+feeling.<span class='pagenum'><a name="Page_214" id="Page_214">[Pg 214]</a></span></p>
+
+<p>Now, this error is by no means unfrequent. Our delight in viewing
+external things, though agreeing up to a certain point, does not agree
+throughout. It is a trite remark that there is a large individual
+factor, a considerable "personal equation," in matters of taste, as in
+other matters. Permanent differences of natural sensibility, of
+experience, of intellectual habits, and so on, make an object
+&aelig;sthetically impressive and valuable to one man and not to another. Yet
+these differences tend to be overlooked. The individual mind, filled
+with delight at some spectacle, automatically projects its feeling
+outwards in the shape of a cause of a common sentiment. And the force of
+this impulse cannot be altogether explained as the effect of past
+experiences and of association. It seems to involve, in addition, the
+play of social instincts, the impulse of the individual mind to connect
+itself in sympathy with the collective mind.</p>
+
+<p>Here, as in the other varieties of illusion already treated of, we may
+distinguish between a passive and an active side; only in this case the
+passive side must not be taken as corresponding to any common
+suggestions of the object, as in the case of perception proper. So far
+as an illusion of &aelig;sthetic intuition may be considered as passive, it
+must be due to the effect of circumscribed individual associations with
+the object.</p>
+
+<p>All agree that what is called beauty consists, to a considerable extent,
+of a power of awaking pleasant suggestions, but in order that these
+should constitute a ground of &aelig;sthetic value, they must be common,
+participated in by all, or at least by an indefinite number. This will
+be the case when the association rests on our<span class='pagenum'><a name="Page_215" id="Page_215">[Pg 215]</a></span> common every-day
+experiences, and our common knowledge of things, as in the case of the
+peaceful beauty of an ascending curl of blue smoke in a woody landscape,
+or the awful beauty of a lofty precipice. On the other hand, when the
+experience and recollections, which are the source of the pleasure, are
+restricted and accidental, any attribution of objective worth is
+illusory. Thus, the ascription of beauty to one's native village, to
+one's beloved friends, and so on, in so far as it carries the conviction
+of objective worth, may imply a confusion of the individual with the
+common experience.</p>
+
+<p>The active side of this species of illusions would be illustrated in
+every instance of ascribing beauty to objects which is due, in a
+considerable measure at least, to some pre-existing disposition in the
+mind, whether permanent or temporary. A man brings his peculiar habits
+of thought and feeling to the contemplation of objects, and the &aelig;sthetic
+impression produced is coloured by these predispositions. Thus, a person
+of a sad and gloomy cast of mind will be disposed to see a sombre beauty
+where other eyes see nothing of the kind. And then there are all the
+effects of temporary conditions of the imagination and the feelings.
+Thus, the individual mind may be focussed in a certain way through the
+suggestion of another. People not seldom see a thing to be beautiful
+because they are told that it is so. It might not be well to inquire too
+curiously how many of the frequenters of the annual art exhibitions use
+their own eyes in framing their &aelig;sthetic judgments. Or the temporary
+predisposition may reside in a purely<span class='pagenum'><a name="Page_216" id="Page_216">[Pg 216]</a></span> personal feeling or desire
+uppermost at the time. Our enjoyment of nature or of art is coloured by
+our temporary mood. There are moments of exceptional mental
+exhilaration, when even a commonplace scene will excite an appreciable
+kind of admiration. Or there may be a strong wish to find a thing
+beautiful begotten of another feeling. Thus, a lover desires to find
+beauty in his mistress; or, having found it in her face and form,
+desires to find a harmonious beauty in her mind. In these different ways
+temporary accidents of personal feeling and imagination enter into and
+determine our &aelig;sthetic intuition, making it deviate from the common
+standard. This kind of error may even approximate in character to an
+hallucination of sense when there is nothing answering to a common
+source of &aelig;sthetic pleasure. Thus, the fond mother, through the very
+force of her affection, will construct a beauty in her child, which for
+others is altogether non-existent.</p>
+
+<p>What applies to the perception of beauty in the narrow sense will apply
+to all other modes of &aelig;sthetic intuition, as that of the sublime and the
+ludicrous, and the recognition of the opposite of beauty or the ugly. In
+like manner, it will apply to moral intuition in so far as it is an
+instantaneous recognition of a certain quality in a perceived action
+based on, or at least conjoined with, a particular emotional effect. In
+men's intuitive judgments respecting the right and the wrong, the noble
+and base, the admirable and contemptible, and so on, we may see the same
+kind of illusory universalizing of personal feeling as we have seen in
+their judgments respecting the beautiful. And the<span class='pagenum'><a name="Page_217" id="Page_217">[Pg 217]</a></span> sources of the error
+are the same in the two cases. Accidents of experience, giving special
+associations to the actions, will not unfrequently warp the individual
+intuition. Ethical culture, like &aelig;sthetic culture, means a continual
+casting aside of early illusory habits of intuition. And further, moral
+intuition illustrates all those effects of feeling which we have briefly
+traced in the case of &aelig;sthetic intuition. The perversions of the moral
+intuition under the sway of prejudice are too familiar to need more than
+a bare allusion.</p>
+
+
+<p class='center'><i>Nature of Insight.</i></p>
+
+<p>There remains one further mode of cognition which approximates in
+character to presentative knowledge, and is closely related to external
+perception. I refer to the commonly called "intuitive" process by which
+we apprehend the feelings and thoughts of other minds through the
+external signs of movement, vocal sound, etc., which make up expression
+and language. This kind of knowledge, which is not sufficiently marked
+off from external perception on the one side and introspection on the
+other, I venture to call Insight.</p>
+
+<p>I am well aware that this interpretation of the mental states of others
+is commonly described as a process of inference involving a conscious
+reference to our own similar experiences. I willingly grant that it is
+often so. At the same time, it must be perfectly plain that it is not
+always so. It is, indeed, doubtful whether in its first stages in early
+life it is invariably so, for there seem to be good reasons for
+attributing to the infant mind a certain degree of instinctive or
+inherited<span class='pagenum'><a name="Page_218" id="Page_218">[Pg 218]</a></span> capability in making out the looks and tones of others.<a name="FNanchor_107_107" id="FNanchor_107_107"></a><a href="#Footnote_107_107" class="fnanchor">[107]</a>
+And, however this may be, it is certain that with the progress of life a
+good part of this interpretation comes to be automatic or unconscious,
+approximating in character to a sense-perception. To recognize
+contentment in a placid smile is, one would say, hardly less immediate
+and intuitive than to recognize the coolness of a stream.</p>
+
+<p>We must, of course, all allow that the fusion of the presentative and
+the representative element is, speaking generally, more complete in the
+case of sense-perception than in that here considered. In spite of
+Berkeley's masterly account of the <i>rationale</i> of visual perception as
+an interpretation of "visual language" and all that has confirmed it,
+the plain man cannot, at the moment of looking at an object, easily
+bring himself to admit that distance is not directly present to his
+vision. On the other hand, on cool reflection, he will recognize that
+the complacent benevolent sentiment is distinct from the particular
+movements and changes in the eye and other features which express it.
+Yet, while admitting this, I must contend that there is no very hard and
+fast line dividing the two processes, but that the reading of others'
+feelings approximates in character to an act of perception.</p>
+
+<p>An intuitive insight may, then, be defined as that instantaneous,
+automatic, or "unconscious" mode of<span class='pagenum'><a name="Page_219" id="Page_219">[Pg 219]</a></span> interpreting another's feeling
+which occurs whenever the feeling is fully expressed, and when its signs
+are sufficiently familiar to us. This definition will include the
+interpretation of thoughts by means of language, though not, of course,
+the belief in an objective fact grounded on a recognition of another's
+belief. On the other hand, it will exclude all the more complex
+interpretations of looks and words which imply conscious comparison,
+reflection, and reasoning. Further, it will exclude a large part of the
+interpretation of actions as motived, since this, though sometimes
+approaching the intuitive form, is for the most part a process of
+conjectural or doubtful inference, and wanting in the immediate
+assurance which belongs to an intuitive reading of a present emotion or
+thought.</p>
+
+<p>From this short account of the process of insight, its relation to
+perception and introspection becomes pretty plain. On the one hand, it
+closely resembles sense-perception, since it proceeds by the
+interpretation of a sense-impression by means of a representative image.
+On the other hand, it differs from sense-perception, and is more closely
+allied to introspection in the fact that, while the process of
+interpretation in the former case is a reconstruction of <i>external</i>
+experiences, in the latter case it is a reconstruction of <i>internal</i>
+experiences. To intuit another's feeling is clearly to represent to
+ourselves a certain kind of internal experience previously known, in its
+elements at least, by introspection, while these represented experiences
+are distinctly referred to another personality.</p>
+
+<p>And now we see what constitutes the object of insight. This is, in part,
+a common experience, as in<span class='pagenum'><a name="Page_220" id="Page_220">[Pg 220]</a></span> the case of sense-perception and &aelig;sthetic
+intuition, since to perceive another's feeling is implicitly to cognize
+the external conditions of a common insight. But this is clearly not the
+whole, nor even the main part of objective reality in this act of
+cognition. An intuitive insight differs from a sense-perception in that
+it involves an immediate assurance of the existence of a feeling
+presentatively known, though not to our own minds. The object in insight
+is thus a presentative feeling as in introspection, though not our own,
+but another's. And so it differs from the object in sense-perception in
+so far as this last involves sense-experiences, as muscular and tactual
+feelings, which are not <i>at the moment</i> presentatively known to any
+mind.</p>
+
+
+<p class='center'><i>Illusions of Insight.</i></p>
+
+<p>And now we are in a position, perhaps, to define an illusion of insight,
+and to inquire whether there is anything answering to our definition. An
+illusory insight is a quasi-intuition of another's feelings which does
+not answer to the internal reality as presentatively known to the
+subject himself. In spite of the errors of introspection dealt with in
+the last chapter, nobody will doubt that, when it is a question between
+a man's knowing what is at the moment in his own mind and somebody
+else's knowing, logic, as well as politeness, requires us to give
+precedence to the former.</p>
+
+<p>An illusion of insight, like the other varieties of illusion already
+dealt with, may arise either by way of wrong suggestion or by way of a
+warping preconception. Let us look at each of these sources apart.</p>
+
+<p>Our insights, like our perceptions, though intuitive<span class='pagenum'><a name="Page_221" id="Page_221">[Pg 221]</a></span> in form, are
+obviously determined by previous experience, association, and habit.
+Hence, on its passive side, an illusion of insight may be described as a
+wrong interpretation of a new or exceptional case. For example, having
+associated the representation of a slight feeling of astonishment with
+uplifted eyebrows, we irresistibly tend to see a face in which this is a
+constant feature as expressing this particular shade of emotion. In this
+way we sometimes fall into grotesque errors as to mental traits. And the
+most practised physiognomist may not unfrequently err by importing the
+results of his special circle of experiences into new and unlike cases.</p>
+
+<p>Much the same thing occurs in language. Our timbre of voice, our
+articulation, and our vocabulary, like our physiognomy, have about them
+something individual, and error often arises from overlooking this, and
+hastily reading common interpretations into exceptional cases. The
+misunderstandings that arise even among the most open and confiding
+friends sufficiently illustrate this liability to error.</p>
+
+<p>Sometimes the error becomes more palpable, as, for example, when we
+visit another country. A foreign language, when heard, provokingly
+suggests all kinds of absurd meanings through analogies to our familiar
+tongue. Thus, the Englishman who visits Germany cannot, for a time, hear
+a lady use the expression, "Mein Mann," without having the amusing
+suggestion that the speaker is wishing to call special attention to the
+fact of her husband's masculinity. And doubtless the German who visits
+us derives a similar kind of amusement from such involuntary
+comparisons.<span class='pagenum'><a name="Page_222" id="Page_222">[Pg 222]</a></span></p>
+
+<p>A fertile source of illusory insight is, of course, conscious deception
+on the part of others. The rules of polite society require us to be
+hypocrites in a small way, and we have occasionally to affect the signs
+of amiability, interest, and amusement, when our actual sentiment is one
+of indifference, weariness, or even positive antipathy. And in this way
+a good deal of petty illusion arises. Although we may be well aware of
+the general untrustworthiness of this society behaviour, such is the
+force of association and habit, that the bland tone and flattering word
+irresistibly excite a momentary feeling of gratification, an effect
+which is made all the more easy by the co-operation of the recipient's
+own wishes, touched on in the last chapter.</p>
+
+<p>Among all varieties of this deception, that of the stage is the most
+complete. The actor is a man who has elaborately trained himself in the
+simulation of certain feelings. And when his acting is of the best
+quality, and the proper bodily attitude, gesture, tone of voice, and so
+on, are hit off, the force of the illusion completely masters us. For
+the moment we lose sight of the theatrical surroundings, and see the
+actor as really carried away by the passion which he so closely
+imitates. Histrionic illusion is as complete as any artistic variety can
+venture to be.<a name="FNanchor_108_108" id="FNanchor_108_108"></a><a href="#Footnote_108_108" class="fnanchor">[108]</a></p>
+
+<p>I have said that our insights are limited by our own mental experience,
+and so by introspection. In truth, every interpretation of another's
+look and word<span class='pagenum'><a name="Page_223" id="Page_223">[Pg 223]</a></span> is determined ultimately, not by what we have previously
+observed in others, but by what we have personally felt, or at least
+have in a sense made our own by intense sympathy. Hence we may, in
+general, regard an illusion of insight on the active side as a hasty
+projection of our own feelings, thoughts, etc., into other minds.</p>
+
+<p>We habitually approach others with a predisposition to attribute to them
+our own modes of thinking and feeling. And this predisposition will be
+the more powerful, the more desirous we are for sympathy, and for that
+confirmation of our own views which the reflection of another mind
+affords. Thus, when making a new acquaintance, people are in general
+disposed to project too much of themselves into the person who is the
+object of inspection. They intuitively endow him with their own ideas,
+ways of looking at things, prejudices of sentiment, and so on, and
+receive something like a shock when later on they find out how different
+he is from this first hastily formed and largely performed image.</p>
+
+<p>The same thing occurs in the reading of literature, and the appreciation
+of the arts of expression generally. We usually approach an author with
+a predisposition to read our own habits of thought and sentiment into
+his words. It is probably a characteristic defect of a good deal of
+current criticism of remote writers to attribute to them too much of our
+modern conceptions and aims. Similarly, we often import our own special
+feelings into the utterances of the poet and of the musical composer.
+That much of this intuition is illusory, may be seen by a little
+attention to the "in<span class='pagenum'><a name="Page_224" id="Page_224">[Pg 224]</a></span>tuitions" of different critics. Two readers of
+unlike emotional organization will find incompatible modes of feeling in
+the same poet. And everybody knows how common it is for musical critics
+and amateurs to discover quite dissimilar feelings in the same
+composition.<a name="FNanchor_109_109" id="FNanchor_109_109"></a><a href="#Footnote_109_109" class="fnanchor">[109]</a></p>
+
+<p>The effect of this active projection of personal feeling will, of
+course, be seen most strikingly when there is a certain variety of
+feeling actually excited at the time in the observer's mind. A man who
+is in a particularly happy mood tends to reflect his exuberant gladness
+on others. The lover, in the moment of exalted emotion, reads a response
+to all his aspirations in his mistress's eyes. Again, a man will tend to
+project his own present ideas into the minds of others, and so imagine
+that they know what he knows; and this sometimes leads to a comical kind
+of embarrassment, and even to a betrayal of something which it was the
+interest of the person to keep to himself. Once more, in interpreting
+language, we may sometimes catch ourselves mistaking the meaning, owing
+to the presence of a certain idea in the mind at the time. Thus, if I
+have just been thinking of Comte, and overhear a person exclaim, "I'm
+positive," I irresistibly tend, for the moment, to ascribe to him an
+avowal of discipleship to the great positivist.</p>
+
+
+<p class='center'><i>Poetic Illusion.</i></p>
+
+<p>The most remarkable example of this projection of<span class='pagenum'><a name="Page_225" id="Page_225">[Pg 225]</a></span> feeling is
+undoubtedly illustrated in the poetic interpretation of inanimate
+nature. The personification of tree, mountain, ocean, and so on,
+illustrates, no doubt, the effect of association and external
+suggestion; for there are limits to such personification. But
+resemblance and suggestion commonly bear, in this case, but a small
+proportion to active constructive imagination. One might, perhaps, call
+this kind of projection the hallucination of insight, since there is
+nothing objective corresponding to the interpretative image.</p>
+
+<p>The imaginative and poetic mind is continually on the look out for hints
+of life, consciousness, and emotion in nature. It finds a certain kind
+of satisfaction in this half-illusory, dream-like transformation of
+nature. The deepest ground of this tendency must probably be looked for
+in the primitive ideas of the race, and the transmission by inheritance
+of the effect of its firmly fixed habits of mind. The undisciplined mind
+of early man, incapable of distinguishing the object of perception from
+the product of spontaneous imagination, and taking his own double
+existence as the type of all existence, actually saw the stream, the
+ocean, and the mountain as living beings; and so firmly rooted is this
+way of regarding objects, that even our scientifically trained minds
+find it a relief to relapse occasionally into it.<a name="FNanchor_110_110" id="FNanchor_110_110"></a><a href="#Footnote_110_110" class="fnanchor">[110]</a></p>
+
+<p>While there is this general imaginative disposition in the poetic mind
+to endow nature with life and con<span class='pagenum'><a name="Page_226" id="Page_226">[Pg 226]</a></span>sciousness, there are special
+tendencies to project the individual feelings into objects. Every
+imaginative mind looks for reflections of its own deepest feelings in
+the world about it. The lonely embittered heart, craving for sympathy,
+which he cannot meet with in his fellow-man, finds traces of it in the
+sighing of the trees or the moaning of the sad sea-wave. Our Poet
+Laureate, in his great elegy, has abundantly illustrated this impulse of
+the imagination to reflect its own emotional colouring on to inanimate
+things: for example in the lines&mdash;</p>
+
+<p>
+<span style="margin-left: 2em;">"The wild unrest that lives in woe</span><br />
+<span style="margin-left: 1em;">Would dote and pore on yonder cloud</span><br />
+<span style="margin-left: 1em;">That rises upward always higher,</span><br />
+<span style="margin-left: 2.3em;">And onward drags a labouring breast,</span><br />
+<span style="margin-left: 2.3em;">And topples round the dreary west,</span><br />
+<span style="margin-left: 1em;">A looming bastion fringed with fire."</span><br />
+</p>
+
+<p>So far I have been considering active illusions of insight as arising
+through the play of the impulse of the individual mind to project its
+feelings outwards, or to see their reflections in external things. I
+must now add that active illusion may be due to causes similar to those
+which we have seen to operate in the sphere of illusory perception and
+introspection. That is to say, there may be a disposition, permanent or
+temporary, to ascribe a certain kind of feeling to others in accordance
+with our wishes, fears, and so on.</p>
+
+<p>To give an illustration of the permanent causes, it is well known that a
+conceited man will be disposed to attribute admiration of himself to
+others. On the other hand, a shy, timid person will be prone to read
+into other minds the opposite kind of feeling.<span class='pagenum'><a name="Page_227" id="Page_227">[Pg 227]</a></span></p>
+
+<p>Coming to temporary forces, we find that any expectation to meet with a
+particular kind of mental trait in a new acquaintance will dispose the
+observer hastily and erroneously to attribute corresponding feelings to
+the person. And if this expectation springs out of a present feeling,
+the bias to illusory insight is still more powerful. For example, a
+child that fears its parent's displeasure will be prone to misinterpret
+the parent's words and actions, colouring them according to its fears.
+So an angry man, strongly desirous of making out that a person has
+injured him, will be disposed to see signs of conscious guilt in this
+person's looks or words. Similarly, a lover will read fine thoughts or
+sentiments into the mind of his mistress under the influence of a strong
+wish to admire.</p>
+
+<p>And what applies to the illusory interpretation of others' feelings
+applies to the ascription of feelings to inanimate objects. This is due
+not simply to the impulse to expand one's conscious existence through
+far-reaching resonances of sympathy, but also to a permanent or
+temporary disposition to attribute a certain kind of feeling to an
+object. Thus, the poet personifies nature in part because his emotional
+cravings prompt him to construct the idea of something that can be
+admired or worshipped. Once more, the action of a momentary feeling when
+actually excited is seen in the "mechanical" impulse of a man to
+retaliate when he strikes his foot against an object, as a chair, which
+clearly involves a tendency to attribute an intention to hurt to the
+unoffending body, and the <i>rationale</i> of which odd procedure is pretty
+correctly expressed in the popular phrase: "It relieves the feelings."<span class='pagenum'><a name="Page_228" id="Page_228">[Pg 228]</a></span></p>
+
+<p>It is worth noting, perhaps, that these illusions of insight, like those
+of perception, may involve an inattention to the actual impression of
+the moment. To erroneously attribute a feeling to another through an
+excess of sympathetic eagerness is often to overlook what a perfectly
+dispassionate observer would see, as, for example, the immobility of the
+features or the signs of a deliberate effort to simulate. This
+inattention will, it is obvious, be greatest in the poetic attribution
+of life and personality to natural objects, in so far as this
+approximates to a complete momentary illusion. To see a dark overhanging
+rock as a grim sombre human presence, is for the moment to view it under
+this aspect only, abstracting from its many obvious unlikenesses.</p>
+
+<p>In the same manner, a tendency to read a particular meaning into a word
+may lead to the misapprehension of the word. To give an illustration: I
+was lately reading the fifth volume of G. H. Lewes's <i>Problems of Life
+and Mind</i>. In reading the first sentence of one of the sections, I again
+and again fell into the error of taking "The great Lagrange," for "The
+great Language." On glancing back I saw that the section was headed "On
+Language," and I at once recognized the cause of my error in the
+pre-existence in my mind of the representative image of the word
+"language."</p>
+
+<p>In concluding this short account of the errors of insight, I may observe
+that their range is obviously much greater than that of the previously
+considered classes of presentative illusion. This is, indeed, involved
+in what has been said about the nature of the process. Insight, as we
+have seen, though here classed<span class='pagenum'><a name="Page_229" id="Page_229">[Pg 229]</a></span> with preservative cognition, occupies a
+kind of border-land between immediate knowledge or intuition and
+inference, shading off from the one to the other. And in the very nature
+of the case the scope for error must be great. Even overlooking human
+reticence, and, what is worse, human hypocrisy, the conditions of an
+accurate reading of others' minds are rarely realized. If, as has been
+remarked by a good authority, one rarely meets, even among intelligent
+people, with a fairly accurate observer of external things, what shall
+be said as to the commonly claimed power of "intuitive insight" into
+other people's thoughts and feelings, as though it were a process above
+suspicion? It is plain, indeed, on a little reflection, that, taking
+into account what is required in the way of large and varied experience
+(personal and social), a habit of careful introspection, as well as a
+habit of subtle discriminative attention to the external signs of mental
+life, and lastly, a freedom from prepossession and bias, only a very few
+can ever hope even to approximate to good readers of character.</p>
+
+<p>And then we have to bear in mind that this large amount of error is apt
+to remain uncorrected. There is not, as in the case of external
+perception, an easy way of verification, by calling in another sense; a
+misapprehension, once formed, is apt to remain, and I need hardly say
+that errors in these matters of mutual comprehension have their palpable
+practical consequences. All social cohesion and co-operation rest on
+this comprehension, and are limited by its degree of perfection. Nay,
+more, all common knowledge itself, in so far as it depends on a mutual
+communication of impressions,<span class='pagenum'><a name="Page_230" id="Page_230">[Pg 230]</a></span> ideas, and beliefs, is limited by the
+fact of this great liability to error in what at first seems to be one
+of the most certain kinds of knowledge.</p>
+
+<p>In view of this depressing amount of error, our solace must be found in
+the reflection that this seemingly perfect instrument of intuitive
+insight is, in reality, like that of introspection, in process of being
+fashioned. Mutual comprehension has only become necessary since man
+entered the social state, and this, to judge by the evolutionist's
+measure of time, is not so long ago. A mental structure so complex and
+delicate requires for its development a proportionate degree of
+exercise, and it is not reasonable to look yet for perfect precision of
+action. Nevertheless, we may hope that, with the advance of social
+development, the faculty is continually gaining in precision and
+certainty. And, indeed, this hope is already assured to us in the fact
+that the faculty has begun to criticise itself, to distinguish between
+an erroneous and a true form of its-operation. In fact, all that has
+been here said about illusions of insight has involved the assumption
+that intellectual culture sharpens the power and makes it less liable to
+err.<span class='pagenum'><a name="Page_231" id="Page_231">[Pg 231]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER X.</h2>
+
+<h4>ILLUSIONS OF MEMORY.</h4>
+
+
+<p>Thus far we have been dealing with Presentative Illusions, that is to
+say, with the errors incident to the process of what may roughly be
+called presentative cognition. We have now to pass to the consideration
+of Representative Illusion, or that kind of error which attends
+representative cognition in so far as it is immediate or
+self-sufficient, and not consciously based on other cognition. Of such
+immediate representative cognition, memory forms the most conspicuous
+and most easily recognized variety. Accordingly, I proceed to take up
+the subject of the Illusions of Memory.<a name="FNanchor_111_111" id="FNanchor_111_111"></a><a href="#Footnote_111_111" class="fnanchor">[111]</a></p>
+
+<p>The mystery of memory lies in the apparent immediateness of the mind's
+contact with the vanished past. In "looking back" on our life, we seem
+to ourselves for the moment to rise above the limitations of<span class='pagenum'><a name="Page_232" id="Page_232">[Pg 232]</a></span> time, to
+undo its work of extinction, seizing again the realities which its
+on-rushing stream had borne far from us. Memory is a kind of
+resurrection of the buried past: as we fix our retrospective glance on
+it, it appears to start anew into life; forms arise within our minds
+which, we feel sure, must faithfully represent the things that were. We
+do not ask for any proof of the fidelity of this dramatic representation
+of our past history by memory. It is seen to be a faithful imitation,
+just because it is felt to be a revival of the past. To seek to make the
+immediate testimony of memory more sure seems absurd, since all our ways
+of describing and illustrating this mental operation assume that in the
+very act of performing it we do recover a part of our seemingly "dead
+selves."</p>
+
+<p>To challenge the veracity of a person's memory is one of the boldest
+things one can do in the way of attacking deep-seated conviction. Memory
+is the peculiar domain of the individual. In going back in recollection
+to the scenes of other years he is drawing on the secret store-house of
+his own consciousness, with which a stranger must not intermeddle. To
+cast doubt on a person's memory is commonly resented as an impertinence,
+hardly less rude than to question his reading of his own present mental
+state. Even if the challenger professedly bases his challenge on the
+testimony of his own memory, the challenged party is hardly likely to
+allow the right of comparing testimonies. He can in most cases boldly
+assert that those who differ from him are lacking in <i>his</i> power of
+recollection. The past, in becoming the past, has, for most people,
+ceased to be a common object of reference; it<span class='pagenum'><a name="Page_233" id="Page_233">[Pg 233]</a></span> has become a part of the
+individual's own inner self, and cannot be easily dislodged or shaken.</p>
+
+<p>Yet, although people in general are naturally disposed to be very
+confident about matters of recollection, reflective persons are pretty
+sure to find out, sooner or later, that they occasionally fall into
+errors of memory. It is not the philosopher who first hints at the
+mendacity of memory, but the "plain man" who takes careful note of what
+really happens in the world of his personal experience. Thus, we hear
+persons, quite innocent of speculative doubt, qualifying an assertion
+made on personal recollection by the proviso, "unless my memory has
+played me false." And even less reflective persons, including many who
+pride themselves on their excellent memory, will, when sorely pressed,
+make a grudging admission that they may, after all, be in error. Perhaps
+the weakest degree of such an admission, and one which allows to the
+conceding party a semblance of victory, is illustrated in the "last
+word" of one who has boldly maintained a proposition on the strength of
+individual recollection, but begins to recognize the instability of his
+position: "I either witnessed the occurrence or dreamt it." This is
+sufficient to prove that, with all people's boasting about the
+infallibility of memory, there are many who have a shrewd suspicion that
+some of its asseverations will not bear a very close scrutiny.</p>
+
+
+<p class='center'><i>Psychology of Memory.</i></p>
+
+<p>In order to understand the errors of memory, we must proceed, as in the
+case of illusions of perception,<span class='pagenum'><a name="Page_234" id="Page_234">[Pg 234]</a></span> by examining a little into the nature
+of the normal or correct process.</p>
+
+<p>An act of recollection is said by the psychologist to be purely
+representative in character, whereas perception is partly
+representative, partly preservative. To recall an object to the mind is
+to reconstruct the percept in the absence of a sense-impression.<a name="FNanchor_112_112" id="FNanchor_112_112"></a><a href="#Footnote_112_112" class="fnanchor">[112]</a></p>
+
+<p>An act of memory is obviously distinguished from one of simple
+imagination by the presence of a conscious reference to the past. Every
+recollection is an immediate reapprehension of some past object or
+event. However vague this reference may be, it must be there to
+constitute the process one of recollection.</p>
+
+<p>The every-day usages of language do not at first sight seem to
+consistently observe this distinction. When a boy says, "I remember my
+lesson," he appears to be thinking of the present only, and not
+referring to the past. In truth, however, there is a vague reference to
+the fact of retaining a piece of knowledge through a given interval of
+time.</p>
+
+<p>Again, when a man says, "I recollect your face," this means, "Your face
+seems familiar to me." Here again, though there is no definite reference
+to the past, there is a vague and indefinite one.</p>
+
+<p>It is plain from this definition that recollection is involved in all
+recognition or identification. Merely to be aware that I have seen a
+person before implies a minimum exercise of memory. Yet we may roughly
+distinguish the two actions of perception and recollection in the
+process of recognition. The mere<span class='pagenum'><a name="Page_235" id="Page_235">[Pg 235]</a></span> recognition of an object does not
+imply the presence of a distinct representative or mnemonic image. In
+point of fact, in so far as recognition is assimilation, it cannot be
+said to imply a <i>distinct</i> act of memory at all. It is only when
+similarity is perceived amid difference, only when the accompaniments or
+surroundings of the object as previously seen, differencing it from the
+object as now seen, are brought up to the mind that we may be said
+distinctly to recall the past. And our state of mind in recognizing an
+object or person is commonly an alternation between these two acts of
+separating the mnemonic image from the percept and so recalling or
+recollecting the past, and fusing the image and the percept in what is
+specifically marked off as recognition.<a name="FNanchor_113_113" id="FNanchor_113_113"></a><a href="#Footnote_113_113" class="fnanchor">[113]</a></p>
+
+<p>Although I have spoken of memory as a reinstatement in representative
+form of external experience, the term must be understood to include
+every revival of a past experience, whether external or internal, which
+is recognized as a revival. In a general way, the recallings of our
+internal feelings take place in close connection with the recollection
+of external circumstances or events, and so they may be regarded as
+largely conditioned by the laws of this second kind of reproduction.</p>
+
+<p>The old conceptions of mind, which regarded every mental phenomenon as a
+manifestation of an occult spiritual substance, naturally led to the
+supposition that an act of recollection involves the continued,
+un<span class='pagenum'><a name="Page_236" id="Page_236">[Pg 236]</a></span>broken existence of the reproductive or mnemonic image in the hidden
+regions of the mind. To recollect is, according to this view, to draw
+the image out of the dark vaults of unconscious mind into the upper
+chamber of illumined consciousness.</p>
+
+<p>Modern psychology recognizes no such pigeonhole apparatus in unconscious
+mind. On the purely psychical side, memory is nothing but an occasional
+reappearance of a past mental experience. And the sole mental conditions
+of this reappearance are to be found in the circumstances of the moment
+of the original experience and in those of the moment of the
+reappearance.</p>
+
+<p>Among these are to be specially noted, first of all, the degree of
+impressiveness of the original experience, that is to say, the amount of
+interest it awakened and of attention it excited. The more impressive
+any experience, the greater the chances of its subsequent revival.
+Moreover, the absence of impressiveness in the original experience may
+be made good either by a repetition of the actual experience or, in the
+case of non-recurring experiences, by the fact of previous mnemonic
+revivals.</p>
+
+<p>In the second place, the pre-existing mental states at the time of
+revival are essential conditions. It is now known that every
+recollection is determined by some link of association, that every
+mnemonic image presents itself in consciousness only when it has been
+preceded by some other mental state, presentative or representative,
+which is related to the image. This relation may be one of contiguity,
+that is to say, the original experiences may have occurred at the same<span class='pagenum'><a name="Page_237" id="Page_237">[Pg 237]</a></span>
+time or in close succession; or one of similarity (partial and not
+amounting to identity), as where the sight of one place or person
+recalls that of another place or person. Finally, it is to be observed
+that recollection is often an act, in the full sense of that term,
+involving an effort of voluntary attention at the moment of revival.</p>
+
+<p>Modern physiology has done much towards helping us to understand the
+nervous conditions of memory. The biologist regards memory as a special
+phase of a universal property of organic structure, namely,
+modifiability by the exercise of function, or the survival after any
+particular kind of activity of a disposition to act again in that
+particular way. The revival of a mental impression in the weaker form of
+an image is thus, on its physical side, due in part to this remaining
+functional disposition in the central nervous tracts concerned. And so,
+while on the psychical or subjective side we are unable to find anything
+permanent in memory, on the physical or objective side we do find such a
+permanent substratum.</p>
+
+<p>With respect to the special conditions of mnemonic revival at any time,
+physiology is less explicit. In a general way, it informs us that such a
+reinstatement of the past is determined by the existence of certain
+connections between the nervous structures concerned in the reviving and
+revived mental elements. Thus, it is said that when the sound of a name
+calls up in the mind a visual image of a person seen some time since, it
+is because connections have been formed between particular regions and
+modes of activity of the auditory and the visual centres.<span class='pagenum'><a name="Page_238" id="Page_238">[Pg 238]</a></span> And it is
+supposed that the existence of such connections is somehow due to the
+fact that the two regions acted simultaneously in the first instance,
+when the sight of the person was accompanied by the hearing of his name.
+In other words, the centres, as a whole, will tend to act at any future
+moment in the same complex way in which they have acted in past moments.</p>
+
+<p>All this is valuable hypothesis so far as it goes, though it plainly
+leaves much unaccounted for. As to why this reinstatement of a total
+cerebral pulsation in consequence of the re-excitation of a portion of
+the same should be accompanied by the specific mode of consciousness
+which we call recollection of something past, it is perhaps unreasonable
+to ask of physiology any sort of explanation.<a name="FNanchor_114_114" id="FNanchor_114_114"></a><a href="#Footnote_114_114" class="fnanchor">[114]</a></p>
+
+<p>Thus far as to the general or essential characteristics of memory on its
+mental and its bodily side. But what we commonly mean by memory is, on
+its psychical side at least, much more than this. We do not say that we
+properly recollect a thing unless we are able to refer it to some more
+or less clearly defined region of the past, and to localize it in the
+succession of experiences making up our mental image of the past. In
+other words, though we may speak of an imperfect kind of recollection
+where this definite reference is<span class='pagenum'><a name="Page_239" id="Page_239">[Pg 239]</a></span> wanting, we mean by a perfect form of
+memory something which includes this reference.</p>
+
+<p>Without entering just now upon a full analysis of what this reference to
+a particular region of the past means, I may observe that it takes place
+by help of an habitual retracing of the past, or certain portions of it,
+that is to say, a regressive movement of the imagination along the lines
+of our actual experience. Setting out from the present moment, I can
+move regressively to the preceding state of consciousness, to the
+penultimate, and so on. The fact that each distinct mental state is
+continuous with the preceding and the succeeding, and in a certain sense
+overlaps these, makes any portion of our experience essentially a
+succession of states of consciousness, involving some rudimentary idea
+of time. And thus, whether I anticipate a future event or recall a past
+one, my imagination, setting out from the present moment, constructs a
+sequence of experiences of which the one particularly dwelt on is the
+other term or boundary. And our idea of the position of this last in
+time, like that of an object in space, is one of a relation to our
+present position, and is determined by the length of the sequence of
+experiences thus run over by the imagination.<a name="FNanchor_115_115" id="FNanchor_115_115"></a><a href="#Footnote_115_115" class="fnanchor">[115]</a> It may be added that
+since the imagination can much more easily follow the actual order of
+experience than conceive it as reversed, the retrospective act of memory
+naturally tends to complete itself by a return movement forwards from
+the remembered event to the present moment.<span class='pagenum'><a name="Page_240" id="Page_240">[Pg 240]</a></span></p>
+
+<p>In practice this detailed retracing of successive moments of mental life
+is confined to very recent experiences. If I try to localize in time a
+remote event, I am content with placing it in relation to a series of
+prominent events or landmarks which serves me as a rough scheme of the
+past. The formation of such a mnemonic framework is largely due to the
+needs of social converse, which proceeds by help of a common standard of
+reference. This standard is supplied by those objective, that is to say,
+commonly experienced regularities of succession which constitute the
+natural and artificial divisions of the years, seasons, months, weeks,
+etc. The habit of recurring to these fixed divisional points of the past
+renders a return of imagination to any one of them more and more easy. A
+man has a definite idea of "a year ago" which the child wants, just
+because he has had so frequently to execute that vague regressive
+movement by which the idea arises. And though, as our actual point in
+time moves forward, the relative position of any given landmark is
+continually changing, the change easily adapts itself to that scheme of
+time-divisions which holds good for any present point.</p>
+
+<p>Few of our recollections of remote events involve a definite reference
+to this system of landmarks. The recollections of early life are, in the
+case of most people, so far as they depend on individual memory, very
+vaguely and imperfectly localized. And many recent experiences which are
+said to be half forgotten, are not referred to any clearly assignable
+position in time. One may say that in average cases definite
+localization characterizes only such supremely<span class='pagenum'><a name="Page_241" id="Page_241">[Pg 241]</a></span> interesting personal
+experiences as spontaneously recur again and again to the mind. For the
+rest it is confined to those facts and events of general interest to
+which our social habits lead us repeatedly to go back.<a name="FNanchor_116_116" id="FNanchor_116_116"></a><a href="#Footnote_116_116" class="fnanchor">[116]</a></p>
+
+<p>The consciousness of personal identity is said to be bound up with
+memory. That is to say, I am conscious of a continuous permanent self
+under all the varying surface-play of the stream of consciousness, just
+because I can, by an act of recollection, bring together any two
+portions of this stream of experience, and so recognize the unbroken
+continuity of the whole. If this is so, it would seem to follow from the
+very fragmentary character of our recollections that our sense of
+identity is very incomplete. As we shall see presently, there is good
+reason to look upon, this consciousness of continuous personal existence
+as resting only in part on memory, and mainly on our independently
+formed representation of what has happened in the numberless and often
+huge lacun&aelig; of the past left by memory.</p>
+
+<p>Having thus a rough idea of the mechanism of memory to guide us, we may
+be able to investigate the illusions incident to the process.</p>
+
+
+<p class='center'><i>Illusions of Memory.</i></p>
+
+<p>By an illusion of memory we are to understand a false recollection or a
+wrong reference of an idea to<span class='pagenum'><a name="Page_242" id="Page_242">[Pg 242]</a></span> some region of the past. It might,
+perhaps, be roughly described as a wrong interpretation of a special
+kind of mental image, namely, what I have called a mnemonic image.</p>
+
+<p>Mnemonic illusion is thus distinct from mere forgetfulness or imperfect
+memory. To forget or be doubtful about a past event is one thing; to
+seem to ourselves to remember it when we afterwards find that the fact
+was otherwise than we represented it in the apparent act of recollection
+is another thing. Indistinctness of recollection, or the decay of
+memory, is, as we shall soon see, an important co-operant condition of
+mnemonic illusion, but does not constitute it, any more than haziness of
+vision or disease of the visual organ, though highly favourable to
+optical illusion, can be said to constitute it.</p>
+
+<p>We may conveniently proceed in our detailed examination of illusions of
+memory, by distinguishing between three facts which appear to be
+involved in every complete and accurate process of recollection. When I
+distinctly recall an event, I am immediately sure of three things: (1)
+that something did really happen to me; (2) that it happened in the way
+I now think; and (3) that it happened when it appears to have happened.
+I cannot be said to recall a past event unless I feel sure on each of
+these points. Thus, to be able to say that an event happened at a
+particular date, and yet unable to describe how it happened, means that
+I have a very incomplete recollection. The same is true when I can
+recall an event pretty distinctly, but fail to assign it its proper
+date. This being so, it follows that there are three possible open<span class='pagenum'><a name="Page_243" id="Page_243">[Pg 243]</a></span>ings,
+and only three, by which errors of memory may creep in. And, as a matter
+of fact, each of these openings will be found to let in one class of
+mnemonic illusion. Thus we have (1) false recollections, to which there
+correspond no real events of personal history; (2) others which
+misrepresent the manner of happening of the events; and (3) others which
+falsify the date of the events remembered.</p>
+
+<p>It is obvious, from a mere glance at this threefold classification, that
+illusions of memory closely correspond to visual illusions. Thus, class
+(1) may be likened to the optical illusions known as subjective
+sensations of light, or ocular spectra. Here we can prove that there is
+nothing actually seen in the field of vision, and that the semblance of
+a visible object arises from quite another source than that of ordinary
+external light-stimulation, and by what may be called an accident.
+Similarly, in the case of the first class of mnemonic illusions, we
+shall find that there is nothing actually recollected, but that the
+mnemonic spectra or phantoms of recollected objects can be accounted for
+in quite another way. Such illusions come nearest to hallucinations in
+the region of memory.</p>
+
+<p>Again, class (2) has its visual analogue in those optical illusions
+which depend on effects of haziness and of the action of refracting
+media interposed between the eye and the object; in which cases, though
+there is some real thing corresponding to the perception, this is seen
+in a highly defective, distorted, and misleading form. In like manner,
+we can say that the images of memory often get obscured, distorted, and
+otherwise altered when they have receded into the dim distance,<span class='pagenum'><a name="Page_244" id="Page_244">[Pg 244]</a></span> and are
+looked back upon through a long space of intervening mental experience.
+Finally, class (3) has its visual counterpart in erroneous perceptions
+of distance, as when, for example, owing to the clearness of the
+mountain atmosphere and the absence of intervening objects, the side of
+the Jungfrau looks to the inexperienced tourist at Wengernalp hardly
+further than a stone's throw. It will be found that when our memory
+falsifies the date of an event, the error arises much in the same way as
+a visual miscalculation of distance.</p>
+
+<p>This threefold division of illusions of memory is plainly a rather
+superficial one, and not based on distinctions of psychological nature
+or origin. In order to make our treatment of the subject scientific as
+well as popular, it will be necessary to introduce the distinction
+between the passive and the active factor under each head. It will be
+found, I think, without forcing the analogy too far, that here, as in
+the case of the illusions of perception and introspection, error is
+attributable now to misleading suggestion on the part of the mental
+content of the moment, now to a process of incorporating into this
+content a mental image not suggested by it, but existing independently.</p>
+
+<p>If we are to proceed as we did in the case of the illusions of sense,
+and take up the lower stages of error first of all, we shall need to
+begin with the third class of errors, those of localization in time, or
+of what may be called mnemonic perspective. It has been already observed
+that the definite localization of a mnemonic image is only an occasional
+accompaniment of what is loosely called recollection. Hence, error as<span class='pagenum'><a name="Page_245" id="Page_245">[Pg 245]</a></span>
+to the position of an event in the past chain of events would seem to
+involve the least degree of violation of the confidence which we are
+wont to repose in memory. After this, we may proceed to the discussion
+of the second class, which I may call distortions of the mnemonic
+picture. And, finally, we may deal with the most signal and palpable
+variety of error of memory, namely, the illusions which I have called
+mnemonic spectra.</p>
+
+
+<p class='center'><i>Illusions of Perspective:</i> A. <i>Definite Localization.</i></p>
+
+<p>In order to understand these errors of mnemonic perspective, we shall
+have to inquire more closely than we have yet done into the
+circumstances which customarily determine our idea of the degree of
+propinquity or of remoteness of a past event. And first of all, we will
+take the case of a complete act of recollection when the mind is able to
+travel back along an uninterrupted series of experiences to a definitely
+apprehended point. Here there would seem, at first sight, to be no room
+for error, since this movement of retrospective imagination may be said
+to involve a direct measurement of the distance, just as a sweep of the
+eye over the ground between a spectator and an object affords a direct
+measurement of the intervening space.</p>
+
+<p>Modern science, however, tells us that this mode of measurement is by no
+means the simple and accurate process which it at first seems to be. In
+point of fact, there is something like a constant error in all such
+retrospective measurement. Vierordt has proved experimentally, by making
+a person try to reproduce the<span class='pagenum'><a name="Page_246" id="Page_246">[Pg 246]</a></span> varying time-intervals between the
+strokes of the pendulum of a metronome, that when the interval is a very
+small one, we uniformly tend to exaggerate it in retrospection; when a
+large one, to regard it, on the contrary, as less than it actually
+was.<a name="FNanchor_117_117" id="FNanchor_117_117"></a><a href="#Footnote_117_117" class="fnanchor">[117]</a></p>
+
+<p>A mere act of reflection will convince any one that when he tries to
+conceive a very small interval, say a quarter of a second, he is likely
+to make it too great. On the other hand, when we try to conceive a year,
+we do not fully grasp the whole extent of the duration. This is proved
+by the fact that merely by spending more time over the attempt, and so
+recalling a larger number of the details of the period, we very
+considerably enlarge our first estimate of the duration. And this leads
+to great discrepancies in the appreciation of the relative magnitudes of
+past sections of time. Thus, as Wundt observes, though in retrospect
+both a month and a year seem too short, the latter is relatively much
+more shortened than the former.<a name="FNanchor_118_118" id="FNanchor_118_118"></a><a href="#Footnote_118_118" class="fnanchor">[118]</a></p>
+
+<p>The cause of this constant error in the mode of reproducing durations
+seems to be connected with the very nature of the reproductive act. It
+must be borne in mind that this act is itself, like the experience which
+it represents, a mental process, occupying time, and that consequently
+it may very possibly reflect its time-character on the resulting
+judgment. Thus, since it certainly takes more than a quarter of a second
+to pass in imagination from one impression to another, it may be that we
+tend to confound this duration with that which we try to represent.
+Similarly, the fact that<span class='pagenum'><a name="Page_247" id="Page_247">[Pg 247]</a></span> in the act of reproductive imagination we
+under-estimate a longer interval between two impressions, say those of
+the slow beats of a colliery engine, may be accounted for by the
+supposition that the imagination tends to pass from the one impression
+to the succeeding one too rapidly.<a name="FNanchor_119_119" id="FNanchor_119_119"></a><a href="#Footnote_119_119" class="fnanchor">[119]</a></p>
+
+<p>The gross misappreciation of duration of long periods of time, while it
+may illustrate the principle just touched on, clearly involves the
+effect of other and more powerful influences. A mere glance at what is
+in our mind when we recall such a period as a month or a year, shows
+that there is no clear concrete representation at all. Time, it has been
+often said, is known only so far as filled with concrete contents or
+conscious experiences, and a perfect imagination of any particular
+period of past time would involve a retracing of all the successive
+experiences which have gone to make up this section of our life. This, I
+need not say, never happens, both because, on the one hand, memory does
+not allow of a complete reproduction of any segment of our experience,
+and because, on the other hand, such an imaginative reproduction, even
+if possible, would clearly occupy as much time as the experience
+itself.<a name="FNanchor_120_120" id="FNanchor_120_120"></a><a href="#Footnote_120_120" class="fnanchor">[120]</a><span class='pagenum'><a name="Page_248" id="Page_248">[Pg 248]</a></span></p>
+
+<p>When I call up an image of the year just closing, what really happens is
+a rapid movement of imagination over a series of prominent events, among
+which the succession of seasons probably occupies the foremost place,
+serving, as I have remarked, as a framework for my retrospective
+picture. Each of the events which I thus run over is really a long
+succession of shorter experiences, which, however, I do not separately
+represent to myself. My imaginative reproduction of such a period is
+thus essentially a greatly abbreviated and symbolic mode of
+representation. It by no means corresponds to the visual imagination of
+a large magnitude, say that of the length of sea horizon visible at any
+one moment, which is complete in an instant, and quite independent of a
+successive imagination of its parts or details. It is essentially a very
+fragmentary and defective numerical idea, in which, moreover, the real
+quantitative value of the units is altogether lost sight of.</p>
+
+<p>Now, it seems to follow from this that there is something illusory in
+all our recallings of long periods of the past. It is by no means
+strictly correct to say that memory ever reinstates the past. It is more
+true to say that we see the past in retrospect as greatly foreshortened.
+Yet even this is hardly an accurate account of what takes place, since,
+when we look at an object foreshortened in perspective, we see enough to
+enable us imaginatively to reconstruct the actual size of the object,
+whereas in the case of time-perspective no such reconstruction is even
+indirectly possible.</p>
+
+<p>It is to be added that this constant error in time-reproduction is
+greater in the case of remote periods<span class='pagenum'><a name="Page_249" id="Page_249">[Pg 249]</a></span> than of near ones of the same
+length. Thus, the retrospective estimate of a duration far removed from
+the present, say the length of time passed at a particular school, is
+much more superficial and fragmentary than that of a recent
+corresponding period. So that the time-vista of the past is seen to
+answer pretty closely to a visible perspective in which the amount of
+apparent error due to foreshortening increases with the distance.</p>
+
+<p>In practice, however, this defect in the imagination of duration leads
+to no error. Although, as a concrete image answering to some definite
+succession of experiences a year is a gross misrepresentation, as a
+general concept implying a collection of a certain number of similar
+successions of experience it is sufficiently exact. That is to say,
+though we cannot imagine the <i>absolute</i> duration of any such cycle of
+experience, we can, by the simple device of conceiving certain durations
+as multiples of others, perfectly well compare different periods of
+times, and so appreciate their <i>relative</i> magnitudes.</p>
+
+<p>Leaving, then, this constant error in time-appreciation, we will pass to
+the variable and more palpable errors in the retrospective measurement
+of time. Each person's experience will have told him that in estimating
+the distance of a past event by a mere retrospective sense of duration,
+he is liable to extraordinary fluctuations of judgment. Sometimes when
+the clock strikes we are surprised at the rapidity of the hour. At other
+times the timepiece seems rather to have lagged behind its usual pace.
+And what is true of a short interval is still more true of longer
+intervals, as<span class='pagenum'><a name="Page_250" id="Page_250">[Pg 250]</a></span> months and years. The understanding of these fluctuations
+will be promoted by our brief glance at the constant errors in
+retrospective time-appreciation.</p>
+
+<p>And here it is necessary to distinguish between the sense of duration
+which we have during any period, and the retrospective sense which
+survives the period, for these do not necessarily agree. The former
+rests mainly on our prospective sense of time, whereas the latter must
+be altogether retrospective.<a name="FNanchor_121_121" id="FNanchor_121_121"></a><a href="#Footnote_121_121" class="fnanchor">[121]</a></p>
+
+<p>Our estimate of time as it passes is commonly said to depend on the
+amount of consciousness which we are giving to the fact of its
+transition. Thus, when the mind is unoccupied and suffering from
+<i>ennui</i>, we feel time to move sluggishly. On the other hand, interesting
+employment, by diverting the thoughts from time, makes it appear to move
+at a more rapid pace. This fact is shown in the common expressions which
+we employ, such as "to kill time," and the German <i>Langweile</i>.
+Similarly, it is said that when we are eagerly anticipating an event, as
+the arrival of a friend, the mere fact of dwelling on the interval makes
+it appear to swell out.<a name="FNanchor_122_122" id="FNanchor_122_122"></a><a href="#Footnote_122_122" class="fnanchor">[122]</a></p>
+
+<p>This view is correct in the main, and is seen, indeed, to follow from
+the great psychological principle that what we attend to exists for us
+more, has more reality, and so naturally seems greater than what we do
+not<span class='pagenum'><a name="Page_251" id="Page_251">[Pg 251]</a></span> attend to. At the same time, this principle must be supplemented by
+another consideration. Suppose that I am very desirous that time should
+not pass quickly. If, for example, I am enjoying myself or indulging in
+idleness, and know that I have to be off to keep a not very agreeable
+engagement in a quarter of an hour, time will seem to pass too rapidly;
+and this not because my thoughts are diverted from the fact of its
+transition, for, on the contrary, they are reverting to it more than
+they usually do, but because my wish to lengthen the interval leads me
+to represent the unwelcome moment as further off than it actually is, in
+other words, to construct an ideal representation of the period in
+contrast with which the real duration looks miserably short.</p>
+
+<p>Our estimate of duration, when it is over, depends less on this
+circumstance of having attended to its transition than on other
+considerations. Wundt, indeed, seems to think that the feeling
+accompanying the actual flow of time has no effect on the surviving
+subjective appreciation; but this must surely be an error, since our
+mental image of any period is determined by the character of its
+contents. Wundt says that when once a tedious waiting is over, it looks
+short because we instantly forget the feeling of tedium. My
+self-observation, as well as the interrogation of others, has satisfied
+me, on the contrary, that this feeling distinctly colours the
+retrospective appreciation. Thus, when waiting at a railway station for
+a belated train, I am distinctly aware that each quarter of an hour
+looks long, not only as it passes, but when it is over. In fact, I am
+disposed to express my feeling<span class='pagenum'><a name="Page_252" id="Page_252">[Pg 252]</a></span> as one of disappointment that only so
+short an interval has passed since I last looked at my watch.</p>
+
+<p>Nevertheless, I am ready to allow that, though a feeling of tedium, or
+the contrary feeling of irritation at the rapidity of time, will linger
+for an appreciable interval and colour the retrospective estimate of
+time, this backward view is chiefly determined by other considerations.
+As Wundt remarks, we have no sense of time's slowness during sleep, yet
+on waking we imagine that we have been dreaming for an immensely long
+period. This retrospective appreciation is determined by the number and
+the degree or intensity of the experiences, and, what comes very much to
+the same thing, by the amount of unlikeness, freshness, and
+discontinuity characterizing these experiences.</p>
+
+<p>Time, as I have already hinted, is known under the form of a succession
+of different conscious experiences. Unbroken uniformity would give us no
+sense of time, because it would give us no conscious experience at all.
+Strictly speaking, there is no such thing as a perfectly uniform mental
+state extending through an appreciable duration. In looking at one and
+the same object, even in listening to one and the same tone, I am in no
+two successive fractions of a second in exactly the same state of mind.
+Slight alterations in the strength of the sensation,<a name="FNanchor_123_123" id="FNanchor_123_123"></a><a href="#Footnote_123_123" class="fnanchor">[123]</a> in the degree
+or direction of attention, and in the composition of that penumbra of
+vague images which it calls up, occur at every distinguishable fraction
+of time.<span class='pagenum'><a name="Page_253" id="Page_253">[Pg 253]</a></span></p>
+
+<p>This being so, it would seem to follow that the greater the number of
+clearly marked changes, and the more impressive and exciting these
+transitions, the fuller will be our sense of time. And this is borne out
+by individual reflection. When striking and deeply interesting events
+follow one another very rapidly, as when we are travelling, duration
+appears to swell out.</p>
+
+<p>It is possible that such a succession of stirring experiences may beget
+a vague consciousness of time at each successive moment, and apart from
+retrospection, simply by force of the change. In other words, without
+our distinctly attending to time, a series of novel impressions might,
+by giving us the consciousness of change, make us dimly aware of the
+numerical richness of our experiences. But, however this be, there is no
+doubt that, in glancing back on such a succession of exciting
+transitions of mental condition, time appears to expand enormously, just
+as it does in looking back on our dream-experience, or that rapid series
+of intensified feelings which, according to De Quincey and others, is
+produced by certain narcotics.</p>
+
+<p>The reason of this is plain. Such a type of successive experience offers
+to the retrospective imagination a large number of distinguishable
+points, and since this mode of estimating time depends, as we have seen,
+on the extent of the process of filling in, time will necessarily appear
+long in this case. On the other hand, when we have been engaged in very
+ordinary pursuits, in which few deeply interesting or exciting events
+have impressed themselves on memory, our retrospective picture will
+necessarily be very much of a blank,<span class='pagenum'><a name="Page_254" id="Page_254">[Pg 254]</a></span> and consequently the duration of
+the period will seem to be short.</p>
+
+<p>I observed that this retrospective appreciation of time depended on the
+degree of connection between the successive experiences. This condition
+is very much the same as the other just given, namely, the degree of
+uniformity of the experiences, since the more closely the successive
+stages of the experience are connected&mdash;as when, for example, we are
+going through our daily routine of work&mdash;the more quiet and unexciting
+will be the transition from each stage to its succeeding one. And on the
+other hand, all novelty of impression and exciting transition of
+experience clearly involves a want of connection. Wundt thinks the
+retrospective estimate of a connected series of experiences, such as
+those of our daily round of occupations, is defective just because the
+effort of attention, which precedes even an imaginative reproduction of
+an impression, so quickly accommodates itself in this case to each of
+the successive steps, whereas, when the experiences to be recalled are
+disconnected, the effort requires more time. In this way, the estimate
+of a past duration would be coloured by the sense of time accompanying
+the reproductive process itself. This may very likely be the case, yet I
+should be disposed to attach most importance to the number of
+distinguishable items of experience recalled.</p>
+
+<p>Our representation of the position of a given event in the past is, as I
+have tried to show, determined by the movement of imagination in going
+back to it from the present. And this is the same thing as to say that
+it depends on our retrospective sense of the inter<span class='pagenum'><a name="Page_255" id="Page_255">[Pg 255]</a></span>vening space. That is
+to say, the sense of distance in time, as in space, is the recognition
+of a term to a movement. And just as the distance of an object will seem
+greater when there are many intervening objects affording points of
+measurement, than when there are none (as on the uniform surface of the
+sea), so the distance of an event will vary with the number of
+recognized intervening points.</p>
+
+<p>The appreciation of the distance of an event in time does not, however,
+wholly depend on the character of this movement of imagination. Just as
+the apparent distance of a visible object depends <i>inter alia</i> on the
+distinctness of the retinal impression, so the apparent temporal
+remoteness of a past event depends in part on the degree of intensity
+and clearness of the mnemonic image. This is seen even in the case of
+those images which we are able distinctly to localize in the
+time-perspective. For a series of exciting experiences intervening
+between the present and a past event appears not only <i>directly</i> to add
+to our sense of distance by constituting an apparently long interval,
+but <i>indirectly</i> to add to it by giving an unusual degree of faintness
+to the recalled image. An event preceding some unusually stirring series
+of experiences gets thrust out of consciousness by the very engrossing
+nature of the new experiences, and so tends to grow more faint and
+ghost-like than it would otherwise have done.</p>
+
+<p>The full force of this circumstance is best seen in the fact that a very
+recent event, bringing with it a deep mental shock and a rapid stirring
+of wide tracts of feeling and thought, may get to look old in a
+marvellously short space of time. An announcement of the<span class='pagenum'><a name="Page_256" id="Page_256">[Pg 256]</a></span> loss of a dear
+friend, when sudden and deeply agitating, will seem remote even after an
+hour of such intense emotional experience. And the same twofold
+consideration probably explains the well-known fact that a year seems
+much shorter to the adult than to the child. The novel and comparatively
+exciting impressions of childhood tend to fill out time in retrospect,
+and also to throw back remote events into a dimly discernible region.</p>
+
+<p>Now, this same circumstance, the degree of vividness or of faintness of
+the mnemonic image, is that which determines our idea of distance when
+the character of the intervening experiences produces no appreciable
+effect.<a name="FNanchor_124_124" id="FNanchor_124_124"></a><a href="#Footnote_124_124" class="fnanchor">[124]</a> This is most strikingly illustrated in those imperfect
+kinds of recollection in which we are unable to definitely localize the
+mnemonic image. To the consideration of these we will now turn.</p>
+
+
+<p class='center'><i>B. Indefinite Localization.</i></p>
+
+<p>Speaking roughly and generally, we may say that the vividness of an
+image of memory decreases in proportion as the distance of the event
+increases. And this is the rule which we unconsciously apply in
+determining distance in time. Nevertheless, this rule gives us by no
+means an infallible criterion of distance. The very fact that different
+people so often dispute about the dates and the order of past events
+experienced in common, shows pretty plainly that images of the<span class='pagenum'><a name="Page_257" id="Page_257">[Pg 257]</a></span> same age
+tend to arise in the mind with very unequal degrees of vividness.</p>
+
+<p>Sometimes pictures of very remote incidents may suddenly present
+themselves to our minds with a singular degree of brightness and force.
+And when this is the case, there is a disposition to think of them as
+near. If the relations of the event to other events preceding and
+succeeding it are not remembered, this momentary illusion will persist.
+We have all heard persons exclaim, "It seems only yesterday," under the
+sense of nearness which accompanies a recollection of a remote event
+when vividly excited. The most familiar instance of such lively
+reproduction is the feeling which we experience on revisiting the scene
+of some memorable event. At such a time the past may return with
+something of the insistence of a present perceived reality. In passing
+from place to place, in talking with others, and in reading, we are
+liable to the sudden return by hidden paths of association of images of
+incidents that had long seemed forgotten, and when they thus start up
+fresh and vigorous, away from their proper surroundings, they invariably
+induce a feeling of the propinquity of the events.</p>
+
+<p>In many cases we cannot say why these particular images, long buried in
+oblivion, should thus suddenly regain so much vitality. There seems,
+indeed, to be almost as much that is arbitrary and capricious in the
+selection by memory of its vivid images as in the selection of its
+images as a whole; and, this being so, it is plain that we are greatly
+exposed to the risk of illusion from this source.<span class='pagenum'><a name="Page_258" id="Page_258">[Pg 258]</a></span></p>
+
+<p>There is an opposite effect in the case of recent occurrences that, for
+some reason or another, have left but a faint impression on the memory;
+though this fact is not, perhaps, so familiar as the other. I met a
+friend, we will suppose, a few days since at my club, and we exchanged a
+few words. My mind was somewhat preoccupied at the time, and the
+occurrence did not stamp itself on my recollection. To-day I meet him
+again, and he reminds me of a promise I made him at the time. His
+reminder suffices to restore a dim image of the incident, but the fact
+of its dimness leads to the illusion that it really happened much longer
+ago, and it is only on my friend's strong assurances, and on reasoning
+from other data that it must have occurred the day he mentions, that I
+am able to dismiss the illusion.</p>
+
+<p>The most striking examples of the illusory effect of mere vividness,
+involving a complete detachment of the event from the prominent
+landmarks of the past, are afforded by public events which lie outside
+the narrower circle of our personal life, and which do not in the
+natural course of things become linked to any definitely localized
+points in the field of memory. These events may be very stirring and
+engrossing for the time, but in many cases they pass out of the mind
+just as suddenly as they entered it. We have no occasion to revert to
+them, and if by chance we are afterwards reminded of them, they are
+pretty certain to look too near, just because the fact of their having
+greatly interested us has served to render their images particularly
+vivid.</p>
+
+<p>A curious instance of this illusory effect was<span class='pagenum'><a name="Page_259" id="Page_259">[Pg 259]</a></span> supplied not long since
+by the case of the ex-detectives, the expiration of whose term of
+punishment (three years) served as an occasion for the newspapers to
+recall the event of their trial and conviction. The news that three
+years had elapsed since this well-remembered occurrence proved very
+startling to myself, and to a number of my friends, all of us agreeing
+that the event did not seem to be at more than a third of its real
+distance. More than one newspaper commented on the apparent rapidity of
+the time, and this shows pretty plainly that there was some cause at
+work, such as I have suggested, producing a common illusion.</p>
+
+<p>I have treated of these illusions connected with the estimate of past
+time and the dating of past events as passive illusions, not involving
+any active predisposition on the part of the imagination. At the same
+time, it is possible that error in these matters may occasionally depend
+on a present condition of the feelings and the imagination. It seems
+plain that since the apparent degree of remoteness of an event not
+distinctly localized in the past varies inversely as the degree of
+vividness of the mnemonic image, any conscious concentration of mind on
+a recollection will tend to bring it too near. In this way, then, an
+illusory propinquity may be given to a recalled event through a mere
+desire to dwell on it, or even a capricious wish to deceive one's self.</p>
+
+<p>When, for example, old friends come together and talk over the days of
+yore, there is a gradual reinstatement of seemingly lost experiences,
+which often partakes of the character of a semi-voluntary process of
+self-delusion. Through the cumulative effect of mutual<span class='pagenum'><a name="Page_260" id="Page_260">[Pg 260]</a></span> reminder,
+incident after incident returns, adding something to the whole picture
+till it acquires a degree of completeness, coherence, and vividness that
+render it hardly distinguishable from a very recent experience. The
+process is like looking at a distant object through a field-glass.
+Mistiness disappears, fresh details come into view, till we seem to
+ourselves to be almost within reach of the object.</p>
+
+<p>Where the mind habitually goes back to some painful circumstance under
+the impulse of a morbid disposition to nurse regret, this momentary
+illusion may become recurring, and amount to a partial confusion of the
+near and the remote in our experience. An injury long brooded on seems
+at length a thing that continually moves forward as we move; it always
+presents itself to our memories as a very recent event. In states of
+insanity brought on by some great shock, we see this morbid tendency to
+resuscitate the dead past fully developed, and remote events and
+circumstances becoming confused with present ones.</p>
+
+<p>On the other hand, in more healthy states of mind there presents itself
+an exactly opposite tendency, namely, an impulse of the will to banish
+whatever when recalled gives pain to the furthest conceivable regions of
+the past. Thus, when we have lost something we cherished dearly, and the
+recollection of it brings fruitless longing, we instinctively seek to
+expel the recollection from our minds. The very feeling that what has
+been can never again be, seems to induce this idea of a vast remoteness
+of the vanished reality. When, moreover, the lost object was fitted to
+call forth the emotion of reverence, the impulse to magnify the<span class='pagenum'><a name="Page_261" id="Page_261">[Pg 261]</a></span>
+remoteness of the loss may not improbably be reinforced by the
+circumstance that everything belonging to the distant past is fitted on
+that account to excite a feeling akin to reverence. So, again, any
+rupture in our mental development may lead us to exaggerate the distance
+of some past portion of our experience. When we have broken with our
+former selves, either in the way of worsening or bettering, we tend to
+project these further into the past.</p>
+
+<p>It is only when the sting of the recollection is removed, when, for
+example, the calling up of the image of a lost friend is no longer
+accompanied with the bitterness of futile longing, that a healthy mind
+ventures to nourish recollections of such remote events and to view
+these as part of its recent experiences. In this case the mnemonic image
+becomes transformed into a kind of present emotional possession, an
+element of that idealized and sublimated portion of our experience with
+which all imaginative persons fill up the emptiness of their actual
+lives, and to which the poet is wont to give an objective embodiment in
+his verse.</p>
+
+
+<p class='center'><i>Distortions of Memory.</i></p>
+
+<p>It is now time to pass to the second group of illusions of memory,
+which, according to the analogy of visual errors, may be called
+atmospheric illusions. Here the degree of error is greater than in the
+case of illusions of time-perspective, since the very nature of the
+events or circumstances is misconceived. We do not recall the event as
+it happened, but see it in part only, and obscured, or bent and
+distorted as by a<span class='pagenum'><a name="Page_262" id="Page_262">[Pg 262]</a></span> process of refraction. Indeed, this transformation of
+the past does closely correspond with the transformation of a visible
+object effected by intervening media. Our minds are such refracting
+media, and the past reappears to us not as it actually was when it was
+close to us, but in numerous ways altered and disguised by the
+intervening spaces of our conscious experience.</p>
+
+<p>To begin with, what we call recollection is uniformly a process of
+softening the reality. When we appear to ourselves to realize events of
+the remote past, it is plain that our representation in a general way
+falls below the reality: the vividness, the intensity of our impressions
+disappears. More particularly, so far as our experiences are emotional,
+they tend thus to become toned down by the mere lapse of time and the
+imperfections of our reproductive power. That which we seem to see in
+the act of recollection is thus very different from the reality.</p>
+
+<p>Not only is there this general deficiency in mnemonic representation,
+there are special deficiencies due to the fact of oblivescence. Our
+memories restore us only fragments of our past life. And just as objects
+seen imperfectly at a great distance may assume a shape quite unlike
+their real one, so an inadequate representation of a past event by
+memory often amounts to misrepresentation. When revisiting a place that
+we have not seen for many years, we are apt to find that our
+recollection of it consisted only of some insignificant details, which
+arranged themselves in our minds into something oddly unlike the actual
+scene. So, too, some accidental accompaniment of an incident in early
+life is preserved, as though it were the main<span class='pagenum'><a name="Page_263" id="Page_263">[Pg 263]</a></span> feature, serving to give
+quite a false colouring to the whole occurrence.</p>
+
+<p>It seems quite impossible to account for these particular survivals,
+they appear to be so capricious. When a little time has elapsed after an
+event, and the attendant circumstances fade away from memory, it is
+often difficult to say why we were impressed with it as we afterwards
+prove to have been. It is no doubt possible to see that many of the
+recollections of our childhood owe their vividness to the fact of the
+exceptional character of the events; but this cannot always be
+recognized. Some of them seem to our mature minds very oddly selected,
+although no doubt there are in every case good reasons, if we could only
+discover them, why those particular incidents rather than any others
+should have been retained.</p>
+
+<p>The liability to error resulting from mere oblivescence and the
+arbitrary selection of mental images is seen most plainly, perhaps, in
+our subsequent representation and estimate of whole periods of early
+life. Our idea of any stage of our past history, as early childhood, or
+school days, is built up out of a few fragmentary intellectual relics
+which cannot be certainly known to answer to the most important and
+predominant experiences of the time. When, for example, we try to decide
+whether our school days were our happiest days, as is so often alleged,
+it is obvious that we are liable to fall into illusion through the
+inadequacy of memory to preserve characteristic or typical features, and
+none but these. We cannot easily recall the ordinary every-day level of
+feeling of a distant period of life, but rather think of exceptional
+moments of rejoicing or depression.<span class='pagenum'><a name="Page_264" id="Page_264">[Pg 264]</a></span> The ordinary man's idea of the
+emotional experience of his school days is probably built up out of a
+few scrappy recollections of extraordinary and exciting events, such as
+unexpected holidays, success in the winning of prizes, famous "rows"
+with the masters, and so on.</p>
+
+<p>Besides the impossibility of getting at the average and prevailing
+mental tone of a distant section of life, there is a special difficulty
+in determining the degree of happiness of the past, arising from the
+fact that our memory for pleasures and for pains may not be equally
+good. Most people, perhaps, can recall the enjoyments of the past much
+more vividly than the sufferings. On the other hand, there seem to be
+some who find the retention of the latter the easier of the two. This
+fact should not be forgotten in reading the narrative of early hardships
+which some recent autobiographies have given us.</p>
+
+<p>Not only does our idea of the past become inexact by the mere decay and
+disappearance of essential features, it becomes positively incorrect
+through the gradual incorporation of elements that do not properly
+belong to it. Sometimes it is easy to see how these extraneous ideas get
+imported into our mental representation of a past event. Suppose, for
+example, that a man has lost a valuable scarf-pin. His wife suggests
+that a particular servant, whose reputation does not stand too high, has
+stolen it. When he afterwards recalls the loss, the chances are that he
+will confuse the fact with the conjecture attached to it, and say he
+remembers that this particular servant did steal the pin. Thus, the past
+activity of imagination serves to corrupt and partially falsify
+recollections that have a genuine basis of fact.<span class='pagenum'><a name="Page_265" id="Page_265">[Pg 265]</a></span></p>
+
+<p>It is evident that this class of mnemonic illusions approximates in
+character to illusions of perception. When the imagination supplies the
+interpretation at the very time, and the mind reads this into the
+perceived object, the error is one of perception. When the addition is
+made afterwards, on reflecting upon the perception, the error is one of
+memory. The "fallacies of testimony" which depend on an adulteration of
+pure observation with inference and conjecture, as, for example, the
+inaccurate and wild statements of people respecting their experiences at
+spiritualist <i>s&eacute;ances</i>, while they illustrate the curious blending of
+both kinds of error, are probably much oftener illusions of memory than
+of perception.<a name="FNanchor_125_125" id="FNanchor_125_125"></a><a href="#Footnote_125_125" class="fnanchor">[125]</a></p>
+
+<p>Although in many cases we can account to ourselves for this confusion of
+fact and imagination, in other cases it is difficult to see any close
+relation between the fact remembered and the foreign element imported
+into it. An idea of memory seems sometimes to lose its proper moorings,
+so to speak; to drift about helplessly among other ideas, and finally,
+by some chance, to hook itself on to one of these, as though it
+naturally belonged to it. Anybody who has had an opportunity of
+carefully testing the truthfulness of his recollection of some remote
+event in early life will have found how oddly extraneous elements become
+incorporated into the memorial picture. Incidents get put into wrong
+places, the wrong persons are introduced into a scene, and so on. Here
+again we may illustrate the mnemonic illusion by a visual one. When a
+tree standing before or behind a house and projecting above or to<span class='pagenum'><a name="Page_266" id="Page_266">[Pg 266]</a></span> the
+side of it is not sharply distinguished from the latter, it may serve to
+give it a very odd appearance.</p>
+
+<p>These confusions of the mental image may arise even when only a short
+interval has elapsed. In the case of many of the fleeting impressions
+that are only half recollected, this kind of error is very easy. Thus,
+for example, I may have lent a book to a friend last week. I really
+remember the act of lending it, but have forgotten the person. But I am
+not aware of this. The picture of memory has unknowingly to myself been
+filled up by this unconscious process of shifting and rearrangement, and
+the idea of another person has by some odd accident got substituted for
+that of the real borrower. If we could go deeply enough into the matter,
+we should, of course, be able to explain why this particular confusion
+arose. We might find, for example, that the two persons were associated
+in my mind by a link of resemblance, or that I had dealings with the
+other person about the same time. Similarly, when we manage to join an
+event to a wrong place, we may find that it is because we heard of the
+occurrence when staying at the particular locality, or in some other way
+had the image of the place closely associated in our minds with the
+event. But often we are wholly unable to explain the displacement.</p>
+
+<p>So far I have been speaking of the passive processes by which the past
+comes to wear a new face to our imaginations. In these our present
+habits of feeling and thinking take no part; all is the work of the
+past, of the decay of memory, and the gradual confusion of images. This
+process of disorganization may be likened to the action of damp on some
+old manuscript,<span class='pagenum'><a name="Page_267" id="Page_267">[Pg 267]</a></span> obliterating some parts, altering the appearance of
+others, and even dislocating certain portions. Besides this passive
+process of transformation, there is a more active one in which our
+present minds co-operate. In memory, as in perception and introspection,
+there is a process of preparation or preadjustment of mind, and here
+will be found room for what I had called active error. This may be
+illustrated by the operation of "interpreting" an old manuscript which
+has got partially obliterated, or of "restoring" a faded picture; in
+each of which operations error will be pretty sure to creep in through
+an importation of the restorer's own ideas into the relic of the past.</p>
+
+<p>Just as when distant objects are seen mistily our imaginations come into
+play, leading us to fancy that we see something completely and
+distinctly, so when the images of memory become dim, our present
+imagination helps to restore them, putting a new patch into the old
+garment. If only there is some relic of the past event preserved, a bare
+suggestion of the way in which it may have happened will often suffice
+to produce the conviction that it actually did happen in this way. The
+suggestions that naturally arise in our minds at such times will bear
+the stamp of our present modes of experience and habits of thought.
+Hence, in trying to reconstruct the remote past, we are constantly in
+danger of importing our present selves into our past selves.</p>
+
+<p>The kind of illusion of memory which thus depends on the spontaneous or
+independent activity of present imagination is strikingly illustrated in
+the curious cases of mistaken identity with which the proceedings<span class='pagenum'><a name="Page_268" id="Page_268">[Pg 268]</a></span> of
+our law courts supply us from time to time. When a witness in good
+faith, but erroneously, affirms that a man is the same as an old
+acquaintance of his, we may feel sure that there is some striking point
+or points of similarity between the two persons. But this of itself
+would only partly account for the illusion, since we often see new faces
+that, by a number of curious points of affinity, call up in a
+tantalizing way old and familiar ones. What helps in this case to
+produce the illusion is the preconception that the present man is the
+witness's old friend. That is to say, his recollection is partly true,
+though largely false. He does really recall the similar feature,
+movement, or tone of voice; he only seems to himself to recall the rest
+of his friend's appearance; for, to speak correctly, he projects the
+present impression into the past, and constructs his friend's face out
+of elements supplied by the new one. Owing to this cause, an illusion of
+memory is apt to multiply itself, one man's assertion of what happened
+producing by contagion a counterfeit of memory's record in other minds.</p>
+
+<p>I said just now that we tend to project our present modes of experience
+into the past. We paint our past in the hues of the present. Thus we
+imagine that things which impressed us in some remote period of life
+must answer to what is impressive in our present stage of mental
+development. For example, a person recalls a hill near the home of his
+childhood, and has the conviction that it was of great height. On
+revisiting the place he finds that the eminence is quite insignificant.
+How can we account for this? For one thing, it is to be observed that to
+his undeveloped<span class='pagenum'><a name="Page_269" id="Page_269">[Pg 269]</a></span> childish muscles the climbing to the top meant a
+considerable expenditure of energy, to be followed by a sense of
+fatigue. The man remembers these feelings, and "unconsciously reasoning"
+by present experience, that is to say, by the amount of walking which
+would now produce this sense of fatigue, imagines that the height was
+vastly greater than it really was. Another reason is, of course, that a
+wider knowledge of mountains has resulted in a great alteration of the
+man's standard of height.</p>
+
+<p>From this cause arises a tendency generally to exaggerate the
+impressions of early life. Youth is the period of novel effects, when
+all the world is fresh, and new and striking impressions crowd in
+thickly on the mind. Consequently, it takes much less to produce a given
+amount of mental excitation in childhood than in after-life. In looking
+back on this part of our history, we recall for the most part just those
+events and scenes which deeply stirred our minds by their strangeness,
+novelty, etc., and so impressed themselves on the tablet of our memory;
+and it is this sense of something out of the ordinary beat that gives
+the characteristic colour to our recollection. In other words, we
+remember something as wonderful, admirable, exceptionally delightful,
+and so on, rather than as a definitely imagined event. This being so, we
+unconsciously transform the past occurrence by reasoning from our
+present standard of what is impressive. Who has not felt an unpleasant
+disenchantment on revisiting some church, house, or park that seemed a
+wondrous paradise to his young eyes? All our feelings are capable of
+leading us into this kind of illusion. What<span class='pagenum'><a name="Page_270" id="Page_270">[Pg 270]</a></span> seemed beautiful or awful
+to us as children, is now pictured in imagination as corresponding to
+what moves our mature minds to delight or awe. One cannot help wondering
+what we should think of our early heroes or heroines if we could see
+them again with our adult eyes exactly as they were.</p>
+
+<p>While the past may thus take on an illusory hue through the very
+progress of our experience and our emotional life, it may become further
+transformed by a more conscious process, namely, the idealizing touch of
+a present feeling. The way in which the emotions of love, reverence, and
+so on, thus transform their lost objects is too well known to need
+illustration. Speaking generally, we may say that in healthy minds the
+play of these impulses of feeling results in a softening of the harsher
+features of the past, and in an idealization of its happier and brighter
+aspects. As Wordsworth says, we may assign to Memory a pencil&mdash;</p>
+
+<p>
+<span style="margin-left: 1em;">"That, softening objects, sometimes even</span><br />
+<span style="margin-left: 2.3em;">Outstrips the heart's demand;</span><br />
+<br />
+<span style="margin-left: 1em;">"That smoothes foregone distress, the lines</span><br />
+<span style="margin-left: 2.3em;">Of lingering care subdues,</span><br />
+<span style="margin-left: 1.5em;">Long-vanished happiness refines,</span><br />
+<span style="margin-left: 2.3em;">And clothes in brighter hues."<a name="FNanchor_126_126" id="FNanchor_126_126"></a><a href="#Footnote_126_126" class="fnanchor">[126]</a></span><br />
+</p>
+
+<p>Enough has now been said, perhaps, to show in how many ways our
+retrospective imagination transforms the actual events of our past life.
+So thoroughly, indeed, do the relics of this past get shaken together in
+new kaleidoscopic combinations, so much of the<span class='pagenum'><a name="Page_271" id="Page_271">[Pg 271]</a></span> result of later
+experiences gets imported into our early years, that it may well be
+asked whether, if the record of our actual life were ever read out to
+us, we should be able to recognize it. It looks as though we could be
+sure of recalling only recent events with any degree of accuracy and
+completeness. As soon as they recede at any considerable distance from
+us, they are subject to a sort of atmospheric effect. Much grows
+indistinct and drops altogether out of sight, and what is still seen
+often takes a new and grotesquely unlike shape. More than this, the play
+of fancy, like the action of some refracting medium, bends and distorts
+the outlines of memory's objects, making them wholly unlike the
+originals.</p>
+
+
+<p class='center'><i>Hallucinations of Memory.</i></p>
+
+<p>We will now go on to the third class of mnemonic error, which I have
+called the spectra of memory, where there is not simply a transformation
+of the past event, but a complete imaginative creation of it. This class
+of error corresponds, as I have observed, to an hallucination in the
+region of sense-perception. And just as we distinguished between those
+hallucinations of sense which arise first of all through some
+peripherally caused subjective sensation, and those which want even this
+element of reality and depend altogether on the activity of imagination,
+so we may mark off two classes of mnemonic hallucination. The false
+recollection may correspond to something past&mdash;and to this extent be a
+recollection&mdash;though not to any objective fact, but only to a subjective
+representation of such a fact, as, for example, a dream. In<span class='pagenum'><a name="Page_272" id="Page_272">[Pg 272]</a></span> this case
+the imitation of the mnemonic process may be very definite and complete.
+Or the false recollection may be wholly a retrojection of a present
+mental image, and so by no stretch of language be deserving of the name
+recollection.</p>
+
+<p>It is doubtful whether by any effort of will a person could bring
+himself to regard a figment of his present imagination as representative
+of a past reality. Definite and complete hallucinations of this sort do
+not in normal circumstances arise. It seems necessary for a complete
+illusion of memory that there should be something past and recovered at
+the moment, though this may not be a real personal experience.<a name="FNanchor_127_127" id="FNanchor_127_127"></a><a href="#Footnote_127_127" class="fnanchor">[127]</a> On
+the other hand, it is possible, as we shall presently see, under certain
+circumstances, to create out of present materials, and in a vague and
+indefinite shape, pure phantoms of past experience, that is to say,
+quasi-mnemonic images to which there correspond no past occurrences
+whatever.</p>
+
+<p>All recollection, as we have seen, takes place by means of a present
+mental image which returns with a certain degree of vividness, and is
+instantaneously identified with some past event. In many cases this
+instinctive process of identification proves to be legitimate, for, as a
+matter of fact, real impressions<span class='pagenum'><a name="Page_273" id="Page_273">[Pg 273]</a></span> are the first and the commonest source
+of such lively mnemonic images. But it is not always so. There are other
+sources of our mental imagery which compete, so to speak, with the
+region of real personal experience. And sometimes these leave behind
+them a vivid image having all the appearance of a genuine mnemonic
+image. When this is so, it is impossible by a mere introspective glance
+to detect the falsity of the message from the past. We are in the same
+position as the purchaser in a jet market, where a spurious commodity
+has got inextricably mixed up with the genuine, and there is no ready
+criterion by which he can distinguish the true from the false. Such a
+person, if he purchases freely, is pretty sure to make a number of
+mistakes. Similarly, all of us are liable to take counterfeit mnemonic
+images for genuine ones; that is to say, to fall into an illusion of
+"recollecting" what never really took place.</p>
+
+<p>But what, it may be asked, are these false and illegitimate sources of
+mnemonic images, these unauthorized mints which issue a spurious mental
+coinage, and so confuse the genuine currency? They consist of two
+regions of our internal mental life, which most closely resemble the
+actual perception of real things in vividness and force, namely,
+dream-consciousness and waking imagination. Each of these may introduce
+into the mind vivid images which afterwards tend, under certain
+circumstances, to assume the guise of recollections of actual events.</p>
+
+<p>That our dream-experience may now and again lead us into illusory
+recollection has already been hinted. And it is easy to understand why
+this is so.<span class='pagenum'><a name="Page_274" id="Page_274">[Pg 274]</a></span> When dreaming we have, as we have seen, a mental experience
+which closely approximates in intensity and reality to that of waking
+perception. Consequently, dreams may leave behind them, for a time,
+vivid images which simulate the appearance of real images of memory.
+Most of us, perhaps, have felt this after-effect of dreaming on our
+waking thoughts. It is sometimes very hard to shake off the impression
+left by a vivid dream, as, for example, that a dead friend has returned
+to life. During the day that follows the dream, we have at intermittent
+moments something like an assurance that we have seen our lost friend;
+and though we immediately correct the impression by reflecting that we
+are recalling but a dream, it tends to revive within us with a strange
+pertinacity.</p>
+
+<p>In addition to this proximate effect of a dream in disturbing the normal
+process of recollection, there is reason to suppose that dreams may
+exert a more remote effect on our memories. So widely different in its
+form is our dreaming from our waking experience, that our dreams are
+rarely recalled as wholes with perfect distinctness. They revive in us
+only as disjointed fragments, and only for brief moments when some
+accidental resemblance in the present happens to stir the latent trace
+they have left on our minds. We get sudden flashes out of our
+dream-world, and the process is too rapid, too incomplete for us to
+identify the region whence the flashes come.</p>
+
+<p>It is highly probable that our dreams are, to a large extent, answerable
+for the sense of familiarity that we sometimes experience in visiting a
+new locality<span class='pagenum'><a name="Page_275" id="Page_275">[Pg 275]</a></span> or in seeing a new face. If, as we have found some of the
+best authorities saying, we are, when asleep, always dreaming more or
+less distinctly, and if, as we know, dreaming is a continual process of
+transformation of our waking impressions in new combinations, it is not
+surprising that our dreams should sometimes take the form of forecasts
+of our waking life, and that consequently objects and scenes of this
+life never before seen should now and again wear a familiar look.</p>
+
+<p>That some instances of this puzzling sense of familiarity can be
+explained in this way is proved. Thus, Paul Radestock, in the work
+<i>Schlaf und Traum</i>, already quoted, tells us: "When I have been taking a
+walk, with my thoughts quite unfettered, the idea has often occurred to
+me that I had seen, heard, or thought of this or that thing once before,
+without being able to recall when, where, and in what circumstances.
+This happened at the time when, with a view to the publication of the
+present work, I was in the habit of keeping an exact record of my
+dreams. Consequently, I was able to turn to this after these
+impressions, and on doing so I generally found the conjecture confirmed
+that I had previously dreamt something like it." Scientific inquiry is
+often said to destroy all beautiful thoughts about nature and life; but
+while it destroys it creates. Is it not almost a romantic idea that just
+as our waking life images itself in our dreams, so our dream-life may
+send back some of its shadowy phantoms into our prosaic every-day world,
+touching this with something of its own weird beauty?</p>
+
+<p>Not only may dreams beget these momentary illusions of memory, they may
+give rise to something<span class='pagenum'><a name="Page_276" id="Page_276">[Pg 276]</a></span> like permanent illusions. If a dream serves to
+connect a certain idea with a place or person, and subsequent experience
+does not tend to correct this, we may keep the belief that we have
+actually witnessed the event. And we may naturally expect that this
+result will occur most frequently in the case of those who habitually
+dream vividly, as young children.</p>
+
+<p>It seems to me that many of the quaint fancies which children get into
+their heads about things they hear of arise in this way. I know a person
+who, when a child, got the notion that when his baby-brother was weaned,
+he was taken up on a grassy hill and tossed about. He had a vivid idea
+of having seen this curious ceremony. He has in vain tried to get an
+explanation of this picturesque rendering of an incident of babyhood
+from his friends, and has come to the conclusion that it was the result
+of a dream. If, as seems probable, children's dreams thus give rise to
+subsequent illusions of memory, the fact would throw a curious light on
+some of the startling quasi-records of childish experience to be met
+with in autobiographical literature.</p>
+
+<p>Odd though it may at first appear, old age is said to resemble youth in
+this confusion of dream-recollection with the memory of waking
+experience. Dr. Carpenter<a name="FNanchor_128_128" id="FNanchor_128_128"></a><a href="#Footnote_128_128" class="fnanchor">[128]</a> tells us of "a lady of advanced age
+who ... continually dreams about passing events, and seems entirely unable
+to distinguish between her dreaming and her waking experiences,
+narrating the former with implicit belief in them, and giving directions
+based on them." This confusion in the case<span class='pagenum'><a name="Page_277" id="Page_277">[Pg 277]</a></span> of the old may possibly
+arise not from an increase in the intensity of the dreams, but from a
+decrease in the intensity of the waking impressions. As Sir Henry
+Holland remarks,<a name="FNanchor_129_129" id="FNanchor_129_129"></a><a href="#Footnote_129_129" class="fnanchor">[129]</a> in old age life approaches to the state of a
+dream.</p>
+
+<p>The other source of what may, by analogy with the hallucinations of
+sense, be called the peripherally originating spectra of memory is
+waking imagination. In certain morbid conditions of mind, and in the
+case of the few healthy minds endowed with special imaginative force,
+the products of this mental activity, may, as we saw when dealing with
+illusions of perception, closely resemble dreams in their vividness and
+apparent actuality. When this is the case, illusions of memory may arise
+at once just as in the case of dreams. This will happen more easily when
+the imagination has for some time been occupied with the same group of
+ideal scenes, persons, or events. To Dickens, as is well known, his
+fictitious characters were for the time realities, and after he had
+finished his story their forms and their doings lingered with him,
+assuming the aspect of personal recollections. So, too, the energetic
+activity of imagination which accompanies a deep and absorbing sympathy
+with another's painful experiences, may easily result in so vivid a
+realization of all their details as to leave an after-sense of
+<i>personal</i> suffering. All highly sympathetic persons who have closely
+accompanied beloved friends through a great sorrow have known something
+of this subsequent feeling.</p>
+
+<p>The close connection and continuity between nor<span class='pagenum'><a name="Page_278" id="Page_278">[Pg 278]</a></span>mal and abnormal states
+of mind is illustrated in the fact that in insanity the illusion of
+taking past imaginations for past realities becomes far more powerful
+and persistent. Abercrombie (<i>Intellectual Powers</i>, Part III. sec. iv. &sect;
+2, "Insanity") speaks of "visions of the imagination which have formerly
+been indulged in of that kind which we call waking dreams or
+castle-building recurring to the mind in this condition, and now
+believed to have a real existence." Thus, for example, one patient
+believed in the reality of the good luck previously predicted by a
+fortune-teller. Other writers on mental disease observe that it is a
+common thing for the monomaniac to cherish the delusion that he has
+actually gained the object of some previous ambition, or is undergoing
+some previously dreaded calamity.</p>
+
+<p>Nor is it necessary to these illusions of memory that there should be
+any exceptional force of imagination. A fairly vivid representation to
+ourselves of anything, whether real or fictitious, communicated by
+others, will often result in something very like a personal
+recollection. In the case of works of history and fiction, which adopt
+the narrative tense, this tendency to a subsequent illusion of memory is
+strengthened by the disposition of the mind at the moment of reading to
+project itself backwards as in an act of recollection. This is a point
+which will be further dealt with in the next chapter.</p>
+
+<p>In most cases, however, illusions of memory growing out of previous
+activities of the imagination appear only after the lapse of some time,
+when in the natural course of things the mental images derived from
+actual ex<span class='pagenum'><a name="Page_279" id="Page_279">[Pg 279]</a></span>perience would sink to a certain degree of faintness. Habitual
+novel-readers often catch themselves mistaking the echo of some passage
+in a good story for the trace left by an actual event. A person's name,
+a striking saying, and even an event itself, when we first come across
+it or experience it, may for a moment seem familiar to us, and to recall
+some past like impression, if it only happens to resemble something in
+the works of a favourite novelist. And so, too, any recital of another's
+experience, whether oral or literary, if it deeply interests us and
+awakens a specially vivid imagination of the events described, may
+easily become the starting-point of an illusory recollection.</p>
+
+<p>Children are in the habit of "drinking in" with their vigorous and eager
+imaginations what is told them and read to them, and hence they are
+specially likely to fall into this kind of error. Not only so: when they
+grow up and their early recollections lose their definiteness, becoming
+a few fragments saved from a lost past, it must pretty certainly happen
+that if any ideas derived from these recitals are preserved, they will
+simulate the form of memories. Thus, I have often caught myself for a
+moment under the sway of the illusion that I actually visited the
+Exhibition of 1851, the reason being that I am able to recall the
+descriptions given to me of it by my friends, and the excitement
+attending their journey to London on the occasion. It is to be added
+that repetition of the act of imagination will tend still further to
+deepen the subsequent feeling that we are recollecting something. As
+Hartley well observes, a man, by repeating a story, easily comes to
+suppose that he remembers it.<a name="FNanchor_130_130" id="FNanchor_130_130"></a><a href="#Footnote_130_130" class="fnanchor">[130]</a><span class='pagenum'><a name="Page_280" id="Page_280">[Pg 280]</a></span></p>
+
+<p>Here, then, we have another source of error that we must take into
+account in judging of the authenticity of an autobiographical narration
+of the events of childhood. The more imaginative the writer, the greater
+the risk of illusion from this source as well as from that of
+dream-fancies. It is highly probable, indeed, that in such full and
+explicit records of very early life as those given by Rousseau, by
+Goethe, or by De Quincey, some part of the quasi-narrative is based on
+mental images which come floating down the stream of time, not from the
+substantial world of the writer's personal experience, but from the airy
+region of dream-land or of waking fancy.</p>
+
+<p>It is to be added that even when the quasi-recollection does answer to a
+real event of childish history, it may still be an illusion. The fact
+that others, in narrating events to us, are able to awaken imaginations
+that afterwards appear as past realities, suggests that much of our
+supposed early recollection owes its existence to what our parents and
+friends have from time to time told us respecting the first stages of
+our history.<a name="FNanchor_131_131" id="FNanchor_131_131"></a><a href="#Footnote_131_131" class="fnanchor">[131]</a> We see, then, how much uncertainty attaches to all
+autobiographical description of very early life.</p>
+
+<p>Modern science suggests another possible source of these distinct
+spectra of memory. May it not happen that, by the law of hereditary
+transmission, which is now being applied to mental as well as bodily
+phenomena, ancestral experiences will now and then reflect<span class='pagenum'><a name="Page_281" id="Page_281">[Pg 281]</a></span> themselves
+in our mental life, and so give rise to apparently personal
+recollections? No one can say that this is not so. When the infant first
+steadies his eyes on a human face, it may, for aught we know, experience
+a feeling akin to that described above, when through a survival of
+dream-fancy we take some new scene to be already familiar. At the age
+when new emotions rapidly develop themselves, when our hearts are full
+of wild romantic aspirations, do there not seem to blend with the eager
+passion of the time deep resonances of a vast and mysterious past, and
+may not this feeling be a sort of reminiscence of prenatal, that is,
+ancestral experience?</p>
+
+<p>This idea is certainly a fascinating one, worthy to be a new scientific
+support for the beautiful thought of Plato and of Wordsworth. But in our
+present state of knowledge, any reasoning on this supposition would
+probably appear too fanciful. Some day we may find out how much
+ancestral experience is capable of bequeathing in this way, whether
+simply shadowy, undefinable mental tendencies, or something like
+definite concrete ideas. If, for example, it were found that a child
+that was descended from a line of seafaring ancestors, and that had
+never itself seen or heard of the "dark-gleaming sea," manifested a
+feeling of recognition when first beholding it, we might be pretty sure
+that such a thing as recollection of prenatal events does take place.
+But till we have such facts, it seems better to refer the "shadowy
+recollections" to sources which fall within the individual's own
+experience.</p>
+
+<p>We may now pass to those hallucinations of memory which are analogous to
+the <i>centrally</i> excited<span class='pagenum'><a name="Page_282" id="Page_282">[Pg 282]</a></span> hallucinations of sense-perception. As I have
+observed, these are necessarily vague and imperfectly developed.</p>
+
+<p>I have already had occasion to touch on the fact of the vast amount of
+our forgotten experience. And I observed that forgetfulness was a common
+negative condition of mnemonic illusion. I have now to complete this
+statement by the observation that total forgetfulness of any period or
+stage of our past experience necessarily tends to a vague kind of
+hallucination. In looking back on the past, we see no absolute gaps in
+the continuity of our conscious life; our image of this past is
+essentially one of an unbroken series of conscious experiences. But if
+through forgetfulness a part of the series is effaced from memory, how,
+it may be asked, is it possible to construct this perfectly continuous
+line? The answer is that we fill up such lacun&aelig; vaguely by help of some
+very imperfectly imagined common type of conscious experience. Just as
+the eye sees no gap in its field of vision corresponding to the "blind
+spot" of the retina, but carries its impression over this area, so
+memory sees no lacuna in the past, but carries its image of conscious
+life over each of the forgotten spaces.</p>
+
+<p>Sometimes this process of filling in gaps in the past becomes more
+complete. Thus, for example, in recalling a particular night a week or
+so ago, I instinctively represent it to myself as so many hours of lying
+in bed with the waking sensations appropriate to the circumstances, as
+those of bodily warmth and rest, and of the surrounding silence and
+darkness.</p>
+
+<p>It is apparent that I cannot conceive myself apart<span class='pagenum'><a name="Page_283" id="Page_283">[Pg 283]</a></span> from some mode of
+conscious experience. In thinking of myself in any part of the past or
+future in which there is actually no consciousness, or of which the
+conscious content is quite unknown to me, I necessarily imagine myself
+as consciously experiencing something. If I picture myself under any
+definitely conceived circumstances, I irresistibly import into my mental
+image the feelings appropriate to these surroundings. In this way,
+people tend to imagine themselves after death as lying in the grave,
+feeling its darkness and its chilliness. If the circumstances of the
+time are not distinctly represented, the conception of the conscious
+experience which constitutes that piece of the ego is necessarily vague,
+and seems generally to resolve itself into a representation of ourselves
+as dimly <i>self-conscious</i>. What this consciousness of self consists of
+is a point that will be taken up presently.</p>
+
+
+<p class='center'><i>Illusions with respect to Personal Identity.</i></p>
+
+<p>It would seem to follow from these errors in imaginatively filling up
+our past life, that our consciousness of personal identity is by no
+means the simple and exact process which it is commonly supposed to be.
+I have already remarked that the very fact of there being so large a
+region of the irrevocable in our past experience proves our
+consciousness of personal continuity to be largely a matter of
+inference, or of imaginative conjecture, and not simply of immediate
+recollection. Indeed, it may be said that our power of ignoring whole
+regions of the past and of leaping complacently over huge gaps in our
+memory and linking on conscious experience with conscious ex<span class='pagenum'><a name="Page_284" id="Page_284">[Pg 284]</a></span>perience,
+involves an illusory sense of continuity, and so far of personal
+identity. Thus, our ordinary image of our past life, if only by omitting
+the very large fraction passed in sleep, in at least an approximately
+unconscious state, clearly contains an ingredient of illusion.<a name="FNanchor_132_132" id="FNanchor_132_132"></a><a href="#Footnote_132_132" class="fnanchor">[132]</a></p>
+
+<p>It is to be added that the numerous falsifications of our past history,
+which our retrospective imagination is capable of perpetrating, make our
+representation of ourselves at different moments and in different stages
+of our past history to a considerable extent illusory. Thus, though to
+mistake a past dream-experience for a waking one may not be to lose or
+confuse the sense of identity, since our dreams are, after all, a part
+of our experience, yet to imagine that we have ourselves seen what we
+have only heard from another or read is clearly to confuse the
+boundaries of our identity. And with respect to longer sections of our
+history, it is plain that when we wrongly assimilate our remote to our
+present self, and clothe our childish nature with the feelings and the
+ideas of our adult life, we identify ourselves overmuch. In this way,
+through the corruption of our memory, a kind of sham self gets mixed up
+with the real self, so that we cannot, strictly speaking, be sure that
+when we project a mnemonic image into the remote past we are not really
+running away from our true personality.<span class='pagenum'><a name="Page_285" id="Page_285">[Pg 285]</a></span></p>
+
+<p>So far I have been touching only on slight errors in the recognition of
+that identical self which is represented as persisting through all the
+fluctuations of conscious life. Other and grosser illusions connected
+with personal identity are also found to be closely related to defects
+or disturbances of the ordinary mnemonic process, and so can be best
+treated here. In order to understand these, we must inquire a little
+into the nature of our idea and consciousness of a persistent self.
+Here, again, I would remind the reader that I am treating the point only
+so far as it can be treated scientifically or empirically, that is to
+say, by examining what concrete facts or data of experience are taken up
+into the idea of self. I do not wish to foreclose the philosophic
+question whether anything more than this empirical content is involved
+in the conception.</p>
+
+<p>My idea of myself as persisting appears to be built up of certain
+similarities in the succession of my experiences. Thus, my permanent
+self consists, on the bodily side, of a continually renewable perception
+of my own organism, which perception is mainly visual and tactual, and
+which remains pretty constant within certain limits of time. With this
+objective similarity is closely conjoined a subjective similarity. Thus,
+the same sensibilities continue to characterize the various parts of my
+organism. Similarly, there are the higher intellectual, emotional, and
+moral peculiarities and dispositions. My idea of my persistent self is
+essentially a collective image representing a relatively unchanging
+material object, endowed with unchanging sensibilities and forming a
+kind of support for permanent higher mental attributes.<span class='pagenum'><a name="Page_286" id="Page_286">[Pg 286]</a></span></p>
+
+<p>The construction of this idea of an enduring unchanging ego is rendered
+very much easier by the fact that certain concrete feelings are
+approximately constant elements in our mental life. Among these must be
+ranked first that dimly discriminated mass of organic sensation which in
+average states of health is fairly constant, and which stands in sharp
+contrast to the fluctuating external sensations. These feelings enter
+into and profoundly colour each person's mental image of himself. In
+addition to this, there are the frequently recurring higher feelings,
+the dominant passions and ideas which approximate more or less closely
+to constant factors of our conscious experience.</p>
+
+<p>This total image of the ego becomes defined and rendered precise by a
+number of distinctions, as that between my own body or that particular
+material object with which are intimately united all my feelings, and
+other material objects in general; then between my organism and other
+human organisms, with which I learn to connect certain feelings
+answering to my own, but only faintly represented instead of actually
+realized feelings. To these prime distinctions are added others, hardly
+less fundamental, as those between my individual bodily appearance and
+that of other living bodies, between my personal and characteristic
+modes of feeling and thinking and those of others, and so on.</p>
+
+<p>Our sense of personal identity may be said to be rooted in that special
+side of the mnemonic process which consists in the linking of all
+sequent events together by means of a thread of common consciousness. It
+is closely connected with that smooth,<span class='pagenum'><a name="Page_287" id="Page_287">[Pg 287]</a></span> gliding movement of imagination
+which appears to involve some more or less distinct consciousness of the
+uniting thread of similarity. And so long as this movement is possible,
+so long, that is to say, as retrospective imagination detects the common
+element, which we may specifically call the recurring consciousness of
+self, so long is there the undisturbed assurance of personal identity.
+Nay, more, even when such a recognition might seem to be difficult, if
+not impossible, as in linking together the very unlike selves, viewed
+both on their objective and subjective sides, of childhood, youth, and
+mature life, the mind manages, as we have seen, to feign to itself a
+sufficient amount of such similarity.</p>
+
+<p>But this process of linking stage to stage, of discerning the common or
+the recurring amid the changing and the evanescent, has its limits.
+Every great and sudden change in our experience tends, momentarily at
+least, to hinder the smooth reflux of imagination. It makes too sharp a
+break in our conscious life, so that imagination is incapable of
+spanning the gap and realizing the then and the now as parts of a
+connected continuous tissue.<a name="FNanchor_133_133" id="FNanchor_133_133"></a><a href="#Footnote_133_133" class="fnanchor">[133]</a></p>
+
+<p>These changes may be either objective or subjective. Any sudden
+alteration of our bodily appearance sensibly impedes the movement of
+imagination. A patient after a fever, when he first looks in the glass,<span class='pagenum'><a name="Page_288" id="Page_288">[Pg 288]</a></span>
+exclaims, "I don't know myself." More commonly the bodily changes which
+affect the consciousness of an enduring self are such as involve
+considerable alterations of c&oelig;n&aelig;sthesis, or the mass of stable
+organic sensation. Thus, the loss of a limb, by cutting off a portion of
+the old sensations through which the organism may be said to be
+immediately felt, and by introducing new and unfamiliar feelings, will
+distinctly give a shock to our consciousness of self.</p>
+
+<p>Purely subjective changes, too, or, to speak correctly, such as are
+known subjectively only, will suffice to disturb the sense of personal
+unity. Any great moral shock, involving something like a revolution in
+our recurring emotional experience, seems at the moment to rupture the
+bond of identity. And even some time after, as I have already remarked,
+such cataclysms in our mental geology lead to the imaginative thrusting
+of the old personality away from the new one under the form of a "dead
+self."<a name="FNanchor_134_134" id="FNanchor_134_134"></a><a href="#Footnote_134_134" class="fnanchor">[134]</a></p>
+
+<p>We see, then, that the failure of our ordinary assurance of personal
+identity is due to the recognition of difference without similarity. It
+arises from an act of memory&mdash;for the mind must still be able to recall
+the past, dimly at least&mdash;but from a memory which misses its habitual
+support in a recognized<span class='pagenum'><a name="Page_289" id="Page_289">[Pg 289]</a></span> element of constancy. If there is no memory,
+that is to say, if the past is a complete blank, the mind simply feels a
+rupture of identity without any transformation of self. This is our
+condition on awaking from a perfectly forgotten period of sleep, or from
+a perfectly unconscious state (if such is possible) when induced by
+an&aelig;sthetics. Such gaps are, as we have seen, easily filled up, and the
+sense of identity restored by a kind of retrospective "skipping." On the
+other hand, the confusion which arises from too great and violent a
+transformation of our <i>remembered</i> experiences is much less easily
+corrected. As long as the recollection of the old feelings remains, and
+with this the sense of violent contrast between the old and the new
+ones, so long will the illusion of two sundered selves tend to recur.</p>
+
+<p>The full development of this process of imaginative fission or cleavage
+of self is to be met with in mental disease. The beginnings of such
+disease, accompanied as they commonly are with disturbances of bodily
+sensations and the recurring emotions, illustrate in a very interesting
+way the dependence of the recognition of self on a certain degree of
+uniformity in the contents of consciousness. The patient, when first
+aware of these changes, is perplexed, and often regards the new feelings
+as making up another self, a foreign <i>Tu</i>, as distinguished from the
+familiar <i>Ego</i>. And sometimes he expresses the relation between the old
+and the new self in fantastic ways, as when he imagines the former to be
+under the power of some foreign personality.</p>
+
+<p>When the change is complete, the patient is apt to<span class='pagenum'><a name="Page_290" id="Page_290">[Pg 290]</a></span> think of his former
+self as detached from his present, and of his previous life as a kind of
+unreal dream; and this fading away of the past into shadowy unreal forms
+has, as its result, a curious aberration in the sense of time. Thus, it
+is said that a patient, after being in an asylum only one day, will
+declare that he has been there a year, five years, and even ten
+years.<a name="FNanchor_135_135" id="FNanchor_135_135"></a><a href="#Footnote_135_135" class="fnanchor">[135]</a> This confusion as to self naturally becomes the
+starting-point of illusions of perception; the transformation of self
+seeming to require as its logical correlative (for there is a crude
+logic even in mental disease) a transformation of the environment. When
+the disease is fully developed under the particular form of monomania,
+the recollection of the former normal self commonly disappears
+altogether, or fades away into a dim image of some perfectly separate
+personality. A new ego is now fully substituted for the old. In other
+and more violent forms of disease (dementia) the power of connecting the
+past and present may disappear altogether, and nothing but the <i>disjecta
+membra</i> of an ego remain.</p>
+
+<hr style='width: 45%;' />
+
+<p>Enough has, perhaps, been said to show how much of uncertainty and of
+self-deception enters into the processes of memory. This much-esteemed
+faculty, valuable and indispensable though it certainly is, can clearly
+lay no claim to that absolute infallibility which is sometimes said to
+belong to it. Our individual recollection,<span class='pagenum'><a name="Page_291" id="Page_291">[Pg 291]</a></span> left to itself, is liable to
+a number of illusions even with regard to fairly recent events, and in
+the case of remote ones it may be said to err habitually and uniformly
+in a greater or less degree. To speak plainly, we can never be certain
+on the ground of our personal recollection alone that a distant event
+happened exactly in the way and at the time that we suppose. Nor does
+there seem to be any simple way by mere reflection on the contents of
+our memory of distinguishing what kinds of recollection are likely to be
+illusory.</p>
+
+<p>How, then, it may be asked, can we ever be certain that we are
+faithfully recalling the actual events of the past? Given a fairly good,
+that is, a cultivated memory, it may be said that in the case of very
+recent events a man may feel certain that, when the conditions of
+careful attention at the time to what really happened were present, a
+distinct recollection is substantially correct. Also it is obvious that
+with respect to all repeated experiences our memories afford practically
+safe guides. When memory becomes the basis of some item of generalized
+knowledge, as, for example, of the truth that the pain of indigestion
+has followed a too copious indulgence in rich food, there is little room
+for an error of memory properly so called. On the other hand, when an
+event is not repeated in our experience, but forms a unique link in our
+personal history, the chances of error increase with the distance of the
+event; and here the best of us will do well to have resort to a process
+of verification or, if necessary, of correction.</p>
+
+<p>In order thus to verify the utterances of memory, we must look beyond
+our own internal mental states<span class='pagenum'><a name="Page_292" id="Page_292">[Pg 292]</a></span> to some external facts. Thus, the
+recollections of our early life may often be tested by letters written
+by ourselves or our friends at the time, by diaries, and so on. When
+there is no unerring objective record to be found, we may have recourse
+to the less satisfactory method of comparing our recollections with
+those of others. By so doing we may reach a rough average recollection
+which shall at least be free from any individual error corresponding to
+that of personal equation in perception. But even thus we cannot be sure
+of eliminating all error, since there may be a cause of illusion acting
+on all our minds alike, as, for example, the extraordinary nature of the
+occurrence, which would pretty certainly lead to a common exaggeration
+of its magnitude, etc., and since, moreover, this process of comparing
+recollections affords an opportunity for that reading back a present
+preconception into the past to which reference has already been made.</p>
+
+<p>The result of our inquiry is less alarming than it looks at first sight.
+Knowledge is valuable for action, and error is chiefly hurtful in so far
+as it misdirects conduct. Now, in a general way, we do not need to act
+upon a recollection of single remote events; our conduct is sufficiently
+shaped by an accurate recollection of single recent events, together
+with those bundles of recollections of recurring events and sequences of
+events which constitute our knowledge of ourselves and our common
+knowledge of the world about us. Nature has done commendably well in
+endowing us with the means of cultivating our memories up to this point,
+and we ought not to blame her for not giving us powers which would only
+very rarely prove of any appreciable practical service to us.<span class='pagenum'><a name="Page_293" id="Page_293">[Pg 293]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>NOTE.</h2>
+
+<h4>MOMENTARY ILLUSIONS OF SELF-CONSCIOUSNESS.</h4>
+
+
+<p>The account of the apparent ruptures in our personal identity given in
+this chapter may help us to understand the strange tendency to confuse
+self with other objects which occasionally appears in waking
+consciousness and in dreams. These errors may be said generally to be
+due to the breaking up of the composite image of self into its
+fragments, and the regarding of certain of these only. Thus, the
+momentary occurrence of partial illusion in intense sympathy with
+others, including that imaginative projection of self into inanimate
+objects, to which reference has already been made, may be said to depend
+on exclusive attention to the subjective aspect of self, to the total
+disregard of the objective aspect. In other words, when we thus
+momentarily "lose ourselves," or merge our own existence in that of
+another object, we clearly let drop out of sight the visual
+representation of our own individual organism. On the other hand, when
+in dreams we double our personality, or represent to ourselves an
+external self which becomes the object of visual perception, it is
+probably because we isolate in imagination the objective aspect of our
+personality from the other and subjective aspect. It is not at all
+unlikely that the several confusions of self touched on in this chapter
+have had something to do with the genesis of the various historical
+theories of a transformed existence, as, for example, the celebrated
+doctrine of metempsychosis.<span class='pagenum'><a name="Page_294" id="Page_294">[Pg 294]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER XI.</h2>
+
+<h4>ILLUSIONS OF BELIEF.</h4>
+
+
+<p>Our knowledge is commonly said to consist of two large
+varieties&mdash;Presentative and Representative. Representative knowledge,
+again, falls into two chief divisions. The first of these is Memory,
+which, though not primary or original, like presentative knowledge, is
+still regarded as directly or intuitively certain. The second division
+consists of all other representative knowledge besides memory,
+including, among other varieties, our anticipations of the future, our
+knowledge of others' past experience, and our general knowledge about
+things. There is no one term which exactly hits off this large sphere of
+cognition: I propose to call it Belief. I am aware that this is by no
+means a perfect word for my purpose, since, on the one hand, it suggests
+that every form of this knowledge must be less certain than presentative
+or mnemonic knowledge, which cannot be assumed; and since, on the other
+hand, the word is so useful a one in psychology, for the purpose of
+marking off the subjective fact of assurance in all kinds of cognition.
+Nevertheless, I know not what better one I could select in order to<span class='pagenum'><a name="Page_295" id="Page_295">[Pg 295]</a></span>
+make my classification answer as closely as a scientific treatment will
+allow to the deeply fixed distinctions of popular psychology.</p>
+
+<p>It might at first seem as if perception, introspection, and memory must
+exhaust all that is meant by immediate, or self-evident, knowledge, and
+as if what I have here called belief must be uniformly mediate,
+derivate, or inferred knowledge. The apprehension of something now
+present to the mind, externally or internally, and the reapprehension
+through the process of memory of what was once so apprehended, might
+appear to be the whole of what can by any stretch of language be called
+direct cognition of things. This at least would seem to follow from the
+empirical theory of knowledge, which regards perception and memory as
+the ground or logical source of all other forms of knowledge.</p>
+
+<p>And even if we suppose, with some philosophers, that there are certain
+innate principles of knowledge, it seems now to be generally allowed
+that these, apart from the particular facts of experience, are merely
+abstractions; and that they only develop into complete knowledge when
+they receive some empirical content, which must be supplied either by
+present perception or by memory. So that in this case, too, all definite
+concrete knowledge would seem to be either presentative cognition,
+memory, or, lastly, some mode of inference from these.</p>
+
+<p>A little inquiry into the mental operations which I here include under
+the name belief will show, however, that they are by no means uniformly
+process of inference. To take the simplest form of such know<span class='pagenum'><a name="Page_296" id="Page_296">[Pg 296]</a></span>ledge,
+anticipation of some personal experience: this may arise quite apart
+from recollection, as a spontaneous projection of a mental image into
+the future. A person may feel "intuitively certain" that something is
+going to happen to him which does not resemble anything in his past
+experience. Not only so; even when the expectation corresponds to a bit
+of past experience, this source of the expectation may, under certain
+circumstances, be altogether lost to view, and the belief assume a
+secondarily automatic or intuitive character. Thus, a man may have first
+entertained a belief in the success of some undertaking as the result of
+a rough process of inference, but afterwards go on trusting when the
+grounds for his confidence are wholly lost sight of.</p>
+
+<p>This much may suffice for the present to show that belief sometimes
+approximates to immediate, or self-evident, conviction. How far this is
+the case will come out in the course of our inquiry into its different
+forms. This being so, it will be needful to include in our present study
+the errors connected with the process of belief in so far as they
+simulate the immediate instantaneous form of illusion.</p>
+
+<p>What I have here called belief may be roughly distinguished into simple
+and compound belief. By a simple belief I mean one which has to do with
+a single event or fact. It includes simple modes of expectation, as well
+as beliefs in single past facts not guaranteed by memory. A compound
+belief, on the other hand, has reference to a number of events or facts.
+Thus, our belief in the continued existence of a particular object, as
+well as our convictions respecting groups or classes<span class='pagenum'><a name="Page_297" id="Page_297">[Pg 297]</a></span> of events, must be
+regarded as compound, since they can be shown to include a number of
+simple beliefs.</p>
+
+
+<p class='center'>A. <i>Simple Illusory Belief: Expectation.</i></p>
+
+<p>It will be well to begin our inquiry by examining the errors connected
+with simple expectations, so far as these come under our definition of
+illusion. And here, following our usual practice, we may set out with a
+very brief account of the nature of the intellectual process in its
+correct form. For this purpose we shall do well to take a complete or
+definite anticipation of an event as our type.<a name="FNanchor_136_136" id="FNanchor_136_136"></a><a href="#Footnote_136_136" class="fnanchor">[136]</a></p>
+
+<p>The ability of the mind to move forward, forecasting an order of events
+in time, is clearly very similar to its power of recalling events. Each
+depends on the capability of imagination to represent a sequence of
+events or experiences. The difference between the two processes is that
+in anticipation the imagination setting out from the present traces the
+succession of experiences in their actual order, and not in the reverse
+order. It would thus appear to be a more natural and easy process than
+recollection, and observation bears out this conclusion. Any object
+present to perception which is associated with antecedents and
+consequents with the same degree of cohesion, calls up its consequents
+rather than its antecedents. The spectacle of the rising of the sun
+carries the mind much more forcibly forwards to the advancing morn<span class='pagenum'><a name="Page_298" id="Page_298">[Pg 298]</a></span>ing
+than backwards to the receding night. And there is good reason to
+suppose that in the order of mental development the power of distinctly
+expecting an event precedes that of distinctly recollecting one. Thus,
+in the case of the infant mind, as of the animal intelligence, the
+presence of signs of coming events, as the preparation of food, seems to
+excite distinct and vivid expectation.<a name="FNanchor_137_137" id="FNanchor_137_137"></a><a href="#Footnote_137_137" class="fnanchor">[137]</a></p>
+
+<p>As a mode of assurance, expectation is clearly marked off from memory,
+and is not explainable by means of this. It is a fundamentally distinct
+kind of conviction. So far as we are capable of analyzing it, we may say
+that its peculiarity is its essentially active character. To expect a
+thing is to have stirred the active impulses, including the powers of
+attention; it is to be on the alert for it, to have the attention
+already focussed for it, and to begin to rehearse the actions which the
+actual happening of the event&mdash;for example, the approach of a welcome
+object&mdash;would excite. It thus stands in marked contrast to memory, which
+is a passive attitude of mind, becoming active only when it gives rise
+to the expectation of a recurrence of the event.<a name="FNanchor_138_138" id="FNanchor_138_138"></a><a href="#Footnote_138_138" class="fnanchor">[138]</a></p>
+
+<p>And now let us pass to the question whether expectation ever takes the
+form of immediate knowledge.<span class='pagenum'><a name="Page_299" id="Page_299">[Pg 299]</a></span> It may, perhaps, be objected that the
+anticipation of something future cannot be knowledge at all in the sense
+in which the perception of something present or the recollection of
+something past is knowledge. But this objection, when examined closely,
+appears to be frivolous. Because the future fact has not yet come into
+the sphere of actual existence, it is none the less the object of a
+perfect assurance.<a name="FNanchor_139_139" id="FNanchor_139_139"></a><a href="#Footnote_139_139" class="fnanchor">[139]</a></p>
+
+<p>But, even if it is conceded that expectation is knowledge, the objection
+may still be urged that it cannot be immediate, since it is the very
+nature of expectation to ground itself on memory. I have already hinted
+that this is not the case, and I shall now try to show that what is
+called expectation covers much that is indistinguishable from immediate
+intuitive certainty, and consequently offers room for an illusory form
+of error.</p>
+
+<p>Let us set out with the simplest kind of expectation, the anticipation
+of something about to happen within the region of our personal
+experience, and similar to what has happened before. And let the coming
+of the event be first of all suggested by some present external fact or
+sign. Suppose, for example, that the sky is heavy, the air sultry, and
+that I have a bad headache; I confidently anticipate a thunderstorm. It
+would commonly be said that such an expectation is a kind of inference
+from the past. I remember that these appearances have been followed by a
+thunderstorm very often, and I infer that they will in this new case be
+so followed.<span class='pagenum'><a name="Page_300" id="Page_300">[Pg 300]</a></span></p>
+
+<p>To this, however, it may be replied that in most cases there is no
+conscious going back to the past at all. As I have already remarked,
+anticipation is pretty certainly in advance of memory in early life. And
+even after the habit of passing from the past to the future, from memory
+to expectation, has been formed, the number of the past repetitions of
+experience would prevent the mind's clearly reverting to them. And,
+further, the very force of habit would tend to make the transition from
+memory to expectation more and more rapid, automatic, and unconscious.
+Thus it comes about that all distinctly suggested approaching events
+seem to be expected by a kind of immediate act of belief. The present
+signs call up the representation of the coming event with all the force
+of a direct intuition. At least, it may be said that if a process of
+inference, it is one which has the minimum degree of consciousness.</p>
+
+<p>It might still be urged that the mind passes from the <i>present</i> facts as
+signs, and so still performs a kind of reasoning process. This is, no
+doubt, true, and differentiates expectation from perception, in which
+there is no conscious transition from the presented to the represented.
+Still I take it that this is only a process of reasoning in so far as
+the sign is consciously generalized, and this is certainly not true of
+early expectations, or even of any expectations in a wholly uncultivated
+mind.</p>
+
+<p>For these reasons I think that any errors involved in such an
+anticipation may, without much forcing, be brought under our definition
+of illusion. When due altogether to the immediate force of suggestion in
+a present object or event, and not involving any con<span class='pagenum'><a name="Page_301" id="Page_301">[Pg 301]</a></span>scious transition
+from past to future, or from general truth to particular instance, these
+errors appear to me to have more of the character of illusions than of
+that of fallacies.</p>
+
+<p>Much the same thing may be said about the vivid anticipations of a
+familiar kind of experience called up by a clear and consecutive verbal
+suggestion. When a man, even with an apparent air of playfulness, tells
+me that something is going to happen, and gives a consistent consecutive
+account of this, I have an anticipation which is not consciously
+grounded on any past experience of the value of human testimony in
+general, or of this person's testimony in particular, but which is
+instantaneous and quasi-immediate. Consequently, any error connected
+with the mental act approximates to an illusion.</p>
+
+<p>So far I have supposed that the anticipated event is a recurring one,
+that is to say, a kind of experience which has already become familiar
+to us. This, however, holds good only of a very few of our experiences.
+Our life changes as it progresses, both outwardly and inwardly. Many of
+our anticipations, when first formed, involve much more than a
+reproduction of a past experience, namely, a complex act of constructive
+imagination. Our representations of these untried experiences, as, for
+example, those connected with a new set of circumstances, a new social
+condition, a new mode of occupation, and so on, are clearly at the first
+far from simple processes of inference from the past. They are put
+together by the aid of many fragmentary images, restored by distinct
+threads of association, yet by a process so rapid as to appear like an
+intuition. Indeed,<span class='pagenum'><a name="Page_302" id="Page_302">[Pg 302]</a></span> the anticipation of such new experiences more often
+resembles an instantaneous imaginative intuition than a process of
+conscious transition from old experiences. In the case of these
+expectations, then, there would clearly seem to be room for illusion
+from the first.</p>
+
+<p>But even supposing that the errors connected with the first formation of
+an expectation cannot strictly be called illusory, we may see that such
+simple expectation will, in certain cases, tend to grow into something
+quite indistinguishable from illusion. I refer to expectations of
+<i>remote</i> events which allow of frequent renewal. Even supposing the
+expectation to have originated from some rational source, as from a
+conscious inference from past experience, or from the acceptance of
+somebody's statement, the very habit of cherishing the anticipation
+tends to invest it with an automatic self-sufficient character. To all
+intents and purposes the prevision becomes intuitive, by which I mean
+that the mind is at the time immediately certain that something is going
+to happen, without needing to fall back on memory or reflection. This
+being so, whenever the initial process of inference or quasi-inference
+happens to have been bad, an illusory expectation may arise. In other
+words, the force of repetition and habit tends to harden what may, in
+its initial form, have resembled a kind of fallacy into an illusion.</p>
+
+<p>And now let us proceed further. When a permanent expectation is thus
+formed, there arises the possibility of processes which favour illusion
+precisely analogous to those which we have studied in the case of
+memory.</p>
+
+<p>In the first place, the habit of imagining a future event is attended
+with a considerable amount of<span class='pagenum'><a name="Page_303" id="Page_303">[Pg 303]</a></span> illusion as to time or remoteness. After
+what has been said respecting the conditions of such error in the case
+of memory, a very few words will suffice here.</p>
+
+<p>It is clear, then, in the first place, that the mind will tend to
+shorten any period of future time, and so to antedate, so to speak, a
+given event, in so far as the imagination is able clearly and easily to
+run over its probable experiences. From this it follows that repeated
+forecastings of series of events, by facilitating the imaginative
+process, tend to beget an illusory appearance of contraction in the time
+anticipated. Moreover, since in anticipation so much of each division of
+the future time-line is unknown, it is obviously easy for the expectant
+imagination to skip over long intervals, and so to bring together widely
+remote events.</p>
+
+<p>In addition to this general error, there are more special errors. As in
+the case of recollection, vividness of mental image suggests
+propinquity; and accordingly, all vivid anticipations, to whatever cause
+the vividness may be owing, whether to powerful suggestion on the part
+of external objects, to verbal suggestion, or to spontaneous imagination
+and feeling, are apt to represent their objects as too near.</p>
+
+<p>It follows that an event intensely longed for, in so far as the
+imagination is busy in representing it, will seem to approach the
+present. At the same time, as we have seen, an event much longed for
+commonly appears to be a great while coming, the explanation being that
+there is a continually renewed contradiction between anticipation and
+perception. The self-adjust<span class='pagenum'><a name="Page_304" id="Page_304">[Pg 304]</a></span>ment of the mind in the attitude of
+expectant attention proves again and again to be vain and futile, and it
+is this fact which brings home to it the slowness of the sequences of
+perceived fact, as compared with the rapidity of the sequences of
+imagination.</p>
+
+<p>When speaking of the retrospective estimate of time, I observed that the
+apparent distance of an event depends on our representation of the
+intervening time-segment. And the same remark applies to the prospective
+estimate. Thus, an occurrence which we expect to happen next week will
+seem specially near if we know little or nothing of the contents of the
+intervening space, for in this case the imagination does not project the
+experience behind a number of other distinctly represented events.</p>
+
+<p>Finally, it is to be remarked that the prospective appreciation of any
+duration will tend to err relatively by way of excess, where the time is
+exceptionally filled out with clearly expected and deeply interesting
+experiences. To the imagination of the child, a holiday, filled with new
+experiences, appears to be boundless.</p>
+
+<p>Thus far I have assumed that the date of the future event is a matter
+which might be known. It is, however, obvious, from the very nature of
+knowledge with respect to the future, that we may sometimes be certain
+of a thing happening to us without knowing with any degree of
+definiteness when it will happen. In the case of these temporally
+undefined expectations, the law already expounded holds good that all
+vividness of representation tends to lend the things represented an
+appearance of approaching events. On the other hand, there are some
+events, such as our own death,<span class='pagenum'><a name="Page_305" id="Page_305">[Pg 305]</a></span> which our instinctive feelings tend to
+banish to a region so remote as hardly to be realized at all.</p>
+
+<p>So much with respect to errors in the localizing of future events.</p>
+
+<p>In the second place, a habit of imagining a future event or group of
+events will give play to those forces which tend to transform a mental
+image. In other words, the habitual indulgence of a certain anticipation
+tends to an illusory view, not only of the "when?" but also of the
+"how?" of the future event. These transformations, due to subtle
+processes of emotion and intellect, and reflecting the present habits of
+these, exactly resemble those by which a remembered event becomes
+gradually transformed. Thus, we carry on our present habits of thought
+and feeling into the remote future, foolishly imagining that at a
+distant period of life, or in greatly altered circumstances, we shall
+desire and aim at the same things as now in our existing circumstances.
+In close connection with this forward projection of our present selves,
+there betrays itself a tendency to look on future events as answering to
+our present desires and aspirations. In this way, we are wont to soften,
+beautify, and idealize the future, marking it off from the hard
+matter-of-fact present.</p>
+
+<p>The less like the future experience to our past experience, or the more
+remote the time anticipated, the greater the scope for such imaginative
+transformation. And from this stage of fanciful transformation of a
+future reality to the complete imaginative creation of such a reality,
+the step is but a small one. Here we reach the full development of
+illusory expectation,<span class='pagenum'><a name="Page_306" id="Page_306">[Pg 306]</a></span> that which corresponds to hallucination in the
+region of sense-perception.</p>
+
+<p>In order to understand these extreme forms of illusory expectation, it
+will be necessary to say something more about the relation of
+imagination to anticipation in general. There are, I conceive, good
+reasons for saying that any kind of vivid imagination tends to pass into
+a semblance of an expectation of a coming personal experience, or an
+event that is about to happen within the sphere of our own observation.
+It has long been recognized by writers, among whom I may mention Dugald
+Stewart, that to distinctly imagine an event or object is to feel for
+the moment a degree of belief in the corresponding reality. Now, I have
+already said that expectation is probably a more natural and an earlier
+developed state of mind than memory. And so it seems probable that any
+mental image which happens to take hold on the mind, if not recognized
+as one of memory, or as corresponding to a fact in somebody else's
+experience, naturally assumes the form of an expectation of a personal
+experience. The force of the expectation will vary in general as the
+vividness and persistence of the mental image. Moreover, it follows,
+from what has been said, that this force of imagination will determine
+what little time-character we ever give to these wholly ungrounded
+illusions.</p>
+
+<p>We see, then, that any process of spontaneous imagination will tend to
+beget some degree of illusory expectation. And among the agencies by
+which such ungrounded imagination arises, the promptings of feeling play
+the most conspicuous part. A present emotional excitement may give to an
+imaginative anticipation,<span class='pagenum'><a name="Page_307" id="Page_307">[Pg 307]</a></span> such as that of the prophetic enthusiast, a
+reality which approximates to that of an actually perceived object. And
+even where this force of excitement is wanting, a gentle impulse of
+feeling may suffice to beget an assurance of a distant reality. The
+unknown recesses of the remote future offer, indeed, the field in which
+the illusory impulses of our emotional nature have their richest
+harvest.</p>
+
+<p>
+<span style="margin-left: 1em;">"Thus, from afar, each dim discover'd scene</span><br />
+<span style="margin-left: 1.5em;">More pleasing seems than all the past hath been;</span><br />
+<span style="margin-left: 1.5em;">And every form, that Fancy can repair</span><br />
+<span style="margin-left: 1.5em;">From dark oblivion, glows divinely there."</span><br />
+</p>
+
+<p>The recurring emotions, the ruling aspirations, find objects for
+themselves in this veiled region. Feelings too shy to burst forth in
+unseemly anticipation of the immediate future, modestly satisfy
+themselves with this remote prospect of satisfaction. And thus, there
+arises the half-touching, half-amusing spectacle of men and women
+continually renewing illusory hopes, and continually pushing the date of
+their realization further on as time progresses and brings no actual
+fruition.</p>
+
+<p>So far I have spoken of such expectations as refer to future personal
+experience only. Growing individual experience and the enlargement of
+this by the addition of social experience enable us to frame a number of
+other beliefs more or less similar to the simple expectations just dealt
+with. Thus, for example, I can forecast with confidence events which
+will occur in the lives of others, and which I shall not even witness;
+or again, I may even succeed in dimly descrying events, such as
+political changes or scientific discoveries, which will happen after my
+personal experience is at an end.<span class='pagenum'><a name="Page_308" id="Page_308">[Pg 308]</a></span> Once more, I can believe in something
+going on now at some distant and even inaccessible point of the
+universe, and this appears to involve a conditional expectation, and to
+mean that I am certain that I or anybody else would see the phenomenon,
+if we could at this moment be transported to the spot.</p>
+
+<p>All such previsions are supposed to be formed by a process of inference
+from personal experience, including the trustworthiness of testimony.
+Even allowing, however, that this was so in the first stages of the
+belief, it is plain that, by dint of frequent renewal, the expectation
+would soon cease to be a process of inference, and acquire an apparently
+self-evident character. This being so, if the expectation is not
+adequately grounded to start with, it is very likely to develop into an
+illusion. And it is to be added that these permanent anticipations may
+have their origin much more in our own wishes or emotional promptings
+than in fact and experience. The mind undisciplined by scientific
+training is wont to entertain numerous beliefs of this sort respecting
+what is now going on in unvisited parts of the world, or what will
+happen hereafter in the distant future. The remote, and therefore
+obscure, in space and in time has always been the favourite region for
+the projection of pleasant fancies.</p>
+
+<p>Once more, besides these oblique kinds of expectation, I may form other
+seemingly simple beliefs, to which the term expectation seems less
+clearly applicable. Thus, on waking in the morning and finding the
+ground covered with snow, my imagination moves backwards, as in the
+process of memory, and realizes<span class='pagenum'><a name="Page_309" id="Page_309">[Pg 309]</a></span> the spectacle of the softly falling
+snow-flakes in the hours of the night. The oral communication of others'
+experience, including the traditions of the race, enables me to set out
+from any present point of time, and reconstruct complex chains of
+experience of vast length lying beyond the bounds of my own personal
+recollection.</p>
+
+<p>I need not here discuss what the exact nature of such beliefs is. J.S.
+Mill identifies them with expectations. Thus, according to him, my
+belief in the nocturnal snowstorm is the assurance that I should have
+seen it had I waited up during the night. So my belief in Cicero's
+oratory resolves itself into the conviction that I should have heard
+Cicero under certain conditions of time and place, which is identical
+with my expectation that I shall hear a certain speaker to-morrow if I
+go to the House of Commons.<a name="FNanchor_140_140" id="FNanchor_140_140"></a><a href="#Footnote_140_140" class="fnanchor">[140]</a> However this be, the thing to note is
+that such retrospective beliefs, when once formed, tend to approximate
+in character to recollections. This is true even of new beliefs in
+recent events directly made known by present objective consequences or
+signs, as the snowstorm. For in this case there is commonly no conscious
+comparison of the present signs with previously known signs, but merely
+a direct quasi-mnemonic passage of mind from the present fact to its
+antecedent. And it is still more true of long-entertained retrospective
+beliefs. When, for example, the original grounds of an historical
+hypothesis are lost sight of, and after the<span class='pagenum'><a name="Page_310" id="Page_310">[Pg 310]</a></span> belief has hardened and
+solidified by time, it comes to look much more like a recollection than
+an expectation. As a matter of fact, we have seen, when studying the
+illusions of memory, that our personal experience does become confused
+with that of others. And one may say that all long-cherished
+retrospective beliefs tend to become assimilated to recollections.</p>
+
+<p>Here then, again, there seems to be room for illusion to arise. Even in
+the case of a recent past event, directly made known by present
+objective signs, the mind is liable to err just as in the case of
+forecasting an immediately approaching event. And such error has all the
+force of an illusion: its contradiction is almost as great a shock as
+that of a recollection. When, for example, I enter my house, and see a
+friend's card lying on the table, I so vividly represent to myself the
+recent call of my friend, that when I learn the card is an old one which
+has accidentally been put on the table, I experience a sense of
+disillusion very similar to that which attends a contradicted
+perception. The early crude stages of physical science abundantly
+illustrate the genesis of such illusions.</p>
+
+<p>It may be added that if there be any feeling present in the mind at the
+time, the barest suggestion of something having happened will suffice to
+produce the immediate assurance. Thus, an angry person is apt to hastily
+accuse another of having done certain things on next to no evidence. The
+love of the marvellous seems to have played a conspicuous part in
+building up and sustaining the fanciful hypotheses which mark the dawn
+of physical science.</p>
+
+<p>Verbal suggestion is a common mode of produc<span class='pagenum'><a name="Page_311" id="Page_311">[Pg 311]</a></span>ing this semblance of a
+recollected event. By means of the narrative style, it vividly suggests
+the idea that the events described belong to the past, and excites the
+imagination to a retrospective construction of them as though they were
+remembered events. Hence the power of works of fiction on the ordinary
+mind. Even when there is no approach to an illusion of perception, or to
+one of memory in the strict sense, the reading of a work of fiction
+begets at the moment a retrospective belief that has a certain
+resemblance to a recollection.</p>
+
+<p>All such illusions as those just illustrated, if not afterwards
+corrected, tend to harden into yet more distinctly "intuitive" errors.
+Thus, for example, one of the crude geological hypotheses, of which Sir
+Charles Lyell tells us,<a name="FNanchor_141_141" id="FNanchor_141_141"></a><a href="#Footnote_141_141" class="fnanchor">[141]</a> would, by the mere fact of being kept
+before the mind, tend to petrify into a hard fixed belief. And this
+process of hardening is seen strikingly illustrated in the case of
+traditional errors, especially when these fall in with our own emotional
+propensities. Our habitual representations of the remote historical past
+are liable to much the same kind of error as our recollections of early
+personal experience. The wrong statements of others and the promptings
+of our own fancies may lead in the first instance to a filling up of the
+remote past with purely imaginary shapes. Afterwards the particular
+origin of the belief is forgotten, and the assurance assumes the aspect
+of a perfectly intuitive conviction. The hoary traditional myths
+respecting the golden age, and so on, and the<span class='pagenum'><a name="Page_312" id="Page_312">[Pg 312]</a></span> persistent errors of
+historians under the sway of a strong emotional bias, illustrate such
+illusions.</p>
+
+<p>So much as to simple illusions of belief, or such as involve single
+representations only. Let us now pass to compound illusions, which
+involve a complex group of representations.</p>
+
+
+<p class='center'>B. <i>Compound Illusory Belief.</i></p>
+
+<p>A familiar example of a compound belief is the belief in a permanent or
+persistent individual object of a certain character. Such an idea,
+whatever its whole meaning may be&mdash;and this is a disputed point in
+philosophy&mdash;certainly seems to include a number of particular
+representations, corresponding to direct personal recollections, to the
+recollections of others, and to numerous anticipations of ourselves and
+of others. And if the object be a living creature endowed with feelings,
+our idea of it will contain, in addition to these represented
+perceptions of ourselves or of others, a series of represented insights,
+namely, such as correspond to the inner experience of the being, so far
+as this is known or imagined.</p>
+
+<p>It would thus seem that the idea which we habitually carry about with us
+respecting a complex individual object is a very composite idea. In
+order to see this more fully, let us inquire into what is meant by our
+belief in a person. My idea of a particular friend contains, among other
+things, numbers of vague representations of his habitual modes of
+feeling and acting, and numbers of still more vague expectations of how
+he will or might feel and act in certain circumstances.<span class='pagenum'><a name="Page_313" id="Page_313">[Pg 313]</a></span></p>
+
+<p>Now, it is plain that such a composite idea must have been a very slow
+growth, involving, in certain stages of its formation, numerous
+processes of inference or quasi-inference from the past to the future.
+But in process of time these elements fuse inseparably: the directly
+known and the inferred no longer stand apart in my mind; my whole
+conception of the individual as he has been, is, and will be, seems one
+indivisible cognition; and this cognition is so firmly fixed and
+presents itself so instantaneously to the mind when I think of the
+object, that it has all the appearance of an intuitive conviction.</p>
+
+<p>If this is a fairly accurate description of the structure of these
+compound representations and of their attendant beliefs, it is easy to
+see how many openings for error they cover. To begin with, my
+representation of so complex a thing as a concrete personality must
+always be exceedingly inadequate and fragmentary. I see only a few
+facets of the person's many-sided mind and character. And yet, in
+general, I am not aware of this, but habitually identify my
+representation with the totality of the object.</p>
+
+<p>More than this, a little attention to the process by which these
+compound beliefs arise will disclose the fact that this apparently
+adequate representation of another has arisen in part by other than
+logical processes. If the blending of memory and expectation were simply
+a mingling of facts with correct inferences from these, it might not
+greatly matter; but it is something very different from this. Not only
+has our direct observation of the person been very limited, even that
+which we have been able to see has not<span class='pagenum'><a name="Page_314" id="Page_314">[Pg 314]</a></span> been perfectly mirrored in our
+memory. It has already been remarked that recollection is a selective
+process, and this truth is strikingly illustrated in the growth of our
+enduring representations of things. What stamps itself on my memory is
+what surprised me or what deeply interested me at the moment. And then
+there are all the risks of mnemonic illusion to be taken into account as
+well. Thus, my idea of a person, so far even as it is built up on a
+basis of direct personal recollection, is essentially a fragmentary and
+to some extent a misleading representation.</p>
+
+<p>Nor is this all. My habitual idea of a person is a resultant of forces
+of memory conjoined with other forces. Among these are to be reckoned
+the influence of illusory perception or insight, my own and that of
+others. The amount of misinterpretation of the words and actions of a
+single human being during the course of a long acquaintance must be very
+considerable. To these must be added the effect of erroneous single
+expectations and reconstructions of past experiences, in so far as these
+have not been distinctly contradicted and dissipated. All these errors,
+connected with single acts of observing or inferring the feelings and
+doings of another, have their effect in distorting the subsequent total
+representation of the person.</p>
+
+<p>Finally, we must include a more distinct ingredient of active illusion,
+namely, all the complex effects of the activity of imagination as led,
+not by fact and experience, but by feeling and desire. Our permanent
+idea of another reflects all that we have fondly imagined the person
+capable of doing, and thus is<span class='pagenum'><a name="Page_315" id="Page_315">[Pg 315]</a></span> made up of an ideal as well as a real
+actually known personality. And this result of spontaneous imagination
+must be taken to include the ideals entertained by others who are likely
+to have influenced us by their beliefs.<a name="FNanchor_142_142" id="FNanchor_142_142"></a><a href="#Footnote_142_142" class="fnanchor">[142]</a></p>
+
+<p>Enough has probably been said to show how immensely improbable it is
+that our permanent cognition of so complex an object as a particular
+human being should be at all an accurate representation of the reality,
+how much of the erroneous is certain to get mixed up with the true. And
+this being so, we may say that our apparently simple direct cognition of
+a given person, our assurance of what he is and will continue to be, is
+to some extent illusory.</p>
+
+
+<p class='center'><i>Illusion of Self-Esteem.</i></p>
+
+<p>Let us now pass to another case of compound representation, where the
+illusory element is still more striking. I refer to the idea of self
+which each of us habitually carries about with him. Every man's opinion
+of himself, as a whole, is a very complex mental product, in which facts
+known by introspection no doubt play a part, but probably only a very
+subordinate part. It is obvious, from what has been said about the
+structure of our habitual representations of other individuals, that our
+ordinary representation of ourselves will be tinged with that mass of
+error which we have found to be connected<span class='pagenum'><a name="Page_316" id="Page_316">[Pg 316]</a></span> with single acts of
+introspection, recollections of past personal experience, and illusory
+single expectations of future personal experiences. How large an opening
+for erroneous conviction here presents itself can only be understood by
+a reference to certain deeply fixed impulses and feelings connected
+with, the very consciousness of self, and favouring what I have marked
+off as active illusion. I shall try to show very briefly that each man's
+intuitive persuasion of his own powers, gifts, or importance&mdash;in brief,
+of his own particular value, contains, from the first, a palpable
+ingredient of active illusion.</p>
+
+<p>Most persons, one supposes, have with more or less distinct
+consciousness framed a notion of their own value, if not to the world
+generally, at least to themselves. And this notion, however undefined it
+may be, is held to with a singular tenacity of belief. The greater part
+of mankind, indeed, seem never to entertain the question whether they
+really possess points of excellence. They assume it as a matter
+perfectly self-evident, and appear to believe in their vaguely conceived
+worth on the same immediate testimony of consciousness by which they
+assure themselves of their personal existence. Indeed, the conviction of
+personal consequence may be said to be a constant factor in most men's
+consciousness. However restrained by the rules of polite intercourse, it
+betrays its existence and its energy in innumerable ways. It displays
+itself most triumphantly when the mind is suddenly isolated from other
+minds, when other men unite in heaping neglect and contempt on the
+believer's head. In these moments he proves an almost heroic strength of
+con<span class='pagenum'><a name="Page_317" id="Page_317">[Pg 317]</a></span>fidence, believing in himself and in his claims to careful
+consideration when all his acquaintance are practically avowing their
+disbelief.</p>
+
+<p>The intensity of this belief in personal value may be observed in very
+different forms. The young woman who, quite independently of others'
+opinion, and even in defiance of it, cherishes a conviction that her
+external attractions have a considerable value; the young man who, in
+the face of general indifference, persists in his habit of voluble talk
+on the supposition that he is conferring on his fellow-creatures the
+fruits of profound wisdom; and the man of years whose opinion of his own
+social importance and moral worth is quite disproportionate to the
+estimation which others form of his claims&mdash;these alike illustrate the
+force and pertinacity of the belief.</p>
+
+<p>There are, no doubt, many exceptions to this form of self-appreciation.
+In certain robust minds, but little given to self-reflection, the idea
+of personal value rarely occurs. And then there are timid, sensitive
+natures that betray a tendency to self-distrust of all kinds, and to an
+undue depreciation of personal merit. Yet even here traces of an impulse
+to think well of self will appear to the attentive eye, and one can
+generally recognize that this impulse is only kept down by some other
+stronger force, as, for example, extreme sensitiveness to the judgment
+of others, great conscientiousness, and so on. And however this be, it
+will be allowed that the average man rates himself highly.</p>
+
+<p>It is to be noticed that this persuasion of personal value or excellence
+is, in common, very vague. A man<span class='pagenum'><a name="Page_318" id="Page_318">[Pg 318]</a></span> may have a general sense of his own
+importance without in the least being able to say wherein exactly his
+superiority lies. Or, to put it another way, he may have a strong
+conviction that he stands high in the scale of morally deserving
+persons, and yet be unable to define his position more nearly. Commonly,
+the conviction seems to be only definable as an assurance of a
+superlative of which the positive and comparative are suppressed. At
+most, his idea of his moral altitude resolves itself into the
+proposition, "I am a good deal better than Mr. A. or Mr. B." Now, it is
+plain that in these intuitive judgments on his own excellence, the man
+is making an assertion with respect, not only to inner subjective
+feelings which he only can be supposed to know immediately, but also to
+external objective facts which are patent to others, namely, to certain
+active tendencies and capabilities, to the direction of external conduct
+in certain lines.<a name="FNanchor_143_143" id="FNanchor_143_143"></a><a href="#Footnote_143_143" class="fnanchor">[143]</a> Hence, if the assertion is erroneous, it will be
+in plain contradiction to others' perceptions of his powers or moral
+endowments. And this is what we actually find. A man's self-esteem, in a
+large preponderance of cases, is plainly in excess of others' esteem of
+him. What the man conceives himself to be differs widely from what
+others conceive him to be.</p>
+
+<p>
+<span style="margin-left: 1em;">"Oh wad some power the giftie gie us,</span><br />
+<span style="margin-left: 1.5em;">To see oursels as others see us!"</span><br />
+</p>
+
+<p>Now, whence comes this large and approximately uniform discrepancy
+between our self-esteem and<span class='pagenum'><a name="Page_319" id="Page_319">[Pg 319]</a></span> others' esteem of us? By trying to answer
+this question we shall come to understand still better the processes by
+which the most powerful forms of illusion are generated.</p>
+
+<p>It is, I think, a matter of every-day observation that children manifest
+an apparently instinctive disposition to magnify self as soon as the
+vaguest idea of self is reached. It is very hard to define this feeling
+more precisely than by terming it a rudimentary sense of personal
+importance. It may show itself in very different ways, taking now a more
+active form, as an impulse of self-assertion, and a desire to enforce
+one's own will to the suppression of others' wills, and at another time
+wearing the appearance of a passive emotion, an elementary form of
+<i>amour propre</i>. And it is this feeling which forms the germ of the
+self-estimation of adults. For in truth all attribution of value
+involves an element of feeling, as respect, and of active desire, and
+the ascription of value to one's self is in its simplest form merely the
+expression of this state of mind.</p>
+
+<p>But how is it, it may be asked, that this feeling shows itself
+instinctively as soon as the idea of self begins to arise in
+consciousness? The answer to this question is to be found, I imagine, in
+the general laws of mental development. All practical judgments like
+that of self-estimation are based on some feeling which is developed
+before it; and, again, the feeling itself is based on some instinctive
+action which, in like manner, is earlier than the feeling. Thus, for
+example, an Englishman's judgment that his native country is of
+paramount value springs out of a long-existent senti<span class='pagenum'><a name="Page_320" id="Page_320">[Pg 320]</a></span>ment of patriotism,
+which sentiment again may be regarded as having slowly grown up about
+the half-blindly followed habit of defending and furthering the
+interests of one's nation or tribe. In a similar way, one suspects, the
+feeling of personal worth, with its accompanying judgment, is a product
+of a long process of instinctive action.</p>
+
+<p>What this action is it is scarcely necessary to remind the reader. Every
+living organism strives, or acts as if it consciously strove, to
+maintain its life and promote its well-being. The actions of plants are
+clearly related to the needs of a prosperous existence, individual first
+and serial afterwards. The movements of the lower animals have the same
+end. Thus, on the supposition that man has been slowly evolved from
+lower forms, it is clear that the instinct of self-promotion must be the
+deepest and most ineradicable element of his nature, and it is this
+instinct which directly underlies the rudimentary sentiment of
+self-esteem of which we are now treating.</p>
+
+<p>This instinct will appear, first of all, as the unreflecting organized
+habit of seeking individual good, of aiming at individual happiness, and
+so of pushing on the action of the individual will. This impulse shows
+itself in distinct form as soon as the individual is brought into
+competition with another similarly constituted being. It is the force
+which displays itself in all opposition and hostility, and it tends to
+limit and counteract the gregarious instincts of the race. In the next
+place, as intelligence expands, this instinctive action becomes
+conscious pursuit of an end, and at this stage the thing pursued
+attracts to itself<span class='pagenum'><a name="Page_321" id="Page_321">[Pg 321]</a></span> a sentiment. The individual now consciously desires
+his own happiness as contrasted with that of others, knowingly aims at
+enlarging his own sphere of action to the diminution of others' spheres.
+Here we have the nascent sentiment of self-esteem, on which all later
+judgments respecting individual importance are, in part at least,
+founded.</p>
+
+<p>Thus, we see that long before man had arrived at an idea of self there
+had been growing up an emotional predisposition to think well of self.
+And in this way we may understand how it is that this sentiment of
+self-esteem shows itself immediately and instinctively in the child's
+mind as soon as its unfolding consciousness is strong enough to grasp
+the first rough idea of personal existence. Far down, so to speak, below
+the surface of distinct consciousness, in the intricate formation of
+ganglion-cell and nerve-fibre, the connections between the idea of self
+and this emotion of esteem have been slowly woven through long ages of
+animal development.</p>
+
+<p>Here, then, we seem to have the key to the apparently paradoxical fact
+that a man, with all his superior means of studying his own feelings,
+commonly esteems himself, in certain respects at least, less accurately
+than a good external observer would be capable of doing. In forming an
+opinion of ourselves we are exposed to the full force of a powerful
+impulse of feeling. This impulse, acting as a bias, enters more or less
+distinctly into our single acts of introspection, into our attempts to
+recall our past doings, into our insights into the meaning of others'
+words and actions as related to ourselves (forming the natural
+disposition<span class='pagenum'><a name="Page_322" id="Page_322">[Pg 322]</a></span> to enjoy flattery), and finally into our wild dreams as to
+our future achievements. It is thus the principal root of that gigantic
+illusion of self-conceit, which has long been recognized by practical
+sense as one of the greatest obstacles to social action; and by art as
+one of the most ludicrous manifestations of human weakness.</p>
+
+<p>If there are all these openings for error in the beliefs we go on
+entertaining respecting individual things, including ourselves, there
+must be a yet larger number of such openings in those still more
+compound beliefs which we habitually hold respecting collections or
+classes of things. A single illusion of perception or of memory may
+suffice to give rise to a wholly illusory belief in a class of objects,
+for example, ghosts. The superstitious beliefs of mankind abundantly
+illustrate this complexity of the sources of error. And in the case of
+our every-day beliefs respecting real classes of objects, these sources
+contribute a considerable quota of error. We may again see this by
+examining our ordinary beliefs respecting our fellow-men.</p>
+
+<p>A moment's consideration will show that our prevailing views respecting
+any section of mankind, say our fellow-countrymen, or mankind at large,
+correspond at best to a very loose process of reasoning. The accidents
+of our personal experience and opportunities of observation, the
+traditions which coloured our first ideas, the influence of our dominant
+feelings in selecting for attention and retention certain aspects of the
+complex object, and in idealizing this object,&mdash;these sources of passive
+and active illusion, must, to say the least, have had as much to do with
+our present solidified and seemingly "intuitive" knowledge as anything
+that can<span class='pagenum'><a name="Page_323" id="Page_323">[Pg 323]</a></span> be called the exercise of individual judgment and reasoning
+power.</p>
+
+<p>The force of this observation and the proof that such widely generalized
+beliefs are in part illusory, is seen in the fact that men of unlike
+experience and unlike temperament form such utterly dissimilar views of
+the same object. Thus, as Mr. Spencer has shown,<a name="FNanchor_144_144" id="FNanchor_144_144"></a><a href="#Footnote_144_144" class="fnanchor">[144]</a> in looking at
+things national there may be not only a powerful patriotic bias at work
+in the case of the vulgar Philistine, but also a distinctly
+anti-patriotic bias in the case of the over-fastidious seeker after
+culture. And I need hardly add that the different estimates of mankind
+held with equal assurance by the cynic, the misanthropist, and the
+philanthropic vindicator of his species, illustrate a like diversity of
+the psychological conditions of belief.</p>
+
+<p>Finally, illusion may enter into that still wider collection of beliefs
+which make up our ordinary views of life and the world as a whole. Here
+there reflect themselves in the plainest manner the accidents of our
+individual experience and the peculiar errors to which our intellectual
+and emotional conformation disposes us. The world is for us what we feel
+it to be; and we feel it to be the cause of our particular emotional
+experience. Just as we have found that our environment helps to
+determine our idea of self and personal continuity, so, conversely, our
+inner experience, our remembered or imagined joys and sorrows throw a
+reflection on the outer world, giving it its degree of worth. Hence the
+contradictory, and consequently to some extent at least illusory, views
+of the optimist and the pessimist,<span class='pagenum'><a name="Page_324" id="Page_324">[Pg 324]</a></span> "intuitions" which, I have tried to
+show elsewhere, are connected with deeply rooted habits of feeling, and
+are antecedent to all reasoned philosophic systems.</p>
+
+<p>If proof were yet wanted that these wide-embracing beliefs may to some
+extent be illusory, it would be found in the fact that they can be
+distinctly coloured by a temporary mood or mental tone. As I have more
+than once had occasion to remark, a feeling when present tends to colour
+all the ideas of the time. And when out of sorts, moody, and
+discontented, a man is prone to find a large objective cause of his
+dissatisfaction in a world out of joint and not moving to his mind.</p>
+
+<p>It is evident that all the permanent beliefs touched on in this chapter
+must constitute powerful predispositions with respect to any particular
+act of perception, insight, introspection, or recollection. In other
+words, these persistent beliefs, so far as individual or personal, are
+but another name for those fixed habits of mind which, in the case of
+each one of us, constitute our intellectual bias, and the source of the
+error known as personal equation. And it may be added that, just as
+these erroneous beliefs existing in the shape of fixed prejudices
+constitute a bias to new error, so they act as powerful resisting forces
+in relation to new truth and the correction of error.</p>
+
+<p>In comparing these illusions of belief with those of perception and
+memory, we cannot fail to notice their greater compass or range, in
+other words, the greater extent of the region of fact misrepresented.
+Even if they are less forcible and irresistible than these errors, they
+clearly make up for this by the area which they cover.<span class='pagenum'><a name="Page_325" id="Page_325">[Pg 325]</a></span></p>
+
+<p>Another thing to be observed with respect to these comprehensive beliefs
+is that where, as here, so many co-operant conditions are at work, the
+whole amount of common objective agreement is greatly reduced. In other
+words, individual peculiarities of intellectual conformation, emotional
+temperament, and experience have a far wider scope for their influence
+in these beliefs than they have in the case of presentative cognitions.
+At the same time, it is noteworthy that error much more rapidly
+propagates itself here than in the case of our perceptions or
+recollections. As we have seen, these beliefs all include much more than
+the results of the individual's own experience. They offer a large field
+for the influence of personal ascendency, of the contagion of sympathy,
+and of authority and tradition. As a consequence of this, the illusions
+of belief are likely to be far more persistent than those of perception
+or of memory; for not only do they lose that salutary process of
+correction which comparison with the experience of others affords, but
+they may even be strengthened and upheld to some extent by such social
+influences.</p>
+
+<p>And here the question might seem to obtrude itself, whether, in relation
+to such a fluctuating mass of belief as that just reviewed, in which
+there appears to be so little common agreement, we can correctly speak
+of anything as objectively determinable. If illusion and error as a
+whole are defined by a reference to what is commonly held true and
+certain, what, it may be asked, becomes of the so-called illusions of
+belief?</p>
+
+<p>This question will have to be fully dealt with in the following chapter.
+Here it may be sufficient to<span class='pagenum'><a name="Page_326" id="Page_326">[Pg 326]</a></span> remark that amid all this apparent
+deviation of belief from a common standard of truth, there is a clear
+tendency to a rational consensus. Thought, by disengaging what is really
+matter of permanent and common cognition, both in the individual and
+still more in the class,<a name="FNanchor_145_145" id="FNanchor_145_145"></a><a href="#Footnote_145_145" class="fnanchor">[145]</a> and fixing this quantum of common
+cognition in the shape of accurate definitions and universal
+propositions, is ever fighting against and restraining the impulses of
+individual imagination towards dissociation and isolation of belief. And
+this same process of scientific control of belief is ever tending to
+correct widespread traditional forms of error, and to erect a new and
+better standard of common cognition.</p>
+
+<p>This scientific regulation of belief only fails where the experiences
+which underlie the conceptions are individual, variable, and subjective.
+Hence there is no definite common conception of the value of life and of
+the world, just because the estimate of this value must vary with
+individual circumstances, temperament, etc. All that can be looked for
+here in the way of a common standard or norm is a rough average
+estimate. And this common-sense judgment serves practically as a
+sufficient criterion of truth, at least in relation to such extreme
+one-sidedness of view as approaches the abnormal, that is to say, one of
+the two poles of irrational exaltation, or "joy-madness," and<span class='pagenum'><a name="Page_327" id="Page_327">[Pg 327]</a></span> abject
+melancholy, which, appear among the phenomena of mental disease.<a name="FNanchor_146_146" id="FNanchor_146_146"></a><a href="#Footnote_146_146" class="fnanchor">[146]</a><span class='pagenum'><a name="Page_328" id="Page_328">[Pg 328]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+<h2>CHAPTER XII.</h2>
+
+<h4>RESULTS.</h4>
+
+
+<p>The foregoing study of illusions may not improbably have had a
+bewildering effect on the mind of the reader. To keep the mental eye,
+like the bodily eye, for any time intently fixed on one object is apt to
+produce a feeling of giddiness. And in the case of a subject like
+illusion, the effect is enormously increased by the disturbing character
+of the object looked at. Indeed, the first feeling produced by our
+survey of the wide field of illusory error might be expressed pretty
+accurately by the despondent cry of the poet&mdash;</p>
+
+<p>
+<span style="margin-left: 1em;">"Alas! it is delusion all:</span><br />
+<span style="margin-left: 1.5em;">The future cheats us from afar,</span><br />
+<span style="margin-left: 1.5em;">Nor can we be what we recall,</span><br />
+<span style="margin-left: 1.5em;">Nor dare we think on what we are."</span><br />
+</p>
+
+<p>It must be confessed that our study has tended to bring home to the mind
+the wide range of the illusory and unreal in our intellectual life. In
+sense-perception, in the introspection of the mind's own feelings, in
+the reading of others' feelings, in memory, and finally in belief, we
+have found a large field for illusory cognition. And while illusion has
+thus so great a depth in the individual mind, it has a no less striking<span class='pagenum'><a name="Page_329" id="Page_329">[Pg 329]</a></span>
+breadth or extent in the collective human mind. No doubt its grosser
+forms manifest themselves most conspicuously in the undisciplined mind
+of the savage and the rustic; yet even the cultivated mind is by no
+means free from its control. In truth, most of the illusions illustrated
+in this work are such as can be shared in by all classes of mind.</p>
+
+<p>In view of this wide far-reaching area of ascertained error, the mind
+naturally asks, What are the real limits of illusory cognition, and how
+can we be ever sure of having got beyond them? This question leads us on
+to philosophical problems of the greatest consequence, problems which
+can only be very lightly touched in this place. Before approaching
+these, let us look back a little more carefully and gather up our
+results, reflect on the method which we have been unconsciously
+adopting, and inquire how far this scientific mode of procedure will
+take us in determining what is the whole range of illusory cognition.</p>
+
+<p>We have found an ingredient of illusion mixed up with all the popularly
+recognized forms of immediate knowledge. Yet this ingredient is not
+equally conspicuous in all cases. First of all, illusion varies very
+considerably in its degree of force and persistence. Thus, in general, a
+presentative illusion is more coercive than a representative; an
+apparent reality present to the mind is naturally felt to be more
+indubitable than one absent and only represented. On the other hand, a
+representative illusion is often more enduring than a presentative, that
+is to say, less easily found out. It is to be added that a good deal of
+illusion is only partial, there being throughout an under-current of<span class='pagenum'><a name="Page_330" id="Page_330">[Pg 330]</a></span>
+rational consciousness, a gentle play of self-criticism, which keeps the
+error from developing into a perfect self-delusion. This remark applies
+not only to the innocent illusions of art, but also to many of our
+every-day illusions, both presentative and representative. In many
+cases, indeed, as, for example, in looking at a reflection in a mirror,
+the illusion is very imperfect, remaining in the nascent stage.</p>
+
+<p>Again, a little attention to the facts here brought together will show
+that the proportion of illusory to real knowledge is far from being the
+same in each class of immediate or quasi-immediate cognition. Thus, with
+respect to the great distinction between presentative and representative
+knowledge, it is to be observed that, in so far as any act of cognition
+is, strictly speaking, presentative, it does not appear to admit of
+error. The illusions of perception are connected with the representative
+side of the process, and are numerous just because this is so extensive.
+On the other hand, in introspection, where the scope of independent
+representation is so limited, the amount of illusion is very
+inconsiderable, and may in practice be disregarded. So again, to take a
+narrower group of illusions, we find that in the recalling of distant
+events the proportion of error is vastly greater than in the recalling
+of near events.</p>
+
+<p>So much as to the extent of illusion as brought to light by our
+preceding study. Let us now glance at the conclusions obtained
+respecting its nature and its causes.<span class='pagenum'><a name="Page_331" id="Page_331">[Pg 331]</a></span></p>
+
+<p class='center'><i>Causes of Illusion.</i></p>
+
+<p>Looking at illusion as a whole, and abstracting from the differences of
+mental mechanism in the processes of perception, memory, etc., we may
+say that the <i>rationale</i> or mode of genesis of illusion is very much the
+same throughout. Speaking broadly, one may describe all knowledge as a
+correspondence of representation with fact or experience, or as a stable
+condition of the representation which cannot be disturbed by new
+experiences. It does not matter, for our present purpose, whether the
+fact represented is supposed to be directly present, as in presentative
+cognition; or to be absent, either as something past or future, or
+finally as a "general fact," that is to say, the group of facts (past
+and future) embodied in a universal proposition.<a name="FNanchor_147_147" id="FNanchor_147_147"></a><a href="#Footnote_147_147" class="fnanchor">[147]</a></p>
+
+<p>In general this accordance between our representations and facts is
+secured by the laws of our intellectual mechanism. It follows from the
+principles of association that our simple experiences, external and
+internal, will tend to reflect themselves in perception, memory,
+expectation, and general belief, in the very time-connections in which
+they actually occur. To put it briefly, facts which occur together will
+in general be represented together, and they will be the more perfectly
+co-represented in proportion to the frequency of this concurrence.<span class='pagenum'><a name="Page_332" id="Page_332">[Pg 332]</a></span></p>
+
+<p>Illusion, as distinguished from correct knowledge, is, to put it
+broadly, deviation of representation from fact. This is due in part to
+limitations and defects in the intellectual mechanism itself, such as
+the imperfections of the activities of attention, discrimination, and
+comparison, in relation to what is present. Still more is it due to the
+control of our mental processes by association and habit. These forces,
+which are at the very root of intelligence, are also, in a sense, the
+originators of error. Through the accidents of our experience or the
+momentary condition of our reproductive power, representations get
+wrongly grouped with presentations and with one another; wrongly
+grouped, that is to say, according to a perfect or ideal standard,
+namely, that the grouping should always exactly agree with the order of
+experience as a whole, and the force of cohesion be proportionate to the
+number of the conjunctions of this experience.</p>
+
+<p>This great source of error has been so abundantly illustrated under the
+head of Passive Illusions that I need not dwell on it further. It is
+plain that a passive error of perception, or of expectation, is due in
+general to a defective grouping of elements, to a grouping which
+answers, perhaps, to the run of the individual's actual experience, but
+not to a large and complete common experience.<a name="FNanchor_148_148" id="FNanchor_148_148"></a><a href="#Footnote_148_148" class="fnanchor">[148]</a> Similarly, an
+illusory general belief is plainly a welding together of elements (here
+concepts, answering to innumerable representative images) in
+disagreement with the permanent connections of experience. Even a
+passive illusion of memory, in so<span class='pagenum'><a name="Page_333" id="Page_333">[Pg 333]</a></span> far as it involves a rearrangement of
+successive representations, shows the same kind of defect.</p>
+
+<p>In the second place, this incorrect grouping maybe due, not to defects
+in attention and discrimination, combined with insufficiently grounded
+association, but to the independent play of constructive imagination and
+the caprices of feeling. This is illustrated in what I have called
+Active Illusions, whether the excited perceptions and the hallucinations
+of sense, or the fanciful projections of memory or of expectation. Here
+we have a force directly opposed to that of experience. Active illusion
+arises, not through the imperfections of the intellectual mechanism, but
+through a palpable interference with this mechanism. It is a regrouping
+of elements which simulates the form of a suggestion by experience, but
+is, in reality, the outcome of the individual mind's extra-intellectual
+impulses.</p>
+
+<p>We see, then, that, in spite of obvious differences in the form, the
+process in all kinds of immediate cognition is fundamentally identical.
+It is essentially a bringing together of elements, whether similar or
+dissimilar and associated by a link of contiguity, and a viewing of
+these as connected parts, of a whole; it is a process of synthesis. And
+illusion, in all its forms, is bad grouping or carelessly performed
+synthesis. This holds good even of the simplest kinds of error in which
+a presentative element is wrongly classed; and it holds good of those
+more conspicuous errors of perception, memory, expectation, and compound
+belief, in which representations connect themselves in an order not
+perfectly answering to the objective order.<span class='pagenum'><a name="Page_334" id="Page_334">[Pg 334]</a></span></p>
+
+<p>This view of the nature and causes of illusion is clearly capable of
+being expressed in physical language. Bad grouping of psychical elements
+is equivalent to imperfect co-ordination of their physical, that is to
+say, nervous, conditions, imperfect in the evolutionist's sense, as not
+exactly according with external relations. So far as illusions of
+suggestion (passive illusions) are concerned, the error is connected
+with organized tendencies, due to a limited action of experience. On the
+other hand, illusions of preconception (active illusions) usually
+involve no such deeply fixed or permanent organic connections, but
+merely a temporary confluence of nerve-processes.<a name="FNanchor_149_149" id="FNanchor_149_149"></a><a href="#Footnote_149_149" class="fnanchor">[149]</a> The nature of the
+physical process is best studied in the case of errors of
+sense-perception. Yet we may hypothetically argue that even in the case
+of the most complex errors, as those of memory and of belief, there is
+implied a deviation in the mode of connection of nervous structures
+(whether the connection be permanent or temporary) from the external
+order of facts.</p>
+
+<p>And now we are in a position to see whether illusion is ultimately
+distinguishable from other modes of error, namely, those incident to
+conscious processes of reasoning. It must have been plain to an
+attentive reader throughout our exposition that, in spite of our
+provisional distinction, no sharp line can be drawn between much of
+what, on the surface, looks like immediate knowledge, and consciously
+derived or inferred knowledge. On its objective side, reasoning may be<span class='pagenum'><a name="Page_335" id="Page_335">[Pg 335]</a></span>
+roughly defined as a conscious transition of mind from certain facts or
+relations of facts to other facts or relations recognized as similar.
+According to this definition, a fallacy would be a hasty, unwarranted
+transition to new cases not identical with the old. And a good part of
+immediate knowledge is fundamentally the same, only that here, through
+the exceptional force of association and habit, the transition is too
+rapid to be consciously recognized. Consequently, illusion becomes
+identified at bottom with fallacious inference: it may be briefly
+described as collapsed inference. Thus, illusory perception and
+expectation are plainly a hasty transition of mind from old to new, from
+past to present, conjunctions of experience.<a name="FNanchor_150_150" id="FNanchor_150_150"></a><a href="#Footnote_150_150" class="fnanchor">[150]</a> And, as we have seen,
+an illusory general belief owes its existence to a coalescence of
+representations of known facts or connections with products of
+imagination which simulate the appearance of inferences from these
+facts.</p>
+
+<p>In the case of memory, in so far as it is not aided<span class='pagenum'><a name="Page_336" id="Page_336">[Pg 336]</a></span> by reasoning from
+present signs, there seems to be nothing like a movement of inference.
+It is evident, indeed, that memory is involved in and underlies every
+such transition of thought. Illusions of memory illustrate rather a
+process of wrong classing, that is to say, of wrongly identifying the
+present mental image with past fact, which is the initial step in all
+inference. In this way they closely resemble those slight errors of
+perception which are due to erroneous classing of sense-impressions. But
+since the intellectual process involved in assimilating mental elements
+is very similar to that implied in assimilating complex groups of such
+elements, we may say that even in these simple kinds of error there is
+something which resembles a wrong classing of relations, something,
+therefore, which approximates in character to a fallacy.</p>
+
+<p>By help of this brief review of the nature and causes of illusion, we
+see that in general it may be spoken of as deviation of individual from
+common experience. This applies to passive illusion in so far as it
+follows from the accidents of individual experience, and it still more
+obviously applies to active illusion as due to the vagaries of
+individual feeling and constructive imagination. We might, perhaps,
+characterize all illusion as partial view, partial both in the sense of
+being incomplete, and in the other sense of being that to which the mind
+by its peculiar predispositions inclines. This being so, we may very
+roughly describe all illusion as abnormal. Just as hallucination, the
+most signal instance of illusion, is distinctly on the border-land of
+healthy and unhealthy mental life; just as dreams are in the direction
+of such unhealthy<span class='pagenum'><a name="Page_337" id="Page_337">[Pg 337]</a></span> mental action; so the lesser illusions of memory and
+so on are abnormal in the sense that they imply a departure from a
+common typical mode of intellectual action.</p>
+
+<p>It is plain, indeed, that this is the position we have been, taking up
+throughout our discussion of illusion. We have assumed that what is
+common and normal is true, or answers to what is objectively real. Thus,
+in dealing with errors of perception, we took for granted that the
+common percept&mdash;meaning by this what is permanent in the individual and
+the general experience&mdash;is at the same time the true percept. So in
+discussing the illusions of memory we estimated objective time by the
+judgment of the average man, free from individual bias, and apart from
+special circumstances favourable to error. Similarly, in the case of
+belief, true belief was held to be that which men in general, or in the
+long run, or on the average, hold true, as distinguished from what the
+individual under variable and accidental influences holds true. And even
+in the case of introspection we found that true cognition resolved
+itself into a consensus or agreement as to certain psychical facts.</p>
+
+
+<p class='center'><i>Criterion of Illusion.</i></p>
+
+<p>Now, it behoves us here to examine this assumption, with the view of
+seeing how far it is perfectly sound. For it may be that what is
+commonly held true does not in all cases strictly answer to the real, in
+which case our idea of illusion would have to be extended so as to
+include certain common beliefs. This question was partly opened up at
+the close of the last chapter.<span class='pagenum'><a name="Page_338" id="Page_338">[Pg 338]</a></span> It will be found that the full
+discussion of it carries us beyond the scientific point of view
+altogether. For the present, however, let us see what can be said about
+it from that standpoint of positive science to which we have hitherto
+been keeping.</p>
+
+<p>Now, if by common be meant what has been shared by all minds or the
+majority of minds up to a particular time, a moment's inspection of the
+process of correcting illusion will show that science assumes the
+possibility of a common illusion. In the history of discovery, the first
+assault on an error was the setting up of the individual against the
+society. The men who first dared to say that the sun did not move round
+the earth found to their cost what it was to fly in the face of a
+common, though illusory, perception of the senses.<a name="FNanchor_151_151" id="FNanchor_151_151"></a><a href="#Footnote_151_151" class="fnanchor">[151]</a></p>
+
+<p>If, however, by common be understood what is permanently and unshakably
+held true by men in proportion as their minds become enlightened, then
+science certainly does assume the truth of common perception and belief.
+Thus, the progress of the physical sciences may be described as a
+movement towards a new, higher, and more stable consensus of ideas and
+beliefs. In point of fact, the truths accepted by men of science already
+form a body of common belief for<span class='pagenum'><a name="Page_339" id="Page_339">[Pg 339]</a></span> those who are supposed by all to have
+the means of testing the value of their convictions. And the same
+applies to the successive improvements in the conceptions of the moral
+sciences, for example, history and psychology. Indeed, the very meaning
+of science appears to be a body of common cognition to which all minds
+converge in proportion to their capabilities and opportunities of
+studying the particular subject-matter concerned.</p>
+
+<p>Not only so, from a strictly scientific point of view it might seem
+possible to prove that common cognition, as defined above, must in
+general be true cognition. I refer here to the now familiar method of
+the evolutionist.</p>
+
+<p>According to this doctrine, which is a scientific method in so far as it
+investigates the historical developments of mind or the order of mental
+phenomena in time, cognition may be viewed as a part of the result of
+the interaction of external agencies and the organism, as an incident of
+the great process of adaptation, physical and psychical, of organism to
+environment. In thus looking at cognition, the evolutionist is making
+the assumption which all science makes, namely, that correct views are
+correspondences between internal (mental) relations and external
+(physical) relations, incorrect views disagreements between these
+relations. From this point of view he may proceed to argue that the
+intellectual processes must tend to conform to external facts. All
+correspondence, he tells us, means fitness to external conditions and
+practical efficiency, all want of correspondence practical incompetence.
+Consequently, those individuals in whom the corre<span class='pagenum'><a name="Page_340" id="Page_340">[Pg 340]</a></span>spondence was more
+complete and exact would have an advantage in the struggle for existence
+and so tend to be preserved. In this way the process of natural
+selection, by separately adjusting individual representations to
+actualities, would make them converge towards a common meeting-point or
+social standard of true cognition. That is to say, by eliminating or at
+least greatly circumscribing the region of individual illusion, natural
+selection would exclude the possibility of a persistent common illusion.</p>
+
+<p>Not only so, the evolutionist may say that this coincidence between
+common beliefs and true beliefs would be furthered by social as well as
+individual competition. A community has an advantage in the struggle
+with other communities when it is distinguished by the presence of the
+conditions of effective co-operation, such as mutual confidence. Among
+these conditions a body of true knowledge seems to be of the first
+importance, since conjoint action always presupposes common beliefs,
+and, to be effective action, implies that these beliefs are correct.
+Consequently, it may be argued, the forces at work in the action of man
+on man, of society on the individual, in the way of assimilating belief,
+must tend, in the long run, to bring about a coincidence between
+representations and facts. Thus, in another way, natural selection would
+help to adjust our ideas to realities, and to exclude the possibility of
+anything like a permanent common error.</p>
+
+<p>Yet once more, according to Mr. Herbert Spencer, the tendency to
+agreement between our ideas and the environment would be aided by what
+he calls the<span class='pagenum'><a name="Page_341" id="Page_341">[Pg 341]</a></span> direct process of adaptation. The exercise of a function
+tends to the development of that function. Thus, our acts of perception
+must become more exact by mere repetition. So, too, the representations
+and concepts growing out of perceptions must tend to approximate to
+external facts by the direct action of the environment on our physical
+and psychical organism; for external relations which are permanent will,
+in the long run, stamp themselves on our nervous and mental structure
+more deeply and indelibly than relations which are variable and
+accidental.</p>
+
+<p>It would seem, from all this, that so long as we are keeping to the
+scientific point of view, that is to say, taking for granted that there
+is something objectively real answering to our perceptions and
+conceptions, the question of the possibility of a universal or
+(permanently) common illusion does not arise. Yet a little more
+reflection will show us that it may arise in a way. So far as the
+logical sufficiency of the social consensus or common belief is accepted
+as scientifically proved, it is open to suspicion on strictly scientific
+grounds. The evolutionist's proof involves one or two assumptions which
+are not exactly true.</p>
+
+<p>In the first place, it is not strictly correct to say that all illusion
+involves a practical unfitness to circumstances. At the close of our
+investigation of particular groups of illusion, for example, those of
+perception and memory, it was pointed out that many of the errors
+reviewed were practically harmless, being either momentary and
+evanescent, or of such a character as not to lead to injurious action.
+And now, by glancing back over the field of illusion as a whole,<span class='pagenum'><a name="Page_342" id="Page_342">[Pg 342]</a></span> we may
+see the same thing. The day-dreams in which some people are apt to
+indulge respecting the remote future have little effect on their
+conduct. So, too, a man's general view of the world is often unrelated
+to his daily habits of life. It seems to matter exceedingly little, in
+general, whether a person take up the geocentric or the heliocentric
+conception of the cosmic structure, or even whether he adopt an
+optimistic or pessimistic view of life and its capabilities.</p>
+
+<p>So inadequate, indeed, does the agency of natural selection seem to be
+to eliminate illusion, that it may even be asked whether its tendency
+may not be sometimes to harden and fix rather than to dissolve and
+dissipate illusory ideas and beliefs. It will at once occur to the
+reader that the illusion of self-esteem, discussed in the last chapter,
+may have been highly useful as subserving individual self-preservation.
+In a similar way, it has been suggested by Schopenhauer that the
+illusion of the lover owes its force and historical persistence to its
+paramount utility for the preservation of the species. And to pass from
+a recurring individual to a permanently common belief, it is maintained
+by the same pessimist and his followers that what they regard as the
+illusion of optimism, namely, the idea that human life as a whole is
+good, grows out of the individual's irrational love of life, which is
+only the same instinctive impulse of self-preservation appearing as
+conscious desire. Once more, it has been suggested that the belief in
+free-will, even if illusory, would be preserved by the process of
+evolution, owing to its paramount utility in certain stages of moral
+development. All this seems to show at least the<span class='pagenum'><a name="Page_343" id="Page_343">[Pg 343]</a></span> possibility of a kind
+of illusion which would tend to perpetuate itself, and to appear as a
+permanent common belief.</p>
+
+<p>Now, so far as this is the case, so far as illusion is useful or only
+harmless, natural selection cannot, it is plain, be counted on to weed
+it out, keeping it within the narrow limits of the exceptional and
+individual. Natural selection gets rid of what is harmful only, and is
+indifferent to what is practically harmless.</p>
+
+<p>It may, however, still be said that the process of direct adaptation
+must tend to establish such a consensus of true belief. Now, I do not
+wish for a moment to dispute that the growth of intelligence by the
+continual exercise of its functions tends to such a consensus: this is
+assumed to be the case by everybody. What I want to point out is that
+there is no scientific proof of this position.</p>
+
+<p>The correspondence of internal to external relations is obviously
+limited by the modes of action of the environment on the organism,
+consequently by the structure of the organism itself. Scientific men are
+familiar with the idea that there may be forces in the environment which
+are practically inoperative on the organism, there being no
+corresponding mode of sensibility. And even if it be said that our
+present knowledge of the material world, including the doctrine of the
+conservation of energy, enables us to assert that there is no mode of
+force wholly unknown to us, it can still be contended that the
+environment may, for aught we know, be vastly more than the forces of
+which, owing to the nature of our organism, we know it to be composed.
+In short, since, on the evolution theory<span class='pagenum'><a name="Page_344" id="Page_344">[Pg 344]</a></span> viewed as a scientific
+doctrine, the real external world does not directly mirror itself in our
+minds, but only indirectly brings our perceptions and representations
+into adjustment by bringing into adjustment the nervous organism with
+which they are somehow connected, it is plain that we cannot be certain
+of adequately apprehending the external reality which is here assumed to
+exist.</p>
+
+<p>Science, then, cannot prove, but must assume the coincidence between
+permanent common intuitions and objective reality. To raise the question
+whether this coincidence is perfect or imperfect, whether all common
+intuitions known to be persistent are true or whether there are any that
+are illusory, is to pass beyond the scientific point of view to another,
+namely, the philosophic. Thus, our study of illusion naturally carries
+us on from scientific to philosophic reflection. Let me try to make this
+still more clear.</p>
+
+
+<p class='center'><i>Transition to Philosophic View.</i></p>
+
+<p>All science makes certain assumptions which it never examines. Thus, the
+physicist assumes that when we experience a sensation we are acted on by
+some pre-existing external object which is the cause, or at least one
+condition, of the sensation. While resolving the secondary qualities of
+light, sound, etc., into modes of motion, while representing the object
+very differently from the unscientific mind, he agrees with this in
+holding to the reality of something external, regarding this as
+antecedent to and therefore as independent of the particular mind which
+receives the sense-impression. Again, he assumes the uniformity<span class='pagenum'><a name="Page_345" id="Page_345">[Pg 345]</a></span> of
+nature, the universality of the causal relation, and so on.</p>
+
+<p>Similarly, the modern psychologist, when confining himself within the
+limits of positive science, and treating mind phenomenally or
+empirically, or, in other words, tracing the order of mental states in
+time and assigning their conditions, takes for granted much the same as
+physical science does. Thus, as our foregoing analysis of perception
+shows, he assumes that there is an external cause of our sensations,
+that there are material bodies in space, which act on our sense-organs
+and so serve as the condition of our sense-impressions. More than this,
+he regards, in the way that has been illustrated in this work, the
+percept itself, in so far as it is a process in time, as the normal
+result of the action of such external agents on our nerve-structures, in
+other words, as the effect of such action in the case of the healthy and
+perfect nervous organism with the average organized dispositions,
+physical and psychical; in which case he supposes the percept to
+correspond, in certain respects at least, with the external cause as
+made known by physical science. And, on the other hand, he looks on a
+false or illusory percept as arising in another way not involving, as
+its condition, the pre-existence of a corresponding material body or
+physical agent. And in this view of perception, as of other mental
+phenomena, the psychologist clearly takes for granted the principle that
+all mental events conform to the law of causation. Further, he assumes
+that the individual mind is somehow, in a way which it is not his
+province to inquire into, one and the same throughout, and so on.<span class='pagenum'><a name="Page_346" id="Page_346">[Pg 346]</a></span></p>
+
+<p>The doctrine of evolution, too, in so far as scientific&mdash;that is, aiming
+at giving an account of the historical and pre-historical developments
+of the collective mind in time&mdash;agrees with psychology in making like
+assumptions. Thus, it conceives an external agency (the environment) as
+the cause of our common sensations and perceptions. That is to say, it
+represents the external world as somehow antecedent to, and so
+apparently independent of, the perceptions which are adjusted to it. And
+all this shows that science, while removed from vulgar unenlightened
+opinion, takes sides with popular thought in assuming the truth of
+certain fundamental ideas or so-called intuitive beliefs, into the exact
+meaning of which it does not inquire.</p>
+
+<p>When the meaning of these assumptions is investigated, we pass out of
+the scientific into the philosophic domain. Philosophy has to critically
+investigate the data of popular thought and of science. It has to
+discover exactly what is implied in these fundamental principles. Then
+it has to test their value by erecting a final criterion of truth, by
+probing the structure of cognition to the bottom, and determining the
+proper organ of certain or accurate knowledge; or, to put it another
+way, it has to examine what is meant by reality, whether there is
+anything real independently of the mind, and if so, what. In doing this
+it inquires not only what common sense means by its object-world clothed
+in its variegated garment of secondary qualities, its beauty, and so on,
+but also what physical science means by its cosmic mechanism of sensible
+and extra-sensible matter in motion: whether there is any kind of
+objective reality<span class='pagenum'><a name="Page_347" id="Page_347">[Pg 347]</a></span> belonging to the latter which does not also belong to
+the former; and how the two worlds are related one to another. That is
+to say, he asks whether the bodies in space assumed to exist by the
+physicist as the antecedent conditions of particular sensations and
+percepts are independent of mind and perception generally.<a name="FNanchor_152_152" id="FNanchor_152_152"></a><a href="#Footnote_152_152" class="fnanchor">[152]</a></p>
+
+<p>In doing all this, philosophy is theoretically free to upset as much of
+popular belief of the persistent kind as it likes. Nor can science find
+fault with it so long as it keeps to its own sphere, and does not
+directly contradict any truth which science, by the methods proper to
+it, is able to establish. Thus, for example, if philosophy finds that
+there is nothing real independently of mind, science will be satisfied
+so long as it finds a meaning for its assumed entities, such as space,
+external things, and physical causes.<a name="FNanchor_153_153" id="FNanchor_153_153"></a><a href="#Footnote_153_153" class="fnanchor">[153]</a></p>
+
+<p>The student of philosophy need not be told that these imposing-looking
+problems respecting cognition, making, up what the Germans call the
+"Theory of Cognition," and the cognate problem respecting the nature of
+reality, are still a long way from being settled. To-day, as in the days
+of Plato and Aristotle, are argued, in slightly altered forms, the vexed
+questions, What is true cognition? Is it a mere efflux from<span class='pagenum'><a name="Page_348" id="Page_348">[Pg 348]</a></span> sensation,
+a passive conformity of representation to sensation (sensualism or
+empiricism)? or is it, on the other hand, a construction of active
+thought, involving certain necessary forms of intelligence (rationalism
+or intuitivism)?</p>
+
+<p>Again, how are we to shape to ourselves real objective existence? Is it
+something wholly independent of the mind (realism)? and if so, is this
+known to be what we&mdash;meaning here common people and men of science
+alike&mdash;represent it as being (natural realism), or something different
+(transfigured realism)? Or is it, on the contrary, something involving
+mind (idealism)? and if so, is it a strictly phenomenal distinction
+within our conscious experience (empirical idealism, phenomenalism), or
+one of the two poles of subject and object constituted by every act of
+thought (rational idealism)? These are some of the questions in
+philosophy which still await their final answer.</p>
+
+<p>Philosophy being thus still a question and not a solution, we need not
+here trouble ourselves about its problems further than to remark on
+their close connection with our special subject, the study of illusion.</p>
+
+<p>Our brief reference to some of the principal inquiries of philosophy
+shows that it tends to throw doubt on things which the unreflecting
+popular mind holds to be indubitable. Different schools of philosophy
+have shown themselves unequally concerned about these so-called
+intuitive certainties. In general it may be said that philosophy,
+though, as I have remarked, theoretically free to set up its own
+standard of certainty, has in practice endeavoured to give a meaning
+to,<span class='pagenum'><a name="Page_349" id="Page_349">[Pg 349]</a></span> and to find a justification for the assumptions or first principles
+of science. On the other hand, it has not hesitated, when occasion
+required, to make very light of the intuitive beliefs of the popular
+mind as interpreted by itself. Thus, rationalists of the Platonic type
+have not shrunk from pronouncing individual impressions and objects
+illusory, an assertion which certainly seems to be opposed to the
+assumptions of common sense, if not to those of science. On the other
+hand, the modern empirical or association school is quite ready to
+declare that the vulgar belief in an external world, so far as it
+represents this as independent of mind,<a name="FNanchor_154_154" id="FNanchor_154_154"></a><a href="#Footnote_154_154" class="fnanchor">[154]</a> is an illusion; that the
+so-called necessary beliefs respecting identity, uniformity, causation,
+etc., are not, strictly speaking, necessary; and so on. And in these
+ways it certainly seems to come into conflict with popular convictions,
+or intuitive certainties, as they present themselves to the unreflecting
+intelligence.</p>
+
+<p>Philosophy seems, then, to be a continuation of that process of
+detecting illusion with which science in part concerns itself. Indeed,
+it is evident that our<span class='pagenum'><a name="Page_350" id="Page_350">[Pg 350]</a></span> special study has a very close connection with
+the philosophic inquiry. What philosophy wants is something intuitively
+certain as its starting-point, some <i>point d'appui</i> for its
+construction. The errors incident to the process of reasoning do not
+greatly trouble it, since these can, in general, be guarded against by
+the rules of logic. But error in the midst of what, on the face of it,
+looks like intuitive knowledge naturally raises the question, Is there
+any kind of absolutely certain cognition, any organ for the accurate
+perception of truth? And this intimate relation between the scientific
+and the philosophic consideration of illusion is abundantly illustrated
+in the history of philosophy. The errors of sense, appearing in a region
+which to the vulgar seems so indubitable, have again and again set men
+thinking on the question, "What is the whole range of illusion? Is
+perception, as popularly understood, after all, a big hallucination? Is
+our life a dream?"<a name="FNanchor_155_155" id="FNanchor_155_155"></a><a href="#Footnote_155_155" class="fnanchor">[155]</a></p>
+
+<p>On the other hand, if our study of the wide range of illusion is fitted
+to induce that temper of mind which is said to be the beginning of
+philosophy, that attitude of universal doubt expressed by Descartes in
+his famous maxim, <i>De omnibus dubitandum</i>, a consideration of the
+process of correction is fitted to lead the mind on to the determination
+of the conditions of accurate knowledge. It is evident, indeed, that the
+very conception of an illusion implies a criterion of certainty: to call
+a thing illusory, is to judge it by reference to some accepted standard
+of truth.<span class='pagenum'><a name="Page_351" id="Page_351">[Pg 351]</a></span></p>
+
+<p>The mental processes involved in detecting, resisting, and overcoming
+illusion, are a very interesting subject for the psychologist, though we
+have not space here to investigate them fully. Turning to presentative,
+and more particularly sense-illusions, we find that the detection of an
+illusion takes place now by an appeal from one sense to another, for
+example, from sight to touch, by way of verification;<a name="FNanchor_156_156" id="FNanchor_156_156"></a><a href="#Footnote_156_156" class="fnanchor">[156]</a> now (as in
+Myer's experiment) by a reference from sense and presentation altogether
+to representation or remembered experience and a process of reasoning;
+and now, (as in the illusions of art) conversely, by a transition of
+mind from what is suggested to the actual sense-impression of the
+moment. In the sphere of memory, again, illusion is determined, as such,
+now by attending more carefully to the contents of memory, now by a
+process of reasoning from some presentative cognition. Finally, errors
+in our comprehensive general representations of things are known to be
+such partly by reasoning from other conceptions, and partly by a
+continual process of reduction of representation to presentation, the
+general to the particular. I may add that the correction of illusion by
+an act of reflection and reasoning, which brings the part into
+consistent relation with the whole of experience, includes throughout
+the comparison of the individual with the collective or social
+experience.<a name="FNanchor_157_157" id="FNanchor_157_157"></a><a href="#Footnote_157_157" class="fnanchor">[157]</a><span class='pagenum'><a name="Page_352" id="Page_352">[Pg 352]</a></span></p>
+
+<p>We may, perhaps, roughly summarize these operations by saying that they
+consist in the control of the lower automatic processes (association or
+suggestion) by the higher activities of conscious will. This activity of
+will takes the form now of an effort of attention to what is directly
+present to the mind (sense-impression, internal feeling, mnemonic image,
+etc.), now of conscious reflection, judgment, and reasoning, by which
+the error is brought into relation to our experience as a whole,
+individual and collective.</p>
+
+<p>It is for the philosopher to investigate the inmost nature of these
+operations as they exhibit themselves in our every-day individual
+experience, and in the large intellectual movements of history. In no
+better way can he arrive at what common sense and science regard as
+certain cognition, at the kinds of knowledge on which they are wont to
+rely most unhesitatingly.</p>
+
+<p>There is one other relation of our subject to philosophic problems which
+I have purposely left for final consideration. Our study has consisted
+mainly in the psychological analysis of illusions supposed to be known
+or capable of being known as such. Now, the modern association school
+professes to be able to resolve some of the so-called intuitions of
+common sense into elements exactly similar to those into which we have
+here been resolving what are acknowledged by all as illusions. This fact
+would seem to point to a close connection between the scientific study
+of illusion and the particular view of these fundamental intuitions
+taken by one philosophic school. In order to see whether there is really
+this connection, we must reflect<span class='pagenum'><a name="Page_353" id="Page_353">[Pg 353]</a></span> a little further on the nature of the
+method which we have been pursuing.</p>
+
+<p>I have already had occasion to rise the expression "scientific
+psychology," or psychology as a positive science, and the meaning of
+this expression must now be more carefully considered. As a positive
+science, psychology is limited to the function of analyzing mental
+states, and of tracing their origin in previous and more simple mental
+states. It has, strictly speaking, nothing to do with the question of
+the legitimacy or validity of any mental act.</p>
+
+<p>Take a percept, for example. Psychology can trace its parentage in
+sensation, the mode in which it has come by its contents in the laws of
+association. But by common consent, a percept implies a presentative
+apprehension of an object now present to sense. Is this valid or
+illusory? This question psychology, as science, does not attempt to
+answer. It would not, I conceive, answer it even if it were able to make
+out that the whole mental content in the percept can be traced back to
+elementary sensations and their combinations. For the fact that in the
+chemistry of mind elements may combine in perfectly new forms does not
+disprove that the forms thus arising, whether sentiments or
+quasi-cognitions, are invalid. Much less can psychology dispute the
+validity of a percept if it cannot be sure that the mind adds nothing to
+sensation and its grouping; that in the genesis of the perceptive state,
+with its intuition of something external and now present as object,
+nothing like a form of intelligence is superimposed on the elements of
+sensation, giving to the result of their coalescence the particular
+unity<span class='pagenum'><a name="Page_354" id="Page_354">[Pg 354]</a></span> which we find. Whether psychology as a positive science can ever
+be sure of this: whether, that is to say, it can answer the question,
+"How do we come by the idea of object?" without assuming some particular
+philosophic or extra-scientific theory respecting the ultimate nature of
+mind, is a point which I purposely leave open.</p>
+
+<p>I would contend, then, that the psychologist, in tracing the genesis of
+the percept out of previous mental experiences, no more settles the
+question, What is the object of perception? than the physicist settles
+it in referring the sense-impression (and so the percept) to a present
+material agent as its condition.</p>
+
+<p>The same applies to our idea of self. I may discover the concrete
+experiences which supply the filling in of the idea, and yet not settle
+the question, Does intelligence add anything in the construction of the
+form of this idea? and still less settle the question whether there is
+any real unity answering to the idea.</p>
+
+<p>If this is a correct distinction, if psychology, as science, does not
+determine questions of validity or objective meaning but only of
+genesis, if it looks at mental states in relation only to their temporal
+and causal concomitants and not to their objects, it must follow that
+our preceding analysis of illusion involves no particular philosophic
+theory as to the nature of intelligence, but, so far as accurate,
+consists of scientific facts which all philosophic theories of
+intelligence must alike be prepared to accept. And I have little doubt
+that each of the two great opposed doctrines, the intuitive and the
+associational, would claim to be<span class='pagenum'><a name="Page_355" id="Page_355">[Pg 355]</a></span> in a position to take up these facts
+into its particular theory, and to view them in its own way.</p>
+
+<p>But in addition to this scientific psychology, there is another
+so-called psychology, which is, strictly speaking, philosophic. This, I
+need hardly say, is the association philosophy. It proceeds by analyzing
+certain cognitions and sentiments into their elements, and straightway
+declaring that they mean nothing more than these. That is to say, the
+associationist passes from genesis to validity, from the history of a
+conscious state to its objective meaning. Thus, from showing that an
+intuitive belief, say that in causation, is not original (in the
+individual or at least in the race), it goes on to assert that it is not
+a valid immediate cognition at all. Now, I am not concerned here to
+inquire into the logical value of this transition, but simply to point
+out that it is extra-scientific and distinctly philosophic. If logically
+justifiable, it is so because of some plainly <i>philosophic</i> assumption,
+as that made by Hume, namely, that all ideas not derived from
+impressions are to this extent fictitious or illusory.</p>
+
+<p>And now we are in a position to understand the bearing of our scientific
+analysis of acknowledged illusions on the associationist's treatment of
+the alleged illusions of common sense. There is no doubt, I think, that
+some of the so-called intuitions of common sense have points of analogy
+to acknowledged illusions. For example, the conviction in the act of
+perception that something external to the mind and independent of it
+exists, has a certain superficial resemblance to an hallucination of
+sense; and moreover, the associationist seeks to explain it by means of
+these very processes which<span class='pagenum'><a name="Page_356" id="Page_356">[Pg 356]</a></span> underlie what is recognized by all as
+sense-illusion.<a name="FNanchor_158_158" id="FNanchor_158_158"></a><a href="#Footnote_158_158" class="fnanchor">[158]</a> Again, it may be said that our notions of force and
+of a causal nexus in the physical world imply the idea of conscious
+energy as known through our muscular sensations, and so have a
+suspicious resemblance to those anthropomorphic illusions of which I
+have spoken under Illusions of Insight. Once more, the consciousness of
+freedom may, as I have suggested, be viewed as analogous in its form and
+its mode of origin to illusions of introspection. As a last example, it
+may be said that the mind's certain conviction of the innateness of some
+of its ideas resembles those illusions of memory which arise through an
+inability to think ourselves back into a remote past having a type of
+consciousness widely unlike that of the present.</p>
+
+<p>But now, mark the difference. In our scientific analysis of popularly
+known illusions, we had something by which to determine the illusory
+character of the presentation or belief. We had a popularly or
+scientifically accepted standard of certainty, by a reference to which
+we might test the particular <i>soi-disant</i> cognition. But in the case of
+these fundamental beliefs we have no such criterion, except we adopt
+some particular philosophic theory, say that of the associationist
+himself. Hence this similarity in structure and origin cannot in itself
+be said to amount to a proof of equality of logical or objective value.
+Here again it must be remarked that origin, does not carry validity or
+invalidity with it.<a name="FNanchor_159_159" id="FNanchor_159_159"></a><a href="#Footnote_159_159" class="fnanchor">[159]</a><span class='pagenum'><a name="Page_357" id="Page_357">[Pg 357]</a></span></p>
+
+<p>We thus come back to our starting-point. While there are close
+relations, psychological and logical, between the scientific study of
+the ascertained facts of illusion and the philosophic determination of
+what is illusory in knowledge as a whole, the two domains must be
+clearly distinguished. On purely scientific ground we cannot answer the
+question, "How far does illusion extend?" The solution of this question
+must be handed over to the philosopher, as one aspect of his problem of
+cognition.</p>
+
+<p>One or two remarks may, perhaps, be hazarded in concluding this account
+of the relation of the scientific to the philosophic problem of
+illusion. Science, as we have seen, takes its stand on a stable
+consensus, a body of commonly accepted belief. And this being so, it
+would seem to follow, that so far as she is allowed to interest herself
+in philosophic questions, she will naturally be disposed to ask, What
+beliefs are shared in by all minds, so far as normal and developed? In
+other words, she will be inclined to look at universality<span class='pagenum'><a name="Page_358" id="Page_358">[Pg 358]</a></span> as the main
+thing to be determined in the region of philosophic inquiry. The
+metaphysical sceptic, fond of daring exploits, may break up as many
+accepted ideas as he likes into illusory <i>d&eacute;bris</i>, provided only he has
+some bit of reality left to take his stand on. Meanwhile, the scientific
+mind, here agreeing with the practical mind, will ask, "Will the beliefs
+thus said to be capable of being shown to be illusory ever cease to
+exercise their hold on men's minds, including that of the iconoclast
+himself? Is the mode of demonstration of such a kind as to be likely
+ever to materially weaken the common-sense 'intuition'?"</p>
+
+<p>This question would seem to be most directly answerable by an appeal to
+individual testimony. Viewed in this light, it is a question for the
+present, for some few already allege that in their case philosophic
+reasonings exercise an appreciable effect on these beliefs. And so far
+as this is so, the man of scientific temper will feel that there is a
+question for him.</p>
+
+<p>It is evident, however, that the question of the persistence of these
+fundamental beliefs is much more one for the future than for the
+present. The correction of a clearly detected illusion is, as I have
+more than once remarked, a slow process. An illusion such as the
+apparent movement of the sun will persist as a partially developed error
+long after it has been convicted. And it may be that the fundamental
+beliefs here referred to, even if presumably illusory, are destined to
+exercise their spell for long ages yet.</p>
+
+<p>Whether this will be the case or not, whether these intuitive beliefs
+are destined slowly to decay and be dissolved as time rolls on, or
+whether they will retain<span class='pagenum'><a name="Page_359" id="Page_359">[Pg 359]</a></span> an eternal youth, is a question which we of
+to-day seem, on a first view of the matter, to have no way of answering
+which does not assume the very point in question&mdash;the truth or falsity
+of the belief. This much may, however, be said. The associationist who
+resolves these erroneous intuitions into the play of association, admits
+that the forces at work generating and consolidating the illusory belief
+are constant and permanent forces, and such as are not likely to be less
+effective in the future than they have been in the past. Thus, he
+teaches that the intuition of the single object in the act of perception
+owes its strength to "inseparable association," according to which law
+the ideas of the separate "possibilities of sensation," which are all we
+know of the object, coalesce in the shape of an idea of a single uniting
+substance. He adds, perhaps, that heredity has tended, and will still
+tend, to fix the habit of thus transforming an actual multiplicity into
+an imaginary unity. And in thus arguing, he is allowing that the
+illusion is one which, to say the least of it, it will always be
+exceedingly difficult for reason to dislodge.</p>
+
+<p>In view of this uncertainty, and of the possibility, if not the
+probability, of these beliefs remaining as they have remained, at least
+approximately universal, the man of science will probably be disposed to
+hold himself indifferently to the question. He will be inclined to say,
+"What does it matter whether you call such an apparently permanent
+belief the correlative of a reality or an illusion? Does it make any
+practical difference whether a universal 'intuition,' of which we cannot
+rid ourselves, be described<span class='pagenum'><a name="Page_360" id="Page_360">[Pg 360]</a></span> as a uniformly recurring fiction of the
+imagination, or an integral constitutive factor of intelligence? And, in
+considering the historical aspect of the question, does it not come to
+much the same thing whether such permanent mental products be spoken of
+as the attenuated forms or ghostly survivals of more substantial
+primitive illusions (for example, anthropomorphic representations of
+material objects, 'animistic' representations of mind and personality),
+or as the slowly perfected results of intellectual evolution?"</p>
+
+<p>This attitude of the scientific mind towards philosophic problems will
+be confirmed when it is seen that those who seek to resolve stable
+common convictions into illusions are forced, by their very mode of
+demonstration, to allow these intuitions a measure of validity. Thus,
+the ideas of the unity and externality attributed to the object in the
+act of perception are said by the associationist to answer to a matter
+of fact, namely, the permanent coexistence of certain possibilities of
+sensation, and the dependence of the single sensations of the individual
+on the presence of the most permanent of these possibilities, namely,
+those of the active or muscular and passive sensations of touch, which
+are, moreover, by far the most constant for all minds. Similarly, the
+idea of a necessary connection between cause and effect, even if
+illusory in so far as it expresses an <i>objective</i> necessity, is allowed
+to be true as an expression of that uniformity of our experience which
+all scientific progress tends to illustrate more and more distinctly.
+And even the idea of a permanent self, as distinct from particular
+fugitive feelings, is admitted by the associationist to be correct in so
+far as it ex<span class='pagenum'><a name="Page_361" id="Page_361">[Pg 361]</a></span>presses the fact that mind is "a series of feelings which
+is aware of itself as past and future." In short, these "illusory
+intuitions," by the showing of those who affirm them to be illusory, are
+by no means hallucinations having no real object as their correlative,
+but merely illusions in the narrow sense, and illusions, moreover, in
+which the ratio of truth to error seems to be a large one.</p>
+
+<p>It would thus appear that philosophy tends, after all, to unsettle what
+appear to be permanent convictions of the common mind and the
+presuppositions of science much less than is sometimes imagined. Our
+intuitions of external realities, our indestructible belief in the
+uniformity of nature, in the nexus of cause and effect, and so on, are,
+by the admission of all philosophers, at least partially and
+<i>relatively</i> true; that is to say, true in relation to certain features
+of our common experience. At the worst, they can only be called illusory
+as slightly misrepresenting the exact results of this experience. And
+even so, the misrepresentation must, by the very nature of the case, be
+practically insignificant. And so in full view of the subtleties of
+philosophic speculation, the man of science may still feel justified in
+regarding his standard of truth, a stable consensus of belief, as above
+suspicion.<span class='pagenum'><a name="Page_363" id="Page_363">[Pg 363]</a></span><span class='pagenum'><a name="Page_362" id="Page_362">[Pg 362]</a></span></p>
+
+
+
+<hr style="width: 65%;" />
+
+<div class="trans-note">
+        Transcribers note: In the original some footnotes read 'note[1]and
+note[2]'. They have been renumbered to allow readers to refer directly
+to them.
+    </div>
+
+<h2>INDEX.</h2>
+
+
+<p>
+<span style="margin-left: 1em;">A.</span><br />
+<br />
+<span style="margin-left: 1em;">Abercrombie, Dr. J, <a href='#Page_141'>141</a>, note<a href="#Footnote_82_82" class="fnanchor">[82]</a>, <a href='#Page_278'>278</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Abnormal life, relation of,</span><br />
+<span style="margin-left: 2em;">to normal, <a href='#Page_1'>1</a>, <a href='#Page_120'>120</a>, <a href='#Page_121'>121</a>, <a href='#Page_124'>124</a>, <a href='#Page_182'>182</a>, <a href='#Page_277'>277</a>, <a href='#Page_284'>284</a>, note<a href="#Footnote_132_132" class="fnanchor">[132]</a>, <a href='#Page_336'>336</a>;</span><br />
+<span style="margin-left: 2em;">effects of amputation, <a href='#Page_62'>62</a>;</span><br />
+<span style="margin-left: 2em;">modification of sensibility in, <a href='#Page_65'>65</a>;</span><br />
+<span style="margin-left: 2em;">gross sense-illusions of, <a href='#Page_111'>111</a>, hallucinations of, <a href='#Page_118'>118</a>;</span><br />
+<span style="margin-left: 2em;">sense of personal identity in, <a href='#Page_289'>289</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Active, stage in perception, <a href='#Page_27'>27</a>;</span><br />
+<span style="margin-left: 2em;">illusion distinguished from passive, <a href='#Page_45'>45</a>, <a href='#Page_332'>332-334</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Actor. <i>See</i> Theatre.</span><br />
+<br />
+<span style="margin-left: 1em;">Adaptation, illusion as want of, <a href='#Page_124'>124</a>, <a href='#Page_188'>188</a>, <a href='#Page_339'>339</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">&AElig;sthetic intuition, <a href='#Page_213'>213</a>;</span><br />
+<span style="margin-left: 2em;">illusions of, <a href='#Page_214'>214</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">After-dreams, <a href='#Page_144'>144</a>, <a href='#Page_183'>183</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">After-sensation, after-impression, <a href='#Page_55'>55</a>, <a href='#Page_115'>115</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">An&aelig;sthesia, <a href='#Page_65'>65</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Ancestral experience, results of, <a href='#Page_281'>281</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Animals, recognition of portraits by, <a href='#Page_105'>105</a>;</span><br />
+<span style="margin-left: 2em;">expectation of, <a href='#Page_298'>298</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Anthropomorphism, <a href='#Page_225'>225</a>, <a href='#Page_360'>360</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Anticipation. <i>See</i> Expectation.</span><br />
+<br />
+<span style="margin-left: 1em;">Apparitions. <i>See</i> Hallucination.</span><br />
+<br />
+<span style="margin-left: 1em;">Aristotle, <a href='#Page_130'>130</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Art, illusions of, <a href='#Page_77'>77</a>, <a href='#Page_104'>104</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Artemidoros, <a href='#Page_129'>129</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Association, laws of, in perception, <a href='#Page_22'>22</a>;</span><br />
+<span style="margin-left: 2em;">in dreams, <a href='#Page_153'>153</a>, <a href='#Page_156'>156</a>;</span><br />
+<span style="margin-left: 2em;">link of resemblance in dreams, <a href='#Page_159'>159</a>;</span><br />
+<span style="margin-left: 2em;">associative dispositions in dreams, <a href='#Page_169'>169</a>;</span><br />
+<span style="margin-left: 2em;">effect of, in insight, <a href='#Page_221'>221</a>;</span><br />
+<span style="margin-left: 2em;">inseparable, <a href='#Page_359'>359</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Associationist, views of, <a href='#Page_349'>349</a>, <a href='#Page_352'>352</a>, <a href='#Page_355'>355</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Attention, involved in perception <a href='#Page_21'>21</a>;</span><br />
+<span style="margin-left: 2em;">absence of, in sense-illusion, <a href='#Page_39'>39</a>, <a href='#Page_87'>87</a>;</span><br />
+<span style="margin-left: 2em;">relation of, to recognition of objects, <a href='#Page_90'>90</a>;</span><br />
+<span style="margin-left: 2em;">expectant, <a href='#Page_93'>93</a>;</span><br />
+<span style="margin-left: 2em;">attitude of, in dreaming, <a href='#Page_137'>137</a>, <a href='#Page_172'>172</a>;</span><br />
+<span style="margin-left: 2em;">to internal mental states, <a href='#Page_194'>194</a>;</span><br />
+<span style="margin-left: 2em;">absence of, in errors of insight, <a href='#Page_228'>228</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Authority, influence of, in introspection, <a href='#Page_210'>210</a>;</span><br />
+<span style="margin-left: 2em;">in belief, <a href='#Page_325'>325</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Autobiography, errors connected with, <a href='#Page_276'>276</a>, <a href='#Page_280'>280</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Automatic activity of centres, in hallucinations, <a href='#Page_113'>113</a>;</span><br />
+<span style="margin-left: 2em;">in dreams, <a href='#Page_136'>136</a>, <a href='#Page_151'>151</a>;</span><br />
+<span style="margin-left: 2em;">automatic intellectual processes, <a href='#Page_300'>300</a>, <a href='#Page_335'>335</a>, <a href='#Page_352'>352</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">B.</span><br />
+<br />
+<span style="margin-left: 1em;">Baillarger, J., <a href='#Page_13'>13</a>, note <a href="#Footnote_1_1" class="fnanchor">[1]</a>, <a href='#Page_113'>113</a>, note<a href="#Footnote_57_57" class="fnanchor">[57]</a>, <a href='#Page_119'>119</a>,</span><br />
+<span style="margin-left: 2em;">notes<a href="#Footnote_64_64" class="fnanchor">[64]</a> and <a href="#Footnote_65_65" class="fnanchor">[65]</a>], <a href='#Page_120'>120</a>, note<a href="#Footnote_66_66" class="fnanchor">[66]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Bain, Dr. A., <a href='#Page_32'>32</a>, note<a href="#Footnote_12_12" class="fnanchor">[12]</a>, <a href='#Page_117'>117</a>, note<a href="#Footnote_60_60" class="fnanchor">[60]</a>, <a href='#Page_190'>190</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Beattie, J., <a href='#Page_141'>141</a>, note<a href="#Footnote_82_82" class="fnanchor">[82]</a>].</span><br />
+<br />
+<span style="margin-left: 1em;">Beauty, sentiment of, <a href='#Page_206'>206</a>, <a href='#Page_213'>213</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Belief, immediate, <a href='#Page_14'>14</a>, <a href='#Page_15'>15</a>, <a href='#Page_294'>294</a>;</span><br />
+<span class='pagenum'><a name="Page_364" id="Page_364">[Pg 364]</a></span><span style="margin-left: 2em;">simple and compound, <a href='#Page_296'>296</a>;</span><br />
+<span style="margin-left: 2em;">illusory forms of, <a href='#Page_297'>297</a>;</span><br />
+<span style="margin-left: 2em;">simple expectation, <a href='#Page_297'>297</a>;</span><br />
+<span style="margin-left: 2em;">expectation, of extra-personal experiences, <a href='#Page_307'>307</a>;</span><br />
+<span style="margin-left: 2em;">retrospective, <a href='#Page_309'>309</a>;</span><br />
+<span style="margin-left: 2em;">in persistent objects and persons, <a href='#Page_312'>312</a>;</span><br />
+<span style="margin-left: 2em;">self-esteem, <a href='#Page_315'>315</a>;</span><br />
+<span style="margin-left: 2em;">representation of classes of things, <a href='#Page_322'>322</a>;</span><br />
+<span style="margin-left: 2em;">representations of mankind, <a href='#Page_322'>322</a>;</span><br />
+<span style="margin-left: 2em;">representation of life and the world as a whole, <a href='#Page_322'>322</a>;</span><br />
+<span style="margin-left: 2em;">as predisposition to error, <a href='#Page_324'>324</a>;</span><br />
+<span style="margin-left: 2em;">amount of divergence in, <a href='#Page_325'>325</a>;</span><br />
+<span style="margin-left: 2em;">tendency towards convergence in, <a href='#Page_326'>326</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Beneficial, correct knowledge as, <a href='#Page_340'>340</a>;</span><br />
+<span style="margin-left: 2em;">illusion as, <a href='#Page_342'>342</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Berkeley, Bishop, <a href='#Page_218'>218</a>, <a href='#Page_349'>349</a>, note<a href="#Footnote_154_154" class="fnanchor">[154]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Binet, A., <a href='#Page_53'>53</a>, note<a href="#Footnote_20_20" class="fnanchor">[20]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Boismont, Brierre de, <a href='#Page_11'>11</a>, note<a href="#Footnote_1_1" class="fnanchor">[1]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">B&ouml;rner, J., <a href='#Page_146'>146</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Braid, James, <a href='#Page_186'>186</a>, <a href='#Page_187'>187</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Brewster, Sir D., <a href='#Page_42'>42</a>, <a href='#Page_73'>73</a>, <a href='#Page_81'>81</a>, <a href='#Page_116'>116</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Br&uuml;cke, E., <a href='#Page_77'>77</a>, note<a href="#Footnote_38_38" class="fnanchor">[38]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Byron, Lord, <a href='#Page_116'>116</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">C.</span><br />
+<br />
+<span style="margin-left: 1em;">Carpenter, Dr. W.B., <a href='#Page_32'>32</a>, note<a href="#Footnote_12_12" class="fnanchor">[12]</a>, <a href='#Page_108'>108</a>, <a href='#Page_110'>110</a>, note<a href="#Footnote_56_56" class="fnanchor">[56]</a>, <a href='#Page_186'>186</a>, <a href='#Page_231'>231</a>,</span><br />
+<span style="margin-left: 2em;">note<a href="#Footnote_111_111" class="fnanchor">[111]</a>, <a href='#Page_265'>265</a>, note<a href="#Footnote_125_125" class="fnanchor">[125]</a>, <a href='#Page_276'>276</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Castle-building, as illusory perception, <a href='#Page_3'>3</a>, <a href='#Page_99'>99</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Cause, idea of, in science, <a href='#Page_344'>344</a>;</span><br />
+<span style="margin-left: 2em;">reality of relation of, <a href='#Page_347'>347</a>, <a href='#Page_349'>349</a>, <a href='#Page_356'>356</a>, <a href='#Page_360'>360</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Change, a condition of conscious life, <a href='#Page_252'>252</a>, <a href='#Page_287'>287</a>, note<a href="#Footnote_133_133" class="fnanchor">[133]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Childhood, our recollections of, <a href='#Page_263'>263</a>, <a href='#Page_269'>269</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Children, curiosity of, <a href='#Page_175'>175</a>, <a href='#Page_180'>180</a>;</span><br />
+<span style="margin-left: 2em;">estimate of time by, <a href='#Page_256'>256</a>;</span><br />
+<span style="margin-left: 2em;">confusion of dream and waking life by, <a href='#Page_276'>276</a>;</span><br />
+<span style="margin-left: 2em;">imagination of, <a href='#Page_279'>279</a>;</span><br />
+<span style="margin-left: 2em;">self-assertion of, <a href='#Page_319'>319</a>;</span><br />
+<span style="margin-left: 2em;">intellectual condition of, <a href='#Page_357'>357</a>, note<a href="#Footnote_159_159" class="fnanchor">[159]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Clarke, Dr. E.H., <a href='#Page_117'>117</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Classification, in recognition of sensation, <a href='#Page_21'>21</a>;</span><br />
+<span style="margin-left: 2em;">in recognition, of object, <a href='#Page_24'>24</a>;</span><br />
+<span style="margin-left: 2em;">in introspective recognition, <a href='#Page_193'>193</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Clifford, Professor W.K., <a href='#Page_56'>56</a>, note<a href="#Footnote_24_24" class="fnanchor">[24]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Coalescence, of sensations, <a href='#Page_43'>43</a>, <a href='#Page_52'>52</a>;</span><br />
+<span style="margin-left: 2em;">of dream-images, <a href='#Page_162'>162</a>;</span><br />
+<span style="margin-left: 2em;">of internal feelings, <a href='#Page_196'>196</a>;</span><br />
+<span style="margin-left: 2em;">of mnemonic images, <a href='#Page_265'>265</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">C&oelig;n&aelig;sthesis, <a href='#Page_41'>41</a>, <a href='#Page_99'>99</a>, <a href='#Page_145'>145</a>, <a href='#Page_286'>286</a>, <a href='#Page_288'>288</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Cognition, immediate or intuitive, <a href='#Page_5'>5</a>, <a href='#Page_14'>14-16</a>, <a href='#Page_294'>294</a>;</span><br />
+<span style="margin-left: 2em;">presentative and representative, <a href='#Page_9'>9</a>, <a href='#Page_13'>13</a>, <a href='#Page_217'>217</a>, <a href='#Page_330'>330</a>;</span><br />
+<span style="margin-left: 2em;">nature of, in dreams, <a href='#Page_168'>168</a>, <a href='#Page_172'>172</a>;</span><br />
+<span style="margin-left: 2em;">nature of, generally, <a href='#Page_295'>295</a>, <a href='#Page_331'>331</a>;</span><br />
+<span style="margin-left: 2em;">philosophic problems of, <a href='#Page_346'>346</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Colour, external reality of, <a href='#Page_8'>8</a>, <a href='#Page_37'>37</a>;</span><br />
+<span style="margin-left: 2em;">illusory perception of, <a href='#Page_37'>37</a>, <a href='#Page_88'>88</a>;</span><br />
+<span style="margin-left: 2em;">subjective complementary colours (colour-contrast), <a href='#Page_67'>67</a>, <a href='#Page_83'>83</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Coloured media, objects seen through, <a href='#Page_82'>82</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Common cognition, and truth, <a href='#Page_337'>337</a>;</span><br />
+<span style="margin-left: 2em;">genesis and validity of, <a href='#Page_353'>353</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Common experience distinguished from</span><br />
+<span style="margin-left: 2em;">individual, <a href='#Page_26'>26</a>, <a href='#Page_27'>27</a>, <a href='#Page_137'>137</a>, <a href='#Page_209'>209</a>, <a href='#Page_214'>214</a>, <a href='#Page_336'>336</a>, <a href='#Page_351'>351</a>;</span><br />
+<span style="margin-left: 2em;">illusion as, <a href='#Page_47'>47</a>,<a href='#Page_325'>325</a>, <a href='#Page_337'>337</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Common sense, intuitions of, <a href='#Page_346'>346</a>, <a href='#Page_349'>349</a>, <a href='#Page_352'>352</a>, <a href='#Page_357'>357</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Complementary colours, <a href='#Page_67'>67</a>, <a href='#Page_83'>83</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Concave, apparent conversion of, into convex, <a href='#Page_84'>84</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Conjuror, tricks of, <a href='#Page_56'>56</a>, <a href='#Page_106'>106</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Consciousness, veracity of, <a href='#Page_192'>192</a>, <a href='#Page_205'>205</a>;</span><br />
+<span style="margin-left: 2em;">inspection of phenomena of, <a href='#Page_196'>196</a>;</span><br />
+<span style="margin-left: 2em;">of self, <a href='#Page_283'>283</a>, <a href='#Page_285'>285</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Consensus, the standard of truth, <a href='#Page_7'>7</a>, <a href='#Page_8'>8</a>, <a href='#Page_211'>211</a>, <a href='#Page_325'>325</a>, <a href='#Page_338'>338</a>, <a href='#Page_357'>357</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Conservation of energy, <a href='#Page_343'>343</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Construction, rational, in dreams, <a href='#Page_170'>170</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Continuum, the perception of the world as, <a href='#Page_52'>52</a>, <a href='#Page_56'>56</a>, note<a href="#Footnote_24_24" class="fnanchor">[24]</a> .</span><br />
+<br />
+<span style="margin-left: 1em;">Correction of illusion, in sense-illusion, <a href='#Page_38'>38</a>, <a href='#Page_124'>124</a>, <a href='#Page_137'>137</a>;</span><br />
+<span style="margin-left: 2em;">dreams, <a href='#Page_182'>182</a>;</span><br />
+<span style="margin-left: 2em;">introspection, <a href='#Page_210'>210</a>;</span><br />
+<span style="margin-left: 2em;">insight, <a href='#Page_229'>229</a>;</span><br />
+<span style="margin-left: 2em;">memory, <a href='#Page_291'>291</a>;</span><br />
+<span class='pagenum'><a name="Page_365" id="Page_365">[Pg 365]</a></span><span style="margin-left: 2em;">historical correction <a href='#Page_338'>338</a>;</span><br />
+<span style="margin-left: 2em;">intellectual processes involved in, <a href='#Page_351'>351</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Criterion of illusion, <a href='#Page_337'>337</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Cudworth, R., <a href='#Page_161'>161</a></span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">D.</span><br />
+<br />
+<span style="margin-left: 1em;">Deception of the senses, <a href='#Page_19'>19</a>;</span><br />
+<span style="margin-left: 2em;">self-deception, <a href='#Page_200'>200</a>;</span><br />
+<span style="margin-left: 2em;">conscious deception of others, <a href='#Page_222'>222</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Delb&oelig;uf, J., <a href='#Page_175'>175</a>, note<a href="#Footnote_97_97" class="fnanchor">[97]</a>. <a href='#Page_235'>235</a>, note<a href="#Footnote_113_113" class="fnanchor">[113]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Delirium tremens</i>, <a href='#Page_118'>118</a>, note<a href="#Footnote_62_62" class="fnanchor">[62]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Democritus, <a href='#Page_130'>130</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">De Quincey, <a href='#Page_253'>253</a>, <a href='#Page_280'>280</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Descartes, R., <a href='#Page_116'>116</a>, <a href='#Page_350'>350</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Dickens, Charles, <a href='#Page_277'>277</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Direction, illusory sense of, in vision, <a href='#Page_66'>66</a>, <a href='#Page_71'>71</a>, <a href='#Page_73'>73</a>;</span><br />
+<span style="margin-left: 1.5em;">in hearing, <a href='#Page_72'>72</a>, <a href='#Page_75'>75</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Disease. <i>See</i> Abnormal life.</span><br />
+<br />
+<span style="margin-left: 1em;">Dissolution. <i>See</i> Evolution.</span><br />
+<br />
+<span style="margin-left: 1em;">Doubt, starting-point in philosophy, <a href='#Page_350'>350</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Dreams, relation of, to illusions of sense, <a href='#Page_18'>18</a>, <a href='#Page_130'>130</a>;</span><br />
+<span style="margin-left: 2em;">and waking experience, <a href='#Page_127'>127</a>;</span><br />
+<span style="margin-left: 2em;">theories of, <a href='#Page_128'>128</a>;</span><br />
+<span style="margin-left: 2em;">physiology of, <a href='#Page_131'>131</a>;</span><br />
+<span style="margin-left: 2em;">extent of, in sleep, <a href='#Page_132'>132</a>;</span><br />
+<span style="margin-left: 2em;">psychological conditions of, <a href='#Page_136'>136</a>;</span><br />
+<span style="margin-left: 2em;">excitants of, <a href='#Page_139'>139</a>, <a href='#Page_143'>143</a>;</span><br />
+<span style="margin-left: 2em;">exaggeration in, <a href='#Page_147'>147</a>;</span><br />
+<span style="margin-left: 2em;">symbolism of, <a href='#Page_149'>149</a>;</span><br />
+<span style="margin-left: 2em;">as results of automatic activity of centres, <a href='#Page_151'>151</a>;</span><br />
+<span style="margin-left: 2em;">as results of association, <a href='#Page_153'>153</a>;</span><br />
+<span style="margin-left: 2em;">structure of, <a href='#Page_156'>156</a>;</span><br />
+<span style="margin-left: 2em;">incoherent, <a href='#Page_156'>156</a>;</span><br />
+<span style="margin-left: 2em;">coherent, <a href='#Page_161'>161</a>;</span><br />
+<span style="margin-left: 2em;">action of feeling in, <a href='#Page_164'>164</a>;</span><br />
+<span style="margin-left: 2em;">play of associative dispositions in, <a href='#Page_168'>168</a>;</span><br />
+<span style="margin-left: 2em;">co-operation of attention and intelligence in, <a href='#Page_172'>172</a>;</span><br />
+<span style="margin-left: 2em;">limits of intelligence in, <a href='#Page_180'>180</a>;</span><br />
+<span style="margin-left: 2em;">after-dreams, <a href='#Page_183'>183</a>, <a href='#Page_274'>274</a>;</span><br />
+<span style="margin-left: 2em;">relation of, to hypnotic condition, <a href='#Page_185'>185</a>;</span><br />
+<span style="margin-left: 2em;">experience of, in relation to errors of memory, <a href='#Page_273'>273</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">E.</span><br />
+<br />
+<span style="margin-left: 1em;">Eccentricity, law of, <a href='#Page_59'>59</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Ego. <i>See</i> Self.</span><br />
+<br />
+<span style="margin-left: 1em;">Emotion, and illusion of perception, <a href='#Page_103'>103</a>;</span><br />
+<span style="margin-left: 2em;">and hallucination, <a href='#Page_115'>115</a>;</span><br />
+<span style="margin-left: 2em;">and bodily sensations, <a href='#Page_150'>150</a>;</span><br />
+<span style="margin-left: 2em;">control of dreams by, <a href='#Page_164'>164</a>;</span><br />
+<span style="margin-left: 2em;">introspection of, <a href='#Page_199'>199</a>;</span><br />
+<span style="margin-left: 2em;">and illusion of introspection, <a href='#Page_203'>203</a>;</span><br />
+<span style="margin-left: 2em;">and &aelig;sthetic intuition, <a href='#Page_213'>213</a>;</span><br />
+<span style="margin-left: 2em;">and illusion of memory, <a href='#Page_270'>270</a>;</span><br />
+<span style="margin-left: 2em;">and illusion of belief, <a href='#Page_306'>306</a>, <a href='#Page_324'>324</a>;</span><br />
+<span style="margin-left: 2em;">and cognition generally, <a href='#Page_357'>357</a>, note<a href="#Footnote_159_159" class="fnanchor">[159]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Empiricism, philosophic, <a href='#Page_348'>348</a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Ennui</i>, and sense of time, <a href='#Page_250'>250</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Environment, sources of sense-illusion in, <a href='#Page_47'>47</a>, <a href='#Page_48'>48</a>, <a href='#Page_70'>70</a>;</span><br />
+<span style="margin-left: 2em;">view of, in mental disease, <a href='#Page_290'>290</a>, <a href='#Page_326'>326</a>;</span><br />
+<span style="margin-left: 2em;">view of, in normal life, <a href='#Page_323'>323</a>;</span><br />
+<span style="margin-left: 2em;">action of, in assimilating belief, <a href='#Page_339'>339</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Error, immediate and mediate, <a href='#Page_6'>6</a>, <a href='#Page_334'>334</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Esquirol, J.E.D., <a href='#Page_12'>12</a>, note<a href="#Footnote_2_2" class="fnanchor">[2]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Evolution, relation of, to dissolution, <a href='#Page_122'>122</a>;</span><br />
+<span style="margin-left: 2em;">of power of introspection, <a href='#Page_209'>209</a>;</span><br />
+<span style="margin-left: 2em;">of power of insight, <a href='#Page_230'>230</a>;</span><br />
+<span style="margin-left: 2em;">and self-assertion, <a href='#Page_320'>320</a>;</span><br />
+<span style="margin-left: 2em;">evolutionist's view of error, <a href='#Page_339'>339</a>;</span><br />
+<span style="margin-left: 2em;">doctrine of, as science, <a href='#Page_346'>346</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Exaggeration, in interpretation of sensations, <a href='#Page_65'>65</a>;</span><br />
+<span style="margin-left: 2em;">in dream-interpretation, <a href='#Page_147'>147</a>;</span><br />
+<span style="margin-left: 2em;">in memory, <a href='#Page_269'>269</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Expectation, preliminary to perception, <a href='#Page_30'>30</a>;</span><br />
+<span style="margin-left: 2em;">and illusory perception, <a href='#Page_93'>93</a>, <a href='#Page_102'>102</a>, <a href='#Page_106'>106</a>;</span><br />
+<span style="margin-left: 2em;">nature of, <a href='#Page_295'>295</a>;</span><br />
+<span style="margin-left: 2em;">and memory, <a href='#Page_298'>298</a>;</span><br />
+<span style="margin-left: 2em;">of new experience, <a href='#Page_301'>301</a>;</span><br />
+<span style="margin-left: 2em;">of remote events, <a href='#Page_302'>302</a>;</span><br />
+<span style="margin-left: 2em;">measurement of duration in, <a href='#Page_302'>302</a>;</span><br />
+<span style="margin-left: 2em;">action of imagination in, <a href='#Page_305'>305</a>;</span><br />
+<span style="margin-left: 2em;">extension of meaning of, <a href='#Page_307'>307</a>, <a href='#Page_308'>308</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Experience, effect of, in perception, <a href='#Page_22'>22</a>, <a href='#Page_68'>68</a>, <a href='#Page_85'>85</a>, <a href='#Page_86'>86</a>, <a href='#Page_91'>91</a>;</span><br />
+<span style="margin-left: 2em;">external and internal, <a href='#Page_194'>194</a>, <a href='#Page_210'>210</a>;</span><br />
+<span style="margin-left: 2em;">revivals of waking, in dreams, <a href='#Page_152'>152</a>;</span><br />
+<span style="margin-left: 2em;">effects of present, on retrospection, <a href='#Page_267'>267</a>;</span><br />
+<span style="margin-left: 2em;">anticipation of new, <a href='#Page_301'>301</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">External world. <i>See</i> World.</span><br />
+<span class='pagenum'><a name="Page_366" id="Page_366">[Pg 366]</a></span><br />
+<br />
+<span style="margin-left: 1em;">F.</span><br />
+<br />
+<span style="margin-left: 1em;">Fallacy and illusion <a href='#Page_6'>6</a>, <a href='#Page_335'>335</a>;</span><br />
+<span style="margin-left: 2em;">of testimony, <a href='#Page_265'>265</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Familiarity, sense of, in new objects, <a href='#Page_272'>272</a>, <a href='#Page_281'>281</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Fechner, G.T., <a href='#Page_51'>51</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Ferrier, Dr., <a href='#Page_32'>32</a>, note<a href="#Footnote_12_12" class="fnanchor">[12]</a>, <a href='#Page_58'>58</a>, note<a href="#Footnote_26_26" class="fnanchor">[26]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Fiction, as producing illusion, <a href='#Page_278'>278</a>, <a href='#Page_279'>279</a>, <a href='#Page_311'>311</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Fitness. <i>See</i> Adaptation.</span><br />
+<br />
+<span style="margin-left: 1em;">Flattery, <i>rationale</i> of, <a href='#Page_200'>200</a>, <a href='#Page_222'>222</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Forgetfulness and illusion, <a href='#Page_278'>278</a>, <a href='#Page_279'>279</a>, <a href='#Page_311'>311</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Free-will, doctrine of, <a href='#Page_207'>207</a>, <a href='#Page_342'>342</a>, <a href='#Page_356'>356</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Future. <i>See</i> Expectation.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">G.</span><br />
+<br />
+<span style="margin-left: 1em;">Galton, F., <a href='#Page_117'>117</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Ghosts. <i>See</i> Hallucination.</span><br />
+<br />
+<span style="margin-left: 1em;">Goethe, <a href='#Page_116'>116</a>, <a href='#Page_117'>117</a>, <a href='#Page_280'>280</a> and note<a href="#Footnote_131_131" class="fnanchor">[131]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Griesinger, W., <a href='#Page_13'>13</a>, note<a href="#Footnote_2_2" class="fnanchor">[2]</a>, <a href='#Page_63'>63</a>, note<a href="#Footnote_31_31" class="fnanchor">[31]</a>, <a href='#Page_66'>66</a>, note<a href="#Footnote_32_32" class="fnanchor">[32]</a>, <a href='#Page_115'>115</a>, <a href='#Page_118'>118</a>, note<a href="#Footnote_62_62" class="fnanchor">[62]</a>,</span><br />
+<span style="margin-left: 2em;"><a href='#Page_119'>119</a>, note<a href="#Footnote_64_64" class="fnanchor">[64]</a> , <a href='#Page_120'>120</a>, note<a href="#Footnote_66_66" class="fnanchor">[66]</a>, <a href='#Page_290'>290</a>, note<a href="#Footnote_135_135" class="fnanchor">[135]</a>, <a href='#Page_327'>327</a>, note<a href="#Footnote_146_146" class="fnanchor">[146]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Gruithuisen, <a href='#Page_143'>143</a>, <a href='#Page_144'>144</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Gurney, E., <a href='#Page_224'>224</a>, note<a href="#Footnote_109_109" class="fnanchor">[109]</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">H.</span><br />
+<br />
+<span style="margin-left: 1em;">Hall, G.S., <a href='#Page_186'>186</a>, note<a href="#Footnote_102_102" class="fnanchor">[102]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hallucination, and illusion, <a href='#Page_11'>11</a>, <a href='#Page_109'>109</a>, <a href='#Page_111'>111</a>, <a href='#Page_112'>112</a>, <a href='#Page_121'>121</a>;</span><br />
+<span style="margin-left: 2em;">and subjective sensation, <a href='#Page_63'>63</a>, <a href='#Page_109'>109</a>, <a href='#Page_121'>121</a>;</span><br />
+<span style="margin-left: 2em;">sensory and motor, <a href='#Page_66'>66</a>;</span><br />
+<span style="margin-left: 2em;">nervous conditions of, <a href='#Page_112'>112-114</a>;</span><br />
+<span style="margin-left: 2em;">incomplete and complete, <a href='#Page_113'>113</a>;</span><br />
+<span style="margin-left: 2em;">as having either central or peripheral origin, <a href='#Page_113'>113</a>;</span><br />
+<span style="margin-left: 2em;">causes of, classified, <a href='#Page_115'>115</a>;</span><br />
+<span style="margin-left: 2em;">in sane condition, <a href='#Page_116'>116</a>;</span><br />
+<span style="margin-left: 2em;">in insanity, <a href='#Page_118'>118</a>;</span><br />
+<span style="margin-left: 2em;">visual and auditory, <a href='#Page_119'>119</a>;</span><br />
+<span style="margin-left: 2em;">dreams regarded as, <a href='#Page_139'>139</a>, <a href='#Page_151'>151</a>;</span><br />
+<span style="margin-left: 2em;">hypnagogic, <a href='#Page_143'>143</a>;</span><br />
+<span style="margin-left: 2em;">after-dreams and ghosts, <a href='#Page_183'>183</a>;</span><br />
+<span style="margin-left: 2em;">of memory, <a href='#Page_271'>271</a>;</span><br />
+<span style="margin-left: 2em;">relation of, to errors of belief, <a href='#Page_322'>322</a>;</span><br />
+<span style="margin-left: 2em;">intuition of external world regarded as, <a href='#Page_355'>355</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Happiness, feeling of, <a href='#Page_200'>200</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Harmful, illusion as, <a href='#Page_188'>188</a>, <a href='#Page_229'>229</a>, <a href='#Page_292'>292</a>, <a href='#Page_339'>339</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Harmless, illusions as, <a href='#Page_124'>124</a>, <a href='#Page_292'>292</a>, <a href='#Page_341'>341</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hartley, D., <a href='#Page_139'>139</a>, <a href='#Page_256'>256</a>, note<a href="#Footnote_124_124" class="fnanchor">[124]</a>, <a href='#Page_279'>279</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hearing, as mode of perception, <a href='#Page_34'>34</a>, <a href='#Page_48'>48</a>;</span><br />
+<span style="margin-left: 2em;">localization of impression in, <a href='#Page_60'>60</a>;</span><br />
+<span style="margin-left: 2em;">sense of direction in, <a href='#Page_72'>72</a>;</span><br />
+<span style="margin-left: 2em;">activity of, in sleep, <a href='#Page_140'>140</a>;</span><br />
+<span style="margin-left: 2em;">and muscular sense, <a href='#Page_171'>171</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Heidenhain, Dr., <a href='#Page_186'>186-188</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Helmholtz, H., <a href='#Page_22'>22</a>, <a href='#Page_23'>23</a>, note<a href="#Footnote_7_7" class="fnanchor">[7]</a>, <a href='#Page_44'>44</a>, <a href='#Page_51'>51</a>, <a href='#Page_54'>54</a> and note<a href="#Footnote_22_22" class="fnanchor">[22]</a>, <a href='#Page_55'>55</a>, note<a href="#Footnote_23_23" class="fnanchor">[23]</a>,</span><br />
+<span style="margin-left: 2em;"><a href='#Page_57'>57</a>, <a href='#Page_67'>67</a>, note<a href="#Footnote_33_33" class="fnanchor">[33]</a>, <a href='#Page_78'>78</a>, note<a href="#Footnote_39_39" class="fnanchor">[39]</a>, <a href='#Page_80'>80</a>, <a href='#Page_85'>85</a>, note<a href="#Footnote_43_43" class="fnanchor">[43]</a>, <a href='#Page_88'>88</a>, <a href='#Page_90'>90</a>, <a href='#Page_207'>207</a>, note<a href="#Footnote_105_105" class="fnanchor">[105]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Heraclitus, <a href='#Page_137'>137</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Heredity, and illusion of memory, <a href='#Page_280'>280</a>;</span><br />
+<span style="margin-left: 2em;">action of, in perpetuating intuition, <a href='#Page_359'>359</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hering, E., <a href='#Page_67'>67</a>, note<a href="#Footnote_33_33" class="fnanchor">[33]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hodgson, Shadworth H., <a href='#Page_347'>347</a>, note<a href="#Footnote_153_153" class="fnanchor">[153]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Holland, Sir H., <a href='#Page_277'>277</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hood, Thomas, <a href='#Page_146'>146</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hope, illusory. <i>See</i> Expectation.</span><br />
+<br />
+<span style="margin-left: 1em;">Hoppe, Dr. J.I., <a href='#Page_51'>51</a>, <a href='#Page_58'>58</a>, note<a href="#Footnote_26_26" class="fnanchor">[26]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Horwicz, A., <a href='#Page_145'>145</a>, note<a href="#Footnote_85_85" class="fnanchor">[85]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hume, D., <a href='#Page_355'>355</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Huxley, Professor T., <a href='#Page_119'>119</a>, note<a href="#Footnote_63_63" class="fnanchor">[63]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hyper&aelig;sthesia, <a href='#Page_65'>65</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hypnotism, <a href='#Page_185'>185</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hypochondria, <a href='#Page_65'>65</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Hypothesis, as illusory, <a href='#Page_310'>310</a>, <a href='#Page_311'>311</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">I.</span><br />
+<br />
+<span style="margin-left: 1em;">Idealism, <a href='#Page_348'>348</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Identity, cases of mistaken, <a href='#Page_267'>267</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Identity, personal, confusion of, in dreams, <a href='#Page_163'>163</a>;</span><br />
+<span style="margin-left: 2em;">consciousness of, <a href='#Page_241'>241</a>, <a href='#Page_267'>267</a>, <a href='#Page_282'>282</a>, <a href='#Page_285'>285</a>;</span><br />
+<span style="margin-left: 2em;">illusory forms of, <a href='#Page_283'>283</a>;</span><br />
+<span style="margin-left: 2em;">gross disturbances of, in normal life, <a href='#Page_287'>287</a>;</span><br />
+<span style="margin-left: 2em;">in abnormal life, <a href='#Page_289'>289</a>;</span><br />
+<span style="margin-left: 2em;">momentary confusions of, <a href='#Page_293'>293</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Illusion, definition of, <a href='#Page_1'>1</a>;</span><br />
+<span style="margin-left: 2em;">varieties of, <a href='#Page_9'>9</a>;</span><br />
+<span style="margin-left: 2em;">extent of, <a href='#Page_328'>328</a>;</span><br />
+<span style="margin-left: 2em;"><i>rationale</i> of, <a href='#Page_331'>331</a>, <a href='#Page_337'>337</a>.</span><br />
+<span class='pagenum'><a name="Page_367" id="Page_367">[Pg 367]</a></span><br />
+<span style="margin-left: 1em;">Image (physical). <i>See</i> Reflection.</span><br />
+<br />
+<span style="margin-left: 1em;">Image (mental), in perception, <a href='#Page_22'>22</a>;</span><br />
+<span style="margin-left: 2em;">seat of, <a href='#Page_32'>32</a>;</span><br />
+<span style="margin-left: 2em;">in dreams, <a href='#Page_138'>138</a>;</span><br />
+<span style="margin-left: 2em;">mnemonic, <a href='#Page_236'>236</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Imagination, play of, in perception, <a href='#Page_95'>95</a>, <a href='#Page_99'>99</a>;</span><br />
+<span style="margin-left: 2em;">and sense-illusion, <a href='#Page_106'>106</a>;</span><br />
+<span style="margin-left: 2em;">nature of, in dreaming, <a href='#Page_136'>136</a>, <a href='#Page_161'>161</a>;</span><br />
+<span style="margin-left: 2em;">as antecedent of dream, <a href='#Page_152'>152</a>, <a href='#Page_158'>158</a>;</span><br />
+<span style="margin-left: 2em;">as poetic interpretation of nature, <a href='#Page_224'>224</a>;</span><br />
+<span style="margin-left: 2em;">memory corrupted by effect of past, <a href='#Page_264'>264</a>, <a href='#Page_273'>273</a>, <a href='#Page_277'>277</a>;</span><br />
+<span style="margin-left: 2em;">present, creating the semblance of recollection, <a href='#Page_267'>267</a>, <a href='#Page_271'>271</a>;</span><br />
+<span style="margin-left: 2em;">play of, in expectation, <a href='#Page_305'>305</a>;</span><br />
+<span style="margin-left: 2em;">as element of illusion generally, <a href='#Page_333'>333</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Immediate. <i>See</i> Cognition.</span><br />
+<br />
+<span style="margin-left: 1em;">Individual, and common experience, <a href='#Page_26'>26</a>, <a href='#Page_27'>27</a>, <a href='#Page_137'>137</a>, <a href='#Page_209'>209</a>, <a href='#Page_214'>214</a>, <a href='#Page_336'>336</a>;</span><br />
+<span style="margin-left: 2em;">dream-experience as, <a href='#Page_44'>44</a>, <a href='#Page_68'>68</a>;</span><br />
+<span style="margin-left: 2em;">internal experience as, <a href='#Page_209'>209</a>;</span><br />
+<span style="margin-left: 2em;">memory as, <a href='#Page_232'>232</a>;</span><br />
+<span style="margin-left: 2em;">belief and truth, <a href='#Page_338'>338</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Inference, and immediate knowledge, <a href='#Page_6'>6</a>, <a href='#Page_334'>334</a>;</span><br />
+<span style="margin-left: 2em;">in perception, <a href='#Page_22'>22</a>, <a href='#Page_26'>26</a>, <a href='#Page_68'>68</a>;</span><br />
+<span style="margin-left: 2em;">in belief, <a href='#Page_295'>295</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Innate, recollection as, <a href='#Page_280'>280</a>;</span><br />
+<span style="margin-left: 2em;">principles, <a href='#Page_295'>295</a>, <a href='#Page_356'>356</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Insane, sense-illusions of, <a href='#Page_63'>63</a>, <a href='#Page_65'>65</a>, <a href='#Page_111'>111</a>;</span><br />
+<span style="margin-left: 2em;">hallucinations of, <a href='#Page_118'>118</a>;</span><br />
+<span style="margin-left: 2em;">dreaming and state of, <a href='#Page_182'>182</a>;</span><br />
+<span style="margin-left: 2em;">mnemonic illusions of, <a href='#Page_278'>278</a>, <a href='#Page_289'>289</a>;</span><br />
+<span style="margin-left: 2em;">beliefs of, <a href='#Page_327'>327</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Insight, nature of, <a href='#Page_217'>217</a>;</span><br />
+<span style="margin-left: 2em;">illusions of, defined, <a href='#Page_220'>220</a>;</span><br />
+<span style="margin-left: 2em;">passive illusions of, <a href='#Page_220'>220</a>;</span><br />
+<span style="margin-left: 2em;">histrionic illusion, <a href='#Page_222'>222</a>;</span><br />
+<span style="margin-left: 2em;">active illusions of, <a href='#Page_223'>223</a>;</span><br />
+<span style="margin-left: 2em;">poetic interpretation of nature, <a href='#Page_224'>224</a>;</span><br />
+<span style="margin-left: 2em;">value of faculty of, <a href='#Page_228'>228</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Interpretation, in correct perception, <a href='#Page_22'>22</a>;</span><br />
+<span style="margin-left: 2em;">of impression and experience, <a href='#Page_70'>70</a>;</span><br />
+<span style="margin-left: 2em;">and volition, <a href='#Page_95'>95</a>;</span><br />
+<span style="margin-left: 2em;">and fixed habits of mind, <a href='#Page_101'>101</a>;</span><br />
+<span style="margin-left: 2em;">and temporary attitude of mind, <a href='#Page_102'>102</a>;</span><br />
+<span style="margin-left: 2em;">of sensations in dreams, <a href='#Page_137'>137</a>, <a href='#Page_147'>147</a>;</span><br />
+<span style="margin-left: 2em;">of internal feelings, <a href='#Page_203'>203</a>;</span><br />
+<span style="margin-left: 2em;">of others' feelings, <a href='#Page_217'>217</a>;</span><br />
+<span style="margin-left: 2em;">of nature by poet, <a href='#Page_225'>225</a>;</span><br />
+<span style="margin-left: 2em;">recollection as, <a href='#Page_242'>242</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Introspection, nature of, <a href='#Page_14'>14</a>, <a href='#Page_189'>189</a>;</span><br />
+<span style="margin-left: 2em;">illusory forms of, <a href='#Page_190'>190</a>;</span><br />
+<span style="margin-left: 2em;">confusion of inner and outer experiences, <a href='#Page_194'>194</a>;</span><br />
+<span style="margin-left: 2em;">inaccurate inspection of feelings, <a href='#Page_196'>196</a>;</span><br />
+<span style="margin-left: 2em;">presentation and representation confused, <a href='#Page_199'>199</a>;</span><br />
+<span style="margin-left: 2em;">feelings and inferences from these, <a href='#Page_203'>203</a>;</span><br />
+<span style="margin-left: 2em;">moral self-scrutiny, <a href='#Page_204'>204</a>;</span><br />
+<span style="margin-left: 2em;">philosophic, <a href='#Page_205'>205</a>;</span><br />
+<span style="margin-left: 2em;">value of, <a href='#Page_208'>208</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Intuition. <i>See</i> Cognition.</span><br />
+<br />
+<span style="margin-left: 1em;">Intuitivism, <a href='#Page_348'>348</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">J.</span><br />
+<br />
+<span style="margin-left: 1em;">Jackson, Dr. J. Hughlings, <a href='#Page_27'>27</a>, note<a href="#Footnote_9_9" class="fnanchor">[9]</a>, <a href='#Page_33'>33</a>, <a href='#Page_123'>123</a>, note<a href="#Footnote_67_67" class="fnanchor">[67]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Johnson, Dr., <a href='#Page_116'>116</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">K.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Klang</i>, as compound sensation, <a href='#Page_53'>53</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Knowledge. <i>See</i> Cognition.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">L.</span><br />
+<br />
+<span style="margin-left: 1em;">Language, function of, <a href='#Page_195'>195</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Leibnitz, <a href='#Page_133'>133</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">L&eacute;lut, L.F., <a href='#Page_120'>120</a>, note<a href="#Footnote_66_66" class="fnanchor">[66]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Lessing, G. E., <a href='#Page_133'>133</a>, note<a href="#Footnote_73_73" class="fnanchor">[73]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Leuret, <a href='#Page_290'>290</a>, note<a href="#Footnote_135_135" class="fnanchor">[135]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Lewes, G.H., <a href='#Page_28'>28</a>, <a href='#Page_32'>32</a>, note<a href="#Footnote_12_12" class="fnanchor">[12]</a>, <a href='#Page_52'>52</a>, note<a href="#Footnote_18_18" class="fnanchor">[18]</a>, <a href='#Page_62'>62</a>, note<a href="#Footnote_30_30" class="fnanchor">[30]</a>, <a href='#Page_68'>68</a>,</span><br />
+<span style="margin-left: 2em;">note<a href="#Footnote_35_35" class="fnanchor">[35]</a>, <a href='#Page_89'>89</a>, note<a href="#Footnote_45_45" class="fnanchor">[45]</a>, <a href='#Page_115'>115</a>, note<a href="#Footnote_58_58" class="fnanchor">[58]</a>, <a href='#Page_150'>150</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Life, our estimate of, <a href='#Page_323'>323</a>, <a href='#Page_326'>326</a>, <a href='#Page_327'>327</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Light, sensation and perception of, <a href='#Page_59'>59</a>;</span><br />
+<span style="margin-left: 2em;">effects of reflection and refraction, of, <a href='#Page_73'>73</a>;</span><br />
+<span style="margin-left: 2em;">representation, of, in painting, <a href='#Page_88'>88</a>, <a href='#Page_91'>91</a>;</span><br />
+<span style="margin-left: 2em;">action of, in sleep, <a href='#Page_140'>140</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Localization, as local discrimination of sensations, <a href='#Page_52'>52</a>;</span><br />
+<span style="margin-left: 2em;">as localizing of sensations, <a href='#Page_59'>59</a>, <a href='#Page_60'>60</a>;</span><br />
+<span style="margin-left: 2em;">illusory, <a href='#Page_61'>61</a>, <a href='#Page_82'>82</a>;</span><br />
+<span style="margin-left: 2em;">in hallucination, <a href='#Page_118'>118</a>, <a href='#Page_119'>119</a>;</span><br />
+<span style="margin-left: 2em;">in dreaming, <a href='#Page_148'>148</a>;</span><br />
+<span style="margin-left: 2em;">of events in time, in memory, <a href='#Page_238'>238</a>, <a href='#Page_245'>245</a>;</span><br />
+<span style="margin-left: 2em;">in expectation, <a href='#Page_304'>304</a>.</span><br />
+<span class='pagenum'><a name="Page_368" id="Page_368">[Pg 368]</a></span><br />
+<span style="margin-left: 1em;">Locke, <a href='#Page_133'>133</a>, note<a href="#Footnote_73_73" class="fnanchor">[73]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Lotze, H., <a href='#Page_60'>60</a>, note<a href="#Footnote_29_29" class="fnanchor">[29]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Lover, illusion of, <a href='#Page_224'>224</a>, <a href='#Page_227'>227</a>, <a href='#Page_342'>342</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Luminosity of painting, <a href='#Page_88'>88</a>, <a href='#Page_91'>91</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Lustre, as compound sensation, <a href='#Page_54'>54</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Lyell, Sir Charles, <a href='#Page_311'>311</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">M.</span><br />
+<br />
+<span style="margin-left: 1em;">Magic, arts of, <a href='#Page_73'>73</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Magnitude, apparent, in vision, <a href='#Page_75'>75</a>, note<a href="#Footnote_37_37" class="fnanchor">[37]</a>;</span><br />
+<span style="margin-left: 2em;">perception of, in pictorial art, <a href='#Page_88'>88</a>, <a href='#Page_91'>91</a>;</span><br />
+<span style="margin-left: 2em;">of time-intervals, <a href='#Page_245'>245</a>, <a href='#Page_249'>249</a>;</span><br />
+<span style="margin-left: 2em;">recollection of, <a href='#Page_268'>268</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Malebranche, <a href='#Page_116'>116</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Mankind, our views of, <a href='#Page_322'>322</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Matter. <i>See</i> World (material).</span><br />
+<br />
+<span style="margin-left: 1em;">Maudsley, Dr. H., <a href='#Page_32'>32</a>, note<a href="#Footnote_12_12" class="fnanchor">[12]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Maury, A., <a href='#Page_140'>140</a>, <a href='#Page_143'>143</a>, <a href='#Page_153'>153</a>, note<a href="#Footnote_92_92" class="fnanchor">[92]</a>, <a href='#Page_159'>159</a>, <a href='#Page_163'>163</a>, note<a href="#Footnote_94_94" class="fnanchor">[94]</a> ,<a href='#Page_173'>173</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Mayer, Dr. A., <a href='#Page_66'>66</a>, note<a href="#Footnote_32_32" class="fnanchor">[32]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Measurement, subjective, of time, <a href='#Page_245'>245</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Media, coloured, illusions connected with presence of, <a href='#Page_82'>82</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Memory, nature of, <a href='#Page_9'>9</a>, <a href='#Page_13'>13</a>, <a href='#Page_231'>231</a>;</span><br />
+<span style="margin-left: 2em;">veracity of, <a href='#Page_232'>232</a>, <a href='#Page_290'>290</a>;</span><br />
+<span style="margin-left: 2em;">defined, <a href='#Page_234'>234</a>;</span><br />
+<span style="margin-left: 2em;">psychology of, <a href='#Page_236'>236</a>;</span><br />
+<span style="margin-left: 2em;">physiology of, <a href='#Page_237'>237</a>;</span><br />
+<span style="margin-left: 2em;">localization of events in, <a href='#Page_238'>238</a>;</span><br />
+<span style="margin-left: 2em;">and sense of personal identity, <a href='#Page_241'>241</a>, <a href='#Page_283'>283</a>;</span><br />
+<span style="margin-left: 2em;">illusions of, <a href='#Page_241'>241</a>;</span><br />
+<span style="margin-left: 2em;">illusory localization, <a href='#Page_245'>245</a>, <a href='#Page_256'>256</a>;</span><br />
+<span style="margin-left: 2em;">distortions of, <a href='#Page_261'>261</a>;</span><br />
+<span style="margin-left: 2em;">hallucinations of, <a href='#Page_271'>271</a>;</span><br />
+<span style="margin-left: 2em;">illusions respecting personal identity, <a href='#Page_283'>283</a>;</span><br />
+<span style="margin-left: 2em;">relation of, to belief, <a href='#Page_295'>295</a>;</span><br />
+<span style="margin-left: 2em;">compared with expectation, <a href='#Page_297'>297</a>;</span><br />
+<span style="margin-left: 2em;">and inference, <a href='#Page_335'>335</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Metempsychosis, <a href='#Page_294'>294</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Meyer, H., <a href='#Page_83'>83</a>, <a href='#Page_144'>144</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Mill, J.S., <a href='#Page_298'>298</a>, note<a href="#Footnote_138_138" class="fnanchor">[138]</a>, <a href='#Page_309'>309</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Mirrors, as means of delusion, <a href='#Page_73'>73</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Misanthropist, <a href='#Page_2'>2</a>, <a href='#Page_323'>323</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Mitchell, Dr. Weir, <a href='#Page_62'>62</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Monomania, <a href='#Page_111'>111</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Moral, intuition, <a href='#Page_216'>216</a>;</span><br />
+<span style="margin-left: 2em;">self-inspection, <a href='#Page_204'>204</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Motor illusions. <i>See</i> Muscular sense.</span><br />
+<br />
+<span style="margin-left: 1em;">Movement, apparent, <a href='#Page_50'>50</a>, <a href='#Page_57'>57</a>, <a href='#Page_73'>73</a>, <a href='#Page_81'>81</a>, <a href='#Page_95'>95</a>, <a href='#Page_107'>107</a>;</span><br />
+<span style="margin-left: 2em;">in dreams, <a href='#Page_142'>142</a>, <a href='#Page_154'>154</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">M&uuml;ller, Johannes, <a href='#Page_58'>58</a>, note<a href="#Footnote_27_27" class="fnanchor">[27]</a>, <a href='#Page_100'>100</a>, <a href='#Page_117'>117</a>, <a href='#Page_143'>143</a>.</span><br />
+<br />
+<span style="margin-left: 1em;"><i>Musc&aelig; volitantes</i>, <a href='#Page_118'>118</a>, note<a href="#Footnote_62_62" class="fnanchor">[62]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Muscular sense, in perception, <a href='#Page_23'>23</a>;</span><br />
+<span style="margin-left: 2em;">illusions connected with, <a href='#Page_50'>50</a>, <a href='#Page_57'>57</a>, <a href='#Page_62'>62</a>, <a href='#Page_66'>66</a>;</span><br />
+<span style="margin-left: 2em;">co-operation, of, in dreams, <a href='#Page_142'>142</a>, <a href='#Page_154'>154</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Music, subjective interpretation of, <a href='#Page_223'>223</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">N.</span><br />
+<br />
+<span style="margin-left: 1em;">Natural selection, effect of, in eliminating error, <a href='#Page_340'>340</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Nature, personification of, <a href='#Page_224'>224</a>;</span><br />
+<span style="margin-left: 2em;">uniformity of, <a href='#Page_344'>344</a>, <a href='#Page_360'>360</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Necessity, idea of, <a href='#Page_349'>349</a>, <a href='#Page_360'>360</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Nervous system, and conditions of perception, <a href='#Page_31'>31</a>;</span><br />
+<span style="margin-left: 2em;">connections of, <a href='#Page_32'>32</a>, <a href='#Page_169'>169</a>;</span><br />
+<span style="margin-left: 2em;">function of, and force of stimulus, <a href='#Page_47'>47</a>, <a href='#Page_50'>50</a>;</span><br />
+<span style="margin-left: 2em;">prolonged activity of, <a href='#Page_55'>55</a>;</span><br />
+<span style="margin-left: 2em;">specific energy of, <a href='#Page_58'>58</a>;</span><br />
+<span style="margin-left: 2em;">variations in state of, <a href='#Page_64'>64</a>;</span><br />
+<span style="margin-left: 2em;">fatigue of, <a href='#Page_65'>65</a>, <a href='#Page_115'>115</a>;</span><br />
+<span style="margin-left: 2em;">disease of, <i>ibid.</i>;</span><br />
+<span style="margin-left: 2em;">nervous conditions of hallucination, <a href='#Page_112'>112</a>, <a href='#Page_115'>115</a>;</span><br />
+<span style="margin-left: 2em;">nervous dissolution and evolution, <a href='#Page_122'>122</a>;</span><br />
+<span style="margin-left: 2em;">condition of, in sleep, <a href='#Page_131'>131</a>;</span><br />
+<span style="margin-left: 2em;">in hypnotic condition, <a href='#Page_186'>186</a>;</span><br />
+<span style="margin-left: 2em;">nervous conditions of memory, <a href='#Page_237'>237</a>;</span><br />
+<span style="margin-left: 2em;">nervous conditions of illusion in general, <a href='#Page_334'>334</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Normal life, relation of,</span><br />
+<span style="margin-left: 2em;">to abnormal, <a href='#Page_1'>1</a>, <a href='#Page_121'>121</a>, <a href='#Page_124'>124</a>, <a href='#Page_182'>182</a>, <a href='#Page_277'>277</a>, <a href='#Page_284'>284</a>, note<a href="#Footnote_132_132" class="fnanchor">[132]</a>;</span><br />
+<span style="margin-left: 2em;">hallucinations of, <a href='#Page_116'>116</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">O.</span><br />
+<br />
+<span style="margin-left: 1em;">Object, nature of, <a href='#Page_36'>36</a>, <a href='#Page_353'>353</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Objective and subjective experience, <a href='#Page_26'>26</a>, <a href='#Page_27'>27</a>, <a href='#Page_137'>137</a>, <a href='#Page_214'>214</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Old age, dreams how regarded in, <a href='#Page_276'>276</a>.</span><br />
+<span class='pagenum'><a name="Page_369" id="Page_369">[Pg 369]</a></span><br />
+<span style="margin-left: 1em;">Oneirocritics, <a href='#Page_129'>129</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Opera, illusion connected with, <a href='#Page_104'>104</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Optimism, <a href='#Page_323'>323</a>, <a href='#Page_327'>327</a>, <a href='#Page_342'>342</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Organic sensations, discrimination of, <a href='#Page_41'>41</a>;</span><br />
+<span style="margin-left: 2em;">interpretation of, <a href='#Page_99'>99</a>;</span><br />
+<span style="margin-left: 2em;">in sleep, <a href='#Page_145'>145</a>, <a href='#Page_148'>148</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Organism, conditions of illusion in, <a href='#Page_47'>47</a>, <a href='#Page_50'>50</a>;</span><br />
+<span style="margin-left: 2em;">relation of our conception of the universe to sensibilities of, <a href='#Page_343'>343</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Orientation, <a href='#Page_125'>125</a>, <a href='#Page_138'>138</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">P.</span><br />
+<br />
+<span style="margin-left: 1em;">Pain, recollection of, <a href='#Page_264'>264</a>, <a href='#Page_270'>270</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Painting, representation of third dimension by, <a href='#Page_77'>77</a>;</span><br />
+<span style="margin-left: 2em;">apparent movement of eye in portrait, <a href='#Page_81'>81</a>;</span><br />
+<span style="margin-left: 2em;">discrepancies between, and object in magnitude and luminosity, <a href='#Page_88'>88</a>;</span><br />
+<span style="margin-left: 2em;">realization of, and mental preparation, <a href='#Page_105'>105</a>;</span><br />
+<span style="margin-left: 2em;">realization of, by animals, <a href='#Page_105'>105</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Par&aelig;sthesia, <a href='#Page_68'>68</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Paralysis of ocular muscles, <a href='#Page_66'>66</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Passive, and active factor in perception, <a href='#Page_27'>27</a>;</span><br />
+<span style="margin-left: 2em;">and active illusion, <a href='#Page_45'>45</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Percept, <a href='#Page_22'>22</a>;</span><br />
+<span style="margin-left: 2em;">and sense-impression, <a href='#Page_59'>59</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Perception, a form of immediate knowledge, <a href='#Page_10'>10</a>, <a href='#Page_13'>13</a>, <a href='#Page_17'>17</a>, <a href='#Page_18'>18</a>;</span><br />
+<span style="margin-left: 2em;">external and internal, <a href='#Page_14'>14</a>;</span><br />
+<span style="margin-left: 2em;">philosophy of, <a href='#Page_14'>14</a>, <a href='#Page_20'>20</a>, <a href='#Page_22'>22</a>, <a href='#Page_36'>36</a>, <a href='#Page_346'>346</a>, <a href='#Page_348'>348</a>, <a href='#Page_353'>353</a>, <a href='#Page_355'>355</a>, <a href='#Page_359'>359</a>;</span><br />
+<span style="margin-left: 2em;">illusions of, <a href='#Page_19'>19</a>, <a href='#Page_35'>35</a>;</span><br />
+<span style="margin-left: 2em;">psychology of, <a href='#Page_20'>20</a>;</span><br />
+<span style="margin-left: 2em;">and inference, <a href='#Page_22'>22</a>, <a href='#Page_26'>26</a>, <a href='#Page_76'>76</a>;</span><br />
+<span style="margin-left: 2em;">physiological conditions of, <a href='#Page_31'>31</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Persistent objects, representation of, <a href='#Page_312'>312</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Persistent self. <i>See</i> Personal identity.</span><br />
+<br />
+<span style="margin-left: 1em;">Personal equation, in perception, <a href='#Page_101'>101</a>;</span><br />
+<span style="margin-left: 2em;">in &aelig;sthetic intuition, <a href='#Page_214'>214</a>;</span><br />
+<span style="margin-left: 2em;">in memory, <a href='#Page_292'>292</a>;</span><br />
+<span style="margin-left: 2em;">in belief, <a href='#Page_324'>324</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Personal identity, consciousness of, <a href='#Page_241'>241</a>, <a href='#Page_282'>282</a>, <a href='#Page_285'>285</a>;</span><br />
+<span style="margin-left: 2em;">illusions connected with, <a href='#Page_283'>283</a>;</span><br />
+<span style="margin-left: 2em;">disturbances in sense of, <a href='#Page_287'>287</a>;</span><br />
+<span style="margin-left: 2em;">sense of, in insanity, <a href='#Page_289'>289</a>;</span><br />
+<span style="margin-left: 2em;">momentary confusions of, <a href='#Page_293'>293</a>;</span><br />
+<span style="margin-left: 2em;">philosophic problem of, <a href='#Page_285'>285</a>, <a href='#Page_354'>354</a>, <a href='#Page_360'>360</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Personification of nature, <a href='#Page_224'>224</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Perspective, linear, <a href='#Page_79'>79</a>, <a href='#Page_97'>97</a>, <a href='#Page_98'>98</a>;</span><br />
+<span style="margin-left: 2em;">aerial, <a href='#Page_80'>80</a>;</span><br />
+<span style="margin-left: 2em;">of memory, <a href='#Page_245'>245</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Pessimism, <a href='#Page_323'>323</a>, <a href='#Page_327'>327</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Phenomenalism, <a href='#Page_348'>348</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Philosophy, conception of illusion by, <a href='#Page_7'>7</a>, <a href='#Page_36'>36</a>, <a href='#Page_205'>205</a>, <a href='#Page_285'>285</a>, <a href='#Page_349'>349</a>;</span><br />
+<span style="margin-left: 2em;">of mind, <a href='#Page_132'>132</a>, <a href='#Page_285'>285</a>, <a href='#Page_344'>344</a>, <a href='#Page_348'>348</a>;</span><br />
+<span style="margin-left: 2em;">as theory of knowledge, <a href='#Page_295'>295</a>, <a href='#Page_346'>346</a>;</span><br />
+<span style="margin-left: 2em;">and science, <a href='#Page_346'>346</a>, <a href='#Page_348'>348</a>;</span><br />
+<span style="margin-left: 2em;">and common sense, <a href='#Page_347'>347</a>, <a href='#Page_349'>349</a>;</span><br />
+<span style="margin-left: 2em;">problems of, <a href='#Page_347'>347</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Phosphenes, <a href='#Page_58'>58</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Physical science. <i>See</i> Science.</span><br />
+<br />
+<span style="margin-left: 1em;">Plato, <a href='#Page_281'>281</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Platonists, <a href='#Page_349'>349</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Pleasure, feeling of, <a href='#Page_200'>200</a>;</span><br />
+<span style="margin-left: 2em;">recollection of, <a href='#Page_264'>264</a>, <a href='#Page_270'>270</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Plutarch, <a href='#Page_133'>133</a>, note<a href="#Footnote_73_73" class="fnanchor">[73]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Poetry, lyrical and dreams, <a href='#Page_164'>164</a>;</span><br />
+<span style="margin-left: 2em;">misinterpretation of, <a href='#Page_223'>223</a>;</span><br />
+<span style="margin-left: 2em;">personification, <a href='#Page_224'>224</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Points, discrimination of, <a href='#Page_52'>52</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Poisons, action of, <a href='#Page_115'>115</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Pollock, F., <a href='#Page_184'>184</a>, note<a href="#Footnote_101_101" class="fnanchor">[101]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Pollock, W.H., <a href='#Page_184'>184</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Predisposition, action of, in perception, <a href='#Page_44'>44</a>, <a href='#Page_101'>101</a>, <a href='#Page_102'>102</a>;</span><br />
+<span style="margin-left: 2em;">in &aelig;sthetic intuition, <a href='#Page_215'>215</a>;</span><br />
+<span style="margin-left: 2em;">in insight, <a href='#Page_223'>223</a>;</span><br />
+<span style="margin-left: 2em;">in recollection, <a href='#Page_268'>268</a>;</span><br />
+<span style="margin-left: 2em;">in belief, <a href='#Page_305'>305</a>, <a href='#Page_319'>319</a>;</span><br />
+<span style="margin-left: 2em;">belief as, <a href='#Page_324'>324</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Prejudice. <i>See</i> Predisposition.</span><br />
+<br />
+<span style="margin-left: 1em;">Prenatal experience, recollection of, <a href='#Page_281'>281</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Preperception, <a href='#Page_27'>27</a>;</span><br />
+<span style="margin-left: 2em;">illusions connected with, <a href='#Page_44'>44</a>, <a href='#Page_93'>93</a>;</span><br />
+<span style="margin-left: 2em;">voluntary, <a href='#Page_95'>95</a>;</span><br />
+<span style="margin-left: 2em;">result of habit of mind, <a href='#Page_101'>101</a>;</span><br />
+<span style="margin-left: 2em;">result of temporary conditions, <a href='#Page_102'>102</a>;</span><br />
+<span style="margin-left: 2em;">as sub-expectation, <a href='#Page_102'>102</a>;</span><br />
+<span style="margin-left: 2em;">as definite expectation, <a href='#Page_106'>106</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Presentation and representation, <a href='#Page_9'>9</a>, <a href='#Page_10'>10</a>, <a href='#Page_13'>13</a>, <a href='#Page_14'>14</a>, <a href='#Page_192'>192</a>, <a href='#Page_234'>234</a>, <a href='#Page_329'>329</a>, <a href='#Page_330'>330</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Projection, outward, of sensations, <a href='#Page_63'>63</a>;</span><br />
+<span class='pagenum'><a name="Page_370" id="Page_370">[Pg 370]</a></span><span style="margin-left: 2em;">of mental image, <a href='#Page_111'>111</a>, <a href='#Page_112'>112</a>;</span><br />
+<span style="margin-left: 2em;">of solid form on flat, <a href='#Page_79'>79</a>, <a href='#Page_81'>81</a>, <a href='#Page_96'>96</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Prophetic, dreams as, <a href='#Page_129'>129</a>, <a href='#Page_147'>147</a>, note<a href="#Footnote_88_88" class="fnanchor">[88]</a>;</span><br />
+<span style="margin-left: 2em;">enthusiast, <a href='#Page_307'>307</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Psychology, popular and scientific, <a href='#Page_9'>9</a>, <a href='#Page_10'>10</a>;</span><br />
+<span style="margin-left: 2em;">distinguished from philosophy, <a href='#Page_14'>14</a>, <a href='#Page_36'>36</a>, <a href='#Page_345'>345</a>, <a href='#Page_352'>352</a>;</span><br />
+<span style="margin-left: 2em;">introspective method of, <a href='#Page_208'>208</a>;</span><br />
+<span style="margin-left: 2em;">as a kind of philosophy, <a href='#Page_305'>305</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Public events, localization, of, by memory, <a href='#Page_258'>258</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">R.</span><br />
+<br />
+<span style="margin-left: 1em;">Radestock, P., <a href='#Page_130'>130</a>, note<a href="#Footnote_71_71" class="fnanchor">[71]</a>, <a href='#Page_132'>132</a>, note<a href="#Footnote_72_72" class="fnanchor">[72]</a>, <a href='#Page_134'>134</a>, note<a href="#Footnote_75_75" class="fnanchor">[75]</a>, <a href='#Page_140'>140</a>, <a href='#Page_141'>141</a>,</span><br />
+<span style="margin-left: 2em;"><a href='#Page_149'>149</a>, note<a href="#Footnote_90_90" class="fnanchor">[90]</a>, <a href='#Page_162'>162</a>, <a href='#Page_182'>182</a>, <a href='#Page_275'>275</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Rationalism, philosophic, <a href='#Page_348'>348</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Realism, <a href='#Page_348'>348</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Reality, nature of, <a href='#Page_36'>36</a>, <a href='#Page_346'>346</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Recognition, and perception, <a href='#Page_24'>24</a>, <a href='#Page_25'>25</a>;</span><br />
+<span style="margin-left: 2em;">illusions of, <a href='#Page_87'>87</a>;</span><br />
+<span style="margin-left: 2em;">and memory, <a href='#Page_234'>234</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Reflection (of light), illusions connected with, <a href='#Page_73'>73</a>, <a href='#Page_83'>83</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Refraction and optical illusion, <a href='#Page_73'>73</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Relative, sensation as, <a href='#Page_64'>64</a>;</span><br />
+<span style="margin-left: 2em;">attention to magnitude and brightness as, <a href='#Page_91'>91</a>;</span><br />
+<span style="margin-left: 2em;">estimate of duration as, <a href='#Page_249'>249</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Relief, illusory perception of, <a href='#Page_75'>75</a>, <a href='#Page_96'>96</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Representation and presentation, <a href='#Page_9'>9</a>, <a href='#Page_10'>10</a>, <a href='#Page_13'>13</a>, <a href='#Page_14'>14</a>, <a href='#Page_192'>192</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Retrospection. <i>See</i> Memory.</span><br />
+<br />
+<span style="margin-left: 1em;">Ribot, T., <a href='#Page_238'>238</a>, note<a href="#Footnote_114_114" class="fnanchor">[114]</a>, <a href='#Page_290'>290</a>, note<a href="#Footnote_135_135" class="fnanchor">[135]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Richter, J.P., <a href='#Page_143'>143</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Robertson, Professor G.C., <a href='#Page_35'>35</a>, note<a href="#Footnote_14_14" class="fnanchor">[14]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Romanes, G.J., <a href='#Page_105'>105</a>, note<a href="#Footnote_52_52" class="fnanchor">[52]</a>, <a href='#Page_250'>250</a>, note<a href="#Footnote_122_122" class="fnanchor">[122]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Rousseau, <a href='#Page_280'>280</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">S.</span><br />
+<br />
+<span style="margin-left: 1em;">Savage, dream theory of, <a href='#Page_128'>128</a>;</span><br />
+<span style="margin-left: 2em;">idea of nature of, <a href='#Page_225'>225</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Scherner, C.A., <a href='#Page_140'>140</a>, <a href='#Page_149'>149</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Schopenhauer, A., <a href='#Page_145'>145</a>, <a href='#Page_342'>342</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Schroeder, H., <a href='#Page_85'>85</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Science, philosophy and, <a href='#Page_8'>8</a>, <a href='#Page_36'>36</a>, <a href='#Page_285'>285</a>, <a href='#Page_344'>344</a>;</span><br />
+<span style="margin-left: 2em;">conception of the material world in physical, <a href='#Page_36'>36</a>, <a href='#Page_343'>343</a>, <a href='#Page_346'>346</a>, <a href='#Page_347'>347</a>;</span><br />
+<span style="margin-left: 2em;">and common cognition, <a href='#Page_338'>338</a>, <a href='#Page_357'>357</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Scott, Sir W., <a href='#Page_116'>116</a>, <a href='#Page_125'>125</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Secondary qualities, <a href='#Page_36'>36</a>, <a href='#Page_344'>344</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Selection, process of, in perception, <a href='#Page_95'>95</a>;</span><br />
+<span style="margin-left: 2em;">in dreams, <a href='#Page_174'>174</a>;</span><br />
+<span style="margin-left: 2em;">in memory, <a href='#Page_257'>257</a>, <a href='#Page_263'>263</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Self, confusion of, in dreams, <a href='#Page_163'>163</a>;</span><br />
+<span style="margin-left: 2em;">introspective knowledge of, <a href='#Page_192'>192</a>;</span><br />
+<span style="margin-left: 2em;">self-deception, <a href='#Page_200'>200</a>;</span><br />
+<span style="margin-left: 2em;">identity of, <a href='#Page_241'>241</a>, <a href='#Page_282'>282</a>, <a href='#Page_285'>285</a>;</span><br />
+<span style="margin-left: 2em;">confusion of present and past, <a href='#Page_267'>267</a>, <a href='#Page_284'>284</a>;</span><br />
+<span style="margin-left: 2em;">disturbances in recognition of, <a href='#Page_287'>287</a>, <a href='#Page_289'>289</a>;</span><br />
+<span style="margin-left: 2em;">momentary confusions of, <a href='#Page_295'>295</a>;</span><br />
+<span style="margin-left: 2em;">confusion of present and future, <a href='#Page_305'>305</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Self-esteem, illusion of, <a href='#Page_315'>315</a>;</span><br />
+<span style="margin-left: 2em;">origin of, <a href='#Page_319'>319</a>;</span><br />
+<span style="margin-left: 2em;">utility of, <a href='#Page_342'>342</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Self-preservation, <a href='#Page_320'>320</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Sensation, element in perception, <a href='#Page_20'>20</a>;</span><br />
+<span style="margin-left: 2em;">discrimination and classification of, <a href='#Page_21'>21</a>;</span><br />
+<span style="margin-left: 2em;">interpretation of, <a href='#Page_22'>22</a>;</span><br />
+<span style="margin-left: 2em;">inattention to, <a href='#Page_39'>39</a>, <a href='#Page_87'>87</a>;</span><br />
+<span style="margin-left: 2em;">modified by central reaction, <a href='#Page_39'>39</a>, <a href='#Page_87'>87</a>, <a href='#Page_89'>89</a>, <a href='#Page_91'>91</a>;</span><br />
+<span style="margin-left: 2em;">confusion of novel, <a href='#Page_40'>40</a>;</span><br />
+<span style="margin-left: 2em;">indistinct, <a href='#Page_41'>41</a>;</span><br />
+<span style="margin-left: 2em;">misinterpretation of, <a href='#Page_44'>44</a>;</span><br />
+<span style="margin-left: 2em;">relation of, to stimulus, <a href='#Page_46'>46</a>, <a href='#Page_50'>50</a>;</span><br />
+<span style="margin-left: 2em;">limits to discrimination of, <a href='#Page_52'>52</a>;</span><br />
+<span style="margin-left: 2em;">after-impression, <a href='#Page_55'>55</a>;</span><br />
+<span style="margin-left: 2em;">subjective, <a href='#Page_59'>59</a>, <a href='#Page_62'>62</a>, <a href='#Page_107'>107</a>, <a href='#Page_143'>143</a>;</span><br />
+<span style="margin-left: 2em;">localization of, <a href='#Page_59'>59</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Sensibility, limits of, <a href='#Page_50'>50</a>;</span><br />
+<span style="margin-left: 2em;">variations of, <a href='#Page_64'>64</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Sensualism, philosophic, <a href='#Page_348'>348</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Shadow, cast, <a href='#Page_77'>77</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Shakespeare, <a href='#Page_3'>3</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Sight, mode of perception, <a href='#Page_19'>19</a>, <a href='#Page_33'>33</a>, <a href='#Page_34'>34</a>, <a href='#Page_48'>48</a>, <a href='#Page_49'>49</a>;</span><br />
+<span style="margin-left: 2em;">local discrimination in, <a href='#Page_52'>52</a>;</span><br />
+<span style="margin-left: 2em;">single vision, <a href='#Page_54'>54</a>;</span><br />
+<span style="margin-left: 2em;">localization of impression in, <a href='#Page_60'>60</a>;</span><br />
+<span style="margin-left: 2em;">in sleep, <a href='#Page_139'>139</a>;</span><br />
+<span style="margin-left: 2em;">images of, in sleep, <a href='#Page_150'>150</a>, <a href='#Page_154'>154</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Single, vision, <a href='#Page_54'>54</a>;</span><br />
+<span style="margin-left: 2em;">touch, <a href='#Page_72'>72</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Sleep, mystery of, <a href='#Page_127'>127</a>;</span><br />
+<span style="margin-left: 2em;">physiology of, <a href='#Page_131'>131</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Sleight of hand. <i>See</i> Conjuror.</span><br />
+<br />
+<span style="margin-left: 1em;">Smell, as mode of perception, <a href='#Page_34'>34</a>, note<a href="#Footnote_14_14" class="fnanchor">[14]</a>;</span><br />
+<span class='pagenum'><a name="Page_371" id="Page_371">[Pg 371]</a></span><br />
+<span style="margin-left: 2em;">localization of impression in, <a href='#Page_60'>60</a>;</span><br />
+<span style="margin-left: 2em;">subjective sensations of, <a href='#Page_108'>108</a>;</span><br />
+<span style="margin-left: 2em;">in sleep, <a href='#Page_141'>141</a>;</span><br />
+<span style="margin-left: 2em;">and taste, <a href='#Page_171'>171</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Solidity, illusory perception of, <a href='#Page_75'>75</a>, <a href='#Page_96'>96</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Space, representation of, <a href='#Page_207'>207</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Specific energy of nerves, <a href='#Page_58'>58</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Spectra, ocular, etc. <i>See</i> Subjective sensation.</span><br />
+<br />
+<span style="margin-left: 1em;">Spencer, Herbert, <a href='#Page_32'>32</a>, note<a href="#Footnote_12_12" class="fnanchor">[12]</a>, <a href='#Page_128'>128</a>, note<a href="#Footnote_69_69" class="fnanchor">[69]</a>, <a href='#Page_323'>323</a>, <a href='#Page_340'>340</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Spinoza, <a href='#Page_143'>143</a>, <a href='#Page_184'>184</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Spiritualist <i>s&eacute;ances</i>, <a href='#Page_103'>103</a>, <a href='#Page_107'>107</a>, <a href='#Page_123'>123</a>, <a href='#Page_265'>265</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Stereoscope, <a href='#Page_75'>75</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Stewart, Dugald, <a href='#Page_172'>172</a>, <a href='#Page_306'>306</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Stimulus, qualitative relation of, to sensations, <a href='#Page_46'>46</a>, <a href='#Page_58'>58</a>, <a href='#Page_67'>67</a>;</span><br />
+<span style="margin-left: 2em;">quantitative relation of, to sensation, <a href='#Page_50'>50</a>, <a href='#Page_64'>64</a>;</span><br />
+<span style="margin-left: 2em;">after-effect of, <a href='#Page_55'>55</a>;</span><br />
+<span style="margin-left: 2em;">prolonged action of, <a href='#Page_56'>56</a>;</span><br />
+<span style="margin-left: 2em;">subjective or internal, <a href='#Page_62'>62</a>;</span><br />
+<span style="margin-left: 2em;">exceptional relation of, to organ, <a href='#Page_70'>70</a>;</span><br />
+<span style="margin-left: 2em;">action of, in sleep, <a href='#Page_135'>135</a>, <a href='#Page_139'>139</a>, <a href='#Page_143'>143</a>;</span><br />
+<span style="margin-left: 2em;">in hypnotic condition, <a href='#Page_186'>186</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Str&uuml;mpell, L., <a href='#Page_144'>144</a>, <a href='#Page_147'>147</a>, note<a href="#Footnote_89_89" class="fnanchor">[89]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Subjective, experience, <a href='#Page_26'>26</a>, <a href='#Page_27'>27</a>, <a href='#Page_137'>137</a>, <a href='#Page_214'>214</a>;</span><br />
+<span style="margin-left: 2em;">movement, <a href='#Page_51'>51</a>, <a href='#Page_57'>57</a>;</span><br />
+<span style="margin-left: 2em;">sensation, <a href='#Page_59'>59</a>, <a href='#Page_62'>62</a>, <a href='#Page_107'>107</a>, <a href='#Page_113'>113</a>, <a href='#Page_121'>121</a>, <a href='#Page_143'>143</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Suggestion, by external circumstances, <a href='#Page_30'>30</a>, <a href='#Page_44'>44</a>, <a href='#Page_89'>89</a>, <a href='#Page_91'>91</a>, <a href='#Page_267'>267</a>;</span><br />
+<span style="margin-left: 2em;">verbal, <a href='#Page_30'>30</a>, <a href='#Page_106'>106</a>, <a href='#Page_188'>188</a>, <a href='#Page_215'>215</a>, <a href='#Page_268'>268</a>, <a href='#Page_301'>301</a>, <a href='#Page_310'>310</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Symbol, dream as, <a href='#Page_129'>129</a>, <a href='#Page_149'>149</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Sympathy, basis of knowledge, <a href='#Page_223'>223</a>;</span><br />
+<span style="margin-left: 2em;">and illusion of insight, <a href='#Page_223'>223</a>;</span><br />
+<span style="margin-left: 2em;">and illusion of memory, <a href='#Page_277'>277</a>;</span><br />
+<span style="margin-left: 2em;">and momentary illusion, <a href='#Page_293'>293</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">T.</span><br />
+<br />
+<span style="margin-left: 1em;">Taine, H., <a href='#Page_60'>60</a>, note<a href="#Footnote_29_29" class="fnanchor">[29]</a>, <a href='#Page_108'>108</a>, note<a href="#Footnote_54_54" class="fnanchor">[54]</a>,<a href='#Page_117'>117</a>, note<a href="#Footnote_59_59" class="fnanchor">[59]</a>, <a href='#Page_137'>137</a>,</span><br />
+<span style="margin-left: 2em;"><a href='#Page_298'>298</a>, note<a href="#Footnote_137_137" class="fnanchor">[137]</a>, <a href='#Page_356'>356</a>, note<a href="#Footnote_158_158" class="fnanchor">[158]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Taste, &aelig;sthetic. <i>See</i> &AElig;sthetic intuition.</span><br />
+<br />
+<span style="margin-left: 1em;">Taste, localization of impression in, <a href='#Page_60'>60</a>;</span><br />
+<span style="margin-left: 2em;">subjective sensations of, <a href='#Page_63'>63</a>;</span><br />
+<span style="margin-left: 2em;">variations in sensibility, <a href='#Page_68'>68</a>;</span><br />
+<span style="margin-left: 2em;">activity of, in sleep, <a href='#Page_141'>141</a>;</span><br />
+<span style="margin-left: 2em;">and smell, <a href='#Page_171'>171</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Temperament, a factor in sense-illusion, <a href='#Page_101'>101</a>;</span><br />
+<span style="margin-left: 2em;">in dreams, <a href='#Page_137'>137</a>;</span><br />
+<span style="margin-left: 2em;">in illusory belief, <a href='#Page_325'>325</a>;</span><br />
+<span style="margin-left: 2em;">in illusion generally, <a href='#Page_334'>334</a>, note<a href="#Footnote_149_149" class="fnanchor">[149]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Temperature, sense of, <a href='#Page_65'>65</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Tennyson, A., <a href='#Page_226'>226</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Testa, A.J., <a href='#Page_131'>131</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Testimony, of consciousness, <a href='#Page_205'>205</a>;</span><br />
+<span style="margin-left: 2em;">fallacies of, <a href='#Page_265'>265</a>;</span><br />
+<span style="margin-left: 2em;">to identity, <a href='#Page_267'>267</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Thaumatrope, <a href='#Page_56'>56</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Theatre, illusion of the, <a href='#Page_104'>104</a>, <a href='#Page_222'>222</a>;</span><br />
+<span style="margin-left: 2em;">self-deception of the actor, <a href='#Page_200'>200</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Thompson, Professor S.P., <a href='#Page_51'>51</a>, note<a href="#Footnote_17_17" class="fnanchor">[17]</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Thought, in relation to belief, <a href='#Page_326'>326</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Time, retrospective idea of, <a href='#Page_239'>239</a>, <a href='#Page_246'>246</a>, <a href='#Page_250'>250</a>;</span><br />
+<span style="margin-left: 2em;">constant error in estimate of, <a href='#Page_245'>245</a>;</span><br />
+<span style="margin-left: 2em;">subjective estimate of, <a href='#Page_249'>249</a>;</span><br />
+<span style="margin-left: 2em;">contemporaneous estimate of, <a href='#Page_250'>250</a>;</span><br />
+<span style="margin-left: 2em;">sense of, in insanity, <a href='#Page_290'>290</a>;</span><br />
+<span style="margin-left: 2em;">prospective estimate of, <a href='#Page_303'>303</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Touch, as form of perception, <a href='#Page_33'>33</a>, <a href='#Page_34'>34</a>, <a href='#Page_49'>49</a>;</span><br />
+<span style="margin-left: 2em;">local discrimination in, <a href='#Page_52'>52</a>;</span><br />
+<span style="margin-left: 2em;">subjective sensations of, <a href='#Page_62'>62</a>;</span><br />
+<span style="margin-left: 2em;">variations in sensibility of, <a href='#Page_65'>65</a>;</span><br />
+<span style="margin-left: 2em;">in sleep, <a href='#Page_141'>141</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Transformation, in perception, <a href='#Page_94'>94</a>;</span><br />
+<span style="margin-left: 2em;">of images in dreams, <a href='#Page_163'>163</a>;</span><br />
+<span style="margin-left: 2em;">in memory, <a href='#Page_262'>262</a>, <a href='#Page_267'>267</a>;</span><br />
+<span style="margin-left: 2em;">in expectation, <a href='#Page_305'>305</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Trick. <i>See</i> Conjuror.</span><br />
+<br />
+<span style="margin-left: 1em;">Tuke, Dr., <a href='#Page_110'>110</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Tylor, E.B., <a href='#Page_128'>128</a>, note<a href="#Footnote_69_69" class="fnanchor">[69]</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">U.</span><br />
+<br />
+<span style="margin-left: 1em;">Unconscious, inference, <a href='#Page_22'>22</a>, <a href='#Page_68'>68</a>, <a href='#Page_269'>269</a>, <a href='#Page_335'>335</a>, note<a href="#Footnote_150_150" class="fnanchor">[150]</a>;</span><br />
+<span style="margin-left: 2em;">mental activity, <a href='#Page_133'>133</a>, <a href='#Page_235'>235</a>;</span><br />
+<span style="margin-left: 2em;">impressions, <a href='#Page_41'>41</a>, <a href='#Page_152'>152</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Useful. <i>See</i> Beneficial.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">V.</span><br />
+<br />
+<span style="margin-left: 1em;">Vanity. <i>See</i> Self-esteem.</span><br />
+<br />
+<span style="margin-left: 1em;">Venn, J., <a href='#Page_299'>299</a>, note<a href="#Footnote_139_139" class="fnanchor">[139]</a>.</span><br />
+<span class='pagenum'><a name="Page_372" id="Page_372">[Pg 372]</a></span><br />
+<span style="margin-left: 1em;">Ventriloquism, <a href='#Page_82'>82</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Verification, of sense-impression, <a href='#Page_38'>38</a>, <a href='#Page_351'>351</a>;</span><br />
+<span style="margin-left: 2em;">of self-inspection, <a href='#Page_210'>210</a>;</span><br />
+<span style="margin-left: 2em;">of memory, <a href='#Page_291'>291</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Verisimilitude, in art, <a href='#Page_80'>80</a>, <a href='#Page_88'>88</a>;</span><br />
+<span style="margin-left: 2em;">in theatrical representation, <a href='#Page_104'>104</a>;</span><br />
+<span style="margin-left: 2em;">in dreams, <a href='#Page_168'>168</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Vierordt, <a href='#Page_245'>245</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Vision. <i>See</i> Sight.</span><br />
+<br />
+<span style="margin-left: 1em;">Visions, <a href='#Page_1'>1</a>, <a href='#Page_110'>110</a>;</span><br />
+<span style="margin-left: 2em;">dreams regarded as, <a href='#Page_128'>128</a>, <a href='#Page_131'>131</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Vital sense. <i>See</i> C&oelig;n&aelig;sthesis.</span><br />
+<br />
+<span style="margin-left: 1em;">Voice, internal, <a href='#Page_119'>119</a>, <a href='#Page_194'>194</a>;</span><br />
+<span style="margin-left: 2em;">activity of, in dreams, <a href='#Page_155'>155</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Volition, and perception, <a href='#Page_95'>95</a>;</span><br />
+<span style="margin-left: 2em;">absence of, during sleep, <a href='#Page_137'>137</a>,<a href='#Page_172'>172</a>;</span><br />
+<span style="margin-left: 2em;">co-operation of, in correction, of illusion, <a href='#Page_352'>352</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Volkelt, J., <a href='#Page_172'>172</a>.</span><br />
+<br />
+<br />
+<span style="margin-left: 1em;">W.</span><br />
+<br />
+<span style="margin-left: 1em;">Weber, E.H., <a href='#Page_43'>43</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Weinhold, Professor, <a href='#Page_186'>186</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Wetness, perception of, <a href='#Page_53'>53</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Wheatstone, Sir C, <a href='#Page_75'>75</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Wheel of life, <a href='#Page_56'>56</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Will. <i>See</i> Volition.</span><br />
+<br />
+<span style="margin-left: 1em;">Wordsworth, W., <a href='#Page_281'>281</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">World, our estimate of, <a href='#Page_323'>323</a>, <a href='#Page_326'>326</a>, <a href='#Page_327'>327</a>;</span><br />
+<span style="margin-left: 2em;">scientific conception of material, <a href='#Page_8'>8</a>, <a href='#Page_36'>36</a>, <a href='#Page_343'>343</a>, <a href='#Page_344'>344</a>;</span><br />
+<span style="margin-left: 2em;">reality of external, <a href='#Page_344'>344-346</a>, <a href='#Page_349'>349</a>, <a href='#Page_353'>353</a>, <a href='#Page_355'>355</a>, <a href='#Page_360'>360</a>.</span><br />
+<br />
+<span style="margin-left: 1em;">Wundt, Professor, W. <a href='#Page_13'>13</a>, note<a href="#Footnote_2_2" class="fnanchor">[2]</a>, <a href='#Page_31'>31</a>, note<a href="#Footnote_11_11" class="fnanchor">[11]</a>, <a href='#Page_32'>32</a>, note<a href="#Footnote_12_12" class="fnanchor">[12]</a>, <a href='#Page_58'>58</a>, note<a href="#Footnote_27_27" class="fnanchor">[27]</a>,</span><br />
+<span style="margin-left: 2em;"><a href='#Page_67'>67</a>, note<a href="#Footnote_34_34" class="fnanchor">[34]</a>, <a href='#Page_75'>75</a>, <a href='#Page_93'>93</a>, note<a href="#Footnote_47_47" class="fnanchor">[47]</a>, <a href='#Page_118'>118</a>, note<a href="#Footnote_63_63" class="fnanchor">[63]</a>, <a href='#Page_136'>136</a>, note<a href="#Footnote_77_77" class="fnanchor">[77]</a>, <a href='#Page_139'>139</a>, <a href='#Page_143'>143</a>,</span><br />
+<span style="margin-left: 2em;"><a href='#Page_177'>177</a>, <a href='#Page_246'>246</a>, <a href='#Page_247'>247</a>, note<a href="#Footnote_119_119" class="fnanchor">[119]</a>, <a href='#Page_251'>251</a>, <a href='#Page_252'>252</a>, <a href='#Page_254'>254</a>.</span><br />
+</p>
+
+
+<h4>THE END</h4>
+<p><br /><br /></p>
+
+<div class="footnotes"><h3>FOOTNOTES:</h3>
+
+<div class="footnote"><p><a name="Footnote_1_1" id="Footnote_1_1"></a><a href="#FNanchor_1_1"><span class="label">[1]</span></a> A history of the distinction is given by Brierre de
+Boismont, in his work <i>On Illusions</i> (translated by R. T. Hulme, 1859).
+He says that Arnold (1806) first defined hallucination, and
+distinguished it from illusion. Esquirol, in his work, <i>Des Maladies
+Mentales</i> (1838), may be said to have fixed the distinction. (See Hunt's
+translation, 1845, p. 111.)</p></div>
+
+<div class="footnote"><p><a name="Footnote_2_2" id="Footnote_2_2"></a><a href="#FNanchor_2_2"><span class="label">[2]</span></a> This fact has been fully recognized by writers on the
+pathology of the subject; for example, Griesinger, <i>Mental Pathology and
+Therapeutics</i> (London, 1867), p. 84; Baillarger, article, "Des
+Hallucinations," in the <i>M&eacute;moires de l'Acad&eacute;mie Royale de M&eacute;decine</i>,
+tom. xii. p. 273, etc; Wundt, <i>Physiologische Psychologie</i>, p. 653.</p></div>
+
+<div class="footnote"><p><a name="Footnote_3_3" id="Footnote_3_3"></a><a href="#FNanchor_3_3"><span class="label">[3]</span></a> I here touch on the distinction between the psychological
+and the philosophical view of perception, to be brought out more fully
+by-and-by.</p></div>
+
+<div class="footnote"><p><a name="Footnote_4_4" id="Footnote_4_4"></a><a href="#FNanchor_4_4"><span class="label">[4]</span></a> It might even be urged that the order here adopted is
+scientifically the best, since sense-perception is the earliest form of
+knowledge, introspected facts being known only in relation to perceived
+facts. But if the mind's knowledge of its own states is thus later in
+time, it is earlier in the logical order, that is to say, it is the most
+strictly presentative form of knowledge.</p></div>
+
+<div class="footnote"><p><a name="Footnote_5_5" id="Footnote_5_5"></a><a href="#FNanchor_5_5"><span class="label">[5]</span></a> Here and elsewhere I use the word "impression" for the
+whole complex of sensation which is present at the moment. It may,
+perhaps, not be unnecessary to add that, in employing this term, I am
+making no assumption about the independent existence of external
+objects.</p></div>
+
+<div class="footnote"><p><a name="Footnote_6_6" id="Footnote_6_6"></a><a href="#FNanchor_6_6"><span class="label">[6]</span></a> Psychological usage has now pretty well substituted the
+term "image" for "idea," in order to indicate an individual (as
+distinguished from a general) representation of a sensation or percept.
+It might, perhaps, be desirable to go further in this process of
+differentiating language, and to distinguish between a sensational
+image, <i>e.g.</i> the representation of a colour, and a perceptional image,
+as the representation of a coloured object. It may be well to add that,
+in speaking of a fusion of an image and a sensation, I do not mean that
+the former exists apart for a single instant. The term "fusion" is used
+figuratively to describe the union of the two sides or aspects of a
+complete percept.</p></div>
+
+<div class="footnote"><p><a name="Footnote_7_7" id="Footnote_7_7"></a><a href="#FNanchor_7_7"><span class="label">[7]</span></a> This impulse to fill in visual elements not actually
+present is strikingly illustrated in people's difficulty in recognizing
+the gap in the field of vision answering to the insensitive "blind" spot
+on the retina. (See Helmholtz, <i>Physiologische Optik</i>, p. 573, <i>et
+seq.</i>)</p></div>
+
+<div class="footnote"><p><a name="Footnote_8_8" id="Footnote_8_8"></a><a href="#FNanchor_8_8"><span class="label">[8]</span></a> This relation will be more fully discussed under the head
+of "Memory."</p></div>
+
+<div class="footnote"><p><a name="Footnote_9_9" id="Footnote_9_9"></a><a href="#FNanchor_9_9"><span class="label">[9]</span></a> I adopt this distinction from Dr. J. Hughlings Jackson. See
+his articles, "On Affections of Speech from Diseases of the Brain," in
+<i>Brain</i>, Nos. iii. and vii. The second stage might conveniently be named
+apperception, but for the special philosophical associations of the
+term: <i>Problems of Life and Mind</i>, third series, p. 107. This writer
+employs the word "preperception" to denote this effect of previous
+perception.</p></div>
+
+<div class="footnote"><p><a name="Footnote_10_10" id="Footnote_10_10"></a><a href="#FNanchor_10_10"><span class="label">[10]</span></a> Such verbal suggestion, moreover, acting through a
+sense-impression, has something of that vividness of effect which
+belongs to all excitation of mental images by external stimuli.</p></div>
+
+<div class="footnote"><p><a name="Footnote_11_11" id="Footnote_11_11"></a><a href="#FNanchor_11_11"><span class="label">[11]</span></a> See Wundt, <i>Physiologische Psychologie</i>, p. 723.</p></div>
+
+<div class="footnote"><p><a name="Footnote_12_12" id="Footnote_12_12"></a><a href="#FNanchor_12_12"><span class="label">[12]</span></a> For a confirmation of the view adopted in the text, see
+Professor Bain, <i>The Senses and the Intellect</i>, Part II. ch. i. sec. 8;
+Herbert Spencer, <i>Principles of Psychology</i>, vol. i. p. 234, <i>et
+passim</i>; Dr. Ferrier, <i>The Functions of the Brain</i>, p. 258, <i>et seq.</i>;
+Professor Wundt, <i>op. cit.</i>, pp. 644, 645; G. H. Lowes, <i>Problems of
+Life and Mind</i>, vol. v. p. 445, <i>et seq.</i> For an opposite view, see Dr.
+Carpenter, <i>Mental Physiology</i>, fourth edit., p. 220, etc.; Dr.
+Maudsley, <i>The Physiology of Mind</i>, ch. v. p. 259, etc.</p></div>
+
+<div class="footnote"><p><a name="Footnote_13_13" id="Footnote_13_13"></a><a href="#FNanchor_13_13"><span class="label">[13]</span></a> See note, p. 22.</p></div>
+
+<div class="footnote"><p><a name="Footnote_14_14" id="Footnote_14_14"></a><a href="#FNanchor_14_14"><span class="label">[14]</span></a> Touch gives much by way of interpretation only when an
+individual object, for example a man's hat, is recognized by aid of this
+sense alone, in which case the perception distinctly involves the
+reproduction of a complete visual percept. I may add that the organ of
+smell comes next to that of hearing, with respect both to the range and
+definiteness of its simultaneous sensations, and to the amount of
+information furnished by these. A rough sense of distance as well as of
+direction is clearly obtainable by means of this organ. There seems to
+me no reason why an animal endowed with fine olfactory sensibility, and
+capable of an analytic separation of sense elements, should not gain a
+rough perception of an external order much more complete than our
+auditory perception, which is necessarily so fragmentary. This
+supposition appears, indeed, to be the necessary complement to the idea
+first broached, so far as I am aware, by Professor Croom Robertson, that
+to such animals, visual perception consists in a reference to a system
+of muscular feelings defined and bounded by strong olfactory sensations,
+rather than by tactual sensations as in our case.</p></div>
+
+<div class="footnote"><p><a name="Footnote_15_15" id="Footnote_15_15"></a><a href="#FNanchor_15_15"><span class="label">[15]</span></a> It may be said, perhaps, that the exceptional direction of
+attention, by giving an unusual intensity to the impression, causes us
+to exaggerate it just as in the case of a novel sensation. An effort of
+attention directed to any of our vague bodily sensations easily leads us
+to magnify its cause. A similar confusion may arise even in direct
+vision, when the objects are looked at in a dim light, through a want of
+proper accommodation. (See Sir D. Brewster, <i>op. cit.</i>, letter i)</p></div>
+
+<div class="footnote"><p><a name="Footnote_16_16" id="Footnote_16_16"></a><a href="#FNanchor_16_16"><span class="label">[16]</span></a> They might also be distinguished as objective and
+subjective illusions, or as illusions <i>a posteriori</i> and illusions <i>a
+priori</i>.</p></div>
+
+<div class="footnote"><p><a name="Footnote_17_17" id="Footnote_17_17"></a><a href="#FNanchor_17_17"><span class="label">[17]</span></a> <i>Die Schein-Bewegungen</i>, von Professor Dr. J.I. Hoppe
+(1879); <i>cf.</i> an ingenious article on "Optical Illusions of Motion," by
+Professor Silvanus P. Thompson, in <i>Brain</i>, October, 1880. These
+illusions frequently involve the co-operation of some preconception or
+expectation. For example, the apparent movement of a train when we are
+watching it and expecting it to move, involves both an element of
+sense-impression and of imagination. It is possible that the illusion of
+table-turning rests on the same basis, the table-turner being unaware of
+the fact of exerting a certain amount of muscular force, and vividly
+expecting a movement of the object.</p></div>
+
+<div class="footnote"><p><a name="Footnote_18_18" id="Footnote_18_18"></a><a href="#FNanchor_18_18"><span class="label">[18]</span></a> <i>Physiologische Optik</i>, p. 316.</p></div>
+
+<div class="footnote"><p><a name="Footnote_19_19" id="Footnote_19_19"></a><a href="#FNanchor_19_19"><span class="label">[19]</span></a> It is plain that this supposed error could only be brought
+under our definition of illusion by extending the latter, so as to
+include sense-perceptions which are contradicted by reason employing
+idealized elements of sense-impression, which, as Lewes has shown
+(<i>Problems of Life and Mind</i>, i. p. 260), make up the "extra-sensible
+world" of science.</p></div>
+
+<div class="footnote"><p><a name="Footnote_20_20" id="Footnote_20_20"></a><a href="#FNanchor_20_20"><span class="label">[20]</span></a> An ingenious writer, M. Binet, has tried to prove that the
+fusion of homogeneous sensations, having little difference of local
+colour, is an illustration of this principle. (See the <i>Revue
+Philosophique</i>, September, 1880.)</p></div>
+
+<div class="footnote"><p><a name="Footnote_21_21" id="Footnote_21_21"></a><a href="#FNanchor_21_21"><span class="label">[21]</span></a> Even the fusion of elementary sensations of colour, on the
+hypothesis of Young and Helmholtz, in a seemingly simple sensation may
+be explained to some extent by these circumstances, more especially the
+identity of local interpretation.</p></div>
+
+<div class="footnote"><p><a name="Footnote_22_22" id="Footnote_22_22"></a><a href="#FNanchor_22_22"><span class="label">[22]</span></a> The perception of lustre as a single quality seems to
+illustrate a like error. There is good reason to suppose that this
+impression arises through, a difference of brightness in the two retinal
+images due to the regularly reflected light. And so when this inequality
+of retinal impression is imitated, as it may easily be by combining a
+black and a white surface in a stereoscope, we imagine that we are
+looking at one lustrous surface. (See Helmholtz, <i>Physiologische Optik</i>,
+p. 782, etc., and <i>Popul&auml;re wissenschaftliche Vortr&auml;ge</i>, 2tes Heft, p.
+80.)</p></div>
+
+<div class="footnote"><p><a name="Footnote_23_23" id="Footnote_23_23"></a><a href="#FNanchor_23_23"><span class="label">[23]</span></a> The conditions of the production of these double images
+have been accurately determined by Helmholtz, who shows that the
+coalescence of impressions takes place whenever the object is so
+situated in the field of vision as to make it practically necessary that
+it should be recognized as one.</p></div>
+
+<div class="footnote"><p><a name="Footnote_24_24" id="Footnote_24_24"></a><a href="#FNanchor_24_24"><span class="label">[24]</span></a> These illusions are, of course, due in part to
+inattention, since close critical scrutiny is often sufficient to dispel
+them. They are also largely promoted by a preconception that the event
+is going to happen in a particular way. But of this more further on. I
+may add that the late Professor Clifford has argued ingeniously against
+the idea of the world being a continuum, by extending this idea of the
+wheel of life. (See <i>Lectures and Essays</i>, i. p. 112, <i>et seq.</i>)</p></div>
+
+<div class="footnote"><p><a name="Footnote_25_25" id="Footnote_25_25"></a><a href="#FNanchor_25_25"><span class="label">[25]</span></a> It is supposed that in the case of every sense-organ there
+is always some minimum forces of stimulus at work, the effect of which
+on our consciousness is <i>nil</i>.</p></div>
+
+<div class="footnote"><p><a name="Footnote_26_26" id="Footnote_26_26"></a><a href="#FNanchor_26_26"><span class="label">[26]</span></a> See Helmholtz, <i>Physiologische Optik</i>, p. 603. Helmholtz's
+explanation is criticised by Dr. Hoppe, in the work already referred to
+(sec. vii), though I cannot see that his own theory of these movements
+is essentially different. The apparent movement of objects in vertigo,
+or giddiness, is probably due to the loss, through a physical cause, of
+the impressions made by the pressure of the fluid contents of the ear on
+the auditory fibres, by which the sense of equilibrium and of rotation
+is usually received. (See Ferrier, <i>Functions of the Brain</i>, pp. 60,
+61.)</p></div>
+
+<div class="footnote"><p><a name="Footnote_27_27" id="Footnote_27_27"></a><a href="#FNanchor_27_27"><span class="label">[27]</span></a> I do not need here to go into the question whether, as
+Johannes M&uuml;ller assumed, this is an original attribute of
+nerve-structure, or whether, as Wundt suggests, it is due simply to the
+fact that certain kinds of nervous fibre have, in the course of
+evolution, been slowly adapted to one kind of stimulus.</p></div>
+
+<div class="footnote"><p><a name="Footnote_28_28" id="Footnote_28_28"></a><a href="#FNanchor_28_28"><span class="label">[28]</span></a> I here refer to what is commonly supposed to be the vague
+innate difference of sensation according to the local origin, before
+this is rendered precise, and added to by experience and association.</p></div>
+
+<div class="footnote"><p><a name="Footnote_29_29" id="Footnote_29_29"></a><a href="#FNanchor_29_29"><span class="label">[29]</span></a> The illusory character of this simple mode of perception
+is seen best, perhaps, in the curious habit into which we fall of
+referring a sensation of contact or discomfort to the edge of the teeth,
+the hair, and the other insentient structures, and even to anything
+customarily attached to the sentient surface, as dress, a pen, graving
+tool, etc. On these curious illusions, see Lotze, <i>Mikrokosmus</i>, third
+edit., vol. ii. p. 202, etc.; Taine, <i>De l'Intelligence</i>, tom. ii. p.
+83, <i>et seq.</i></p></div>
+
+<div class="footnote"><p><a name="Footnote_30_30" id="Footnote_30_30"></a><a href="#FNanchor_30_30"><span class="label">[30]</span></a> Quoted by G.H. Lewes, <i>Problems of Life and Mind</i>, third
+series, p. 335. These illusions are supposed to involve an excitation of
+the nerve-fibres (whether sensory or motor) which run to the muscles and
+yield the so-called muscular sensations.</p></div>
+
+<div class="footnote"><p><a name="Footnote_31_31" id="Footnote_31_31"></a><a href="#FNanchor_31_31"><span class="label">[31]</span></a> It is brought out by Griesinger (<i>loc. cit.</i>) and the
+other writers on the pathology of illusion already quoted, that in the
+case of subjective sensations of touch, taste, and smell, no sharp line
+can be drawn between illusion and hallucination.</p></div>
+
+<div class="footnote"><p><a name="Footnote_32_32" id="Footnote_32_32"></a><a href="#FNanchor_32_32"><span class="label">[32]</span></a> For a fuller account of these pathological disturbances of
+sensibility, see Griesinger; also Dr. A. Mayer, <i>Die Sinnest&auml;uschungen</i>.</p></div>
+
+<div class="footnote"><p><a name="Footnote_33_33" id="Footnote_33_33"></a><a href="#FNanchor_33_33"><span class="label">[33]</span></a> Helmholtz, <i>op. cit.</i>, p. 600, <i>et seq.</i> These facts seem
+to point to the conclusion that at least some of the feelings by which
+we know that we are expending muscular energy are connected with the
+initial stage of the outgoing nervous process in the motor centres. In
+other pathological conditions the sense of weight by the muscles of the
+arms is similarly confused.</p></div>
+
+<div class="footnote"><p><a name="Footnote_34_34" id="Footnote_34_34"></a><a href="#FNanchor_34_34"><span class="label">[34]</span></a> Wundt (<i>Physiologische Psychologie</i>, p. 653) would exclude
+from illusions all those errors of sense-perception which have their
+foundation in the normal structure and function of the organs of sense.
+Thus, he would exclude the effects of colour-contrast, <i>e.g.</i> the
+apparent modification of two colours in, juxtaposition towards their
+common boundary, which probably arises (according to E. Hering) from
+some mutual influence of the temporary state of activity of adjacent
+retinal elements. To me, however, these appear to be illusions, since
+they may be brought under the head of wrong <i>interpretations</i> of
+sense-impressions. When we see a grey patch as rose-red, as though it
+were so independently of the action of the complementary light
+previously or simultaneously, that is to say, as though it would appear
+rose-red to an eye independently of this action, we surely
+misinterpret.</p></div>
+
+<div class="footnote"><p><a name="Footnote_35_35" id="Footnote_35_35"></a><a href="#FNanchor_35_35"><span class="label">[35]</span></a> Quoted by G.H. Lewes, <i>loc. cit.</i>, p. 257.</p></div>
+
+<div class="footnote"><p><a name="Footnote_36_36" id="Footnote_36_36"></a><a href="#FNanchor_36_36"><span class="label">[36]</span></a> The subject of the perception of movement is too intricate
+to be dealt with fully here. I have only touched on it so far as
+necessary to illustrate our general principle. For a fuller treatment of
+the subject, see the work of Dr. Hoppe, already referred to.</p></div>
+
+<div class="footnote"><p><a name="Footnote_37_37" id="Footnote_37_37"></a><a href="#FNanchor_37_37"><span class="label">[37]</span></a> The perception of magnitude is closely connected with that
+of distance, and is similarly apt to take an illusory form. I need only
+refer to the well-known simple optical contrivances for increasing the
+apparent magnitude of objects. I ought, perhaps, to add that I do not
+profess to give a complete account of optical illusions here, but only
+to select a few prominent varieties, with a view to illustrate general
+principles of illusion. For a fuller account of the various mechanical
+arrangements for producing optical illusion, I must refer the reader to
+the writings of Sir D. Brewster and Helmholtz.</p></div>
+
+<div class="footnote"><p><a name="Footnote_38_38" id="Footnote_38_38"></a><a href="#FNanchor_38_38"><span class="label">[38]</span></a> Painters are well aware that the colours at the red end of
+the spectrum are apt to appear as advancing, while those of the violet
+end are known as retiring. The appearance of relief given by a gilded
+pattern on a dark blue as ground, is in part referable to the principle
+just referred to. In addition, it appears to involve a difference in the
+action of the muscles of accommodation in the successive adaptations of
+the eye to the most refrangible and the least refrangible rays. (See
+Br&uuml;cke, <i>Die Physiologie der Farben</i>, sec. 17.)</p></div>
+
+<div class="footnote"><p><a name="Footnote_39_39" id="Footnote_39_39"></a><a href="#FNanchor_39_39"><span class="label">[39]</span></a> Helmholtz tells us (<i>Popul&auml;re wissenschaftliche Vortr&auml;ge</i>,
+3tes Heft, p. 64) that even in a stereoscopic arrangement the presence
+of a wrong cast shadow sufficed to disturb the illusion.</p></div>
+
+<div class="footnote"><p><a name="Footnote_40_40" id="Footnote_40_40"></a><a href="#FNanchor_40_40"><span class="label">[40]</span></a> Among the means of giving a vivid sense of depth to a
+picture, emphasized by Helmholtz, is diminishing magnitude. It is
+obvious that the perceptions of real magnitude and distance are mutually
+involved. When, for example, a picture represents a receding series of
+objects, as animals, trees, or buildings, the sense of the third
+dimension, is rendered much more clear.</p></div>
+
+<div class="footnote"><p><a name="Footnote_41_41" id="Footnote_41_41"></a><a href="#FNanchor_41_41"><span class="label">[41]</span></a> A striking example of this was given in a painting, by
+Andsell, of a sportsman in the act of shooting, exhibited in the Royal
+Academy in 1879.</p></div>
+
+<div class="footnote"><p><a name="Footnote_42_42" id="Footnote_42_42"></a><a href="#FNanchor_42_42"><span class="label">[42]</span></a> This is at least true of all near objects.</p></div>
+
+<div class="footnote"><p><a name="Footnote_43_43" id="Footnote_43_43"></a><a href="#FNanchor_43_43"><span class="label">[43]</span></a> Helmholtz remarks <i>(op. cit.</i>, p. 628) that the difficulty
+of seeing the convex cast as concave is probably due to the presence of
+the cast shadow. This has, no doubt, some effect: yet the consideration
+urged in the text appears to me to be the most important one.</p></div>
+
+<div class="footnote"><p><a name="Footnote_44_44" id="Footnote_44_44"></a><a href="#FNanchor_44_44"><span class="label">[44]</span></a> <i>Popul&auml;re wissenschaftliche Vortr&auml;ge</i>, 3tes Heft, pp. 71,
+72.</p></div>
+
+<div class="footnote"><p><a name="Footnote_45_45" id="Footnote_45_45"></a><a href="#FNanchor_45_45"><span class="label">[45]</span></a> See, on this point, some excellent remarks by G.H. Lewes,
+<i>Problems of Life and Mind</i>, third series, vol. ii. p. 275.</p></div>
+
+<div class="footnote"><p><a name="Footnote_46_46" id="Footnote_46_46"></a><a href="#FNanchor_46_46"><span class="label">[46]</span></a> To some extent this applies to the changes of apparent
+magnitude due to altered position. Thus, we do not attend to the
+reduction of the height of a small object which we are wont to handle,
+when it is placed far below the level of the eye. And hence the error
+people make in judging of the point in the wall or skirting which a hat
+will reach when placed on the ground.</p></div>
+
+<div class="footnote"><p><a name="Footnote_47_47" id="Footnote_47_47"></a><a href="#FNanchor_47_47"><span class="label">[47]</span></a> I refer to the experiments made by Exner, Wundt, and
+others, in determining the time elapsing between the giving of a signal
+to a person and the execution of a movement in response. "It is found,"
+says Wundt, "by these experiments that the exact moment at which a
+sense-impression is perceived depends on the amount of preparatory
+self-accommodation of attention." (See Wundt, <i>Physiologische
+Psychologie</i>, ch. xix., especially p. 735. <i>et seq.</i>)</p></div>
+
+<div class="footnote"><p><a name="Footnote_48_48" id="Footnote_48_48"></a><a href="#FNanchor_48_48"><span class="label">[48]</span></a> Quoted by Helmholtz, <i>op. cit.</i>, p. 626.</p></div>
+
+<div class="footnote"><p><a name="Footnote_49_49" id="Footnote_49_49"></a><a href="#FNanchor_49_49"><span class="label">[49]</span></a> When the drawing, by its adherence to the laws of
+perspective, does not powerfully determine the eye to see it in one way
+rather than in the other (as in Figs. 5 to 7), the disposition to see
+the one form rather than the other points to differences in the
+frequency of the original forms in our daily experience. At the same
+time, it is to be observed that, after looking at the drawing for a time
+under each aspect, the suggestion now of the one and now of the other
+forces itself on the mind in a curious and unaccountable way.</p></div>
+
+<div class="footnote"><p><a name="Footnote_50_50" id="Footnote_50_50"></a><a href="#FNanchor_50_50"><span class="label">[50]</span></a> <i>Ueber die phantastischen Gesichsterscheinungen</i>, p. 45.</p></div>
+
+<div class="footnote"><p><a name="Footnote_51_51" id="Footnote_51_51"></a><a href="#FNanchor_51_51"><span class="label">[51]</span></a> Another side of histrionic illusion, the reading of the
+imitated feelings into the actors' minds, will be dealt with in a later
+chapter.</p></div>
+
+<div class="footnote"><p><a name="Footnote_52_52" id="Footnote_52_52"></a><a href="#FNanchor_52_52"><span class="label">[52]</span></a> In a finished painting of any size this preparation is
+hardly necessary. In these cases, in spite of the great deviations from
+truth in pictorial representation already touched on, the amount of
+essential agreement is so large and so powerful in its effect that even
+an intelligent animal will experience an illusion. Mr. Romanes sends me
+an interesting account of a dog, that had never been accustomed to
+pictures, having been put into a state of great excitement by the
+introduction of a portrait into a room, on a level with his eye. It is
+not at all improbable that the lower animals, even when sane, are
+frequently the subjects of slight illusion. That animals dream is a fact
+which is observed as long ago as the age of Lucretius.</p></div>
+
+<div class="footnote"><p><a name="Footnote_53_53" id="Footnote_53_53"></a><a href="#FNanchor_53_53"><span class="label">[53]</span></a> This kind of illusion is probably facilitated by the fact
+that the eye is often performing slight movements without any clear
+consciousness of them. See what was said about the limits of
+sensibility, p. 50.</p></div>
+
+<div class="footnote"><p><a name="Footnote_54_54" id="Footnote_54_54"></a><a href="#FNanchor_54_54"><span class="label">[54]</span></a> <i>Mental Physiology</i>, fourth edit., p. 158.</p></div>
+
+<div class="footnote"><p><a name="Footnote_55_55" id="Footnote_55_55"></a><a href="#FNanchor_55_55"><span class="label">[55]</span></a> In persons of very lively imagination the mere
+representation of an object or event may suffice to bring about such a
+semblance of sensation. Thus, M. Taine (<i>op. cit.</i>, vol. i. p. 94)
+vouches for the assertion that "one of the most exact and lucid of
+modern novelists," when working out in his imagination the poisoning of
+one of his fictitious characters, had so vivid a gustatory sensation of
+arsenic that he was attacked by a violent fit of indigestion.</p></div>
+
+<div class="footnote"><p><a name="Footnote_56_56" id="Footnote_56_56"></a><a href="#FNanchor_56_56"><span class="label">[56]</span></a> Mentioned by Dr. Carpenter (<i>Mental Physiology</i>, p. 207),
+where other curious examples are to be found.</p></div>
+
+<div class="footnote"><p><a name="Footnote_57_57" id="Footnote_57_57"></a><a href="#FNanchor_57_57"><span class="label">[57]</span></a> See <i>Annales M&eacute;dico-Psychologiques</i>, tom. vi. p. 168,
+etc.; tom. vii. p. 1, etc.</p></div>
+
+<div class="footnote"><p><a name="Footnote_58_58" id="Footnote_58_58"></a><a href="#FNanchor_58_58"><span class="label">[58]</span></a> I have already touched on the resonance of a
+sense-impression when the stimulus has ceased to act (see p. 55). The
+remarks in the text hold good of all such after-impressions, in so far
+as they take the form of fully developed percepts. A good example is the
+recurrence of the images of microscopic preparations, to which the
+anatomist is liable. (See Lewes, <i>Problems of Life and Mind</i>, third
+series, vol. ii. p. 299.) Since a complete hallucination is supposed to
+involve the peripheral regions of the nerve, the mere fact of shutting
+the eye would not, it is clear, serve as a test of the origin of the
+illusion.</p></div>
+
+<div class="footnote"><p><a name="Footnote_59_59" id="Footnote_59_59"></a><a href="#FNanchor_59_59"><span class="label">[59]</span></a> That subjective sensation may become the starting-point in
+complete hallucination is shown in a curious instance given by Lazarus,
+and quoted by Taine, <i>op. cit.</i>, vol. i. p. 122, <i>et seq.</i> The German
+psychologist relates that, on one occasion in Switzerland, after gazing
+for some time on a chain of snow-peaks, he saw an apparition of an
+absent friend, looking like a corpse. He goes on to explain that this
+phantom was the product of an image of recollection which somehow
+managed to combine itself with the (positive) after-image left by the
+impression of the snow-surface.</p></div>
+
+<div class="footnote"><p><a name="Footnote_60_60" id="Footnote_60_60"></a><a href="#FNanchor_60_60"><span class="label">[60]</span></a> For an account of Mr. Galton's researches, see <i>Mind</i>, No.
+xix. Compare, however, Professor Bain's judicious observations on these
+results in the next number of <i>Mind</i>. The liability of children to take
+images for percepts, is illustrated by the experiences related in a
+curious little work, <i>Visions</i>, by E.H. Clarke, M.D. (Boston, U.S.,
+1878), pp. 17, 46, and 212.</p></div>
+
+<div class="footnote"><p><a name="Footnote_61_61" id="Footnote_61_61"></a><a href="#FNanchor_61_61"><span class="label">[61]</span></a> A common way of describing the relation of the
+hallucinatory to real objects, is to say that the former appear partly
+to cover and hide the latter.</p></div>
+
+<div class="footnote"><p><a name="Footnote_62_62" id="Footnote_62_62"></a><a href="#FNanchor_62_62"><span class="label">[62]</span></a> Griesinger remarks that the forms of the hallucinations of
+the insane rarely depend on sense-disturbances alone. Though these are
+often the starting-point, it is the whole mental complexion of the time
+which gives the direction to the imagination. The common experience of
+seeing rats and mice running about during a fit of <i>delirium tremens</i>
+very well illustrates the co-operation of peripheral impressions not
+usually attended to, and possibly magnified by the morbid state of
+sensibility of the time (in this case flying spots, <i>musc&aelig; volitantes</i>),
+with emotional conditions. (See Griesinger, <i>loc. cit.</i>, p. 96.)</p></div>
+
+<div class="footnote"><p><a name="Footnote_63_63" id="Footnote_63_63"></a><a href="#FNanchor_63_63"><span class="label">[63]</span></a> Wundt (<i>Physiologische Psychologie</i>, p. 652) tells us of
+an insane woodman who saw logs of wood on all hands in front of the real
+objects.</p></div>
+
+<div class="footnote"><p><a name="Footnote_64_64" id="Footnote_64_64"></a><a href="#FNanchor_64_64"><span class="label">[64]</span></a> It is stated by Baillarger (M&eacute;moires de l'Acad&eacute;mie Royale
+de M&eacute;dicine, tom. xii. p. 273, etc.) that while visual hallucinations
+are more frequent than auditory in healthy life, the reverse relation
+holds in disease. At the same time, Griesinger remarks (<i>loc. cit.</i>, p.
+98) that visual hallucinations are rather more common than auditory in
+disease also. This is what we should expect from the number of
+subjective sensations connected with the peripheral organ of vision. The
+greater relative frequency of auditory hallucinations in disease, if
+made out, would seem to depend on the close connection between
+articulate sounds and the higher centres of intelligence, which centres
+are naturally the first to be thrown out of working order. It is
+possible, moreover, that auditory hallucinations are quite as common as
+visual in states of comparative health, though more easily overlooked.
+Professor Huxley relates that he is liable to auditory though not to
+visual hallucinations. (See <i>Elementary Lessons in Physiology</i>, p.
+267.)</p></div>
+
+<div class="footnote"><p><a name="Footnote_65_65" id="Footnote_65_65"></a><a href="#FNanchor_65_65"><span class="label">[65]</span></a> See Baillarger, <i>M&eacute;moires de l'Acad&eacute;mie Royale de
+M&eacute;dicine</i>, tom. xii. p. 273, <i>et seq.</i></p></div>
+
+<div class="footnote"><p><a name="Footnote_66_66" id="Footnote_66_66"></a><a href="#FNanchor_66_66"><span class="label">[66]</span></a> See Baillarger, <i>Annales M&eacute;dico-Psychologiques</i>, tom. vi.
+p. 168 <i>et seq.</i>; also tom. xii. p. 273, <i>et seq.</i> Compare Griesinger,
+<i>op. cit.</i> In a curious work entitled <i>Du D&eacute;mon de Socrate</i> (Paris,
+1856), M. L&eacute;lut seeks to prove that the philosopher's admonitory voice
+was an incipient auditory hallucination symptomic of a nascent stage of
+mental alienation.</p></div>
+
+<div class="footnote"><p><a name="Footnote_67_67" id="Footnote_67_67"></a><a href="#FNanchor_67_67"><span class="label">[67]</span></a> This is well brought out by Dr. J. Hughlings Jackson, in
+the papers in <i>Brain</i>, already referred to.</p></div>
+
+<div class="footnote"><p><a name="Footnote_68_68" id="Footnote_68_68"></a><a href="#FNanchor_68_68"><span class="label">[68]</span></a> <i>Friend</i>, vol. i. p. 248. The story is referred to by Sir
+W. Scott in his <i>Demonology and Witchcraft</i>.</p></div>
+
+<div class="footnote"><p><a name="Footnote_69_69" id="Footnote_69_69"></a><a href="#FNanchor_69_69"><span class="label">[69]</span></a> See E.B. Tylor, <i>Primitive Culture</i>, ch. xi.; <i>cf</i>.
+Herbert Spencer, <i>Principles of Sociology</i>, ch. x.</p></div>
+
+<div class="footnote"><p><a name="Footnote_70_70" id="Footnote_70_70"></a><a href="#FNanchor_70_70"><span class="label">[70]</span></a> For a fuller account of the different modes of
+dream-interpretation, see my article "Dream," in the ninth edition of
+the <i>Encyclop&aelig;dia Britannica</i>.</p></div>
+
+<div class="footnote"><p><a name="Footnote_71_71" id="Footnote_71_71"></a><a href="#FNanchor_71_71"><span class="label">[71]</span></a> For a fuller account of the reaction of dreams on waking
+consciousness, see Paul Radestock, <i>Schlaf und Traum</i>. The subject is
+touched on later, under the Illusions of Memory.</p></div>
+
+<div class="footnote"><p><a name="Footnote_72_72" id="Footnote_72_72"></a><a href="#FNanchor_72_72"><span class="label">[72]</span></a> For an account of the latest physiological hypotheses as
+to the proximate cause of sleep, see Radestock, <i>op. cit.</i>, appendix.</p></div>
+
+<div class="footnote"><p><a name="Footnote_73_73" id="Footnote_73_73"></a><a href="#FNanchor_73_73"><span class="label">[73]</span></a> Plutarch, Locke, and others give instances of people who
+never dreamt. Lessing asserted of himself that he never knew what it was
+to dream.</p></div>
+
+<div class="footnote"><p><a name="Footnote_74_74" id="Footnote_74_74"></a><a href="#FNanchor_74_74"><span class="label">[74]</span></a> The error touched on here will be fully dealt with under
+Illusions of Memory.</p></div>
+
+<div class="footnote"><p><a name="Footnote_75_75" id="Footnote_75_75"></a><a href="#FNanchor_75_75"><span class="label">[75]</span></a> For a very full, fair, and thoughtful discussion of this
+whole question, see Radestock, <i>op. cit.</i>, ch. iv.</p></div>
+
+<div class="footnote"><p><a name="Footnote_76_76" id="Footnote_76_76"></a><a href="#FNanchor_76_76"><span class="label">[76]</span></a> This may be technically expressed by saying that the
+liminal intensity (Schwelle) is raised during sleep.</p></div>
+
+<div class="footnote"><p><a name="Footnote_77_77" id="Footnote_77_77"></a><a href="#FNanchor_77_77"><span class="label">[77]</span></a> See Wundt, <i>Physiologische Psychologie</i>, pp. 188-191.</p></div>
+
+<div class="footnote"><p><a name="Footnote_78_78" id="Footnote_78_78"></a><a href="#FNanchor_78_78"><span class="label">[78]</span></a> There is, indeed, sometimes an undertone of critical
+reflection, which is sufficient to produce a feeling of uncertainty and
+bewilderment, and in very rare cases to amount to a vague consciousness
+that the mental experience is a dream.</p></div>
+
+<div class="footnote"><p><a name="Footnote_79_79" id="Footnote_79_79"></a><a href="#FNanchor_79_79"><span class="label">[79]</span></a> <i>Observations on Man</i>, Part I. ch. iii, sec. 5.</p></div>
+
+<div class="footnote"><p><a name="Footnote_80_80" id="Footnote_80_80"></a><a href="#FNanchor_80_80"><span class="label">[80]</span></a> Quoted by Radestock, <i>op. cit.</i>, p. 110.</p></div>
+
+<div class="footnote"><p><a name="Footnote_81_81" id="Footnote_81_81"></a><a href="#FNanchor_81_81"><span class="label">[81]</span></a> <i>Le Sommeil et les R&ecirc;ves</i>, p. 132, <i>et seq.</i></p></div>
+
+<div class="footnote"><p><a name="Footnote_82_82" id="Footnote_82_82"></a><a href="#FNanchor_82_82"><span class="label">[82]</span></a> <i>Das Leben des Traumes</i>, p. 369. Other instances are
+related by Beattie and Abercrombie.</p></div>
+
+<div class="footnote"><p><a name="Footnote_83_83" id="Footnote_83_83"></a><a href="#FNanchor_83_83"><span class="label">[83]</span></a> <i>Le Sommeil et les R&ecirc;ves</i>, p. 42, <i>et seq.</i></p></div>
+
+<div class="footnote"><p><a name="Footnote_84_84" id="Footnote_84_84"></a><a href="#FNanchor_84_84"><span class="label">[84]</span></a> <i>Beitr&auml;ge sur Physiognosie und Heautognosie</i>, p. 256. For
+other cases see H. Meyer, <i>Physiologie der Nervenfaser</i>, p. 309; and
+Str&uuml;mpell, <i>Die Natur und Entstehung der Tr&auml;ume</i>, p. 125.</p></div>
+
+<div class="footnote"><p><a name="Footnote_85_85" id="Footnote_85_85"></a><a href="#FNanchor_85_85"><span class="label">[85]</span></a> A very clear and full account of these organic sensations,
+or common sensations, has recently appeared from the pen of A. Horwicz
+in the <i>Vierteljahrsschrift f&uuml;r wissenschaftliche Philosophie</i>, iv.
+Jahrgang 3tes Heft.</p></div>
+
+<div class="footnote"><p><a name="Footnote_86_86" id="Footnote_86_86"></a><a href="#FNanchor_86_86"><span class="label">[86]</span></a> Schopenhauer uses this hypothesis in order to account for
+the apparent reality of dream-illusions. He thinks these internal
+sensations may be transformed by the "intuitive function" of the brain
+(by means of the "forms" of space, time, etc.) into quasi-realities,
+just as well as the subjective sensations of light, sound, etc., which
+arise in the organs of sense in the absence of external stimuli. (See
+<i>Versuch &uuml;ber das Geisterschen: Werke</i>, vol. v. p. 244, <i>et seq.</i>)</p></div>
+
+<div class="footnote"><p><a name="Footnote_87_87" id="Footnote_87_87"></a><a href="#FNanchor_87_87"><span class="label">[87]</span></a> <i>Das Alpdr&uuml;cken</i>, pp. 8, 9, 27.</p></div>
+
+<div class="footnote"><p><a name="Footnote_88_88" id="Footnote_88_88"></a><a href="#FNanchor_88_88"><span class="label">[88]</span></a> It is this fact which justifies writers in assigning a
+prognostic character to dreams.</p></div>
+
+<div class="footnote"><p><a name="Footnote_89_89" id="Footnote_89_89"></a><a href="#FNanchor_89_89"><span class="label">[89]</span></a> A part of the apparent exaggeration in our
+dream-experiences may be retrospective, and due to the effect of the
+impression of wonder which they leave behind them. (See Str&uuml;mpell, <i>Die
+Natur und Entstehung der Tr&auml;ume</i>.)</p></div>
+
+<div class="footnote"><p><a name="Footnote_90_90" id="Footnote_90_90"></a><a href="#FNanchor_90_90"><span class="label">[90]</span></a> <i>Cf.</i> Radestock, <i>op. cit.</i>, pp. 131, 132.</p></div>
+
+<div class="footnote"><p><a name="Footnote_91_91" id="Footnote_91_91"></a><a href="#FNanchor_91_91"><span class="label">[91]</span></a> I was on one occasion able to observe this process going
+on in the transition from waking to sleeping. I partly fell asleep when
+suffering from toothache. Instantly the successive throbs of pain
+transformed themselves into a sequence of visible movements, which I can
+only vaguely describe as the forward strides of some menacing
+adversary.</p></div>
+
+<div class="footnote"><p><a name="Footnote_92_92" id="Footnote_92_92"></a><a href="#FNanchor_92_92"><span class="label">[92]</span></a> Even the "unconscious impressions" of waking hours, that
+is to say, those impressions which are so fugitive as to leave no
+psychical trace behind, may thus rise into the clear light of
+consciousness during sleep. Maury relates a curious dream of his own, in
+which there appeared a figure that seemed quite strange to him, though
+he afterwards found that he must have been in the habit of meeting the
+original in a street through which he was accustomed to walk (<i>loc.
+cit.</i>, p. 124).</p></div>
+
+<div class="footnote"><p><a name="Footnote_93_93" id="Footnote_93_93"></a><a href="#FNanchor_93_93"><span class="label">[93]</span></a> See p. 53.</p></div>
+
+<div class="footnote"><p><a name="Footnote_94_94" id="Footnote_94_94"></a><a href="#FNanchor_94_94"><span class="label">[94]</span></a> See Maury, <i>loc. cit.</i>, p. 146.</p></div>
+
+<div class="footnote"><p><a name="Footnote_95_95" id="Footnote_95_95"></a><a href="#FNanchor_95_95"><span class="label">[95]</span></a> See what was said respecting the influence of a dominant
+emotional agitation on the interpretation of actual sense-impressions.</p></div>
+
+<div class="footnote"><p><a name="Footnote_96_96" id="Footnote_96_96"></a><a href="#FNanchor_96_96"><span class="label">[96]</span></a> It is proved experimentally that the ear has a much closer
+organic connection with the vocal organ than the eye has. Donders found
+that the period required for responding vocally to a sound-signal is
+less than that required for responding in the same way to a
+light-signal.</p></div>
+
+<div class="footnote"><p><a name="Footnote_97_97" id="Footnote_97_97"></a><a href="#FNanchor_97_97"><span class="label">[97]</span></a> On the nature of this impulse, as illustrated in waking
+and in sleep, see the article by Delb&oelig;uf, "Le Sommeil et les
+R&ecirc;ves," in the <i>Revue Philosophique</i>, June, 1880, p. 636.</p></div>
+
+<div class="footnote"><p><a name="Footnote_98_98" id="Footnote_98_98"></a><a href="#FNanchor_98_98"><span class="label">[98]</span></a> <i>Physiologische Psychologie</i>, p. 660.</p></div>
+
+<div class="footnote"><p><a name="Footnote_99_99" id="Footnote_99_99"></a><a href="#FNanchor_99_99"><span class="label">[99]</span></a> I may, perhaps, observe, after giving two dreams which
+have to do with mathematical operations, that, though I was very fond of
+them in my college days, I have long ceased to occupy myself with these
+processes. I would add, by way of redeeming my dream-intelligence from a
+deserved charge of silliness, that I once performed a respectable
+intellectual feat when asleep. I put together the riddle, "What might a
+wooden ship say when her side was stove in? Tremendous!" (Tree-mend-us).
+I was aware of having tried to improve on the form of this pun. I am
+happy to say I am not given to punning during waking life, though I had
+a fit of it once. It strikes me that punning, consisting as it does
+essentially of overlooking sense and attending to sound, is just such a
+debased kind of intellectual activity as one might look for in sleep.</p></div>
+
+<div class="footnote"><p><a name="Footnote_100_100" id="Footnote_100_100"></a><a href="#FNanchor_100_100"><span class="label">[100]</span></a> See Radestock, <i>op. cit.</i>, ch. ix.; <i>Vergleichung des
+Traumes mit dem Wahnsinn</i>.</p></div>
+
+<div class="footnote"><p><a name="Footnote_101_101" id="Footnote_101_101"></a><a href="#FNanchor_101_101"><span class="label">[101]</span></a> For Spinoza's experience, given in his own words, see Mr.
+F. Pollock's <i>Spinoza</i>, p. 57; <i>cf.</i> what Wundt says on his experience,
+<i>Physiologische Psychologie</i>, p. 648, footnote 2.</p></div>
+
+<div class="footnote"><p><a name="Footnote_102_102" id="Footnote_102_102"></a><a href="#FNanchor_102_102"><span class="label">[102]</span></a> See an interesting account of "Recent Researches on
+Hypnotism," by G. Stanley Hall, in <i>Mind</i>, January, 1881.</p></div>
+
+<div class="footnote"><p><a name="Footnote_103_103" id="Footnote_103_103"></a><a href="#FNanchor_103_103"><span class="label">[103]</span></a> I need hardly observe that physiology shows that there is
+no separation of different elementary colour-sensations which are
+locally identical.</p></div>
+
+<div class="footnote"><p><a name="Footnote_104_104" id="Footnote_104_104"></a><a href="#FNanchor_104_104"><span class="label">[104]</span></a> This kind of error is, of course, common to all kinds of
+cognition, in so far as they involve comparison. Thus, the presence of
+the excitement of the emotion of wonder at the sight of an unusually
+large object, say a mountain, disposes the mind to look on it as the
+largest of its class. Such illusions come midway between presentative
+and representative illusions. They might, perhaps, be specially marked
+off as illusions of "judgment."</p></div>
+
+<div class="footnote"><p><a name="Footnote_105_105" id="Footnote_105_105"></a><a href="#FNanchor_105_105"><span class="label">[105]</span></a> So far as any mental state, though originating in a
+fusion of elements, is now unanalyzable by the best effort of attention,
+we must of course regard it in its present form as simple. This
+distinction between what is simple or complex in its present nature, and
+what is originally so, is sometimes overlooked by psychologists. Whether
+the feelings and ideas here referred to are now simple or complex,
+cannot, I think, yet be very certainly determined. To take the idea of
+space, I find that after practice I recognize the ingredient of muscular
+feeling much better than I did at first. And this exactly answers to
+Helmholtz's contention that elementary sensations as partial tones can
+be detected after practice. Such separate recognition may be said to
+depend on correct representation. On the other hand, it must be allowed
+that there is room for the intuitionist to say that the associationist
+is here reading something into the idea which does not belong to it. It
+is to be added that the illusion which the associationist commonly seeks
+to fasten on his opponent is that of confusing final with original
+simplicity. Thus, he says that, though the idea of space may now to all
+intents and purposes be simple, it was really built up out of many
+distinct elements. More will be said on the relation of questions of
+nature and genesis further on.</p></div>
+
+<div class="footnote"><p><a name="Footnote_106_106" id="Footnote_106_106"></a><a href="#FNanchor_106_106"><span class="label">[106]</span></a> I may as well be frank and say that I myself, assuming
+free-will to be an illusion, have tried to trace the various threads of
+influence which have contributed to its remarkable vitality. (See
+<i>Sensation and Intuition</i>, ch. v., "The Genesis of the Free-Will
+Doctrine.")</p></div>
+
+<div class="footnote"><p><a name="Footnote_107_107" id="Footnote_107_107"></a><a href="#FNanchor_107_107"><span class="label">[107]</span></a> I purposely leave aside here the philosophical question,
+whether the knowledge of others' feelings is intuitive in the sense of
+being altogether independent of experience, and the manifestation of a
+fundamental belief. The inherited power referred to in the text might,
+of course, be viewed as a transmitted result of ancestral experience.</p></div>
+
+<div class="footnote"><p><a name="Footnote_108_108" id="Footnote_108_108"></a><a href="#FNanchor_108_108"><span class="label">[108]</span></a> I here assume, along with G.H. Lewes and other competent
+dramatic critics, that the actor does not and dares not feel what he
+expresses, at least not in the perfectly spontaneous way, and in the
+same measure in which he appears to feel it.</p></div>
+
+<div class="footnote"><p><a name="Footnote_109_109" id="Footnote_109_109"></a><a href="#FNanchor_109_109"><span class="label">[109]</span></a> The illusory nature of much of this emotional
+interpretation of music has been ably exposed by Mr. Gurney. (See <i>The
+Power of Sound</i>, p. 345, <i>et seq.</i>)</p></div>
+
+<div class="footnote"><p><a name="Footnote_110_110" id="Footnote_110_110"></a><a href="#FNanchor_110_110"><span class="label">[110]</span></a> The reader will note that this impulse is complementary
+to the other impulse to view all mental states as analogous to
+impressions produced by external things, on which I touched in the last
+chapter.</p></div>
+
+<div class="footnote"><p><a name="Footnote_111_111" id="Footnote_111_111"></a><a href="#FNanchor_111_111"><span class="label">[111]</span></a> Errors of memory have sometimes been called "fallacies,"
+as, for example, by Dr. Carpenter (<i>Human Physiology</i>, ch. x.). While
+preferring the term "illusion," I would not forget to acknowledge my
+indebtedness to Dr. Carpenter, who first set me seriously to consider
+the subject of mnemonic error.</p></div>
+
+<div class="footnote"><p><a name="Footnote_112_112" id="Footnote_112_112"></a><a href="#FNanchor_112_112"><span class="label">[112]</span></a> From this it would appear to follow that, so far as a
+percept is representative, recollection must be re-representative.</p></div>
+
+<div class="footnote"><p><a name="Footnote_113_113" id="Footnote_113_113"></a><a href="#FNanchor_113_113"><span class="label">[113]</span></a> The relation of memory to recognition is very well
+discussed by M. Delb&oelig;uf, in connection with a definition of memory
+given by Descartes. (See the article "Le Sommeil et les R&ecirc;ves," in the
+<i>Revue Philosophique</i>, April, 1880, p. 428, <i>et seq.</i>)</p></div>
+
+<div class="footnote"><p><a name="Footnote_114_114" id="Footnote_114_114"></a><a href="#FNanchor_114_114"><span class="label">[114]</span></a> A very interesting account of the most recent
+physiological theory of memory is to be found in a series of articles,
+bearing the title, "La M&eacute;moire comme fait biologique," published in the
+<i>Revue Philosophique</i>, from the pen of the editor, M. Th. Ribot. (See
+especially the <i>Revue</i> of May, 1880, pp. 516, <i>et seq.</i>) M. Ribot speaks
+of the modification of particular nerve-elements as "the static base" of
+memory, and of the formation of nerve-connections by means of which the
+modified element may be re-excited to activity as "the dynamic base of
+memory" (p. 535).</p></div>
+
+<div class="footnote"><p><a name="Footnote_115_115" id="Footnote_115_115"></a><a href="#FNanchor_115_115"><span class="label">[115]</span></a> What constitutes the difference between such a
+progressive and a retrogressive movement is a point that will be
+considered by-and-by.</p></div>
+
+<div class="footnote"><p><a name="Footnote_116_116" id="Footnote_116_116"></a><a href="#FNanchor_116_116"><span class="label">[116]</span></a> It is not easy to say how far exceptional conditions may
+serve to reinstate the seemingly forgotten past. Yet the experiences of
+dreamers and of those who have been recalled to consciousness after
+partial drowning, whatever they may prove with respect to the
+revivability of remote experiences, do not lead us to imagine that the
+range of our definitely localizing memory is a wide one.</p></div>
+
+<div class="footnote"><p><a name="Footnote_117_117" id="Footnote_117_117"></a><a href="#FNanchor_117_117"><span class="label">[117]</span></a> <i>Der Zeitsinn nach Versuchen</i>, p. 36, <i>et seq.</i></p></div>
+
+<div class="footnote"><p><a name="Footnote_118_118" id="Footnote_118_118"></a><a href="#FNanchor_118_118"><span class="label">[118]</span></a> <i>Physiologische Psychologie</i>, p. 782.</p></div>
+
+<div class="footnote"><p><a name="Footnote_119_119" id="Footnote_119_119"></a><a href="#FNanchor_119_119"><span class="label">[119]</span></a> Wundt refers these errors to variations in the state of
+preadjustment of the attention to impressions and representations,
+according as they succeed one another slowly or rapidly. There is little
+doubt that the effects of the state of tension of the apparatus of
+attention, are involved here, though I am disposed to think that Wundt
+makes too much of this circumstance. (See <i>Physiologische Psychologie</i>,
+pp. 782, 783. I have given a fuller account of Wundt's theory in <i>Mind</i>,
+No. i.)</p></div>
+
+<div class="footnote"><p><a name="Footnote_120_120" id="Footnote_120_120"></a><a href="#FNanchor_120_120"><span class="label">[120]</span></a> Strictly speaking, it would occupy more time, since the
+effort of recalling each successive link in the chain would involve a
+greater interval between any two images than that between the
+corresponding experiences.</p></div>
+
+<div class="footnote"><p><a name="Footnote_121_121" id="Footnote_121_121"></a><a href="#FNanchor_121_121"><span class="label">[121]</span></a> I need hardly say that there is no sharp distinction
+between these two modes of subjective appreciation. Our estimate of an
+interval as it passes is really made up of a number of renewed
+anticipations and recollections of the successive experiences. Yet we
+can say broadly that this is a prospective estimate, while that which is
+formed when the period has quite expired must be altogether
+retrospective.</p></div>
+
+<div class="footnote"><p><a name="Footnote_122_122" id="Footnote_122_122"></a><a href="#FNanchor_122_122"><span class="label">[122]</span></a> See an interesting paper on "Consciousness of Time," by
+Mr. G. J. Romanes, in <i>Mind</i> (July, 1878).</p></div>
+
+<div class="footnote"><p><a name="Footnote_123_123" id="Footnote_123_123"></a><a href="#FNanchor_123_123"><span class="label">[123]</span></a> It is well known that there is, from the first, a gradual
+falling off in the strength of a sensation of light when a moderately
+bright object is looked at.</p></div>
+
+<div class="footnote"><p><a name="Footnote_124_124" id="Footnote_124_124"></a><a href="#FNanchor_124_124"><span class="label">[124]</span></a> <i>Cf.</i> Hartley, <i>Observations on Man</i>, Part I. ch. iii.
+sec. 4 (fifth edit., p. 391).</p></div>
+
+<div class="footnote"><p><a name="Footnote_125_125" id="Footnote_125_125"></a><a href="#FNanchor_125_125"><span class="label">[125]</span></a> See Dr. Carpenter's <i>Mental Physiology</i>, fourth edit, p.
+456.</p></div>
+
+<div class="footnote"><p><a name="Footnote_126_126" id="Footnote_126_126"></a><a href="#FNanchor_126_126"><span class="label">[126]</span></a> This is, perhaps, what is meant by saying that people
+recall their past enjoyments more readily than their sufferings. Yet
+much seems to turn on temperament and emotional peculiarities. (For a
+fuller discussion of the point, see my <i>Pessimism</i>, p. 344.)</p></div>
+
+<div class="footnote"><p><a name="Footnote_127_127" id="Footnote_127_127"></a><a href="#FNanchor_127_127"><span class="label">[127]</span></a> The only exception to this that I can think of is to be
+found in the power which I, at least, possess, after looking at a new
+object, of representing it as a familiar one. Yet this may be explained
+by saying that in the case of every object which is clearly apprehended
+there must be vague revivals of <i>similar</i> objects perceived before.
+Oases in which recent experiences tend, owing to their peculiar nature,
+very rapidly to assume the appearance of old events, will be considered
+presently.</p></div>
+
+<div class="footnote"><p><a name="Footnote_128_128" id="Footnote_128_128"></a><a href="#FNanchor_128_128"><span class="label">[128]</span></a> <i>Mental Physiology</i>, p. 456.</p></div>
+
+<div class="footnote"><p><a name="Footnote_129_129" id="Footnote_129_129"></a><a href="#FNanchor_129_129"><span class="label">[129]</span></a> <i>Mental Physiology</i>, second edit., p. 172.</p></div>
+
+<div class="footnote"><p><a name="Footnote_130_130" id="Footnote_130_130"></a><a href="#FNanchor_130_130"><span class="label">[130]</span></a> <i>Loc. cit.</i>, p. 390.</p></div>
+
+<div class="footnote"><p><a name="Footnote_131_131" id="Footnote_131_131"></a><a href="#FNanchor_131_131"><span class="label">[131]</span></a> This source of error has not escaped the notice of
+autobiographers themselves. See the remarks of Goethe in the opening
+passages of his <i>Wahrheit und Dichtung</i>.</p></div>
+
+<div class="footnote"><p><a name="Footnote_132_132" id="Footnote_132_132"></a><a href="#FNanchor_132_132"><span class="label">[132]</span></a> One wonders whether those persons who, in consequence of
+an injury to their brain, periodically pass from a normal into an
+abnormal condition of mind, in each of which there is little or no
+memory of the contents of the other state, complete their idea of
+personal continuity in each state by the same kind of process as that
+described in the text.</p></div>
+
+<div class="footnote"><p><a name="Footnote_133_133" id="Footnote_133_133"></a><a href="#FNanchor_133_133"><span class="label">[133]</span></a> The reader will remark that this condition of clear
+intellectual consciousness, namely, a certain degree of similarity and
+continuity of character in our successive mental states, is
+complementary to the other condition, constant change, already referred
+to. It may, perhaps, be said that all clear consciousness lies between
+two extremes of excessive sameness and excessive difference.</p></div>
+
+<div class="footnote"><p><a name="Footnote_134_134" id="Footnote_134_134"></a><a href="#FNanchor_134_134"><span class="label">[134]</span></a> It follows that any great transformation of our
+environment may lead to a partial confusion with respect to self. For
+not only do great and violent changes in our surroundings beget profound
+changes in our feelings and ideas, but since the idea of self is under
+one of its aspects essentially that of a relation to not-self, any great
+revolution in the one term, will confuse the recognition of the other.
+This fact is expressed in the common expression that we "lose ourselves"
+when in unfamiliar surroundings, and the process of orientation, or
+"taking our bearings," fails.</p></div>
+
+<div class="footnote"><p><a name="Footnote_135_135" id="Footnote_135_135"></a><a href="#FNanchor_135_135"><span class="label">[135]</span></a> On these disturbances of memory and self-recognition in
+insanity, see Griesinger, <i>op. cit.</i>, pp. 49-51; also Ribot, "Des
+D&eacute;sordres G&eacute;n&eacute;raux de la M&eacute;moire," in the <i>Revue Philosophique</i>, August,
+1880. It is related by Leuret (<i>Fragments Psych. sur la Folie</i>, p. 277)
+that a patient spoke of his former self as "la personne de moi-m&ecirc;me."</p></div>
+
+<div class="footnote"><p><a name="Footnote_136_136" id="Footnote_136_136"></a><a href="#FNanchor_136_136"><span class="label">[136]</span></a> In the following account of the process of belief and its
+errors, I am going over some of the ground traversed by my essay on
+<i>Belief, its Varieties and Conditions</i> ("Sensation and Intuition," ch.
+iv.). To this essay I must refer the reader for a fuller analysis of the
+subject.</p></div>
+
+<div class="footnote"><p><a name="Footnote_137_137" id="Footnote_137_137"></a><a href="#FNanchor_137_137"><span class="label">[137]</span></a> For an account of the difference of mechanism in memory
+and expectation, see Taine, <i>De l'Intelligence</i>, 2i&egrave;me partie, livre
+premier, ch. ii. sec. 6.</p></div>
+
+<div class="footnote"><p><a name="Footnote_138_138" id="Footnote_138_138"></a><a href="#FNanchor_138_138"><span class="label">[138]</span></a> J.S. Mill distinguishes expectation as a radically
+distinct mode of belief from memory, but does not bring out the contrast
+with respect to activity here emphasized (James Mill's <i>Analysis of the
+Human Mind</i>, edited by J.S. Mill, p. 411, etc.). For a fuller statement
+of my view of the relation of belief to action, as compared with that of
+Professor Bain, see my earlier work.</p></div>
+
+<div class="footnote"><p><a name="Footnote_139_139" id="Footnote_139_139"></a><a href="#FNanchor_139_139"><span class="label">[139]</span></a> For some good remarks on the logical aspects of future
+events as matters of fact, see Mr. Venn's <i>Logic of Chance</i>, ch. x.</p></div>
+
+<div class="footnote"><p><a name="Footnote_140_140" id="Footnote_140_140"></a><a href="#FNanchor_140_140"><span class="label">[140]</span></a> James Mill's <i>Analysis of the Human Mind</i>, edited by J.S.
+Mill, vol. i p. 414, <i>et seq.</i></p></div>
+
+<div class="footnote"><p><a name="Footnote_141_141" id="Footnote_141_141"></a><a href="#FNanchor_141_141"><span class="label">[141]</span></a> <i>Principles of Geology</i>, ch. iii.</p></div>
+
+<div class="footnote"><p><a name="Footnote_142_142" id="Footnote_142_142"></a><a href="#FNanchor_142_142"><span class="label">[142]</span></a> To make this rough analysis more complete, I ought,
+perhaps, to include the effect of all the errors of introspection,
+memory, and spontaneous belief, into which the person himself falls, in
+so far as they communicate themselves to others.</p></div>
+
+<div class="footnote"><p><a name="Footnote_143_143" id="Footnote_143_143"></a><a href="#FNanchor_143_143"><span class="label">[143]</span></a> In the case of a vain woman thinking herself much more
+pretty than others think her, the error is still more obviously one
+connected with a belief in objective fact.</p></div>
+
+<div class="footnote"><p><a name="Footnote_144_144" id="Footnote_144_144"></a><a href="#FNanchor_144_144"><span class="label">[144]</span></a> <i>The Study of Sociology</i>, ch. ix.</p></div>
+
+<div class="footnote"><p><a name="Footnote_145_145" id="Footnote_145_145"></a><a href="#FNanchor_145_145"><span class="label">[145]</span></a> As a matter of fact, the proportion of accurate knowledge
+to error is far larger in the case of classes than of individuals.
+Propositions with general terms for subject are less liable to be faulty
+than propositions with singular terms for subject.</p></div>
+
+<div class="footnote"><p><a name="Footnote_146_146" id="Footnote_146_146"></a><a href="#FNanchor_146_146"><span class="label">[146]</span></a> For a description of each of these extremes of boundless
+gaiety and utter despondency, see Griesinger, <i>op. cit.</i>, Bk. III. ch.
+i. and ii. The relation of pessimism to pathological conditions is
+familiar enough; less familiar is the relation of unrestrained optimism.
+Yet Griesinger writes that among the insane "boundless hilarity," with
+"a feeling of good fortune," and a general contentment with everything,
+is as frequent as depression and repining (see especially p. 281, also
+pp. 64, 65).</p></div>
+
+<div class="footnote"><p><a name="Footnote_147_147" id="Footnote_147_147"></a><a href="#FNanchor_147_147"><span class="label">[147]</span></a> It has been seen that, from a purely psychological point
+of view, even what looks at first like pure presentative cognition, as,
+for example, the recognition of a present feeling of the mind, involves
+an ingredient of representation.</p></div>
+
+<div class="footnote"><p><a name="Footnote_148_148" id="Footnote_148_148"></a><a href="#FNanchor_148_148"><span class="label">[148]</span></a> See especially what was said about the <i>rationale</i> of
+illusions of perception, pp. 37, 38.</p></div>
+
+<div class="footnote"><p><a name="Footnote_149_149" id="Footnote_149_149"></a><a href="#FNanchor_149_149"><span class="label">[149]</span></a> I say "usually," because, as we have seen, there may
+sometimes be a permanent and even an inherited predisposition to active
+illusion in the individual temperament and nervous organization.</p></div>
+
+<div class="footnote"><p><a name="Footnote_150_150" id="Footnote_150_150"></a><a href="#FNanchor_150_150"><span class="label">[150]</span></a> See what was said on the nature of passive illusions of
+sense (pp. 44, 68, 70, etc.) The logical character of illusion might be
+brought out by saying that it resembles the fallacy which is due to
+reasoning from an approximate generalization as though it were a
+universal truth. In thus identifying illusion and fallacy, I must not be
+understood to say that there is, strictly speaking, any such thing as an
+unconscious reasoning process. On the contrary, I hold that it is a
+contradiction to talk of any <i>mental</i> operation as altogether
+unconscious. I simply wish to show that, by a kind of fiction, illusion
+may be described as the result of a series of steps which, if separately
+unfolded to consciousness (as they no longer are), would correspond to
+those of a process of inference. The fact that illusion arises by a
+process of contraction out of conscious inference seems to justify this
+use of language, even apart from the fact that the nervous processes in
+the two cases are pretty certainly the same.</p></div>
+
+<div class="footnote"><p><a name="Footnote_151_151" id="Footnote_151_151"></a><a href="#FNanchor_151_151"><span class="label">[151]</span></a> If we turn from the region of physical to that of moral
+ideas, we see this historical collision between common and individual
+conviction in a yet more impressive form. The teacher of a new moral
+truth has again and again been set down to be an illusionist by a
+society which was itself under the sway of a long-reigning error. As
+George Eliot observes, "What we call illusions are often, in truth, a
+wider vision of past and present realities&mdash;a willing movement of a
+man's soul with the larger sweep of the world's forces."</p></div>
+
+<div class="footnote"><p><a name="Footnote_152_152" id="Footnote_152_152"></a><a href="#FNanchor_152_152"><span class="label">[152]</span></a> To make this account of the philosophic problem of the
+object-world complete, I ought to touch not only on the distinction
+between the vulgar and the scientific view of material things, but also
+on the distinction, within physical science, between the less and the
+more abstract view roughly represented by molar and molecular physics.</p></div>
+
+<div class="footnote"><p><a name="Footnote_153_153" id="Footnote_153_153"></a><a href="#FNanchor_153_153"><span class="label">[153]</span></a> For an excellent account of the distinction between the
+scientific and the philosophic point of view, see Mr. Shadworth
+Hodgson's <i>Philosophy of Reflection</i>, Bk. I. chs. i. and iii.; also Bk.
+III. chs. vii. and viii.</p></div>
+
+<div class="footnote"><p><a name="Footnote_154_154" id="Footnote_154_154"></a><a href="#FNanchor_154_154"><span class="label">[154]</span></a> I hold, in spite of Berkeley's endeavours to reconcile
+his position with that of common sense, that the popular view does at
+least tend in this direction. That is to say, the every-day habit, when
+considering the external world, of abstracting from particular minds,
+leads on insensibly to that complete detachment of it from mind in
+general which expresses itself in the first stage of philosophic
+reflection, crude realism. The physicist appears to me, both from the
+first essays in Greek "nature-philosophy," as also from the not
+infrequent confusion even to-day between a perfectly safe "scientific
+materialism" and a highly questionable philosophic materialism, to share
+in this tendency to take separate consideration for separate existence.
+Each new stage of abstraction in physical science gives birth to a new
+attempt to find an independent reality, a thing-in-itself, hidden
+further away from sense.</p></div>
+
+<div class="footnote"><p><a name="Footnote_155_155" id="Footnote_155_155"></a><a href="#FNanchor_155_155"><span class="label">[155]</span></a> See the interesting autobiographical record of the growth
+of philosophic doubt in the <i>Premi&egrave;re M&eacute;ditation</i> of Descartes.</p></div>
+
+<div class="footnote"><p><a name="Footnote_156_156" id="Footnote_156_156"></a><a href="#FNanchor_156_156"><span class="label">[156]</span></a> The appeal is not, as we have seen, invariably from sight
+to touch, but may be in the reverse direction, as in the recognition of
+the duality of the points of a pair of compasses, which seem one to the
+tactual sense.</p></div>
+
+<div class="footnote"><p><a name="Footnote_157_157" id="Footnote_157_157"></a><a href="#FNanchor_157_157"><span class="label">[157]</span></a> I might further remark that this "collective experience"
+includes previously detected illusions of ourselves and of others.</p></div>
+
+<div class="footnote"><p><a name="Footnote_158_158" id="Footnote_158_158"></a><a href="#FNanchor_158_158"><span class="label">[158]</span></a> M. Taine frankly teaches that what is commonly called
+accurate perception is a "true hallucination" (<i>De l'Intelligence</i>,
+2i&egrave;me partie, Livre I. ch. i. sec. 3).</p></div>
+
+<div class="footnote"><p><a name="Footnote_159_159" id="Footnote_159_159"></a><a href="#FNanchor_159_159"><span class="label">[159]</span></a> It only seems to do so, apart from philosophic
+assumptions, in certain cases where experience testifies to a uniform
+untrustworthiness of the origin. For example, we may, on grounds of
+matter of fact and experience, be disposed to distrust any belief that
+we recognize as springing from an emotional source, from the mind's
+feelings and wishes.
+</p><p>
+I may add that a so-called intuitive belief may refer to a matter of
+fact which can be tested by the facts of experience and by scientific
+methods. Thus, for example, the old and now exploded form of the
+doctrine of innate ideas, which declared that children were born with
+certain ideas ready made, might be tested by observation of childhood,
+and reasoning from its general intellectual condition. The same applies
+to the physiological theories of space-perception, supposed to be based
+on Kant's doctrine, put forward in Germany by Johannes M&uuml;ller and the
+"nativistic school." (See my exposition and criticism of these doctrines
+in <i>Mind</i>, April, 1878, pp. 168-178 and 193-195.)</p></div>
+
+</div>
+
+
+
+
+
+
+
+<pre>
+
+
+
+
+
+End of the Project Gutenberg EBook of Illusions, by James Sully
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+The Project Gutenberg EBook of Illusions, by James Sully
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: Illusions
+       A Psychological Study
+
+Author: James Sully
+
+Release Date: February 21, 2006 [EBook #17815]
+
+Language: English
+
+Character set encoding: ASCII
+
+*** START OF THIS PROJECT GUTENBERG EBOOK ILLUSIONS ***
+
+
+
+
+Produced by Thierry Alberto, Janet Blenkinship and the
+Online Distributed Proofreaders Europe at
+http://dp.rastko.net
+
+
+
+
+
+
+
+
+
+  ~ILLUSIONS~
+
+  _A PSYCHOLOGICAL STUDY_
+
+
+  BY
+  JAMES SULLY
+  AUTHOR OF "SENSATION AND INTUITION," "PESSIMISM," ETC.
+
+
+  THIRD EDITION
+
+
+
+
+  LONDON
+  KEGAN PAUL, TRENCH & CO., 1, PATERNOSTER SQUARE
+  1887
+
+  (_The rights of translation and of reproduction are reserved_)
+
+
+  ~THE INTERNATIONAL SCIENTIFIC SERIES.~
+
+  VOL. XXXIV.
+
+
+
+
+PREFACE.
+
+
+The present volume takes a wide survey of the field of error, embracing
+in its view not only the illusions of sense dealt with in treatises on
+physiological optics, etc., but also other errors familiarly known as
+illusions, and resembling the former in their structure and mode of
+origin. I have throughout endeavoured to keep to a strictly scientific
+treatment, that is to say, the description and classification of
+acknowledged errors, and the explanation of these by a reference to
+their psychical and physical conditions. At the same time, I was not
+able, at the close of my exposition, to avoid pointing out how the
+psychology leads on to the philosophy of the subject. Some of the
+chapters were first roughly sketched out in articles published in
+magazines and reviews; but these have been not only greatly enlarged,
+but, to a considerable extent, rewritten.
+                                                          J. S.
+
+  _Hampstead, April, 1881._
+
+
+
+
+  CONTENTS.
+
+
+  CHAPTER I.
+
+  THE STUDY OF ILLUSION.
+
+  Vulgar idea of Illusion, 1, 2; Psychological treatment of subject,
+  3, 4; definition of Illusion, 4-7; Philosophic extension of idea,
+  7, 8.
+
+
+  CHAPTER II.
+
+  THE CLASSIFICATION OF ILLUSIONS.
+
+  Popular and Scientific conceptions of Mind, 9, 10; Illusion and
+  Hallucination, 11-13; varieties of Immediate Knowledge, 13-16; four-fold
+  division of Illusions, 16-18.
+
+
+  CHAPTER III.
+
+  ILLUSIONS OF PERCEPTION: GENERAL.
+
+  _Psychology of Perception_:--The Psychological analysis of Perception,
+   19, 20; Sensation and its discrimination, etc., 20, 21; interpretation
+   of Sensation, 22, 23; construction of material object, 23, 24;
+   recognition of object, specific and individual, 24-27; Preperception
+   and Perception, 27-31; Physiological conditions of Perception, 31-33;
+   Visual and other Sense-perception, 33, 34.
+
+  _Illusions of Perception_:--Illusion of Perception defined, 35-38;
+   sources of Sense-illusion, 38-40: (a) confusion of
+   Sense-impression, 40-44; (b) misinterpretation of Sense-impression, 44;
+   Passive and Active misinterpretation, 44-46; Passive Illusions as
+   organically and extra-organically conditioned, 46-49.
+
+
+  CHAPTER IV.
+
+  ILLUSIONS OF PERCEPTION--_continued_.
+
+  A. _Passive Illusions (a) as determined by the Organism._
+  _Results of Limits of Sensibility_:--Relation of quantity of Sensation to
+  that of Stimulus, 50-52; coalescence of simultaneous Sensations,
+  52-55; after-effect of Stimulation, 55, 56; effects of prolonged
+  Stimulation, 56-58; Specific Energy of Nerves, 58, 59; localization
+  of Sensation, 59-62; Subjective Sensations, 62-64.
+
+  _Results of Variation of Sensibility_:--Rise and fall of Sensibility,
+  64-67; Paraesesthesia, 67, 68; _rationale_ of organically conditioned
+  Illusions, 68, 69.
+
+
+  CHAPTER V.
+
+  ILLUSIONS OF PERCEPTION--_continued_.
+
+  A. _Passive Illusions (b) as determined by the Environment._
+  _Exceptional Relation of Stimulus to Organ_:--Displacement of organ,
+  etc., 70-72.
+
+  _Exceptional Arrangement of Circumstances in the Environment_:--
+  Misinterpretation of the direction and movement of objects, 72-75;
+  misperception of Distance, 75, 76; Illusions of depth, relief, and
+  solidity in Art, 77-81; Illusions connected with the perception of
+  objects through transparent coloured media, 82-84; visual transformation
+  of concave into convex form, 84-86; false recognition of
+  objects, 86, 87; inattention to Sense-impression in Recognition,
+  87-91; suggestion taking the direction of familiar recurring experiences,
+  91, 92.
+
+
+  CHAPTER VI.
+
+  ILLUSIONS OF PERCEPTION--_continued_.
+
+  B. _Active Illusions._
+
+  Preperception and Illusion, 93-95.
+
+  _Voluntary Preperception_:--Choice of interpretation in the case of
+  visible movement, 95, 96; and in the case of flat projections of form,
+  96-98; capricious interpretation of obscure impressions, 99, 100.
+
+  _Involuntary Preperception_:--Effects of permanent Predisposition,
+  101, 102; effects of partial temporary Preadjustment, 102-105;
+  complete Pro-adjustment or Expectation, 106-109; subordination of
+  Sense-impression to Preperception, 109-111; transition from Illusion
+  to Hallucination, 111, 112; rudimentary Hallucinations, 112-114;
+  developed Hallucinations, 114-116; Hallucination in normal life,
+  116, 117; Hallucinations of insanity, 118-120; gradual development
+  of Sense-illusions, and continuity of normal and abnormal life; 120-123;
+  Sanity and Insanity distinguished, 123-126.
+
+
+  CHAPTER VII.
+
+  DREAMS.
+
+  Mystery of sleep, 127, 128; theories of Dreams, 128, 129; scientific
+  explanation of Dreams, 129, 130.
+
+  _Sleep and Dreaming_:--Condition of organism during sleep, 131, 132;
+  Are the nervous centres ever wholly inactive during sleep? 132-134;
+  nature of cerebral activity involved in Dreams, 134-136; psychical
+  conditions of Dreams, 136-138.
+
+  _The Dream as Illusion_:--External Sense-impressions as excitants of
+  Dream-images, 139-143; internal "subjective" stimuli in the sense-organs,
+  143-145; organic sensations, 145-147; how sensations are
+  exaggerated in Dream-interpretation, 147-151.
+
+  _The Dream as Hallucination_:--Results of direct central stimulation
+  151-153; indirect central stimulation and association, 153-155.
+
+  _The Form and Structure of Dreams_:--The incoherence of Dreams explained,
+  156-161; coherence and unity of Dream as effected (a) by
+  coalescence and transformation of images, 161-163; (b) by aground-tone
+  of feeling, 164-168; (c) by the play of associative dispositions,
+  168-172; (d) by the activities of selective attention stimulated by
+  the rational impulse to connect and to arrange, 172-176; examples
+  of Dreams, 176-179; limits of intelligence and rational activity in
+  Dreams, 180-182; Dreaming and mental disease, 182, 183; After-dreams
+  and Apparitions, 183-185.
+
+  NOTE.--The Hypnotic Condition, 185-188.
+
+
+  CHAPTER VIII.
+
+  ILLUSIONS OF INTROSPECTION.
+
+  Illusions of Introspection defined, 189-192; question of the possibility
+  of illusory Introspection, 192-194; incomplete grasp of internal
+  feelings as such, 194-196; misobservation of internal feelings: Passive
+  Illusions, 196-199; Active Illusions, 199-202; malobservation of
+  subjective states, 202-205; Illusory Introspection in psychology and
+  philosophy, 205-208; value of the Introspective method, 208-211.
+
+
+  CHAPTER IX.
+
+  OTHER QUASI-PRESENTATIVE ILLUSIONS: ERRORS OF INSIGHT.
+
+  Emotion and Perception, 212; AEsthetic Intuition, 213; Subjective
+  Impressions of beauty misinterpreted, 213-216; analogous Emotional
+  Intuitions, 216, 217; Insight, its nature, 217-220; Passive Illusions
+  of Insight, 220-222; Active Illusions of Insight: projection of
+  individual feelings, 222-224; the poetic transformation of nature,
+  224-226; special predispositions as falsifying Insight, 226-228;
+  value of faculty of Insight, 228-230.
+
+
+  CHAPTER X.
+
+  ILLUSIONS OF MEMORY.
+
+  Vulgar confidence in Memory, 231-233; definition of Memory, 233-235;
+  Psychology of Memory, 235-237; Physiology of Memory, 237, 238;
+  Memory as localization in the past, 238-241; Illusions of Memory
+  classified, 241-245.
+
+  (1) _Illusions of Time-Perspective_:--
+
+  (a) Definite Localization of events: constant errors in retrospective
+  estimate of time, 245-249; varying errors: estimate of duration
+  during a period, 249-251; variations in retrospective estimate of
+  duration, 251-256.
+
+  (b) Indefinite Localization: effect of vividness of mnemonic image
+  on the apparent distance of events, 256-258; isolated public events,
+  258, 259; active element in errors of Localization, 259-261.
+
+  (2) _Distortions of Memory_:--Transformation of past through
+  forgetfulness, 261-264; confusion of distinct recollections, 264-266;
+  Active Illusion: influence of present imaginative activity, 266-269;
+  exaggeration in recollections of remote experiences, 269, 270; action of
+  present feeling in transforming past, 270, 271.
+
+  (3) _Hallucinations of Memory_:--Their nature, 271-273; past dreams taken
+  for external experiences, 273-277; past waking imagination taken
+  for external reality, 277-280; recollection of prenatal ancestral
+  experience, 280, 281; filling up gaps in recollection, 281-283.
+  _Illusions connected with, Personal Identity_:--Illusions of Memory and
+  Sense of identity, 283, 284; idea of permanent self, how built up,
+  285-287; disturbances of sense of identity, 287-290; fallibility and
+  trustworthiness of Memory, 290-292.
+
+  NOTE.--Momentary Illusions of Self-consciousness, 293.
+
+
+  CHAPTER XI.
+
+  ILLUSIONS OF BELIEF.
+
+  Belief as Immediate or Intuitive, 294-296; simple and compound
+  Belief, 296.
+
+  A. _Simple Illusory Belief_:--
+
+      (1) Expectation: its nature, 297, 298; Is Expectation ever intuitive?
+        298; Expectation and Inference from the past, 299-301; Expectation
+        of new kinds of experience, 301, 302; Permanent Expectations
+        of remote events, 302; misrepresentation of future duration,
+        302-305; Imaginative transformation of future, 305-307.
+
+      (2) Quasi-Expectations: anticipation of extra-personal experiences,
+        307, 308; Retrospective Beliefs, 308-312.
+
+  B. _Compound Illusory Belief_:--
+
+      (1) Representations of permanent things: their structure, 312; our
+        representations of others as illusory, 312-315; our representation
+        of ourselves as illusory, 315; Illusion of self-esteem, 316-318;
+        genesis of illusory opinion of self, 318-322; Illusion in our
+        representations of classes of things, 322, 323; and in our views
+        of the world as a whole, 323, 324; tendency of belief towards
+        divergence, 325; and towards convergence, 326, 327.
+
+
+  CHAPTER XII.
+
+  RESULTS.
+
+  Range of Illusion, 328-330; nature and causes of Illusion in general,
+    331-334; Illusion identical with Fallacy, 334; Illusion as abnormal,
+    336, 337; question of common error, 337-339; evolutionist's conception
+    of error as maladaptation, 339-344; common intuitions
+    tested only by philosophy, 344; assumptions of science respecting
+    external reality, etc., 344-346; philosophic investigation of these
+    assumptions, 346-348; connection between scientific and philosophic
+    consideration of Illusion, 348-350; correction of Illusion and its
+    implications, 351, 352; Fundamental Intuitions and modern psychology,
+    352; psychology as positive science and as philosophy, 353-355;
+    points of resemblance between acknowledged Illusions and Fundamental
+    Intuitions, 355, 356; question of origin, and question of
+    validity, 356, 357; attitude of scientific mind towards philosophic
+    scepticism, 357-360; Persistent Intuitions must be taken as true,
+    360, 361.
+
+
+
+
+~ILLUSIONS.~
+
+
+
+
+CHAPTER I.
+
+THE STUDY OF ILLUSION.
+
+
+Common sense, knowing nothing of fine distinctions, is wont to draw a
+sharp line between the region of illusion and that of sane intelligence.
+To be the victim of an illusion is, in the popular judgment, to be
+excluded from the category of rational men. The term at once calls up
+images of stunted figures with ill-developed brains, half-witted
+creatures, hardly distinguishable from the admittedly insane. And this
+way of thinking of illusion and its subjects is strengthened by one of
+the characteristic sentiments of our age. The nineteenth century
+intelligence plumes itself on having got at the bottom of mediaeval
+visions and church miracles, and it is wont to commiserate the feeble
+minds that are still subject to these self-deceptions.
+
+According to this view, illusion is something essentially abnormal and
+allied to insanity. And it would seem to follow that its nature and
+origin can be best studied by those whose speciality it is to observe
+the phenomena of abnormal life. Scientific procedure has in the main
+conformed to this distinction of common sense. The phenomena of illusion
+have ordinarily been investigated by alienists, that is to say,
+physicians who are brought face to face with their most striking forms
+in the mentally deranged.
+
+While there are very good reasons for this treatment of illusion as a
+branch of mental pathology, it is by no means certain that it can be a
+complete and exhaustive one. Notwithstanding the flattering supposition
+of common sense, that illusion is essentially an incident in abnormal
+life, the careful observer knows well enough that the case is far
+otherwise.
+
+There is, indeed, a view of our race diametrically opposed to the
+flattering opinion referred to above, namely, the humiliating judgment
+that all men habitually err, or that illusion is to be regarded as the
+natural condition of mortals. This idea has found expression, not only
+in the cynical exclamation of the misanthropist that most men are fools,
+but also in the cry of despair that sometimes breaks from the weary
+searcher after absolute truth, and from the poet when impressed with the
+unreality of his early ideals.
+
+Without adopting this very disparaging opinion of the intellectual
+condition of mankind, we must recognize the fact that most men are
+sometimes liable to illusion. Hardly anybody is always consistently
+sober and rational in his perceptions and beliefs. A momentary fatigue
+of the nerves, a little mental excitement, a relaxation of the effort of
+attention by which we continually take our bearings with respect to the
+real world about us, will produce just the same kind of confusion of
+reality and phantasm, which we observe in the insane. To give but an
+example: the play of fancy which leads to a detection of animal and
+other forms in clouds, is known to be an occupation of the insane, and
+is rightly made use of by Shakespeare as a mark of incipient mental
+aberration in Hamlet; and yet this very same occupation is quite natural
+to children, and to imaginative adults when they choose to throw the
+reins on the neck of their phantasy. Our luminous circle of rational
+perception is surrounded by a misty penumbra of illusion. Common sense
+itself may be said to admit this, since the greatest stickler for the
+enlightenment of our age will be found in practice to accuse most of his
+acquaintance at some time or another of falling into illusion.
+
+If illusion thus has its roots in ordinary mental life, the study of it
+would seem to belong to the physiology as much as to the pathology of
+mind. We may even go further, and say that in the analysis and
+explanation of illusion the psychologist may be expected to do more than
+the physician. If, on the one hand, the latter has the great privilege
+of observing the phenomena in their highest intensity, on the other
+hand, the former has the advantage of being familiar with the normal
+intellectual process which all illusion simulates or caricatures. To
+this it must be added that the physician is naturally disposed to look
+at illusion mainly, if not exclusively, on its practical side, that is,
+as a concomitant and symptom of cerebral disease, which it is needful to
+be able to recognize. The psychologist has a different interest in the
+subject, being specially concerned to understand the mental antecedents
+of illusion and its relation to accurate perception and belief. It is
+pretty evident, indeed, that the phenomena of illusion form a region
+common to the psychologist and the mental pathologist, and that the
+complete elucidation of the subject will need the co-operation of the
+two classes of investigator.
+
+In the present volume an attempt will be made to work out the
+psychological side of the subject; that is to say, illusions will be
+viewed in their relation to the process of just and accurate perception.
+In the carrying out of this plan our principal attention will be given
+to the manifestations of the illusory impulse in normal life. At the
+same time, though no special acquaintance with the pathology of the
+subject will be laid claim to, frequent references will be made to the
+illusions of the insane. Indeed, it will be found that the two groups of
+phenomena--the illusions of the normal and of the abnormal
+condition--are so similar, and pass into one another by such insensible
+gradations, that it is impossible to discuss the one apart from the
+other. The view of illusion which will be adopted in this work is that
+it constitutes a kind of border-land between perfectly sane and vigorous
+mental life and dementia.
+
+And here at once there forces itself on our attention the question, What
+exactly is to be understood by the term "illusion"? In scientific works
+treating of the pathology of the subject, the word is confined to what
+are specially known as illusions of the senses, that is to say, to false
+or illusory perceptions. And there is very good reason for this
+limitation, since such illusions of the senses are the most palpable
+and striking symptoms of mental disease. In addition to this, it must be
+allowed that, to the ordinary reader, the term first of all calls up
+this same idea of a deception of the senses.
+
+At the same time, popular usage has long since extended the term so as
+to include under it errors which do not counterfeit actual perceptions.
+We commonly speak of a man being under an illusion respecting himself
+when he has a ridiculously exaggerated view of his own importance, and
+in a similar way of a person being in a state of illusion with respect
+to the past when, through frailty of memory, he pictures it quite
+otherwise than it is certainly known to have been.
+
+It will be found, I think, that there is a very good reason for this
+popular extension of the term. The errors just alluded to have this in
+common with illusions of sense, that they simulate the form of immediate
+or self-evident cognition. An idea held respecting ourselves or
+respecting our past history does not depend on any other piece of
+knowledge; in other words, is not adopted as the result of a process of
+reasoning. What I believe with reference to my past history, so far as I
+can myself recall it, I believe instantaneously and immediately, without
+the intervention of any premise or reason. Similarly, our notions of
+ourselves are, for the most part, obtained apart from any process of
+inference. The view which a man takes of his own character or claims on
+society he is popularly supposed to receive intuitively by a mere act of
+internal observation. Such beliefs may not, indeed, have all the
+overpowering force which belongs to illusory perceptions, for the
+intuition of something by the senses is commonly looked on as the most
+immediate and irresistible kind of knowledge. Still, they must be said
+to come very near illusions of sense in the degree of their self-evident
+certainty.
+
+Taking this view of illusion, we may provisionally define it as any
+species of error which counterfeits the form of immediate, self-evident,
+or intuitive knowledge, whether as sense-perception or otherwise.
+Whenever a thing is believed on its own evidence and not as a conclusion
+from something else, and the thing then believed is demonstrably wrong,
+there is an illusion. The term would thus appear to cover all varieties
+of error which are not recognized as fallacies or false inferences. If
+for the present we roughly divide all our knowledge into the two regions
+of primary or intuitive, and secondary or inferential knowledge, we see
+that illusion is false or spurious knowledge of the first kind, fallacy
+false or spurious knowledge of the second kind. At the same time, it is
+to be remembered that this division is only a very rough one. As will
+appear in the course of our investigation, the same error may be called
+either a fallacy or an illusion, according as we are thinking of its
+original mode of production or of the form which it finally assumes; and
+a thorough-going psychological analysis of error may discover that these
+two classes are at bottom very similar.
+
+As we proceed, we shall, I think, find an ample justification for our
+definition. We shall see that such illusions as those respecting
+ourselves or the past arise by very much the same mental processes as
+those which are discoverable in the production of illusory perceptions;
+and thus a complete psychology of the one class will, at the same time,
+contain the explanation of the other classes.
+
+The reader is doubtless aware that philosophers have still further
+extended the idea of illusion by seeking to bring under it beliefs which
+the common sense of mankind has always adopted and never begun to
+suspect. Thus, according to the idealist, the popular notion (the
+existence of which Berkeley, however, denied) of an external world,
+existing in itself and in no wise dependent on our perceptions of it,
+resolves itself into a grand illusion of sense.
+
+At the close of our study of illusions we shall return to this point. We
+shall there inquire into the connection between those illusions which
+are popularly recognized as such, and those which first come into view
+or appear to do so (for we must not yet assume that there are such)
+after a certain kind of philosophic reflection. And some attempt will be
+made to determine roughly how far the process of dissolving these
+substantial beliefs of mankind into airy phantasms may venture to go.
+
+For the present, however, these so-called illusions in philosophy will
+be ignored. It is plain that illusion exists only in antithesis to real
+knowledge. This last must be assumed as something above all question.
+And a rough and provisional, though for our purpose sufficiently
+accurate, demarcation of the regions of the real and the illusory seems
+to coincide with the line which common sense draws between what all
+normal men agree in holding and what the individual holds, whether
+temporarily or permanently, in contradiction to this. For our present
+purpose the real is that which is true for all. Thus, though physical
+science may tell us that there is nothing corresponding to our
+sensations of colour in the world of matter and motion which it
+conceives as surrounding us; yet, inasmuch as to all men endowed with
+the normal colour-sense the same material objects appear to have the
+same colour, we may speak of any such perception as practically true,
+marking it off from those plainly illusory perceptions which are due to
+some subjective cause, as, for example, fatigue of the retina.
+
+To sum up: in treating of illusions we shall assume, what science as
+distinguished from philosophy is bound to assume, namely, that human
+experience is consistent; that men's perceptions and beliefs fall into a
+consensus. From this point of view illusion is seen to arise through
+some exceptional feature in the situation or condition of the
+individual, which, for the time, breaks the chain of intellectual
+solidarity which under ordinary circumstances binds the single member to
+the collective body. Whether the common experience which men thus obtain
+is rightly interpreted is a question which does not concern us here. For
+our present purpose, which is the determination and explanation of
+illusion as popularly understood, it is sufficient that there is this
+general consensus of belief, and this may provisionally be regarded as
+at least practically true.
+
+
+
+
+CHAPTER II.
+
+THE CLASSIFICATION OF ILLUSIONS.
+
+
+If illusion is the simulation of immediate knowledge, the most obvious
+mode of classifying illusions would appear to be according to the
+variety of the knowledge which they simulate.
+
+Now, the popular psychology that floats about in the ordinary forms of
+language has long since distinguished certain kinds of unreasoned or
+uninferred knowledge. Of these the two best known are perception and
+memory. When I see an object before me, or when I recall an event in my
+past experience, I am supposed to grasp a piece of knowledge directly,
+to know something immediately, and not through the medium of something
+else. Yet I know differently in the two cases. In the first I know by
+what is called a presentative process, namely, that of sense-perception;
+in the second I know by a representative process, namely, that of
+reproduction, or on the evidence of memory. In the one case the object
+of cognition is present to my perceptive faculties; in the other it is
+recalled by the power of memory.
+
+Scientific psychology tends, no doubt, to break down some of these
+popular distinctions. Just as the zoologist sometimes groups together
+varieties of animals which the unscientific eye would never think of
+connecting, so the psychologist may analyze mental operations which
+appear widely dissimilar to the popular mind, and reduce them to one
+fundamental process. Thus recent psychology draws no sharp distinction
+between perception and recollection. It finds in both very much the same
+elements, though combined in a different way. Strictly speaking, indeed,
+perception must be defined as a presentative-representative operation.
+To the psychologist it comes to very much the same thing whether, for
+example, on a visit to Switzerland, our minds are occupied in
+_perceiving_ the distance of a mountain or in _remembering_ some
+pleasant excursion which we made to it on a former visit. In both cases
+there is a reinstatement of the past, a reproduction of earlier
+experience, a process of adding to a present impression a product of
+imagination--taking this word in its widest sense. In both cases the
+same laws of reproduction or association are illustrated.
+
+Just as a deep and exhaustive analysis of the intellectual operations
+thus tends to identify their various forms as they are distinguished by
+the popular mind, so a thorough investigation of the flaws in these
+operations, that is to say, the counterfeits of knowledge, will probably
+lead to an identification of the essential mental process which
+underlies them. It is apparent, for example, that, whether a man
+_projects_ some figment of his imagination into the external world,
+giving it, present material reality, or whether (if I may be allowed the
+term) he _retrojects_ it into the dim region of the past, and takes it
+for a reality that has been he is committing substantially the same
+blunder. The source of the illusion in both cases is one and the same.
+
+It might seem to follow from this that a scientific discussion of the
+subject would overlook the obvious distinction between illusions of
+perception and those of memory; that it would attend simply to
+differences in the mode of origination of the illusion, whatever its
+external form. Our next step, then, would appear to be to determine
+these differences in the mode of production.
+
+That there are differences in the origin and source of illusion is a
+fact which has been fully recognized by those writers who have made a
+special study of sense-illusions. By these the term illusion is commonly
+employed in a narrow, technical sense, and opposed to hallucination. An
+illusion, it is said, must always have its starting-point in some actual
+impression, whereas a hallucination has no such basis. Thus it is an
+illusion when a man, under the action of terror, takes a stump of a
+tree, whitened by the moon's rays, for a ghost. It is a hallucination
+when an imaginative person so vividly pictures to himself the form of
+some absent friend that, for the moment, he fancies himself actually
+beholding him. Illusion is thus a partial displacement of external fact
+by a fiction of the imagination, while hallucination is a total
+displacement.
+
+This distinction, which has been adopted by the majority of recent
+alienists[1], is a valuable one, and must not be lost sight of here. It
+would seem, from a psychological point of view, to be an important
+circumstance in the genesis of a false perception whether the
+intellectual process sets out from within or from without. And it will
+be found, moreover, that this distinction may be applied to all the
+varieties of error which I propose to consider. Thus, for example, it
+will be seen further on that a false recollection may set out either
+from the idea of some actual past occurrence or from a present product
+of the imagination.
+
+It is to be observed, however, that the line of separation between
+illusion and hallucination, as thus defined, is a very narrow one. In by
+far the largest number of hallucinations it is impossible to prove that
+there is no modicum of external agency co-operating in the production of
+the effect. It is presumable, indeed, that many, if not all,
+hallucinations have such a basis of fact. Thus, the madman who projects
+his internal thoughts outwards in the shape of external voices may, for
+aught we know, be prompted to do so in part by faint impressions coming
+from the ear, the result of those slight stimulations to which the organ
+is always exposed, even in profound silence, and which in his case
+assume an exaggerated intensity. And even if it is clearly made out that
+there are hallucinations in the strict sense, that is to say, false
+perceptions which are wholly due to internal causes, it must be conceded
+that illusion shades off into hallucination by steps which it is
+impossible for science to mark. In many cases it must be left an open
+question whether the error is to be classed as an illusion or as a
+hallucination.[2]
+
+For these reasons, I think it best not to make the distinction between
+illusion and hallucination the leading principle of my classification.
+However important psychologically, it does not lend itself to this
+purpose. The distinction must be kept in view and illustrated as far as
+possible. Accordingly, while in general following popular usage and
+employing the term illusion as the generic name, I shall, when
+convenient, recognize the narrow and technical sense of the term as
+answering to a species co-ordinate with hallucination.
+
+Departing, then, from what might seem the ideally best order of
+exposition, I propose, after all, to set out with the simple popular
+scheme of faculties already referred to. Even if they are,
+psychologically considered, identical operations, perception and memory
+are in general sufficiently marked off by a speciality in the form of
+the operation. Thus, while memory is the reproduction of something with
+a special reference of consciousness to its past existence, perception
+is the reproduction of something with a special reference to its present
+existence as a part of the presented object. In other words, though
+largely _representative_ when viewed as to its origin, perception is
+_presentative_ in relation to the object which is supposed to be
+immediately present to the mind at the moment.[3] Hence the convenience
+of recognizing the popular classification, and of making it our
+starting-point in the present case.
+
+All knowledge which has any appearance of being directly reached,
+immediate, or self-evident, that is to say, of not being inferred from
+other knowledge, may be divided into four principal varieties: Internal
+Perception or Introspection of the mind's own feelings;
+External Perception; Memory; and Belief, in so far as it simulates the
+form of direct knowledge. The first is illustrated in a man's
+consciousness of a present feeling of pain or pleasure. The second and
+the third kinds have already been spoken of, and are too familiar to
+require illustration. It is only needful to remark here that, under
+perception, or rather in close conjunction with it, I purpose dealing
+with the knowledge of other's feelings, in so far as this assumes the
+aspect of immediate knowledge. The term belief is here used to include
+expectations and any other kinds of conviction that do not fall under
+one of the other heads. An instance of a seemingly immediate belief
+would be a prophetic prevision of a coming disaster, or a man's
+unreasoned persuasion as to his own powers of performing a difficult
+task.
+
+It is, indeed, said by many thinkers that there are no legitimate
+immediate beliefs; that all our expectations and other convictions about
+things, in so far as they are sound, must repose on other genuinely
+immediate knowledge, more particularly sense-perception and memory.
+This difficult question need not be discussed here. It is allowed by all
+that there is a multitude of beliefs which we hold tenaciously and on
+which we are ready to act, which, to the mature mind, wear the
+appearance of intuitive truths, owing their cogency to nothing beyond
+themselves. A man's belief in his own merits, however it may have been
+first obtained, is as immediately assured to him as his recognition of a
+real object in the act of sense-perception. It may be added that many of
+our every-day working beliefs about the world in which we live, though
+presumably derived from memory and perception, tend to lose all traces
+of their origin, and to simulate the aspect of intuitions. Thus the
+proposition that logicians are in the habit of pressing on our
+attention, that "Men are mortal," seems, on the face of it, to common
+sense to be something very like a self-evident truth, not depending on
+any particular facts of experience.
+
+In calling these four forms of cognition immediate, I must not, however,
+be supposed to be placing them on the same logical level. It is plain,
+indeed, to a reflective mind that, though each may be called immediate
+in this superficial sense, there are perceptible differences in the
+degree of their immediacy. Thus it is manifest, after a moment's
+reflection, that expectation, so far as it is just, is not primarily
+immediate in the sense in which purely presentative knowledge is so,
+since it can be shown to follow from something else. So a general
+proposition, though through familiarity and innumerable illustrations it
+has acquired a self-evident character, is seen with a very little
+inspection to be less fundamentally and essentially so than the
+proposition, "I am now feeling pain;" and it will be found that even
+with respect to memory, when the remembered event is at all remote, the
+process of cognition approximates to a mediate operation, namely, one of
+inference. What the relative values of these different kinds of
+immediate knowledge are is a point which will have to be touched on at
+the end of our study. Here it must suffice to warn the reader against
+the supposition that this value is assumed to be identical.
+
+It might seem at a first glance to follow from this four-fold scheme of
+immediate or quasi-immediate knowledge that there are four varieties of
+illusion. And this is true in the sense that these four heads cover all
+the main varieties of illusion. If there are only four varieties of
+knowledge which can lay any claim to be considered immediate, it must be
+that every illusion will simulate the form of one of these varieties,
+and so be referable to the corresponding division.
+
+But though there are conceivably these four species of illusion, it does
+not follow that there are any actual instances of each class
+forthcoming. This we cannot determine till we have investigated the
+nature and origin of illusory error. For example, it might be found that
+introspection, or the immediate inspection of our own feelings or mental
+states, does not supply the conditions necessary to the production of
+such error. And, indeed, it is probable that most persons, antecedently
+to inquiry, would be disposed to say that to fall into error in the
+observation of what is actually going on in our own minds is
+impossible.
+
+With the exception of this first division, however, this scheme may
+easily be seen to answer to actual phenomena. That there are illusions
+of perception is obvious, since it is to the errors of sense that the
+term illusion has most frequently been confined. It is hardly less
+evident that there are illusions of memory. The peculiar difficulty of
+distinguishing between a past real event and a mere phantom of the
+imagination, illustrated in the exclamation, "I either saw it or dreamt
+it," sufficiently shows that memory is liable to be imposed on. Finally,
+it is agreed on by all that the beliefs we are wont to regard as
+self-evident are sometimes erroneous. When, for example, an imaginative
+woman says she knows, by mere intuition, that something interesting is
+going to happen, say the arrival of a favourite friend, she is plainly
+running the risk of being self-deluded. So, too, a man's estimate of
+himself, however valid for him, may turn out to be flagrantly false.
+
+In the following discussion of the subject I shall depart from the above
+order in so far as to set out with illusions of sense-perception. These
+are well ascertained, forming, indeed, the best-marked variety. And the
+explanation of these has been carried much further than that of the
+others. Hence, according to the rule to proceed from the known to the
+unknown, there will be an obvious convenience in examining these first
+of all. After having done this, we shall be in a position to inquire
+whether there is anything analogous in the region of introspection or
+internal perception. Our study of the errors of sense-perception will,
+moreover, prove the best preparation for an inquiry into the nature and
+mode of production of the remaining two varieties.[4]
+
+I would add that, in close connection with the first division, illusions
+of perception, I shall treat the subtle and complicated phenomena of
+dreams. Although containing elements which ought, according to
+strictness, to be brought under one of the other heads, they are, as
+their common appellation, "visions," shows, largely simulations of
+external, and more especially visual, perception.
+
+Dreams are no doubt sharply marked off from illusions of
+sense-perception by a number of special circumstances. Indeed, it may be
+thought that they cannot be adequately treated in a work that aims
+primarily at investigating the illusions of normal life, and should
+rather be left to those who make the pathological side of the subject
+their special study. Yet it may, perhaps, be said that in a wide sense
+dreams are a feature of normal life. And, however this be, they have
+quite enough in common with other illusions of perception to justify us
+in dealing with them in close connection with these.
+
+
+
+
+CHAPTER III.
+
+ILLUSIONS OF PERCEPTION: GENERAL.
+
+
+The errors with which we shall be concerned in this chapter are those
+which are commonly denoted by the term illusion, that is to say, those
+of sense. They are sometimes called deceptions of the senses; but this
+is a somewhat loose expression, suggesting that we can be deceived as to
+sensation itself, though, as we shall see later on, this is only true in
+a very restricted meaning of the phrase. To speak correctly,
+sense-illusions must be said to arise by a simulation of the form of
+just and accurate perceptions. Accordingly, we shall most frequently
+speak of them as illusions of perception.
+
+In order to investigate the nature of any kind of error, it is needful
+to understand the kind of knowledge it imitates, and so we must begin
+our inquiry into the nature of illusions of sense by a brief account of
+the psychology of perception; and, in doing this, we shall proceed best
+by regarding this operation in its most complete form, namely, that of
+visual perception.
+
+I may observe that in this analysis of perception I shall endeavour to
+keep to known facts, namely, the psychical phenomena or events which
+can be seen by the methods of scientific psychology to enter into the
+mental content called the percept. I do not now inquire whether such an
+analysis can help us to understand all that is meant by perception. This
+point will have to be touched later on. Here it is enough to say that,
+whatever our philosophy of perception may be, we must accept the
+psychological fact that the concrete mental state in the act of
+perception is built up out of elements, the history of which can be
+traced by the methods of mental science.
+
+
+_Psychology of Perception._
+
+Confining ourselves for the present to the mental, as distinguished from
+the physical, side of the operation, we soon find that perception is not
+so simple a matter as it might at first seem to be. When a man on a hot
+day looks at a running stream and "sees" the delicious coolness, it is
+not difficult to show that he is really performing an act of mental
+synthesis, or imaginative construction. To the sense-impression[5] which
+his eye now gives him, he adds something which past experience has
+bequeathed to his mind. In perception, the material of sensation is
+acted on by the mind, which embodies in its present attitude all the
+results of its past growth. Let us look at this process of synthesis a
+little more closely.
+
+When a sensation arises in the mind, it may, under certain
+circumstances, go unattended to. In that case there is no perception.
+The sensation floats in the dim outer regions of consciousness as a
+vague feeling, the real nature and history of which are unknown. This
+remark applies not only to the undefined bodily sensations that are
+always oscillating about the threshold of obscure consciousness, but to
+the higher sensations connected with the special organs of perception.
+The student in optics soon makes the startling discovery that his field
+of vision has all through his life been haunted with weird shapes which
+have never troubled the serenity of his mind just because they have
+never been distinctly attended to.
+
+The immediate result of this process of directing the keen glance of
+attention to a sensation is to give it greater force and distinctness.
+By attending to it we discriminate it from other feelings present and
+past, and classify it with like sensations previously received. Thus, if
+I receive a visual impression of the colour orange, the first
+consequence of attending to it is to mark it off from other
+colour-impressions, including those of red and yellow. And in
+recognizing the peculiar quality of the impression by applying to it the
+term orange, I obviously connect it with other similar sensations called
+by the same name. If a sensation is perfectly new, there cannot, of
+course, be this process of classifying, and in this case the closely
+related operation of discriminating it from other sensations is less
+exactly performed. But it is hardly necessary to remark that, in the
+mind of the adult, under ordinary circumstances, no perfectly new
+sensation ever occurs.
+
+When the sensation, or complex sensation, is thus defined and
+recognized, there follows the process of interpretation, by which I mean
+the taking up of the impression as an element into the complex mental
+state known as a percept. Without going into the philosophical question
+of what this process of synthesis exactly means, I may observe that, by
+common consent, it takes place to a large extent by help of a
+reproduction of sensations of various kinds experienced in the past.
+That is to say, the details in this act of combination are drawn from
+the store of mental recollections to which the growing mind is ever
+adding. In other words, the percept arises through a fusion of an actual
+sensation with mental representations or "images" of sensation.[6] Every
+element of the object that we thus take up in the act of perception, or
+put into the percept, as its actual size, distance, and so on, will be
+found to make itself known to us through mental images or revivals of
+past experiences, such as those we have in handling the object, moving
+to and from it, etc. It follows that if this is an essential ingredient
+in the act of perception, the process closely resembles an act of
+inference; and, indeed, Helmholtz distinctly calls the perception of
+distance an unconscious inference or a mechanically performed act of
+judgment.
+
+I have hinted that these recovered sensations include the feelings we
+experience in connection with muscular activity, as in moving our limbs,
+resisting or lifting heavy bodies, and walking to a distant object.
+Modern psychology refers the eye's instantaneous recognition of the most
+important elements of an object (its essential or "primary" qualities)
+to a reinstatement of such simple experiences as these. It is, indeed,
+these reproductions which are supposed to constitute the substantial
+background of our percepts.
+
+Another thing worth noting with respect to this process of filling up a
+sense-impression is that it draws on past sensations of the eye itself.
+Thus, when I look at the figure of an acquaintance from behind, my
+reproductive visual imagination supplies a representation of the
+impressions I am wont to receive when the more interesting aspect of the
+object, the front view, is present to my visual sense.[7]
+
+We may distinguish between different steps in the full act of visual
+recognition. First of all comes the construction of a material object of
+a particular figure and size, and at a particular distance; that is to
+say, the recognition of a tangible thing having certain simple
+space-properties, and holding a certain relation to other objects, and
+more especially our own body, in space. This is the bare perception of
+an object, which always takes place even in the case of perfectly new
+objects, provided they are seen with any degree of distinctness. It is
+to be added that the reference of a sensation of light or colour to such
+an object involves the inclusion of a quality answering to the
+sensation, as brightness, or blue colour, in the thing thus intuited.
+
+This part of the process of filling in, which is the most instantaneous,
+automatic, and unconscious, may be supposed to answer to the most
+constant and therefore the most deeply organized connections of
+experience; for, speaking generally, we never have an impression of
+colour, except when there are circumstances present which are fitted to
+yield us those simple muscular and tactual experiences through which the
+ideas of a particular form, size, etc., are pretty certainly obtained.
+
+The second step in this process of presentative construction is the
+recognition of an object as one of a class of things, for example,
+oranges, having certain special qualities, as a particular taste. In
+this step the connections of experience are less deeply organized, and
+so we are able to some extent, by reflection, to recognize it as a kind
+of intellectual working up of the materials supplied us by the past. It
+is to be noted that this process of recognition involves a compound
+operation of classifying impressions as distinguished from that simple
+operation by which a single impression, such as a particular colour, is
+known. Thus the recognition of such an object as an orange takes place
+by a rapid classing of a multitude of passive sensations of colour,
+light, and shade, and those active or muscular sensations which are
+supposed to enter into the visual perception of form.
+
+A still less automatic step in the process of visual recognition is that
+of identifying individual objects, as Westminster Abbey, or a friend,
+John Smith. The amount of experience that is here reproduced may be very
+large, as in the case of recognizing a person with whom we have had a
+long and intimate acquaintance.
+
+If the recognition of an object as one of a class, for example, an
+orange, involves a compound process of classing impressions, that of an
+individual object involves a still more complicated process. The
+identification of a friend, simple as this operation may at first
+appear, really takes place by a rapid classing of all the salient
+characteristic features which serve as the visible marks of that
+particular person.
+
+It is to be noted that each kind of recognition, specific and
+individual, takes place by a consciousness of likeness amid unlikeness.
+It is obvious that a new individual object has characters not shared in
+by other objects previously inspected. Thus, we at once class a man with
+a dark-brown skin, wearing a particular garb, as a Hindoo, though he may
+differ in a host of particulars from the other Hindoos that we have
+observed. In thus instantly recognizing him as a Hindoo, we must, it is
+plain, attend to the points of similarity, and overlook for the instant
+the points of dissimilarity. In the case of individual identification,
+the same thing happens. Strictly speaking, no object ever appears
+exactly the same to us on two occasions. Apart from changes in the
+object itself, especially in the case of living beings, there are
+varying effects of illumination, of position in relation to the eye, of
+distance, and so on, which very distinctly affect the visual impression
+at different times. Yet the fact of our instantly recognizing a familiar
+object in spite of these fluctuations of appearance, proves that we are
+able to overlook a very considerable amount of diversity when a certain
+amount of likeness is present.
+
+It is further to be observed that in these last stages of perception we
+approach the boundary line between perception and inference. To
+recognize an object as one of a class is often a matter of conscious
+reflection and judgment, even when the class is constituted by obvious
+material qualities which the senses may be supposed to apprehend
+immediately. Still more clearly does perception pass into inference when
+the class is constituted by less obvious qualities, which require a
+careful and prolonged process of recollection, discrimination, and
+comparison, for their recognition. Thus, to recognize a man by certain
+marks of gesture and manner as a military man or a Frenchman, though
+popularly called a perception, is much more of an unfolded process of
+conscious inference. And what applies to specific recognition applies
+still more forcibly to individual recognition, which is often a matter
+of very delicate conscious comparison and judgment. To say where the
+line should be drawn here between perception and observation on the one
+hand, and inference on the other, is clearly impossible. Our whole study
+of the illusions of perception will serve to show that the one shades
+off into the other too gradually to allow of our drawing a hard and fast
+line between them.
+
+Finally, it is to be noted that these last stages of perception bring us
+near the boundary line which separates objective experience as common
+and universal, and subjective or variable experience as confined to one
+or to a few. In the bringing of the object under a certain class of
+objects there is clearly room for greater variety of individual
+perception. For example, the ability to recognize a man as a Frenchman
+turns on a special kind of previous experience. And this transition from
+the common or universal to the individual experience is seen yet more
+plainly in the case of individual recognition. To identify an object,
+say a particular person, commonly presupposes some previous experience
+or knowledge of this object, and the existence in the past of some
+special relation of the recognizer to the recognized, if only that of an
+observer. In fact, it is evident that in this mode of recognition we
+have the transition from common perception to individual
+recollection.[8]
+
+While we may thus distinguish different steps in the process of visual
+recognition, we may make a further distinction, marking off a passive
+and an active stage in the process. The one may be called the stage of
+preperception, the other that of perception proper.[9] In the first the
+mind holds itself in a passive attitude, except in so far as the
+energies of external attention are involved. The impression here awakens
+the mental images which answer to past experiences according to the
+well-known laws of association. The interpretative image which is to
+transform the impression into a percept is now being formed by a mere
+process of suggestion.
+
+When the image is thus formed, the mind may be said to enter upon a more
+active stage, in which it now views the impression through the image, or
+applies this as a kind of mould or framework to the impression. This
+appears to involve an intensification of the mental image, transforming
+it from a representative to a presentative mental state, making it
+approximate somewhat to the full intensity of the sensation. In many of
+our instantaneous perceptions these two stages are indistinguishable to
+consciousness. Thus, in most cases, the recognition of size, distance,
+etc., takes place so rapidly that it is impossible to detect the two
+phases here separated. But in the classification of an object, or the
+identification of an individual thing, there is often an appreciable
+interval between the first reception of the impression and the final
+stage of complete recognition. And here it is easy to distinguish the
+two stages of preperception and perception. The interpretative image is
+slowly built up by the operation of suggestion, at the close of which
+the impression is suddenly illumined as by a flash of light, and takes a
+definite, precise shape.
+
+Now, it is to be noted that the process of preperception will be greatly
+aided by any circumstance that facilitates the construction of the
+particular interpretative image required. Thus, the more frequently a
+similar process of perception has been performed in the past, the more
+ready will the mind be to fall into the particular way of interpreting
+the impression. As G.H. Lewes well remarks, "The artist sees details
+where to other eyes there is a vague or confused mass; the naturalist
+sees an animal where the ordinary eye only sees a form." This is but one
+illustration of the seemingly universal mental law, that what is
+repeatedly done will be done more and more easily.
+
+The process of preperception may be shortened, not only by means of a
+_permanent_ disposition to frame the required interpretative scheme, the
+residuum of past like processes, but also by means of any _temporary_
+disposition pointing in the same direction. If, for example, the mind of
+a naturalist has just been occupied about a certain class of bird, that
+is to say, if he has been dwelling on the _mental image_ of this bird,
+he will recognize one at a distance more quickly than he would otherwise
+have done. Such a simple mental operation as the recognition of one of
+the less common flowers, say a particular orchid, will vary in duration
+according as we have or have not been recently forming an image of this
+flower. The obvious explanation of this is that the mental image of an
+object bears a very close resemblance to the corresponding percept,
+differing from it, indeed, in degree only, that is to say, through the
+fact that it involves no actual sensation. Here again we see illustrated
+a general psychological law, namely, that what the mind has recently
+done, it tends (within certain limits) to go on doing.
+
+It is to be noticed, further, that the perception of a single object or
+event is rarely an isolated act of the mind. We recognize and understand
+the things that surround us through their relations one to another.
+Sometimes the adjacent circumstances and events suggest a definite
+expectation of the new impression. Thus, for example, the sound of a gun
+heard during a walk in the country is instantly interpreted by help of
+suggestions due to the previous appearance of the sportsman, and the act
+of raising the gun to his shoulder. It may be added that the verbal
+suggestions of others act very much like the suggestions of external
+circumstances. If I am told that a gun is going to be fired, my mind is
+prepared for it just as though I saw the sportsman.[10]
+
+More frequently the effect of such surrounding circumstances is to give
+an air of familiarity to the new impression, to shorten the interval in
+which the required interpretative image is forthcoming. Thus, when
+travelling in Italy, the visual impression answering to a ruined temple
+or a bareheaded friar is construed much more rapidly than it would be
+elsewhere, because of the attitude of mind due to the surrounding
+circumstances. In all such cases the process of preperception connected
+with a given impression is effected more or less completely by the
+suggestions of other and related impressions.
+
+It follows from all that has been just said that our minds are never in
+exactly the same state of readiness with respect to a particular process
+of perceptional interpretation. Sometimes the meaning of an impression
+flashes on us at once, and the stage of preperception becomes
+evanescent. At other times the same impression will fail for an
+appreciable interval to divulge its meaning. These differences are, no
+doubt, due in part to variations in the state of attention at the
+moment; but they depend as well on fluctuations in the degree of the
+mind's readiness to look at the impression in the required way.
+
+In order to complete this slight analysis of perception, we must look
+for a moment at its physical side, that is to say, at the nervous
+actions which are known or supposed with some degree of probability to
+accompany it.
+
+The production of the sensation is known to depend on a certain external
+process, namely, the action of some stimulus, as light, on the
+sense-organ, which stimulus has its point of departure in the object,
+such as it is conceived by physical science. The sensation arises when
+the nervous process is transmitted through the nerves to the conscious
+centre, often spoken of as the sensorium, the exact seat of which is
+still a matter of some debate.
+
+The intensification of the sensation by the reaction of attention is
+supposed to depend on some reinforcement of the nervous excitation in
+the sensory centre proceeding from the motor regions, which are
+hypothetically regarded as the centre of attention.[11] The
+classification of the impression, again, is pretty certainly correlated
+with the physical fact that the central excitation calls into activity
+elements which have already been excited in the same way.
+
+The nervous counterpart of the final stage of perception, the synthesis
+of the sensation and the mental representation, is not clearly
+ascertained. A sensation clearly resembles a mental image in quality. It
+is most obviously marked off from the image by its greater vividness or
+intensity. Agreeably to this view, it is now held by a number of eminent
+physiologists and psychologists that the nervous process underlying a
+sensation occupies the same central region as that which underlies the
+corresponding image. According to this theory, the two processes differ
+in their degree of energy only, this difference being connected with the
+fact that the former involves, while the latter does not involve, the
+peripheral region of the nervous system. Accepting this view as on the
+whole well founded, I shall speak of an ideational, or rather an
+imaginational; and a sensational nervous process, and not of an
+ideational and a sensational centre.[12]
+
+The special force that belongs to the representative element in a
+percept, as compared with that of a pure "perceptional" image,[13] is
+probably connected with the fact that, in the case of actual perception,
+the nervous process underlying the act of imaginative construction is
+organically united to the initial sensational process, of which indeed
+it may be regarded as a continuation.
+
+For the physical counterpart of the two stages in the interpretative
+part of perception, distinguished as the passive stage of preperception,
+and the active stage of perception proper, we may, in the absence of
+certain knowledge, fall back on the hypothesis put forward by Dr. J.
+Hughlings Jackson, in the articles in _Brain_ already referred to,
+namely, that the former answers to an action of the right hemisphere of
+the brain, the latter to a subsequent action of the left hemisphere. The
+expediting of the process of preperception in those cases where it has
+frequently been performed before, is clearly an illustration of the
+organic law that every function is improved by exercise. And the
+temporary disposition to perform the process due to recent imaginative
+activity, is explained at once on the physical side by the supposition
+that an actual perception and a perceptional image involve the activity
+of the same nervous tracts. For, assuming this to be the case, it
+follows, from a well-known organic law, that a recent excitation would
+leave a temporary disposition in these particular structures to resume
+that particular mode of activity.
+
+What has here been said about visual perception will apply, _mutatis
+mutandis_, to other kinds. Although the eye is the organ of perception
+_par excellence_, our other senses are also avenues by which we intuit
+and recognize objects. Thus touch, especially when it is finely
+developed as it is in the blind, gives an immediate knowledge of
+objects--a more immediate knowledge, indeed, of their fundamental
+properties than sight. What makes the eye so vastly superior to the
+organ of touch as an instrument of perception, is first of all the range
+of its action, taking in simultaneously a large number of impressions
+from objects at a distance as well as near; and secondly, though this
+may seem paradoxical, the fact that it gives us so much indirectly, that
+is, by way of association and suggestion. This is the interesting side
+of visual perception, that, owing to the vast complex of distinguishable
+sensations of light and colour of various qualities and intensities,
+together with the muscular sensations attending the varying positions of
+the organ, the eye is able to recognize at any instant a whole external
+world with its fundamental properties and relations. The ear comes next
+to the eye in this respect, but only after a long interval, since its
+sensations (even in the case of musical combinations) do not
+simultaneously order themselves in an indefinitely large group of
+distinguishable elements, and since even the comparatively few
+sensations which it is capable of simultaneously receiving,
+being altogether passive--that is to say, having no muscular
+accompaniments--impart but little and vague information respecting the
+external order. It is plain, then, that in the study of illusion, where
+the indirectly known elements are the thing to be considered, the eye,
+and after this the ear, will mostly engage our attention.[14]
+
+So much it seemed needful to say about the mechanism of perception, in
+order to understand the slight disturbances of this mechanism that
+manifest themselves in sense-illusion. It may be added that our study of
+these illusions will help still further to elucidate the exact nature of
+perception. Normal mental life, as a whole, at once illustrates, and is
+illustrated by, abnormal. And while we need a rough provisional theory
+of accurate perception in order to explain illusory perception at all,
+the investigation of this latter cannot fail to verify and even render
+more complete the theory which it thus temporarily adopts.
+
+
+_Illusions of Perception._
+
+With this brief psychological analysis of perception to help us, let us
+now pass to the consideration of the errors incident to the process,
+with a view to classify them according to their psychological nature and
+origin.
+
+And here there naturally arises the question, How shall we define an
+illusion of perception? When trying to fix the definition of illusion in
+general, I practically disposed of this question. Nevertheless, as the
+point appears to me to be of some importance, I shall reproduce and
+expand one or two of the considerations then brought forward.
+
+It is said by certain, philosophers that perception, as a whole, is an
+illusion, inasmuch as it involves the fiction of a real thing
+independent of mind, yet somehow present to it in the act of
+sense-perception. But this is a question for philosophy, not for
+science. Science, including psychology, assumes that in perception there
+is something real, without inquiring what it may consist of, or what its
+meaning may be. And though in the foregoing analysis of perception,
+viewed as a complex mental phenomenon or psychical process, I have
+argued that a percept gets its concrete filling up out of elements of
+conscious experience or sensations, I have been careful not to contend
+that the particular elements of feeling thus represented are the
+_object_ of perception or the thing perceived. It may be that what we
+mean by a single object with its assemblage of qualities is much more
+than any number of such sensations; and it must be confessed that, on
+the face of it, it seems to be much more. And however this be, the
+question, What is meant by object; and is the common persuasion of the
+existence of such an entity in the act of perception accurate or
+illusory? must be handed over to philosophy.
+
+While in the following examination of sense-illusions we put out of
+sight what certain philosophers say about the illusoriness of perception
+as a whole, we shall also do well to leave out of account what physical
+science is sometimes supposed to tell us respecting a constant element
+of illusion in perception. The physicist, by reducing all external
+changes to "modes of motion," appears to leave no room in his
+world-mechanism for the secondary qualities of bodies, such as light
+and heat, as popularly conceived. Yet, while allowing this, I think we
+may still regard the attribution of qualities like colour to objects as
+in the main correct and answering to a real fact. When a person says an
+object is red, he is understood by everybody as affirming something
+which is true or false, something therefore which either involves an
+external fact or is illusory. It would involve an external fact whenever
+the particular sensation which he receives is the result of a physical
+action (other vibrations of a certain order), which would produce a like
+sensation in anybody else in the same situation and endowed with the
+normal retinal sensibility. On the other hand, an illusory attribution
+of colour would imply that there is no corresponding physical agency at
+work in the case, but that the sensation is connected with exceptional
+individual conditions, as, for example, altered retinal sensibility.
+
+We are now, perhaps, in a position to frame a rough definition of an
+illusion of perception as popularly understood. A large number of such
+phenomena may be described as consisting in the formation of percepts or
+quasi-percepts in the minds of individuals under external circumstances
+which would not give rise to similar percepts in the case of other
+people.
+
+A little consideration, however, will show that this is not an adequate
+definition of what is ordinarily understood by an illusion of sense.
+There are special circumstances which are fitted to excite a momentary
+illusion in all minds. The optical illusions due to the reflection and
+refraction of light are not peculiar to the individual, but arise in all
+minds under precisely similar external conditions.
+
+It is plain that the illusoriness of a perception is in these cases
+determined in relation to the sense-impressions of other moments and
+situations, or to what are presumably better percepts than the present
+one. Sometimes this involves an appeal from one sense to another. Thus,
+there is the process of verification of sight by touch, for example, in
+the case of optical images, a mode of perception which, as we have seen,
+gives a more direct cognition of external quality. Conversely, there may
+occasionally be a reference from touch to sight, when it is a question
+of discriminating two points lying very close to one another. Finally,
+the same sense may correct itself, as when the illusion of the
+stereoscope is corrected by afterwards looking at the two separate
+pictures.
+
+We may thus roughly define an illusion of perception as consisting in
+the formation of a quasi-percept which is peculiar to an individual, or
+which is contradicted by another and presumably more accurate percept.
+Or, if we take the meaning of the word common to include both the
+universal as contrasted with the individual experience, and the
+permanent, constant, or average, as distinguished from the momentary and
+variable percept, we may still briefly describe an illusion of
+perception as a deviation from the common or collective experience.
+
+
+_Sources of Sense-Illusion._
+
+Understanding sense-illusion in this way, let us glance back at the
+process of perception in its several stages or aspects, with the object
+of discovering what room occurs for illusion.
+
+It appears at first as if the preliminary stages--the reception,
+discrimination, and classification of an impression--would not offer the
+slightest opening for error. This part of the mechanism of perception
+seems to work so regularly and so smoothly that one can hardly conceive
+a fault in the process. Nevertheless, a little consideration will show
+that even here all does not go on with unerring precision.
+
+Let us suppose that the very first step is wanting--distinct attention
+to an impression. It is easy to see that this will favour illusion by
+leading to a confusion of the impression. Thus the timid man will more
+readily fall into the illusion of ghost-seeing than a cool-headed
+observant man, because he is less attentive to the actual impression of
+the moment. This inattention to the sense-impression will be found to be
+a great co-operating factor in the production of illusions.
+
+But if the sensation is properly attended to, can there be error through
+a misapprehension of what is actually in the mind at the moment? To say
+that there can may sound paradoxical, and yet in a sense this is
+demonstrable. I do not mean that there is an observant mind behind and
+distinct from the sensation, and failing to observe it accurately
+through a kind of mental short-sightedness. What I mean is that the
+usual psychical effect of the incoming nervous process may to some
+extent be counteracted by a powerful reaction of the centres. In the
+course of our study of illusions, we shall learn that it is possible for
+the quality of an impression, as, for example, of a sensation of colour,
+to be appreciably modified when there is a strong tendency to regard it
+in one particular way.
+
+Postponing the consideration of these, we may say that certain illusions
+appear clearly to take their start from an error in the process of
+classifying or identifying a present impression. On the physical side,
+we may say that the first stages of the nervous process, the due
+excitation of the sensory centre in accordance with the form of the
+incoming stimulation and the central reaction involved in the
+recognition of the sensation, are incomplete. These are so limited and
+comparatively unimportant a class, that it will be well to dispose of
+them at once.
+
+
+_Confusion of the Sense-Impression._
+
+The most interesting case of such an error is where the impression is
+unfamiliar and novel in character. I have already remarked that in the
+mental life of the adult perfectly new sensations never occur. At the
+same time, comparatively novel impressions sometimes arise. Parts of the
+sensitive surface of the body which rarely undergo stimulation are
+sometimes acted on, and at other times they receive partially new modes
+of stimulation. In such cases it is plain that the process of classing
+the sensation or recognizing it is not completed. It is found that
+whenever this happens there is a tendency to exaggerate the intensity of
+the sensation. The very fact of unfamiliarity seems to give to the
+sensation a certain exciting character. As something new and strange, it
+for the instant slightly agitates and discomposes the mind. Being unable
+to classify it with its like, we naturally magnify its intensity, and
+so tend to ascribe it to a disproportionately large cause.
+
+For instance, a light bandage worn about the body at a part usually free
+from pressure is liable to be conceived as a weighty mass. The odd sense
+of a big cavity in the mouth, which we experience just after the loss of
+a tooth, is probably another illustration of this principle. And a third
+example may also be supplied from the recollection of the dentist's
+patient, namely, the absurd imagination which he tends to form as to
+what is actually going on in his mouth when a tooth is being bored by a
+modern rotating drill. It may be found that the same principle helps to
+account for the exaggerated importance which we attach to the
+impressions of our dreams.
+
+It is evident that all indistinct impressions are liable to be wrongly
+classed. Sensations answering to a given colour or form, are, when
+faint, easily confused with other sensations, and so an opening occurs
+for illusion. Thus, the impressions received from distant objects are
+frequently misinterpreted, and, as we shall see by-and-by, it is in this
+region of hazy impression that imagination is wont to play its most
+startling pranks.
+
+It is to be observed that the illusions arising from wrong
+classification will be more frequent in the case of those senses where
+discrimination is low. Thus, it is much easier in a general way to
+confuse two sensations of smell than two sensations of colour. Hence the
+great source of such errors is to be found in that mass of obscure
+sensation which is connected with the organic processes, as digestion,
+respiration, etc., together with those varying tactual and motor
+feelings, which result from what is called the subjective stimulation of
+the tactual nerves, and from changes in the position and condition of
+the muscles. Lying commonly in what is known as the sub-conscious region
+of mind, undiscriminated, vague, and ill-defined, these sensations, when
+they come to be specially attended to, readily get misapprehended, and
+so lead to illusion, both in waking life and in sleep. I shall have
+occasion to illustrate this later on.
+
+With these sensations, the result of stimulations coming from remote
+parts of the organism, may be classed the ocular impressions which we
+receive in indirect vision. When the eye is not fixed on an object, the
+impression, involving the activity of some-peripheral region of the
+retina, is comparatively indistinct. This will be much more the case
+when the object lies at a distance for which the eye is not at the time
+accommodated. And in these circumstances, when we happen to turn our
+attention to the impression, we easily misapprehend it, and so fall into
+illusion. Thus, it has been remarked by Sir David Brewster, in his
+_Letters on Natural Magic_ (letter vii.), that when looking through a
+window at some object beyond, we easily suppose a fly on the window-pane
+to be a larger object, as a bird, at a greater distance.[15]
+
+While these cases of a confusion or a wrong classification of the
+sensation are pretty well made out, there are other illusions or
+quasi-illusions respecting which it is doubtful whether they should be
+brought under this head. For example, it was found by Weber, that when
+the legs of a pair of compasses are at a certain small distance apart
+they will be felt as two by some parts of the tactual surface of the
+body, but only as one by other parts. How are we to regard this
+discrepancy? Must we say that in the latter case there are two
+sensations, only that, being so similar, they are confused one with
+another? There seems some reason for so doing, in the fact that, by a
+repeated exercise of attention to the experiment, they may afterwards be
+recognized as two.
+
+We here come on the puzzling question, How much in the character of the
+sensation must be regarded as the necessary result of the particular
+mode of nervous stimulation at the moment, together with the laws of
+sensibility, and how much must be put down to the reaction of the mind
+in the shape of attention and discrimination? For our present purpose we
+may say that, whenever a deliberate effort of attention does not suffice
+to alter the character of a sensation, this may be pretty safely
+regarded as a net result of the nervous process, and any error arising
+may be referred to the later stages of the process of perception. Thus,
+for example, the taking of the two points of a pair of compasses for
+one, where the closest attention does not discover the error, is best
+regarded as arising, not from a confusion of the sense-impression, but
+from a wrong interpretation of a sensation, occasioned by an
+overlooking of the limits of local discriminative sensibility.
+
+
+_Misinterpretation of the Sense-Impression._
+
+Enough has been said, perhaps, about those errors of perception which
+have their root in the initial process of sensation. We may now pass to
+the far more important class of illusions which are related to the later
+stages of perception, that is to say, the process of interpreting the
+sense-impression. Speaking generally, one may describe an illusion of
+perception as a misinterpretation. The wrong kind of interpretative
+mental image gets combined with the impression, or, if with Helmholtz we
+regard perception as a process of "unconscious inference," we may say
+that these illusions involve an unconscious fallacious conclusion. Or,
+looking at the physical side of the operation, it may be said that the
+central course taken by the nervous process does not correspond to the
+external relations of the moment.
+
+As soon as we inspect these illusions of interpretation, we see that
+they fall into two divisions, according as they are connected with the
+process of _suggestion_, that is to say, the formation of the
+interpretative image so far as determined by links of association with
+the actual impression, or with an independent process of _preperception_
+as explained above. Thus, for example, we fall into the illusion of
+hearing two voices when our shout is echoed back, just because the
+second auditory impression irresistibly calls up the image of a second
+shouter. On the other hand, a man experiences the illusion of seeing
+spectres of familiar objects just after exciting his imagination over a
+ghost-story, because the mind is strongly predisposed to frame this kind
+of percept. The first class of illusions arises from without, the
+sense-impression being the starting-point, and the process of
+preperception being controlled by this. The second class arises rather
+from within, from an independent or spontaneous activity of the
+imagination. In the one case the mind is comparatively passive; in the
+other it is active, energetically reacting on the impression, and
+impatiently anticipating the result of the normal process of
+preperception. Hence I shall, for brevity's sake, commonly speak of them
+as Passive and Active Illusions.[16]
+
+I may, perhaps, illustrate these two classes of illusion by the simile
+of an interpreter poring over an old manuscript. The first would be due
+to some peculiarity in the document misleading his judgment, the second
+to some caprice or preconceived notion in the interpreter's mind.
+
+It is not difficult to define conjecturally the physiological conditions
+of these two large classes of illusion. On the physical side, an
+illusion of sense, like a just perception, is the result of a fusion of
+the nervous process answering to a sensation with a nervous process
+answering to a mental image. In the case of passive illusions, this
+fusion may be said to take place in consequence of some point of
+connection between the two. The existence of such a connection appears
+to be involved in the very fact of suggestion, and may be said to be
+the organic result of frequent conjunctions of the two parts of the
+nervous operation in our past history. In the case of active illusions,
+however, which spring rather from the independent energy of a particular
+mode of the imagination, this point of organic connection is not the
+only or even the main thing. In many cases, as we shall see, there is
+only a faint shade of resemblance between the present impression and the
+mental image with which it is overlaid. The illusions dependent on
+vivid, expectation thus answer much less to an objective conjunction of
+past experiences than to a capricious subjective conjunction of mental
+images. Here, then, the fusion of nervous processes must have another
+cause. And it is not difficult to assign such a cause. The antecedent
+activity of imagination doubtless involves as its organic result a
+powerful temporary disposition in the nervous structures concerned to go
+on acting. In other words, they remain in a state of sub-excitation,
+which can be raised to full excitation by a slight additional force. The
+more powerful this disposition in the centres involved in the act of
+imagination, the less the additional force of external stimulus required
+to excite them to full activity.
+
+Considering the first division, passive illusions, a little further, we
+shall see that they may be broken up into two sub-classes, according to
+the causes of the errors. In a general way we assume that the impression
+always answers to some quality of the object which is perceived, and
+varies with this; that, for example, our sensation of colour invariably
+represents the quality of external colour which we attribute to the
+object. Or, to express it physically, we assume that the external force
+acting on the sense-organ invariably produces the same effect, and that
+the effect always varies with the external cause. But this assumption,
+though true in the main, is not perfectly correct. It supposes that the
+organic conditions are constant, and that the organic process faithfully
+reflects the external operation. Neither of these suppositions is
+strictly true. Although in general we may abstract from the organism and
+view the relation between the external fact and the mental impression as
+direct, we cannot always do so.
+
+This being so, it is possible for errors of perception to arise through
+peculiarities of the nervous organization itself. Thus, as I have just
+observed, sensibility has its limits, and these limits are the
+starting-point in a certain class of widely shared or _common_
+illusions. An example of this variety is the taking of the two points of
+a pair of compasses for one by the hand, already referred to. Again, the
+condition of the nervous structures varies indefinitely, so that one and
+the same stimulus may, in the case of two individuals, or of the same
+individual at different times, produce widely unlike modes of sensation.
+Such variations are clearly fitted to lead to gross _individual_ errors
+as to the external cause of the sensation. Of this sort is the illusory
+sense of temperature which we often experience through a special state
+of the organ employed.
+
+While there are these errors of interpretation due to some peculiarity
+of the organization, there are others which involve no such peculiarity,
+but arise through the special character or exceptional conformation of
+the environment at the moment. Of this order are the illusions connected
+with the reflection of light and sound. We may, perhaps, distinguish the
+first sub-class as organically conditioned illusions, and the second as
+extra-organically determined illusions. It may be added that the latter
+are roughly describable as common illusions. They thus answer in a
+measure to the first variety of organically conditioned illusions,
+namely, those connected with the limits of sensibility. On the other
+hand, the active illusions, being essentially individual or subjective,
+may be said to correspond to the other variety of this class--those
+connected with variations of sensibility.
+
+Our scheme of sense-illusions is now complete. First of all, we shall
+take up the passive illusions, beginning with those which are
+conditioned by special circumstances in the organism. After that we
+shall illustrate those which depend on peculiar circumstances in the
+environment. And finally, we shall separately consider what I have
+called the active illusions of sense.
+
+It is to be observed that these illusions of perception properly so
+called, namely, the errors arising from a wrong interpretation of an
+impression, and, not from a confusion of one impression with another are
+chiefly illustrated in the region of the two higher senses, sight and
+hearing. For it is here, as we have seen, that the interpretative
+imagination has most work to do in evolving complete percepts of
+material, tangible objects, having certain relations in space, out of a
+limited and homogeneous class of sensations, namely, those of light and
+colour, and of sound. As I have before observed, tactual perception, in
+so far as it is the recognition of an object of a certain size,
+hardness, and distance from our body, involves the least degree of
+interpretation, and so offers little room for error; it is only when
+tactual perception amounts to the _recognition_ of an individual object,
+clothed with secondary as well as primary qualities, that an opening for
+palpable error occurs.
+
+With respect, however, to the first sub-class of these illusions,
+namely, those arising from organic peculiarities which give a twist, so
+to speak, to the sensation, no very marked contrast between the
+different senses presents itself. So that in illustrating this group we
+shall be pretty equally concerned with the various modes of perception
+connected with the different senses.
+
+It may be said once for all that in thus marking off from one another
+certain groups of illusion, I am not unmindful of the fact that these
+divisions answer to no very sharp natural distinctions. In fact, it will
+be found that one class gradually passes into the other, and that the
+different characteristics here separated often combine in a most
+perplexing way. All that is claimed for this classification is that it
+is a convenient mode of mapping out the subject.
+
+
+
+
+CHAPTER IV.
+
+ILLUSIONS OF PERCEPTION--_continued_.
+
+A. _Passive Illusions (a) as determined by the Organism._
+
+
+In dealing with the illusions which are related to certain peculiarities
+in the nervous organism and the laws of sensibility, I shall commence
+with those which are connected with certain limits of sensibility.
+
+
+_Limits of Sensibility._
+
+To begin with, it is known that the sensation does not always answer to
+the external stimulus in its degree or intensity. Thus, a certain amount
+of stimulation is necessary before any sensation arises. And this will,
+of course, be greater when there is little or no attention directed to
+the impression, that is to say, no co-operating central reaction. Thus
+it happens that slight stimuli go overlooked, and here illusion may have
+its starting-point. The most familiar example of such slight errors is
+that of movement. When we are looking at objects, our ocular muscles are
+apt to execute very slight movements which escape our notice. Hence we
+tend, under certain circumstances, to carry over the retinal result of
+the movement, that is to say, the impression produced by a shifting of
+the parts of the retinal image to new nervous elements, to the object
+itself, and so to transform a "subjective" into an "objective" movement.
+In a very interesting work on apparent or illusory movements, Professor
+Hoppe has fully investigated the facts of such slight movements, and
+endeavoured to specify their causes.[17]
+
+Again, even when the stimulus is sufficient to produce a conscious
+impression, the degree of the feeling may not represent the degree of
+the stimulus. To take a very inconspicuous case, it is found by Fechner
+that a given increase of force in the stimulus produces a less amount of
+difference in the resulting sensations when the original stimulus is a
+powerful one than when it is a feeble one. It follows from this, that
+differences in the degree of our sensations do not exactly correspond to
+objective differences. For example, we tend to magnify the differences
+of light among objects, all of which are feebly illuminated, that is to
+say, to see them much more removed from one another in point of
+brightness than when they are more strongly illuminated. Helmholtz
+relates that, owing to this tendency, he has occasionally caught
+himself, on a dark night, entertaining the illusion that the
+comparatively bright objects visible in twilight were self-luminous.[18]
+
+Again, there are limits to the conscious separation of sensations which
+are received together, and this fact gives rise to illusion. In general,
+the number of distinguishable sensations answers to the number of
+external causes; but this is not always the case, and here we naturally
+fall into the error of mistaking the number of the stimuli. Reference
+has already been made to this fact in connection with the question
+whether consciousness can be mistaken as to the character of a present
+feeling.
+
+The case of confusing two impressions when the sensory fibres involved
+are very near one another, has already been alluded to. Both in touch
+and in sight we always take two or more points for one when they are
+only separated by an interval that falls below the limits of local
+discrimination. It seems to follow from this that our perception of the
+world as a continuum, made up of points perfectly continuous one with
+another may, for what we know, be illusory. Supposing the universe to
+consist of atoms separated by very fine intervals, then it is
+demonstrable that it would appear to our sensibility as a continuum,
+just as it does now.[19]
+
+Two or more simultaneous sensations are indistinguishable from one
+another, not only when they have nearly the same local origin, but under
+other circumstances. The blending of partial sensations of tone in a
+_klang_-sensation, and the coalescence in certain cases of the
+impressions received by way of the two retinas, are examples of this. It
+is not quite certain what determines this fusion of two simultaneous
+feelings. It may be said generally that it is favoured by similarity
+between the sensations;[20] by a comparative feebleness of one of the
+feelings; by the fact of habitual concomitance, the two sensations
+occurring rarely, if ever, in isolation; and by the presence of a mental
+disposition to view them as answering to one external object. These
+considerations help us to explain the coalescence of the retinal
+impressions and its limits, the fusion of partial tones, and so on.[21]
+
+It is plain that this fusion of sensations, whatever its exact
+conditions may be, gives rise to error or wrong interpretation of the
+sense-impression. Thus, to take the points of two legs of a pair of
+compasses for one point is clearly an illusion of perception. Here is
+another and less familiar example. Very cold and smooth surfaces, as
+those of metal, often appear to be wet. I never feel sure, after wiping
+the blades of my skates, that they are perfectly dry, since they always
+seem more or less damp to my hand. What is the reason of this? Helmholtz
+explains the phenomenon by saying that the feeling we call by the name
+of wetness is a compound sensation consisting of one of temperature and
+one of touch proper. These sensations occurring together so frequently,
+blend into one, and so we infer, according to the general instinctive
+tendency already noticed, that there is one specific quality answering
+to the feeling. And since the feeling is nearly always produced by
+surfaces moistened by cold liquid, we refer it to this circumstance, and
+speak of it as a feeling of wetness. Hence, when the particular
+conjunction of sensations arises apart from this external circumstance,
+we erroneously infer its presence.[22]
+
+The most interesting case of illusion connected with the fusion of
+simultaneous sensations, is that of single vision, or the deeply
+organized habit of combining the sensations of what are called the
+corresponding points of the two retinas. This coalescence of two
+sensations is so far erroneous since it makes us overlook the existence
+of two distinct external agencies acting on different parts of the
+sensitive surface of the body. And this is the more striking in the case
+of looking at solid objects, since here it is demonstrable that the
+forces acting on the two retinas are not perfectly similar.
+Nevertheless, such a coalescence plainly answers to the fact that these
+external agencies usually arise in one and the same object, and this
+unity of the object is, of course, the all-important thing to be sure
+of.
+
+This habit may, however, beget palpable illusion in another way. In
+certain exceptional cases the coalescence does not take place, as when I
+look at a distant object and hold a pencil just before my eyes.[23] And
+in this case the organized tendency to take one visual impression for
+one object asserts its force, and I tend to fall into the illusion of
+seeing two separate pencils. If I do not wholly lapse into the error, it
+is because my experience has made me vaguely aware that double images
+under these circumstances answer to one object, and that if there were
+really two pencils present I should have four visual impressions.
+
+Once more, it is a law of sensory stimulation that an impression
+persists for an appreciable time after the cessation of the action of
+the stimulus. This "after sensation" will clearly lead to illusion, in
+so far as we tend to think of the stimulus as still at work. It forms,
+indeed, as will be seen by-and-by, the simplest and lowest stage of
+hallucination. Sometimes this becomes the first stage of a palpable
+error. After listening to a child crying for some time the ear easily
+deceives itself into supposing that the noise is continued when it has
+actually ceased. Again, after taking a bandage from a finger, the
+tingling and other sensations due to the pressure sometimes persist for
+a good time, in which case they easily give rise to an illusion that the
+finger is still bound.
+
+It follows from this fact of the reverberation of the nervous structures
+after the removal of a stimulus, that whenever two discontinuous
+stimulations follow one another rapidly enough, they will appear
+continuous. This fact is a fruitful source of optical illusion. The
+appearance of a blending of the stripes of colours on a rotating disc or
+top, of the formation of a ring of light by swinging round a piece of
+burning wood, and the illusion of the toy known as the thaumatrope, or
+wheel of life, all depend on this persistence of retinal impression.
+Many of the startling effects of sleight of hand are undoubtedly due in
+part to this principle. If two successive actions or sets of
+circumstances to which the attention of the spectator is specially
+directed follow one another by a very narrow interval of time, they
+easily appear continuous, so that there seems absolutely no time for the
+introduction of an intermediate step.[24]
+
+There is another limit to sensibility which is in a manner the opposite
+to the one just named. It is a law of nervous stimulation that a
+continued activity of any structure results in less and less psychic
+result, and that when a stimulus is always at work it ceases in time to
+have any appreciable effect. The common illustration of this law is
+drawn from the region of sound. A constant noise, as of a mill, ceases
+to produce any conscious sensation. This fact, it is plain, may easily
+become the commencement of an illusion. Not only may we mistake a
+measure of noise for perfect silence,[25] we may misconceive the real
+nature of external circumstances by overlooking some continuous
+impression.
+
+Curious illustrations of this effect are found in optical illusions,
+namely, the errors we make respecting the movement of stationary objects
+after continued movement of the eyes. When, for example, in a railway
+carriage we have for some time been following the (apparent) movement of
+objects, as trees, etc., and turn our eyes to an apparently stationary
+object, as the carpet of the compartment, this seems to move in the
+contrary direction to that of the trees. Helmholtz's explanation of this
+illusion is that when we suppose that we are fixing our eye on the
+carpet we are really continuing to move it over the surface by reason of
+the organic tendency, already spoken of, to go on doing anything that
+has been done. But since we are unaware of this prolonged series of
+ocular movements, the muscular feelings having become faint, we take the
+impression produced by the sliding of the picture over the retina to be
+the result of a movement of the object.[26]
+
+Another limit to our sensibility, which needs to be just touched on
+here, is known by the name of the specific energy of the nerves. One and
+the same nerve-fibre always reacts in a precisely similar way, whatever
+the nature of the stimulus. Thus, when the optic nerve is stimulated in
+any manner, whether by light, mechanical pressure, or an electric
+current, the same effect, a sensation of light, follows.[27] In a usual
+way, a given class of nerve-fibre is only stimulated by one kind of
+stimulus. Thus, the retina, in ordinary circumstances, is stimulated by
+light. Owing to this fact, there has arisen a deeply organized habit of
+translating the impression in one particular way. Thus, I instinctively
+regard a sensation received by means of the optic nerve as one caused by
+light.
+
+Accordingly, whenever circumstances arise in which a like sensation is
+produced by another kind of stimulus, we fall into illusion. The
+phosphenes, or circles of light which are seen when the hinder part of
+the eyeball is pressed, may be said to be illusory in so far as we
+speak of them as perceptions of light, thus referring them to the
+external physical agency which usually causes them. The same remark
+applies to those "subjective sensations," as they are called, which are
+known to have as their physical cause subjective stimuli, consisting, in
+the case of sight, in varying conditions of the peripheral organ, as
+increased blood-pressure. Strictly speaking, such simple feelings as
+these appear to be, involve an ingredient of false perception: in saying
+that we _perceive_ light at all, we go beyond the pure sensation,
+interpreting this wrongly.
+
+Very closely connected with this limitation of our sensibility is
+another which refers to the consciousness of the local seat, or origin
+of the impression. This has so far its basis in the sensation itself as
+it is well known that (within the limits of local discrimination,
+referred to above) sensations have a particular "local" colour, which
+varies in the case of each of the nervous fibres by the stimulation of
+which they arise.[28] But though this much is known through a difference
+in the sensibility, nothing more is known. Nothing can certainly be
+ascertained by a mere inspection of the sensation as to the distance the
+nervous process has travelled, whether from the peripheral termination
+of the fibre or from some intermediate point.
+
+In a general way, we refer our sensations to the peripheral endings of
+the nerves concerned, according to what physiologists have called "the
+law of eccentricity." Thus I am said to feel the pain caused by a
+bruise in the foot in the member itself. This applies also to some of
+the sensations of the special senses. Thus, impressions of taste are
+clearly localized in the corresponding peripheral terminations.
+
+With respect to the sense of smell, and still more to those of hearing
+and sight, where the impression is usually caused by an object at a
+distance from the peripheral organ, our attention to this external cause
+leads us to overlook in part the "bodily seat" of the sensation. Yet
+even here we are dimly aware that the sensation is received by way of a
+particular part of the sensitive surface, that is to say, by a
+particular sense-organ. Thus, though referring an odour to a distant
+flower, we perceive that the sensation of odour has its bodily origin in
+the nose. And even in the case of hearing and sight, we vaguely refer
+the impressions, as such, to the appropriate sense-organ. There is,
+indeed, in these cases a double local reference, a faint one to the
+peripheral organ which is acted on, and a more distinct one to the
+object or the force in the environment which acts on this.
+
+Now, it may be said that the act of localization is in itself distinctly
+illusory, since it is known that the sensation first arises in
+connection with the excitation of the sensory _centre_, and not of the
+peripheral fibre.[29] Yet it must at least be allowed that this
+localization of sensation answers to the important fact that, under
+usual circumstances, the agency producing the sensation is applied at
+this particular point of the organism, the knowledge of which point is
+supposed by modern psychologists to have been very slowly learnt by the
+individual and the race, through countless experiments with the moving
+organ of touch, assisted by the eye.
+
+Similarly, the reference of the impression, in the case of hearing and
+sight, to an object in the environment, though, as we have seen, from
+one point of view illusory, clearly answers to a fact of our habitual
+experience; for in an immense preponderance of cases at least a visual
+or auditory impression does arise through the action on the sense-organ
+of a force (ether or air waves) proceeding from a distant object.
+
+In some circumstances, however, even this element of practical truth
+disappears, and the localization of the impression, both within and
+without the organism, becomes altogether illusory. This result is
+involved in the illusions, already spoken of, which arise from the
+instinctive tendency to refer sensations to the ordinary kind of
+stimulus. Thus, when a feeling resulting from a disturbance in the optic
+nerve is interpreted as one of external light vaguely felt to be acting
+on the eye, or one resulting from some action set up in the auditory
+fibre as a sensation of external sound vaguely felt to be entering the
+ear, we see that the error of localization is a consequence of the other
+error already characterized.
+
+As I have already observed, an excitation of a nerve at any other point
+than the peripheral termination, occurs but rarely in normal life. One
+familiar instance is the stimulation of the nerve running to the hand
+and fingers, by a sharp blow on the elbow over which it passes. As
+everybody knows, this gives rise to a sense of pain at the _extremities_
+of the nerve. The most common illustration of such errors of
+localization is found in subjective sensations, such as the impression
+we sometimes have of something creeping over the skin, of a disagreeable
+taste in the mouth, of luminous spots floating across the field of
+vision, and so on. The exact physiological seat of these is often a
+matter of conjecture only; yet it may safely be said that in many
+instances the nervous excitation originates at some point considerably
+short of its peripheral extremity: in which case there occurs the
+illusion of referring the impressions to the peripheral sense-organ, and
+to an external force acting on this.
+
+The most striking instances of these errors of localization are found in
+abnormal circumstances. It is well known that a man who has lost a leg
+refers all sensations arising from a stimulation of the truncated fibres
+to his lost foot, and in some cases has even to convince himself of the
+non-existence of his lost member by sight or touch. Patients often
+describe these experiences in very odd language. "If," says one of Dr.
+Weir Mitchell's patients, "I should say I am more sure of the leg which
+ain't than the one which air, I guess I should be about correct."[30]
+
+There is good reason for supposing that this source of error plays a
+prominent part in the illusions of the insane. Diseased centres may be
+accompanied by disordered peripheral structures, and so subjective
+sensation may frequently be the starting-point of the wildest illusions.
+Thus, a patient's horror of poison may have its first origin in some
+subjective gustatory sensation. Similarly, subjective tactual sensations
+may give rise to gross illusions, as when a patient "feels" his body
+attacked by foul and destructive creatures.
+
+It may be well to remark that this mistaken interpretation of the seat
+or origin of subjective sensation is closely related to hallucination.
+In so far as the error involves the ascription of the sensation to a
+force external to the sense-organ, this part of the mental process must,
+when there is no such force present, be viewed as hallucinatory. Thus,
+the feeling of something creeping over the skin is an hallucination in
+the sense that it implies the idea of an object external to the skin.
+Similarly, the projection of an ocular impression due to retinal
+disturbance into the external field of vision, may rightly be named an
+hallucination. But the case is not always so clear as this. Thus, for
+example, when a gustatory sensation is the result of an altered
+condition of the saliva, it may be said that the error is as much an
+illusion as an hallucination.[31]
+
+In a wide sense, again, all errors connected with those subjective
+sensations which arise from a stimulation of the peripheral regions of
+the nerve may be called illusions rather than hallucinations. Or, if
+they must be called hallucinations, they may be distinguished as
+"peripheral" from those "central" hallucinations which arise through an
+internal automatic excitation of the sensory centre. It is plain from
+this that the region of subjective sensation is an ambiguous region,
+where illusion and hallucination mix and become confused. To this point
+I shall have occasion to return by-and-by.
+
+I have now probably said enough respecting the illusions that arise
+through the fact of there being fixed limits to our sensibility. The
+_rationale_ of these illusions is that whenever the limit is reached, we
+tend to ignore it and to interpret the impression in the customary way.
+
+
+_Variations of Sensibility._
+
+We will now pass to a number of illusions which depend on something
+variable in the condition of our sensibility, or some more or less
+exceptional organic circumstance. These variations may be momentary and
+transient or comparatively permanent. The illusion arises in each case
+from our ignoring the variation, and treating a given sensation under
+all circumstances as answering to one objective cause.
+
+First of all, the variation of organic state may affect our mental
+representation of the strength of the stimulus or external cause. Here
+the fluctuation may be a temporary or a permanent one. The first case is
+illustrated in the familiar example of taking a room to be brighter
+than it is when emerging from a dark one. Another striking example is
+that of our sense of the temperature of objects, which is known to be
+strictly relative to a previous sensation, or more correctly to the
+momentary condition of the organ. Yet, though every intelligent person
+knows this, the deeply rooted habit of making sensation the measure of
+objective quality asserts its sway, and frequently leads us into
+illusion. The well-known experiment of first plunging one hand in cold
+water, the other in hot, and then dipping them both in tepid, is a
+startling example of this organized tendency. For here we are strongly
+disposed to accept the palpable contradiction that the same water is at
+once warm and cool.
+
+Far more important than these temporary fluctuations of sensibility are
+the permanent alterations. Excessive fatigue, want of proper nutrition,
+and certain poisons are well known to be causes of such changes. They
+appear most commonly under two forms, exalted sensibility, or
+hyperaesthesia, and depressed sensibility, or anaesthesia. In these
+conditions flagrant errors are made as to the real magnitude of the
+causes of the sensations. These variations may occur in normal life to
+some extent. In fairly good health we experience at times strange
+exaltations of tactual sensibility, so that a very slight stimulus, such
+as the contact of the bed-clothes, becomes greatly exaggerated.
+
+In diseased states of the nervous system these variations of sensibility
+become much more striking. The patient who has hyperaesthesia fears to
+touch a perfectly smooth surface, or he takes a knock at the door to be
+a clap of thunder. The hypochondriac may, through an increase of
+organic sensibility, translate organic sensations as the effect of some
+living creature gnawing at his vitals. Again, states of anaesthesia lead
+to odd illusions among the insane. The common supposition that the body
+is dead, or made of wood or of glass, is clearly referable in part to
+lowered sensibility of the organism.[32]
+
+It is worth adding, perhaps, that these variations in sensibility give
+rise not only to sensory but also to motor illusions. To take a homely
+instance, the last miles of a long walk seem much longer than the first,
+not only because the sense of fatigue leading us to dwell on the
+transition of time tends to magnify the apparent duration, but because
+the fatigued muscles and connected nerves yield a new set of sensations
+which constitute an exaggerated standard of measurement. A number of
+optical illusions illustrate the same thing. Our visual sense of
+direction is determined in part by the feelings accompanying the action
+of the ocular muscles, and so is closely connected with the perception
+of movement, which has already been touched on. If an ocular muscle is
+partially paralyzed it takes a much greater "effort" to effect a given
+extent of movement than when the muscle is sound. Hence any movement
+performed by the eye seems exaggerated. Hence, too, in this condition
+objects are seen in a wrong direction; for the patient reasons that they
+are where they would seem to be if he had executed a wider movement than
+he really has. This may easily be proved by asking him to try to seize
+the object with, his hand. The effect is exaggerated when complete
+paralysis sets in, and no actual movement occurs in obedience to the
+impulse from within.[33]
+
+Variations in the condition of the nerve affect not only the degree, but
+also the quality of the sensation, and this fact gives rise to a new
+kind of illusion. The curious phenomena of colour-contrast illustrate
+momentary alterations of sensibility. When, after looking at a green
+colour for a time, I turn my eye to a grey surface and see this of the
+complementary rose-red hue, the effect is supposed to be due to a
+temporary fatigue of the retina in relation to those ingredients of the
+total light in the second case which answer to the partial light in the
+first (the green rays).[34]
+
+These momentary modifications of sensibility are of no practical
+significance, being almost instantly corrected. Other modifications are
+more permanent. It was found by Himly that when the retina is
+overexcitable every stimulus is raised in the spectrum scale of colours.
+Thus, violet becomes red. An exactly opposite effect is observed when
+the retina is torpid.[35] Certain poisons are known to affect the
+quality of the colour-impression. Thus, santonin, when taken in any
+quantity, makes all colourless objects look yellow. Severe pathological
+disturbances are known to involve, in addition to hyperaesthesia and
+anaesthesia, what, has been called paraesthesia, that is to say, that
+condition in which the quality of sensation is greatly changed. Thus,
+for example, to one in this state all food appears to have a metallic
+taste, and so on.
+
+If we now glance back at the various groups of illusions just
+illustrated, we find that they all have this feature in common: they
+depend on the general mental law that when we have to do with the
+unfrequent, the unimportant, and therefore unattended to, and the
+exceptional, we employ the ordinary, the familiar, and the well-known as
+our standard. Thus, whether we are dealing with sensations that fall
+below the ordinary limits of our mental experience, or with those which
+arise in some exceptional state of the organism, we carry the habits
+formed in the much wider region of average every-day perception with us.
+In a word, illusion in these cases always arises through what may,
+figuratively at least, be described as the application of a rule, valid
+for the majority of cases, to an exceptional case.
+
+In the varieties of illusion just considered, the circumstance that
+gives the peculiarity to the case thus wrongly interpreted has been
+referred to the organism. In the illusions to which we now pass, it will
+be referred to the environment. At the same time, it is plain that there
+is no very sharp distinction between the two classes. Thus, the visual
+illusion produced by pressing the eyeball might be regarded not only as
+the result of the organic law of the "specific energy" of the nerves,
+but, with almost equal appropriateness, as the consequence of an
+exceptional state of things in the environment, namely, the pressure of
+a body on the retina. As I have already observed, the classification
+here adopted is to be viewed simply as a rough expedient for securing
+something like a systematic review of the phenomena.
+
+
+
+
+CHAPTER V.
+
+ILLUSIONS OF PERCEPTION--_continued_.
+
+A. _Passive Illusions (b) as determined by the Environment._
+
+
+In the following groups of illusion we may look away from nervous
+processes and organic disturbances, regarding the effect of any external
+stimulus as characteristic, that is, as clearly marked off from the
+effects of other stimuli, and as constant for the same stimulus. The
+source of the illusion will be looked for in something exceptional in
+the external circumstances, whereby one object or condition of an object
+imitates the effect of another object or condition, to which, owing to a
+large preponderance of experience, we at once refer it.
+
+
+_Exceptional Relation of Stimulus to Organ._
+
+A transition from the preceding to the following class of illusions is
+to be met with in those errors which arise from a very exceptional
+relation between the stimulus and the organ of sense. Such a state of
+things is naturally interpreted by help of more common and familiar
+relations, and so error arises.
+
+For example, we may grossly misinterpret the intensity of a stimulus
+under certain circumstances. Thus, when a man crunches a biscuit, he has
+an uncomfortable feeling that the noise as of all the structures of his
+head being violently smashed is the same to other ears, and he may even
+act on his illusory perception, by keeping at a respectful distance from
+all observers. And even though he be a physiologist, and knows that the
+force of sensation in this case is due to the propagation of vibrations
+to the auditory centre by other channels than the usual one of the ear,
+the deeply organized impulse to measure the strength of an external
+stimulus by the intensity of the sensation asserts its force.
+
+Again, if we turn to the process of perceptional construction properly
+so called, the reference of the sensation to a material object lying in
+a certain direction, etc., we find a similar transitional form of
+illusion. The most interesting case of this in visual perception is that
+of a disturbance or displacement of the organ by external force. For
+example, an illusory sense of direction arises by the simple action of
+closing one eye, say the left, and pressing the other eyeball with one
+of the fingers a little outwards, that is to the right. The result of
+this movement is, of course, to transfer the retinal picture to new
+nervous elements further to the right. And since, in this instance, the
+displacement is not produced in the ordinary way by the activity of the
+ocular muscle making itself known by certain feelings of movement, it is
+disregarded altogether, and the direction of the objects is judged as
+though the eye were stationary.
+
+A somewhat similar illusion as to direction occurs in auditory
+perception. The sense of direction by the ear is known to be due in part
+to the action of the auricle, or projecting part of the ear. This
+collects the air-waves, and so adds to the intensity of the sounds,
+especially those coming from in front, and thus assists in the
+estimation of direction. This being so, if an artificial auricle is
+placed in front of the ears; if, for example, the two hands are each
+bent into a sort of auricle, and placed in front of the ears, the back
+of the hand being in front, the sense of direction (as well as of
+distance) is confused. Thus, sounds really travelling from a point in
+front of the head will appear to come from behind it.
+
+Again, the perception of the unity of an object is liable to be
+falsified by the introduction of exceptional circumstances into the
+sense-organ. This is illustrated in the well-known experiment of
+crossing two fingers, say the third and fourth, and placing a marble or
+other small round object between them. Under ordinary circumstances, the
+two lateral surfaces (that is, the outer surfaces of the two fingers)
+now pressed by the marble, can only be acted on simultaneously by _two_
+objects having convex surfaces. Consequently, we cannot help feeling the
+presence of two objects in this exceptional instance. The illusion is
+analogous to that of the stereoscope, to be spoken of presently.
+
+
+_Exceptional External Arrangements._
+
+Passing now to those cases where the exceptional circumstance is
+altogether exterior to the organ, we find a familiar example in the
+illusions connected with the action of well-known physical forces, as
+the refraction of light, and the reflection of light and sound. A stick
+half-immersed in water always _looks_ broken, however well we may know
+that the appearance is due to the bending of the rays of light.
+Similarly, an echo always sounds as though it came from some object in
+the direction in which the air-waves finally travel to the ear, though
+we are perfectly sure that these undulations have taken a circuitous
+course. It is hardly necessary to remind the reader that the deeply
+organized tendency to mistake the direction of the visible or audible
+object in these cases has from remote ages been made use of as a means
+of popular delusion. Thus, we are told by Sir D. Brewster, in his
+entertaining _Letters on Natural Magic_ (letter iv.), that the concave
+mirror was probably used as the instrument for bringing the gods before
+the people. The throwing of the images formed by such mirrors upon smoke
+or against fire, so as to make them more distinct, seems to have been a
+favourite device in the ancient art of necromancy.
+
+Closely connected with these illusions of direction with respect to
+resting objects, are those into which we are apt to fall respecting the
+movements of objects. What looks like the movement of something across
+the field of vision is made known to us either by the feeling of the
+ocular muscles, if the eye follows the object, or through the sequence
+of locally distinct retinal impressions, if the eye is stationary. Now,
+either of these effects may result, not only from the actual movement of
+the object in a particular direction, but from our own movement in an
+opposite direction; or, again, from our both moving in the first
+direction, the object more rapidly than ourselves; or, finally, from our
+both moving in an opposite direction to this, ourselves more rapidly
+than the object. There is thus always a variety of conceivable
+explanations, and the action of past experience and association shows
+itself very plainly in the determination of the direction of
+interpretation. Thus, it is our instinctive tendency to take apparent
+movement for real movement, except when the fact of our own movement is
+clearly present to consciousness, as when we are walking, or when we are
+sitting behind a horse whose movement we see. And so when the sense of
+our own movement becomes indistinct, as in a railway carriage, we
+naturally drift into the illusion that objects, such as trees, telegraph
+posts, and so on, are moving, when they are perfectly still. Under the
+same circumstances, we are apt to suppose that a train which is just
+shooting ahead of us is moving slowly.
+
+Similar uncertainties arise with respect to the relative movement of two
+objects, the eye being supposed to be fixed in space. When two objects
+seem to pass one another, it may be that they are both moving in
+contrary directions, or that one only is moving, or finally, that both
+are moving in the same direction, the one faster than the other.
+Experience and habit here again suggest the interpretation which is most
+easy, and not unfrequently produce illusion. Thus, when we watch clouds
+scudding over the face of the moon, the latter seems moving rather than
+the former, and the illusion only disappears when we fix the eye on the
+moon and recognize that it is really stationary. The probable reason of
+this is, as Wundt suggests, that experience has made it far easier for
+us to think of small objects like the moon moving rapidly, than of large
+masses like the clouds.[36]
+
+The perception of distance, still more than that of direction, is liable
+to be illusory. Indeed, the visual recognition of distance, together
+with that of solidity, has been the great region for the study of "the
+deceptions of the senses." Without treating the subject fully here, I
+shall try to describe briefly the nature and source of these
+illusions.[37]
+
+Confining ourselves first of all to near objects, we know that the
+smaller differences of distance in these cases are, if the eyes are at
+rest, perceived by means of the dissimilar pictures projected on the two
+retinas; or if they move, by this means, together with the muscular
+feelings that accompany different degrees of convergence of the two
+eyes. This was demonstrated by the famous experiments of Wheatstone.
+Thus, by means of the now familiar stereoscope, he was able to produce a
+perfect illusion of relief. The stereoscope may be said to introduce an
+exceptional state of things into the spectator's environment. It
+imitates, by means of two flat drawings, the dissimilar retinal pictures
+projected by a single solid receding object, and the lenses through
+which the eyes look are so constructed as to compel them to converge as
+though looking on a single object. And so powerful is the tendency to
+interpret this impression as one of solidity, that even though we are
+aware of the presence of the stereoscopic apparatus, we cannot help
+seeing the two drawings as a single solid object.
+
+In the case of more remote objects, there is no dissimilarity of the
+retinal pictures or feelings of convergence to assist the eye in
+determining distance. Here its judgment, which now becomes more of a
+process of _conscious_ inference, is determined by a number of
+circumstances which, through experience and association, have become the
+signs of differences of depth in space. Among these are the degree of
+indistinctness of the impression, the apparent or retinal magnitude (if
+the object is a familiar one), the relations of linear perspective, as
+the interruption of the outline of far objects by that of near objects,
+and so on. In a process so complicated there is clearly ample room for
+error, and wrong estimates of distance whenever unusual circumstances
+are present are familiar to all. Thus, the inexperienced English
+tourist, when in the clear atmosphere of Switzerland, where the
+impressions from distant objects are more distinct than at home,
+naturally falls into the illusion that the mountains are much nearer
+than they are, and so fails to realize their true altitude.
+
+_Illusions of Art._
+
+The imitation of solidity and depth by art is a curious and interesting
+illustration of the mode of production of illusion. Here we are not, of
+course, concerned with the question how far illusion is desirable in
+art, but only with its capabilities of illusory presentment; which
+capabilities, it may be added, have been fully illustrated in the
+history of art. The full treatment of this subject would form a chapter
+in itself; here I can only touch on its main features.
+
+Pictorial art working on a flat surface cannot, it is plain, imitate the
+stereoscope, and produce a perfect sense of solidity. Yet it manages to
+produce a pretty strong illusion. It illustrates in a striking manner
+the ease with which the eye conceives relations of depth or relief and
+solidity. If, for example, on a carpet, wall-paper, or dress, bright
+lines are laid on a dark colour as ground, we easily imagine that they
+are advancing. The reason of this seems to be that in our daily
+experience advancing surfaces catch and reflect the light, whereas
+retiring surfaces are in shadow.[38]
+
+The same principle is illustrated in one of the means used by the artist
+to produce a strong sense of relief, namely, the cast shadow. A circle
+drawn with chalk with a powerful cast shadow on one side will, without
+any shading or modelling of the form, appear to stand out from the
+paper, thus:
+
+[Illustration: FIG. 1.]
+
+The reason is that the presence of such a shadow so forcibly suggests to
+the mind that the object is a prominent one intervening between the
+light and the shaded surface.[39]
+
+Even without differences of light and shade, by a mere arrangement of
+lines, we may produce a powerful sense of relief or solidity. A striking
+example of this is the way in which two intersecting lines sometimes
+appear to recede from the eye, as the lines _a a'_, _b b'_, in the next
+drawing, which seem to belong to a regular pattern on the ground, at
+which the eye is looking from above and obliquely.
+
+[Illustration: FIG. 2.]
+
+Again, the correct delineation of the projection of a regular
+geometrical figure, as a cube, suffices to give the eye a sense of
+relief. This effect is found to be the more striking in proportion to
+the familiarity of the form. The following drawing of a long box-shaped
+solid at once seems to stand out to the eye.
+
+[Illustration: FIG. 3.]
+
+This habitual interpretation of the flat in art as answering to objects
+in relief, or having depth, can only be understood when it is remembered
+that our daily experience gives us myriads of instances in which the
+effect of such flat representations answers to solid receding forms.
+That is to say, in the case of all distant objects, in the perception of
+which the dissimilarity of the retinal pictures and the feeling of
+convergence take no part, we have to interpret solidity, and relations
+of nearer and further, by such signs as linear perspective and cast
+shadow. On the other hand, it is only in the artificial life of indoors,
+on our picture-covered walls, that we experience such effects without
+discovering corresponding realities. Hence a deeply organized habit of
+taking these impressions as answering to the solid and not to the flat.
+If our experience had been quite different; if, for example, we had
+been brought up in an empty room, amid painted walls, and had been
+excluded from the sight of the world of receding objects outside, we
+might easily have formed an exactly opposite habit of taking the actual
+mountains, trees, etc., of the distant scene to be pictures laid on a
+flat surface.
+
+[Illustration: FIG. 4.]
+
+It follows from this that, with respect to the distant parts of a scene,
+pictorial art possesses the means of perfect imitation; and here we see
+that a complete illusory effect is obtainable. I need but to refer to
+the well-known devices of linear and aerial perspective, by which this
+result is secured.[40] The value of these means of producing illusion at
+the command of the painter, may be illustrated by the following fact,
+which I borrow from Helmholtz. If you place two pieces of cardboard
+which correspond to portions of one form at the sides and in front of a
+third piece, in the way represented above, so as just to allow the eye
+to follow the contour of this last, and then look at this arrangement
+from a point at some little distance with one eye, you easily suppose
+that it stands in front of the side pieces. The explanation of the
+illusion is that this particular arrangement powerfully suggests that
+the outline of the whole figure, of which the two side pieces are parts,
+is broken by an intervening object. Owing to the force of these and
+other suggestions, it is easy for the spectator, when attending to the
+background of a landscape painting, to give himself up for a moment to
+the pleasant delusion that he is looking at an actual receding scene.
+
+In connection with pictorial delusion, I may refer to the well-known
+fact, that the eye in a portrait seems to follow the spectator, or that
+a gun, with its muzzle pointing straight outwards, appears to turn as
+the spectator moves.[41] These tricks of art have puzzled many people,
+yet their effect is easily understood, and has been very clearly
+explained by Sir D. Brewster, in the work already referred to (letter
+v.). They depend on the fact that a painting, being a flat projection
+only and not a solid, continues to present the front view of an object
+which it represents wherever the spectator happens to stand. Were the
+eye in the portrait a real eye, a side movement of the spectator would,
+it is evident, cause him to see less of the pupil and more of the side
+of the eyeball, and he would only continue to see the full pupil when
+the eye followed him. We regard the eye in the picture as a real eye
+having relief, and judge accordingly.
+
+We may fall into similar illusions respecting distance in auditory
+perception. A change of wind, an unusual stillness in the air, is quite
+sufficient to produce the sense that sounding objects are nearer than
+they actually are. The art of the ventriloquist manifestly aims at
+producing this kind of illusion. By imitating the dull effect of a
+distant voice, he is able to excite in the minds of his audience a
+powerful conviction that the sounds proceed from a distant point. There
+is little doubt that ventriloquism has played a conspicuous part in the
+arts of divination and magic.
+
+
+_Misconception of Local Arrangement._
+
+Let us now pass to a class of illusions closely related to those having
+to do with distance, but involving some special kind of circumstance
+which powerfully suggests a particular arrangement in space. One of the
+most striking examples of these is the erroneous localization of a
+quality in space, that is to say, the reference of it to an object
+nearer, or further off than the right one. Thus, when we look through a
+piece of yellow glass at a dull, wintry landscape, we are disposed to
+imagine that we are looking at a sunny scene of preternatural warmth. A
+moment's reflection would tell us that the yellow tint, with which the
+objects appear to be suffused, comes from the presence of the glass;
+yet, in spite of this, the illusion persists with a curious force. The
+explanation is, of course, that the circumstances are exceptional, that
+in a vast majority of cases the impression of colour belongs to the
+object and not to an intervening medium,[42] and that consequently we
+tend to ignore the glass, and to refer the colour to the objects
+themselves.
+
+When, however, the fact of the existence of a coloured medium is
+distinctly present to the mind, we easily learn to allow for this, and
+to recognize one coloured surface correctly through a recognized medium.
+Thus, we appear to ourselves to see the reflected images of the wall,
+etc., of a room, in a bright mahogany table, not suffused with a reddish
+yellow tint, as they actually are--and may be seen to be by the simple
+device of looking at a small bit of the image through a tube, but in
+their ordinary colour. We may be said to fall into illusion here in so
+far as we overlook the exact quality of the impression actually made on
+the eye. This point will be touched on presently. Here I am concerned to
+show that this habit of allowing for the coloured medium may, in its
+turn, occasionally lead to plain and palpable illusion.
+
+The most striking example of this error is to be met with among the
+curious phenomena of colour-contrast already referred to. In many of
+these cases the appearance of the contrasting colour is, as I have
+observed, due to a temporary modification of the nervous substance. Yet
+it is found that this organic factor does not wholly account for the
+phenomena. For example, Meyer made the following experiment. He covered
+a piece of green paper by a sheet of thin transparent white paper. The
+colour of this double surface was, of course, a pale green. He then
+introduced a scrap of grey paper between the two sheets, and found that,
+instead of looking whitish as it really was, it looked rose-red.
+Whatever the colour of the under sheet the grey scrap took the
+complementary hue. If, however, the piece of grey paper is put outside
+the thin sheet, it looks grey; and what is most remarkable is that when
+a second piece is put outside, the scrap inside no longer wears the
+complementary hue.
+
+There is here evidently something more than a change of organic
+conditions; there is an action of experience and suggestion. The reason
+of our seeing the scrap rose-red in one case and neutral grey in
+another, is that in the first instance we vividly represent to ourselves
+that we are looking at it through a greenish veil (which is, of course,
+a part of the illusion); for rose-red seen through a greenish medium
+would, as a matter of fact, be light grey, as this scrap is. Even if we
+allow that there always exists after an impression of colour a temporary
+organic disposition to see the complementary hue, this does not suffice
+as an explanation of these cases; we have to conclude further that
+imagination, led by the usual run of our experience, is here a
+co-operant factor, and helps to determine whether the complementary tint
+shall be seen or not.
+
+
+_Misinterpretation of Form._
+
+More complex and circumscribed associations take part in those errors
+which we occasionally commit respecting the particular form of objects.
+This has already been touched on in dealing with artistic illusion. The
+disposition of the eye to attribute solidity to a flat drawing is the
+more powerful in proportion to the familiarity of the form. Thus, an
+outline drawing of a building is apt to stand out with special force.
+
+Another curious illustration of this is the phenomenon known as the
+conversion of the concave mould or matrix of a medal into the
+corresponding convex relief. If, says Helmholtz, the mould of a medal be
+illuminated by a light falling obliquely so as to produce strong
+shadows, and if we regard this with one eye, we easily fall into the
+illusion that it is the original raised design, illuminated from _the
+opposite side_. As a matter of fact, the visual impression produced by a
+concave form with the light falling on one side, very closely resembles
+that produced by a corresponding convex form with the light falling on
+the other side. At the same time, it is found that the opposite mode of
+conversion, that is to say, the transformation of the raised into the
+depressed form, though occurring occasionally, is much less frequent.
+Now, it may be asked, why should we tend to transform the concave into
+the convex, rather than the convex into the concave? The reader may
+easily anticipate the answer from what has been said about the deeply
+fixed tendency of the eye to solidify a plane surface. We are rendered
+much more familiar, both by nature and by art, with raised (_cameo_)
+design than with depressed design (_intaglio_), and we instinctively
+interpret the less familiar form by the more familiar. This explanation
+appears to be borne out by the fact emphasized by Schroeder that the
+illusion is much more powerful if the design is that of some well-known
+object, as the human head or figure, or an animal form, or leaves.[43]
+
+Another illustration of this kind of illusion recently occurred in my
+own experience. Nearly opposite to my window came a narrow space between
+two detached houses. This was, of course, darker than the front of the
+houses, and the receding parallel lines of the bricks appeared to cross
+this marrow vertical shaft obliquely. I could never look at this without
+seeing it as a convex column, round which the parallel lines wound
+obliquely. Others saw it as I did, though not always with the same
+overpowering effect. I can only account for this illusion by help of the
+general tendency of the eye to solidify impressions drawn from the flat,
+together with the effect of special types of experience, more
+particularly the perception of cylindrical forms in trees, columns, etc.
+
+It may be added that a somewhat similar illustration of the action of
+special types of experience on the perception of individual form may be
+found in the region of hearing. The powerful disposition to take the
+finely graduated cadences of sound produced by the wind for the
+utterances of a Iranian voice, is due to the fact that this particular
+form and arrangement of sound has deeply impressed itself on our minds,
+in connection with numberless utterances of human feeling.
+
+_Illusions of Recognition._
+
+As a last illustration of comparatively passive illusions, I may refer
+to the errors which we occasionally commit in recognizing objects. As I
+have already observed, the process of full and clear recognition,
+specific and individual, involves a classing of a number of distinct
+aspects of the object, such as colour, form, etc. Accordingly, when in a
+perfectly calm state of mind we fall into illusion with respect to any
+object plainly visible, it must be through some accidental resemblance
+between the object and the other object or class of objects with which
+we identify it. In the case of individual identification such illusions
+are, of course, comparatively rare, since here there are involved so
+many characteristic differences. On the other hand, in the case of
+specific recognition there is ample room for error, especially in those
+kinds of more subtle recognition to which I have already referred. To
+"recognize" a person as a Frenchman or a military man, for example, is
+often an erroneous process. Logicians have included this kind of error
+under what they call "fallacies of observation."
+
+Errors of recognition, both specific and individual, are, of course,
+more easy in the case of distant objects or objects otherwise
+indistinctly seen. It is noticeable in these cases that, even when
+perfectly cool and free from emotional excitement, we tend to interpret
+such indistinct impressions according to certain favourite types of
+experience, as the human face and figure. Our interpretative imagination
+easily sees traces of the human form in cloud, rock, or tree-stump.
+
+Again, even when there is no error of recognition, in the sense of
+confusing one object with other objects, there may be partial illusion.
+I have remarked that the process of recognizing an object commonly
+involves an overlooking of points of diversity in the object, or aspect
+of the object, now present. And sometimes this inattention to what is
+actually present includes an error as to the actual visual sensation of
+the moment. Thus, for example, when I look at a sheet of white paper in
+a feebly lit room, I seem to see its whiteness. If, however, I bring it
+near the window, and let the sun fall on a part of it, I at once
+recognize that what I have been seeing is not white, but a decided grey.
+Similarly, when I look at a brick viaduct a mile or two off, I appear to
+myself to recognize its redness. In fact, however, the impression of
+colour which I receive from the object is not that of brick-red at all,
+but a much less decided tint; which I may easily prove by bending my
+head downwards and letting the scene image itself on the retina in an
+unusual way, in which case the recognition of the object as a viaduct
+being less distinct, I am better able to attend to the exact shade of
+the colour.
+
+Nowhere is this inattention to the sensation of the moment exhibited in
+so striking a manner as in pictorial art. A picture of Meissonier may
+give the eye a representation of a scene in which the objects, as the
+human figures and horses, have a distinctness that belongs to near
+objects, but an apparent magnitude that belongs to distant objects. So
+again, it is found that the degree of luminosity or brightness of a
+pictorial representation differs in general enormously from that of the
+actual objects. Thus, according to the calculations of Helmholtz,[44] a
+picture representing a Bedouin's white raiment in blinding sunshine,
+will, when seen in a fairly lit gallery, have a degree of luminosity
+reaching only to about one-thirtieth of that of the actual object. On
+the other hand, a painting representing marble ruins illuminated by
+moonlight, will, under the same conditions of illumination, have a
+luminosity amounting to as much as from ten to twenty thousand times
+that of the object. Yet the spectator does not notice these stupendous
+discrepancies. The representation, in spite of its vast difference, at
+once carries the mind on to the actuality, and the spectator may even
+appear to himself, in moments of complete absorption, to be looking at
+the actual scene.
+
+The truly startling part of these illusions is, that the direct result
+of sensory stimulation appears to be actually displaced by a mental
+image. Thus, in the case of Meyer's experiment, of looking at the
+distant viaduct, and of recognizing an artistic representation,
+imagination seems in a measure to take the place of sensation, or to
+blind the mind to what is actually before it.
+
+The mystery of the process, however, greatly disappears when it is
+remembered that what we call a conscious "sensation" is really
+compounded of a result of sensory stimulation and a result of central
+reaction, of a purely passive impression and the mental activity
+involved in attending to this and classing it.[45] This being so, a
+sensation may be modified by anything exceptional in the mode of central
+reaction of the moment. Now, in all the cases just considered, we have
+one common feature, a powerful suggestion of the presence of a
+particular object or local arrangement. This suggestion, taking the form
+of a vivid mental image, dominates and overpowers the passive
+impression. Thus, in Meyer's experiment, the mind is possessed by the
+supposition that we are looking at the grey spot through a greenish
+medium. So in the case of the distant viaduct, we are under the mastery
+of the idea that what we see in the distance is a red brick structure.
+Once more, in the instance of looking at the picture, the spectator's
+imagination is enchained by the vivid representation of the object for
+which the picture stands, as the marble ruins in the moonlight or the
+Bedouin in the desert.
+
+It may be well to add that this mental uncertainty as to the exact
+nature of a present impression is necessitated by the very conditions of
+accurate perception. If, as I have said, all recognition takes place by
+overlooking points of diversity, the mind must, in course of time,
+acquire a habit of not attending to the exact quality of
+sense-impressions in all cases where the interpretation seems plain and
+obvious. Or, to use Helmholtz's words, our sensations are, in a general
+way, of interest to us only as signs of things, and if we are sure of
+the thing, we readily overlook the precise nature of the impression. In
+short, we get into the way of attending only to what is essential,
+constant, and characteristic in objects, and disregarding what is
+variable and accidental.[46] Thus, we attend, in the first place, to the
+form of objects, the most constant and characteristic element of all,
+being comparatively inattentive to colour, which varies with distance,
+atmospheric changes, and mode of illumination. So we attend to the
+relative magnitude of objects rather than to the absolute, and to the
+relative intensities of light and shade rather than to the absolute; for
+in so doing we are noting what is constant for all distances and modes
+of illumination, and overlooking what is variable. And the success of
+pictorial art depends on the observance of this law of perception.
+
+These remarks at once point out the limits of these illusions. In normal
+circumstances, an act of imagination, however vivid, cannot create the
+semblance of a sensation which is altogether absent; it can only
+slightly modify the actual impression by interfering with that process
+of comparison and classification which enters into all definite
+determination of sensational quality.
+
+Another great fact that has come to light in the investigation of these
+illusions is that oft-recurring and familiar types of experience leave
+permanent dispositions in the mind. As I said when describing the
+process of perception, what has been frequently perceived is perceived
+more and more readily. It follows from this that the mind will be
+habitually disposed to form the corresponding mental images, and to
+interpret impressions by help of these. The range of artistic suggestion
+depends on this. A clever draughtsman can indicate a face by a few rough
+touches, and this is due to the fact that the spectator's mind is so
+familiarized, through recurring experience and special interest, with
+the object, that it is ready to construct the requisite mental image at
+the slightest external suggestion. And hence the risk of hasty and
+illusory interpretation.
+
+These observations naturally conduct us to the consideration of the
+second great group of sense-illusions, which I have marked off as active
+illusions, where the action of a pre-existing intellectual disposition
+becomes much more clearly marked, and assumes the form of a free
+imaginative transformation of reality.
+
+
+
+
+CHAPTER VI.
+
+ILLUSIONS OF PERCEPTION--_continued_.
+
+B. _Active Illusions._
+
+
+When giving an account of the mechanism of perception, I spoke of an
+independent action of the imagination which tends to anticipate the
+process of suggestion from without. Thus, when expecting a particular
+friend, I recognize his form much more readily than when my mind has not
+been preoccupied with his image.
+
+A little consideration will show that this process must be highly
+favourable to illusion. To begin with, even if the preperception be
+correct, that is to say, if it answer to the perception, the mere fact
+of vivid expectation will affect the exact moment of the completed act
+of perception. And recent experiment shows that in certain cases such a
+previous activity of expectant attention may even lead to the illusory
+belief that the perception takes place before it actually does.[47]
+
+A more palpable source of error resides in the risk of the formation of
+an inappropriate preperception. If a wrong mental image happens to have
+been formed and vividly entertained, and if the actual impression fits
+in to a certain extent with this independently formed preperception, we
+may have a fusion of the two which exactly simulates the form of a
+complete percept. Thus, for example, in the case just supposed, if
+another person, bearing some resemblance to our expected friend, chances
+to come into view, we may probably stumble into the error of taking one
+person for another.
+
+On the physical side, we may, agreeably to the hypothesis mentioned
+above, express this result by saying that, owing to a partial identity
+in the nervous processes involved in the anticipatory image and the
+impression, the two tend to run one into the other, constituting one
+continuous process.
+
+There are different ways in which this independent activity of the
+imagination may falsify our perceptions. Thus, we may voluntarily choose
+to entertain a certain image for the moment, and to look at the
+impression in a particular way, and within certain limits such
+capricious selection of an interpretation is effectual in giving a
+special significance to an impression. Or the process of independent
+preperception may go on apart from our volitions, and perhaps in spite
+of these, in which case the illusion has something of the irresistible
+necessity of a passive illusion. Let us consider separately each mode
+of production.
+
+
+_Voluntary Selection of Interpretation._
+
+The action of a capricious exercise of the imagination in relation to an
+impression is illustrated in those cases where experience and suggestion
+offer to the interpreting mind an uncertain sound, that is to say, where
+the present sense-signs are ambiguous. Here we obviously have a choice
+of interpretation. And it is found that, in these cases, what we see
+depends very much on what we wish to see. The interpretation adopted is
+still, in a sense, the result of suggestion, but of one particular
+suggestion which the fancy of the moment determines. Or, to put it
+another way, the caprice of the moment causes the attention to focus
+itself in a particular manner, to direct itself specially to certain
+aspects and relations of objects.
+
+The eye's interpretation of movement, already referred to, obviously
+offers a wide field for this play of selective imagination. When looking
+out of the window of a railway carriage, I can at will picture to my
+mind the trees and telegraph posts as moving objects. Sometimes the true
+interpretation is so uncertain that the least inclination to view the
+phenomenon in one way determines the result. This is illustrated in a
+curious observation of Sinsteden. One evening, on approaching a windmill
+obliquely from one side, which under these circumstances he saw only as
+a dark silhouette against a bright sky, he noticed that the sails
+appeared to go, now in one direction, now in another, according as he
+imagined himself looking at the front or at the back of the
+windmill.[48]
+
+In the interpretation of geometrical drawings, as those of crystals,
+there is, as I have observed, a general tendency to view the flat
+delineation as answering to a raised object, or a body in relief,
+according to the common run of our experience. Yet there are cases where
+experience is less decided, and where, consequently, we may regard any
+particular line as advancing or receding. And it is found that when we
+vividly imagine that the drawing is that of a convex or concave surface,
+we see it to be so, with all the force of a complete perception. The
+least disposition to see it in the other way will suffice to reverse the
+interpretation. Thus, in the following drawing, the reader can easily
+see at will something answering to a truncated pyramid, or to the
+interior of a cooking vessel.
+
+[Illustration: FIG. 5.]
+
+Similarly, in the accompanying figure of a transparent solid, I can at
+will select either of the two surfaces which approximately face the eye
+and regard it as the nearer, the other appearing as the hinder surface
+looked at through the body.
+
+[Illustration: FIG. 6.]
+
+Again, in the next drawing, taken from Schroeder, one may, by an effort
+of will, see the diagonal step-like pattern, either as the view from
+above of the edge of an advancing piece of wall at _a_, or as the view
+from below of the edge of an advancing (overhanging) piece of wall at
+_b_.
+
+[Illustration: FIG. 7.]
+
+These last drawings are not in true perspective on either of the
+suppositions adopted, wherefore the choice is easier. But even when an
+outline form is in perspective, a strenuous effort of imagination may
+suffice to bring about a conversion of the appearance. Thus, if the
+reader will look at the drawing of the box-like solid (Fig. 3, p. 79),
+he will find that, after a trial or two, he succeeds in seeing it as a
+_concave_ figure representing the coyer and two sides of a box as looked
+at from within.[49]
+
+Many of my readers, probably, share in my power of variously
+interpreting the relative position of bands or stripes on fabrics such
+as wall-papers, according to wish. I find that it is possible to view
+now this stripe or set of stripes as standing out in relief upon the
+others as a ground, now these others as advancing out of the first as a
+background. The difficulty of selecting either interpretation at will
+becomes greater, of course, in those cases where there is a powerful
+suggestion of some particular local arrangement, as, for example, the
+case of patterns much brighter than the ground, and especially of such
+as represent known objects, as flowers. Yet even here a strong effort of
+imagination will often suffice to bring about a conversion of the first
+appearance.
+
+A somewhat similar choice of interpretation offers itself in looking at
+elaborate decorative patterns. When we strongly imagine any number of
+details to be elements of one figure, they seem to become so; and a
+given detail positively appears to alter in character according as it is
+viewed as an element of a more or less complex figure.
+
+These examples show what force belongs to a vivid preconception, if this
+happens to fit only very roughly the impression of the moment, that is
+to say, if the interpretative image is one of the possible suggestions
+of the impression. The play of imagination takes a wider range in those
+cases where the impression is very indefinite in character, easily
+allowing of a considerable variety of imaginative interpretation.
+
+I referred at the beginning of this account of sense-illusions to the
+readiness with which the mind deceives itself with respect to the nature
+and causes of the vague sensations which usually form the dim background
+of our mental life. A person of lively imagination, by trying to view
+these in a particular way, and by selectively attending to those aspects
+of the sensation which answer to the caprice of the moment, may give a
+variety of interpretations to one and the same set of sensations. For
+example, it is very easy to get confused with respect to those tactual
+and motor feelings which inform us of the position of our bodily
+members. And so, when lying in bed, and attending to the sensations
+connected with the legs, we may easily delude ourselves into supposing
+that these members are arranged in a most eccentric fashion. Similarly,
+by giving special heed to the sensations arising in connection with the
+condition of the skin at any part, we may amuse ourselves with the
+strangest fancies as to what is going on in these regions.
+
+Again, when any object of visual perception is indistinct or indefinite
+in form, there is plainly an opening for this capricious play of fancy
+in transforming the actual. This is illustrated in the well-known
+pastime of discovering familiar forms, such as those of the human head
+and animals, in distant rocks and clouds, and of seeing pictures in the
+fire, and so on. The indistinct and indefinite shapes of the masses of
+rock, cloud, or glowing coal, offer an excellent field for creative
+fancy, and a person of lively imagination will discover endless forms in
+what, to an unimaginative eye, is a formless waste. Johannes Mueller
+relates that, when a child, he used to spend hours in discovering the
+outlines of forms in the partly blackened and cracked stucco of the
+house that stood opposite to his own.[50] Here it is plain that, while
+experience and association are not wholly absent, but place certain wide
+limits on this process of castle-building, the spontaneous activity of
+the percipient mind is the great determining force.
+
+So much as to the influence of a perfectly unfettered voluntary
+attention on the determination of the stage of preperception, and,
+through this, of the resulting interpretation. Let us now pass to cases
+in which this direction of preperception follows not the caprice of the
+moment, but the leading of some fixed predisposition in the
+interpreter's mind. In these cases attention is no longer free, but
+fettered, only it is now fettered rather from within than from without;
+that is to say, the dominating preperception is much more the result of
+an independent bent of the imagination than of some suggestion forced on
+the mind by the actual impression of the moment.
+
+_Involuntary Mental Preadjustment._
+
+
+If we glance back at the examples of capricious selection just noticed,
+we shall see that they are really limited not only by the character of
+the impression of the time, but also by the mental habits of the
+spectator. That is to say, we find that his fancy runs in certain
+definite directions, and takes certain habitual forms. It has already
+been observed that the percipient mind has very different attitudes with
+respect to various kinds of impression. Towards some it holds itself at
+a distance, while towards others it at once bears itself familiarly; the
+former are such as answer to its previous habit and bent of imagination,
+the latter such as do not so answer.
+
+This bent of the interpretative imagination assumes, as we have already
+seen, two forms, that of a comparatively permanent disposition, and that
+of a temporary state of expectation or mental preparedness. Illusion may
+arise in connection with either of these forms. Let us illustrate both
+varieties, beginning with those which are due to a lasting mental
+disposition.
+
+It is impossible here to specify all the causes of illusion residing in
+organized tendencies of the mind. The whole past mental life, with its
+particular shade of experience, its ruling emotions, and its habitual
+direction of fancy, serves to give a particular colour to new
+impressions, and so to favour illusion. There is a "personal equation"
+in perception as in belief--an amount of erroneous deviation from the
+common average view of external things, which is the outcome of
+individual temperament and habits of mind. Thus, a naturally timid man
+will be in general disposed to see ugly and fearful objects where a
+perfectly unbiased mind perceives nothing of the kind; and the forms
+which these objects of dread will assume are determined by the character
+of his past experience, and by the customary direction of his
+imagination.
+
+In perfectly healthy states of mind this influence of temperament and
+mental habit on the perception of external objects is, of course, very
+limited; it shows itself more distinctly, as we shall see, in modifying
+the estimate of things in relation to the aesthetic and other feelings.
+This applies to the mythical poetical way of looking at nature--a part
+of our subject to which we shall have to return later on.
+
+Passing now from the effect of such permanent dispositions, let us look
+at the more striking results of temporary expectancy of mind.
+
+When touching on the influence of such a temporary mental attitude in
+the process of correct perception, I remarked that this readiness of
+mind might assume an indefinite or a definite form. We will examine the
+effect of each kind in the production of illusion.
+
+
+_Action of Sub-Expectation._
+
+First of all, then, our minds may at the particular moment be disposed
+to entertain any one of a vaguely circumscribed group of images. Thus,
+to return to the example already referred to, when in Italy, we are in a
+state of readiness to frame any of the images that we have learnt to
+associate with this country. We may not be distinctly anticipating any
+one kind of object, but are nevertheless in a condition of
+_sub-expectation_ with reference to a large number of objects.
+Accordingly, when an impression occurs which answers only very roughly
+to one of the associated images, there is a tendency to superimpose the
+image on the impression. In this way illusion arises. Thus, a man, when
+strolling in a cathedral, will be apt to take any kind of faint hollow
+sound for the soft tones of an organ.
+
+The disposition to anticipate fact and reality in this way will be all
+the stronger if, as usually happens, the mental images thus lying ready
+for use have an emotional colouring. Emotion is the great disturber of
+all intellectual operations. It effects marvellous things, as we shall
+presently see, in the region of illusory belief, and its influence is
+very marked in the seemingly cooler region of external perception. The
+effect of any emotional excitement appears to be to give a preternatural
+vividness and persistence to the ideas answering to it, that is to say,
+the ideas which are its excitants, or which are otherwise associated
+with it. Owing to this circumstance, when the mind is under the
+temporary sway of any feeling, as, for example, fear, there will be a
+special readiness to interpret objects by help of images congruent with
+the emotion. Thus, a man under the control of fear will be ready to see
+any kind of fear-inspiring object whenever there is any resemblance to
+such in the things actually present to his vision. The state of awe
+which the surrounding circumstances of a spiritualist _seance_ inspires
+produces a general readiness of mind to perceive what is strange,
+mysterious, and apparently miraculous.
+
+It is worth noting, perhaps, that those delightful half-illusions which
+imitative art seeks to produce are greatly favoured by such a temporary
+attitude of the interpreting imagination. In the theatre, for example,
+we are prepared for realizing the semblance of life that is to be
+unfolded before us. We come knowing that what is to be performed aims at
+representing a real action or actual series of events. We not improbably
+work ourselves into a slightly excited state in anticipation of such a
+representation. More than this, as the play progresses, the realization
+of what has gone before produces a strong disposition to believe in the
+reality of what is to follow. And this effect is proportionate to the
+degree of coherence and continuity in the action. In this way, there is
+a cumulative effect on the mind. If the action is good, the illusion, as
+every play-goer knows, is most complete towards the end.
+
+Were it not for all this mental preparation, the illusory character of
+the performance would be too patent to view, and our enjoyment would
+suffer. A man is often aware of this when coming into a theatre during
+the progress of a piece before his mind accommodates itself to the
+meaning of the play. And the same thing is recognizable in the fact that
+the frequenter of the theatre has his susceptibility to histrionic
+delusion increased by acquiring a habit of looking out for the meaning
+of the performance. Persons who first see a play, unless they be of
+exceptional imagination and have thought much about the theatre--as
+Charlotte Bronte, for instance--hardly feel the illusion at all. At
+least, this is true of the opera, where the departure from reality is
+so striking that the impression can hardly fail to be a ludicrous one,
+till the habit of taking the performance for what it is intended to be
+is fully formed.[51]
+
+A similar effect of intellectual preadjustment is observable in the
+fainter degrees of illusion produced by pictorial art. Here the
+undeceiving circumstances, the flat surface, the surroundings, and so
+on, would sometimes be quite sufficient to prevent the least degree of
+illusion, were it not that the spectator comes prepared to see a
+representation of some real object. This is our state of mind when we
+enter a picture gallery or approach what we recognize as a picture on
+the wall of a room. A savage would not "realize" a slight sketch as soon
+as one accustomed to pictorial representation, and ready to perform the
+required interpretative act.[52]
+
+So much as to the effect of an indefinite state of sub-expectation in
+misleading our perceptions. Let us now glance at the results of definite
+preimagination, including what are generally known as expectations.
+
+_Effects of Vivid Expectation._
+
+
+Such expectations may grow out of some present objective facts, which
+serve as signs of the expected event; or they may arise by way of verbal
+suggestion; or, finally, they may be due to internal spontaneous
+imagination.
+
+In the first place, then, the expectations may grow out of previous
+perceptions, while, nevertheless, the direction of the expectation may
+be a wrong one. Here the interpreting imagination is, in a large sense,
+under the control of external suggestion, though, with respect to the
+particular impression that is misconstrued, it may be regarded as acting
+independently and spontaneously.
+
+Illustrations of this effect in producing illusion will easily occur to
+the reader. If I happen to have heard that a particular person has been
+a soldier or clergyman, I tend to see the marks of the class in this
+person, and sometimes find that this process of recognition is
+altogether illusory. Again, let us suppose that a person is expecting a
+friend by a particular train. A passenger steps out of the train bearing
+a superficial resemblance to his friend; in consequence of which he
+falls into the error of false identification.
+
+The delusions of the conjuror depend on a similar principle. The
+performer tells his audience that he is about to do a certain thing, for
+example, take a number of animals out of a small box which is incapable
+of holding them. The hearers, intent on what has been said, vividly
+represent to themselves the action described. And in this way their
+attention becomes bribed, so to speak, beforehand, and fails to notice
+the inconspicuous movements which would at once clear up the mystery.
+Similarly with respect to the illusions which overtake people at
+spiritualist _seances_. The intensity of the expectation of a particular
+kind of object excludes calm attention to what really happens, and the
+slightest impressions which answer to signs of the object anticipated
+are instantly seized by the mind and worked up into illusory
+perceptions.
+
+It is to be noted that even when the impression cannot be made to tally
+exactly with the expectation, the force of the latter often effects a
+grotesque confusion of the perception. If, for example, a man goes into
+a familiar room in the dark in order to fetch something, and for a
+moment forgets the particular door by which he has entered, his definite
+expectation of finding things in a certain order may blend with the
+order of impressions experienced, producing for the moment a most
+comical illusion as to the actual state of things.
+
+When the degree of expectation is unusually great, it may suffice to
+produce something like the counterfeit of a real sensation. This happens
+when the present circumstances are powerfully suggestive of an immediate
+event. The effect is all the more powerful, moreover, in those cases
+where the object or event expected is interesting or exciting, since
+here the mental image gains in vividness through the emotional
+excitement attending it. Thus, if I am watching a train off and know
+from all the signs that it is just about to start, I easily delude
+myself into the conviction that it has begun to start, when it is
+really still.[53] An intense degree of expectation may, in such cases,
+produce something indistinguishable from an actual sensation. This
+effect is seen in such common experiences as that the sight of food
+makes the mouth of a hungry man water; that the appearance of a surgical
+instrument produces a nascent sensation of pain; and that a threatening
+movement, giving a vivid anticipation of tickling, begets a feeling
+which closely approximates to the result of actual tickling.
+
+One or two very striking instances of such imagined sensations are given
+by Dr. Carpenter.[54] Here is one. An officer who superintended the
+exhuming of a coffin rendered necessary through a suspicion of crime,
+declared that he already experienced the odour of decomposition, though
+it was afterwards found that the coffin was empty.[55]
+
+It is, of course, often difficult to say, in such cases as these, how
+far elements of actual sensation co-operate in the production of the
+illusions. Thus, in the case just mentioned, the odour of the earth may
+have been the starting-point in the illusion. In many cases, however, an
+imaginative mind appears to be capable of transforming a vivid
+expectation into a nascent stage of sensation. Thus, a mother thinking
+of her sick child in an adjoining room, and keenly on the alert for its
+voice, will now and again fancy she really hears it when others hear
+nothing at all.
+
+
+_Transition to Hallucination._
+
+It is plain that in these cases illusion approaches to hallucination.
+Imagination, instead of waiting on sensation, usurps its place and
+imitates its appearance. Such a "subjective" sensation produced by a
+powerful expectation might, perhaps, by a stretch of language, be
+regarded as an illusion, in the narrow sense, in so far as it depends on
+the suggestive force of a complete set of external circumstances; on the
+other hand, it is clearly an hallucination in so far as it is the
+production of the semblance of an external impression without any
+external agency corresponding to this.
+
+In the class of illusory expectations just considered the immediately
+present environment still plays a part, though a much less direct part
+than that observable in the first large group of illusions. We will now
+pass to a second mode of illusory expectation, where imagination is
+still more detached from the present surroundings.
+
+A common instance of this kind of expectation is the so-called
+"intuition," or presentiment; that something is going to happen, which
+expectation has no basis in fact. It does not matter whether the
+expectation has arisen by way of another's words or by way of personal
+inclinations. A strong wish for a thing will, in an exalted state of
+mind, beget a vivid anticipation of it. This subject will be touched on
+again under the Illusions of Belief. Here I am concerned to point out
+that such presentiments are fertile sources of sense-illusion. The
+history of Church miracles, visions, and the like amply illustrates the
+effect of a vivid anticipation in falsifying the perceptions of external
+things.
+
+In persons of a lively imagination any recent occupation of the mind
+with a certain kind of mental image may suffice to beget something
+equivalent to a powerful mode of expectation. For example, we are told
+by Dr. Tuke that on one occasion a lady, whose imagination had been
+dwelling on the subject of drinking fountains, "thought she saw in a
+road a newly erected fountain, and even distinguished an inscription
+upon it, namely, 'If any man thirst, let him come unto Me, and drink.'
+She afterwards found that what she had actually seen was only a few
+scattered stones."[56] In many cases there seems to be a temporary
+preternatural activity of the imagination in certain directions, of
+which no very obvious explanation is discoverable. Thus, we sometimes
+find our minds dwelling on some absent friend, without being able to
+give any reason for this mental preoccupation. And in this way arise
+strong temporary leanings to illusory perception. It may be said,
+indeed, that all unwonted activity of the imagination, however it
+arises, has as its immediate result a temporary mode of expectation,
+definite or indefinite, which easily confuses our perceptions of
+external things.
+
+In proportion as this pre-existing imaginative impulse becomes more
+powerful, the amount of actual impression necessary to transform the
+mental image into an illusory perception becomes less; and, what is more
+important, this transformation of the internal image involves a larger
+and larger displacement of the actual impression of the moment. A man
+whose mind is at the time strongly possessed by one kind of image, will
+tend to project this outwards with hardly any regard to the actual
+external circumstances.
+
+This state of things is most completely illustrated in many of the
+grosser illusions of the insane. Thus, when a patient takes any small
+objects, as pebbles, for gold and silver, under the influence of the
+dominant idea of being a millionaire, it is obvious that external
+suggestion has very little to do with the self-deception. The confusions
+into which the patient often falls with respect to the persons before
+him show the same state of mind; for in many cases there is no
+discoverable individual resemblance between the person actually present
+and the person for whom he is taken.
+
+It is evident that when illusion reaches this stage, it is scarcely
+distinguishable from what is specially known as hallucination. As I have
+remarked in setting out, illusion and hallucination shade one into the
+other much too gradually for us to draw any sharp line of demarcation
+between them. And here we see that hallucination differs from illusion
+only in the proportion in which the causes are present. When the
+internal imaginative impulse reaches a certain strength, it becomes
+self-sufficient, or independent of any external impression.
+
+This intimate relation between the extreme form of active illusion and
+hallucination may be seen, too, by examining the physical conditions of
+each. As I have already remarked, active illusion has for its
+physiological basis a state of sub-excitation, or an exceptional
+condition of irritability in the structures engaged in the act of
+interpretative imagination. The greater the degree of this irritability,
+the less will be the force of external stimulation needed to produce the
+effect of excitation, and the more energetic will be the degree of this
+excitation. Moreover, it is plain that this increase in the strength of
+the excitation will involve an extension of the area of excitation till,
+by-and-by, the peripheral regions of the nervous system may be involved
+just as in the case of external stimulation. This accounts for the
+gradual displacement of the impression of the moment by the mental
+image. It follows that when the irritability reaches a certain degree,
+the amount of external stimulus needed may become a vanishing quantity,
+or the state of sub-excitation may of itself develop into one of full
+activity.
+
+
+_Hallucinations._
+
+I do not propose to go very fully into the description and explanation
+of hallucinations here, since they fall to a large extent under the
+category of distinctly pathological phenomena. Yet our study of
+illusions would not be complete without a glance at this part of the
+subject.
+
+Hallucination, by which I mean the projection of a mental image outwards
+when there is no external agency answering to it, assumes one of two
+fairly distinct forms: it may present itself either as a semblance of an
+external impression with the minimum amount of interpretation, or as a
+counterfeit of a completely developed percept. Thus, a visual
+hallucination may assume the aspect of a sensation of light or colour
+which we vaguely refer to a certain region of the external world, or of
+a vision of some recognizable object. All of us frequently have
+incomplete visual and auditory hallucinations of the first order,
+whereas the complete hallucinations of the second order are
+comparatively rare. The first I shall call rudimentary, the second
+developed, hallucinations.
+
+Rudimentary hallucinations may have either a peripheral or a central
+origin. They may first of all have their starting-point in those
+subjective sensations which, as we have seen, are connected with certain
+processes set up in the peripheral regions of the nervous system. Or,
+secondly, they may originate in a certain preternatural activity of the
+sensory centres, or "sensorium," in what has been called by German
+physiologists an automatic excitation of the central structures, which
+activity may probably diffuse itself downwards to the peripheral regions
+of the nerves. Baillarger would call hallucinations of the former class
+"psycho-sensorial," those of the latter class purely "psychical,"
+hallucinations.[57]
+
+It is often a matter of great difficulty to determine which part of the
+nervous system is originally concerned in these rudimentary
+hallucinations. It is probable that in normal life they are most
+frequently due to peripheral disturbance. And it seems reasonable to
+suppose that where the hallucination remains in this initial stage of a
+very incompletely interpreted visual or auditory impression, whether in
+normal or abnormal life, its real physiological source is the periphery.
+For the automatic excitation of the centres would pretty certainly issue
+in the semblance of some definite, familiar variety of sense-impression
+which, moreover, as a part of a complex state known as a percept, would
+instantly present itself as a completely formed quasi-percept. In truth,
+we may pretty safely argue that if it is the centre which is directly
+thrown into a state of activity, it will be thrown into the usual
+complex, that is to say, _perceptional_, mode of activity.
+
+Let us now turn to hallucinations properly so called, that is to say,
+completely developed quasi-percepts. These commonly assume the form of
+visual or auditory hallucinations. Like the incomplete hallucinations,
+they may have their starting-point either in some disturbance in the
+peripheral regions of the nervous system or in the automatic activity of
+the central structures: or, to use the language of Baillarger, we may
+say that they are either "psycho-sensorial" or purely "psychical." A
+subjective visual sensation, arising from certain conditions in the
+retina and connected portions of the optic nerve, may by chance resemble
+a familiar impression, and so be at once interpreted as an effect of a
+particular external object. More frequently, however, the automatic
+activity of the centres must be regarded, either in part or altogether,
+as the physiological cause of the phenomenon. This is clearly the case
+when, on the subjective side, the hallucination answers to a preceding
+energetic activity of the imagination, as in the case of the visionary
+and the monomaniac. Sometimes, however, as we have seen, the
+hallucinatory percept answers to previous prolonged acts of perception,
+leaving a kind of reverberation in the structures concerned; and in this
+case it is obviously impossible to say whether the peripheral or central
+regions (if either) have most to do with the hallucination.[58]
+
+The classifications of the causes of hallucination to be met with in the
+works of pathologists, bear out the distinction just drawn. Griesinger
+tells us (_op. cit._, pp. 94, 95) that the general causes of
+hallucination are: (1) Local disease of the organ of sense; (2) a state
+of deep exhaustion either of mind or of body; (3) morbid emotional
+states, such as fear; (4) outward calm and stillness between sleeping
+and waking; and (5) the action of certain poisons, as haschisch, opium,
+belladonna. The first cause points pretty distinctly to a peripheral
+origin, whereas the others appear to refer mainly, if not exclusively,
+to central derangements. Excessive fatigue appears to predispose the
+central structures to an abnormal kind of activity, and the same effect
+may be brought about by emotional agitation and by the action of
+poisons. The fourth case mentioned here, absence of external
+stimulation, would naturally raise the nervous structures to an
+exceptional pitch of excitability. Such a condition would, moreover,
+prove favourable to hallucination by blurring the distinction between
+mental image and actual impression.
+
+
+_Hallucinations of Normal Life._
+
+In normal life, perfect hallucinations, in the strict sense as distinct
+from illusions, are comparatively rare. Fully developed persistent
+hallucinations, as those of Nicolai, the Berlin bookseller, and of Mrs.
+A----, the lady cited by Sir D. Brewster, in his _Letters on Natural
+Magic_, point to the presence of incipient nervous disorder. In healthy
+life, on the other hand, while everybody is familiar with subjective
+sensations such as flying spots, phosphenes, ringing in the ears, few
+fall into the error of seeing or hearing distinct recognizable objects
+in the absence of all external impressions. In the lives of eminent men
+we read of such phenomena as very occasional events. Malebranche, for
+example, is said to have heard the voice of God calling him. Descartes
+says that, after a long confinement, he was followed by an invisible
+person, calling him to pursue his search for truth. Dr. Johnson narrates
+that he once heard his absent mother calling him. Byron tells us that he
+was sometimes visited by spectres. Goethe records that he once saw an
+exact counterpart of himself coming towards him. Sir Walter Scott is
+said to have seen a phantom of the dead Byron. It is possible that all
+of us are liable to momentary hallucinations at times of exceptional
+nervous exhaustion, though they are too fugitive to excite our
+attention.
+
+When not brought on by exhaustion or artificial means, the
+hallucinations of the sane have their origin in a preternatural power of
+imagination. It is well known that this power can be greatly improved by
+attention and cultivation. Goethe used to exercise himself in watching
+for ocular spectra, and could at will transform these subjective
+sensations into definite forms, such as flowers; and Johannes Mueller
+found he had the same power.[59] Stories are told of portrait painters
+who could summon visual images of their sitters with a vividness equal
+to that of reality, and serving all the purposes of their art. Mr.
+Galton's interesting inquiries into the power of "visualizing" would
+appear to prove that many people can at will sport on the confines of
+the phantom world of hallucination. There is good reason to think that
+imaginative children tend to confuse mental images and percepts.[60]
+
+_The Hallucinations of Insanity._
+
+
+The hallucinations of the insane are but a fuller manifestation of
+forces that we see at work in normal life. Their characteristic is that
+they simulate the form of distinctly present objects, the existence of
+which is not instantly contradicted by the actual surroundings of the
+moment.[61] The hallucinations have their origin partly in subjective
+sensations, which are probably connected with peripheral disturbances,
+partly and principally in central derangements.[62] These include
+profound emotional changes, which affect the ruling mental tone, and
+exert a powerful influence on the course of the mental images. The
+hallucinations of insanity are due to a projection of mental images
+which have, owing to certain circumstances, gained a preternatural
+persistence and vividness. Sometimes it is the images that have been
+dwelt on with passionate longing before the disease, sometimes those
+which have grown most habitual through the mode of daily
+occupation,[63] and sometimes those connected with some incident at or
+near the time of the commencement of the disease.
+
+In mental disease, auditory hallucinations play a part no less
+conspicuous than visual.[64] Patients frequently complain of having
+their thoughts spoken to them, and it is not uncommon for them to
+imagine that they are addressed by a number of voices at the same
+time.[65]
+
+These auditory hallucinations offer a good opportunity for studying the
+gradual growth of centrally originating hallucinations. In the early
+stages of the disease, the patient partly distinguishes his
+representative from his preservative sounds. Thus, he talks of sermons
+being composed to him _in his head_. He calls these "internal voices,"
+or "voices of the soul." It is only when the disease gains ground and
+the central irritability increases that these audible thoughts become
+distinctly projected as external sounds into more or less definite
+regions of the environment. And it is exceedingly curious to notice the
+different directions which patients give to these sounds, referring them
+now to a quarter above the head, now to a region below the floor, and so
+on.[66]
+
+
+_Range of Sense-Illusions._
+
+And now let us glance back to see the path we have traversed. We set out
+with an account of perfectly normal perception, and found, even here, in
+the projection of our sensations of colour, sound, etc., into the
+environment or to the extremities of the organism, something which, from
+the point of view of physical science, easily wears the appearance of an
+ingredient of illusion.
+
+Waiving this, however, and taking the word illusion as commonly
+understood, we find that it begins when the element of imagination no
+longer answers to a present reality or external fact in any sense of
+this expression. In its lowest stages illusion closely counterfeits
+correct perception in the balance of the direct factor, sensation, and
+the indirect factor, mental reproduction or imagination. The degree of
+illusion increases in proportion as the imaginative element gains in
+force relatively to the present impression; till, in the wild illusions
+of the insane, the amount of actual impression becomes evanescent. When
+this point is reached, the act of imagination shows itself as a purely
+creative process, or an hallucination.
+
+While we may thus trace the progress of illusion towards hallucination
+by means of the gradual increase in force and extent of the imaginative,
+or indirect, as opposed to the sensuous, or direct, element in
+perception, we have found a second starting-point for this movement in
+the mechanism of sensation, involving, as it does, the occasional
+production of "subjective sensations." Such sensations constitute a
+border-land between the regions of illusion in the narrow sense, and
+hallucination. In their simplest and least developed form they may be
+regarded, at least in the case of hearing and sight, as partly
+hallucinatory; and they serve as a natural basis for the construction of
+complete hallucinations, or hallucinatory percepts.
+
+In these different ways, then, the slight, scarcely noticeable illusions
+of normal life lead up to the most startling hallucinations of abnormal
+life. From the two poles of the higher centres of attention and
+imagination on the one side, and the lower regions of nervous action
+involved in sensation on the other side, issue forces which may, under
+certain circumstances, develop into full hallucinatory percepts. Thus
+closely is healthy attached to morbid mental life. There seems to be no
+sudden break between our most sober every-day recognitions of familiar
+objects and the wildest hallucinations of the demented. As we pass from
+the former to the latter, we find that there is never any abrupt
+transition, never any addition of perfectly new elements, but only that
+the old elements go on combining in ever new proportions.
+
+The connection between the illusory side of our life and insanity may be
+seen in another way. All illusion has as its negative condition an
+interruption of the higher intellectual processes, the due control of
+our mental representations by reflection and reason. In the case of
+passive illusions, the error arises from our inability to subordinate
+the suggestion made by some feature of the present impression to the
+result of a fuller inspection of the object before us, or of a wider
+reflection on the past. In other words, our minds are dominated by the
+partial and the particular, to the exclusion of the total or the
+general. In active illusions, again, the powers of judgment and
+reflection, including those of calm perception itself, temporarily
+vacate their throne in favour of imagination. And this same suspension
+of the higher intellectual functions, the stupefaction of judgment and
+reflection made more complete and permanent, is just what characterizes
+insanity.
+
+We may, perhaps, express this point of connection between the illusions
+of normal life and insanity by help of a physiological hypothesis. If
+the nervous system has been slowly built up, during the course of human
+history, into its present complex form, it follows that those nervous
+structures and connections which have to do with the higher intellectual
+processes, or which represent the larger and more general relations of
+our experience, have been most recently evolved. Consequently, they
+would be the least deeply organized, and so the least stable; that is
+to say, the most liable to be thrown _hors de combat_. This is what
+happens temporarily in the case of the sane, when the mind is held fast
+by an illusion. And, in states of insanity, we see the process of
+nervous dissolution beginning with these same nervous structures, and so
+taking the reverse order of the process of evolution.[67] And thus, we
+may say that throughout the mental life of the most sane of us, these
+higher and more delicately balanced structures are constantly in danger
+of being reduced to that state of inefficiency, which in its full
+manifestation is mental disease.
+
+Does this way of putting the subject seem alarming? Is it an appalling
+thought that our normal mental life is thus intimately related to
+insanity, and graduates away into it by such fine transitions? A
+moment's reflection will show that the case is not so bad as it seems.
+It is well to remind ourselves that the brain is a delicately adjusted
+organ, which very easily gets disturbed, and that the best of us are
+liable to become the victims of absurd illusion if we habitually allow
+our imaginations to be overheated, whether by furious passion or by
+excessive indulgence in the pleasures of day-dreaming, or in the
+intoxicating mysteries of spiritualist _seances_. But if we take care to
+keep our heads cool and avoid unhealthy degrees of mental excitement, we
+need not be very anxious on the ground of our liability to this kind of
+error. As I have tried to show, our most frequent illusions are
+necessarily connected with something exceptional, either in the
+organism or in the environment. That is to say, it is of the nature of
+illusion in healthy conditions of body and mind to be something very
+occasional and relatively unimportant. Our perceptions may be regarded
+as the reaction of the mind on the impressions borne in from the
+external world, or as a process of adjustment of internal mental
+relations to external physical relations. If this process is, in the
+main, a right one, we need not greatly trouble, because it is not
+invariably so. We should accept the occasional failure of the
+intellectual mechanism as an inseparable accompaniment of its general
+efficiency.
+
+To this it must be added that many of the illusions described above can
+hardly be called cases of non-adaptation at all, since they have no
+relation to the practical needs of life, and consequently are, in a
+general way, unattended to. In other cases, again, namely, where the
+precise nature of a present sensation, being practically an unimportant
+matter, is usually unattended to, as in the instantaneous recognition of
+objects by the eye under changes of illumination, etc., the illusion is
+rather a part of the process of adaptation, since it is much more
+important to recognize the permanent object signified by the sensation
+than the precise nature of the present sensational "sign" itself.
+
+Finally, it should never be forgotten that in normal states of mind
+there is always the possibility of rectifying an illusion. What
+distinguishes abnormal from normal mental life is the persistent
+occupation of the mind by certain ideas, so that there is no room for
+the salutary corrective effect of reflection on the actual impression
+of the moment, by which we are wont to "orientate," or take our bearings
+as to the position of things about us. In sleep, and in certain
+artificially produced states, much the same thing presents itself.
+Images become realities just because they are not instantly recognized
+as such by a reference to the actual surroundings of the moment. But in
+normal waking life this power of correction remains with us. We may not
+exercise it, it is true, and thus the illusion will tend to become more
+or less persistent and recurring; for the same law applies to true and
+to false perception: repetition makes the process easier. But if we only
+choose to exert ourselves, we can always keep our illusions in a nascent
+or imperfectly developed stage. This applies not only to those
+half-illusions into which we voluntarily fall, but also to the more
+irresistible passive illusions, and those arising from an over-excited
+imagination. Even persons subject to hallucinations, like Nicolai of
+Berlin, learn to recognize the unreal character of these phantasms. On
+this point the following bit of autobiography from the pen of Coleridge
+throws an interesting light. "A lady (he writes) once asked me if I
+believed in ghosts and apparitions. I answered with truth and
+simplicity, No, madam, I have seen far too many myself."[68] However
+irresistible our sense-illusions may be, so long as we are under the
+sway of particular impressions or mental images, we can, when resolved
+to do so, undeceive ourselves by carefully attending to the actual
+state of things about us. And in many cases, when once the correction is
+made, the illusion seems an impossibility. By no effort of imagination
+are we able to throw ourselves back into the illusory mental condition.
+So long as this power of dispelling the illusion remains with us, we
+need not be alarmed at the number and variety of the momentary
+misapprehensions to which we are liable.
+
+
+
+
+CHAPTER VII.
+
+DREAMS.
+
+
+The phenomena of dreams may well seem at first sight to form a world of
+their own, having no discoverable links of connection with the other
+facts of human experience. First of all, there is the mystery of sleep,
+which quietly shuts all the avenues of sense and so isolates the mind
+from contact with the world outside. To gaze at the motionless face of a
+sleeper temporarily rapt from the life of sight, sound, and
+movement--which, being common to all, binds us together in mutual
+recognition and social action--has always something awe-inspiring. This
+external inaction, this torpor of sense and muscle, how unlike to the
+familiar waking life, with its quick responsiveness and its overflowing
+energy! And then, if we look at dreams from the inside, we seem to find
+but the reverse face of the mystery. How inexpressibly strange does the
+late night-dream seem to a person on waking! He feels he has been seeing
+and hearing things no less real than those of waking life; but things
+which belong to an unfamiliar world, an order of sights and a sequence
+of events quite unlike those of waking experience; and he asks himself
+in his perplexity where that once-visited region really lies, or by what
+magic power it was suddenly and for a moment created for his vision. In
+truth, the very name of dream suggests something remote and mysterious,
+and when we want to characterize some impression or scene which by its
+passing strangeness filled us with wonder, we naturally call it
+dream-like.
+
+
+_Theories of Dreams._
+
+The earliest theories respecting dreams illustrate very clearly this
+perception of the remoteness of dream-life from waking experience. By
+the simple mind of primitive man this dream-world is regarded as similar
+in its nature or structure to our common world, only lying remote from
+this. The savage conceives that when he falls asleep, his second self
+leaves his familiar body and journeys forth to unfamiliar regions, where
+it meets the departed second selves of his dead ancestors, and so on.
+From this point of view, the experience of the night, though equal in
+reality to that of the day, is passed in a wholly disconnected
+region.[69]
+
+A second and more thoughtful view of dreams, marking a higher grade of
+intellectual culture, is that these visions of the night are symbolic
+pictures unfolded to the inner eye of the soul by some supernatural
+being. The dream-experience is now, in a sense, less real than it was
+before, since the phantasms that wear the guise of objective realities
+are simply images spread out to the spirit's gaze, or the direct
+utterance of a divine message. Still, this mysterious contact of the
+mind with the supernatural is regarded as a fact, and so the dream
+assumes the appearance of a higher order of experience. Its one point of
+attachment to the experience of waking life lies in its symbolic
+function; for the common form which this supernatural view assumes is
+that the dream is a dim prevision of coming events. Artemidorus, the
+great authority on dream interpretation (_oneirocritics_) for the
+ancient world, actually defines a dream as "a motion or fiction of the
+soul in a diverse form signifying either good or evil to come;" and even
+a logician like Porphyry ascribes dreams to the influence of a good
+demon, who thereby warns us of the evils which another and bad demon is
+preparing for us. The same mode of viewing dreams is quite common
+to-day, and many who pride themselves on a certain intellectual culture,
+and who imagine themselves to be free from the weakness of superstition,
+are apt to talk of dreams as of something mysterious, if not distinctly
+ominous. Nor is it surprising that phenomena which at first sight look
+so wild and lawless, should still pass for miraculous interruptions of
+the natural order of events.[70]
+
+Yet, in spite of this obvious and impressive element of the mysterious
+in dream-life, the scientific impulse to illuminate the less known by
+the better known has long since begun to play on this obscure subject.
+Even in the ancient world a writer might here and there be found, like
+Democritus or Aristotle, who was bold enough to put forward a natural
+and physical explanation of dreams. But it has been the work of modern
+science to provide something like an approximate solution of the
+problem. The careful study of mental life in its intimate union with
+bodily operations, and the comparison of dream-combinations with other
+products of the imagination, normal as well as morbid, have gradually
+helped to dissolve a good part of the mystery which once hung like an
+opaque mist about the subject. In this way, our dream-operations have
+been found to have a much closer connection with our waking experiences
+than could be supposed on a superficial view. The materials of our
+dreams are seen, when closely examined, to be drawn from our waking
+experience. Our waking consciousness acts in numberless ways on our
+dreams, and these again in unsuspected ways influence our waking mental
+life.[71] Not only so, it is found that the quaint chaotic play of
+images in dreams illustrates mental processes and laws which are
+distinctly observable in waking thought. Thus, for example, the apparent
+objective reality of these visions has been accounted for, without the
+need of resorting to any supernatural agency, in the light of a vast
+assemblage of facts gathered from the by-ways, so to speak, of waking
+mental life. I need hardly add that I refer to the illusions of sense
+dealt with in the foregoing chapters.
+
+Dreams are to a large extent the semblance of external perceptions.
+Other psychical phenomena, as self-reflection, emotional activity, and
+so on, appear in dream-life, but they do so in close connection with
+these quasi-perceptions. The name "vision," given by old writers to
+dreams, sufficiently points out this close affinity of the mental
+phenomena to sense-perception; and so far as science is concerned, they
+must be regarded as a peculiar variety of sense-illusion. Hence the
+appropriateness of studying them in close connection with the illusions
+of perception of the waking state. Though marked off by the presence of
+very exceptional physiological conditions, they are largely intelligible
+by help of these physiological and psychological principles which we
+have just been considering.
+
+
+_The State of Sleep._
+
+The physiological explanation of dreams must, it is plain, set out with
+an account of the condition of the organism known as sleep. While there
+is here much that is uncertain, there are some things which are fairly
+well known. Recent physiological observation has gone to prove that
+during sleep all the activities of the organism are appreciably lowered.
+Thus, for example, according to Testa, the pulse falls by about
+one-fifth. This lowering of the organic functions appears, under
+ordinary circumstances, to increase towards midnight, after which there
+is a gradual rising.
+
+The nervous system shares in this general depression of the vital
+activities. The circulation being slower, the process of reparation and
+nutrition of the nerves is retarded, and so their degree of excitability
+diminished. This is clearly seen in the condition of the peripheral
+regions of the nervous system, including the sense-organs, which appear
+to be but very slightly acted on by their customary stimuli.
+
+The nervous centres must participate in this lethargy of the system. In
+other words, the activity of the central substance is lowered, and the
+result of this is plainly seen in what is usually thought of as the
+characteristic feature of sleep, namely, a transition from vigorous
+mental activity or intense and clear consciousness, to comparative
+inactivity or faint and obscure consciousness. The cause of this
+condition of the centres is supposed to be the same as that of the
+torpidity of all the other organs in sleep, namely, the retardation of
+the circulation. But, though there is no doubt as to this, the question
+of the proximate physiological conditions of sleep is still far from
+being settled. Whether during sleep the blood-vessels of the brain are
+fuller or less full than during waking, is still a moot point. Also the
+qualitative condition of the blood in the cerebral vessels is still a
+matter of discussion.[72]
+
+Since the effect of sleep is to lower central activity, the question
+naturally occurs whether the nervous centres are ever rendered inactive
+to such an extent as to interrupt the continuity of our conscious life.
+This question has been discussed from the point of view of the
+metaphysician, of the psychologist, and of the physiologist, and in no
+case is perfect unanimity to be found. The metaphysical question,
+whether the soul as a spiritual substance is capable of being wholly
+inactive, or whether it is not in what seem the moments of profoundest
+unconsciousness partially awake--the question so warmly discussed by the
+Cartesians, Leibnitz, etc.--need not detain us here.
+
+Of more interest to us are the psychological and the physiological
+discussions. The former seeks to settle the question by help of
+introspection and memory. On the one side, it is urged against the
+theory of unbroken mental activity, that we remember so little of the
+lowered consciousness of sleep.[73] To this it is replied that our
+forgetfulness of the contents of dream-consciousness, even if this were
+unbroken, would be fully accounted for by the great dissimilarity
+between dreaming and waking mental life. It is urged, moreover, on this
+side that a sudden rousing of a man from sleep always discovers him in
+the act of dreaming, and that this goes to prove the uniform connection
+of dreaming and sleeping. This argument, again, may be met by the
+assertion that our sense of the duration of our dreams is found to be
+grossly erroneous; that, owing to the rapid succession of the images,
+the _realization_ of which would involve a long duration, we enormously
+exaggerate the length of dreams in retrospection.[74] From this it is
+argued that the dream which is recalled on our being suddenly awakened
+may have had its whole course during the transition state of waking.
+
+Again, the fact that a man may resolve, on going to sleep, to wake at a
+certain hour, has often been cited in proof of the persistence of a
+degree of mental activity even in perfectly sound sleep. The force of
+this consideration, however, has been explained away by saying that the
+anticipation of rising at an unusual hour necessarily produces a slight
+amount of mental disquietude, which is quite sufficient to prevent sound
+sleep, and therefore to expose the sleeper to the rousing action of
+faint external stimuli.
+
+While the purely psychological method is thus wholly inadequate to solve
+the question, physiological reasoning appears also to be not perfectly
+conclusive. Many physiologists, not unnaturally desirous of upsetting
+what they regard as a gratuitous metaphysical hypothesis, have
+pronounced in favour of an absolutely dreamless or unconscious sleep.
+From the physiological point of view, there is no mystery in a totally
+suspended mental activity. On the other hand, there is much to be said
+on the opposite side, and perhaps it may be contended that the purely
+physiological evidence rather points to the conclusion that central
+activity, however diminished during sleep, always retains a minimum
+degree of intensity. At least, one would be disposed to argue in this
+way from the analogy of the condition of the other functions of the
+organism during sleep. Possibly this modicum of positive evidence may
+more than outweigh any slight presumption against the doctrine of
+unbroken mental activity drawn from the negative circumstance that we
+remember so little of our dream-life.[75]
+
+Such being the state of physiological knowledge respecting the
+immediate conditions of sleep, we cannot look for any certain
+information on the nature of that residual mode of cerebral activity
+which manifests itself subjectively in dreams. It is evident, indeed,
+that this question can only be fully answered when the condition of the
+brain as a whole during sleep is understood. Meanwhile we must be
+content with vague hypotheses.
+
+It may be said, for one thing, that during sleep the nervous substance
+as a whole is less irritable than during waking hours. That is to say, a
+greater amount of stimulus is needed to produce any conscious
+result.[76] This appears plainly enough in the case of the peripheral
+sense-organs. Although these are not, as it is often supposed, wholly
+inactive during sleep, they certainly require a more potent external
+stimulus to rouse them to action. And what applies to the peripheral
+regions applies to the centres. In truth, it is clearly impossible to
+distinguish between the diminished irritability of the peripheral and
+that of the central structures.
+
+At first sight it seems contradictory to the above to say that stimuli
+which have little effect on the centres of consciousness during waking
+life produce an appreciable result in sleep. Nevertheless, it will be
+found that this is the case. Thus organic processes which scarcely make
+themselves known to the mind in a waking state, may be shown to be the
+originators of many of our dreams. This fact can only be explained on
+the physical side by saying that the special cerebral activities
+engaged in an act of attention are greatly liberated during sleep by the
+comparative quiescence of the external senses. These activities, by
+co-operating with the faint results of the stimuli coming from the
+internal organs, serve very materially to increase their effect.
+
+Finally, it is to be observed that, while the centres thus respond with
+diminished energy to peripheral stimuli, external and internal, they
+undergo a direct, or "automatic," mode of excitation, being roused into
+activity independently of an incoming nervous impulse. This automatic
+stimulation has been plausibly referred to the action of the products of
+decomposition accumulating in the cerebral blood-vessels.[77] It is
+possible that there is something in the nature of this stimulation to
+account for the force and vividness of its conscious results, that is to
+say, of dreams.
+
+
+_The Dream State._
+
+Let us now turn to the psychic side of these conditions, that is to say,
+to the general character of the mental states known as dreams. It is
+plain that the closing of the avenues of the external senses, which is
+the accompaniment of sleep, will make an immense difference in the
+mental events of the time. Instead of drawing its knowledge from
+without, noting its bearings in relation to the environment, the mind
+will now be given over to the play of internal imagination. The activity
+of fancy will, it is plain, be unrestricted by collision with external
+fact. The internal mental life will expand in free picturesque
+movement.
+
+To say that in sleep the mind is given over to its own imaginings, is to
+say that the mental life in these circumstances will reflect the
+individual temperament and mental history. For the play of imagination
+at any time follows the lines of our past experience more closely than
+would at first appear, and being coloured with emotion, will reflect the
+predominant emotional impulses of the individual mind. Hence the saying
+of Heraclitus, that, while in waking we all have a common world, in
+sleep we have each a world of our own.
+
+This play of imagination in sleep is furthered by the peculiar attitude
+of attention. When asleep the voluntary guidance of attention ceases;
+its direction is to a large extent determined by the contents of the
+mind at the moment. Instead of holding the images and ideas, and
+combining them according to some rational end, the attention relaxes its
+energies and succumbs to the force of imagination. And thus, in sleep,
+just as in the condition of reverie or day-dreaming, there is an
+abandonment of the fancy to its own wild ways.
+
+It follows that the dream-state will not appear to the mind as one of
+fancy, but as one of actual perception, and of contact with present
+reality. Dreams are clearly illusory, and, unlike the illusions of
+waking life, are complete and persistent.[78] And the reason of this
+ought now to be clear. First of all, the mind during sleep wants what M.
+Taine calls the corrective of a present sensation. When awake under
+ordinary circumstances, any momentary illusion is at once set right by a
+new act of orientation. The superior vividness of the external
+impression cannot leave us in any doubt, when calm and self-possessed,
+whether our mental images answer to present realities or not. On the
+other hand, when asleep, this reference to a fixed objective standard is
+clearly impossible. Secondly, we may fairly argue that the mental images
+of sleep approximate in character to external impressions. This they do
+to some extent in point of intensity, for, in spite of the diminished
+excitability of the centres, the mode of stimulation which occurs in
+sleep may, as I have hinted, involve an energetic cerebral action. And,
+however this be, it is plain that the image will gain a preternatural
+force through the greatly narrowed range of attention. When the mind of
+the sleeper is wholly possessed by an image or group of images, and the
+attention kept tied down to these, there is a maximum reinforcement of
+the images. But this is not all. When the attention is thus held captive
+by the image, it approximates in character to an external impression in
+another way. In our waking state, when our powers of volition are
+intact, the external impression is characterized by its fixity or its
+obdurate resistance to our wishes. On the other hand, the mental image
+is fluent, accommodating, and disappears and reappears according to the
+direction of our volitions. In sleep, through the suspension of the
+higher voluntary power of attention, the mental image seems to lord it
+over our minds just as the actual impression of waking life.
+
+This much may suffice, perhaps, by way of a general description of the
+sleeping and dreaming state. Other points will make themselves known
+after we have studied the contents and structure of dreams in detail.
+
+Dreams are commonly classified (_e.g._ by Wundt) with hallucinations,
+and this rightly, since, as their common appellation of "vision"
+suggests, they are for the most part the semblance of percepts in the
+absence of external impressions. At the same time, recent research goes
+to show that in many dreams something answering to the "external
+impression" in waking perception is the starting-point. Consequently, in
+order to be as accurate as possible, I shall divide dreams into
+illusions (in the narrow sense) and hallucinations.
+
+
+_Dream-Illusions._
+
+By dream-illusions I mean those dreams which set out from some
+peripheral nervous stimulation, internal or external. That the organic
+processes of digestion, respiration, etc., act as stimuli to the centres
+in sleep is well known. Thus, David Hartley assigns as the second great
+source of dreams "states of the body."[79] But it is not so well known
+to what an extent our dreams may be influenced by stimuli acting on the
+exterior sense-organs. Let us first glance at the action of such
+external stimuli.
+
+
+_Action of External Stimuli._
+
+During sleep the eyes are closed, and consequently the action of
+external light on the retina impeded. Yet it is found that even under
+these circumstances any very bright light suddenly introduced is capable
+of stimulating the optic fibres, and of affecting consciousness. The
+most common form of this is the effect of bright moonlight, and of the
+early sun's rays. Krauss tells a funny story of his having once, when
+twenty-six years old, caught himself, on waking, in the act of
+stretching out his arms towards what his dream-fancy had pictured as the
+image of his mistress. When fully awake, this image resolved itself into
+the full moon.[80] It is not improbable, as Radestock remarks, that the
+rays of the sun or moon are answerable for many of the dreams of
+celestial glory which persons of a highly religious temperament are said
+to experience.
+
+External sounds, when not sufficient to rouse the sleeper, easily
+incorporate themselves into his dreams. The ticking of a watch, the
+stroke of a clock, the hum of an insect, the song of a bird, the patter
+of rain, are common stimuli to the dream-phantasy. M. Alf. Maury tells
+us, in his interesting account of the series of experiments to which he
+submitted himself in order to ascertain the result of external
+stimulation on the mind during sleep, that when a pair of tweezers was
+made to vibrate near his ear, he dreamt of bells, the tocsin, and the
+events of June, 1848.[81] Most of us, probably, have gone through the
+experience of impolitely falling asleep when some one was reading to us,
+and of having dream-images suggested by the sounds that were still
+indistinctly heard. Scherner gives an amusing case of a youth who was
+permitted to whisper his name into the ear of his obdurate mistress,
+the consequence of which was that the lady contracted a habit of
+dreaming about him, which led to a felicitous change of feeling on her
+part.[82]
+
+The two lower senses, smell and taste, seem to play a less-important
+part in the production of dream-illusions. Radestock says that the odour
+of flowers in a room easily leads to visual images of hot-houses,
+perfumery shops, and so on; and it is probable that the contents of the
+mouth may occasionally act as a stimulus to the organ of taste, and so
+give rise to corresponding dreams. As Radestock observes, these lower
+sensations do not commonly make known their quality to the sleeper's
+mind. They become transformed at once into visual, instead of into
+olfactory or gustatory percepts. That is to say, the dreamer does not
+imagine himself smelling or tasting, but seeing an object.
+
+The contact of objects with the tactual organ is one of the best
+recognized causes of dreams. M. Maury found that when his lips were
+tickled, his dream-fancy interpreted the impression as of a pitch
+plaster being torn off his face. An unusual pressure on any part of the
+body, as, for example, from contact with a fellow-sleeper, is known to
+give rise to a well-marked variety of dream. Our own limbs may even
+appear as foreign bodies to our dream-imagination, when through pressure
+they become partly paralyzed. Thus, on one occasion, I awoke from a
+miserable dream, in which I felt sure I was grasping somebody's hand in
+bed, and I was racked by terrifying conjectures as to who it might be.
+When fully awake, I discovered that I had been lying on my right side,
+and clasping the wrist of the right arm (which had been rendered
+insensible by the pressure of the body) with the left hand.
+
+In close connection with these stimuli of pressure are those of muscular
+movement, whether unimpeded or impeded. We need not enter into the
+difficult question how far the "muscular sense" is connected with the
+activity of the motor nerves, and how far with sensory fibres attached
+to the muscular or the adjacent tissues. Suffice it to say that an
+actual movement, a resistance to an attempted movement, or a mere
+disposition to movement, whether consequent on a surplus of motor energy
+or on a sensation of discomfort or fatigue in the part to be moved,
+somehow or other makes itself known to our minds, even when we are
+deprived of the assistance of vision. And these feelings of movement,
+impeded or unimpeded, are common initial impulses in our
+dream-experiences. It is quite a mistake to suppose that dreams are
+built up out of the purely passive sensations of sight and hearing. A
+close observation will show that in nearly every dream we imagine
+ourselves either moving among the objects we perceive or striving to
+move when some weighty obstacle obstructs us. All of us are familiar
+with the common forms of nightmare, in which we strive hopelessly to
+flee from some menacing evil, and this dream-experience, it may be
+presumed, frequently comes from a feeling of strain in the muscles, due
+to an awkward disposition of the limbs during sleep. The common
+dream-illusion of falling down a vast abyss is plausibly referred by
+Wundt to an involuntary extension of the foot of the sleeper.
+
+
+_Action of Internal Stimuli._
+
+Let us now pass from the action of stimuli lying outside the organism,
+to that of stimuli lying within the peripheral regions of the
+sense-organs. I have already spoken of the influence of subjective
+sensations of sight, hearing, etc., on the illusions of waking life, and
+it is now to be added that these sensations play an important part in
+our dream-life. Johannes Mueller lays great prominence on the part taken
+by ocular spectra in the production of dreams. As he observes, the
+apparent rays of light, light-patches, mists of light, and so on, due to
+changes of blood-pressure in the retina, only manifest themselves
+clearly when the eyes are closed and the more powerful effect of the
+external stimulus cut off. These subjective spectra come into prominence
+in the sleepy condition, giving rise to what M. Maury calls
+"hallucinations hypnagogiques," and which he regards (after Gruithuisen)
+as the chaos out of which the dream-cosmos is evolved.[83] They are
+pretty certainly the starting-point in those picturesque dreams in which
+figure a number of bright objects, such as beautiful birds, butterflies,
+flowers, or angels.
+
+That the visual images of our sleep do often involve the peripheral
+regions of the organ of sight, seems to be proved by the singular fact
+that they sometimes persist after waking. Spinoza and Jean Paul Richter
+both experienced this survival of dream-images. Still more pertinent is
+the fact that the effects of retinal fatigue are producible by
+dream-images. The physiologist Gruithuisen had a dream, in which the
+principal feature was a violet flame, and which left behind it, _after
+waking_, for an appreciable duration, a complementary image of a yellow
+spot.[84]
+
+Subjective auditory sensations appear to be much less frequent causes of
+dream-illusions than corresponding visual sensations. Yet the rushing,
+roaring sound caused by the circulation of the blood in the ear is,
+probably, a not uncommon starting-point in dreams. With respect to
+subjective sensations of smell and taste, there is little to be said. On
+the other hand, subjective sensations due to varying conditions in the
+skin are a very frequent exciting cause of dreams. Variations in the
+state of tension of the skin, brought about by alteration of position,
+changes in the character of the circulation, the irradiation of heat to
+the skin or the loss of the same, chemical changes,--these are known to
+give rise to a number of familiar sensations, including those of
+tickling, itching, burning, creeping, and so on; and the effects of
+these sensations are distinctly traceable in our dreams. For example,
+the exposure of a part of the body through a loss of the bed-clothes is
+a frequent excitant of distressing dreams. A cold foot suggests that the
+sleeper is walking over snow or ice. On the other hand, if the cold foot
+happens to touch a warm part of the body, the dream-fancy constructs
+images of walking on burning lava, and so on.
+
+These sensations of the skin naturally conduct us to the organic
+sensations as a whole; that is to say, the feelings connected with the
+varying condition of the bodily organs. These include the feelings which
+arise in connection with the processes of digestion, respiration, and
+circulation, and the condition of various organs according to their
+state of nutrition, etc. During our waking life these organic feelings
+coalesce for the most part, forming as the "vital sense" an obscure
+background for our clear discriminative consciousness, and only come
+forward into this region when very exceptional in character, as when
+respiration or digestion is impeded, or when we make a special effort of
+attention to single them out.[85] When we are asleep, however, and the
+avenues of external perception are closed, they assume greater
+prominence and distinctness. The centres, no longer called upon to react
+on stimuli coming from without the organism, are free to react on
+stimuli coming from its hidden recesses. So important a part, indeed, do
+these organic feelings take in the dream-drama, that some writers are
+disposed to regard them as the great, if not the exclusive, cause of
+dreams. Thus, Schopenhauer held that the excitants of dreams are
+impressions received from the internal regions of the organism through
+the sympathetic nervous system.[86]
+
+It is hardly necessary, perhaps, to give many illustrations of the
+effect of such organic sensations on our dreams. Among the most common
+provocatives of dreams are sensations connected with a difficulty in
+breathing, due to the closeness of the air or to the pressure of the
+bed-clothes on the mouth. J. Boerner investigated the influence of these
+circumstances by covering with the bed-clothes the mouth and a part of
+the nostrils of persons who were sound asleep. This was followed by a
+protraction of the act of breathing, a reddening of the face, efforts to
+throw off the clothes, etc. On being roused, the sleeper testified that
+he had experienced a nightmare, in which a horrid animal seemed to be
+weighing him down.[87] Irregularity of the heart's action is also a
+frequent cause of dreams. It is not improbable that the familiar
+dream-experience of flying arises from disturbances of the respiratory
+and circulatory movements.
+
+Again, the effects of indigestion, and more particularly stomachic
+derangement, on dreams are too well known to require illustration. It
+may be enough to allude to the famous dream which Hood traces to an
+excessive indulgence at supper. It is known that the varying condition
+of the organs of secretion influences our dream-fancy in a number of
+ways.
+
+Finally, it is to be observed that an injury done to any part of the
+organism is apt to give rise to appropriate dream-images. In this way,
+very slight disturbances which would hardly affect waking consciousness
+may make themselves felt during sleep. Thus, for example, an incipient
+toothache has been known to suggest that the teeth are being
+extracted.[88]
+
+It is worth observing that the interpretation of these various orders of
+sensations by the imagination of the dreamer takes very different forms
+according to the person's character, previous experience, ruling
+emotions, and so on. This is what is meant by saying that during sleep
+every man has a world of his own, whereas, when awake, he shares in the
+common world of perception.
+
+
+_Dream-Exaggeration._
+
+It is to be noticed, further, that this interpretation of sensation
+during sleep is uniformly a process of exaggeration.[89] The exciting
+causes of the feeling of discomfort, for example, are always absurdly
+magnified. The reason of this seems to be that, owing to the condition
+of the mind during sleep, the nature of the sensation is not clearly
+recognizable. Even in the case of familiar external impressions, such as
+the sound of the striking of a clock, there appears to be wanting that
+simple process of reaction by which, in a waking condition of the
+attention, a sense-impression is instantly discriminated and classed. In
+sleep, as in the artificially induced hypnotic condition, the slighter
+differences of quality among sensations are not clearly recognized. The
+activity of the higher centres, which are concerned in the finer
+processes of discrimination and classification, being greatly reduced,
+the impression may be said to come before consciousness as something
+novel and unfamiliar. And just as we saw that in waking life novel
+sensations agitate the mind, and so lead to an exaggerated mode of
+interpretation; so here we see that what is unfamiliar disturbs the
+mind, rendering it incapable of calm attention and just interpretation.
+
+This failure to recognize the real nature of an impression is seen most
+conspicuously in the case of the organic sensations. As I have remarked,
+these constitute for the most part, in waking life, an undiscriminated
+mass of obscure feeling, of which we are only conscious as the mental
+tone of the hour. And in the few instances in which we do attend to them
+separately, whether through their exceptional intensity or in
+consequence of an extraordinary effort of discriminative attention, we
+can only be said to perceive them, that is, recognize their local
+origin, very vaguely. Hence, when asleep, these sensations get very
+oddly misinterpreted.
+
+The localization of a bodily sensation in waking life means the
+combination of a tactual and a visual image with the sensation. Thus, my
+recognition of a twinge of toothache as coming from a certain tooth,
+involves representations of the active and passive sensations which
+touching and looking at the tooth would yield me. That is to say, the
+feeling instantly calls up a compound mental image exactly answering to
+a visual percept. This holds good in dream-interpretation too; the
+interpretation is effected by means of a visual image. But since the
+feeling is only very vaguely recognized, this visual image does not
+answer to the bodily part concerned. Instead of this, the fancy of the
+dreamer constructs some visual image which bears a vague resemblance to
+the proper one, and is generally, if not always, an exaggeration of this
+in point of extensive magnitude, etc. For example, a sensation arising
+from pressure on the bladder, being dimly connected with the presence of
+a fluid, calls up an image of a flood, and so on.
+
+This mode of dream-interpretation has by some writers been erected into
+the typical mode, under the name of dream-symbolism. Thus Scherner, in
+his interesting though somewhat fanciful work, _Das Leben des Traumes_,
+contends that the various regions of the body regularly disclose
+themselves to the dream-fancy under the symbol of a building or group of
+buildings; a pain in the head calling up, for example, the image of
+spiders on the ceiling, intestinal sensations exciting an image of a
+narrow alley, and so on. Such theories are clearly an exaggeration of
+the fact that the localization of our bodily sensations during sleep is
+necessarily imperfect.[90]
+
+In many cases the image called up bears on its objective side no
+discoverable resemblance to that of the bodily region or the exciting
+cause of the sensation. Here the explanation must be looked for in the
+subjective side of the sensation and mental image, that is to say, in
+their emotional quality, as pleasurable or painful, distressing,
+quieting, etc. It is to be observed, indeed, that in natural sleep, as
+in the condition known as hypnotism, while differences of specific
+quality in the sense-impressions are lost, the broad difference of the
+pleasurable and the painful is never lost. It is, in fact, the
+subjective emotional side of the sensation that uniformly forces itself
+into consciousness. This being so, it follows that, speaking generally,
+the sensations of sleep, both external and internal, or organic, will be
+interpreted by what G.H. Lewes has called "an analogy of feeling;" that
+is to say, by means of a mental image having some kindred emotional
+character or colouring.
+
+Now, the analogy between the higher emotional and the bodily states is a
+very close one. A sensation of obstruction in breathing has its exact
+analogue in a state of mental embarrassment, a sensation of itching its
+counterpart in mental impatience, and so on. And since these emotional
+experiences are deeper and fuller than the sensations, the tendency to
+exaggerate the nature and causes of these last would naturally lead to
+an interpretation of them by help of these experiences. In addition to
+this, the predominance of visual imagery in sleep would aid this
+transformation of a bodily sensation into an emotional experience, since
+visual perceptions have, as their accompaniments of pleasure and pain,
+not sensations, but emotions.[91]
+
+Since in this vague interpretation of bodily sensation the actual
+impression is obscured, and not taken up as an integral part into the
+percept, it is evident that we cannot, strictly speaking, call the
+process an imitation of an act of perception, that is to say, an
+illusion. And since, moreover, the visual image by which the sensation
+is thus displaced appears as a present object, it would, of course, be
+allowable to speak of this as an hallucination. This substitution of a
+more or less analogous visual image for that appropriate to the
+sensation forms, indeed, a transition from dream-illusion, properly so
+called, to dream-hallucination.
+
+
+_Dream-Hallucinations._
+
+On the physical side, these hallucinations answer to cerebral
+excitations which are central or automatic, not depending on movements
+transmitted from the periphery of the nervous system. Of these
+stimulations some appear to be direct, and due to unknown influences
+exerted by the state of nutrition of the cerebral elements, or the
+action of the contents of the blood-vessels on these elements.
+
+
+_Effects of Direct Central Stimulation._
+
+That such action does prompt a large number of dream-images may be
+regarded as fairly certain. First of all, it seems impossible to account
+for all the images of dream-fancy as secondary phenomena connected by
+links of association with the foregoing classes of sensation. However
+fine and invisible many of the threads which hold together our ideas may
+be, they will hardly explain the profusion and picturesque variety of
+dream-imagery. Secondly, we are able in certain cases to infer with a
+fair amount of certainty that a dream-image is due to such central
+stimulation. The common occurrence that we dream of the more stirring
+events, the anxieties and enjoyments of the preceding day, appears to
+show that when the cerebral elements are predisposed to a certain kind
+of activity, as they are after having been engaged for some time in this
+particular work, they are liable to be excited by some stimulus brought
+directly to bear on them during sleep. And if this is so, it is not
+improbable that many of the apparently forgotten images of persons and
+places which return with such vividness in dreams are excited by a mode
+of stimulation which is for the greater part confined to sleep. I say
+"for the greater part," because even in our indolent, listless moments
+of waking existence such seemingly forgotten ideas sometimes return as
+though by a spontaneous movement of their own and by no discoverable
+play of association.
+
+It may be well to add that this immediate revival of impressions
+previously received by the brain includes not only the actual
+perceptions of waking life, but also the ideas derived from others, the
+ideal fancies supplied by works of fiction, and even the images which
+our unaided waking fancy is wont to shape for itself. Our daily
+conjectures as to the future, the communications to us by others of
+their thoughts, hopes, and fears,--these give rise to numberless vague
+fugitive images, any one of which may become distinctly revived in
+sleep.[92] This throws light on the curious fact that we often dream of
+experiences and events quite unlike those of our individual life. Thus,
+for example, the common construction by the dream-fancy of the
+experience of flight in mid-air, and the creation of those weird forms
+which the terror of a nightmare is wont to bring in its train, seem to
+point to the past action of waking fancy. To imagine one's self flying
+when looking at a bird is probably a common action with all persons, at
+least in their earlier years, and images of preternaturally horrible
+beings are apt to be supplied to most of us some time during life by
+nurses or by books.
+
+
+_Indirect Central Stimulation._
+
+Besides these direct central stimulations, there are others which, in
+contradistinction, may be called indirect, depending on some previous
+excitation. These are, no doubt, the conditions of a very large number
+of our dream-images. There must, of course, be some primary cerebral
+excitation, whether that of a present peripheral stimulation, or that
+which has been termed central and spontaneous; but when once this first
+link of the imaginative chain is supplied, other links may be added in
+large numbers through the operation of the forces of association. One
+may, indeed, safely say that the large proportion of the contents of
+every dream arise in this way.
+
+The very simplest type of dream excited by a present sensation contains
+these elements. To take an example, I once dreamt, as a consequence of
+the loud barking of a dog, that a dog approached me when lying down, and
+began to lick my face. Here the play of the associative forces was
+apparent: a mere sensation of sound called up the appropriate visual
+image, this again the representation of a characteristic action, and so
+on. So it is with the dreams whose first impulse is some central or
+spontaneous excitation. A momentary sight of a face or even the mention
+of a name during the preceding day may give the start to dream-activity;
+but all subsequent members of the series of images owe their revival to
+a tension, so to speak, in the fine threads which bind together, in so
+complicated a way, our impressions and ideas.
+
+Among the psychic accompaniments of these central excitations visual
+images, as already hinted, fill the most conspicuous place. Even
+auditory images, though by no means absent, are much less numerous than
+visual. Indeed, when there are the conditions for the former, it
+sometimes happens that the auditory effect transforms itself into a
+visual effect. An illustration of this occurred in my own experience.
+Trying to fall asleep by means of the well-known device of counting, I
+suddenly found myself losing my hold on the faint auditory effects, my
+imagination transforming them into a visual spectacle, under the form of
+a path of light stretching away from me, in which the numbers appeared
+under the grotesque form of visible objects, tumbling along in glorious
+confusion.
+
+Next to these visual phantasms, certain motor hallucinations seem to be
+most prominent in dreams. By a motor hallucination, I mean the illusion
+that we are actually moving when there is no peripheral excitation of
+the motor organ. Just as the centres concerned in passive sensation are
+susceptible of central stimulation, so are the centres concerned in
+muscular sensation. A mere impulse in the centres of motor innervation
+(if we assume these to be the central seat of the muscular feelings) may
+suffice to give rise to a complete representation of a fully executed
+movement. And thus in our sleep we seem to walk, ride, float, or fly.
+
+The most common form of motor hallucination is probably the vocal. In
+the social encounters which make up so much of our sleep-experience, we
+are wont to be very talkative. Now, perhaps, we find ourselves zealously
+advocating some cause, now very fierce in denunciation, now very amusing
+in witty repartee, and so on. This imagination of ourselves as speaking,
+as distinguished from that of hearing others talking, must, it is clear,
+involve the excitation of the structures engaged in the production of
+the muscular feelings which accompany vocal action, as much as, if not
+more than, the auditory centres. And the frequency of this kind of
+dream-experience may be explained, like that of visual imagery, by the
+habits of waking life. The speech impulse is one of the most deeply
+rooted of all our impulses, and one which has been most frequently
+exercised in waking life.
+
+_Combination of Dream-Elements._
+
+It is commonly said that dreams are a grotesque dissolution of all
+order, a very chaos and whirl of images without any discoverable
+connection. On the other hand, a few writers claim for the mind in sleep
+a power of arranging and grouping its incongruous elements in definite
+and even life-like pictures. Each of these views is correct within
+certain limits; that is to say, there are dreams in which the strangest
+disorder seems to prevail, and others in which one detects the action of
+a central control. Yet, speaking generally, sequences of dream-images
+will be found to be determined by certain circumstances and laws, and so
+far not to be haphazard or wholly chaotic. We have now to inquire into
+the laws of these successions; and, first of all, we may ask how far the
+known laws of association, together with the peculiar conditions of the
+sleeping state, are able to account for the various modes of
+dream-combination. We have already regarded mental association as
+furnishing a large additional store of dream-imagery; we have now to
+consider it as explaining the sequences and concatenations of our
+dream-elements.
+
+
+_Incoherence of Dreams._
+
+First of all, then, let us look at the chaotic and apparently lawless
+side of dreaming, and see whether any clue is discoverable to the centre
+of this labyrinth. In the case of all the less elaborately ordered
+dreams, in which sights and sounds appear to succeed one another in the
+wildest dance (which class of dreams probably belongs to the deeper
+stages of sleep), the mind may with certainty be regarded as purely
+passive, and the mode of sequence may be referred to the action of
+association complicated by the ever-recurring introduction of new
+initial impulses, both peripheral and central. These are the dreams in
+which we are conscious of being perfectly passive, either as spectators
+of a strange pageant, or as borne away by some apparently extraneous
+force through a series of the most diverse experiences. The flux of
+images in these dreams is very much the same as that in certain waking
+conditions, in which we relax attention, both external and internal, and
+yield ourselves wholly to the spontaneous play of memory and fancy.
+
+It is plain at a glance that the simultaneous concurrence of wholly
+disconnected initial impulses will serve to impress a measure of
+disconnectedness on our dream-images. From widely remote parts of the
+organism there come impressions which excite each its peculiar visual or
+other image according as its local origin or its emotional tone is the
+more distinctly present to consciousness. Now it is a subjective ocular
+sensation suggesting a bouquet of lovely flowers, and close on its heels
+comes an impression from the organs of digestion suggesting all manner
+of obstacles, and so our dream-fancy plunges from a vision of flowers to
+one of dreadful demons.
+
+Let us now look at the way in which the laws of association working on
+the incongruous elements thus cast up into our dream-consciousness, will
+serve to give a yet greater appearance of disorder and confusion to our
+dream-combinations. According to these laws, any idea may, under
+certain circumstances, call up another, if the corresponding impressions
+have only once occurred together, or if the ideas have any degree of
+resemblance, or, finally, if only they stand in marked contrast with one
+another. Any accidental coincidence of events, such as meeting a person
+at a particular foreign resort, and any insignificant resemblance
+between objects, sounds, etc., may thus supply a path, so to speak, from
+fact to dream-fancy.
+
+In our waking states these innumerable paths of association are
+practically closed by the supreme energy of the coherent groups of
+impressions furnished us from the world without through our organs of
+sense, and also by the volitional control of internal thought in
+obedience to the pressure of practical needs and desires. In dream-life
+both of these influences are withdrawn, so that delicate threads of
+association, which have no chance of exerting their pull, so to speak,
+in our waking states, now make known their hidden force. Little wonder,
+then, that the filaments which bind together these dream-successions
+should escape detection, since even in our waking thought we so often
+fail to see the connection which makes us pass in recollection from a
+name to a visible scene or perhaps to an emotional vibration.
+
+It is worth noting that the origin of an association is often to be
+looked for in one of those momentary half-conscious acts of waking
+imagination to which reference has already been made. A friend, for
+example, has been speaking to us of some common acquaintance, remarking
+on his poor health. The language calls up, vaguely, a visual
+representation of the person sinking in health and dying. An
+association will thus be formed between this person and the idea of
+death. A night or two after, the image of this person somehow recurs to
+our dream-fancy, and we straightway dream that we are looking at his
+corpse, watching his funeral, and so on. The links of the chain which
+holds together these dream-images were really forged, in part, in our
+waking hours, though the process was so rapid as to escape our
+attention. It may be added, that in many cases where a juxtaposition of
+dream-images seems to have no basis in waking life, careful reflection
+will occasionally bring to light some actual conjunction of impressions
+so momentary as to have faded from our recollection.
+
+We must remember, further, how great an apparent disorder will invade
+our imaginative dream-life when the binding force of resemblance has
+unchecked play. In waking thought we have to connect things according to
+their essential resemblances, classifying objects and events for
+purposes of knowledge or action, according to their widest or their most
+important points of similarity. In sleep, on the contrary, the slightest
+touch of resemblance may engage the mind and affect the direction of
+fancy. In a sense we may be said, when dreaming, to discover mental
+affinities between impressions and feelings, including those subtle
+links of emotional analogy of which I have already spoken. This effect
+is well illustrated in a dream recorded by M. Maury, in which he passed
+from one set of images to another through some similarity of names, as
+that between _corps_ and _cor_. Such a movement of fancy would, of
+course, be prevented in full waking consciousness by a predominant
+attention to the meaning of the sounds.
+
+It will be possible, I think, after a habit of analyzing one's dreams in
+the light of preceding experience has been formed, to discover in a good
+proportion of cases some hidden force of association which draws
+together the seemingly fortuitous concourse of our dream-atoms. That we
+should expect to do so in every case is unreasonable, since, owing to
+the numberless fine ramifications which belong to our familiar images,
+many of the paths of association followed by our dream-fancy cannot be
+afterwards retraced.
+
+To illustrate the odd way in which our images get tumbled together
+through the action of occult association forces, I will record a dream
+of my own. I fancied I was at the house of a distinguished literary
+acquaintance, at her usual reception hour. I expected the friends I was
+in the habit of meeting there. Instead of this, I saw a number of
+commonly dressed people having tea. My hostess came up and apologized
+for having asked me into this room. It was, she said, a tea-party which
+she prepared for poor people at sixpence a head. After puzzling over
+this dream, I came to the conclusion that the missing link was a verbal
+one. A lady who is a connection of my friend, and bears the same name,
+assists her sister in a large kind of benevolent scheme. I may add that
+I had not, so far as I could recollect, had occasion very recently to
+think of this benevolent friend, but I had been thinking of my literary
+friend in connection with her anticipated return to town.
+
+In thus seeking to trace, amid the superficial chaos of dream-fancy,
+its hidden connections, I make no pretence to explain why in any given
+case these particular paths of association should be followed, and more
+particularly why a slender thread of association should exert a pull
+where a stronger cord fails to do so. To account for this, it would be
+necessary to call in the physiological hypothesis that among the nervous
+elements connected with a particular element, _a_, already excited,
+some, as _m_ and _n_, are at the moment, owing to the state of their
+nutrition or their surrounding influences, more powerfully predisposed
+to activity than other elements, as _b_ and _c_.
+
+The subject of association naturally conducts us to the second great
+problem in the theory of dreams--the explanation of the order in which
+the various images group themselves in all our more elaborate dreams.
+
+
+_Coherence of Dreams._
+
+A fully developed dream is a complex of many distinct illusory
+sense-presentations: in this respect it differs from the illusions of
+normal waking life, which are for the most part single and isolated. And
+this complex of quasi-presentations appears somehow or other to fall
+together into one whole scene or series of events, which, though it may
+be very incongruous and absurdly impossible from a waking point of view,
+nevertheless makes a single object for the dreamer's internal vision,
+and has a certain degree of artistic unity. This plastic force, which
+selects and binds together our unconnected dream-images, has frequently
+been referred to as a mysterious spiritual faculty, under the name of
+"creative fancy." Thus Cudworth remarks, in his _Treatise concerning
+Eternal and Immutable Morality_: "That dreams are many times begotten by
+the phantastical power of the soul itself ... is evident from the
+orderly connection and coherence of imaginations which many times are
+continued in a long chain or series." One may find a good deal of
+mystical writing on the nature and activity of this faculty, especially
+in German literature. The explanation of this element of organic unity
+in dreams is, it may be safely said, the crux in the science of dreams.
+That the laws of psychology help us to understand the sequences of
+dream-images, we have seen. What we have now to ask is whether these
+laws throw any light on the orderly grouping of the elements so brought
+up in consciousness in the form of a connected experience.
+
+It is to be remarked at the outset that a singular kind of unity is
+sometimes given to our dream-combinations by a total or partial
+coalescence of different images. The conditions of such coalescence have
+been referred to already.[93] Simultaneous impressions or images will
+always tend to coalesce with a force which varies directly as the degree
+of their similarity. Sometimes this coalescence is instantaneous and not
+made known to consciousness. Thus, Radestock suggests that if the mind
+of the sleeper is simultaneously invaded by an unpleasant sensation
+arising out of some disturbance of the functions of the skin, and a
+subjective visual sensation, the resulting mental image may be a
+combination of the two, under the form of a caterpillar creeping over
+the bodily surface. And the coalescence may even be prepared by
+sub-conscious operations of waking imagination. Thus, for example, I
+once spoke about the cheapness of hares to a member of my family, who
+somewhat grimly suggested that they were London cats. I did not dwell on
+the idea, but the following night I dreamt that I saw a big hybrid
+creature, half hare, half cat, sniffing about a cottage. As it stood on
+its hind legs and took a piece of food from a window-ledge, I became
+sure that it was a cat. Here it is plain that the cynical observation of
+my relative had, at the moment, partially excited an image of this
+feline hare. In some dreams, again, we may become aware of the process
+of coalescence, as when persons who at one moment were seen to be
+distinct appear to our dream-fancy to run together in some third person.
+
+A very similar kind of unification takes place between sequent images
+under the form of transformation. When two images follow one another
+closely, and have anything in common, they readily assume the form of a
+transmutation. There is a sort of overlapping of the mental images, and
+so an appearance of continuity produced in some respects analogous to
+that which arises in the wheel-of-life (thaumatrope) class of
+sense-illusions. This would seem to account for the odd transformations
+of personality which not unfrequently occur in dreams, in which a person
+appears, by a kind of metempsychosis, to transfer his physical ego to
+another, and in which the dreamer's own bodily phantom plays similar
+freaks. And the same principle probably explains those dissolving-view
+effects which are so familiar an accompaniment of dream-scenery.[94]
+
+But passing from this exceptional kind of unity in dreams, let us
+inquire how the heterogeneous elements of our dream-fancy become ordered
+and arranged when they preserve their separate existence. If we look
+closely at the structure of our more finished dreams, we find that the
+appearance of harmony, connectedness, or order, may be given in one of
+two ways. There may, first of all, be a subjective harmony, the various
+images being held together by an emotional thread. Or there may,
+secondly, be an objective harmony, the parts of the dream, though
+answering to no particular experiences of waking life, bearing a certain
+resemblance to our habitual modes of experience. Let us inquire into the
+way in which each kind of order is brought about.
+
+
+_Lyrical Element in Dreams._
+
+The only unity that belongs to many of our dreams is a subjective
+emotional unity. This is the basis of harmony in lyrical poetry, where
+the succession of images turns mainly on their emotional colouring.
+Thus, the images that float before the mind of the Poet Laureate, in his
+_In Memoriam_, clearly have their link of connection in their common
+emotional tone, rather than in any logical continuity. Dreaming has been
+likened to poetic composition, and certainly many of our dreams are
+built upon a groundwork of lyrical feeling. They might be marked off,
+perhaps, as our lyrical dreams.
+
+The way in which this emotional force acts in these cases has already
+been hinted at. We have seen that the analogy of feeling is a common
+link between dream-images. Now, if any shade of feeling becomes fixed
+and dominant in the mind, it will tend to control all the images of the
+time, allowing certain congruous ones to enter, and excluding
+others.[95] If, for example, a feeling of distress occupies the mind,
+distressing images will have the advantage in the struggle for existence
+which goes on in the world of mind as well as in that of matter. We may
+say that attention, which is here wholly a passive process, is
+controlled by the emotion of the time, and bent in the direction of
+congruent or harmonious images.
+
+Now, a ground-tone of feeling of a certain complexion, answering to the
+sum of sensations arising in connection with the different organic
+processes of the time, is a very frequent foundation of our
+dream-structure. So frequent is it, indeed, that one might almost say
+there is no dream in which it is not one great determining factor. The
+analysis of a very large number of dreams has convinced me that traces
+of this influence are discoverable in a great majority.
+
+I will give a simple illustration of this lyrical type of dream. A
+little girl of about four years and three-quarters went with her parents
+to Switzerland. On their way she was taken to the cathedral at
+Strasburg, and saw the celebrated clock strike, and the figures of the
+Apostles come out, etc. In Switzerland she stayed at Gimmelwald, near
+Muerren, opposite a fine mass of snowy mountains. One morning she told
+her father that she had had "such a lovely dream." She fancied she was
+on the snow-peaks with her nurse, and walked on to the sky. There came
+out of the sky "such beautiful things," just like the figures of the
+clock. This vision of celestial things was clearly due to the fact that
+both the clock and the snow-peaks touching the blue sky had powerfully
+excited her imagination, filling her with much the same kind of emotion,
+namely, wonder, admiration, and longing to reach an inaccessible height.
+
+Our feelings commonly have a gradual rise and fall, and the organic
+sensations which so often constitute the emotional basis of our lyrical
+dreams generally have stages of increasing intensity. Moreover, such a
+persistent ground-feeling becomes reinforced by the images which it
+sustains in consciousness. Hence a certain _crescendo_ character in our
+emotional dreams, or a gradual rise to some culminating point or climax.
+
+This phase of dream can be illustrated from the experience of the same
+little girl. When just five years old, she was staying at Hampstead,
+near a church which struck the hours somewhat loudly. One morning she
+related the following dream to her father (I use her own language). The
+biggest bells in the world were ringing; when this was over the earth
+and houses began to tumble to pieces; all the seas, rivers, and ponds
+flowed together, and covered all the land with black water, as deep as
+in the sea where the ships sail; people were drowned; she herself flew
+above the water, rising and falling, fearing to fall in; she then saw
+her mamma drowned, and at last flew home to tell her papa. The gradual
+increase of alarm and distress expressed in this dream, having its
+probable cause in the cumulative effect of the disturbing sound of the
+church bells, must be patent to all.
+
+The following rather comical dream illustrates quite as clearly the
+growth of a feeling of irritation and vexation, probably connected with
+the development of some slightly discomposing organic sensation. I
+dreamt I was unexpectedly called on to lecture to a class of young
+women, on Herder. I began hesitatingly, with some vague generalities
+about the Augustan age of German literature, referring to the three
+well-known names of Lessing, Schiller, and Goethe. Immediately my
+sister, who suddenly appeared in the class, took me up, and said she
+thought there was a fourth distinguished name belonging to this period.
+I was annoyed at the interruption, but said, with a feeling of triumph,
+"I suppose you mean Wieland?" and then appealed to the class whether
+there were not twenty persons who knew the names I had mentioned to one
+who knew Wieland's name. Then the class became generally disorderly. My
+feeling of embarrassment gained in depth. Finally, as a climax, several
+quite young girls, about ten years and less, came and joined the class.
+The dream broke off abruptly as I was in the act of taking these
+children to the wife of an old college tutor, to protest against their
+admission.
+
+It is worth noting, perhaps, that in this evolution of feeling in
+dreaming the quality of the emotion may vary within certain limits. One
+shade of feeling may be followed by another and kindred shade, so that
+the whole dream still preserves a degree, though a less obvious degree,
+of emotional unity. Thus, for example, a lady friend of mine once dreamt
+that she was in church, listening to a well-known novelist of the more
+earnest sort, preaching. A wounded soldier was brought in to be shot,
+because he was mortally wounded, and had distinguished himself by his
+bravery. He was then shot, but not killed, and, rolling over in agony,
+exclaimed, "How long!" The development of an extreme emotion of horror
+out of the vague feeling of awe which is associated with a church, gives
+a curious interest to this dream.
+
+
+_Verisimilitude in Dreams._
+
+I must not dwell longer on this emotional basis of dreams, but pass to
+the consideration of the second and objective kind of unity which
+characterizes many of our more elaborate dream-performances. In spite of
+all that is fitful and grotesque in dream-combination, it still
+preserves a distant resemblance to our actual experience. Though no
+dream reproduces a particular incident or chain of incidents in this
+experience, though the dream-fancy invariably transforms the particular
+objects, relations, and events of waking life, it still makes the order
+of our daily experience its prototype. It fashions its imaginary world
+on the model of the real. Thus, objects group themselves in space, and
+act on one another conformably to these perceived space-relations;
+events succeed one another in time, and are often seen to be connected;
+men act from more or less intelligible motives, and so on. In this way,
+though the dream-fancy sets at nought the particular relations of our
+experience, it respects the general and constant relations. How are we
+to account for this?
+
+It is said by certain philosophers that this superposition of the
+relations of space, time, causation, etc., on the products of our
+dream-fancy is due to the fact that all experience arises by a synthesis
+of mental forms with the chaotic matter of sense-impressions. These
+philosophers allow, however, that all particular connections are
+determined by experience. Accordingly, what we have to do here is to
+inquire how far this scientific method of explaining mental connections
+by facts of experience will carry us. In other words, we have to ask
+what light can be thrown on these tendencies of dream-imagination by
+ascertained psychological laws, and more particularly by what are known
+as the laws of association.
+
+These laws tell us that of two mental phenomena which occur together,
+each will tend to recall the other whenever it happens to be revived. On
+the physiological side, this means that any two parts of the nervous
+structures which have acted together become in some way connected, so
+that when one part begins to work the other will tend to work also. But
+it is highly probable that a particular structure acts in a great many
+different ways. Thus, it may be stimulated by unlike modes of stimuli,
+or it may enter into very various connections with other structures.
+What will follow from this? One consequence would appear to be that
+there will be developed an organic connection between the two
+structures, of such a kind that whenever one is excited the other will
+be disposed to act somehow and anyhow, even when there is nothing in the
+present mode of activity of the first structure to determine the second
+to act in some one definite way, in other words, when this mode of
+activity is, roughly speaking, novel.
+
+Let me illustrate this effect in one of the simplest cases, that of the
+visual organ. If, when walking out on a dark night, a few points in my
+retina are suddenly stimulated by rays of light, and I recognize some
+luminous object in a corresponding direction, I am prepared to see
+something above and below, to the right and to the left of this object.
+Why is this? There may from the first have been a kind of innate
+understanding among contiguous optic fibres, predisposing them to such
+concerted action. But however this be, this disposition would seem to
+have been largely promoted by the fact that, throughout my experience,
+the stimulation of any retinal point has been connected with that of
+adjoining points, either simultaneously by some second object, or
+successively by the same object as the eye moves over it, or as the
+object itself moves across the field of vision.
+
+When, therefore, in sleep any part of the optic centres is excited in a
+particular way, and the images thus arising have their corresponding
+loci in space assigned to them, there will be a disposition to refer any
+other visual images which happen at the moment to arise in consciousness
+to adjacent parts of space. The character of these other images will be
+determined by other special conditions of the moment; their locality or
+position in space will be determined by this organic connection. We may,
+perhaps, call these tendencies to concerted action of some kind general
+associative dispositions.
+
+Just as there are such dispositions to united action among various parts
+of one organ of sense, so there may be among different organs, which are
+either connected originally in the infant organism, or have
+communications opened up by frequent coexcitation of the two. Such links
+there certainly are between the organs of taste and smell, and between
+the ear and the muscular system in general, and more particularly the
+vocal organ.[96] A new odour often sets us asking how the object would
+taste, and a series of sounds commonly disposes us to movement of some
+kind or another. How far there may be finer threads of connection
+between other organs, such as the eye and the ear, which do not betray
+themselves amid the stronger forces of waking mental life, one cannot
+say. Whatever their number, it is plain that they will exert their
+influence within the comparatively narrow limits of dream-life, serving
+to impress a certain character on the images which happen to be called
+up by special circumstances, and giving to the combination a slight
+measure of congruity. Thus, if I were dreaming that I heard some lively
+music, and at the same time an image of a friend was anyhow excited, my
+dream-fancy might not improbably represent this person as performing a
+sequence of rhythmic movements, such as those of riding, dancing, etc.
+
+A narrower field for these general associative dispositions may be found
+in the tendency, on the reception of an impression of a given character,
+to look for a certain kind of second impression; though the exact nature
+of this is unknown. Thus, for example, the form and colour of a new
+flower suggest a scent, and the perception of a human form is
+accompanied by a vague representation of vocal utterances. These general
+tendencies of association appear to me to be most potent influences in
+our dream-life. The many strange human forms which float before our
+dream-fancy are apt to talk, move, and behave like men and women in
+general, however little they resemble their actual prototypes, and
+however little individual consistency of character is preserved by each
+of them. Special conditions determine what they shall say or do; the
+general associative disposition accounts for their saying or doing
+something.
+
+We thus seem to find in the purely passive processes of association some
+ground for that degree of natural coherence and rational order which our
+more mature dreams commonly possess. These processes go far to explain,
+too, that odd mixture of rationality with improbability, of natural
+order and incongruity, which characterizes our dream-combinations.
+
+
+_Rational Construction in Dreams._
+
+Nevertheless, I quite agree with Herr Volkelt that association, even in
+the most extended meaning, cannot explain all in the shaping of our
+dream-pictures. The "phantastical power" which Cudworth talks about
+clearly includes something besides. It is an erroneous supposition that
+when we are dreaming there is a complete suspension of the voluntary
+powers, and consequently an absence of all direction of the intellectual
+processes. This supposition, which has been maintained by numerous
+writers, from Dugald Stewart downwards, seems to be based on the fact
+that we frequently find ourselves in dreams striving in vain to move the
+whole body or a limb. But this only shows, as M. Maury remarks in the
+work already referred to, that our volitions are frustrated through the
+inertia of our bodily organs, not that these volitions do not take
+place. In point of fact, the dreamer, not to speak of the somnambulist,
+is often conscious of voluntarily going through a series of actions.
+This exercise of volition is shown unmistakably in the well-known
+instances of extraordinary intellectual achievements in dreams, as
+Condillac's composition of a part of his _Cours d'Etudes_. No one would
+maintain that a result of this kind was possible in the total absence of
+intellectual action carefully directed by the will. And something of
+this same control shows itself in all our more fully developed dreams.
+
+One manifestation of this voluntary activity in sleep is to be found in
+those efforts of attention which not unfrequently occur. I have remarked
+that, speaking roughly and in relation to the waking condition, the
+state of sleep is marked by a subjection of the powers of attention to
+the force of the mental images present to consciousness. Yet something
+resembling an exercise of voluntary attention sometimes happens in
+sleep. The intellectual feats just spoken of, unless, indeed, they are
+referred to some mysterious unconscious mental operations, clearly
+involve a measure of volitional guidance. All who dream frequently are
+occasionally aware on awaking of having greatly exercised their
+attention on the images presented to them during sleep. I myself am
+often able to recall an effort to see beautiful objects, which
+threatened to disappear from my field of vision, or to catch faint
+receding tones of preternatural sweetness; and some dreamers allege that
+they are able to retain a recollection of the feeling of strain
+connected with such exercise of attention in sleep.
+
+The main function of this voluntary attention in dream-life is seen in
+the selection of those images which are to pass the threshold of clear
+consciousness. I have already spoken of a selective action brought about
+by the ruling emotion. In this case, the attention is held captive by
+the particular feeling of the moment. Also a selective process goes on
+in the case of the action of those associative dispositions just
+referred to. But in each of these cases the action of selective
+attention is comparatively involuntary, passive, and even unconscious,
+not having anything of the character of a conscious striving to compass
+some end. Besides this comparatively passive play of selective
+attention, there is an active play, in which there is a conscious wish
+to gain an end; in other words, the operation of a definite motive. This
+motive may be described as an intellectual impulse to connect and
+harmonize what is present to the mind. The voluntary kind of selection
+includes and transcends each of the involuntary kinds. It has as its
+result an imitation of that order which is brought about by what I have
+called the associative dispositions, only it consciously aims at this
+result. And it is a process controlled by a feeling, namely, the
+intellectual sentiment of consistency, which is not a mode of emotional
+excitement enthralling the will, but a calm motive, guiding the
+activities of attention. It thus bears somewhat the same relation to the
+emotional selection already spoken of, as dramatic creation bears to
+lyrical composition.
+
+This process of striving to seize some connecting link, or thread of
+order, is illustrated whenever, in waking life, we are suddenly brought
+face to face with an unfamiliar scene. When taken into a factory, we
+strive to arrange the bewildering chaos of visual impressions under some
+scheme, by help of which we are said to understand the scene. So, if on
+entering a room we are plunged in _medias res_ of a lively conversation,
+we strive to find a clue to the discussion. Whenever the meaning of a
+scene is not at once clear, and especially whenever there is an
+appearance of confusion in it, we are conscious of a painful feeling of
+perplexity, which acts as a strong motive to ever-renewed attention.[97]
+
+In touching on this intellectual impulse to connect the disconnected, we
+are, it is plain, approaching the question of the very foundations of
+our intellectual structure. That there is this impulse firmly rooted in
+the mature mind nobody can doubt; and that it manifests itself in early
+life in the child's recurring "Why?" is equally clear. But how we are to
+account for it, whether it is to be viewed as a mere result of the play
+of associated fragments of experience, or as something involved in the
+very process of the association of ideas itself, is a question into
+which I cannot here enter.
+
+What I am here concerned to show is that the search for consistency and
+connection in the manifold impressions of the moment is a deeply rooted
+habit of the mind, and one which is retained in a measure during sleep.
+When, in this state, our minds are invaded by a motley crowd of
+unrelated images, there results a disagreeable sense of confusion; and
+this feeling acts as a motive to the attention to sift out those
+products of the dream-fancy which may be made to cohere. When once the
+foundations of a dream-action are laid, new images must to some extent
+fit in with this; and here there is room for the exercise of a distinct
+impulse to order the chaotic elements of dream-fancy in certain forms.
+The perception of any possible relation between one of the crowd of new
+images ever surging above the level of obscure consciousness, and the
+old group at once serves to detain it. The concentration of attention on
+it, in obedience to this impulse to seek for an intelligible order, at
+once intensifies it and fixes it, incorporating it into the series of
+dream-pictures.
+
+Here is a dream which appears to illustrate this impulse to seek an
+intelligible order in the confused and disorderly. After being occupied
+with correcting the proofs of my volume on _Pessimism_, I dreamt that my
+book was handed to me by my publisher, fully illustrated with coloured
+pictures. The frontispiece represented the fantastic figure of a man
+gesticulating in front of a ship, from which he appeared to have just
+stepped. My publisher told me it was meant for Hamlet, and I immediately
+reflected that this character had been selected as a concrete example of
+the pessimistic tendency. I may add that, on awaking, I was distinctly
+aware of having felt puzzled when dreaming, and of having striven to
+read a meaning into the dream.
+
+The _rationale_ of this dream seems to me to be somewhat as follows. The
+image of the completed volume represented, of course, a recurring
+anticipatory image of waking life. The coloured plates were due probably
+to subjective optical sensations simultaneously excited, which were made
+to fit in (with or without an effort of voluntary attention) with the
+image of the book under the form of illustrations. But this stage of
+coherency did not satisfy the mind, which, still partly confused by the
+incongruity of coloured plates in a philosophic work, looked for a
+closer connection. The image of Hamlet was naturally suggested in
+connection with pessimism. The effort to discover a meaning in the
+pictures led to the fusion of this image with one of the subjective
+spectra, and in this way the idea of a Hamlet frontispiece probably
+arose.
+
+The whole process of dream-construction is clearly illustrated in a
+curious dream recorded by Professor Wundt.[98] Before the house is a
+funeral procession: it is the burial of a friend, who has in reality
+been dead for some time past. The wife of the deceased bids him and an
+acquaintance who happens to be with him go to the other side of the
+street and join the procession. After she has gone away, his companion
+remarks to him, "She only said that because the cholera rages over
+yonder, and she wants to keep this side of the street to herself." Then
+comes an attempt to flee from the region of the cholera. Returning to
+his house, he finds the procession gone, but the street strewn with
+rich nosegays; and he further observes crowds of men who seem to be
+funeral attendants, and who, like himself, are hastening to join the
+procession. These are, oddly enough, dressed in red. When hurrying on,
+it occurs to him that he has forgotten to take a wreath for the coffin.
+Then he wakes up with beating of the heart.
+
+The sources of this dream are, according to Wundt, as follows. First of
+all, he had, on the previous day, met the funeral procession of an
+acquaintance. Again, he had read of cholera breaking out in a certain
+town. Once more, he had talked about the particular lady with this
+friend, who had narrated facts which clearly proved her selfishness. The
+hastening to flee from the infected neighbourhood and to overtake the
+procession was prompted by the sensation of heart-beating. Finally, the
+crowd of red bier-followers, and the profusion of nosegays, owed their
+origin to subjective visual sensations, the "light-chaos" which often
+appears in the dark.
+
+Let us now see for a moment how these various elements may have become
+fused into a connected chain of events. First of all, it is clear that
+this dream is built up on a foundation of a gloomy tone of feeling,
+arising, as it would seem, from an irregularity of the heart's action.
+Secondly, it owes its special structure and its air of a connected
+sequence of events, to those tendencies, passive and active, to order
+the chaotic of which I have been speaking. Let us try to trace this out
+in detail.
+
+To begin with, we may suppose that the image of the procession occupies
+the dreamer's mind. From quite another source the image of the lady
+enters consciousness, bringing with it that of her deceased husband and
+of the friend who has recently been talking about her. These new
+elements adapt themselves to the scene, partly by the passive mechanism
+of associative dispositions, and partly, perhaps, by the activity of
+voluntary selection. Thus, the idea of the lady's husband would
+naturally recall the fact of his death, and this would fall in with the
+pre-existing scene under the form of the idea that he is the person who
+is now being buried. The next step is very interesting. The image of the
+lady is associated with the idea of selfish motives. This would tend to
+suggest a variety of actions, but the one which becomes a factor of the
+dream is that which is specially adapted to the pre-existing
+representations, namely, of the procession on the further side of the
+street, and the cholera (which last, like the image of the funeral, is,
+we may suppose, due to an independent central excitation). That is to
+say, the request of the lady, and its interpretation, are a _resultant_
+of a number of adaptative or assimilative actions, under the sway of a
+strong desire to connect the disconnected, and a lively activity of
+attention. Once more, the feeling of oppression of the heart, and the
+subjective stimulation of the optic nerve, might suggest numberless
+images besides those of anxious flight and of red-clad men and nosegays;
+they suggest these, and not others, in this particular case, because of
+the co-operation of the impulse of consistency, which, setting out with
+the pre-existing mental images, selects from among many tendencies of
+reproduction those which happen to chime in with the scene.
+
+
+_The Nature of Dream-Intelligence._
+
+It must not be supposed that this process of welding together the
+chaotic materials of our dreams is ever carried out with anything like
+the clear rational purpose of which we are conscious when seeking, in
+waking life, to comprehend some bewildering spectacle. At best it is a
+vague longing, and this longing, it may be added, is soon satisfied.
+There is, indeed, something, almost pathetic in the facility with which
+the dreamer's mind can be pacified with the least appearance of a
+connection. Just as a child's importunate "Why?" is often silenced by a
+ridiculous caricature of an explanation, so the dreamer's intelligence
+is freed from its distress by the least semblance of a uniting order.
+
+It thus remains true with respect even to our most coherent dreams, that
+there is a complete suspension, or at least a considerable retardation,
+of the highest operations of judgment and thought; also a great
+enfeeblement, to say the least of it, of those sentiments such as the
+feeling of consistency and the sense of the absurd which are so
+intimately connected with these higher intellectual operations.
+
+In order to illustrate how oddly our seemingly rational dreams
+caricature the operations of waking thought, I may, perhaps, be allowed
+to record two of my own dreams, of which I took careful note at the
+time.
+
+On the first occasion I went "in my dream" to the "Stores" in August,
+and found the place empty. A shopman brought me some large fowls. I
+asked their price, and he answered, "Tenpence a pound." I then asked
+their weight, so as to get an idea of their total cost, and he replied,
+"Forty pounds." Not in the least surprised, I proceeded to calculate
+their cost: 40x10=400/12=33-1/3. But, oddly enough, I took this quotient
+as pence, just as though I had not already divided by 12, and so made
+the cost of a fowl to be 2s. 9d., which seemed to me a fair enough
+price.
+
+In my second dream I was at Cambridge, among a lot of undergraduates. I
+saw a coach drive up with six horses. Three undergraduates got out of
+the coach. I asked them why they had so many horses, and they said,
+"Because of the luggage." I then said, "The luggage is much more than
+the undergraduates. Can you tell me how to express this in mathematical
+symbols? This is the way: if _x_ is the weight of an undergraduate, then
+_x_ + _x_.n represents the weight of an undergraduate and his luggage
+together." I noticed that this sally was received with evident
+enjoyment.[99]
+
+We may say, then, that the structure of our dreams, equally with the
+fact of their completely illusory character, points to the conclusion
+that during sleep, just as in the moments of illusion in waking life,
+there is a deterioration of our intellectual life. The highest
+intellectual activities answering to the least stable nervous
+connections are impeded, and what of intellect remains corresponds to
+the most deeply organized connections.
+
+In this way, our dream-life touches that childish condition of the
+intelligence which marks the decadence of old age and the encroachments
+of mental disease. The parallelism between dreams and insanity has been
+pointed out by most writers on the subject. Kant observed that the
+madman is a dreamer awake, and more recently Wundt has remarked that,
+when asleep, we "can experience nearly all the phenomena which meet us
+in lunatic asylums." The grotesqueness of the combinations, the lack of
+all judgment as to consistency, fitness, and probability, are common
+characteristics of the short night-dream of the healthy and the long
+day-dream of the insane.[100]
+
+But one great difference marks off the two domains. When dreaming, we
+are still sane, and shall soon prove our sanity. After all, the dream of
+the sleeper is corrected, if not so rapidly as the illusion of the
+healthy waker. As soon as the familiar stimuli of light and sound set
+the peripheral sense-organs in activity, and call back the nervous
+system to its complete round of healthy action, the illusion disappears,
+and we smile at our alarms and agonies, saying, "Behold, it was a
+dream!"
+
+On the practical side, the illusions and hallucinations of sleep must be
+regarded as comparatively harmless. The sleeper, in healthy conditions
+of sleep, ceases to be an agent, and the illusions which enthral his
+brain have no evil practical consequences. They may, no doubt, as we
+shall see in a future chapter, occasionally lead to a subsequent
+confusion of fiction and reality in waking recollection. But with the
+exception of this, their worst effect is probably the lingering sense of
+discomfort which a "nasty dream" sometimes leaves with us, though this
+may be balanced by the reverberations of happy dream-emotions which
+sometimes follow us through the day. And however this be, it is plain
+that any disadvantages thus arising are more than made good by the
+consideration that our liability to these nocturnal illusions is
+connected with the need of that periodic recuperation of the higher
+nervous structures which is a prime condition of a vigorous intellectual
+activity, and so of a triumph over illusion during waking life.
+
+For these reasons dreams may properly be classed with the illusions of
+normal or healthy life, rather than with those of disease. They
+certainly lie nearer this region than the very similar illusions of the
+somnambulist, which with respect to their origin appear to be more
+distinctly connected with a pathological condition of the nervous
+system, and which, with respect to their practical consequences may
+easily prove so disastrous.
+
+
+_After-Dreams._
+
+In concluding this account of dreams, I would call attention to the
+importance of the transition states between sleeping and waking, in
+relation to the production of sense-illusion. And this point may be
+touched on here all the more appropriately, since it helps to bring out
+the close relation between waking and sleeping illusion. The mind does
+not pass suddenly and at a bound from the condition of dream-fancy to
+that of waking perception. I have already had occasion to touch on the
+"hypnagogic state," that condition of somnolence or "sleepiness" in
+which external impressions cease to act, the internal attention is
+relaxed, and the weird imagery of sleep begins to unfold itself. And
+just as there is this anticipation of dream-hallucination in the
+presomnial condition, so there is the survival of it in the postsomnial
+condition. As I have observed, dreams sometimes leave behind them, for
+an appreciable interval after waking, a vivid after-impression, and in
+some cases even the semblance of a sense-perception.
+
+If one reflects how many ghosts and other miraculous apparitions are
+seen at night, and when the mind is in a more or less somnolent
+condition, the idea is forcibly suggested that a good proportion of
+these visions are the _debris_ of dreams. In some cases, indeed, as that
+of Spinoza, already referred to, the hallucination (in Spinoza's case
+that of "a scurvy black Brazilian") is recognized by the subject himself
+as a dream-image.[101] I am indebted to Mr. W.H. Pollock for a fact
+which curiously illustrates the position here adopted. A lady was
+staying at a country house. During the night and immediately on waking
+up she had an apparition of a strange-looking man in mediaeval costume,
+a figure by no means agreeable, and which seemed altogether unfamiliar
+to her. The next morning, on rising, she recognized the original of her
+hallucinatory image in a portrait hanging on the wall of her bedroom,
+which must have impressed itself on her brain before the occurrence of
+the apparition, though she had not attended to it. Oddly enough, she now
+learnt for the first time that the house at which she was staying had
+the reputation of being haunted, and by the very same somewhat
+repulsive-looking mediaeval personage that had troubled her
+inter-somnolent moments. The case seems to me to be typical with respect
+to the genesis of ghosts, and of the reputation of haunted houses.
+
+       *       *       *       *       *
+
+NOTE.
+
+THE HYPNOTIC CONDITION.
+
+
+I have not in this chapter discussed the relation of dreaming to
+hypnotism, or the state of artificially produced quasi-sleep, because
+the nature of this last is still but very imperfectly understood. In
+this condition, which is induced in a number of ways by keeping the
+attention fixed on some non-exciting object, and by weak continuous and
+monotonous stimulation, as stroking the skin, the patient can be made to
+act conformably to the verbal or other suggestion of the operator, or to
+the bodily position which he is made to assume. Thus, for example, if a
+glass containing ink is given to him, with the command to drink, he
+proceeds to drink. If his hands are folded, he proceeds to act as if he
+were in church, and so on.
+
+Braid, the writer who did so much to get at the facts of hypnotism, and
+Dr. Carpenter who has helped to make known Braid's careful researches,
+regard the actions of the hypnotized subject as analogous to ideomotor
+movements; that is to say, the movements due to the tendency of an idea
+to act itself out apart from volition. On the other hand, one of the
+latest inquirers into the subject, Professor Heidenhain, of Breslau,
+appears to regard these actions as the outcome of "unconscious
+perceptions" (_Animal Magnetism_, English translation, p. 43, etc.).
+
+In the absence of certain knowledge, it seems allowable to argue from
+the analogy of natural sleep that the actions of the hypnotized patient
+are accompanied with the lower forms of consciousness, including
+sensation and perception, and that they involve dream-like
+hallucinations respecting the external circumstances of the moment.
+Regarding them in this light, the points of resemblance between
+hypnotism and dreaming are numerous and striking. Thus, Dr. Heidenhain
+tells us that the threshold or liminal value of stimulation is lowered
+just as in ordinary sleep sense-activity as a whole is lowered.
+According to Professor Weinhold, the hypnotic condition begins in a
+gradual loss of taste, touch, and the sense of temperature; then sight
+is gradually impaired, while hearing remains throughout the least
+interfered with.[102] In this way, the mind of the patient is largely
+cut off from the external world, as in sleep, and the power of
+orientation is lost. Moreover, there are all the conditions present,
+both positive and negative, for the hallucinatory transformation of
+mental images into percepts just as in natural sleep. Thus, the higher
+centres connected with the operations of reflection and reasoning are
+thrown _hors de combat_ or, as Dr. Heidenhain has it, "inhibited."
+
+The condition of hypnotism is marked off from that of natural sleep,
+first of all, by the fact that the accompanying hallucinations are
+wholly due to external suggestion (including the effects of bodily
+posture). Dreams may, as we have seen, be very faintly modified by
+external influences, but during sleep there is nothing answering to the
+perfect control which the operator exercises over the hypnotized
+subject. The largest quantity of our "dream-stuff" comes, as we have
+seen, from within and not from without the organism. And this fact
+accounts for the chief characteristic difference between the natural and
+the hypnotic dream. The former is complex, consisting of crowds of
+images, and continually changing: the latter is simple, limited, and
+persistent. As Braid remarks, the peculiarity of hypnotism is that the
+attention is concentrated on a remarkably narrow field of mental images
+and ideas. So long as a particular bodily posture is assumed, so long
+does the corresponding illusion endure. One result of this, in
+connection with that impairing of sensibility already referred to, is
+the scope for a curious overriding of sense-impressions by the dominant
+illusory percept, a process that we have seen illustrated in the active
+sense-illusions of waking life. Thus, if salt water is tasted and the
+patient is _told_ that it is beer, he complains that it is sour.
+
+In being thus in a certain rapport, though so limited and unintelligent
+a rapport, with the external world, the mind of the hypnotized patient
+would appear to be nearer the condition of waking illusion than is the
+mind of the dreamer. It must be remembered, however, and this is the
+second point of difference between dreaming and hypnotism, that the
+hypnotized subject tends _to act out_ his hallucinations. His
+quasi-percepts are wont to transform themselves into actions with a
+degree of force of which we see no traces in ordinary sleep. Why there
+should be this greater activity of the motor organs in the one condition
+than in the other, seems to be a point as yet unexplained. All
+sense-impressions and percepts are doubtless accompanied by some degree
+of impulse to movement, though, for some reason or another, in natural
+and healthy sleep these impulses are restricted to the stage of faint
+nascent stirrings of motor activity which hardly betray themselves
+externally. This difference, involving a great difference in the
+possible practical consequences of the two conditions of natural and
+hypnotic sleep, clearly serves to bring the latter condition nearer to
+that of insanity than the former condition is brought. A strong
+susceptibility to the hypnotic influence, such as Dr. Heidenhain
+describes, might, indeed, easily prove a very serious want of
+"adaptation of internal to external relations," whereas a tendency to
+dreaming would hardly prove a maladaptation at all.
+
+
+
+
+CHAPTER VIII.
+
+ILLUSIONS OF INTROSPECTION.
+
+
+We have now, perhaps, sufficiently reviewed sense-illusions, both of
+waking life and of sleep. And having roughly classified them according
+to their structure and origin, we are ready to go forwards and inquire
+whether the theory thus reached can be applied to other forms of
+illusory error. And here we are compelled to inquire at the outset if
+anything analogous to sense-illusion is to be found in that other great
+region of presentative cognition usually marked off from external
+perception as internal perception, self-reflection, or introspection.
+
+
+_Illusions of Introspection defined._
+
+This inquiry naturally sets out with the question: What is meant by
+introspection? This cannot be better defined, perhaps, than by saying
+that it is the mind's immediate reflective cognition of its own states
+as such.
+
+In one sense, of course, everything we know may be called a mental
+state, actual or imagined. Thus, a sense-impression is known, exactly
+like any other feeling of the mind, as a mental phenomenon or mental
+modification. Yet we do not usually speak of introspectively
+recognizing a sensation. Our sense-impressions are marked off from all
+other feelings by having an objective character, that is to say, an
+immediate relation to the external world, so that in attending to one of
+them our minds pass away from themselves in what Professor Bain calls
+the attitude of objective regard. Introspection is confined to feelings
+which want this intimate connection with the external region, and
+includes sensation only so far as it is viewed apart from external
+objects and on its mental side as a feeling, a process which is next to
+impossible where the sensation has little emotional colour, as in the
+case of an ordinary sensation of sight or of articulate sound.
+
+This being so, errors of introspection, supposing such to be found, will
+in the main be sufficiently distinguished from those of perception. Even
+an hallucination of sense, whether setting out from a subjective
+sensation or not, always contains the semblance of a sense-impression,
+and so would not be correctly classed with errors of introspection.
+
+Just as introspection must be marked off from perception, so must it be
+distinguished from memory. It may be contended that, strictly speaking,
+all introspection is retrospection, since even in attending to a present
+feeling the mind is reflectively representing to itself the immediately
+preceding momentary experience of that feeling. Yet the adoption of this
+view does not hinder us from drawing a broad distinction between acts of
+introspection and acts of memory. Introspection must be regarded as
+confined to the knowledge of immediately antecedent mental states with
+reference to which, no error of memory can be supposed to arise.
+
+It follows from this that an illusion of introspection could only be
+found in connection with the apprehension of present or immediately
+antecedent mental states. On the other hand, any illusions connected
+with the consciousness of personal continuity and identity would fall
+rather under the class of mnemonic than that of introspective error.
+
+Once more, introspection must be carefully distinguished from what I
+have called belief. Some of our beliefs may be found to grow out of and
+be compounded of a number of introspections. Thus, my conception of my
+own character, or my psychological conception of mind as a whole, may be
+seen to arise by a combination of the results of a number of acts of
+introspection. Yet, supposing this to be so, we must still distinguish
+between the single presentative act of introspection and the
+representative belief growing out of it.
+
+It follows from this that, though an error of the latter sort might
+conceivably have its origin in one of the former; though, for example, a
+man's illusory opinion of himself might be found to involve errors of
+introspection, yet the two kinds of illusion would be sufficiently
+unlike. The latter would be a simple presentative error, the former a
+compound representative error.
+
+Finally, in order to complete this preliminary demarcation of our
+subject-matter, it is necessary to distinguish between an introspection
+(apparent or real) of a feeling or idea, and a process of inference
+based on this feeling. The term introspective knowledge must, it is
+plain, be confined to what is or appears to be in the mind at the moment
+of inspection.
+
+By observing this distinction, we are in a position to mark off an
+_illusion_ of introspection from a _fallacy_ of introspection. The
+former differs from the latter in the absence of anything like a
+conscious process of inference. Thus, if we suppose that the derivation
+by Descartes of the fact of the existence of God from his possession of
+the idea to be erroneous, such a consciously performed act of reasoning
+would constitute a fallacy rather than an illusion of introspection.
+
+We may, then, roughly define an illusion of introspection as an error
+involved in the apprehension of the contents of the mind at any moment.
+If we mistake the quality or degree of a feeling or the structure of a
+complex mass of feeling, or if we confuse what is actually present to
+the mind with some inference based on this, we may be said to fall into
+an illusion of introspection.
+
+But here the question will certainly be raised: How can we conceive the
+mind erring as to the nature of its present contents; and what is to
+determine, if not my immediate act of introspection, what is present in
+my mind at any moment? Indeed, to raise the possibility of error in
+introspection seems to do away with the certainty of presentative
+knowledge.
+
+If, however, the reader will recall what was said in an earlier chapter
+about the possibility of error in recognizing the quality of a
+sense-impression, he will be prepared for a similar possibility here.
+What we are accustomed to call a purely presentative cognition is, in
+truth, partly representative. A feeling as pure feeling is not known; it
+is only known when it is distinguished, as to quality or degree, and so
+classed or brought under some representation of a kind or description of
+feeling, as acute, painful, and so on. The accurate recognition of an
+impression of colour depends, as we have seen, on this process of
+classing being correctly performed. Similarly, the recognition of
+internal feelings implies the presence of the appropriate or
+corresponding class-representation. Accordingly, if it is possible for a
+wrong representation to get substituted for the right one, there seems
+to be an opening for error.
+
+Any error that would thus arise can, of course, only be determined as
+such in relation to some other act of introspection of the same mind. In
+matters of internal perception other minds cannot directly assist us in
+correcting error as they can in the case of external perception, though,
+as we shall see by-and-by, they may do so indirectly. The standard of
+reality directly applicable to introspective cognition is plainly what
+the individual mind recognizes at its best moments, when the processes
+of attention and classifying are accurately performed, and the
+representation may be regarded with certainty as answering to the
+feeling. In other words, in the sphere of internal, as in that of
+external experience, the criterion of reality is the average and
+perfect, as distinguished from the particular variable and imperfect act
+of cognition.
+
+We see, then, that error in the process of introspection is at least
+conceivable. And now let us examine this process a little further, in
+order to find out what probabilities of error attach to it.
+
+To begin with, then, an act of introspection, to be complete, clearly
+involves the apprehension of an internal feeling or idea as something
+mental and marked off from the region of external experience. This
+distinct recognition of internal states of mind as such, in opposition
+to external impressions, is by no means easy, but presupposes a certain
+degree of intellectual culture, and a measure of the power of abstract
+attention.
+
+
+_Confusion of Internal and External Experience._
+
+Accordingly, we find that where this is wanting there is a manifest
+disposition to translate internal feelings into terms of external
+impressions. In this way there may arise a slight amount of habitual and
+approximately constant error. Not that the process approaches to one of
+hallucination; but only that the internal feelings are intuited as
+having a cause or origin analogous to that of sense-impressions. Thus to
+the uncultivated mind a sudden thought seems like an audible
+announcement from without. The superstitious man talks of being led by
+some good or evil spirit when new ideas arise in his mind or new
+resolutions shape themselves. To the simple intelligence of the boor
+every thought presents itself as an analogue of an audible voice, and he
+commonly describes his rough musings as saying this and that to himself.
+And this, mode of viewing the matter is reflected even, in the language
+of cultivated persons. Thus we say, "The idea struck me," or "was borne
+in on me," "I was forced to do so and so," and so on, and in this
+manner we tend to assimilate internal to external mental phenomena.
+
+Much the same thing shows itself in our customary modes of describing
+our internal feelings of pleasure and pain. When a man in a state of
+mental depression speaks of having "a load" on his mind it is evident
+that he is interpreting a mental by help of an analogy to a bodily
+feeling. Similarly, when we talk of the mind being torn by doubt or worn
+by anxiety. It would seem as though we tended mechanically to translate
+mental pleasures and pains into the language of bodily sensations.
+
+The explanation of this deeply rooted tendency to a slightly illusory
+view of our mental states is, I think, an easy one. For one thing, it
+follows from the relation of the mental image to the sense-impression
+that we should tend to assimilate the former to the latter as to its
+nature and origin. This would account for the common habit of regarding
+thoughts, which are of course accompanied by representatives of their
+verbal symbols, as internal voices, a habit which is probably especially
+characteristic of the child and the uncivilized man, as we have found it
+to be characteristic of the insane.
+
+Another reason, however, must be sought for the habit of assimilating
+internal feelings to external sensations. If language has been evolved
+as an incident of social life, at once one of its effects and its
+causes, it would seem to follow that it must have first shaped Itself to
+the needs of expressing these common objective experiences which we
+receive by way of our senses. Our habitual modes of thought, limited as
+they are by language, retain traces of this origin. We cannot conceive
+any mental process except by some vague analogy to a physical process.
+In other words, we can even now only think with perfect clearness when
+we are concerned with some object of common cognition. Thus, the sphere
+of external sensation and of physical agencies furnishes us with the one
+type of thinkable thing or object of thought, and we habitually view
+subjective mental states as analogues of these.
+
+Still, it may be said that these slight nascent errors are hardly worth
+naming, and the question would still appear to recur whether there are
+other fully developed errors deserving to rank along with illusions of
+sense. Do we, it may be asked, ever actually mistake the quality,
+degree, or structure of our internal feelings in the manner hinted
+above, and if so, what is the range of such error? In order to
+appreciate the risks of such error, let us compare the process of
+self-observation with that of external perception with respect to the
+difficulties in the way of accurate presentative knowledge.
+
+
+_Misreading of Internal Feelings._
+
+First of all, it is noteworthy that a state of consciousness at any one
+moment is an exceedingly complex thing. It is made up of a mass of
+feelings and active impulses which often combine and blend in a most
+inextricable way. External sensations come in groups, too, but as a rule
+they do not fuse in apparently simple wholes as our internal feelings
+often do. The very possibility of perception depends on a clear
+discrimination of sense-elements, for example, the several sensations
+of colour obtained by the stimulation of different parts of the
+retina.[103] But no such clearly defined mosaic of feelings presents
+itself in the internal region: one element overlaps and partly loses
+itself in another, and subjective analysis is often an exceedingly
+difficult matter. Our consciousness is thus a closely woven texture in
+which the mental eye often fails to trace the several threads or
+strands. Moreover, there is the fact that many of these ingredients are
+exceedingly shadowy, belonging to that obscure region of
+sub-consciousness which it is so hard to penetrate with the light of
+discriminative attention. This remark applies with particular force to
+that mass of organic feelings which constitutes what is known as
+coenaesthesis; or vital sense.
+
+While, to speak figuratively, the minute anatomy of consciousness is
+thus difficult with respect to longitudinal sections of the mental
+column, it is no less difficult with respect to transverse sections.
+Under ordinary circumstances, external impressions persist so that they
+can be transfixed by a deliberate act of attention, and objects rarely
+flit over the external scene so rapidly as to allow us no time for a
+careful recognition of the impression. Not so in the case of the
+internal region of mind. The composite states of consciousness just
+described never remain perfectly uniform for the shortest conceivable
+duration. They change continually, just as the contents of the
+kaleidoscope vary with every shake of the instrument. Thus, one shade
+of feeling runs into another in such a way that it is often impossible
+to detect its exact quality; and even when the character of the feeling
+does not change, its intensity is undergoing alterations so that an
+accurate observation of its quantity is impracticable. Also, in this
+unstable shifting internal scene features may appear for a duration too
+short to allow of close recognition. In this way it happens that we
+cannot sharply divide the feeling of the moment from its antecedents and
+its consequents.
+
+If, now, we take these facts in connection with what has been said above
+respecting the nature of the process of introspection, the probability
+of error will be made sufficiently clear. To transfix any particular
+feeling of the moment, to selectively attend to it, and to bring it
+under the proper representation, is an operation that requires time, a
+time which, though short, is longer than the fugitive character of so
+much of our internal mental life allows. From all of which it would
+appear to follow that it must be very easy to overlook, confuse, and
+transform, both as to quality and as to quantity, the actual ingredients
+of our internal consciousness.
+
+From these sources there spring a number of small errors of
+introspection which, to distinguish them from others to be spoken of
+presently, may be called passive. These would include all errors in
+detecting what is in consciousness due to the intricacies of the
+phenomena, and not aided by any strong basis. For example, a mental
+state may fail to disclose its component parts to introspective
+attention. Thus, a motive may enter into our action which is so
+entangled with other feelings as to escape our notice. The fainter the
+feeling the greater the difficulty of detaching it and inspecting it in
+isolation. Again, an error of introspection may have its ground in the
+fugitive character of a feeling. If, for example, a man is asked whether
+a rapid action was a voluntary one, he may in retrospection easily
+imagine that it was not so, when as a matter of fact the action was
+preceded by a momentary volition. When a person exclaims, "I did a thing
+inadvertently or mechanically," it often means that he did not note the
+motive underlying the action. Such transitory feelings which cannot at
+the moment be seized by an act of attention are pretty certain to
+disappear at once, leaving not even a temporary trace in consciousness.
+
+We will now pass to the consideration of other illusions of
+introspection more analogous to what I have called the active illusions
+of perception. In our examination of these we found that a pure
+representation may under certain circumstances simulate the appearance
+of a presentation, that a mental image may approximate to a
+sense-impression. In the case of the internal feelings this liability
+shows itself in a still more striking form.
+
+The higher feelings or emotions are distinguished from the simple
+sense-feelings in being largely representative. Thus, a feeling of
+contentment at any moment, though no doubt conditioned by the bodily
+state and the character of the organic sensations or coenaesthesis,
+commonly depends for the most part on intellectual representations of
+external circumstances or relations, and may be called an ideal
+foretaste of actual satisfactions, such as the pleasures of success, of
+companionship, and so on. This being so, it is easy for imagination to
+call up a semblance of these higher feelings. Since they depend largely
+on representation, a mere act of representation may suffice to excite a
+degree of the feeling hardly distinguishable from the actual one. Thus,
+to imagine myself as contented is really to see myself at the moment as
+actually contented. Again, the actor, though, as we shall see by-and-by,
+he does not feel all that the spectator is apt to attribute to him,
+tends, when vividly representing to himself a particular shade of
+feeling, to regard himself as actually feeling in this way. Thus, it is
+said of Garrick, that when acting Richard III., he felt himself for the
+moment to be a villain.
+
+We should expect from all this that in the act of introspection the mind
+is apt, within certain limits, to find what it is prepared to find. And
+since there is in these acts often a distinct wish to detect some
+particular feeling, we can see how easy it must be for a man through
+bias and a wrong focussing of the attention to deceive himself up to a
+certain point with respect to the actual contents of his mind.
+
+Let us examine one of these active illusions a little more fully. It
+would at first sight seem to be a perfectly simple thing to determine at
+any given moment whether we are enjoying ourselves, whether our
+emotional condition rises above the pleasure-threshold or point of
+indifference and takes on a positive hue of the agreeable or
+pleasurable. Yet there is good reason for supposing that people not
+unfrequently deceive themselves on this matter. It is, perhaps, hardly
+an exaggeration to say that most of us are capable of imagining that we
+are having enjoyment when we conform to the temporary fashion of social
+amusement. It has been cynically observed that people go into society
+less in order to be happy than to seem so, and one may add that in this
+semblance of enjoyment they may, provided they are not _blase_, deceive
+themselves as well as others. The expectation of enjoyment, the
+knowledge that the occasion is intended to bring about this result, the
+recognition of the external signs of enjoyment in others--all this may
+serve to blind a man in the earlier stages of social amusement to his
+actual mental condition.
+
+If we look closely into this variety of illusion, we shall see that it
+is very similar in its structure and origin to that kind of erroneous
+perception which arises from inattention to the actual impression of the
+moment under the influence of a strong expectation of something
+different. The representation of ourselves as entertained dislodges from
+our internal field of vision our actual condition, relegating this to
+the region of obscure consciousness. Could we for a moment get rid of
+this representation and look at the real feelings of the time, we should
+become aware of our error; and it is possible that the process of
+becoming _blase_ involves a waking up to a good deal of illusion of the
+kind.
+
+Just as we can thus deceive ourselves within certain limits as to our
+emotional condition, so we can mistake the real nature of our
+intellectual condition. Thus, when an idea is particularly grateful to
+our minds, we may easily imagine that we believe it, when in point of
+fact all the time there is a sub-conscious process of criticism going
+on, which if we attended to it for a moment would amount to a distinct
+act of disbelief. Some persons appear to be capable of going on
+habitually practising this petty deceit on themselves, that is to say,
+imagining they believe what in fact they are strongly inclined to doubt.
+Indeed, this remark applies to all the grateful illusions respecting
+ourselves and others, which will have to be discussed by-and-by. The
+impulse to hold to the illusion in spite of critical reflection,
+involves the further introspective illusion of taking a state of doubt
+for one of assurance. Thus, the weak, flattered man or woman manages to
+keep up a sort of fictitious belief in the truth of the words which are
+so pleasant to the ear.
+
+It is plain that the external conditions of life impose on the
+individual certain habits of feeling which often conflict with his
+personal propensities. As a member of society he has a powerful motive
+to attribute certain feelings to himself, and this motive acts as a bias
+in disturbing his vision of what is actually in his mind. While this
+holds good of lighter matters, as that of enjoyment just referred to, it
+applies still more to graver matters. Thus, for example, a man may
+easily persuade himself that he feels a proper sentiment of indignation
+against a perpetrator of some mean or cruel act, when as a matter of
+fact his feeling is much more one of compassion for the previously liked
+offender. In this way we impose on ourselves, disguising our real
+sentiments by a thin veil of make-believe.
+
+So far I have spoken of an illusion of introspection as analogous to
+the slight misapprehensions of sense-impression which were touched on in
+connection with illusions of sense (Chapter III.). It is to be observed,
+however, that the confusing of elements of consciousness, which is so
+prominent a factor in introspective illusion, involves a species of
+error closely analogous to a complete illusion of perception, that is to
+say, one which involves a misinterpretation of a sense-impression.
+
+This variety of illusion is illustrated in the case in which a present
+feeling or thought is confounded with some inference based on it. For
+example, a present thought may, through forgetfulness, be regarded as a
+new discovery. Its originality appears to be immediately made known in
+the very freshness which characterizes it. Every author probably has
+undergone the experience of finding that ideas which started up to his
+mind as fresh creations, were unconscious reminiscences of his own or of
+somebody else's ideas.
+
+In the case of present emotional states this liability to confuse the
+present and the past is far greater. Here there is something hardly
+distinguishable from an active illusion of sense-perception. In this
+condition of mind a man often says that he has an "intuition" of
+something supposed to be immediately given in the feeling itself. For
+instance, one whose mind is thrilled by the pulsation of a new joy
+exclaims, "This is the happiest moment of my life," and the assurance
+seems to be contained in the very intensity of the feeling itself. Of
+course, cool reflection will tell him that what he affirms is merely a
+belief, the accuracy of which presupposes processes of recollection and
+judgment, but to the man's mind at the moment the supremacy of this
+particular joy is immediately intuited. And so with the assurance that
+the present feeling, for example of love, is undying, that it is equal
+to the most severe trials, and so on. A man is said to _feel_ at the
+moment that it is so, though as the facts believed have reference to
+absent circumstances and events, it is plain that the knowledge is by no
+means intuitive.
+
+At such times our minds are in a state of pure feeling: intellectual
+discrimination and comparison are no longer possible. In this way our
+emotions in the moments of their greatest intensity carry away our
+intellects with them, confusing the region of pure imagination with that
+of truth and certainty, and even the narrow domain of the present with
+the vast domain of the past and future. In this condition differences of
+present and future may be said to disappear and the energy of the
+emotion to constitute an immediate assurance of its existence
+absolutely.[104]
+
+The great region for the illustration of these active illusions is that
+of the moral and religious life. With respect to our real motives, our
+dominant aspirations, and our highest emotional experiences, we are
+greatly liable to deceive ourselves. The moralist and the theologian
+have clearly recognized the possibilities of self-deception in matters
+of feeling and impulse. To them it is no mystery that the human heart
+should mistake the fictitious for the real, the momentary and evanescent
+for the abiding. And they have recognized, too, the double bias in these
+errors, namely, the powerful disposition to exaggerate the intensity and
+persistence of a present feeling on the one hand, and on the other hand
+to take a mere wish to feel in a particular way for the actual
+possession of the feeling.
+
+
+_Philosophic Illusions._
+
+The opinion of theologians respecting the nature of moral introspection
+presents a singular contrast to that entertained by some philosophers as
+to the nature of self-consciousness. It is supposed by many of these
+that in interrogating their internal consciousness they are lifted above
+all risk of error. The "deliverance of consciousness" is to them
+something bearing the seal of a supreme authority, and must not be
+called in question. And so they make an appeal to individual
+consciousness a final resort in all matters of philosophical dispute.
+
+Now, on the face of it, it does not seem probable that this operation
+should have an immunity from all liability to error. For the matters
+respecting which we are directed to introspect ourselves, are the most
+subtle and complex things of our intellectual and emotional life. And
+some of these philosophers even go so far as to affirm that the plain
+man is quite equal to the niceties of this process.
+
+It has been brought as a charge against some of these same philosophers
+that they have based certain of their doctrines on errors of
+introspection. This charge must, of course, be received with some sort
+of suspicion here, since it has been brought forward by avowed disciples
+of an opposite philosophic school. Nevertheless, as there is from our
+present disinterested and purely scientific point of view a presumption
+that philosophers like other men are fallible, and since it is certain
+that philosophical introspection does not materially differ from other
+kinds, it seems permissible just to glance at some of these alleged
+illusions in relation to other and more vulgar forms. Further reference
+to them will be made at the end of our study.
+
+These so-called philosophical illusions will be found, like the vulgar
+ones just spoken of, to illustrate the distinction drawn between passive
+and active illusions. That is to say, the alleged misreading of
+individual consciousness would result now from a confusion of distinct
+elements, including wrong suggestion, due to the intricacies of the
+phenomena, now from a powerful predisposition to read something into the
+phenomena.
+
+A kind of illusion in which the passive element seems most conspicuous
+would be the error into which the interrogator of the individual
+consciousness is said to fall respecting simple unanalyzable states of
+mind. On the face of it, it is not likely that a mere inward glance at
+the tangle of conscious states should suffice to determine what is such
+a perfectly simple mental phenomenon. Accordingly, when a writer
+declares that an act of introspection demonstrates the simple
+unanalyzable character of such a feeling as the sentiment of beauty or
+that of moral approval, the opponent of this view clearly has some show
+of argument for saying that this simplicity may be altogether illusory
+and due to the absence of a perfect act of attention. Similarly, when it
+is said that the idea of space contains no representations of muscular
+sensation, the statement may clearly arise from the want of a
+sufficiently careful kind of introspective analysis.[105]
+
+In most cases of these alleged philosophical errors, however, the active
+and passive factors seem to combine. There are certain intricacies in
+the mental phenomenon itself favouring the chances of error, and there
+are independent predispositions leading the mind to look at the
+phenomenon in a wrong way. This seems to apply to the famous declaration
+of a certain school of thinkers that by an act of introspection we can
+intuit the fact of liberty, that is to say, a power of spontaneous
+determination of action superior to and regulative of the influence of
+motives. It may be plausibly contended that this idea arises partly
+from a mixing up of facts of present consciousness with inferences from
+them, and partly from a natural predisposition of the mind to invest
+itself with this supreme power of absolute origination.[106]
+
+In a similar way, it might be contended that other famous philosophic
+dicta are founded on a process of erroneous introspection of subjective
+mental states. In some cases, indeed, it seems a plausible explanation
+to regard these illusions as mere survivals in attenuated shadowy form
+of grosser popular illusions. But this is not yet the time to enter on
+these, which, moreover, hardly fall perhaps under our definition of an
+illusion of introspection.
+
+
+_Value of the Introspective Method._
+
+In drawing up this rough sketch of the illusions of introspection, I
+have had no practical object in view. I have tried to look at the facts
+as they are apart from any conclusions to be drawn from them. The
+question how far the liability to error in any region of inquiry
+vitiates the whole process is a difficult one; and the question whether
+the illusions to which we are subject in introspection materially affect
+the value of self-knowledge as a whole and consequently of the
+introspective method in psychology, as many affirm, is too subtle a one
+to be fully treated now. All that I shall attempt here is to show that
+it does not do this any more than the risk of sense-illusion can be said
+materially to affect the value of external observation.
+
+It is to be noted first of all that the errors of introspection are much
+more limited than those of sense-perception. They broadly answer to the
+slight errors connected with the discrimination and recognition of the
+sense-impression. There is nothing answering to a complete hallucination
+in the sphere of the inner mental life. It follows, too, from what has
+been said above, that the amount of active error in introspection is
+insignificant, since the representation of a feeling or belief is so
+very similar to the actual experience of it.
+
+In brief, the errors of introspection, though numerous, are all too
+slight to render the process of introspection as a whole unsound and
+untrustworthy. Though, as we have seen, it involves, strictly speaking,
+an ingredient of representation, this fact does not do away with the
+broad distinction between presentative and representative cognition.
+Introspection is presentative in the sense that the reality constituting
+the object of cognition, the mind's present feeling, is as directly
+present to the knowing mind as anything can be conceived to be. It may
+be added that the power of introspection is a comparatively new
+acquisition of the human race, and that, as it improves, the amount of
+error connected with its operation may reasonably be expected to become
+infinitesimal.
+
+It is often supposed by those who undervalue the introspective method in
+psychology that there is a special difficulty in the detection of error
+in introspection, owing to the fact that the object of inspection is
+something individual and private, and not open to common scrutiny as the
+object of external perception. Yet, while allowing a certain force to
+this objection I would point out, first of all, that even in
+sense-perception, what the individual mind is immediately certain of is
+its own sensations. The relatively perfect certainty which finally
+attaches to the presentative side of sense-perception is precisely that
+which finally attaches to the results of introspection.
+
+In the second place, it may be said that the contrast between the inner
+and the outer experience is much less than it seems. In many cases our
+emotions are the direct result of a common external cause, and even when
+they are not thus attached to some present external circumstance, we are
+able, it is admitted, by the use of language, roughly to compare our
+individual feelings. And such comparison is continually bringing to
+light the fact that there is a continuity in our mental structure, that
+our highest thoughts and emotions lead us back to our common
+sense-impressions, and that consequently, in spite of all individual
+differences of temperament and mental organization, our inner experience
+is in all its larger features a common experience.
+
+I may add that this supposition of the common nature of our internal
+experience, as a whole, not only underlies the science of psychology,
+but is implied in the very process of detecting and correcting errors of
+introspection. I do not mean that in matters of feeling "authority" is
+to override "private judgment." Our last resort with respect to things
+of the mind is, as I have said, that of careful self-inspection. And the
+progress of psychology and the correction of illusion proceed by means
+of an ever-improving exercise of the introspective faculty. Yet such
+individual inspection can at least be _guided_ by the results of others'
+similar inspection, and should be so guided as soon as a general
+consensus in matters of internal experience is fairly made out. In point
+of fact, the preceding discussion of illusions of introspection has
+plainly rested on the sufficiently verified assumption that the calmest
+and most efficient kind of introspection, in bringing to light what is
+permanent as compared with what is variable in the individual cognition,
+points in the direction of a common body of introspected fact.
+
+
+
+
+CHAPTER IX.
+
+OTHER QUASI-PRESENTATIVE ILLUSIONS: ERRORS OF INSIGHT.
+
+
+Besides the perception of external objects, and the inspection of our
+internal mental states, there are other forms of quasi-presentative
+cognition which need to be touched on here, inasmuch as they are
+sometimes erroneous and illusory.
+
+In the last chapter I alluded to the fact that emotion may arise as the
+immediate accompaniment of a sense-impression. When this is the case
+there is a disposition to read into the external object a quality
+answering to the emotion, just as there is a disposition to ascribe to
+objects qualities of heat and cold answering to the sensations thus
+called. And such a reference of an emotional result to an external
+exciting cause approximates in character to an immediate intuition. The
+cognition of the quality is instantaneous, and quite free from any
+admixture of conscious inference. Accordingly, we have to inquire into
+the illusory forms of such intuition, if such there be.
+
+
+_AEsthetic Intuition._
+
+Conspicuous among these quasi-presentative emotional cognitions is
+aesthetic intuition, that is to say, the perception of an object as
+beautiful. It is not necessary here to raise the question whether there
+is, strictly speaking, any quality in things answering to the sentiment
+of beauty in our minds: this is a philosophical and not a psychological
+question, and turns on the further question, what we mean by object. All
+that we need to assume here is that there are certain aspects of
+external things, certain relations of form, together with a power of
+exciting certain pleasurable ideas in the spectator's mind, which are
+commonly recognized as the cause of the emotion of beauty, and indeed
+regarded as constituting the embodiments of the objective quality,
+beauty. AEsthetic intuition thus clearly implies the immediate assurance
+of the existence of a common source of aesthetic delight, a source bound
+up with an object of common sense-perception. And so we may say that to
+call a thing beautiful is more or less distinctly to recognize it as a
+cause of a present emotion, and to attribute to it a power of raising a
+kindred emotion in other minds.
+
+
+_AEsthetic Illusion._
+
+According to this view of the matter, an illusion of aesthetic intuition
+would arise whenever this power of affecting a number of minds
+pleasurably is wrongly attributed, by an act of "intuition," to an
+object of sense-perception, on the ground of a present personal
+feeling.
+
+Now, this error is by no means unfrequent. Our delight in viewing
+external things, though agreeing up to a certain point, does not agree
+throughout. It is a trite remark that there is a large individual
+factor, a considerable "personal equation," in matters of taste, as in
+other matters. Permanent differences of natural sensibility, of
+experience, of intellectual habits, and so on, make an object
+aesthetically impressive and valuable to one man and not to another. Yet
+these differences tend to be overlooked. The individual mind, filled
+with delight at some spectacle, automatically projects its feeling
+outwards in the shape of a cause of a common sentiment. And the force of
+this impulse cannot be altogether explained as the effect of past
+experiences and of association. It seems to involve, in addition, the
+play of social instincts, the impulse of the individual mind to connect
+itself in sympathy with the collective mind.
+
+Here, as in the other varieties of illusion already treated of, we may
+distinguish between a passive and an active side; only in this case the
+passive side must not be taken as corresponding to any common
+suggestions of the object, as in the case of perception proper. So far
+as an illusion of aesthetic intuition may be considered as passive, it
+must be due to the effect of circumscribed individual associations with
+the object.
+
+All agree that what is called beauty consists, to a considerable extent,
+of a power of awaking pleasant suggestions, but in order that these
+should constitute a ground of aesthetic value, they must be common,
+participated in by all, or at least by an indefinite number. This will
+be the case when the association rests on our common every-day
+experiences, and our common knowledge of things, as in the case of the
+peaceful beauty of an ascending curl of blue smoke in a woody landscape,
+or the awful beauty of a lofty precipice. On the other hand, when the
+experience and recollections, which are the source of the pleasure, are
+restricted and accidental, any attribution of objective worth is
+illusory. Thus, the ascription of beauty to one's native village, to
+one's beloved friends, and so on, in so far as it carries the conviction
+of objective worth, may imply a confusion of the individual with the
+common experience.
+
+The active side of this species of illusions would be illustrated in
+every instance of ascribing beauty to objects which is due, in a
+considerable measure at least, to some pre-existing disposition in the
+mind, whether permanent or temporary. A man brings his peculiar habits
+of thought and feeling to the contemplation of objects, and the aesthetic
+impression produced is coloured by these predispositions. Thus, a person
+of a sad and gloomy cast of mind will be disposed to see a sombre beauty
+where other eyes see nothing of the kind. And then there are all the
+effects of temporary conditions of the imagination and the feelings.
+Thus, the individual mind may be focussed in a certain way through the
+suggestion of another. People not seldom see a thing to be beautiful
+because they are told that it is so. It might not be well to inquire too
+curiously how many of the frequenters of the annual art exhibitions use
+their own eyes in framing their aesthetic judgments. Or the temporary
+predisposition may reside in a purely personal feeling or desire
+uppermost at the time. Our enjoyment of nature or of art is coloured by
+our temporary mood. There are moments of exceptional mental
+exhilaration, when even a commonplace scene will excite an appreciable
+kind of admiration. Or there may be a strong wish to find a thing
+beautiful begotten of another feeling. Thus, a lover desires to find
+beauty in his mistress; or, having found it in her face and form,
+desires to find a harmonious beauty in her mind. In these different ways
+temporary accidents of personal feeling and imagination enter into and
+determine our aesthetic intuition, making it deviate from the common
+standard. This kind of error may even approximate in character to an
+hallucination of sense when there is nothing answering to a common
+source of aesthetic pleasure. Thus, the fond mother, through the very
+force of her affection, will construct a beauty in her child, which for
+others is altogether non-existent.
+
+What applies to the perception of beauty in the narrow sense will apply
+to all other modes of aesthetic intuition, as that of the sublime and the
+ludicrous, and the recognition of the opposite of beauty or the ugly. In
+like manner, it will apply to moral intuition in so far as it is an
+instantaneous recognition of a certain quality in a perceived action
+based on, or at least conjoined with, a particular emotional effect. In
+men's intuitive judgments respecting the right and the wrong, the noble
+and base, the admirable and contemptible, and so on, we may see the same
+kind of illusory universalizing of personal feeling as we have seen in
+their judgments respecting the beautiful. And the sources of the error
+are the same in the two cases. Accidents of experience, giving special
+associations to the actions, will not unfrequently warp the individual
+intuition. Ethical culture, like aesthetic culture, means a continual
+casting aside of early illusory habits of intuition. And further, moral
+intuition illustrates all those effects of feeling which we have briefly
+traced in the case of aesthetic intuition. The perversions of the moral
+intuition under the sway of prejudice are too familiar to need more than
+a bare allusion.
+
+
+_Nature of Insight._
+
+There remains one further mode of cognition which approximates in
+character to presentative knowledge, and is closely related to external
+perception. I refer to the commonly called "intuitive" process by which
+we apprehend the feelings and thoughts of other minds through the
+external signs of movement, vocal sound, etc., which make up expression
+and language. This kind of knowledge, which is not sufficiently marked
+off from external perception on the one side and introspection on the
+other, I venture to call Insight.
+
+I am well aware that this interpretation of the mental states of others
+is commonly described as a process of inference involving a conscious
+reference to our own similar experiences. I willingly grant that it is
+often so. At the same time, it must be perfectly plain that it is not
+always so. It is, indeed, doubtful whether in its first stages in early
+life it is invariably so, for there seem to be good reasons for
+attributing to the infant mind a certain degree of instinctive or
+inherited capability in making out the looks and tones of others.[107]
+And, however this may be, it is certain that with the progress of life a
+good part of this interpretation comes to be automatic or unconscious,
+approximating in character to a sense-perception. To recognize
+contentment in a placid smile is, one would say, hardly less immediate
+and intuitive than to recognize the coolness of a stream.
+
+We must, of course, all allow that the fusion of the presentative and
+the representative element is, speaking generally, more complete in the
+case of sense-perception than in that here considered. In spite of
+Berkeley's masterly account of the _rationale_ of visual perception as
+an interpretation of "visual language" and all that has confirmed it,
+the plain man cannot, at the moment of looking at an object, easily
+bring himself to admit that distance is not directly present to his
+vision. On the other hand, on cool reflection, he will recognize that
+the complacent benevolent sentiment is distinct from the particular
+movements and changes in the eye and other features which express it.
+Yet, while admitting this, I must contend that there is no very hard and
+fast line dividing the two processes, but that the reading of others'
+feelings approximates in character to an act of perception.
+
+An intuitive insight may, then, be defined as that instantaneous,
+automatic, or "unconscious" mode of interpreting another's feeling
+which occurs whenever the feeling is fully expressed, and when its signs
+are sufficiently familiar to us. This definition will include the
+interpretation of thoughts by means of language, though not, of course,
+the belief in an objective fact grounded on a recognition of another's
+belief. On the other hand, it will exclude all the more complex
+interpretations of looks and words which imply conscious comparison,
+reflection, and reasoning. Further, it will exclude a large part of the
+interpretation of actions as motived, since this, though sometimes
+approaching the intuitive form, is for the most part a process of
+conjectural or doubtful inference, and wanting in the immediate
+assurance which belongs to an intuitive reading of a present emotion or
+thought.
+
+From this short account of the process of insight, its relation to
+perception and introspection becomes pretty plain. On the one hand, it
+closely resembles sense-perception, since it proceeds by the
+interpretation of a sense-impression by means of a representative image.
+On the other hand, it differs from sense-perception, and is more closely
+allied to introspection in the fact that, while the process of
+interpretation in the former case is a reconstruction of _external_
+experiences, in the latter case it is a reconstruction of _internal_
+experiences. To intuit another's feeling is clearly to represent to
+ourselves a certain kind of internal experience previously known, in its
+elements at least, by introspection, while these represented experiences
+are distinctly referred to another personality.
+
+And now we see what constitutes the object of insight. This is, in part,
+a common experience, as in the case of sense-perception and aesthetic
+intuition, since to perceive another's feeling is implicitly to cognize
+the external conditions of a common insight. But this is clearly not the
+whole, nor even the main part of objective reality in this act of
+cognition. An intuitive insight differs from a sense-perception in that
+it involves an immediate assurance of the existence of a feeling
+presentatively known, though not to our own minds. The object in insight
+is thus a presentative feeling as in introspection, though not our own,
+but another's. And so it differs from the object in sense-perception in
+so far as this last involves sense-experiences, as muscular and tactual
+feelings, which are not _at the moment_ presentatively known to any
+mind.
+
+
+_Illusions of Insight._
+
+And now we are in a position, perhaps, to define an illusion of insight,
+and to inquire whether there is anything answering to our definition. An
+illusory insight is a quasi-intuition of another's feelings which does
+not answer to the internal reality as presentatively known to the
+subject himself. In spite of the errors of introspection dealt with in
+the last chapter, nobody will doubt that, when it is a question between
+a man's knowing what is at the moment in his own mind and somebody
+else's knowing, logic, as well as politeness, requires us to give
+precedence to the former.
+
+An illusion of insight, like the other varieties of illusion already
+dealt with, may arise either by way of wrong suggestion or by way of a
+warping preconception. Let us look at each of these sources apart.
+
+Our insights, like our perceptions, though intuitive in form, are
+obviously determined by previous experience, association, and habit.
+Hence, on its passive side, an illusion of insight may be described as a
+wrong interpretation of a new or exceptional case. For example, having
+associated the representation of a slight feeling of astonishment with
+uplifted eyebrows, we irresistibly tend to see a face in which this is a
+constant feature as expressing this particular shade of emotion. In this
+way we sometimes fall into grotesque errors as to mental traits. And the
+most practised physiognomist may not unfrequently err by importing the
+results of his special circle of experiences into new and unlike cases.
+
+Much the same thing occurs in language. Our timbre of voice, our
+articulation, and our vocabulary, like our physiognomy, have about them
+something individual, and error often arises from overlooking this, and
+hastily reading common interpretations into exceptional cases. The
+misunderstandings that arise even among the most open and confiding
+friends sufficiently illustrate this liability to error.
+
+Sometimes the error becomes more palpable, as, for example, when we
+visit another country. A foreign language, when heard, provokingly
+suggests all kinds of absurd meanings through analogies to our familiar
+tongue. Thus, the Englishman who visits Germany cannot, for a time, hear
+a lady use the expression, "Mein Mann," without having the amusing
+suggestion that the speaker is wishing to call special attention to the
+fact of her husband's masculinity. And doubtless the German who visits
+us derives a similar kind of amusement from such involuntary
+comparisons.
+
+A fertile source of illusory insight is, of course, conscious deception
+on the part of others. The rules of polite society require us to be
+hypocrites in a small way, and we have occasionally to affect the signs
+of amiability, interest, and amusement, when our actual sentiment is one
+of indifference, weariness, or even positive antipathy. And in this way
+a good deal of petty illusion arises. Although we may be well aware of
+the general untrustworthiness of this society behaviour, such is the
+force of association and habit, that the bland tone and flattering word
+irresistibly excite a momentary feeling of gratification, an effect
+which is made all the more easy by the co-operation of the recipient's
+own wishes, touched on in the last chapter.
+
+Among all varieties of this deception, that of the stage is the most
+complete. The actor is a man who has elaborately trained himself in the
+simulation of certain feelings. And when his acting is of the best
+quality, and the proper bodily attitude, gesture, tone of voice, and so
+on, are hit off, the force of the illusion completely masters us. For
+the moment we lose sight of the theatrical surroundings, and see the
+actor as really carried away by the passion which he so closely
+imitates. Histrionic illusion is as complete as any artistic variety can
+venture to be.[108]
+
+I have said that our insights are limited by our own mental experience,
+and so by introspection. In truth, every interpretation of another's
+look and word is determined ultimately, not by what we have previously
+observed in others, but by what we have personally felt, or at least
+have in a sense made our own by intense sympathy. Hence we may, in
+general, regard an illusion of insight on the active side as a hasty
+projection of our own feelings, thoughts, etc., into other minds.
+
+We habitually approach others with a predisposition to attribute to them
+our own modes of thinking and feeling. And this predisposition will be
+the more powerful, the more desirous we are for sympathy, and for that
+confirmation of our own views which the reflection of another mind
+affords. Thus, when making a new acquaintance, people are in general
+disposed to project too much of themselves into the person who is the
+object of inspection. They intuitively endow him with their own ideas,
+ways of looking at things, prejudices of sentiment, and so on, and
+receive something like a shock when later on they find out how different
+he is from this first hastily formed and largely performed image.
+
+The same thing occurs in the reading of literature, and the appreciation
+of the arts of expression generally. We usually approach an author with
+a predisposition to read our own habits of thought and sentiment into
+his words. It is probably a characteristic defect of a good deal of
+current criticism of remote writers to attribute to them too much of our
+modern conceptions and aims. Similarly, we often import our own special
+feelings into the utterances of the poet and of the musical composer.
+That much of this intuition is illusory, may be seen by a little
+attention to the "intuitions" of different critics. Two readers of
+unlike emotional organization will find incompatible modes of feeling in
+the same poet. And everybody knows how common it is for musical critics
+and amateurs to discover quite dissimilar feelings in the same
+composition.[109]
+
+The effect of this active projection of personal feeling will, of
+course, be seen most strikingly when there is a certain variety of
+feeling actually excited at the time in the observer's mind. A man who
+is in a particularly happy mood tends to reflect his exuberant gladness
+on others. The lover, in the moment of exalted emotion, reads a response
+to all his aspirations in his mistress's eyes. Again, a man will tend to
+project his own present ideas into the minds of others, and so imagine
+that they know what he knows; and this sometimes leads to a comical kind
+of embarrassment, and even to a betrayal of something which it was the
+interest of the person to keep to himself. Once more, in interpreting
+language, we may sometimes catch ourselves mistaking the meaning, owing
+to the presence of a certain idea in the mind at the time. Thus, if I
+have just been thinking of Comte, and overhear a person exclaim, "I'm
+positive," I irresistibly tend, for the moment, to ascribe to him an
+avowal of discipleship to the great positivist.
+
+
+_Poetic Illusion._
+
+The most remarkable example of this projection of feeling is
+undoubtedly illustrated in the poetic interpretation of inanimate
+nature. The personification of tree, mountain, ocean, and so on,
+illustrates, no doubt, the effect of association and external
+suggestion; for there are limits to such personification. But
+resemblance and suggestion commonly bear, in this case, but a small
+proportion to active constructive imagination. One might, perhaps, call
+this kind of projection the hallucination of insight, since there is
+nothing objective corresponding to the interpretative image.
+
+The imaginative and poetic mind is continually on the look out for hints
+of life, consciousness, and emotion in nature. It finds a certain kind
+of satisfaction in this half-illusory, dream-like transformation of
+nature. The deepest ground of this tendency must probably be looked for
+in the primitive ideas of the race, and the transmission by inheritance
+of the effect of its firmly fixed habits of mind. The undisciplined mind
+of early man, incapable of distinguishing the object of perception from
+the product of spontaneous imagination, and taking his own double
+existence as the type of all existence, actually saw the stream, the
+ocean, and the mountain as living beings; and so firmly rooted is this
+way of regarding objects, that even our scientifically trained minds
+find it a relief to relapse occasionally into it.[110]
+
+While there is this general imaginative disposition in the poetic mind
+to endow nature with life and consciousness, there are special
+tendencies to project the individual feelings into objects. Every
+imaginative mind looks for reflections of its own deepest feelings in
+the world about it. The lonely embittered heart, craving for sympathy,
+which he cannot meet with in his fellow-man, finds traces of it in the
+sighing of the trees or the moaning of the sad sea-wave. Our Poet
+Laureate, in his great elegy, has abundantly illustrated this impulse of
+the imagination to reflect its own emotional colouring on to inanimate
+things: for example in the lines--
+
+    "The wild unrest that lives in woe
+  Would dote and pore on yonder cloud
+  That rises upward always higher,
+     And onward drags a labouring breast,
+     And topples round the dreary west,
+  A looming bastion fringed with fire."
+
+So far I have been considering active illusions of insight as arising
+through the play of the impulse of the individual mind to project its
+feelings outwards, or to see their reflections in external things. I
+must now add that active illusion may be due to causes similar to those
+which we have seen to operate in the sphere of illusory perception and
+introspection. That is to say, there may be a disposition, permanent or
+temporary, to ascribe a certain kind of feeling to others in accordance
+with our wishes, fears, and so on.
+
+To give an illustration of the permanent causes, it is well known that a
+conceited man will be disposed to attribute admiration of himself to
+others. On the other hand, a shy, timid person will be prone to read
+into other minds the opposite kind of feeling.
+
+Coming to temporary forces, we find that any expectation to meet with a
+particular kind of mental trait in a new acquaintance will dispose the
+observer hastily and erroneously to attribute corresponding feelings to
+the person. And if this expectation springs out of a present feeling,
+the bias to illusory insight is still more powerful. For example, a
+child that fears its parent's displeasure will be prone to misinterpret
+the parent's words and actions, colouring them according to its fears.
+So an angry man, strongly desirous of making out that a person has
+injured him, will be disposed to see signs of conscious guilt in this
+person's looks or words. Similarly, a lover will read fine thoughts or
+sentiments into the mind of his mistress under the influence of a strong
+wish to admire.
+
+And what applies to the illusory interpretation of others' feelings
+applies to the ascription of feelings to inanimate objects. This is due
+not simply to the impulse to expand one's conscious existence through
+far-reaching resonances of sympathy, but also to a permanent or
+temporary disposition to attribute a certain kind of feeling to an
+object. Thus, the poet personifies nature in part because his emotional
+cravings prompt him to construct the idea of something that can be
+admired or worshipped. Once more, the action of a momentary feeling when
+actually excited is seen in the "mechanical" impulse of a man to
+retaliate when he strikes his foot against an object, as a chair, which
+clearly involves a tendency to attribute an intention to hurt to the
+unoffending body, and the _rationale_ of which odd procedure is pretty
+correctly expressed in the popular phrase: "It relieves the feelings."
+
+It is worth noting, perhaps, that these illusions of insight, like those
+of perception, may involve an inattention to the actual impression of
+the moment. To erroneously attribute a feeling to another through an
+excess of sympathetic eagerness is often to overlook what a perfectly
+dispassionate observer would see, as, for example, the immobility of the
+features or the signs of a deliberate effort to simulate. This
+inattention will, it is obvious, be greatest in the poetic attribution
+of life and personality to natural objects, in so far as this
+approximates to a complete momentary illusion. To see a dark overhanging
+rock as a grim sombre human presence, is for the moment to view it under
+this aspect only, abstracting from its many obvious unlikenesses.
+
+In the same manner, a tendency to read a particular meaning into a word
+may lead to the misapprehension of the word. To give an illustration: I
+was lately reading the fifth volume of G. H. Lewes's _Problems of Life
+and Mind_. In reading the first sentence of one of the sections, I again
+and again fell into the error of taking "The great Lagrange," for "The
+great Language." On glancing back I saw that the section was headed "On
+Language," and I at once recognized the cause of my error in the
+pre-existence in my mind of the representative image of the word
+"language."
+
+In concluding this short account of the errors of insight, I may observe
+that their range is obviously much greater than that of the previously
+considered classes of presentative illusion. This is, indeed, involved
+in what has been said about the nature of the process. Insight, as we
+have seen, though here classed with preservative cognition, occupies a
+kind of border-land between immediate knowledge or intuition and
+inference, shading off from the one to the other. And in the very nature
+of the case the scope for error must be great. Even overlooking human
+reticence, and, what is worse, human hypocrisy, the conditions of an
+accurate reading of others' minds are rarely realized. If, as has been
+remarked by a good authority, one rarely meets, even among intelligent
+people, with a fairly accurate observer of external things, what shall
+be said as to the commonly claimed power of "intuitive insight" into
+other people's thoughts and feelings, as though it were a process above
+suspicion? It is plain, indeed, on a little reflection, that, taking
+into account what is required in the way of large and varied experience
+(personal and social), a habit of careful introspection, as well as a
+habit of subtle discriminative attention to the external signs of mental
+life, and lastly, a freedom from prepossession and bias, only a very few
+can ever hope even to approximate to good readers of character.
+
+And then we have to bear in mind that this large amount of error is apt
+to remain uncorrected. There is not, as in the case of external
+perception, an easy way of verification, by calling in another sense; a
+misapprehension, once formed, is apt to remain, and I need hardly say
+that errors in these matters of mutual comprehension have their palpable
+practical consequences. All social cohesion and co-operation rest on
+this comprehension, and are limited by its degree of perfection. Nay,
+more, all common knowledge itself, in so far as it depends on a mutual
+communication of impressions, ideas, and beliefs, is limited by the
+fact of this great liability to error in what at first seems to be one
+of the most certain kinds of knowledge.
+
+In view of this depressing amount of error, our solace must be found in
+the reflection that this seemingly perfect instrument of intuitive
+insight is, in reality, like that of introspection, in process of being
+fashioned. Mutual comprehension has only become necessary since man
+entered the social state, and this, to judge by the evolutionist's
+measure of time, is not so long ago. A mental structure so complex and
+delicate requires for its development a proportionate degree of
+exercise, and it is not reasonable to look yet for perfect precision of
+action. Nevertheless, we may hope that, with the advance of social
+development, the faculty is continually gaining in precision and
+certainty. And, indeed, this hope is already assured to us in the fact
+that the faculty has begun to criticise itself, to distinguish between
+an erroneous and a true form of its-operation. In fact, all that has
+been here said about illusions of insight has involved the assumption
+that intellectual culture sharpens the power and makes it less liable to
+err.
+
+
+
+
+CHAPTER X.
+
+ILLUSIONS OF MEMORY.
+
+
+Thus far we have been dealing with Presentative Illusions, that is to
+say, with the errors incident to the process of what may roughly be
+called presentative cognition. We have now to pass to the consideration
+of Representative Illusion, or that kind of error which attends
+representative cognition in so far as it is immediate or
+self-sufficient, and not consciously based on other cognition. Of such
+immediate representative cognition, memory forms the most conspicuous
+and most easily recognized variety. Accordingly, I proceed to take up
+the subject of the Illusions of Memory.[111]
+
+The mystery of memory lies in the apparent immediateness of the mind's
+contact with the vanished past. In "looking back" on our life, we seem
+to ourselves for the moment to rise above the limitations of time, to
+undo its work of extinction, seizing again the realities which its
+on-rushing stream had borne far from us. Memory is a kind of
+resurrection of the buried past: as we fix our retrospective glance on
+it, it appears to start anew into life; forms arise within our minds
+which, we feel sure, must faithfully represent the things that were. We
+do not ask for any proof of the fidelity of this dramatic representation
+of our past history by memory. It is seen to be a faithful imitation,
+just because it is felt to be a revival of the past. To seek to make the
+immediate testimony of memory more sure seems absurd, since all our ways
+of describing and illustrating this mental operation assume that in the
+very act of performing it we do recover a part of our seemingly "dead
+selves."
+
+To challenge the veracity of a person's memory is one of the boldest
+things one can do in the way of attacking deep-seated conviction. Memory
+is the peculiar domain of the individual. In going back in recollection
+to the scenes of other years he is drawing on the secret store-house of
+his own consciousness, with which a stranger must not intermeddle. To
+cast doubt on a person's memory is commonly resented as an impertinence,
+hardly less rude than to question his reading of his own present mental
+state. Even if the challenger professedly bases his challenge on the
+testimony of his own memory, the challenged party is hardly likely to
+allow the right of comparing testimonies. He can in most cases boldly
+assert that those who differ from him are lacking in _his_ power of
+recollection. The past, in becoming the past, has, for most people,
+ceased to be a common object of reference; it has become a part of the
+individual's own inner self, and cannot be easily dislodged or shaken.
+
+Yet, although people in general are naturally disposed to be very
+confident about matters of recollection, reflective persons are pretty
+sure to find out, sooner or later, that they occasionally fall into
+errors of memory. It is not the philosopher who first hints at the
+mendacity of memory, but the "plain man" who takes careful note of what
+really happens in the world of his personal experience. Thus, we hear
+persons, quite innocent of speculative doubt, qualifying an assertion
+made on personal recollection by the proviso, "unless my memory has
+played me false." And even less reflective persons, including many who
+pride themselves on their excellent memory, will, when sorely pressed,
+make a grudging admission that they may, after all, be in error. Perhaps
+the weakest degree of such an admission, and one which allows to the
+conceding party a semblance of victory, is illustrated in the "last
+word" of one who has boldly maintained a proposition on the strength of
+individual recollection, but begins to recognize the instability of his
+position: "I either witnessed the occurrence or dreamt it." This is
+sufficient to prove that, with all people's boasting about the
+infallibility of memory, there are many who have a shrewd suspicion that
+some of its asseverations will not bear a very close scrutiny.
+
+
+_Psychology of Memory._
+
+In order to understand the errors of memory, we must proceed, as in the
+case of illusions of perception, by examining a little into the nature
+of the normal or correct process.
+
+An act of recollection is said by the psychologist to be purely
+representative in character, whereas perception is partly
+representative, partly preservative. To recall an object to the mind is
+to reconstruct the percept in the absence of a sense-impression.[112]
+
+An act of memory is obviously distinguished from one of simple
+imagination by the presence of a conscious reference to the past. Every
+recollection is an immediate reapprehension of some past object or
+event. However vague this reference may be, it must be there to
+constitute the process one of recollection.
+
+The every-day usages of language do not at first sight seem to
+consistently observe this distinction. When a boy says, "I remember my
+lesson," he appears to be thinking of the present only, and not
+referring to the past. In truth, however, there is a vague reference to
+the fact of retaining a piece of knowledge through a given interval of
+time.
+
+Again, when a man says, "I recollect your face," this means, "Your face
+seems familiar to me." Here again, though there is no definite reference
+to the past, there is a vague and indefinite one.
+
+It is plain from this definition that recollection is involved in all
+recognition or identification. Merely to be aware that I have seen a
+person before implies a minimum exercise of memory. Yet we may roughly
+distinguish the two actions of perception and recollection in the
+process of recognition. The mere recognition of an object does not
+imply the presence of a distinct representative or mnemonic image. In
+point of fact, in so far as recognition is assimilation, it cannot be
+said to imply a _distinct_ act of memory at all. It is only when
+similarity is perceived amid difference, only when the accompaniments or
+surroundings of the object as previously seen, differencing it from the
+object as now seen, are brought up to the mind that we may be said
+distinctly to recall the past. And our state of mind in recognizing an
+object or person is commonly an alternation between these two acts of
+separating the mnemonic image from the percept and so recalling or
+recollecting the past, and fusing the image and the percept in what is
+specifically marked off as recognition.[113]
+
+Although I have spoken of memory as a reinstatement in representative
+form of external experience, the term must be understood to include
+every revival of a past experience, whether external or internal, which
+is recognized as a revival. In a general way, the recallings of our
+internal feelings take place in close connection with the recollection
+of external circumstances or events, and so they may be regarded as
+largely conditioned by the laws of this second kind of reproduction.
+
+The old conceptions of mind, which regarded every mental phenomenon as a
+manifestation of an occult spiritual substance, naturally led to the
+supposition that an act of recollection involves the continued,
+unbroken existence of the reproductive or mnemonic image in the hidden
+regions of the mind. To recollect is, according to this view, to draw
+the image out of the dark vaults of unconscious mind into the upper
+chamber of illumined consciousness.
+
+Modern psychology recognizes no such pigeonhole apparatus in unconscious
+mind. On the purely psychical side, memory is nothing but an occasional
+reappearance of a past mental experience. And the sole mental conditions
+of this reappearance are to be found in the circumstances of the moment
+of the original experience and in those of the moment of the
+reappearance.
+
+Among these are to be specially noted, first of all, the degree of
+impressiveness of the original experience, that is to say, the amount of
+interest it awakened and of attention it excited. The more impressive
+any experience, the greater the chances of its subsequent revival.
+Moreover, the absence of impressiveness in the original experience may
+be made good either by a repetition of the actual experience or, in the
+case of non-recurring experiences, by the fact of previous mnemonic
+revivals.
+
+In the second place, the pre-existing mental states at the time of
+revival are essential conditions. It is now known that every
+recollection is determined by some link of association, that every
+mnemonic image presents itself in consciousness only when it has been
+preceded by some other mental state, presentative or representative,
+which is related to the image. This relation may be one of contiguity,
+that is to say, the original experiences may have occurred at the same
+time or in close succession; or one of similarity (partial and not
+amounting to identity), as where the sight of one place or person
+recalls that of another place or person. Finally, it is to be observed
+that recollection is often an act, in the full sense of that term,
+involving an effort of voluntary attention at the moment of revival.
+
+Modern physiology has done much towards helping us to understand the
+nervous conditions of memory. The biologist regards memory as a special
+phase of a universal property of organic structure, namely,
+modifiability by the exercise of function, or the survival after any
+particular kind of activity of a disposition to act again in that
+particular way. The revival of a mental impression in the weaker form of
+an image is thus, on its physical side, due in part to this remaining
+functional disposition in the central nervous tracts concerned. And so,
+while on the psychical or subjective side we are unable to find anything
+permanent in memory, on the physical or objective side we do find such a
+permanent substratum.
+
+With respect to the special conditions of mnemonic revival at any time,
+physiology is less explicit. In a general way, it informs us that such a
+reinstatement of the past is determined by the existence of certain
+connections between the nervous structures concerned in the reviving and
+revived mental elements. Thus, it is said that when the sound of a name
+calls up in the mind a visual image of a person seen some time since, it
+is because connections have been formed between particular regions and
+modes of activity of the auditory and the visual centres. And it is
+supposed that the existence of such connections is somehow due to the
+fact that the two regions acted simultaneously in the first instance,
+when the sight of the person was accompanied by the hearing of his name.
+In other words, the centres, as a whole, will tend to act at any future
+moment in the same complex way in which they have acted in past moments.
+
+All this is valuable hypothesis so far as it goes, though it plainly
+leaves much unaccounted for. As to why this reinstatement of a total
+cerebral pulsation in consequence of the re-excitation of a portion of
+the same should be accompanied by the specific mode of consciousness
+which we call recollection of something past, it is perhaps unreasonable
+to ask of physiology any sort of explanation.[114]
+
+Thus far as to the general or essential characteristics of memory on its
+mental and its bodily side. But what we commonly mean by memory is, on
+its psychical side at least, much more than this. We do not say that we
+properly recollect a thing unless we are able to refer it to some more
+or less clearly defined region of the past, and to localize it in the
+succession of experiences making up our mental image of the past. In
+other words, though we may speak of an imperfect kind of recollection
+where this definite reference is wanting, we mean by a perfect form of
+memory something which includes this reference.
+
+Without entering just now upon a full analysis of what this reference to
+a particular region of the past means, I may observe that it takes place
+by help of an habitual retracing of the past, or certain portions of it,
+that is to say, a regressive movement of the imagination along the lines
+of our actual experience. Setting out from the present moment, I can
+move regressively to the preceding state of consciousness, to the
+penultimate, and so on. The fact that each distinct mental state is
+continuous with the preceding and the succeeding, and in a certain sense
+overlaps these, makes any portion of our experience essentially a
+succession of states of consciousness, involving some rudimentary idea
+of time. And thus, whether I anticipate a future event or recall a past
+one, my imagination, setting out from the present moment, constructs a
+sequence of experiences of which the one particularly dwelt on is the
+other term or boundary. And our idea of the position of this last in
+time, like that of an object in space, is one of a relation to our
+present position, and is determined by the length of the sequence of
+experiences thus run over by the imagination.[115] It may be added that
+since the imagination can much more easily follow the actual order of
+experience than conceive it as reversed, the retrospective act of memory
+naturally tends to complete itself by a return movement forwards from
+the remembered event to the present moment.
+
+In practice this detailed retracing of successive moments of mental life
+is confined to very recent experiences. If I try to localize in time a
+remote event, I am content with placing it in relation to a series of
+prominent events or landmarks which serves me as a rough scheme of the
+past. The formation of such a mnemonic framework is largely due to the
+needs of social converse, which proceeds by help of a common standard of
+reference. This standard is supplied by those objective, that is to say,
+commonly experienced regularities of succession which constitute the
+natural and artificial divisions of the years, seasons, months, weeks,
+etc. The habit of recurring to these fixed divisional points of the past
+renders a return of imagination to any one of them more and more easy. A
+man has a definite idea of "a year ago" which the child wants, just
+because he has had so frequently to execute that vague regressive
+movement by which the idea arises. And though, as our actual point in
+time moves forward, the relative position of any given landmark is
+continually changing, the change easily adapts itself to that scheme of
+time-divisions which holds good for any present point.
+
+Few of our recollections of remote events involve a definite reference
+to this system of landmarks. The recollections of early life are, in the
+case of most people, so far as they depend on individual memory, very
+vaguely and imperfectly localized. And many recent experiences which are
+said to be half forgotten, are not referred to any clearly assignable
+position in time. One may say that in average cases definite
+localization characterizes only such supremely interesting personal
+experiences as spontaneously recur again and again to the mind. For the
+rest it is confined to those facts and events of general interest to
+which our social habits lead us repeatedly to go back.[116]
+
+The consciousness of personal identity is said to be bound up with
+memory. That is to say, I am conscious of a continuous permanent self
+under all the varying surface-play of the stream of consciousness, just
+because I can, by an act of recollection, bring together any two
+portions of this stream of experience, and so recognize the unbroken
+continuity of the whole. If this is so, it would seem to follow from the
+very fragmentary character of our recollections that our sense of
+identity is very incomplete. As we shall see presently, there is good
+reason to look upon, this consciousness of continuous personal existence
+as resting only in part on memory, and mainly on our independently
+formed representation of what has happened in the numberless and often
+huge lacunae of the past left by memory.
+
+Having thus a rough idea of the mechanism of memory to guide us, we may
+be able to investigate the illusions incident to the process.
+
+
+_Illusions of Memory._
+
+By an illusion of memory we are to understand a false recollection or a
+wrong reference of an idea to some region of the past. It might,
+perhaps, be roughly described as a wrong interpretation of a special
+kind of mental image, namely, what I have called a mnemonic image.
+
+Mnemonic illusion is thus distinct from mere forgetfulness or imperfect
+memory. To forget or be doubtful about a past event is one thing; to
+seem to ourselves to remember it when we afterwards find that the fact
+was otherwise than we represented it in the apparent act of recollection
+is another thing. Indistinctness of recollection, or the decay of
+memory, is, as we shall soon see, an important co-operant condition of
+mnemonic illusion, but does not constitute it, any more than haziness of
+vision or disease of the visual organ, though highly favourable to
+optical illusion, can be said to constitute it.
+
+We may conveniently proceed in our detailed examination of illusions of
+memory, by distinguishing between three facts which appear to be
+involved in every complete and accurate process of recollection. When I
+distinctly recall an event, I am immediately sure of three things: (1)
+that something did really happen to me; (2) that it happened in the way
+I now think; and (3) that it happened when it appears to have happened.
+I cannot be said to recall a past event unless I feel sure on each of
+these points. Thus, to be able to say that an event happened at a
+particular date, and yet unable to describe how it happened, means that
+I have a very incomplete recollection. The same is true when I can
+recall an event pretty distinctly, but fail to assign it its proper
+date. This being so, it follows that there are three possible openings,
+and only three, by which errors of memory may creep in. And, as a matter
+of fact, each of these openings will be found to let in one class of
+mnemonic illusion. Thus we have (1) false recollections, to which there
+correspond no real events of personal history; (2) others which
+misrepresent the manner of happening of the events; and (3) others which
+falsify the date of the events remembered.
+
+It is obvious, from a mere glance at this threefold classification, that
+illusions of memory closely correspond to visual illusions. Thus, class
+(1) may be likened to the optical illusions known as subjective
+sensations of light, or ocular spectra. Here we can prove that there is
+nothing actually seen in the field of vision, and that the semblance of
+a visible object arises from quite another source than that of ordinary
+external light-stimulation, and by what may be called an accident.
+Similarly, in the case of the first class of mnemonic illusions, we
+shall find that there is nothing actually recollected, but that the
+mnemonic spectra or phantoms of recollected objects can be accounted for
+in quite another way. Such illusions come nearest to hallucinations in
+the region of memory.
+
+Again, class (2) has its visual analogue in those optical illusions
+which depend on effects of haziness and of the action of refracting
+media interposed between the eye and the object; in which cases, though
+there is some real thing corresponding to the perception, this is seen
+in a highly defective, distorted, and misleading form. In like manner,
+we can say that the images of memory often get obscured, distorted, and
+otherwise altered when they have receded into the dim distance, and are
+looked back upon through a long space of intervening mental experience.
+Finally, class (3) has its visual counterpart in erroneous perceptions
+of distance, as when, for example, owing to the clearness of the
+mountain atmosphere and the absence of intervening objects, the side of
+the Jungfrau looks to the inexperienced tourist at Wengernalp hardly
+further than a stone's throw. It will be found that when our memory
+falsifies the date of an event, the error arises much in the same way as
+a visual miscalculation of distance.
+
+This threefold division of illusions of memory is plainly a rather
+superficial one, and not based on distinctions of psychological nature
+or origin. In order to make our treatment of the subject scientific as
+well as popular, it will be necessary to introduce the distinction
+between the passive and the active factor under each head. It will be
+found, I think, without forcing the analogy too far, that here, as in
+the case of the illusions of perception and introspection, error is
+attributable now to misleading suggestion on the part of the mental
+content of the moment, now to a process of incorporating into this
+content a mental image not suggested by it, but existing independently.
+
+If we are to proceed as we did in the case of the illusions of sense,
+and take up the lower stages of error first of all, we shall need to
+begin with the third class of errors, those of localization in time, or
+of what may be called mnemonic perspective. It has been already observed
+that the definite localization of a mnemonic image is only an occasional
+accompaniment of what is loosely called recollection. Hence, error as
+to the position of an event in the past chain of events would seem to
+involve the least degree of violation of the confidence which we are
+wont to repose in memory. After this, we may proceed to the discussion
+of the second class, which I may call distortions of the mnemonic
+picture. And, finally, we may deal with the most signal and palpable
+variety of error of memory, namely, the illusions which I have called
+mnemonic spectra.
+
+
+_Illusions of Perspective: A. Definite Localization._
+
+In order to understand these errors of mnemonic perspective, we shall
+have to inquire more closely than we have yet done into the
+circumstances which customarily determine our idea of the degree of
+propinquity or of remoteness of a past event. And first of all, we will
+take the case of a complete act of recollection when the mind is able to
+travel back along an uninterrupted series of experiences to a definitely
+apprehended point. Here there would seem, at first sight, to be no room
+for error, since this movement of retrospective imagination may be said
+to involve a direct measurement of the distance, just as a sweep of the
+eye over the ground between a spectator and an object affords a direct
+measurement of the intervening space.
+
+Modern science, however, tells us that this mode of measurement is by no
+means the simple and accurate process which it at first seems to be. In
+point of fact, there is something like a constant error in all such
+retrospective measurement. Vierordt has proved experimentally, by making
+a person try to reproduce the varying time-intervals between the
+strokes of the pendulum of a metronome, that when the interval is a very
+small one, we uniformly tend to exaggerate it in retrospection; when a
+large one, to regard it, on the contrary, as less than it actually
+was.[117]
+
+A mere act of reflection will convince any one that when he tries to
+conceive a very small interval, say a quarter of a second, he is likely
+to make it too great. On the other hand, when we try to conceive a year,
+we do not fully grasp the whole extent of the duration. This is proved
+by the fact that merely by spending more time over the attempt, and so
+recalling a larger number of the details of the period, we very
+considerably enlarge our first estimate of the duration. And this leads
+to great discrepancies in the appreciation of the relative magnitudes of
+past sections of time. Thus, as Wundt observes, though in retrospect
+both a month and a year seem too short, the latter is relatively much
+more shortened than the former.[118]
+
+The cause of this constant error in the mode of reproducing durations
+seems to be connected with the very nature of the reproductive act. It
+must be borne in mind that this act is itself, like the experience which
+it represents, a mental process, occupying time, and that consequently
+it may very possibly reflect its time-character on the resulting
+judgment. Thus, since it certainly takes more than a quarter of a second
+to pass in imagination from one impression to another, it may be that we
+tend to confound this duration with that which we try to represent.
+Similarly, the fact that in the act of reproductive imagination we
+under-estimate a longer interval between two impressions, say those of
+the slow beats of a colliery engine, may be accounted for by the
+supposition that the imagination tends to pass from the one impression
+to the succeeding one too rapidly.[119]
+
+The gross misappreciation of duration of long periods of time, while it
+may illustrate the principle just touched on, clearly involves the
+effect of other and more powerful influences. A mere glance at what is
+in our mind when we recall such a period as a month or a year, shows
+that there is no clear concrete representation at all. Time, it has been
+often said, is known only so far as filled with concrete contents or
+conscious experiences, and a perfect imagination of any particular
+period of past time would involve a retracing of all the successive
+experiences which have gone to make up this section of our life. This, I
+need not say, never happens, both because, on the one hand, memory does
+not allow of a complete reproduction of any segment of our experience,
+and because, on the other hand, such an imaginative reproduction, even
+if possible, would clearly occupy as much time as the experience
+itself.[120]
+
+When I call up an image of the year just closing, what really happens is
+a rapid movement of imagination over a series of prominent events, among
+which the succession of seasons probably occupies the foremost place,
+serving, as I have remarked, as a framework for my retrospective
+picture. Each of the events which I thus run over is really a long
+succession of shorter experiences, which, however, I do not separately
+represent to myself. My imaginative reproduction of such a period is
+thus essentially a greatly abbreviated and symbolic mode of
+representation. It by no means corresponds to the visual imagination of
+a large magnitude, say that of the length of sea horizon visible at any
+one moment, which is complete in an instant, and quite independent of a
+successive imagination of its parts or details. It is essentially a very
+fragmentary and defective numerical idea, in which, moreover, the real
+quantitative value of the units is altogether lost sight of.
+
+Now, it seems to follow from this that there is something illusory in
+all our recallings of long periods of the past. It is by no means
+strictly correct to say that memory ever reinstates the past. It is more
+true to say that we see the past in retrospect as greatly foreshortened.
+Yet even this is hardly an accurate account of what takes place, since,
+when we look at an object foreshortened in perspective, we see enough to
+enable us imaginatively to reconstruct the actual size of the object,
+whereas in the case of time-perspective no such reconstruction is even
+indirectly possible.
+
+It is to be added that this constant error in time-reproduction is
+greater in the case of remote periods than of near ones of the same
+length. Thus, the retrospective estimate of a duration far removed from
+the present, say the length of time passed at a particular school, is
+much more superficial and fragmentary than that of a recent
+corresponding period. So that the time-vista of the past is seen to
+answer pretty closely to a visible perspective in which the amount of
+apparent error due to foreshortening increases with the distance.
+
+In practice, however, this defect in the imagination of duration leads
+to no error. Although, as a concrete image answering to some definite
+succession of experiences a year is a gross misrepresentation, as a
+general concept implying a collection of a certain number of similar
+successions of experience it is sufficiently exact. That is to say,
+though we cannot imagine the _absolute_ duration of any such cycle of
+experience, we can, by the simple device of conceiving certain durations
+as multiples of others, perfectly well compare different periods of
+times, and so appreciate their _relative_ magnitudes.
+
+Leaving, then, this constant error in time-appreciation, we will pass to
+the variable and more palpable errors in the retrospective measurement
+of time. Each person's experience will have told him that in estimating
+the distance of a past event by a mere retrospective sense of duration,
+he is liable to extraordinary fluctuations of judgment. Sometimes when
+the clock strikes we are surprised at the rapidity of the hour. At other
+times the timepiece seems rather to have lagged behind its usual pace.
+And what is true of a short interval is still more true of longer
+intervals, as months and years. The understanding of these fluctuations
+will be promoted by our brief glance at the constant errors in
+retrospective time-appreciation.
+
+And here it is necessary to distinguish between the sense of duration
+which we have during any period, and the retrospective sense which
+survives the period, for these do not necessarily agree. The former
+rests mainly on our prospective sense of time, whereas the latter must
+be altogether retrospective.[121]
+
+Our estimate of time as it passes is commonly said to depend on the
+amount of consciousness which we are giving to the fact of its
+transition. Thus, when the mind is unoccupied and suffering from
+_ennui_, we feel time to move sluggishly. On the other hand, interesting
+employment, by diverting the thoughts from time, makes it appear to move
+at a more rapid pace. This fact is shown in the common expressions which
+we employ, such as "to kill time," and the German _Langweile_.
+Similarly, it is said that when we are eagerly anticipating an event, as
+the arrival of a friend, the mere fact of dwelling on the interval makes
+it appear to swell out.[122]
+
+This view is correct in the main, and is seen, indeed, to follow from
+the great psychological principle that what we attend to exists for us
+more, has more reality, and so naturally seems greater than what we do
+not attend to. At the same time, this principle must be supplemented by
+another consideration. Suppose that I am very desirous that time should
+not pass quickly. If, for example, I am enjoying myself or indulging in
+idleness, and know that I have to be off to keep a not very agreeable
+engagement in a quarter of an hour, time will seem to pass too rapidly;
+and this not because my thoughts are diverted from the fact of its
+transition, for, on the contrary, they are reverting to it more than
+they usually do, but because my wish to lengthen the interval leads me
+to represent the unwelcome moment as further off than it actually is, in
+other words, to construct an ideal representation of the period in
+contrast with which the real duration looks miserably short.
+
+Our estimate of duration, when it is over, depends less on this
+circumstance of having attended to its transition than on other
+considerations. Wundt, indeed, seems to think that the feeling
+accompanying the actual flow of time has no effect on the surviving
+subjective appreciation; but this must surely be an error, since our
+mental image of any period is determined by the character of its
+contents. Wundt says that when once a tedious waiting is over, it looks
+short because we instantly forget the feeling of tedium. My
+self-observation, as well as the interrogation of others, has satisfied
+me, on the contrary, that this feeling distinctly colours the
+retrospective appreciation. Thus, when waiting at a railway station for
+a belated train, I am distinctly aware that each quarter of an hour
+looks long, not only as it passes, but when it is over. In fact, I am
+disposed to express my feeling as one of disappointment that only so
+short an interval has passed since I last looked at my watch.
+
+Nevertheless, I am ready to allow that, though a feeling of tedium, or
+the contrary feeling of irritation at the rapidity of time, will linger
+for an appreciable interval and colour the retrospective estimate of
+time, this backward view is chiefly determined by other considerations.
+As Wundt remarks, we have no sense of time's slowness during sleep, yet
+on waking we imagine that we have been dreaming for an immensely long
+period. This retrospective appreciation is determined by the number and
+the degree or intensity of the experiences, and, what comes very much to
+the same thing, by the amount of unlikeness, freshness, and
+discontinuity characterizing these experiences.
+
+Time, as I have already hinted, is known under the form of a succession
+of different conscious experiences. Unbroken uniformity would give us no
+sense of time, because it would give us no conscious experience at all.
+Strictly speaking, there is no such thing as a perfectly uniform mental
+state extending through an appreciable duration. In looking at one and
+the same object, even in listening to one and the same tone, I am in no
+two successive fractions of a second in exactly the same state of mind.
+Slight alterations in the strength of the sensation,[123] in the degree
+or direction of attention, and in the composition of that penumbra of
+vague images which it calls up, occur at every distinguishable fraction
+of time.
+
+This being so, it would seem to follow that the greater the number of
+clearly marked changes, and the more impressive and exciting these
+transitions, the fuller will be our sense of time. And this is borne out
+by individual reflection. When striking and deeply interesting events
+follow one another very rapidly, as when we are travelling, duration
+appears to swell out.
+
+It is possible that such a succession of stirring experiences may beget
+a vague consciousness of time at each successive moment, and apart from
+retrospection, simply by force of the change. In other words, without
+our distinctly attending to time, a series of novel impressions might,
+by giving us the consciousness of change, make us dimly aware of the
+numerical richness of our experiences. But, however this be, there is no
+doubt that, in glancing back on such a succession of exciting
+transitions of mental condition, time appears to expand enormously, just
+as it does in looking back on our dream-experience, or that rapid series
+of intensified feelings which, according to De Quincey and others, is
+produced by certain narcotics.
+
+The reason of this is plain. Such a type of successive experience offers
+to the retrospective imagination a large number of distinguishable
+points, and since this mode of estimating time depends, as we have seen,
+on the extent of the process of filling in, time will necessarily appear
+long in this case. On the other hand, when we have been engaged in very
+ordinary pursuits, in which few deeply interesting or exciting events
+have impressed themselves on memory, our retrospective picture will
+necessarily be very much of a blank, and consequently the duration of
+the period will seem to be short.
+
+I observed that this retrospective appreciation of time depended on the
+degree of connection between the successive experiences. This condition
+is very much the same as the other just given, namely, the degree of
+uniformity of the experiences, since the more closely the successive
+stages of the experience are connected--as when, for example, we are
+going through our daily routine of work--the more quiet and unexciting
+will be the transition from each stage to its succeeding one. And on the
+other hand, all novelty of impression and exciting transition of
+experience clearly involves a want of connection. Wundt thinks the
+retrospective estimate of a connected series of experiences, such as
+those of our daily round of occupations, is defective just because the
+effort of attention, which precedes even an imaginative reproduction of
+an impression, so quickly accommodates itself in this case to each of
+the successive steps, whereas, when the experiences to be recalled are
+disconnected, the effort requires more time. In this way, the estimate
+of a past duration would be coloured by the sense of time accompanying
+the reproductive process itself. This may very likely be the case, yet I
+should be disposed to attach most importance to the number of
+distinguishable items of experience recalled.
+
+Our representation of the position of a given event in the past is, as I
+have tried to show, determined by the movement of imagination in going
+back to it from the present. And this is the same thing as to say that
+it depends on our retrospective sense of the intervening space. That is
+to say, the sense of distance in time, as in space, is the recognition
+of a term to a movement. And just as the distance of an object will seem
+greater when there are many intervening objects affording points of
+measurement, than when there are none (as on the uniform surface of the
+sea), so the distance of an event will vary with the number of
+recognized intervening points.
+
+The appreciation of the distance of an event in time does not, however,
+wholly depend on the character of this movement of imagination. Just as
+the apparent distance of a visible object depends _inter alia_ on the
+distinctness of the retinal impression, so the apparent temporal
+remoteness of a past event depends in part on the degree of intensity
+and clearness of the mnemonic image. This is seen even in the case of
+those images which we are able distinctly to localize in the
+time-perspective. For a series of exciting experiences intervening
+between the present and a past event appears not only _directly_ to add
+to our sense of distance by constituting an apparently long interval,
+but _indirectly_ to add to it by giving an unusual degree of faintness
+to the recalled image. An event preceding some unusually stirring series
+of experiences gets thrust out of consciousness by the very engrossing
+nature of the new experiences, and so tends to grow more faint and
+ghost-like than it would otherwise have done.
+
+The full force of this circumstance is best seen in the fact that a very
+recent event, bringing with it a deep mental shock and a rapid stirring
+of wide tracts of feeling and thought, may get to look old in a
+marvellously short space of time. An announcement of the loss of a dear
+friend, when sudden and deeply agitating, will seem remote even after an
+hour of such intense emotional experience. And the same twofold
+consideration probably explains the well-known fact that a year seems
+much shorter to the adult than to the child. The novel and comparatively
+exciting impressions of childhood tend to fill out time in retrospect,
+and also to throw back remote events into a dimly discernible region.
+
+Now, this same circumstance, the degree of vividness or of faintness of
+the mnemonic image, is that which determines our idea of distance when
+the character of the intervening experiences produces no appreciable
+effect.[124] This is most strikingly illustrated in those imperfect
+kinds of recollection in which we are unable to definitely localize the
+mnemonic image. To the consideration of these we will now turn.
+
+
+B. _Indefinite Localization._
+
+Speaking roughly and generally, we may say that the vividness of an
+image of memory decreases in proportion as the distance of the event
+increases. And this is the rule which we unconsciously apply in
+determining distance in time. Nevertheless, this rule gives us by no
+means an infallible criterion of distance. The very fact that different
+people so often dispute about the dates and the order of past events
+experienced in common, shows pretty plainly that images of the same age
+tend to arise in the mind with very unequal degrees of vividness.
+
+Sometimes pictures of very remote incidents may suddenly present
+themselves to our minds with a singular degree of brightness and force.
+And when this is the case, there is a disposition to think of them as
+near. If the relations of the event to other events preceding and
+succeeding it are not remembered, this momentary illusion will persist.
+We have all heard persons exclaim, "It seems only yesterday," under the
+sense of nearness which accompanies a recollection of a remote event
+when vividly excited. The most familiar instance of such lively
+reproduction is the feeling which we experience on revisiting the scene
+of some memorable event. At such a time the past may return with
+something of the insistence of a present perceived reality. In passing
+from place to place, in talking with others, and in reading, we are
+liable to the sudden return by hidden paths of association of images of
+incidents that had long seemed forgotten, and when they thus start up
+fresh and vigorous, away from their proper surroundings, they invariably
+induce a feeling of the propinquity of the events.
+
+In many cases we cannot say why these particular images, long buried in
+oblivion, should thus suddenly regain so much vitality. There seems,
+indeed, to be almost as much that is arbitrary and capricious in the
+selection by memory of its vivid images as in the selection of its
+images as a whole; and, this being so, it is plain that we are greatly
+exposed to the risk of illusion from this source.
+
+There is an opposite effect in the case of recent occurrences that, for
+some reason or another, have left but a faint impression on the memory;
+though this fact is not, perhaps, so familiar as the other. I met a
+friend, we will suppose, a few days since at my club, and we exchanged a
+few words. My mind was somewhat preoccupied at the time, and the
+occurrence did not stamp itself on my recollection. To-day I meet him
+again, and he reminds me of a promise I made him at the time. His
+reminder suffices to restore a dim image of the incident, but the fact
+of its dimness leads to the illusion that it really happened much longer
+ago, and it is only on my friend's strong assurances, and on reasoning
+from other data that it must have occurred the day he mentions, that I
+am able to dismiss the illusion.
+
+The most striking examples of the illusory effect of mere vividness,
+involving a complete detachment of the event from the prominent
+landmarks of the past, are afforded by public events which lie outside
+the narrower circle of our personal life, and which do not in the
+natural course of things become linked to any definitely localized
+points in the field of memory. These events may be very stirring and
+engrossing for the time, but in many cases they pass out of the mind
+just as suddenly as they entered it. We have no occasion to revert to
+them, and if by chance we are afterwards reminded of them, they are
+pretty certain to look too near, just because the fact of their having
+greatly interested us has served to render their images particularly
+vivid.
+
+A curious instance of this illusory effect was supplied not long since
+by the case of the ex-detectives, the expiration of whose term of
+punishment (three years) served as an occasion for the newspapers to
+recall the event of their trial and conviction. The news that three
+years had elapsed since this well-remembered occurrence proved very
+startling to myself, and to a number of my friends, all of us agreeing
+that the event did not seem to be at more than a third of its real
+distance. More than one newspaper commented on the apparent rapidity of
+the time, and this shows pretty plainly that there was some cause at
+work, such as I have suggested, producing a common illusion.
+
+I have treated of these illusions connected with the estimate of past
+time and the dating of past events as passive illusions, not involving
+any active predisposition on the part of the imagination. At the same
+time, it is possible that error in these matters may occasionally depend
+on a present condition of the feelings and the imagination. It seems
+plain that since the apparent degree of remoteness of an event not
+distinctly localized in the past varies inversely as the degree of
+vividness of the mnemonic image, any conscious concentration of mind on
+a recollection will tend to bring it too near. In this way, then, an
+illusory propinquity may be given to a recalled event through a mere
+desire to dwell on it, or even a capricious wish to deceive one's self.
+
+When, for example, old friends come together and talk over the days of
+yore, there is a gradual reinstatement of seemingly lost experiences,
+which often partakes of the character of a semi-voluntary process of
+self-delusion. Through the cumulative effect of mutual reminder,
+incident after incident returns, adding something to the whole picture
+till it acquires a degree of completeness, coherence, and vividness that
+render it hardly distinguishable from a very recent experience. The
+process is like looking at a distant object through a field-glass.
+Mistiness disappears, fresh details come into view, till we seem to
+ourselves to be almost within reach of the object.
+
+Where the mind habitually goes back to some painful circumstance under
+the impulse of a morbid disposition to nurse regret, this momentary
+illusion may become recurring, and amount to a partial confusion of the
+near and the remote in our experience. An injury long brooded on seems
+at length a thing that continually moves forward as we move; it always
+presents itself to our memories as a very recent event. In states of
+insanity brought on by some great shock, we see this morbid tendency to
+resuscitate the dead past fully developed, and remote events and
+circumstances becoming confused with present ones.
+
+On the other hand, in more healthy states of mind there presents itself
+an exactly opposite tendency, namely, an impulse of the will to banish
+whatever when recalled gives pain to the furthest conceivable regions of
+the past. Thus, when we have lost something we cherished dearly, and the
+recollection of it brings fruitless longing, we instinctively seek to
+expel the recollection from our minds. The very feeling that what has
+been can never again be, seems to induce this idea of a vast remoteness
+of the vanished reality. When, moreover, the lost object was fitted to
+call forth the emotion of reverence, the impulse to magnify the
+remoteness of the loss may not improbably be reinforced by the
+circumstance that everything belonging to the distant past is fitted on
+that account to excite a feeling akin to reverence. So, again, any
+rupture in our mental development may lead us to exaggerate the distance
+of some past portion of our experience. When we have broken with our
+former selves, either in the way of worsening or bettering, we tend to
+project these further into the past.
+
+It is only when the sting of the recollection is removed, when, for
+example, the calling up of the image of a lost friend is no longer
+accompanied with the bitterness of futile longing, that a healthy mind
+ventures to nourish recollections of such remote events and to view
+these as part of its recent experiences. In this case the mnemonic image
+becomes transformed into a kind of present emotional possession, an
+element of that idealized and sublimated portion of our experience with
+which all imaginative persons fill up the emptiness of their actual
+lives, and to which the poet is wont to give an objective embodiment in
+his verse.
+
+
+_Distortions of Memory._
+
+It is now time to pass to the second group of illusions of memory,
+which, according to the analogy of visual errors, may be called
+atmospheric illusions. Here the degree of error is greater than in the
+case of illusions of time-perspective, since the very nature of the
+events or circumstances is misconceived. We do not recall the event as
+it happened, but see it in part only, and obscured, or bent and
+distorted as by a process of refraction. Indeed, this transformation of
+the past does closely correspond with the transformation of a visible
+object effected by intervening media. Our minds are such refracting
+media, and the past reappears to us not as it actually was when it was
+close to us, but in numerous ways altered and disguised by the
+intervening spaces of our conscious experience.
+
+To begin with, what we call recollection is uniformly a process of
+softening the reality. When we appear to ourselves to realize events of
+the remote past, it is plain that our representation in a general way
+falls below the reality: the vividness, the intensity of our impressions
+disappears. More particularly, so far as our experiences are emotional,
+they tend thus to become toned down by the mere lapse of time and the
+imperfections of our reproductive power. That which we seem to see in
+the act of recollection is thus very different from the reality.
+
+Not only is there this general deficiency in mnemonic representation,
+there are special deficiencies due to the fact of oblivescence. Our
+memories restore us only fragments of our past life. And just as objects
+seen imperfectly at a great distance may assume a shape quite unlike
+their real one, so an inadequate representation of a past event by
+memory often amounts to misrepresentation. When revisiting a place that
+we have not seen for many years, we are apt to find that our
+recollection of it consisted only of some insignificant details, which
+arranged themselves in our minds into something oddly unlike the actual
+scene. So, too, some accidental accompaniment of an incident in early
+life is preserved, as though it were the main feature, serving to give
+quite a false colouring to the whole occurrence.
+
+It seems quite impossible to account for these particular survivals,
+they appear to be so capricious. When a little time has elapsed after an
+event, and the attendant circumstances fade away from memory, it is
+often difficult to say why we were impressed with it as we afterwards
+prove to have been. It is no doubt possible to see that many of the
+recollections of our childhood owe their vividness to the fact of the
+exceptional character of the events; but this cannot always be
+recognized. Some of them seem to our mature minds very oddly selected,
+although no doubt there are in every case good reasons, if we could only
+discover them, why those particular incidents rather than any others
+should have been retained.
+
+The liability to error resulting from mere oblivescence and the
+arbitrary selection of mental images is seen most plainly, perhaps, in
+our subsequent representation and estimate of whole periods of early
+life. Our idea of any stage of our past history, as early childhood, or
+school days, is built up out of a few fragmentary intellectual relics
+which cannot be certainly known to answer to the most important and
+predominant experiences of the time. When, for example, we try to decide
+whether our school days were our happiest days, as is so often alleged,
+it is obvious that we are liable to fall into illusion through the
+inadequacy of memory to preserve characteristic or typical features, and
+none but these. We cannot easily recall the ordinary every-day level of
+feeling of a distant period of life, but rather think of exceptional
+moments of rejoicing or depression. The ordinary man's idea of the
+emotional experience of his school days is probably built up out of a
+few scrappy recollections of extraordinary and exciting events, such as
+unexpected holidays, success in the winning of prizes, famous "rows"
+with the masters, and so on.
+
+Besides the impossibility of getting at the average and prevailing
+mental tone of a distant section of life, there is a special difficulty
+in determining the degree of happiness of the past, arising from the
+fact that our memory for pleasures and for pains may not be equally
+good. Most people, perhaps, can recall the enjoyments of the past much
+more vividly than the sufferings. On the other hand, there seem to be
+some who find the retention of the latter the easier of the two. This
+fact should not be forgotten in reading the narrative of early hardships
+which some recent autobiographies have given us.
+
+Not only does our idea of the past become inexact by the mere decay and
+disappearance of essential features, it becomes positively incorrect
+through the gradual incorporation of elements that do not properly
+belong to it. Sometimes it is easy to see how these extraneous ideas get
+imported into our mental representation of a past event. Suppose, for
+example, that a man has lost a valuable scarf-pin. His wife suggests
+that a particular servant, whose reputation does not stand too high, has
+stolen it. When he afterwards recalls the loss, the chances are that he
+will confuse the fact with the conjecture attached to it, and say he
+remembers that this particular servant did steal the pin. Thus, the past
+activity of imagination serves to corrupt and partially falsify
+recollections that have a genuine basis of fact.
+
+It is evident that this class of mnemonic illusions approximates in
+character to illusions of perception. When the imagination supplies the
+interpretation at the very time, and the mind reads this into the
+perceived object, the error is one of perception. When the addition is
+made afterwards, on reflecting upon the perception, the error is one of
+memory. The "fallacies of testimony" which depend on an adulteration of
+pure observation with inference and conjecture, as, for example, the
+inaccurate and wild statements of people respecting their experiences at
+spiritualist _seances_, while they illustrate the curious blending of
+both kinds of error, are probably much oftener illusions of memory than
+of perception.[125]
+
+Although in many cases we can account to ourselves for this confusion of
+fact and imagination, in other cases it is difficult to see any close
+relation between the fact remembered and the foreign element imported
+into it. An idea of memory seems sometimes to lose its proper moorings,
+so to speak; to drift about helplessly among other ideas, and finally,
+by some chance, to hook itself on to one of these, as though it
+naturally belonged to it. Anybody who has had an opportunity of
+carefully testing the truthfulness of his recollection of some remote
+event in early life will have found how oddly extraneous elements become
+incorporated into the memorial picture. Incidents get put into wrong
+places, the wrong persons are introduced into a scene, and so on. Here
+again we may illustrate the mnemonic illusion by a visual one. When a
+tree standing before or behind a house and projecting above or to the
+side of it is not sharply distinguished from the latter, it may serve to
+give it a very odd appearance.
+
+These confusions of the mental image may arise even when only a short
+interval has elapsed. In the case of many of the fleeting impressions
+that are only half recollected, this kind of error is very easy. Thus,
+for example, I may have lent a book to a friend last week. I really
+remember the act of lending it, but have forgotten the person. But I am
+not aware of this. The picture of memory has unknowingly to myself been
+filled up by this unconscious process of shifting and rearrangement, and
+the idea of another person has by some odd accident got substituted for
+that of the real borrower. If we could go deeply enough into the matter,
+we should, of course, be able to explain why this particular confusion
+arose. We might find, for example, that the two persons were associated
+in my mind by a link of resemblance, or that I had dealings with the
+other person about the same time. Similarly, when we manage to join an
+event to a wrong place, we may find that it is because we heard of the
+occurrence when staying at the particular locality, or in some other way
+had the image of the place closely associated in our minds with the
+event. But often we are wholly unable to explain the displacement.
+
+So far I have been speaking of the passive processes by which the past
+comes to wear a new face to our imaginations. In these our present
+habits of feeling and thinking take no part; all is the work of the
+past, of the decay of memory, and the gradual confusion of images. This
+process of disorganization may be likened to the action of damp on some
+old manuscript, obliterating some parts, altering the appearance of
+others, and even dislocating certain portions. Besides this passive
+process of transformation, there is a more active one in which our
+present minds co-operate. In memory, as in perception and introspection,
+there is a process of preparation or preadjustment of mind, and here
+will be found room for what I had called active error. This may be
+illustrated by the operation of "interpreting" an old manuscript which
+has got partially obliterated, or of "restoring" a faded picture; in
+each of which operations error will be pretty sure to creep in through
+an importation of the restorer's own ideas into the relic of the past.
+
+Just as when distant objects are seen mistily our imaginations come into
+play, leading us to fancy that we see something completely and
+distinctly, so when the images of memory become dim, our present
+imagination helps to restore them, putting a new patch into the old
+garment. If only there is some relic of the past event preserved, a bare
+suggestion of the way in which it may have happened will often suffice
+to produce the conviction that it actually did happen in this way. The
+suggestions that naturally arise in our minds at such times will bear
+the stamp of our present modes of experience and habits of thought.
+Hence, in trying to reconstruct the remote past, we are constantly in
+danger of importing our present selves into our past selves.
+
+The kind of illusion of memory which thus depends on the spontaneous or
+independent activity of present imagination is strikingly illustrated in
+the curious cases of mistaken identity with which the proceedings of
+our law courts supply us from time to time. When a witness in good
+faith, but erroneously, affirms that a man is the same as an old
+acquaintance of his, we may feel sure that there is some striking point
+or points of similarity between the two persons. But this of itself
+would only partly account for the illusion, since we often see new faces
+that, by a number of curious points of affinity, call up in a
+tantalizing way old and familiar ones. What helps in this case to
+produce the illusion is the preconception that the present man is the
+witness's old friend. That is to say, his recollection is partly true,
+though largely false. He does really recall the similar feature,
+movement, or tone of voice; he only seems to himself to recall the rest
+of his friend's appearance; for, to speak correctly, he projects the
+present impression into the past, and constructs his friend's face out
+of elements supplied by the new one. Owing to this cause, an illusion of
+memory is apt to multiply itself, one man's assertion of what happened
+producing by contagion a counterfeit of memory's record in other minds.
+
+I said just now that we tend to project our present modes of experience
+into the past. We paint our past in the hues of the present. Thus we
+imagine that things which impressed us in some remote period of life
+must answer to what is impressive in our present stage of mental
+development. For example, a person recalls a hill near the home of his
+childhood, and has the conviction that it was of great height. On
+revisiting the place he finds that the eminence is quite insignificant.
+How can we account for this? For one thing, it is to be observed that to
+his undeveloped childish muscles the climbing to the top meant a
+considerable expenditure of energy, to be followed by a sense of
+fatigue. The man remembers these feelings, and "unconsciously reasoning"
+by present experience, that is to say, by the amount of walking which
+would now produce this sense of fatigue, imagines that the height was
+vastly greater than it really was. Another reason is, of course, that a
+wider knowledge of mountains has resulted in a great alteration of the
+man's standard of height.
+
+From this cause arises a tendency generally to exaggerate the
+impressions of early life. Youth is the period of novel effects, when
+all the world is fresh, and new and striking impressions crowd in
+thickly on the mind. Consequently, it takes much less to produce a given
+amount of mental excitation in childhood than in after-life. In looking
+back on this part of our history, we recall for the most part just those
+events and scenes which deeply stirred our minds by their strangeness,
+novelty, etc., and so impressed themselves on the tablet of our memory;
+and it is this sense of something out of the ordinary beat that gives
+the characteristic colour to our recollection. In other words, we
+remember something as wonderful, admirable, exceptionally delightful,
+and so on, rather than as a definitely imagined event. This being so, we
+unconsciously transform the past occurrence by reasoning from our
+present standard of what is impressive. Who has not felt an unpleasant
+disenchantment on revisiting some church, house, or park that seemed a
+wondrous paradise to his young eyes? All our feelings are capable of
+leading us into this kind of illusion. What seemed beautiful or awful
+to us as children, is now pictured in imagination as corresponding to
+what moves our mature minds to delight or awe. One cannot help wondering
+what we should think of our early heroes or heroines if we could see
+them again with our adult eyes exactly as they were.
+
+While the past may thus take on an illusory hue through the very
+progress of our experience and our emotional life, it may become further
+transformed by a more conscious process, namely, the idealizing touch of
+a present feeling. The way in which the emotions of love, reverence, and
+so on, thus transform their lost objects is too well known to need
+illustration. Speaking generally, we may say that in healthy minds the
+play of these impulses of feeling results in a softening of the harsher
+features of the past, and in an idealization of its happier and brighter
+aspects. As Wordsworth says, we may assign to Memory a pencil--
+
+  "That, softening objects, sometimes even
+     Outstrips the heart's demand;
+
+  "That smoothes foregone distress, the lines
+     Of lingering care subdues,
+   Long-vanished happiness refines,
+     And clothes in brighter hues."[126]
+
+Enough has now been said, perhaps, to show in how many ways our
+retrospective imagination transforms the actual events of our past life.
+So thoroughly, indeed, do the relics of this past get shaken together in
+new kaleidoscopic combinations, so much of the result of later
+experiences gets imported into our early years, that it may well be
+asked whether, if the record of our actual life were ever read out to
+us, we should be able to recognize it. It looks as though we could be
+sure of recalling only recent events with any degree of accuracy and
+completeness. As soon as they recede at any considerable distance from
+us, they are subject to a sort of atmospheric effect. Much grows
+indistinct and drops altogether out of sight, and what is still seen
+often takes a new and grotesquely unlike shape. More than this, the play
+of fancy, like the action of some refracting medium, bends and distorts
+the outlines of memory's objects, making them wholly unlike the
+originals.
+
+
+_Hallucinations of Memory._
+
+We will now go on to the third class of mnemonic error, which I have
+called the spectra of memory, where there is not simply a transformation
+of the past event, but a complete imaginative creation of it. This class
+of error corresponds, as I have observed, to an hallucination in the
+region of sense-perception. And just as we distinguished between those
+hallucinations of sense which arise first of all through some
+peripherally caused subjective sensation, and those which want even this
+element of reality and depend altogether on the activity of imagination,
+so we may mark off two classes of mnemonic hallucination. The false
+recollection may correspond to something past--and to this extent be a
+recollection--though not to any objective fact, but only to a subjective
+representation of such a fact, as, for example, a dream. In this case
+the imitation of the mnemonic process may be very definite and complete.
+Or the false recollection may be wholly a retrojection of a present
+mental image, and so by no stretch of language be deserving of the name
+recollection.
+
+It is doubtful whether by any effort of will a person could bring
+himself to regard a figment of his present imagination as representative
+of a past reality. Definite and complete hallucinations of this sort do
+not in normal circumstances arise. It seems necessary for a complete
+illusion of memory that there should be something past and recovered at
+the moment, though this may not be a real personal experience.[127] On
+the other hand, it is possible, as we shall presently see, under certain
+circumstances, to create out of present materials, and in a vague and
+indefinite shape, pure phantoms of past experience, that is to say,
+quasi-mnemonic images to which there correspond no past occurrences
+whatever.
+
+All recollection, as we have seen, takes place by means of a present
+mental image which returns with a certain degree of vividness, and is
+instantaneously identified with some past event. In many cases this
+instinctive process of identification proves to be legitimate, for, as a
+matter of fact, real impressions are the first and the commonest source
+of such lively mnemonic images. But it is not always so. There are other
+sources of our mental imagery which compete, so to speak, with the
+region of real personal experience. And sometimes these leave behind
+them a vivid image having all the appearance of a genuine mnemonic
+image. When this is so, it is impossible by a mere introspective glance
+to detect the falsity of the message from the past. We are in the same
+position as the purchaser in a jet market, where a spurious commodity
+has got inextricably mixed up with the genuine, and there is no ready
+criterion by which he can distinguish the true from the false. Such a
+person, if he purchases freely, is pretty sure to make a number of
+mistakes. Similarly, all of us are liable to take counterfeit mnemonic
+images for genuine ones; that is to say, to fall into an illusion of
+"recollecting" what never really took place.
+
+But what, it may be asked, are these false and illegitimate sources of
+mnemonic images, these unauthorized mints which issue a spurious mental
+coinage, and so confuse the genuine currency? They consist of two
+regions of our internal mental life, which most closely resemble the
+actual perception of real things in vividness and force, namely,
+dream-consciousness and waking imagination. Each of these may introduce
+into the mind vivid images which afterwards tend, under certain
+circumstances, to assume the guise of recollections of actual events.
+
+That our dream-experience may now and again lead us into illusory
+recollection has already been hinted. And it is easy to understand why
+this is so. When dreaming we have, as we have seen, a mental experience
+which closely approximates in intensity and reality to that of waking
+perception. Consequently, dreams may leave behind them, for a time,
+vivid images which simulate the appearance of real images of memory.
+Most of us, perhaps, have felt this after-effect of dreaming on our
+waking thoughts. It is sometimes very hard to shake off the impression
+left by a vivid dream, as, for example, that a dead friend has returned
+to life. During the day that follows the dream, we have at intermittent
+moments something like an assurance that we have seen our lost friend;
+and though we immediately correct the impression by reflecting that we
+are recalling but a dream, it tends to revive within us with a strange
+pertinacity.
+
+In addition to this proximate effect of a dream in disturbing the normal
+process of recollection, there is reason to suppose that dreams may
+exert a more remote effect on our memories. So widely different in its
+form is our dreaming from our waking experience, that our dreams are
+rarely recalled as wholes with perfect distinctness. They revive in us
+only as disjointed fragments, and only for brief moments when some
+accidental resemblance in the present happens to stir the latent trace
+they have left on our minds. We get sudden flashes out of our
+dream-world, and the process is too rapid, too incomplete for us to
+identify the region whence the flashes come.
+
+It is highly probable that our dreams are, to a large extent, answerable
+for the sense of familiarity that we sometimes experience in visiting a
+new locality or in seeing a new face. If, as we have found some of the
+best authorities saying, we are, when asleep, always dreaming more or
+less distinctly, and if, as we know, dreaming is a continual process of
+transformation of our waking impressions in new combinations, it is not
+surprising that our dreams should sometimes take the form of forecasts
+of our waking life, and that consequently objects and scenes of this
+life never before seen should now and again wear a familiar look.
+
+That some instances of this puzzling sense of familiarity can be
+explained in this way is proved. Thus, Paul Radestock, in the work
+_Schlaf und Traum_, already quoted, tells us: "When I have been taking a
+walk, with my thoughts quite unfettered, the idea has often occurred to
+me that I had seen, heard, or thought of this or that thing once before,
+without being able to recall when, where, and in what circumstances.
+This happened at the time when, with a view to the publication of the
+present work, I was in the habit of keeping an exact record of my
+dreams. Consequently, I was able to turn to this after these
+impressions, and on doing so I generally found the conjecture confirmed
+that I had previously dreamt something like it." Scientific inquiry is
+often said to destroy all beautiful thoughts about nature and life; but
+while it destroys it creates. Is it not almost a romantic idea that just
+as our waking life images itself in our dreams, so our dream-life may
+send back some of its shadowy phantoms into our prosaic every-day world,
+touching this with something of its own weird beauty?
+
+Not only may dreams beget these momentary illusions of memory, they may
+give rise to something like permanent illusions. If a dream serves to
+connect a certain idea with a place or person, and subsequent experience
+does not tend to correct this, we may keep the belief that we have
+actually witnessed the event. And we may naturally expect that this
+result will occur most frequently in the case of those who habitually
+dream vividly, as young children.
+
+It seems to me that many of the quaint fancies which children get into
+their heads about things they hear of arise in this way. I know a person
+who, when a child, got the notion that when his baby-brother was weaned,
+he was taken up on a grassy hill and tossed about. He had a vivid idea
+of having seen this curious ceremony. He has in vain tried to get an
+explanation of this picturesque rendering of an incident of babyhood
+from his friends, and has come to the conclusion that it was the result
+of a dream. If, as seems probable, children's dreams thus give rise to
+subsequent illusions of memory, the fact would throw a curious light on
+some of the startling quasi-records of childish experience to be met
+with in autobiographical literature.
+
+Odd though it may at first appear, old age is said to resemble youth in
+this confusion of dream-recollection with the memory of waking
+experience. Dr. Carpenter[128] tells us of "a lady of advanced age
+who ... continually dreams about passing events, and seems entirely unable
+to distinguish between her dreaming and her waking experiences,
+narrating the former with implicit belief in them, and giving directions
+based on them." This confusion in the case of the old may possibly
+arise not from an increase in the intensity of the dreams, but from a
+decrease in the intensity of the waking impressions. As Sir Henry
+Holland remarks,[129] in old age life approaches to the state of a
+dream.
+
+The other source of what may, by analogy with the hallucinations of
+sense, be called the peripherally originating spectra of memory is
+waking imagination. In certain morbid conditions of mind, and in the
+case of the few healthy minds endowed with special imaginative force,
+the products of this mental activity, may, as we saw when dealing with
+illusions of perception, closely resemble dreams in their vividness and
+apparent actuality. When this is the case, illusions of memory may arise
+at once just as in the case of dreams. This will happen more easily when
+the imagination has for some time been occupied with the same group of
+ideal scenes, persons, or events. To Dickens, as is well known, his
+fictitious characters were for the time realities, and after he had
+finished his story their forms and their doings lingered with him,
+assuming the aspect of personal recollections. So, too, the energetic
+activity of imagination which accompanies a deep and absorbing sympathy
+with another's painful experiences, may easily result in so vivid a
+realization of all their details as to leave an after-sense of
+_personal_ suffering. All highly sympathetic persons who have closely
+accompanied beloved friends through a great sorrow have known something
+of this subsequent feeling.
+
+The close connection and continuity between normal and abnormal states
+of mind is illustrated in the fact that in insanity the illusion of
+taking past imaginations for past realities becomes far more powerful
+and persistent. Abercrombie (_Intellectual Powers_, Part III. sec. iv. Sec.
+2, "Insanity") speaks of "visions of the imagination which have formerly
+been indulged in of that kind which we call waking dreams or
+castle-building recurring to the mind in this condition, and now
+believed to have a real existence." Thus, for example, one patient
+believed in the reality of the good luck previously predicted by a
+fortune-teller. Other writers on mental disease observe that it is a
+common thing for the monomaniac to cherish the delusion that he has
+actually gained the object of some previous ambition, or is undergoing
+some previously dreaded calamity.
+
+Nor is it necessary to these illusions of memory that there should be
+any exceptional force of imagination. A fairly vivid representation to
+ourselves of anything, whether real or fictitious, communicated by
+others, will often result in something very like a personal
+recollection. In the case of works of history and fiction, which adopt
+the narrative tense, this tendency to a subsequent illusion of memory is
+strengthened by the disposition of the mind at the moment of reading to
+project itself backwards as in an act of recollection. This is a point
+which will be further dealt with in the next chapter.
+
+In most cases, however, illusions of memory growing out of previous
+activities of the imagination appear only after the lapse of some time,
+when in the natural course of things the mental images derived from
+actual experience would sink to a certain degree of faintness. Habitual
+novel-readers often catch themselves mistaking the echo of some passage
+in a good story for the trace left by an actual event. A person's name,
+a striking saying, and even an event itself, when we first come across
+it or experience it, may for a moment seem familiar to us, and to recall
+some past like impression, if it only happens to resemble something in
+the works of a favourite novelist. And so, too, any recital of another's
+experience, whether oral or literary, if it deeply interests us and
+awakens a specially vivid imagination of the events described, may
+easily become the starting-point of an illusory recollection.
+
+Children are in the habit of "drinking in" with their vigorous and eager
+imaginations what is told them and read to them, and hence they are
+specially likely to fall into this kind of error. Not only so: when they
+grow up and their early recollections lose their definiteness, becoming
+a few fragments saved from a lost past, it must pretty certainly happen
+that if any ideas derived from these recitals are preserved, they will
+simulate the form of memories. Thus, I have often caught myself for a
+moment under the sway of the illusion that I actually visited the
+Exhibition of 1851, the reason being that I am able to recall the
+descriptions given to me of it by my friends, and the excitement
+attending their journey to London on the occasion. It is to be added
+that repetition of the act of imagination will tend still further to
+deepen the subsequent feeling that we are recollecting something. As
+Hartley well observes, a man, by repeating a story, easily comes to
+suppose that he remembers it.[130]
+
+Here, then, we have another source of error that we must take into
+account in judging of the authenticity of an autobiographical narration
+of the events of childhood. The more imaginative the writer, the greater
+the risk of illusion from this source as well as from that of
+dream-fancies. It is highly probable, indeed, that in such full and
+explicit records of very early life as those given by Rousseau, by
+Goethe, or by De Quincey, some part of the quasi-narrative is based on
+mental images which come floating down the stream of time, not from the
+substantial world of the writer's personal experience, but from the airy
+region of dream-land or of waking fancy.
+
+It is to be added that even when the quasi-recollection does answer to a
+real event of childish history, it may still be an illusion. The fact
+that others, in narrating events to us, are able to awaken imaginations
+that afterwards appear as past realities, suggests that much of our
+supposed early recollection owes its existence to what our parents and
+friends have from time to time told us respecting the first stages of
+our history.[131] We see, then, how much uncertainty attaches to all
+autobiographical description of very early life.
+
+Modern science suggests another possible source of these distinct
+spectra of memory. May it not happen that, by the law of hereditary
+transmission, which is now being applied to mental as well as bodily
+phenomena, ancestral experiences will now and then reflect themselves
+in our mental life, and so give rise to apparently personal
+recollections? No one can say that this is not so. When the infant first
+steadies his eyes on a human face, it may, for aught we know, experience
+a feeling akin to that described above, when through a survival of
+dream-fancy we take some new scene to be already familiar. At the age
+when new emotions rapidly develop themselves, when our hearts are full
+of wild romantic aspirations, do there not seem to blend with the eager
+passion of the time deep resonances of a vast and mysterious past, and
+may not this feeling be a sort of reminiscence of prenatal, that is,
+ancestral experience?
+
+This idea is certainly a fascinating one, worthy to be a new scientific
+support for the beautiful thought of Plato and of Wordsworth. But in our
+present state of knowledge, any reasoning on this supposition would
+probably appear too fanciful. Some day we may find out how much
+ancestral experience is capable of bequeathing in this way, whether
+simply shadowy, undefinable mental tendencies, or something like
+definite concrete ideas. If, for example, it were found that a child
+that was descended from a line of seafaring ancestors, and that had
+never itself seen or heard of the "dark-gleaming sea," manifested a
+feeling of recognition when first beholding it, we might be pretty sure
+that such a thing as recollection of prenatal events does take place.
+But till we have such facts, it seems better to refer the "shadowy
+recollections" to sources which fall within the individual's own
+experience.
+
+We may now pass to those hallucinations of memory which are analogous to
+the _centrally_ excited hallucinations of sense-perception. As I have
+observed, these are necessarily vague and imperfectly developed.
+
+I have already had occasion to touch on the fact of the vast amount of
+our forgotten experience. And I observed that forgetfulness was a common
+negative condition of mnemonic illusion. I have now to complete this
+statement by the observation that total forgetfulness of any period or
+stage of our past experience necessarily tends to a vague kind of
+hallucination. In looking back on the past, we see no absolute gaps in
+the continuity of our conscious life; our image of this past is
+essentially one of an unbroken series of conscious experiences. But if
+through forgetfulness a part of the series is effaced from memory, how,
+it may be asked, is it possible to construct this perfectly continuous
+line? The answer is that we fill up such lacunae vaguely by help of some
+very imperfectly imagined common type of conscious experience. Just as
+the eye sees no gap in its field of vision corresponding to the "blind
+spot" of the retina, but carries its impression over this area, so
+memory sees no lacuna in the past, but carries its image of conscious
+life over each of the forgotten spaces.
+
+Sometimes this process of filling in gaps in the past becomes more
+complete. Thus, for example, in recalling a particular night a week or
+so ago, I instinctively represent it to myself as so many hours of lying
+in bed with the waking sensations appropriate to the circumstances, as
+those of bodily warmth and rest, and of the surrounding silence and
+darkness.
+
+It is apparent that I cannot conceive myself apart from some mode of
+conscious experience. In thinking of myself in any part of the past or
+future in which there is actually no consciousness, or of which the
+conscious content is quite unknown to me, I necessarily imagine myself
+as consciously experiencing something. If I picture myself under any
+definitely conceived circumstances, I irresistibly import into my mental
+image the feelings appropriate to these surroundings. In this way,
+people tend to imagine themselves after death as lying in the grave,
+feeling its darkness and its chilliness. If the circumstances of the
+time are not distinctly represented, the conception of the conscious
+experience which constitutes that piece of the ego is necessarily vague,
+and seems generally to resolve itself into a representation of ourselves
+as dimly _self-conscious_. What this consciousness of self consists of
+is a point that will be taken up presently.
+
+
+_Illusions with respect to Personal Identity._
+
+It would seem to follow from these errors in imaginatively filling up
+our past life, that our consciousness of personal identity is by no
+means the simple and exact process which it is commonly supposed to be.
+I have already remarked that the very fact of there being so large a
+region of the irrevocable in our past experience proves our
+consciousness of personal continuity to be largely a matter of
+inference, or of imaginative conjecture, and not simply of immediate
+recollection. Indeed, it may be said that our power of ignoring whole
+regions of the past and of leaping complacently over huge gaps in our
+memory and linking on conscious experience with conscious experience,
+involves an illusory sense of continuity, and so far of personal
+identity. Thus, our ordinary image of our past life, if only by omitting
+the very large fraction passed in sleep, in at least an approximately
+unconscious state, clearly contains an ingredient of illusion.[132]
+
+It is to be added that the numerous falsifications of our past history,
+which our retrospective imagination is capable of perpetrating, make our
+representation of ourselves at different moments and in different stages
+of our past history to a considerable extent illusory. Thus, though to
+mistake a past dream-experience for a waking one may not be to lose or
+confuse the sense of identity, since our dreams are, after all, a part
+of our experience, yet to imagine that we have ourselves seen what we
+have only heard from another or read is clearly to confuse the
+boundaries of our identity. And with respect to longer sections of our
+history, it is plain that when we wrongly assimilate our remote to our
+present self, and clothe our childish nature with the feelings and the
+ideas of our adult life, we identify ourselves overmuch. In this way,
+through the corruption of our memory, a kind of sham self gets mixed up
+with the real self, so that we cannot, strictly speaking, be sure that
+when we project a mnemonic image into the remote past we are not really
+running away from our true personality.
+
+So far I have been touching only on slight errors in the recognition of
+that identical self which is represented as persisting through all the
+fluctuations of conscious life. Other and grosser illusions connected
+with personal identity are also found to be closely related to defects
+or disturbances of the ordinary mnemonic process, and so can be best
+treated here. In order to understand these, we must inquire a little
+into the nature of our idea and consciousness of a persistent self.
+Here, again, I would remind the reader that I am treating the point only
+so far as it can be treated scientifically or empirically, that is to
+say, by examining what concrete facts or data of experience are taken up
+into the idea of self. I do not wish to foreclose the philosophic
+question whether anything more than this empirical content is involved
+in the conception.
+
+My idea of myself as persisting appears to be built up of certain
+similarities in the succession of my experiences. Thus, my permanent
+self consists, on the bodily side, of a continually renewable perception
+of my own organism, which perception is mainly visual and tactual, and
+which remains pretty constant within certain limits of time. With this
+objective similarity is closely conjoined a subjective similarity. Thus,
+the same sensibilities continue to characterize the various parts of my
+organism. Similarly, there are the higher intellectual, emotional, and
+moral peculiarities and dispositions. My idea of my persistent self is
+essentially a collective image representing a relatively unchanging
+material object, endowed with unchanging sensibilities and forming a
+kind of support for permanent higher mental attributes.
+
+The construction of this idea of an enduring unchanging ego is rendered
+very much easier by the fact that certain concrete feelings are
+approximately constant elements in our mental life. Among these must be
+ranked first that dimly discriminated mass of organic sensation which in
+average states of health is fairly constant, and which stands in sharp
+contrast to the fluctuating external sensations. These feelings enter
+into and profoundly colour each person's mental image of himself. In
+addition to this, there are the frequently recurring higher feelings,
+the dominant passions and ideas which approximate more or less closely
+to constant factors of our conscious experience.
+
+This total image of the ego becomes defined and rendered precise by a
+number of distinctions, as that between my own body or that particular
+material object with which are intimately united all my feelings, and
+other material objects in general; then between my organism and other
+human organisms, with which I learn to connect certain feelings
+answering to my own, but only faintly represented instead of actually
+realized feelings. To these prime distinctions are added others, hardly
+less fundamental, as those between my individual bodily appearance and
+that of other living bodies, between my personal and characteristic
+modes of feeling and thinking and those of others, and so on.
+
+Our sense of personal identity may be said to be rooted in that special
+side of the mnemonic process which consists in the linking of all
+sequent events together by means of a thread of common consciousness. It
+is closely connected with that smooth, gliding movement of imagination
+which appears to involve some more or less distinct consciousness of the
+uniting thread of similarity. And so long as this movement is possible,
+so long, that is to say, as retrospective imagination detects the common
+element, which we may specifically call the recurring consciousness of
+self, so long is there the undisturbed assurance of personal identity.
+Nay, more, even when such a recognition might seem to be difficult, if
+not impossible, as in linking together the very unlike selves, viewed
+both on their objective and subjective sides, of childhood, youth, and
+mature life, the mind manages, as we have seen, to feign to itself a
+sufficient amount of such similarity.
+
+But this process of linking stage to stage, of discerning the common or
+the recurring amid the changing and the evanescent, has its limits.
+Every great and sudden change in our experience tends, momentarily at
+least, to hinder the smooth reflux of imagination. It makes too sharp a
+break in our conscious life, so that imagination is incapable of
+spanning the gap and realizing the then and the now as parts of a
+connected continuous tissue.[133]
+
+These changes may be either objective or subjective. Any sudden
+alteration of our bodily appearance sensibly impedes the movement of
+imagination. A patient after a fever, when he first looks in the glass,
+exclaims, "I don't know myself." More commonly the bodily changes which
+affect the consciousness of an enduring self are such as involve
+considerable alterations of coenaesthesis, or the mass of stable
+organic sensation. Thus, the loss of a limb, by cutting off a portion of
+the old sensations through which the organism may be said to be
+immediately felt, and by introducing new and unfamiliar feelings, will
+distinctly give a shock to our consciousness of self.
+
+Purely subjective changes, too, or, to speak correctly, such as are
+known subjectively only, will suffice to disturb the sense of personal
+unity. Any great moral shock, involving something like a revolution in
+our recurring emotional experience, seems at the moment to rupture the
+bond of identity. And even some time after, as I have already remarked,
+such cataclysms in our mental geology lead to the imaginative thrusting
+of the old personality away from the new one under the form of a "dead
+self."[134]
+
+We see, then, that the failure of our ordinary assurance of personal
+identity is due to the recognition of difference without similarity. It
+arises from an act of memory--for the mind must still be able to recall
+the past, dimly at least--but from a memory which misses its habitual
+support in a recognized element of constancy. If there is no memory,
+that is to say, if the past is a complete blank, the mind simply feels a
+rupture of identity without any transformation of self. This is our
+condition on awaking from a perfectly forgotten period of sleep, or from
+a perfectly unconscious state (if such is possible) when induced by
+anaesthetics. Such gaps are, as we have seen, easily filled up, and the
+sense of identity restored by a kind of retrospective "skipping." On the
+other hand, the confusion which arises from too great and violent a
+transformation of our _remembered_ experiences is much less easily
+corrected. As long as the recollection of the old feelings remains, and
+with this the sense of violent contrast between the old and the new
+ones, so long will the illusion of two sundered selves tend to recur.
+
+The full development of this process of imaginative fission or cleavage
+of self is to be met with in mental disease. The beginnings of such
+disease, accompanied as they commonly are with disturbances of bodily
+sensations and the recurring emotions, illustrate in a very interesting
+way the dependence of the recognition of self on a certain degree of
+uniformity in the contents of consciousness. The patient, when first
+aware of these changes, is perplexed, and often regards the new feelings
+as making up another self, a foreign _Tu_, as distinguished from the
+familiar _Ego_. And sometimes he expresses the relation between the old
+and the new self in fantastic ways, as when he imagines the former to be
+under the power of some foreign personality.
+
+When the change is complete, the patient is apt to think of his former
+self as detached from his present, and of his previous life as a kind of
+unreal dream; and this fading away of the past into shadowy unreal forms
+has, as its result, a curious aberration in the sense of time. Thus, it
+is said that a patient, after being in an asylum only one day, will
+declare that he has been there a year, five years, and even ten
+years.[135] This confusion as to self naturally becomes the
+starting-point of illusions of perception; the transformation of self
+seeming to require as its logical correlative (for there is a crude
+logic even in mental disease) a transformation of the environment. When
+the disease is fully developed under the particular form of monomania,
+the recollection of the former normal self commonly disappears
+altogether, or fades away into a dim image of some perfectly separate
+personality. A new ego is now fully substituted for the old. In other
+and more violent forms of disease (dementia) the power of connecting the
+past and present may disappear altogether, and nothing but the _disjecta
+membra_ of an ego remain.
+
+       *       *       *       *       *
+
+Enough has, perhaps, been said to show how much of uncertainty and of
+self-deception enters into the processes of memory. This much-esteemed
+faculty, valuable and indispensable though it certainly is, can clearly
+lay no claim to that absolute infallibility which is sometimes said to
+belong to it. Our individual recollection, left to itself, is liable to
+a number of illusions even with regard to fairly recent events, and in
+the case of remote ones it may be said to err habitually and uniformly
+in a greater or less degree. To speak plainly, we can never be certain
+on the ground of our personal recollection alone that a distant event
+happened exactly in the way and at the time that we suppose. Nor does
+there seem to be any simple way by mere reflection on the contents of
+our memory of distinguishing what kinds of recollection are likely to be
+illusory.
+
+How, then, it may be asked, can we ever be certain that we are
+faithfully recalling the actual events of the past? Given a fairly good,
+that is, a cultivated memory, it may be said that in the case of very
+recent events a man may feel certain that, when the conditions of
+careful attention at the time to what really happened were present, a
+distinct recollection is substantially correct. Also it is obvious that
+with respect to all repeated experiences our memories afford practically
+safe guides. When memory becomes the basis of some item of generalized
+knowledge, as, for example, of the truth that the pain of indigestion
+has followed a too copious indulgence in rich food, there is little room
+for an error of memory properly so called. On the other hand, when an
+event is not repeated in our experience, but forms a unique link in our
+personal history, the chances of error increase with the distance of the
+event; and here the best of us will do well to have resort to a process
+of verification or, if necessary, of correction.
+
+In order thus to verify the utterances of memory, we must look beyond
+our own internal mental states to some external facts. Thus, the
+recollections of our early life may often be tested by letters written
+by ourselves or our friends at the time, by diaries, and so on. When
+there is no unerring objective record to be found, we may have recourse
+to the less satisfactory method of comparing our recollections with
+those of others. By so doing we may reach a rough average recollection
+which shall at least be free from any individual error corresponding to
+that of personal equation in perception. But even thus we cannot be sure
+of eliminating all error, since there may be a cause of illusion acting
+on all our minds alike, as, for example, the extraordinary nature of the
+occurrence, which would pretty certainly lead to a common exaggeration
+of its magnitude, etc., and since, moreover, this process of comparing
+recollections affords an opportunity for that reading back a present
+preconception into the past to which reference has already been made.
+
+The result of our inquiry is less alarming than it looks at first sight.
+Knowledge is valuable for action, and error is chiefly hurtful in so far
+as it misdirects conduct. Now, in a general way, we do not need to act
+upon a recollection of single remote events; our conduct is sufficiently
+shaped by an accurate recollection of single recent events, together
+with those bundles of recollections of recurring events and sequences of
+events which constitute our knowledge of ourselves and our common
+knowledge of the world about us. Nature has done commendably well in
+endowing us with the means of cultivating our memories up to this point,
+and we ought not to blame her for not giving us powers which would only
+very rarely prove of any appreciable practical service to us.
+
+
+
+
+NOTE.
+
+MOMENTARY ILLUSIONS OF SELF-CONSCIOUSNESS.
+
+
+The account of the apparent ruptures in our personal identity given in
+this chapter may help us to understand the strange tendency to confuse
+self with other objects which occasionally appears in waking
+consciousness and in dreams. These errors may be said generally to be
+due to the breaking up of the composite image of self into its
+fragments, and the regarding of certain of these only. Thus, the
+momentary occurrence of partial illusion in intense sympathy with
+others, including that imaginative projection of self into inanimate
+objects, to which reference has already been made, may be said to depend
+on exclusive attention to the subjective aspect of self, to the total
+disregard of the objective aspect. In other words, when we thus
+momentarily "lose ourselves," or merge our own existence in that of
+another object, we clearly let drop out of sight the visual
+representation of our own individual organism. On the other hand, when
+in dreams we double our personality, or represent to ourselves an
+external self which becomes the object of visual perception, it is
+probably because we isolate in imagination the objective aspect of our
+personality from the other and subjective aspect. It is not at all
+unlikely that the several confusions of self touched on in this chapter
+have had something to do with the genesis of the various historical
+theories of a transformed existence, as, for example, the celebrated
+doctrine of metempsychosis.
+
+
+
+
+CHAPTER XI.
+
+ILLUSIONS OF BELIEF.
+
+
+Our knowledge is commonly said to consist of two large
+varieties--Presentative and Representative. Representative knowledge,
+again, falls into two chief divisions. The first of these is Memory,
+which, though not primary or original, like presentative knowledge, is
+still regarded as directly or intuitively certain. The second division
+consists of all other representative knowledge besides memory,
+including, among other varieties, our anticipations of the future, our
+knowledge of others' past experience, and our general knowledge about
+things. There is no one term which exactly hits off this large sphere of
+cognition: I propose to call it Belief. I am aware that this is by no
+means a perfect word for my purpose, since, on the one hand, it suggests
+that every form of this knowledge must be less certain than presentative
+or mnemonic knowledge, which cannot be assumed; and since, on the other
+hand, the word is so useful a one in psychology, for the purpose of
+marking off the subjective fact of assurance in all kinds of cognition.
+Nevertheless, I know not what better one I could select in order to
+make my classification answer as closely as a scientific treatment will
+allow to the deeply fixed distinctions of popular psychology.
+
+It might at first seem as if perception, introspection, and memory must
+exhaust all that is meant by immediate, or self-evident, knowledge, and
+as if what I have here called belief must be uniformly mediate,
+derivate, or inferred knowledge. The apprehension of something now
+present to the mind, externally or internally, and the reapprehension
+through the process of memory of what was once so apprehended, might
+appear to be the whole of what can by any stretch of language be called
+direct cognition of things. This at least would seem to follow from the
+empirical theory of knowledge, which regards perception and memory as
+the ground or logical source of all other forms of knowledge.
+
+And even if we suppose, with some philosophers, that there are certain
+innate principles of knowledge, it seems now to be generally allowed
+that these, apart from the particular facts of experience, are merely
+abstractions; and that they only develop into complete knowledge when
+they receive some empirical content, which must be supplied either by
+present perception or by memory. So that in this case, too, all definite
+concrete knowledge would seem to be either presentative cognition,
+memory, or, lastly, some mode of inference from these.
+
+A little inquiry into the mental operations which I here include under
+the name belief will show, however, that they are by no means uniformly
+process of inference. To take the simplest form of such knowledge,
+anticipation of some personal experience: this may arise quite apart
+from recollection, as a spontaneous projection of a mental image into
+the future. A person may feel "intuitively certain" that something is
+going to happen to him which does not resemble anything in his past
+experience. Not only so; even when the expectation corresponds to a bit
+of past experience, this source of the expectation may, under certain
+circumstances, be altogether lost to view, and the belief assume a
+secondarily automatic or intuitive character. Thus, a man may have first
+entertained a belief in the success of some undertaking as the result of
+a rough process of inference, but afterwards go on trusting when the
+grounds for his confidence are wholly lost sight of.
+
+This much may suffice for the present to show that belief sometimes
+approximates to immediate, or self-evident, conviction. How far this is
+the case will come out in the course of our inquiry into its different
+forms. This being so, it will be needful to include in our present study
+the errors connected with the process of belief in so far as they
+simulate the immediate instantaneous form of illusion.
+
+What I have here called belief may be roughly distinguished into simple
+and compound belief. By a simple belief I mean one which has to do with
+a single event or fact. It includes simple modes of expectation, as well
+as beliefs in single past facts not guaranteed by memory. A compound
+belief, on the other hand, has reference to a number of events or facts.
+Thus, our belief in the continued existence of a particular object, as
+well as our convictions respecting groups or classes of events, must be
+regarded as compound, since they can be shown to include a number of
+simple beliefs.
+
+
+A. _Simple Illusory Belief: Expectation._
+
+It will be well to begin our inquiry by examining the errors connected
+with simple expectations, so far as these come under our definition of
+illusion. And here, following our usual practice, we may set out with a
+very brief account of the nature of the intellectual process in its
+correct form. For this purpose we shall do well to take a complete or
+definite anticipation of an event as our type.[136]
+
+The ability of the mind to move forward, forecasting an order of events
+in time, is clearly very similar to its power of recalling events. Each
+depends on the capability of imagination to represent a sequence of
+events or experiences. The difference between the two processes is that
+in anticipation the imagination setting out from the present traces the
+succession of experiences in their actual order, and not in the reverse
+order. It would thus appear to be a more natural and easy process than
+recollection, and observation bears out this conclusion. Any object
+present to perception which is associated with antecedents and
+consequents with the same degree of cohesion, calls up its consequents
+rather than its antecedents. The spectacle of the rising of the sun
+carries the mind much more forcibly forwards to the advancing morning
+than backwards to the receding night. And there is good reason to
+suppose that in the order of mental development the power of distinctly
+expecting an event precedes that of distinctly recollecting one. Thus,
+in the case of the infant mind, as of the animal intelligence, the
+presence of signs of coming events, as the preparation of food, seems to
+excite distinct and vivid expectation.[137]
+
+As a mode of assurance, expectation is clearly marked off from memory,
+and is not explainable by means of this. It is a fundamentally distinct
+kind of conviction. So far as we are capable of analyzing it, we may say
+that its peculiarity is its essentially active character. To expect a
+thing is to have stirred the active impulses, including the powers of
+attention; it is to be on the alert for it, to have the attention
+already focussed for it, and to begin to rehearse the actions which the
+actual happening of the event--for example, the approach of a welcome
+object--would excite. It thus stands in marked contrast to memory, which
+is a passive attitude of mind, becoming active only when it gives rise
+to the expectation of a recurrence of the event.[138]
+
+And now let us pass to the question whether expectation ever takes the
+form of immediate knowledge. It may, perhaps, be objected that the
+anticipation of something future cannot be knowledge at all in the sense
+in which the perception of something present or the recollection of
+something past is knowledge. But this objection, when examined closely,
+appears to be frivolous. Because the future fact has not yet come into
+the sphere of actual existence, it is none the less the object of a
+perfect assurance.[139]
+
+But, even if it is conceded that expectation is knowledge, the objection
+may still be urged that it cannot be immediate, since it is the very
+nature of expectation to ground itself on memory. I have already hinted
+that this is not the case, and I shall now try to show that what is
+called expectation covers much that is indistinguishable from immediate
+intuitive certainty, and consequently offers room for an illusory form
+of error.
+
+Let us set out with the simplest kind of expectation, the anticipation
+of something about to happen within the region of our personal
+experience, and similar to what has happened before. And let the coming
+of the event be first of all suggested by some present external fact or
+sign. Suppose, for example, that the sky is heavy, the air sultry, and
+that I have a bad headache; I confidently anticipate a thunderstorm. It
+would commonly be said that such an expectation is a kind of inference
+from the past. I remember that these appearances have been followed by a
+thunderstorm very often, and I infer that they will in this new case be
+so followed.
+
+To this, however, it may be replied that in most cases there is no
+conscious going back to the past at all. As I have already remarked,
+anticipation is pretty certainly in advance of memory in early life. And
+even after the habit of passing from the past to the future, from memory
+to expectation, has been formed, the number of the past repetitions of
+experience would prevent the mind's clearly reverting to them. And,
+further, the very force of habit would tend to make the transition from
+memory to expectation more and more rapid, automatic, and unconscious.
+Thus it comes about that all distinctly suggested approaching events
+seem to be expected by a kind of immediate act of belief. The present
+signs call up the representation of the coming event with all the force
+of a direct intuition. At least, it may be said that if a process of
+inference, it is one which has the minimum degree of consciousness.
+
+It might still be urged that the mind passes from the _present_ facts as
+signs, and so still performs a kind of reasoning process. This is, no
+doubt, true, and differentiates expectation from perception, in which
+there is no conscious transition from the presented to the represented.
+Still I take it that this is only a process of reasoning in so far as
+the sign is consciously generalized, and this is certainly not true of
+early expectations, or even of any expectations in a wholly uncultivated
+mind.
+
+For these reasons I think that any errors involved in such an
+anticipation may, without much forcing, be brought under our definition
+of illusion. When due altogether to the immediate force of suggestion in
+a present object or event, and not involving any conscious transition
+from past to future, or from general truth to particular instance, these
+errors appear to me to have more of the character of illusions than of
+that of fallacies.
+
+Much the same thing may be said about the vivid anticipations of a
+familiar kind of experience called up by a clear and consecutive verbal
+suggestion. When a man, even with an apparent air of playfulness, tells
+me that something is going to happen, and gives a consistent consecutive
+account of this, I have an anticipation which is not consciously
+grounded on any past experience of the value of human testimony in
+general, or of this person's testimony in particular, but which is
+instantaneous and quasi-immediate. Consequently, any error connected
+with the mental act approximates to an illusion.
+
+So far I have supposed that the anticipated event is a recurring one,
+that is to say, a kind of experience which has already become familiar
+to us. This, however, holds good only of a very few of our experiences.
+Our life changes as it progresses, both outwardly and inwardly. Many of
+our anticipations, when first formed, involve much more than a
+reproduction of a past experience, namely, a complex act of constructive
+imagination. Our representations of these untried experiences, as, for
+example, those connected with a new set of circumstances, a new social
+condition, a new mode of occupation, and so on, are clearly at the first
+far from simple processes of inference from the past. They are put
+together by the aid of many fragmentary images, restored by distinct
+threads of association, yet by a process so rapid as to appear like an
+intuition. Indeed, the anticipation of such new experiences more often
+resembles an instantaneous imaginative intuition than a process of
+conscious transition from old experiences. In the case of these
+expectations, then, there would clearly seem to be room for illusion
+from the first.
+
+But even supposing that the errors connected with the first formation of
+an expectation cannot strictly be called illusory, we may see that such
+simple expectation will, in certain cases, tend to grow into something
+quite indistinguishable from illusion. I refer to expectations of
+_remote_ events which allow of frequent renewal. Even supposing the
+expectation to have originated from some rational source, as from a
+conscious inference from past experience, or from the acceptance of
+somebody's statement, the very habit of cherishing the anticipation
+tends to invest it with an automatic self-sufficient character. To all
+intents and purposes the prevision becomes intuitive, by which I mean
+that the mind is at the time immediately certain that something is going
+to happen, without needing to fall back on memory or reflection. This
+being so, whenever the initial process of inference or quasi-inference
+happens to have been bad, an illusory expectation may arise. In other
+words, the force of repetition and habit tends to harden what may, in
+its initial form, have resembled a kind of fallacy into an illusion.
+
+And now let us proceed further. When a permanent expectation is thus
+formed, there arises the possibility of processes which favour illusion
+precisely analogous to those which we have studied in the case of
+memory.
+
+In the first place, the habit of imagining a future event is attended
+with a considerable amount of illusion as to time or remoteness. After
+what has been said respecting the conditions of such error in the case
+of memory, a very few words will suffice here.
+
+It is clear, then, in the first place, that the mind will tend to
+shorten any period of future time, and so to antedate, so to speak, a
+given event, in so far as the imagination is able clearly and easily to
+run over its probable experiences. From this it follows that repeated
+forecastings of series of events, by facilitating the imaginative
+process, tend to beget an illusory appearance of contraction in the time
+anticipated. Moreover, since in anticipation so much of each division of
+the future time-line is unknown, it is obviously easy for the expectant
+imagination to skip over long intervals, and so to bring together widely
+remote events.
+
+In addition to this general error, there are more special errors. As in
+the case of recollection, vividness of mental image suggests
+propinquity; and accordingly, all vivid anticipations, to whatever cause
+the vividness may be owing, whether to powerful suggestion on the part
+of external objects, to verbal suggestion, or to spontaneous imagination
+and feeling, are apt to represent their objects as too near.
+
+It follows that an event intensely longed for, in so far as the
+imagination is busy in representing it, will seem to approach the
+present. At the same time, as we have seen, an event much longed for
+commonly appears to be a great while coming, the explanation being that
+there is a continually renewed contradiction between anticipation and
+perception. The self-adjustment of the mind in the attitude of
+expectant attention proves again and again to be vain and futile, and it
+is this fact which brings home to it the slowness of the sequences of
+perceived fact, as compared with the rapidity of the sequences of
+imagination.
+
+When speaking of the retrospective estimate of time, I observed that the
+apparent distance of an event depends on our representation of the
+intervening time-segment. And the same remark applies to the prospective
+estimate. Thus, an occurrence which we expect to happen next week will
+seem specially near if we know little or nothing of the contents of the
+intervening space, for in this case the imagination does not project the
+experience behind a number of other distinctly represented events.
+
+Finally, it is to be remarked that the prospective appreciation of any
+duration will tend to err relatively by way of excess, where the time is
+exceptionally filled out with clearly expected and deeply interesting
+experiences. To the imagination of the child, a holiday, filled with new
+experiences, appears to be boundless.
+
+Thus far I have assumed that the date of the future event is a matter
+which might be known. It is, however, obvious, from the very nature of
+knowledge with respect to the future, that we may sometimes be certain
+of a thing happening to us without knowing with any degree of
+definiteness when it will happen. In the case of these temporally
+undefined expectations, the law already expounded holds good that all
+vividness of representation tends to lend the things represented an
+appearance of approaching events. On the other hand, there are some
+events, such as our own death, which our instinctive feelings tend to
+banish to a region so remote as hardly to be realized at all.
+
+So much with respect to errors in the localizing of future events.
+
+In the second place, a habit of imagining a future event or group of
+events will give play to those forces which tend to transform a mental
+image. In other words, the habitual indulgence of a certain anticipation
+tends to an illusory view, not only of the "when?" but also of the
+"how?" of the future event. These transformations, due to subtle
+processes of emotion and intellect, and reflecting the present habits of
+these, exactly resemble those by which a remembered event becomes
+gradually transformed. Thus, we carry on our present habits of thought
+and feeling into the remote future, foolishly imagining that at a
+distant period of life, or in greatly altered circumstances, we shall
+desire and aim at the same things as now in our existing circumstances.
+In close connection with this forward projection of our present selves,
+there betrays itself a tendency to look on future events as answering to
+our present desires and aspirations. In this way, we are wont to soften,
+beautify, and idealize the future, marking it off from the hard
+matter-of-fact present.
+
+The less like the future experience to our past experience, or the more
+remote the time anticipated, the greater the scope for such imaginative
+transformation. And from this stage of fanciful transformation of a
+future reality to the complete imaginative creation of such a reality,
+the step is but a small one. Here we reach the full development of
+illusory expectation, that which corresponds to hallucination in the
+region of sense-perception.
+
+In order to understand these extreme forms of illusory expectation, it
+will be necessary to say something more about the relation of
+imagination to anticipation in general. There are, I conceive, good
+reasons for saying that any kind of vivid imagination tends to pass into
+a semblance of an expectation of a coming personal experience, or an
+event that is about to happen within the sphere of our own observation.
+It has long been recognized by writers, among whom I may mention Dugald
+Stewart, that to distinctly imagine an event or object is to feel for
+the moment a degree of belief in the corresponding reality. Now, I have
+already said that expectation is probably a more natural and an earlier
+developed state of mind than memory. And so it seems probable that any
+mental image which happens to take hold on the mind, if not recognized
+as one of memory, or as corresponding to a fact in somebody else's
+experience, naturally assumes the form of an expectation of a personal
+experience. The force of the expectation will vary in general as the
+vividness and persistence of the mental image. Moreover, it follows,
+from what has been said, that this force of imagination will determine
+what little time-character we ever give to these wholly ungrounded
+illusions.
+
+We see, then, that any process of spontaneous imagination will tend to
+beget some degree of illusory expectation. And among the agencies by
+which such ungrounded imagination arises, the promptings of feeling play
+the most conspicuous part. A present emotional excitement may give to an
+imaginative anticipation, such as that of the prophetic enthusiast, a
+reality which approximates to that of an actually perceived object. And
+even where this force of excitement is wanting, a gentle impulse of
+feeling may suffice to beget an assurance of a distant reality. The
+unknown recesses of the remote future offer, indeed, the field in which
+the illusory impulses of our emotional nature have their richest
+harvest.
+
+  "Thus, from afar, each dim discover'd scene
+   More pleasing seems than all the past hath been;
+   And every form, that Fancy can repair
+   From dark oblivion, glows divinely there."
+
+The recurring emotions, the ruling aspirations, find objects for
+themselves in this veiled region. Feelings too shy to burst forth in
+unseemly anticipation of the immediate future, modestly satisfy
+themselves with this remote prospect of satisfaction. And thus, there
+arises the half-touching, half-amusing spectacle of men and women
+continually renewing illusory hopes, and continually pushing the date of
+their realization further on as time progresses and brings no actual
+fruition.
+
+So far I have spoken of such expectations as refer to future personal
+experience only. Growing individual experience and the enlargement of
+this by the addition of social experience enable us to frame a number of
+other beliefs more or less similar to the simple expectations just dealt
+with. Thus, for example, I can forecast with confidence events which
+will occur in the lives of others, and which I shall not even witness;
+or again, I may even succeed in dimly descrying events, such as
+political changes or scientific discoveries, which will happen after my
+personal experience is at an end. Once more, I can believe in something
+going on now at some distant and even inaccessible point of the
+universe, and this appears to involve a conditional expectation, and to
+mean that I am certain that I or anybody else would see the phenomenon,
+if we could at this moment be transported to the spot.
+
+All such previsions are supposed to be formed by a process of inference
+from personal experience, including the trustworthiness of testimony.
+Even allowing, however, that this was so in the first stages of the
+belief, it is plain that, by dint of frequent renewal, the expectation
+would soon cease to be a process of inference, and acquire an apparently
+self-evident character. This being so, if the expectation is not
+adequately grounded to start with, it is very likely to develop into an
+illusion. And it is to be added that these permanent anticipations may
+have their origin much more in our own wishes or emotional promptings
+than in fact and experience. The mind undisciplined by scientific
+training is wont to entertain numerous beliefs of this sort respecting
+what is now going on in unvisited parts of the world, or what will
+happen hereafter in the distant future. The remote, and therefore
+obscure, in space and in time has always been the favourite region for
+the projection of pleasant fancies.
+
+Once more, besides these oblique kinds of expectation, I may form other
+seemingly simple beliefs, to which the term expectation seems less
+clearly applicable. Thus, on waking in the morning and finding the
+ground covered with snow, my imagination moves backwards, as in the
+process of memory, and realizes the spectacle of the softly falling
+snow-flakes in the hours of the night. The oral communication of others'
+experience, including the traditions of the race, enables me to set out
+from any present point of time, and reconstruct complex chains of
+experience of vast length lying beyond the bounds of my own personal
+recollection.
+
+I need not here discuss what the exact nature of such beliefs is. J.S.
+Mill identifies them with expectations. Thus, according to him, my
+belief in the nocturnal snowstorm is the assurance that I should have
+seen it had I waited up during the night. So my belief in Cicero's
+oratory resolves itself into the conviction that I should have heard
+Cicero under certain conditions of time and place, which is identical
+with my expectation that I shall hear a certain speaker to-morrow if I
+go to the House of Commons.[140] However this be, the thing to note is
+that such retrospective beliefs, when once formed, tend to approximate
+in character to recollections. This is true even of new beliefs in
+recent events directly made known by present objective consequences or
+signs, as the snowstorm. For in this case there is commonly no conscious
+comparison of the present signs with previously known signs, but merely
+a direct quasi-mnemonic passage of mind from the present fact to its
+antecedent. And it is still more true of long-entertained retrospective
+beliefs. When, for example, the original grounds of an historical
+hypothesis are lost sight of, and after the belief has hardened and
+solidified by time, it comes to look much more like a recollection than
+an expectation. As a matter of fact, we have seen, when studying the
+illusions of memory, that our personal experience does become confused
+with that of others. And one may say that all long-cherished
+retrospective beliefs tend to become assimilated to recollections.
+
+Here then, again, there seems to be room for illusion to arise. Even in
+the case of a recent past event, directly made known by present
+objective signs, the mind is liable to err just as in the case of
+forecasting an immediately approaching event. And such error has all the
+force of an illusion: its contradiction is almost as great a shock as
+that of a recollection. When, for example, I enter my house, and see a
+friend's card lying on the table, I so vividly represent to myself the
+recent call of my friend, that when I learn the card is an old one which
+has accidentally been put on the table, I experience a sense of
+disillusion very similar to that which attends a contradicted
+perception. The early crude stages of physical science abundantly
+illustrate the genesis of such illusions.
+
+It may be added that if there be any feeling present in the mind at the
+time, the barest suggestion of something having happened will suffice to
+produce the immediate assurance. Thus, an angry person is apt to hastily
+accuse another of having done certain things on next to no evidence. The
+love of the marvellous seems to have played a conspicuous part in
+building up and sustaining the fanciful hypotheses which mark the dawn
+of physical science.
+
+Verbal suggestion is a common mode of producing this semblance of a
+recollected event. By means of the narrative style, it vividly suggests
+the idea that the events described belong to the past, and excites the
+imagination to a retrospective construction of them as though they were
+remembered events. Hence the power of works of fiction on the ordinary
+mind. Even when there is no approach to an illusion of perception, or to
+one of memory in the strict sense, the reading of a work of fiction
+begets at the moment a retrospective belief that has a certain
+resemblance to a recollection.
+
+All such illusions as those just illustrated, if not afterwards
+corrected, tend to harden into yet more distinctly "intuitive" errors.
+Thus, for example, one of the crude geological hypotheses, of which Sir
+Charles Lyell tells us,[141] would, by the mere fact of being kept
+before the mind, tend to petrify into a hard fixed belief. And this
+process of hardening is seen strikingly illustrated in the case of
+traditional errors, especially when these fall in with our own emotional
+propensities. Our habitual representations of the remote historical past
+are liable to much the same kind of error as our recollections of early
+personal experience. The wrong statements of others and the promptings
+of our own fancies may lead in the first instance to a filling up of the
+remote past with purely imaginary shapes. Afterwards the particular
+origin of the belief is forgotten, and the assurance assumes the aspect
+of a perfectly intuitive conviction. The hoary traditional myths
+respecting the golden age, and so on, and the persistent errors of
+historians under the sway of a strong emotional bias, illustrate such
+illusions.
+
+So much as to simple illusions of belief, or such as involve single
+representations only. Let us now pass to compound illusions, which
+involve a complex group of representations.
+
+
+B. _Compound Illusory Belief._
+
+A familiar example of a compound belief is the belief in a permanent or
+persistent individual object of a certain character. Such an idea,
+whatever its whole meaning may be--and this is a disputed point in
+philosophy--certainly seems to include a number of particular
+representations, corresponding to direct personal recollections, to the
+recollections of others, and to numerous anticipations of ourselves and
+of others. And if the object be a living creature endowed with feelings,
+our idea of it will contain, in addition to these represented
+perceptions of ourselves or of others, a series of represented insights,
+namely, such as correspond to the inner experience of the being, so far
+as this is known or imagined.
+
+It would thus seem that the idea which we habitually carry about with us
+respecting a complex individual object is a very composite idea. In
+order to see this more fully, let us inquire into what is meant by our
+belief in a person. My idea of a particular friend contains, among other
+things, numbers of vague representations of his habitual modes of
+feeling and acting, and numbers of still more vague expectations of how
+he will or might feel and act in certain circumstances.
+
+Now, it is plain that such a composite idea must have been a very slow
+growth, involving, in certain stages of its formation, numerous
+processes of inference or quasi-inference from the past to the future.
+But in process of time these elements fuse inseparably: the directly
+known and the inferred no longer stand apart in my mind; my whole
+conception of the individual as he has been, is, and will be, seems one
+indivisible cognition; and this cognition is so firmly fixed and
+presents itself so instantaneously to the mind when I think of the
+object, that it has all the appearance of an intuitive conviction.
+
+If this is a fairly accurate description of the structure of these
+compound representations and of their attendant beliefs, it is easy to
+see how many openings for error they cover. To begin with, my
+representation of so complex a thing as a concrete personality must
+always be exceedingly inadequate and fragmentary. I see only a few
+facets of the person's many-sided mind and character. And yet, in
+general, I am not aware of this, but habitually identify my
+representation with the totality of the object.
+
+More than this, a little attention to the process by which these
+compound beliefs arise will disclose the fact that this apparently
+adequate representation of another has arisen in part by other than
+logical processes. If the blending of memory and expectation were simply
+a mingling of facts with correct inferences from these, it might not
+greatly matter; but it is something very different from this. Not only
+has our direct observation of the person been very limited, even that
+which we have been able to see has not been perfectly mirrored in our
+memory. It has already been remarked that recollection is a selective
+process, and this truth is strikingly illustrated in the growth of our
+enduring representations of things. What stamps itself on my memory is
+what surprised me or what deeply interested me at the moment. And then
+there are all the risks of mnemonic illusion to be taken into account as
+well. Thus, my idea of a person, so far even as it is built up on a
+basis of direct personal recollection, is essentially a fragmentary and
+to some extent a misleading representation.
+
+Nor is this all. My habitual idea of a person is a resultant of forces
+of memory conjoined with other forces. Among these are to be reckoned
+the influence of illusory perception or insight, my own and that of
+others. The amount of misinterpretation of the words and actions of a
+single human being during the course of a long acquaintance must be very
+considerable. To these must be added the effect of erroneous single
+expectations and reconstructions of past experiences, in so far as these
+have not been distinctly contradicted and dissipated. All these errors,
+connected with single acts of observing or inferring the feelings and
+doings of another, have their effect in distorting the subsequent total
+representation of the person.
+
+Finally, we must include a more distinct ingredient of active illusion,
+namely, all the complex effects of the activity of imagination as led,
+not by fact and experience, but by feeling and desire. Our permanent
+idea of another reflects all that we have fondly imagined the person
+capable of doing, and thus is made up of an ideal as well as a real
+actually known personality. And this result of spontaneous imagination
+must be taken to include the ideals entertained by others who are likely
+to have influenced us by their beliefs.[142]
+
+Enough has probably been said to show how immensely improbable it is
+that our permanent cognition of so complex an object as a particular
+human being should be at all an accurate representation of the reality,
+how much of the erroneous is certain to get mixed up with the true. And
+this being so, we may say that our apparently simple direct cognition of
+a given person, our assurance of what he is and will continue to be, is
+to some extent illusory.
+
+
+_Illusion of Self-Esteem._
+
+Let us now pass to another case of compound representation, where the
+illusory element is still more striking. I refer to the idea of self
+which each of us habitually carries about with him. Every man's opinion
+of himself, as a whole, is a very complex mental product, in which facts
+known by introspection no doubt play a part, but probably only a very
+subordinate part. It is obvious, from what has been said about the
+structure of our habitual representations of other individuals, that our
+ordinary representation of ourselves will be tinged with that mass of
+error which we have found to be connected with single acts of
+introspection, recollections of past personal experience, and illusory
+single expectations of future personal experiences. How large an opening
+for erroneous conviction here presents itself can only be understood by
+a reference to certain deeply fixed impulses and feelings connected
+with, the very consciousness of self, and favouring what I have marked
+off as active illusion. I shall try to show very briefly that each man's
+intuitive persuasion of his own powers, gifts, or importance--in brief,
+of his own particular value, contains, from the first, a palpable
+ingredient of active illusion.
+
+Most persons, one supposes, have with more or less distinct
+consciousness framed a notion of their own value, if not to the world
+generally, at least to themselves. And this notion, however undefined it
+may be, is held to with a singular tenacity of belief. The greater part
+of mankind, indeed, seem never to entertain the question whether they
+really possess points of excellence. They assume it as a matter
+perfectly self-evident, and appear to believe in their vaguely conceived
+worth on the same immediate testimony of consciousness by which they
+assure themselves of their personal existence. Indeed, the conviction of
+personal consequence may be said to be a constant factor in most men's
+consciousness. However restrained by the rules of polite intercourse, it
+betrays its existence and its energy in innumerable ways. It displays
+itself most triumphantly when the mind is suddenly isolated from other
+minds, when other men unite in heaping neglect and contempt on the
+believer's head. In these moments he proves an almost heroic strength of
+confidence, believing in himself and in his claims to careful
+consideration when all his acquaintance are practically avowing their
+disbelief.
+
+The intensity of this belief in personal value may be observed in very
+different forms. The young woman who, quite independently of others'
+opinion, and even in defiance of it, cherishes a conviction that her
+external attractions have a considerable value; the young man who, in
+the face of general indifference, persists in his habit of voluble talk
+on the supposition that he is conferring on his fellow-creatures the
+fruits of profound wisdom; and the man of years whose opinion of his own
+social importance and moral worth is quite disproportionate to the
+estimation which others form of his claims--these alike illustrate the
+force and pertinacity of the belief.
+
+There are, no doubt, many exceptions to this form of self-appreciation.
+In certain robust minds, but little given to self-reflection, the idea
+of personal value rarely occurs. And then there are timid, sensitive
+natures that betray a tendency to self-distrust of all kinds, and to an
+undue depreciation of personal merit. Yet even here traces of an impulse
+to think well of self will appear to the attentive eye, and one can
+generally recognize that this impulse is only kept down by some other
+stronger force, as, for example, extreme sensitiveness to the judgment
+of others, great conscientiousness, and so on. And however this be, it
+will be allowed that the average man rates himself highly.
+
+It is to be noticed that this persuasion of personal value or excellence
+is, in common, very vague. A man may have a general sense of his own
+importance without in the least being able to say wherein exactly his
+superiority lies. Or, to put it another way, he may have a strong
+conviction that he stands high in the scale of morally deserving
+persons, and yet be unable to define his position more nearly. Commonly,
+the conviction seems to be only definable as an assurance of a
+superlative of which the positive and comparative are suppressed. At
+most, his idea of his moral altitude resolves itself into the
+proposition, "I am a good deal better than Mr. A. or Mr. B." Now, it is
+plain that in these intuitive judgments on his own excellence, the man
+is making an assertion with respect, not only to inner subjective
+feelings which he only can be supposed to know immediately, but also to
+external objective facts which are patent to others, namely, to certain
+active tendencies and capabilities, to the direction of external conduct
+in certain lines.[143] Hence, if the assertion is erroneous, it will be
+in plain contradiction to others' perceptions of his powers or moral
+endowments. And this is what we actually find. A man's self-esteem, in a
+large preponderance of cases, is plainly in excess of others' esteem of
+him. What the man conceives himself to be differs widely from what
+others conceive him to be.
+
+  "Oh wad some power the giftie gie us,
+   To see oursels as others see us!"
+
+Now, whence comes this large and approximately uniform discrepancy
+between our self-esteem and others' esteem of us? By trying to answer
+this question we shall come to understand still better the processes by
+which the most powerful forms of illusion are generated.
+
+It is, I think, a matter of every-day observation that children manifest
+an apparently instinctive disposition to magnify self as soon as the
+vaguest idea of self is reached. It is very hard to define this feeling
+more precisely than by terming it a rudimentary sense of personal
+importance. It may show itself in very different ways, taking now a more
+active form, as an impulse of self-assertion, and a desire to enforce
+one's own will to the suppression of others' wills, and at another time
+wearing the appearance of a passive emotion, an elementary form of
+_amour propre_. And it is this feeling which forms the germ of the
+self-estimation of adults. For in truth all attribution of value
+involves an element of feeling, as respect, and of active desire, and
+the ascription of value to one's self is in its simplest form merely the
+expression of this state of mind.
+
+But how is it, it may be asked, that this feeling shows itself
+instinctively as soon as the idea of self begins to arise in
+consciousness? The answer to this question is to be found, I imagine, in
+the general laws of mental development. All practical judgments like
+that of self-estimation are based on some feeling which is developed
+before it; and, again, the feeling itself is based on some instinctive
+action which, in like manner, is earlier than the feeling. Thus, for
+example, an Englishman's judgment that his native country is of
+paramount value springs out of a long-existent sentiment of patriotism,
+which sentiment again may be regarded as having slowly grown up about
+the half-blindly followed habit of defending and furthering the
+interests of one's nation or tribe. In a similar way, one suspects, the
+feeling of personal worth, with its accompanying judgment, is a product
+of a long process of instinctive action.
+
+What this action is it is scarcely necessary to remind the reader. Every
+living organism strives, or acts as if it consciously strove, to
+maintain its life and promote its well-being. The actions of plants are
+clearly related to the needs of a prosperous existence, individual first
+and serial afterwards. The movements of the lower animals have the same
+end. Thus, on the supposition that man has been slowly evolved from
+lower forms, it is clear that the instinct of self-promotion must be the
+deepest and most ineradicable element of his nature, and it is this
+instinct which directly underlies the rudimentary sentiment of
+self-esteem of which we are now treating.
+
+This instinct will appear, first of all, as the unreflecting organized
+habit of seeking individual good, of aiming at individual happiness, and
+so of pushing on the action of the individual will. This impulse shows
+itself in distinct form as soon as the individual is brought into
+competition with another similarly constituted being. It is the force
+which displays itself in all opposition and hostility, and it tends to
+limit and counteract the gregarious instincts of the race. In the next
+place, as intelligence expands, this instinctive action becomes
+conscious pursuit of an end, and at this stage the thing pursued
+attracts to itself a sentiment. The individual now consciously desires
+his own happiness as contrasted with that of others, knowingly aims at
+enlarging his own sphere of action to the diminution of others' spheres.
+Here we have the nascent sentiment of self-esteem, on which all later
+judgments respecting individual importance are, in part at least,
+founded.
+
+Thus, we see that long before man had arrived at an idea of self there
+had been growing up an emotional predisposition to think well of self.
+And in this way we may understand how it is that this sentiment of
+self-esteem shows itself immediately and instinctively in the child's
+mind as soon as its unfolding consciousness is strong enough to grasp
+the first rough idea of personal existence. Far down, so to speak, below
+the surface of distinct consciousness, in the intricate formation of
+ganglion-cell and nerve-fibre, the connections between the idea of self
+and this emotion of esteem have been slowly woven through long ages of
+animal development.
+
+Here, then, we seem to have the key to the apparently paradoxical fact
+that a man, with all his superior means of studying his own feelings,
+commonly esteems himself, in certain respects at least, less accurately
+than a good external observer would be capable of doing. In forming an
+opinion of ourselves we are exposed to the full force of a powerful
+impulse of feeling. This impulse, acting as a bias, enters more or less
+distinctly into our single acts of introspection, into our attempts to
+recall our past doings, into our insights into the meaning of others'
+words and actions as related to ourselves (forming the natural
+disposition to enjoy flattery), and finally into our wild dreams as to
+our future achievements. It is thus the principal root of that gigantic
+illusion of self-conceit, which has long been recognized by practical
+sense as one of the greatest obstacles to social action; and by art as
+one of the most ludicrous manifestations of human weakness.
+
+If there are all these openings for error in the beliefs we go on
+entertaining respecting individual things, including ourselves, there
+must be a yet larger number of such openings in those still more
+compound beliefs which we habitually hold respecting collections or
+classes of things. A single illusion of perception or of memory may
+suffice to give rise to a wholly illusory belief in a class of objects,
+for example, ghosts. The superstitious beliefs of mankind abundantly
+illustrate this complexity of the sources of error. And in the case of
+our every-day beliefs respecting real classes of objects, these sources
+contribute a considerable quota of error. We may again see this by
+examining our ordinary beliefs respecting our fellow-men.
+
+A moment's consideration will show that our prevailing views respecting
+any section of mankind, say our fellow-countrymen, or mankind at large,
+correspond at best to a very loose process of reasoning. The accidents
+of our personal experience and opportunities of observation, the
+traditions which coloured our first ideas, the influence of our dominant
+feelings in selecting for attention and retention certain aspects of the
+complex object, and in idealizing this object,--these sources of passive
+and active illusion, must, to say the least, have had as much to do with
+our present solidified and seemingly "intuitive" knowledge as anything
+that can be called the exercise of individual judgment and reasoning
+power.
+
+The force of this observation and the proof that such widely generalized
+beliefs are in part illusory, is seen in the fact that men of unlike
+experience and unlike temperament form such utterly dissimilar views of
+the same object. Thus, as Mr. Spencer has shown,[144] in looking at
+things national there may be not only a powerful patriotic bias at work
+in the case of the vulgar Philistine, but also a distinctly
+anti-patriotic bias in the case of the over-fastidious seeker after
+culture. And I need hardly add that the different estimates of mankind
+held with equal assurance by the cynic, the misanthropist, and the
+philanthropic vindicator of his species, illustrate a like diversity of
+the psychological conditions of belief.
+
+Finally, illusion may enter into that still wider collection of beliefs
+which make up our ordinary views of life and the world as a whole. Here
+there reflect themselves in the plainest manner the accidents of our
+individual experience and the peculiar errors to which our intellectual
+and emotional conformation disposes us. The world is for us what we feel
+it to be; and we feel it to be the cause of our particular emotional
+experience. Just as we have found that our environment helps to
+determine our idea of self and personal continuity, so, conversely, our
+inner experience, our remembered or imagined joys and sorrows throw a
+reflection on the outer world, giving it its degree of worth. Hence the
+contradictory, and consequently to some extent at least illusory, views
+of the optimist and the pessimist, "intuitions" which, I have tried to
+show elsewhere, are connected with deeply rooted habits of feeling, and
+are antecedent to all reasoned philosophic systems.
+
+If proof were yet wanted that these wide-embracing beliefs may to some
+extent be illusory, it would be found in the fact that they can be
+distinctly coloured by a temporary mood or mental tone. As I have more
+than once had occasion to remark, a feeling when present tends to colour
+all the ideas of the time. And when out of sorts, moody, and
+discontented, a man is prone to find a large objective cause of his
+dissatisfaction in a world out of joint and not moving to his mind.
+
+It is evident that all the permanent beliefs touched on in this chapter
+must constitute powerful predispositions with respect to any particular
+act of perception, insight, introspection, or recollection. In other
+words, these persistent beliefs, so far as individual or personal, are
+but another name for those fixed habits of mind which, in the case of
+each one of us, constitute our intellectual bias, and the source of the
+error known as personal equation. And it may be added that, just as
+these erroneous beliefs existing in the shape of fixed prejudices
+constitute a bias to new error, so they act as powerful resisting forces
+in relation to new truth and the correction of error.
+
+In comparing these illusions of belief with those of perception and
+memory, we cannot fail to notice their greater compass or range, in
+other words, the greater extent of the region of fact misrepresented.
+Even if they are less forcible and irresistible than these errors, they
+clearly make up for this by the area which they cover.
+
+Another thing to be observed with respect to these comprehensive beliefs
+is that where, as here, so many co-operant conditions are at work, the
+whole amount of common objective agreement is greatly reduced. In other
+words, individual peculiarities of intellectual conformation, emotional
+temperament, and experience have a far wider scope for their influence
+in these beliefs than they have in the case of presentative cognitions.
+At the same time, it is noteworthy that error much more rapidly
+propagates itself here than in the case of our perceptions or
+recollections. As we have seen, these beliefs all include much more than
+the results of the individual's own experience. They offer a large field
+for the influence of personal ascendency, of the contagion of sympathy,
+and of authority and tradition. As a consequence of this, the illusions
+of belief are likely to be far more persistent than those of perception
+or of memory; for not only do they lose that salutary process of
+correction which comparison with the experience of others affords, but
+they may even be strengthened and upheld to some extent by such social
+influences.
+
+And here the question might seem to obtrude itself, whether, in relation
+to such a fluctuating mass of belief as that just reviewed, in which
+there appears to be so little common agreement, we can correctly speak
+of anything as objectively determinable. If illusion and error as a
+whole are defined by a reference to what is commonly held true and
+certain, what, it may be asked, becomes of the so-called illusions of
+belief?
+
+This question will have to be fully dealt with in the following chapter.
+Here it may be sufficient to remark that amid all this apparent
+deviation of belief from a common standard of truth, there is a clear
+tendency to a rational consensus. Thought, by disengaging what is really
+matter of permanent and common cognition, both in the individual and
+still more in the class,[145] and fixing this quantum of common
+cognition in the shape of accurate definitions and universal
+propositions, is ever fighting against and restraining the impulses of
+individual imagination towards dissociation and isolation of belief. And
+this same process of scientific control of belief is ever tending to
+correct widespread traditional forms of error, and to erect a new and
+better standard of common cognition.
+
+This scientific regulation of belief only fails where the experiences
+which underlie the conceptions are individual, variable, and subjective.
+Hence there is no definite common conception of the value of life and of
+the world, just because the estimate of this value must vary with
+individual circumstances, temperament, etc. All that can be looked for
+here in the way of a common standard or norm is a rough average
+estimate. And this common-sense judgment serves practically as a
+sufficient criterion of truth, at least in relation to such extreme
+one-sidedness of view as approaches the abnormal, that is to say, one of
+the two poles of irrational exaltation, or "joy-madness," and abject
+melancholy, which, appear among the phenomena of mental disease.[146]
+
+
+
+
+CHAPTER XII.
+
+RESULTS.
+
+
+The foregoing study of illusions may not improbably have had a
+bewildering effect on the mind of the reader. To keep the mental eye,
+like the bodily eye, for any time intently fixed on one object is apt to
+produce a feeling of giddiness. And in the case of a subject like
+illusion, the effect is enormously increased by the disturbing character
+of the object looked at. Indeed, the first feeling produced by our
+survey of the wide field of illusory error might be expressed pretty
+accurately by the despondent cry of the poet--
+
+  "Alas! it is delusion all:
+   The future cheats us from afar,
+   Nor can we be what we recall,
+   Nor dare we think on what we are."
+
+It must be confessed that our study has tended to bring home to the mind
+the wide range of the illusory and unreal in our intellectual life. In
+sense-perception, in the introspection of the mind's own feelings, in
+the reading of others' feelings, in memory, and finally in belief, we
+have found a large field for illusory cognition. And while illusion has
+thus so great a depth in the individual mind, it has a no less striking
+breadth or extent in the collective human mind. No doubt its grosser
+forms manifest themselves most conspicuously in the undisciplined mind
+of the savage and the rustic; yet even the cultivated mind is by no
+means free from its control. In truth, most of the illusions illustrated
+in this work are such as can be shared in by all classes of mind.
+
+In view of this wide far-reaching area of ascertained error, the mind
+naturally asks, What are the real limits of illusory cognition, and how
+can we be ever sure of having got beyond them? This question leads us on
+to philosophical problems of the greatest consequence, problems which
+can only be very lightly touched in this place. Before approaching
+these, let us look back a little more carefully and gather up our
+results, reflect on the method which we have been unconsciously
+adopting, and inquire how far this scientific mode of procedure will
+take us in determining what is the whole range of illusory cognition.
+
+We have found an ingredient of illusion mixed up with all the popularly
+recognized forms of immediate knowledge. Yet this ingredient is not
+equally conspicuous in all cases. First of all, illusion varies very
+considerably in its degree of force and persistence. Thus, in general, a
+presentative illusion is more coercive than a representative; an
+apparent reality present to the mind is naturally felt to be more
+indubitable than one absent and only represented. On the other hand, a
+representative illusion is often more enduring than a presentative, that
+is to say, less easily found out. It is to be added that a good deal of
+illusion is only partial, there being throughout an under-current of
+rational consciousness, a gentle play of self-criticism, which keeps the
+error from developing into a perfect self-delusion. This remark applies
+not only to the innocent illusions of art, but also to many of our
+every-day illusions, both presentative and representative. In many
+cases, indeed, as, for example, in looking at a reflection in a mirror,
+the illusion is very imperfect, remaining in the nascent stage.
+
+Again, a little attention to the facts here brought together will show
+that the proportion of illusory to real knowledge is far from being the
+same in each class of immediate or quasi-immediate cognition. Thus, with
+respect to the great distinction between presentative and representative
+knowledge, it is to be observed that, in so far as any act of cognition
+is, strictly speaking, presentative, it does not appear to admit of
+error. The illusions of perception are connected with the representative
+side of the process, and are numerous just because this is so extensive.
+On the other hand, in introspection, where the scope of independent
+representation is so limited, the amount of illusion is very
+inconsiderable, and may in practice be disregarded. So again, to take a
+narrower group of illusions, we find that in the recalling of distant
+events the proportion of error is vastly greater than in the recalling
+of near events.
+
+So much as to the extent of illusion as brought to light by our
+preceding study. Let us now glance at the conclusions obtained
+respecting its nature and its causes.
+
+_Causes of Illusion._
+
+Looking at illusion as a whole, and abstracting from the differences of
+mental mechanism in the processes of perception, memory, etc., we may
+say that the _rationale_ or mode of genesis of illusion is very much the
+same throughout. Speaking broadly, one may describe all knowledge as a
+correspondence of representation with fact or experience, or as a stable
+condition of the representation which cannot be disturbed by new
+experiences. It does not matter, for our present purpose, whether the
+fact represented is supposed to be directly present, as in presentative
+cognition; or to be absent, either as something past or future, or
+finally as a "general fact," that is to say, the group of facts (past
+and future) embodied in a universal proposition.[147]
+
+In general this accordance between our representations and facts is
+secured by the laws of our intellectual mechanism. It follows from the
+principles of association that our simple experiences, external and
+internal, will tend to reflect themselves in perception, memory,
+expectation, and general belief, in the very time-connections in which
+they actually occur. To put it briefly, facts which occur together will
+in general be represented together, and they will be the more perfectly
+co-represented in proportion to the frequency of this concurrence.
+
+Illusion, as distinguished from correct knowledge, is, to put it
+broadly, deviation of representation from fact. This is due in part to
+limitations and defects in the intellectual mechanism itself, such as
+the imperfections of the activities of attention, discrimination, and
+comparison, in relation to what is present. Still more is it due to the
+control of our mental processes by association and habit. These forces,
+which are at the very root of intelligence, are also, in a sense, the
+originators of error. Through the accidents of our experience or the
+momentary condition of our reproductive power, representations get
+wrongly grouped with presentations and with one another; wrongly
+grouped, that is to say, according to a perfect or ideal standard,
+namely, that the grouping should always exactly agree with the order of
+experience as a whole, and the force of cohesion be proportionate to the
+number of the conjunctions of this experience.
+
+This great source of error has been so abundantly illustrated under the
+head of Passive Illusions that I need not dwell on it further. It is
+plain that a passive error of perception, or of expectation, is due in
+general to a defective grouping of elements, to a grouping which
+answers, perhaps, to the run of the individual's actual experience, but
+not to a large and complete common experience.[148] Similarly, an
+illusory general belief is plainly a welding together of elements (here
+concepts, answering to innumerable representative images) in
+disagreement with the permanent connections of experience. Even a
+passive illusion of memory, in so far as it involves a rearrangement of
+successive representations, shows the same kind of defect.
+
+In the second place, this incorrect grouping maybe due, not to defects
+in attention and discrimination, combined with insufficiently grounded
+association, but to the independent play of constructive imagination and
+the caprices of feeling. This is illustrated in what I have called
+Active Illusions, whether the excited perceptions and the hallucinations
+of sense, or the fanciful projections of memory or of expectation. Here
+we have a force directly opposed to that of experience. Active illusion
+arises, not through the imperfections of the intellectual mechanism, but
+through a palpable interference with this mechanism. It is a regrouping
+of elements which simulates the form of a suggestion by experience, but
+is, in reality, the outcome of the individual mind's extra-intellectual
+impulses.
+
+We see, then, that, in spite of obvious differences in the form, the
+process in all kinds of immediate cognition is fundamentally identical.
+It is essentially a bringing together of elements, whether similar or
+dissimilar and associated by a link of contiguity, and a viewing of
+these as connected parts, of a whole; it is a process of synthesis. And
+illusion, in all its forms, is bad grouping or carelessly performed
+synthesis. This holds good even of the simplest kinds of error in which
+a presentative element is wrongly classed; and it holds good of those
+more conspicuous errors of perception, memory, expectation, and compound
+belief, in which representations connect themselves in an order not
+perfectly answering to the objective order.
+
+This view of the nature and causes of illusion is clearly capable of
+being expressed in physical language. Bad grouping of psychical elements
+is equivalent to imperfect co-ordination of their physical, that is to
+say, nervous, conditions, imperfect in the evolutionist's sense, as not
+exactly according with external relations. So far as illusions of
+suggestion (passive illusions) are concerned, the error is connected
+with organized tendencies, due to a limited action of experience. On the
+other hand, illusions of preconception (active illusions) usually
+involve no such deeply fixed or permanent organic connections, but
+merely a temporary confluence of nerve-processes.[149] The nature of the
+physical process is best studied in the case of errors of
+sense-perception. Yet we may hypothetically argue that even in the case
+of the most complex errors, as those of memory and of belief, there is
+implied a deviation in the mode of connection of nervous structures
+(whether the connection be permanent or temporary) from the external
+order of facts.
+
+And now we are in a position to see whether illusion is ultimately
+distinguishable from other modes of error, namely, those incident to
+conscious processes of reasoning. It must have been plain to an
+attentive reader throughout our exposition that, in spite of our
+provisional distinction, no sharp line can be drawn between much of
+what, on the surface, looks like immediate knowledge, and consciously
+derived or inferred knowledge. On its objective side, reasoning may be
+roughly defined as a conscious transition of mind from certain facts or
+relations of facts to other facts or relations recognized as similar.
+According to this definition, a fallacy would be a hasty, unwarranted
+transition to new cases not identical with the old. And a good part of
+immediate knowledge is fundamentally the same, only that here, through
+the exceptional force of association and habit, the transition is too
+rapid to be consciously recognized. Consequently, illusion becomes
+identified at bottom with fallacious inference: it may be briefly
+described as collapsed inference. Thus, illusory perception and
+expectation are plainly a hasty transition of mind from old to new, from
+past to present, conjunctions of experience.[150] And, as we have seen,
+an illusory general belief owes its existence to a coalescence of
+representations of known facts or connections with products of
+imagination which simulate the appearance of inferences from these
+facts.
+
+In the case of memory, in so far as it is not aided by reasoning from
+present signs, there seems to be nothing like a movement of inference.
+It is evident, indeed, that memory is involved in and underlies every
+such transition of thought. Illusions of memory illustrate rather a
+process of wrong classing, that is to say, of wrongly identifying the
+present mental image with past fact, which is the initial step in all
+inference. In this way they closely resemble those slight errors of
+perception which are due to erroneous classing of sense-impressions. But
+since the intellectual process involved in assimilating mental elements
+is very similar to that implied in assimilating complex groups of such
+elements, we may say that even in these simple kinds of error there is
+something which resembles a wrong classing of relations, something,
+therefore, which approximates in character to a fallacy.
+
+By help of this brief review of the nature and causes of illusion, we
+see that in general it may be spoken of as deviation of individual from
+common experience. This applies to passive illusion in so far as it
+follows from the accidents of individual experience, and it still more
+obviously applies to active illusion as due to the vagaries of
+individual feeling and constructive imagination. We might, perhaps,
+characterize all illusion as partial view, partial both in the sense of
+being incomplete, and in the other sense of being that to which the mind
+by its peculiar predispositions inclines. This being so, we may very
+roughly describe all illusion as abnormal. Just as hallucination, the
+most signal instance of illusion, is distinctly on the border-land of
+healthy and unhealthy mental life; just as dreams are in the direction
+of such unhealthy mental action; so the lesser illusions of memory and
+so on are abnormal in the sense that they imply a departure from a
+common typical mode of intellectual action.
+
+It is plain, indeed, that this is the position we have been, taking up
+throughout our discussion of illusion. We have assumed that what is
+common and normal is true, or answers to what is objectively real. Thus,
+in dealing with errors of perception, we took for granted that the
+common percept--meaning by this what is permanent in the individual and
+the general experience--is at the same time the true percept. So in
+discussing the illusions of memory we estimated objective time by the
+judgment of the average man, free from individual bias, and apart from
+special circumstances favourable to error. Similarly, in the case of
+belief, true belief was held to be that which men in general, or in the
+long run, or on the average, hold true, as distinguished from what the
+individual under variable and accidental influences holds true. And even
+in the case of introspection we found that true cognition resolved
+itself into a consensus or agreement as to certain psychical facts.
+
+
+_Criterion of Illusion._
+
+Now, it behoves us here to examine this assumption, with the view of
+seeing how far it is perfectly sound. For it may be that what is
+commonly held true does not in all cases strictly answer to the real, in
+which case our idea of illusion would have to be extended so as to
+include certain common beliefs. This question was partly opened up at
+the close of the last chapter. It will be found that the full
+discussion of it carries us beyond the scientific point of view
+altogether. For the present, however, let us see what can be said about
+it from that standpoint of positive science to which we have hitherto
+been keeping.
+
+Now, if by common be meant what has been shared by all minds or the
+majority of minds up to a particular time, a moment's inspection of the
+process of correcting illusion will show that science assumes the
+possibility of a common illusion. In the history of discovery, the first
+assault on an error was the setting up of the individual against the
+society. The men who first dared to say that the sun did not move round
+the earth found to their cost what it was to fly in the face of a
+common, though illusory, perception of the senses.[151]
+
+If, however, by common be understood what is permanently and unshakably
+held true by men in proportion as their minds become enlightened, then
+science certainly does assume the truth of common perception and belief.
+Thus, the progress of the physical sciences may be described as a
+movement towards a new, higher, and more stable consensus of ideas and
+beliefs. In point of fact, the truths accepted by men of science already
+form a body of common belief for those who are supposed by all to have
+the means of testing the value of their convictions. And the same
+applies to the successive improvements in the conceptions of the moral
+sciences, for example, history and psychology. Indeed, the very meaning
+of science appears to be a body of common cognition to which all minds
+converge in proportion to their capabilities and opportunities of
+studying the particular subject-matter concerned.
+
+Not only so, from a strictly scientific point of view it might seem
+possible to prove that common cognition, as defined above, must in
+general be true cognition. I refer here to the now familiar method of
+the evolutionist.
+
+According to this doctrine, which is a scientific method in so far as it
+investigates the historical developments of mind or the order of mental
+phenomena in time, cognition may be viewed as a part of the result of
+the interaction of external agencies and the organism, as an incident of
+the great process of adaptation, physical and psychical, of organism to
+environment. In thus looking at cognition, the evolutionist is making
+the assumption which all science makes, namely, that correct views are
+correspondences between internal (mental) relations and external
+(physical) relations, incorrect views disagreements between these
+relations. From this point of view he may proceed to argue that the
+intellectual processes must tend to conform to external facts. All
+correspondence, he tells us, means fitness to external conditions and
+practical efficiency, all want of correspondence practical incompetence.
+Consequently, those individuals in whom the correspondence was more
+complete and exact would have an advantage in the struggle for existence
+and so tend to be preserved. In this way the process of natural
+selection, by separately adjusting individual representations to
+actualities, would make them converge towards a common meeting-point or
+social standard of true cognition. That is to say, by eliminating or at
+least greatly circumscribing the region of individual illusion, natural
+selection would exclude the possibility of a persistent common illusion.
+
+Not only so, the evolutionist may say that this coincidence between
+common beliefs and true beliefs would be furthered by social as well as
+individual competition. A community has an advantage in the struggle
+with other communities when it is distinguished by the presence of the
+conditions of effective co-operation, such as mutual confidence. Among
+these conditions a body of true knowledge seems to be of the first
+importance, since conjoint action always presupposes common beliefs,
+and, to be effective action, implies that these beliefs are correct.
+Consequently, it may be argued, the forces at work in the action of man
+on man, of society on the individual, in the way of assimilating belief,
+must tend, in the long run, to bring about a coincidence between
+representations and facts. Thus, in another way, natural selection would
+help to adjust our ideas to realities, and to exclude the possibility of
+anything like a permanent common error.
+
+Yet once more, according to Mr. Herbert Spencer, the tendency to
+agreement between our ideas and the environment would be aided by what
+he calls the direct process of adaptation. The exercise of a function
+tends to the development of that function. Thus, our acts of perception
+must become more exact by mere repetition. So, too, the representations
+and concepts growing out of perceptions must tend to approximate to
+external facts by the direct action of the environment on our physical
+and psychical organism; for external relations which are permanent will,
+in the long run, stamp themselves on our nervous and mental structure
+more deeply and indelibly than relations which are variable and
+accidental.
+
+It would seem, from all this, that so long as we are keeping to the
+scientific point of view, that is to say, taking for granted that there
+is something objectively real answering to our perceptions and
+conceptions, the question of the possibility of a universal or
+(permanently) common illusion does not arise. Yet a little more
+reflection will show us that it may arise in a way. So far as the
+logical sufficiency of the social consensus or common belief is accepted
+as scientifically proved, it is open to suspicion on strictly scientific
+grounds. The evolutionist's proof involves one or two assumptions which
+are not exactly true.
+
+In the first place, it is not strictly correct to say that all illusion
+involves a practical unfitness to circumstances. At the close of our
+investigation of particular groups of illusion, for example, those of
+perception and memory, it was pointed out that many of the errors
+reviewed were practically harmless, being either momentary and
+evanescent, or of such a character as not to lead to injurious action.
+And now, by glancing back over the field of illusion as a whole, we may
+see the same thing. The day-dreams in which some people are apt to
+indulge respecting the remote future have little effect on their
+conduct. So, too, a man's general view of the world is often unrelated
+to his daily habits of life. It seems to matter exceedingly little, in
+general, whether a person take up the geocentric or the heliocentric
+conception of the cosmic structure, or even whether he adopt an
+optimistic or pessimistic view of life and its capabilities.
+
+So inadequate, indeed, does the agency of natural selection seem to be
+to eliminate illusion, that it may even be asked whether its tendency
+may not be sometimes to harden and fix rather than to dissolve and
+dissipate illusory ideas and beliefs. It will at once occur to the
+reader that the illusion of self-esteem, discussed in the last chapter,
+may have been highly useful as subserving individual self-preservation.
+In a similar way, it has been suggested by Schopenhauer that the
+illusion of the lover owes its force and historical persistence to its
+paramount utility for the preservation of the species. And to pass from
+a recurring individual to a permanently common belief, it is maintained
+by the same pessimist and his followers that what they regard as the
+illusion of optimism, namely, the idea that human life as a whole is
+good, grows out of the individual's irrational love of life, which is
+only the same instinctive impulse of self-preservation appearing as
+conscious desire. Once more, it has been suggested that the belief in
+free-will, even if illusory, would be preserved by the process of
+evolution, owing to its paramount utility in certain stages of moral
+development. All this seems to show at least the possibility of a kind
+of illusion which would tend to perpetuate itself, and to appear as a
+permanent common belief.
+
+Now, so far as this is the case, so far as illusion is useful or only
+harmless, natural selection cannot, it is plain, be counted on to weed
+it out, keeping it within the narrow limits of the exceptional and
+individual. Natural selection gets rid of what is harmful only, and is
+indifferent to what is practically harmless.
+
+It may, however, still be said that the process of direct adaptation
+must tend to establish such a consensus of true belief. Now, I do not
+wish for a moment to dispute that the growth of intelligence by the
+continual exercise of its functions tends to such a consensus: this is
+assumed to be the case by everybody. What I want to point out is that
+there is no scientific proof of this position.
+
+The correspondence of internal to external relations is obviously
+limited by the modes of action of the environment on the organism,
+consequently by the structure of the organism itself. Scientific men are
+familiar with the idea that there may be forces in the environment which
+are practically inoperative on the organism, there being no
+corresponding mode of sensibility. And even if it be said that our
+present knowledge of the material world, including the doctrine of the
+conservation of energy, enables us to assert that there is no mode of
+force wholly unknown to us, it can still be contended that the
+environment may, for aught we know, be vastly more than the forces of
+which, owing to the nature of our organism, we know it to be composed.
+In short, since, on the evolution theory viewed as a scientific
+doctrine, the real external world does not directly mirror itself in our
+minds, but only indirectly brings our perceptions and representations
+into adjustment by bringing into adjustment the nervous organism with
+which they are somehow connected, it is plain that we cannot be certain
+of adequately apprehending the external reality which is here assumed to
+exist.
+
+Science, then, cannot prove, but must assume the coincidence between
+permanent common intuitions and objective reality. To raise the question
+whether this coincidence is perfect or imperfect, whether all common
+intuitions known to be persistent are true or whether there are any that
+are illusory, is to pass beyond the scientific point of view to another,
+namely, the philosophic. Thus, our study of illusion naturally carries
+us on from scientific to philosophic reflection. Let me try to make this
+still more clear.
+
+
+_Transition to Philosophic View._
+
+All science makes certain assumptions which it never examines. Thus, the
+physicist assumes that when we experience a sensation we are acted on by
+some pre-existing external object which is the cause, or at least one
+condition, of the sensation. While resolving the secondary qualities of
+light, sound, etc., into modes of motion, while representing the object
+very differently from the unscientific mind, he agrees with this in
+holding to the reality of something external, regarding this as
+antecedent to and therefore as independent of the particular mind which
+receives the sense-impression. Again, he assumes the uniformity of
+nature, the universality of the causal relation, and so on.
+
+Similarly, the modern psychologist, when confining himself within the
+limits of positive science, and treating mind phenomenally or
+empirically, or, in other words, tracing the order of mental states in
+time and assigning their conditions, takes for granted much the same as
+physical science does. Thus, as our foregoing analysis of perception
+shows, he assumes that there is an external cause of our sensations,
+that there are material bodies in space, which act on our sense-organs
+and so serve as the condition of our sense-impressions. More than this,
+he regards, in the way that has been illustrated in this work, the
+percept itself, in so far as it is a process in time, as the normal
+result of the action of such external agents on our nerve-structures, in
+other words, as the effect of such action in the case of the healthy and
+perfect nervous organism with the average organized dispositions,
+physical and psychical; in which case he supposes the percept to
+correspond, in certain respects at least, with the external cause as
+made known by physical science. And, on the other hand, he looks on a
+false or illusory percept as arising in another way not involving, as
+its condition, the pre-existence of a corresponding material body or
+physical agent. And in this view of perception, as of other mental
+phenomena, the psychologist clearly takes for granted the principle that
+all mental events conform to the law of causation. Further, he assumes
+that the individual mind is somehow, in a way which it is not his
+province to inquire into, one and the same throughout, and so on.
+
+The doctrine of evolution, too, in so far as scientific--that is, aiming
+at giving an account of the historical and pre-historical developments
+of the collective mind in time--agrees with psychology in making like
+assumptions. Thus, it conceives an external agency (the environment) as
+the cause of our common sensations and perceptions. That is to say, it
+represents the external world as somehow antecedent to, and so
+apparently independent of, the perceptions which are adjusted to it. And
+all this shows that science, while removed from vulgar unenlightened
+opinion, takes sides with popular thought in assuming the truth of
+certain fundamental ideas or so-called intuitive beliefs, into the exact
+meaning of which it does not inquire.
+
+When the meaning of these assumptions is investigated, we pass out of
+the scientific into the philosophic domain. Philosophy has to critically
+investigate the data of popular thought and of science. It has to
+discover exactly what is implied in these fundamental principles. Then
+it has to test their value by erecting a final criterion of truth, by
+probing the structure of cognition to the bottom, and determining the
+proper organ of certain or accurate knowledge; or, to put it another
+way, it has to examine what is meant by reality, whether there is
+anything real independently of the mind, and if so, what. In doing this
+it inquires not only what common sense means by its object-world clothed
+in its variegated garment of secondary qualities, its beauty, and so on,
+but also what physical science means by its cosmic mechanism of sensible
+and extra-sensible matter in motion: whether there is any kind of
+objective reality belonging to the latter which does not also belong to
+the former; and how the two worlds are related one to another. That is
+to say, he asks whether the bodies in space assumed to exist by the
+physicist as the antecedent conditions of particular sensations and
+percepts are independent of mind and perception generally.[152]
+
+In doing all this, philosophy is theoretically free to upset as much of
+popular belief of the persistent kind as it likes. Nor can science find
+fault with it so long as it keeps to its own sphere, and does not
+directly contradict any truth which science, by the methods proper to
+it, is able to establish. Thus, for example, if philosophy finds that
+there is nothing real independently of mind, science will be satisfied
+so long as it finds a meaning for its assumed entities, such as space,
+external things, and physical causes.[153]
+
+The student of philosophy need not be told that these imposing-looking
+problems respecting cognition, making, up what the Germans call the
+"Theory of Cognition," and the cognate problem respecting the nature of
+reality, are still a long way from being settled. To-day, as in the days
+of Plato and Aristotle, are argued, in slightly altered forms, the vexed
+questions, What is true cognition? Is it a mere efflux from sensation,
+a passive conformity of representation to sensation (sensualism or
+empiricism)? or is it, on the other hand, a construction of active
+thought, involving certain necessary forms of intelligence (rationalism
+or intuitivism)?
+
+Again, how are we to shape to ourselves real objective existence? Is it
+something wholly independent of the mind (realism)? and if so, is this
+known to be what we--meaning here common people and men of science
+alike--represent it as being (natural realism), or something different
+(transfigured realism)? Or is it, on the contrary, something involving
+mind (idealism)? and if so, is it a strictly phenomenal distinction
+within our conscious experience (empirical idealism, phenomenalism), or
+one of the two poles of subject and object constituted by every act of
+thought (rational idealism)? These are some of the questions in
+philosophy which still await their final answer.
+
+Philosophy being thus still a question and not a solution, we need not
+here trouble ourselves about its problems further than to remark on
+their close connection with our special subject, the study of illusion.
+
+Our brief reference to some of the principal inquiries of philosophy
+shows that it tends to throw doubt on things which the unreflecting
+popular mind holds to be indubitable. Different schools of philosophy
+have shown themselves unequally concerned about these so-called
+intuitive certainties. In general it may be said that philosophy,
+though, as I have remarked, theoretically free to set up its own
+standard of certainty, has in practice endeavoured to give a meaning
+to, and to find a justification for the assumptions or first principles
+of science. On the other hand, it has not hesitated, when occasion
+required, to make very light of the intuitive beliefs of the popular
+mind as interpreted by itself. Thus, rationalists of the Platonic type
+have not shrunk from pronouncing individual impressions and objects
+illusory, an assertion which certainly seems to be opposed to the
+assumptions of common sense, if not to those of science. On the other
+hand, the modern empirical or association school is quite ready to
+declare that the vulgar belief in an external world, so far as it
+represents this as independent of mind,[154] is an illusion; that the
+so-called necessary beliefs respecting identity, uniformity, causation,
+etc., are not, strictly speaking, necessary; and so on. And in these
+ways it certainly seems to come into conflict with popular convictions,
+or intuitive certainties, as they present themselves to the unreflecting
+intelligence.
+
+Philosophy seems, then, to be a continuation of that process of
+detecting illusion with which science in part concerns itself. Indeed,
+it is evident that our special study has a very close connection with
+the philosophic inquiry. What philosophy wants is something intuitively
+certain as its starting-point, some _point d'appui_ for its
+construction. The errors incident to the process of reasoning do not
+greatly trouble it, since these can, in general, be guarded against by
+the rules of logic. But error in the midst of what, on the face of it,
+looks like intuitive knowledge naturally raises the question, Is there
+any kind of absolutely certain cognition, any organ for the accurate
+perception of truth? And this intimate relation between the scientific
+and the philosophic consideration of illusion is abundantly illustrated
+in the history of philosophy. The errors of sense, appearing in a region
+which to the vulgar seems so indubitable, have again and again set men
+thinking on the question, "What is the whole range of illusion? Is
+perception, as popularly understood, after all, a big hallucination? Is
+our life a dream?"[155]
+
+On the other hand, if our study of the wide range of illusion is fitted
+to induce that temper of mind which is said to be the beginning of
+philosophy, that attitude of universal doubt expressed by Descartes in
+his famous maxim, _De omnibus dubitandum_, a consideration of the
+process of correction is fitted to lead the mind on to the determination
+of the conditions of accurate knowledge. It is evident, indeed, that the
+very conception of an illusion implies a criterion of certainty: to call
+a thing illusory, is to judge it by reference to some accepted standard
+of truth.
+
+The mental processes involved in detecting, resisting, and overcoming
+illusion, are a very interesting subject for the psychologist, though we
+have not space here to investigate them fully. Turning to presentative,
+and more particularly sense-illusions, we find that the detection of an
+illusion takes place now by an appeal from one sense to another, for
+example, from sight to touch, by way of verification;[156] now (as in
+Myer's experiment) by a reference from sense and presentation altogether
+to representation or remembered experience and a process of reasoning;
+and now, (as in the illusions of art) conversely, by a transition of
+mind from what is suggested to the actual sense-impression of the
+moment. In the sphere of memory, again, illusion is determined, as such,
+now by attending more carefully to the contents of memory, now by a
+process of reasoning from some presentative cognition. Finally, errors
+in our comprehensive general representations of things are known to be
+such partly by reasoning from other conceptions, and partly by a
+continual process of reduction of representation to presentation, the
+general to the particular. I may add that the correction of illusion by
+an act of reflection and reasoning, which brings the part into
+consistent relation with the whole of experience, includes throughout
+the comparison of the individual with the collective or social
+experience.[157]
+
+We may, perhaps, roughly summarize these operations by saying that they
+consist in the control of the lower automatic processes (association or
+suggestion) by the higher activities of conscious will. This activity of
+will takes the form now of an effort of attention to what is directly
+present to the mind (sense-impression, internal feeling, mnemonic image,
+etc.), now of conscious reflection, judgment, and reasoning, by which
+the error is brought into relation to our experience as a whole,
+individual and collective.
+
+It is for the philosopher to investigate the inmost nature of these
+operations as they exhibit themselves in our every-day individual
+experience, and in the large intellectual movements of history. In no
+better way can he arrive at what common sense and science regard as
+certain cognition, at the kinds of knowledge on which they are wont to
+rely most unhesitatingly.
+
+There is one other relation of our subject to philosophic problems which
+I have purposely left for final consideration. Our study has consisted
+mainly in the psychological analysis of illusions supposed to be known
+or capable of being known as such. Now, the modern association school
+professes to be able to resolve some of the so-called intuitions of
+common sense into elements exactly similar to those into which we have
+here been resolving what are acknowledged by all as illusions. This fact
+would seem to point to a close connection between the scientific study
+of illusion and the particular view of these fundamental intuitions
+taken by one philosophic school. In order to see whether there is really
+this connection, we must reflect a little further on the nature of the
+method which we have been pursuing.
+
+I have already had occasion to rise the expression "scientific
+psychology," or psychology as a positive science, and the meaning of
+this expression must now be more carefully considered. As a positive
+science, psychology is limited to the function of analyzing mental
+states, and of tracing their origin in previous and more simple mental
+states. It has, strictly speaking, nothing to do with the question of
+the legitimacy or validity of any mental act.
+
+Take a percept, for example. Psychology can trace its parentage in
+sensation, the mode in which it has come by its contents in the laws of
+association. But by common consent, a percept implies a presentative
+apprehension of an object now present to sense. Is this valid or
+illusory? This question psychology, as science, does not attempt to
+answer. It would not, I conceive, answer it even if it were able to make
+out that the whole mental content in the percept can be traced back to
+elementary sensations and their combinations. For the fact that in the
+chemistry of mind elements may combine in perfectly new forms does not
+disprove that the forms thus arising, whether sentiments or
+quasi-cognitions, are invalid. Much less can psychology dispute the
+validity of a percept if it cannot be sure that the mind adds nothing to
+sensation and its grouping; that in the genesis of the perceptive state,
+with its intuition of something external and now present as object,
+nothing like a form of intelligence is superimposed on the elements of
+sensation, giving to the result of their coalescence the particular
+unity which we find. Whether psychology as a positive science can ever
+be sure of this: whether, that is to say, it can answer the question,
+"How do we come by the idea of object?" without assuming some particular
+philosophic or extra-scientific theory respecting the ultimate nature of
+mind, is a point which I purposely leave open.
+
+I would contend, then, that the psychologist, in tracing the genesis of
+the percept out of previous mental experiences, no more settles the
+question, What is the object of perception? than the physicist settles
+it in referring the sense-impression (and so the percept) to a present
+material agent as its condition.
+
+The same applies to our idea of self. I may discover the concrete
+experiences which supply the filling in of the idea, and yet not settle
+the question, Does intelligence add anything in the construction of the
+form of this idea? and still less settle the question whether there is
+any real unity answering to the idea.
+
+If this is a correct distinction, if psychology, as science, does not
+determine questions of validity or objective meaning but only of
+genesis, if it looks at mental states in relation only to their temporal
+and causal concomitants and not to their objects, it must follow that
+our preceding analysis of illusion involves no particular philosophic
+theory as to the nature of intelligence, but, so far as accurate,
+consists of scientific facts which all philosophic theories of
+intelligence must alike be prepared to accept. And I have little doubt
+that each of the two great opposed doctrines, the intuitive and the
+associational, would claim to be in a position to take up these facts
+into its particular theory, and to view them in its own way.
+
+But in addition to this scientific psychology, there is another
+so-called psychology, which is, strictly speaking, philosophic. This, I
+need hardly say, is the association philosophy. It proceeds by analyzing
+certain cognitions and sentiments into their elements, and straightway
+declaring that they mean nothing more than these. That is to say, the
+associationist passes from genesis to validity, from the history of a
+conscious state to its objective meaning. Thus, from showing that an
+intuitive belief, say that in causation, is not original (in the
+individual or at least in the race), it goes on to assert that it is not
+a valid immediate cognition at all. Now, I am not concerned here to
+inquire into the logical value of this transition, but simply to point
+out that it is extra-scientific and distinctly philosophic. If logically
+justifiable, it is so because of some plainly _philosophic_ assumption,
+as that made by Hume, namely, that all ideas not derived from
+impressions are to this extent fictitious or illusory.
+
+And now we are in a position to understand the bearing of our scientific
+analysis of acknowledged illusions on the associationist's treatment of
+the alleged illusions of common sense. There is no doubt, I think, that
+some of the so-called intuitions of common sense have points of analogy
+to acknowledged illusions. For example, the conviction in the act of
+perception that something external to the mind and independent of it
+exists, has a certain superficial resemblance to an hallucination of
+sense; and moreover, the associationist seeks to explain it by means of
+these very processes which underlie what is recognized by all as
+sense-illusion.[158] Again, it may be said that our notions of force and
+of a causal nexus in the physical world imply the idea of conscious
+energy as known through our muscular sensations, and so have a
+suspicious resemblance to those anthropomorphic illusions of which I
+have spoken under Illusions of Insight. Once more, the consciousness of
+freedom may, as I have suggested, be viewed as analogous in its form and
+its mode of origin to illusions of introspection. As a last example, it
+may be said that the mind's certain conviction of the innateness of some
+of its ideas resembles those illusions of memory which arise through an
+inability to think ourselves back into a remote past having a type of
+consciousness widely unlike that of the present.
+
+But now, mark the difference. In our scientific analysis of popularly
+known illusions, we had something by which to determine the illusory
+character of the presentation or belief. We had a popularly or
+scientifically accepted standard of certainty, by a reference to which
+we might test the particular _soi-disant_ cognition. But in the case of
+these fundamental beliefs we have no such criterion, except we adopt
+some particular philosophic theory, say that of the associationist
+himself. Hence this similarity in structure and origin cannot in itself
+be said to amount to a proof of equality of logical or objective value.
+Here again it must be remarked that origin, does not carry validity or
+invalidity with it.[159]
+
+We thus come back to our starting-point. While there are close
+relations, psychological and logical, between the scientific study of
+the ascertained facts of illusion and the philosophic determination of
+what is illusory in knowledge as a whole, the two domains must be
+clearly distinguished. On purely scientific ground we cannot answer the
+question, "How far does illusion extend?" The solution of this question
+must be handed over to the philosopher, as one aspect of his problem of
+cognition.
+
+One or two remarks may, perhaps, be hazarded in concluding this account
+of the relation of the scientific to the philosophic problem of
+illusion. Science, as we have seen, takes its stand on a stable
+consensus, a body of commonly accepted belief. And this being so, it
+would seem to follow, that so far as she is allowed to interest herself
+in philosophic questions, she will naturally be disposed to ask, What
+beliefs are shared in by all minds, so far as normal and developed? In
+other words, she will be inclined to look at universality as the main
+thing to be determined in the region of philosophic inquiry. The
+metaphysical sceptic, fond of daring exploits, may break up as many
+accepted ideas as he likes into illusory _debris_, provided only he has
+some bit of reality left to take his stand on. Meanwhile, the scientific
+mind, here agreeing with the practical mind, will ask, "Will the beliefs
+thus said to be capable of being shown to be illusory ever cease to
+exercise their hold on men's minds, including that of the iconoclast
+himself? Is the mode of demonstration of such a kind as to be likely
+ever to materially weaken the common-sense 'intuition'?"
+
+This question would seem to be most directly answerable by an appeal to
+individual testimony. Viewed in this light, it is a question for the
+present, for some few already allege that in their case philosophic
+reasonings exercise an appreciable effect on these beliefs. And so far
+as this is so, the man of scientific temper will feel that there is a
+question for him.
+
+It is evident, however, that the question of the persistence of these
+fundamental beliefs is much more one for the future than for the
+present. The correction of a clearly detected illusion is, as I have
+more than once remarked, a slow process. An illusion such as the
+apparent movement of the sun will persist as a partially developed error
+long after it has been convicted. And it may be that the fundamental
+beliefs here referred to, even if presumably illusory, are destined to
+exercise their spell for long ages yet.
+
+Whether this will be the case or not, whether these intuitive beliefs
+are destined slowly to decay and be dissolved as time rolls on, or
+whether they will retain an eternal youth, is a question which we of
+to-day seem, on a first view of the matter, to have no way of answering
+which does not assume the very point in question--the truth or falsity
+of the belief. This much may, however, be said. The associationist who
+resolves these erroneous intuitions into the play of association, admits
+that the forces at work generating and consolidating the illusory belief
+are constant and permanent forces, and such as are not likely to be less
+effective in the future than they have been in the past. Thus, he
+teaches that the intuition of the single object in the act of perception
+owes its strength to "inseparable association," according to which law
+the ideas of the separate "possibilities of sensation," which are all we
+know of the object, coalesce in the shape of an idea of a single uniting
+substance. He adds, perhaps, that heredity has tended, and will still
+tend, to fix the habit of thus transforming an actual multiplicity into
+an imaginary unity. And in thus arguing, he is allowing that the
+illusion is one which, to say the least of it, it will always be
+exceedingly difficult for reason to dislodge.
+
+In view of this uncertainty, and of the possibility, if not the
+probability, of these beliefs remaining as they have remained, at least
+approximately universal, the man of science will probably be disposed to
+hold himself indifferently to the question. He will be inclined to say,
+"What does it matter whether you call such an apparently permanent
+belief the correlative of a reality or an illusion? Does it make any
+practical difference whether a universal 'intuition,' of which we cannot
+rid ourselves, be described as a uniformly recurring fiction of the
+imagination, or an integral constitutive factor of intelligence? And, in
+considering the historical aspect of the question, does it not come to
+much the same thing whether such permanent mental products be spoken of
+as the attenuated forms or ghostly survivals of more substantial
+primitive illusions (for example, anthropomorphic representations of
+material objects, 'animistic' representations of mind and personality),
+or as the slowly perfected results of intellectual evolution?"
+
+This attitude of the scientific mind towards philosophic problems will
+be confirmed when it is seen that those who seek to resolve stable
+common convictions into illusions are forced, by their very mode of
+demonstration, to allow these intuitions a measure of validity. Thus,
+the ideas of the unity and externality attributed to the object in the
+act of perception are said by the associationist to answer to a matter
+of fact, namely, the permanent coexistence of certain possibilities of
+sensation, and the dependence of the single sensations of the individual
+on the presence of the most permanent of these possibilities, namely,
+those of the active or muscular and passive sensations of touch, which
+are, moreover, by far the most constant for all minds. Similarly, the
+idea of a necessary connection between cause and effect, even if
+illusory in so far as it expresses an _objective_ necessity, is allowed
+to be true as an expression of that uniformity of our experience which
+all scientific progress tends to illustrate more and more distinctly.
+And even the idea of a permanent self, as distinct from particular
+fugitive feelings, is admitted by the associationist to be correct in so
+far as it expresses the fact that mind is "a series of feelings which
+is aware of itself as past and future." In short, these "illusory
+intuitions," by the showing of those who affirm them to be illusory, are
+by no means hallucinations having no real object as their correlative,
+but merely illusions in the narrow sense, and illusions, moreover, in
+which the ratio of truth to error seems to be a large one.
+
+It would thus appear that philosophy tends, after all, to unsettle what
+appear to be permanent convictions of the common mind and the
+presuppositions of science much less than is sometimes imagined. Our
+intuitions of external realities, our indestructible belief in the
+uniformity of nature, in the nexus of cause and effect, and so on, are,
+by the admission of all philosophers, at least partially and
+_relatively_ true; that is to say, true in relation to certain features
+of our common experience. At the worst, they can only be called illusory
+as slightly misrepresenting the exact results of this experience. And
+even so, the misrepresentation must, by the very nature of the case, be
+practically insignificant. And so in full view of the subtleties of
+philosophic speculation, the man of science may still feel justified in
+regarding his standard of truth, a stable consensus of belief, as above
+suspicion.
+
+
++----------------------------------------------------------------------+
+|Transcribers note: In the original some footnotes read 'note[1]'and    |
+|'note[2]'. They have been renumbered to allow readers to refer directly|
+|to the correct footnote.                                               |
++----------------------------------------------------------------------+
+
+
+INDEX.
+
+
+  A.
+
+  Abercrombie, Dr. J, 141, note[82], 278.
+
+  Abnormal life, relation of,
+    to normal, 1, 120, 121, 124, 182, 277, 284, note[132], 336;
+    effects of amputation, 62;
+    modification of sensibility in, 65;
+    gross sense-illusions of, 111, hallucinations of, 118;
+    sense of personal identity in, 289.
+
+  Active, stage in perception, 27;
+    illusion distinguished from passive, 45, 332-334.
+
+  Actor. _See_ Theatre.
+
+  Adaptation, illusion as want of, 124, 188, 339.
+
+  AEsthetic intuition, 213;
+    illusions of, 214.
+
+  After-dreams, 144, 183.
+
+  After-sensation, after-impression, 55, 115.
+
+  Anaesthesia, 65.
+
+  Ancestral experience, results of, 281.
+
+  Animals, recognition of portraits by, 105;
+    expectation of, 298.
+
+  Anthropomorphism, 225, 360.
+
+  Anticipation. _See_ Expectation.
+
+  Apparitions. _See_ Hallucination.
+
+  Aristotle, 130.
+
+  Art, illusions of, 77, 104.
+
+  Artemidoros, 129.
+
+  Association, laws of, in perception, 22;
+    in dreams, 153, 156;
+    link of resemblance in dreams, 159;
+    associative dispositions in dreams, 169;
+    effect of, in insight, 221;
+    inseparable, 359.
+
+  Associationist, views of, 349, 352, 355.
+
+  Attention, involved in perception 21;
+    absence of, in sense-illusion, 39, 87;
+    relation of, to recognition of objects, 90;
+    expectant, 93;
+    attitude of, in dreaming, 137, 172;
+    to internal mental states, 194;
+    absence of, in errors of insight, 228.
+
+  Authority, influence of, in introspection, 210;
+    in belief, 325.
+
+  Autobiography, errors connected with, 276, 280.
+
+  Automatic activity of centres, in hallucinations, 113;
+    in dreams, 136, 151;
+    automatic intellectual processes, 300, 335, 352.
+
+
+  B.
+
+  Baillarger, J., 13, note[1], 113, note[57], 119,
+    notes[64] and [65], 120, note[66].
+
+  Bain, Dr. A., 32, note[12], 117, note[60], 190.
+
+  Beattie, J., 141, note[82].
+
+  Beauty, sentiment of, 206, 213.
+
+  Belief, immediate, 14, 15, 294;
+    simple and compound, 296;
+    illusory forms of, 297;
+    simple expectation, 297;
+    expectation, of extra-personal experiences, 307;
+    retrospective, 309;
+    in persistent objects and persons, 312;
+    self-esteem, 315;
+    representation of classes of things, 322;
+    representations of mankind, 322;
+    representation of life and the world as a whole, 322;
+    as predisposition to error, 324;
+    amount of divergence in, 325;
+    tendency towards convergence in, 326.
+
+  Beneficial, correct knowledge as, 340;
+    illusion as, 342.
+
+  Berkeley, Bishop, 218, 349, note[154].
+
+  Binet, A., 53, note[20].
+
+  Boismont, Brierre de, 11, note[1].
+
+  Boerner, J., 146.
+
+  Braid, James, 186, 187.
+
+  Brewster, Sir D., 42, 73, 81, 116.
+
+  Bruecke, E., 77, note[38].
+
+  Byron, Lord, 116.
+
+
+  C.
+
+  Carpenter, Dr. W.B., 32, note[12], 108, 110, note[56], 186, 231,
+    note[111], 265, note[125], 276.
+
+  Castle-building, as illusory perception, 3, 99.
+
+  Cause, idea of, in science, 344;
+    reality of relation of, 347, 349, 356, 360.
+
+  Change, a condition of conscious life, 252, 287, note[133].
+
+  Childhood, our recollections of, 263, 269.
+
+  Children, curiosity of, 175, 180;
+    estimate of time by, 256;
+    confusion of dream and waking life by, 276;
+    imagination of, 279;
+    self-assertion of, 319;
+    intellectual condition of, 357, note[159].
+
+  Clarke, Dr. E.H., 117.
+
+  Classification, in recognition of sensation, 21;
+    in recognition, of object, 24;
+    in introspective recognition, 193.
+
+  Clifford, Professor W.K., 56, note[24].
+
+  Coalescence, of sensations, 43, 52;
+    of dream-images, 162;
+    of internal feelings, 196;
+    of mnemonic images, 265.
+
+  Coenaesthesis, 41, 99, 145, 286, 288.
+
+  Cognition, immediate or intuitive, 5, 14-16, 294;
+    presentative and representative, 9, 13, 217, 330;
+    nature of, in dreams, 168, 172;
+    nature of, generally, 295, 331;
+    philosophic problems of, 346.
+
+  Colour, external reality of, 8, 37;
+    illusory perception of, 37, 88;
+    subjective complementary colours (colour-contrast), 67, 83.
+
+  Coloured media, objects seen through, 82.
+
+  Common cognition, and truth, 337;
+    genesis and validity of, 353.
+
+  Common experience distinguished from
+    individual, 26, 27, 137, 209, 214, 336, 351;
+    illusion as, 47,325, 337.
+
+  Common sense, intuitions of, 346, 349, 352, 357.
+
+  Complementary colours, 67, 83.
+
+  Concave, apparent conversion of, into convex, 84.
+
+  Conjuror, tricks of, 56, 106.
+
+  Consciousness, veracity of, 192, 205;
+    inspection of phenomena of, 196;
+    of self, 283, 285.
+
+  Consensus, the standard of truth, 7, 8, 211, 325, 338, 357.
+
+  Conservation of energy, 343.
+
+  Construction, rational, in dreams, 170.
+
+  Continuum, the perception of the world as, 52, 56, note[24].
+
+  Correction of illusion, in sense-illusion, 38, 124, 137;
+    dreams, 182;
+    introspection, 210;
+    insight, 229;
+    memory, 291;
+    historical correction 338;
+    intellectual processes involved in, 351.
+
+  Criterion of illusion, 337.
+
+  Cudworth, R., 161
+
+
+  D.
+
+  Deception of the senses, 19;
+    self-deception, 200;
+    conscious deception of others, 222.
+
+  Delboeuf, J., 175, note[97], 235, note[113].
+
+  _Delirium tremens_, 118, note[62].
+
+  Democritus, 130.
+
+  De Quincey, 253, 280.
+
+  Descartes, R., 116, 350.
+
+  Dickens, Charles, 277.
+
+  Direction, illusory sense of, in vision, 66, 71, 73;
+   in hearing, 72, 75.
+
+  Disease. _See_ Abnormal life.
+
+  Dissolution. _See_ Evolution.
+
+  Doubt, starting-point in philosophy, 350.
+
+  Dreams, relation of, to illusions of sense, 18, 130;
+    and waking experience, 127;
+    theories of, 128;
+    physiology of, 131;
+    extent of, in sleep, 132;
+    psychological conditions of, 136;
+    excitants of, 139, 143;
+    exaggeration in, 147;
+    symbolism of, 149;
+    as results of automatic activity of centres, 151;
+    as results of association, 153;
+    structure of, 156;
+    incoherent, 156;
+    coherent, 161;
+    action of feeling in, 164;
+    play of associative dispositions in, 168;
+    co-operation of attention and intelligence in, 172;
+    limits of intelligence in, 180;
+    after-dreams, 183, 274;
+    relation of, to hypnotic condition, 185;
+    experience of, in relation to errors of memory, 273.
+
+
+  E.
+
+  Eccentricity, law of, 59.
+
+  Ego. _See_ Self.
+
+  Emotion, and illusion of perception, 103;
+    and hallucination, 115;
+    and bodily sensations, 150;
+    control of dreams by, 164;
+    introspection of, 199;
+    and illusion of introspection, 203;
+    and aesthetic intuition, 213;
+    and illusion of memory, 270;
+    and illusion of belief, 306, 324;
+    and cognition generally, 357, note[159].
+
+  Empiricism, philosophic, 348.
+
+  _Ennui_, and sense of time, 250.
+
+  Environment, sources of sense-illusion in, 47, 48, 70;
+    view of, in mental disease, 290, 326;
+    view of, in normal life, 323;
+    action of, in assimilating belief, 339.
+
+  Error, immediate and mediate, 6, 334.
+
+  Esquirol, J.E.D., 12, note[2].
+
+  Evolution, relation of, to dissolution, 122;
+    of power of introspection, 209;
+    of power of insight, 230;
+    and self-assertion, 320;
+    evolutionist's view of error, 339;
+    doctrine of, as science, 346.
+
+  Exaggeration, in interpretation of sensations, 65;
+    in dream-interpretation, 147;
+    in memory, 269.
+
+  Expectation, preliminary to perception, 30;
+    and illusory perception, 93, 102, 106;
+    nature of, 295;
+    and memory, 298;
+    of new experience, 301;
+    of remote events, 302;
+    measurement of duration in, 302;
+    action of imagination in, 305;
+    extension of meaning of, 307, 308.
+
+  Experience, effect of, in perception, 22, 68, 85, 86, 91;
+    external and internal, 194, 210;
+    revivals of waking, in dreams, 152;
+    effects of present, on retrospection, 267;
+    anticipation of new, 301.
+
+  External world. _See_ World.
+
+
+  F.
+
+  Fallacy and illusion 6, 335;
+    of testimony, 265.
+
+  Familiarity, sense of, in new objects, 272, 281.
+
+  Fechner, G.T., 51.
+
+  Ferrier, Dr., 32, note[12], 58, note[26].
+
+  Fiction, as producing illusion, 278, 279, 311.
+
+  Fitness. _See_ Adaptation.
+
+  Flattery, _rationale_ of, 200, 222.
+
+  Forgetfulness and illusion, 278, 279, 311.
+
+  Free-will, doctrine of, 207, 342, 356.
+
+  Future. _See_ Expectation.
+
+
+  G.
+
+  Galton, F., 117.
+
+  Ghosts. _See_ Hallucination.
+
+  Goethe, 116, 117, 280 and note[131].
+
+  Griesinger, W., 13, note[2], 63, note[31], 66, note[32], 115, 118,
+    note[62], 119, note[64], 120, note[66], 290, note[135], 327,
+    note[146].
+
+  Gruithuisen, 143, 144.
+
+  Gurney, E., 224, note[109].
+
+
+  H.
+
+  Hall, G.S., 186, note[102].
+
+  Hallucination, and illusion, 11, 109, 111, 112, 121;
+    and subjective sensation, 63, 109, 121;
+    sensory and motor, 66;
+    nervous conditions of, 112-114;
+    incomplete and complete, 113;
+    as having either central or peripheral origin, 113;
+    causes of, classified, 115;
+    in sane condition, 116;
+    in insanity, 118;
+    visual and auditory, 119;
+    dreams regarded as, 139, 151;
+    hypnagogic, 143;
+    after-dreams and ghosts, 183;
+    of memory, 271;
+    relation of, to errors of belief, 322;
+    intuition of external world regarded as, 355.
+
+  Happiness, feeling of, 200.
+
+  Harmful, illusion as, 188, 229, 292, 339.
+
+  Harmless, illusions as, 124, 292, 341.
+
+  Hartley, D., 139, 256, note[124], 279.
+
+  Hearing, as mode of perception, 34, 48;
+    localization of impression in, 60;
+    sense of direction in, 72;
+    activity of, in sleep, 140;
+    and muscular sense, 171.
+
+  Heidenhain, Dr., 186-188.
+
+  Helmholtz, H., 22, 23, note[7], 44, 51, 54 and note[22], 55, note[23],
+    57, 67, note[33], 78, note[39], 80, 85, note[43], 88, 90, 207,
+    note[105].
+
+  Heraclitus, 137.
+
+  Heredity, and illusion of memory, 280;
+    action of, in perpetuating intuition, 359.
+
+  Hering, E., 67, note[33].
+
+  Hodgson, Shadworth H., 347, note[153].
+
+  Holland, Sir H., 277.
+
+  Hood, Thomas, 146.
+
+  Hope, illusory. _See_ Expectation.
+
+  Hoppe, Dr. J.I., 51, 58, note[26].
+
+  Horwicz, A., 145, note[85].
+
+  Hume, D., 355.
+
+  Huxley, Professor T., 119, note[1].
+
+  Hyperaesthesia, 65.
+
+  Hypnotism, 185.
+
+  Hypochondria, 65.
+
+  Hypothesis, as illusory, 310, 311.
+
+
+  I.
+
+  Idealism, 348.
+
+  Identity, cases of mistaken, 267.
+
+  Identity, personal, confusion of, in dreams, 163;
+    consciousness of, 241, 267, 282, 285;
+    illusory forms of, 283;
+    gross disturbances of, in normal life, 287;
+    in abnormal life, 289;
+    momentary confusions of, 293.
+
+  Illusion, definition of, 1;
+    varieties of, 9;
+    extent of, 328;
+    _rationale_ of, 331, 337.
+
+  Image (physical). _See_ Reflection.
+
+  Image (mental), in perception, 22;
+    seat of, 32;
+    in dreams, 138;
+    mnemonic, 236.
+
+  Imagination, play of, in perception, 95, 99;
+    and sense-illusion, 106;
+    nature of, in dreaming, 136, 161;
+    as antecedent of dream, 152, 158;
+    as poetic interpretation of nature, 224;
+    memory corrupted by effect of past, 264, 273, 277;
+    present, creating the semblance of recollection, 267, 271;
+    play of, in expectation, 305;
+    as element of illusion generally, 333.
+
+  Immediate. _See_ Cognition.
+
+  Individual, and common experience, 26, 27, 137, 209, 214, 336;
+    dream-experience as, 44, 68;
+    internal experience as, 209;
+    memory as, 232;
+    belief and truth, 338.
+
+  Inference, and immediate knowledge, 6, 334;
+    in perception, 22, 26, 68;
+    in belief, 295.
+
+  Innate, recollection as, 280;
+    principles, 295, 356.
+
+  Insane, sense-illusions of, 63, 65, 111;
+    hallucinations of, 118;
+    dreaming and state of, 182;
+    mnemonic illusions of, 278, 289;
+    beliefs of, 327.
+
+  Insight, nature of, 217;
+    illusions of, defined, 220;
+    passive illusions of, 220;
+    histrionic illusion, 222;
+    active illusions of, 223;
+    poetic interpretation of nature, 224;
+    value of faculty of, 228.
+
+  Interpretation, in correct perception, 22;
+    of impression and experience, 70;
+    and volition, 95;
+    and fixed habits of mind, 101;
+    and temporary attitude of mind, 102;
+    of sensations in dreams, 137, 147;
+    of internal feelings, 203;
+    of others' feelings, 217;
+    of nature by poet, 225;
+    recollection as, 242.
+
+  Introspection, nature of, 14, 189;
+    illusory forms of, 190;
+    confusion of inner and outer experiences, 194;
+    inaccurate inspection of feelings, 196;
+    presentation and representation confused, 199;
+    feelings and inferences from these, 203;
+    moral self-scrutiny, 204;
+    philosophic, 205;
+    value of, 208.
+
+  Intuition. _See_ Cognition.
+
+  Intuitivism, 348.
+
+
+  J.
+
+  Jackson, Dr. J. Hughlings, 27, note[9], 33, 123, note[67].
+
+  Johnson, Dr., 116.
+
+
+  K.
+
+  _Klang_, as compound sensation, 53.
+
+  Knowledge. _See_ Cognition.
+
+
+  L.
+
+  Language, function of, 195.
+
+  Leibnitz, 133.
+
+  Lelut, L.F., 120, note[66].
+
+  Lessing, G. E., 133, note[73].
+
+  Leuret, 290, note[135].
+
+  Lewes, G.H., 28, 32, note[12], 52, note[30], 62, note[1], 68,
+    note[35], 89, note[45], 115, note[58], 150.
+
+  Life, our estimate of, 323, 326, 327.
+
+  Light, sensation and perception of, 59;
+    effects of reflection and refraction, of, 73;
+    representation, of, in painting, 88, 91;
+    action of, in sleep, 140.
+
+  Localization, as local discrimination of sensations, 52;
+    as localizing of sensations, 59, 60;
+    illusory, 61, 82;
+    in hallucination, 118, 119;
+    in dreaming, 148;
+    of events in time, in memory, 238, 245;
+    in expectation, 304.
+
+  Locke, 133, note[73].
+
+  Lotze, H., 60, note[29].
+
+  Lover, illusion of, 224, 227, 342.
+
+  Luminosity of painting, 88, 91.
+
+  Lustre, as compound sensation, 54.
+
+  Lyell, Sir Charles, 311.
+
+
+  M.
+
+  Magic, arts of, 73.
+
+  Magnitude, apparent, in vision, 75, note[37];
+    perception of, in pictorial art, 88, 91;
+    of time-intervals, 245, 249;
+    recollection of, 268.
+
+  Malebranche, 116.
+
+  Mankind, our views of, 322.
+
+  Matter. _See_ World (material).
+
+  Maudsley, Dr. H., 32, note[12].
+
+  Maury, A., 140, 143, 153, note[92], 159, 163, note[94], 173.
+
+  Mayer, Dr. A., 66, note[32].
+
+  Measurement, subjective, of time, 245.
+
+  Media, coloured, illusions connected with presence of, 82.
+
+  Memory, nature of, 9, 13, 231;
+    veracity of, 232, 290;
+    defined, 234;
+    psychology of, 236;
+    physiology of, 237;
+    localization of events in, 238;
+    and sense of personal identity, 241, 283;
+    illusions of, 241;
+    illusory localization, 245, 256;
+    distortions of, 261;
+    hallucinations of, 271;
+    illusions respecting personal identity, 283;
+    relation of, to belief, 295;
+    compared with expectation, 297;
+    and inference, 335.
+
+  Metempsychosis, 294.
+
+  Meyer, H., 83, 144.
+
+  Mill, J.S., 298, note[138], 309.
+
+  Mirrors, as means of delusion, 73.
+
+  Misanthropist, 2, 323.
+
+  Mitchell, Dr. Weir, 62.
+
+  Monomania, 111.
+
+  Moral, intuition, 216;
+    self-inspection, 204.
+
+  Motor illusions. _See_ Muscular sense.
+
+  Movement, apparent, 50, 57, 73, 81, 95, 107;
+    in dreams, 142, 154.
+
+  Mueller, Johannes, 58, note[27], 100, 117, 143.
+
+  _Muscae volitantes_, 118, note[62].
+
+  Muscular sense, in perception, 23;
+    illusions connected with, 50, 57, 62, 66;
+    co-operation, of, in dreams, 142, 154.
+
+  Music, subjective interpretation of, 223.
+
+
+  N.
+
+  Natural selection, effect of, in eliminating error, 340.
+
+  Nature, personification of, 224;
+    uniformity of, 344, 360.
+
+  Necessity, idea of, 349, 360.
+
+  Nervous system, and conditions of perception, 31;
+    connections of, 32, 169;
+    function of, and force of stimulus, 47, 50;
+    prolonged activity of, 55;
+    specific energy of, 58;
+    variations in state of, 64;
+    fatigue of, 65, 115;
+    disease of, _ibid._;
+    nervous conditions of hallucination, 112, 115;
+    nervous dissolution and evolution, 122;
+    condition of, in sleep, 131;
+    in hypnotic condition, 186;
+    nervous conditions of memory, 237;
+    nervous conditions of illusion in general, 334.
+
+  Normal life, relation of,
+    to abnormal, 1, 121, 124, 182, 277, 284, note[132];
+    hallucinations of, 116.
+
+
+  O.
+
+  Object, nature of, 36, 353.
+
+  Objective and subjective experience, 26, 27, 137, 214.
+
+  Old age, dreams how regarded in, 276.
+
+  Oneirocritics, 129.
+
+  Opera, illusion connected with, 104.
+
+  Optimism, 323, 327, 342.
+
+  Organic sensations, discrimination of, 41;
+    interpretation of, 99;
+    in sleep, 145, 148.
+
+  Organism, conditions of illusion in, 47, 50;
+    relation of our conception of the universe to sensibilities of, 343.
+
+  Orientation, 125, 138.
+
+
+  P.
+
+  Pain, recollection of, 264, 270.
+
+  Painting, representation of third dimension by, 77;
+    apparent movement of eye in portrait, 81;
+    discrepancies between, and object in magnitude and luminosity, 88;
+    realization of, and mental preparation, 105;
+    realization of, by animals, 105.
+
+  Paraesthesia, 68.
+
+  Paralysis of ocular muscles, 66.
+
+  Passive, and active factor in perception, 27;
+    and active illusion, 45.
+
+  Percept, 22;
+    and sense-impression, 59.
+
+  Perception, a form of immediate knowledge, 10, 13, 17, 18;
+    external and internal, 14;
+    philosophy of, 14, 20, 22, 36, 346, 348, 353, 355, 359;
+    illusions of, 19, 35;
+    psychology of, 20;
+    and inference, 22, 26, 76;
+    physiological conditions of, 31.
+
+  Persistent objects, representation of, 312.
+
+  Persistent self. _See_ Personal identity.
+
+  Personal equation, in perception, 101;
+    in aesthetic intuition, 214;
+    in memory, 292;
+    in belief, 324.
+
+  Personal identity, consciousness of, 241, 282, 285;
+    illusions connected with, 283;
+    disturbances in sense of, 287;
+    sense of, in insanity, 289;
+    momentary confusions of, 293;
+    philosophic problem of, 285, 354, 360.
+
+  Personification of nature, 224.
+
+  Perspective, linear, 79, 97, 98;
+    aerial, 80;
+    of memory, 245.
+
+  Pessimism, 323, 327.
+
+  Phenomenalism, 348.
+
+  Philosophy, conception of illusion by, 7, 36, 205, 285, 349;
+    of mind, 132, 285, 344, 348;
+    as theory of knowledge, 295, 346;
+    and science, 346, 348;
+    and common sense, 347, 349;
+    problems of, 347.
+
+  Phosphenes, 58.
+
+  Physical science. _See_ Science.
+
+  Plato, 281.
+
+  Platonists, 349.
+
+  Pleasure, feeling of, 200;
+    recollection of, 264, 270.
+
+  Plutarch, 133, note[73].
+
+  Poetry, lyrical and dreams, 164;
+    misinterpretation of, 223;
+    personification, 224.
+
+  Points, discrimination of, 52.
+
+  Poisons, action of, 115.
+
+  Pollock, F., 184, note[101].
+
+  Pollock, W.H., 184.
+
+  Predisposition, action of, in perception, 44, 101, 102;
+    in aesthetic intuition, 215;
+    in insight, 223;
+    in recollection, 268;
+    in belief, 305, 319;
+    belief as, 324.
+
+  Prejudice. _See_ Predisposition.
+
+  Prenatal experience, recollection of, 281.
+
+  Preperception, 27;
+    illusions connected with, 44, 93;
+    voluntary, 95;
+    result of habit of mind, 101;
+    result of temporary conditions, 102;
+    as sub-expectation, 102;
+    as definite expectation, 106.
+
+  Presentation and representation, 9, 10, 13, 14, 192, 234, 329, 330.
+
+  Projection, outward, of sensations, 63;
+    of mental image, 111, 112;
+    of solid form on flat, 79, 81, 96.
+
+  Prophetic, dreams as, 129, 147, note[88];
+    enthusiast, 307.
+
+  Psychology, popular and scientific, 9, 10;
+    distinguished from philosophy, 14, 36, 345, 352;
+    introspective method of, 208;
+    as a kind of philosophy, 305.
+
+  Public events, localization, of, by memory, 258.
+
+
+  R.
+
+  Radestock, P., 130, note[71], 132, note[72], 134, note[75], 140, 141,
+    149, note[90], 162, 182, 275.
+
+  Rationalism, philosophic, 348.
+
+  Realism, 348.
+
+  Reality, nature of, 36, 346.
+
+  Recognition, and perception, 24, 25;
+    illusions of, 87;
+    and memory, 234.
+
+  Reflection (of light), illusions connected with, 73, 83.
+
+  Refraction and optical illusion, 73.
+
+  Relative, sensation as, 64;
+    attention to magnitude and brightness as, 91;
+    estimate of duration as, 249.
+
+  Relief, illusory perception of, 75, 96.
+
+  Representation and presentation, 9, 10, 13, 14, 192.
+
+  Retrospection. _See_ Memory.
+
+  Ribot, T., 238, note[114], 290, note[135].
+
+  Richter, J.P., 143.
+
+  Robertson, Professor G.C., 35, note[14].
+
+  Romanes, G.J., 105, note[2], 250, note[122].
+
+  Rousseau, 280.
+
+
+  S.
+
+  Savage, dream theory of, 128;
+    idea of nature of, 225.
+
+  Scherner, C.A., 140, 149.
+
+  Schopenhauer, A., 145, 342.
+
+  Schroeder, H., 85.
+
+  Science, philosophy and, 8, 36, 285, 344;
+    conception of the material world in physical, 36, 343, 346, 347;
+    and common cognition, 338, 357.
+
+  Scott, Sir W., 116, 125.
+
+  Secondary qualities, 36, 344.
+
+  Selection, process of, in perception, 95;
+    in dreams, 174;
+    in memory, 257, 263.
+
+  Self, confusion of, in dreams, 163;
+    introspective knowledge of, 192;
+    self-deception, 200;
+    identity of, 241, 282, 285;
+    confusion of present and past, 267, 284;
+    disturbances in recognition of, 287, 289;
+    momentary confusions of, 295;
+    confusion of present and future, 305.
+
+  Self-esteem, illusion of, 315;
+    origin of, 319;
+    utility of, 342.
+
+  Self-preservation, 320.
+
+  Sensation, element in perception, 20;
+    discrimination and classification of, 21;
+    interpretation of, 22;
+    inattention to, 39, 87;
+    modified by central reaction, 39, 87, 89, 91;
+    confusion of novel, 40;
+    indistinct, 41;
+    misinterpretation of, 44;
+    relation of, to stimulus, 46, 50;
+    limits to discrimination of, 52;
+    after-impression, 55;
+    subjective, 59, 62, 107, 143;
+    localization of, 59.
+
+  Sensibility, limits of, 50;
+    variations of, 64.
+
+  Sensualism, philosophic, 348.
+
+  Shadow, cast, 77.
+
+  Shakespeare, 3.
+
+  Sight, mode of perception, 19, 33, 34, 48, 49;
+    local discrimination in, 52;
+    single vision, 54;
+    localization of impression in, 60;
+    in sleep, 139;
+    images of, in sleep, 150, 154.
+
+  Single, vision, 54;
+    touch, 72.
+
+  Sleep, mystery of, 127;
+    physiology of, 131.
+
+  Sleight of hand. _See_ Conjuror.
+
+  Smell, as mode of perception, 34, note[14];
+    localization of impression in, 60;
+    subjective sensations of, 108;
+    in sleep, 141;
+    and taste, 171.
+
+  Solidity, illusory perception of, 75, 96.
+
+  Space, representation of, 207.
+
+  Specific energy of nerves, 58.
+
+  Spectra, ocular, etc. _See_ Subjective sensation.
+
+  Spencer, Herbert, 32, note[12], 128, note[69], 323, 340.
+
+  Spinoza, 143, 184.
+
+  Spiritualist _seances_, 103, 107, 123, 265.
+
+  Stereoscope, 75.
+
+  Stewart, Dugald, 172, 306.
+
+  Stimulus, qualitative relation of, to sensations, 46, 58, 67;
+    quantitative relation of, to sensation, 50, 64;
+    after-effect of, 55;
+    prolonged action of, 56;
+    subjective or internal, 62;
+    exceptional relation of, to organ, 70;
+    action of, in sleep, 135, 139, 143;
+    in hypnotic condition, 186.
+
+  Struempell, L., 144, 147, note[89].
+
+  Subjective, experience, 26, 27, 137, 214;
+    movement, 51, 57;
+    sensation, 59, 62, 107, 113, 121, 143.
+
+  Suggestion, by external circumstances, 30, 44, 89, 91, 267;
+    verbal, 30, 106, 188, 215, 268, 301, 310.
+
+  Symbol, dream as, 129, 149.
+
+  Sympathy, basis of knowledge, 223;
+    and illusion of insight, 223;
+    and illusion of memory, 277;
+    and momentary illusion, 293.
+
+
+  T.
+
+  Taine, H., 60, note[29], 108, note[54], 117, note[59], 137,
+    298, note[137], 356, note[158].
+
+  Taste, aesthetic. _See_ AEsthetic intuition.
+
+  Taste, localization of impression in, 60;
+    subjective sensations of, 63;
+    variations in sensibility, 68;
+    activity of, in sleep, 141;
+    and smell, 171.
+
+  Temperament, a factor in sense-illusion, 101;
+    in dreams, 137;
+    in illusory belief, 325;
+    in illusion generally, 334, note[149].
+
+  Temperature, sense of, 65.
+
+  Tennyson, A., 226.
+
+  Testa, A.J., 131.
+
+  Testimony, of consciousness, 205;
+    fallacies of, 265;
+    to identity, 267.
+
+  Thaumatrope, 56.
+
+  Theatre, illusion of the, 104, 222;
+    self-deception of the actor, 200.
+
+  Thompson, Professor S.P., 51, note[17].
+
+  Thought, in relation to belief, 326.
+
+  Time, retrospective idea of, 239, 246, 250;
+    constant error in estimate of, 245;
+    subjective estimate of, 249;
+    contemporaneous estimate of, 250;
+    sense of, in insanity, 290;
+    prospective estimate of, 303.
+
+  Touch, as form of perception, 33, 34, 49;
+    local discrimination in, 52;
+    subjective sensations of, 62;
+    variations in sensibility of, 65;
+    in sleep, 141.
+
+  Transformation, in perception, 94;
+    of images in dreams, 163;
+    in memory, 262, 267;
+    in expectation, 305.
+
+  Trick. _See_ Conjuror.
+
+  Tuke, Dr., 110.
+
+  Tylor, E.B., 128, note[69].
+
+
+  U.
+
+  Unconscious, inference, 22, 68, 269, 335, note[150];
+    mental activity, 133, 235;
+    impressions, 41, 152.
+
+  Useful. _See_ Beneficial.
+
+
+  V.
+
+  Vanity. _See_ Self-esteem.
+
+  Venn, J., 299, note[139].
+
+  Ventriloquism, 82.
+
+  Verification, of sense-impression, 38, 351;
+    of self-inspection, 210;
+    of memory, 291.
+
+  Verisimilitude, in art, 80, 88;
+    in theatrical representation, 104;
+    in dreams, 168.
+
+  Vierordt, 245.
+
+  Vision. _See_ Sight.
+
+  Visions, 1, 110;
+    dreams regarded as, 128, 131.
+
+  Vital sense. _See_ Coenaesthesis.
+
+  Voice, internal, 119, 194;
+    activity of, in dreams, 155.
+
+  Volition, and perception, 95;
+    absence of, during sleep, 137,172;
+    co-operation of, in correction, of illusion, 352.
+
+  Volkelt, J., 172.
+
+
+  W.
+
+  Weber, E.H., 43.
+
+  Weinhold, Professor, 186.
+
+  Wetness, perception of, 53.
+
+  Wheatstone, Sir C, 75.
+
+  Wheel of life, 56.
+
+  Will. _See_ Volition.
+
+  Wordsworth, W., 281.
+
+  World, our estimate of, 323, 326, 327;
+    scientific conception of material, 8, 36, 343, 344;
+    reality of external, 344-346, 349, 353, 355, 360.
+
+  Wundt, Professor, W. 13, note[2], 31, note[11], 32, note[12], 58,
+    note[27], 67, note[34], 75, 93, note[47], 118, note[63], 136,
+    note[77], 139, 143, 177, 246, 247, note[119], 251, 252, 254.
+
+
+THE END
+
+
+FOOTNOTES:
+
+[1] A history of the distinction is given by Brierre de Boismont, in his
+work _On Illusions_ (translated by R. T. Hulme, 1859). He says that
+Arnold (1806) first defined hallucination, and distinguished it from
+illusion. Esquirol, in his work, _Des Maladies Mentales_ (1838), may be
+said to have fixed the distinction. (See Hunt's translation, 1845, p.
+111.)
+
+[2] This fact has been fully recognized by writers on the pathology of
+the subject; for example, Griesinger, _Mental Pathology and
+Therapeutics_ (London, 1867), p. 84; Baillarger, article, "Des
+Hallucinations," in the _Memoires de l'Academie Royale de Medecine_,
+tom. xii. p. 273, etc; Wundt, _Physiologische Psychologie_, p. 653.
+
+[3] I here touch on the distinction between the psychological and the
+philosophical view of perception, to be brought out more fully
+by-and-by.
+
+[4] It might even be urged that the order here adopted is scientifically
+the best, since sense-perception is the earliest form of knowledge,
+introspected facts being known only in relation to perceived facts. But
+if the mind's knowledge of its own states is thus later in time, it is
+earlier in the logical order, that is to say, it is the most strictly
+presentative form of knowledge.
+
+[5] Here and elsewhere I use the word "impression" for the whole complex
+of sensation which is present at the moment. It may, perhaps, not be
+unnecessary to add that, in employing this term, I am making no
+assumption about the independent existence of external objects.
+
+[6] Psychological usage has now pretty well substituted the term "image"
+for "idea," in order to indicate an individual (as distinguished from a
+general) representation of a sensation or percept. It might, perhaps, be
+desirable to go further in this process of differentiating language, and
+to distinguish between a sensational image, _e.g._ the representation of
+a colour, and a perceptional image, as the representation of a coloured
+object. It may be well to add that, in speaking of a fusion of an image
+and a sensation, I do not mean that the former exists apart for a single
+instant. The term "fusion" is used figuratively to describe the union of
+the two sides or aspects of a complete percept.
+
+[7] This impulse to fill in visual elements not actually present is
+strikingly illustrated in people's difficulty in recognizing the gap in
+the field of vision answering to the insensitive "blind" spot on the
+retina. (See Helmholtz, _Physiologische Optik_, p. 573, _et seq._)
+
+[8] This relation will be more fully discussed under the head of
+"Memory."
+
+[9] I adopt this distinction from Dr. J. Hughlings Jackson. See his
+articles, "On Affections of Speech from Diseases of the Brain," in
+_Brain_, Nos. iii. and vii. The second stage might conveniently be named
+apperception, but for the special philosophical associations of the
+term: _Problems of Life and Mind_, third series, p. 107. This writer
+employs the word "preperception" to denote this effect of previous
+perception.
+
+[10] Such verbal suggestion, moreover, acting through a
+sense-impression, has something of that vividness of effect which
+belongs to all excitation of mental images by external stimuli.
+
+[11] See Wundt, _Physiologische Psychologie_, p. 723.
+
+[12] For a confirmation of the view adopted in the text, see Professor
+Bain, _The Senses and the Intellect_, Part II. ch. i. sec. 8; Herbert
+Spencer, _Principles of Psychology_, vol. i. p. 234, _et passim_; Dr.
+Ferrier, _The Functions of the Brain_, p. 258, _et seq._; Professor
+Wundt, _op. cit._, pp. 644, 645; G. H. Lowes, _Problems of Life and
+Mind_, vol. v. p. 445, _et seq._ For an opposite view, see Dr.
+Carpenter, _Mental Physiology_, fourth edit., p. 220, etc.; Dr.
+Maudsley, _The Physiology of Mind_, ch. v. p. 259, etc.
+
+[13] See note, p. 22.
+
+[14] Touch gives much by way of interpretation only when an individual
+object, for example a man's hat, is recognized by aid of this sense
+alone, in which case the perception distinctly involves the reproduction
+of a complete visual percept. I may add that the organ of smell comes
+next to that of hearing, with respect both to the range and definiteness
+of its simultaneous sensations, and to the amount of information
+furnished by these. A rough sense of distance as well as of direction is
+clearly obtainable by means of this organ. There seems to me no reason
+why an animal endowed with fine olfactory sensibility, and capable of an
+analytic separation of sense elements, should not gain a rough
+perception of an external order much more complete than our auditory
+perception, which is necessarily so fragmentary. This supposition
+appears, indeed, to be the necessary complement to the idea first
+broached, so far as I am aware, by Professor Croom Robertson, that to
+such animals, visual perception consists in a reference to a system of
+muscular feelings defined and bounded by strong olfactory sensations,
+rather than by tactual sensations as in our case.
+
+[15] It may be said, perhaps, that the exceptional direction of
+attention, by giving an unusual intensity to the impression, causes us
+to exaggerate it just as in the case of a novel sensation. An effort of
+attention directed to any of our vague bodily sensations easily leads us
+to magnify its cause. A similar confusion may arise even in direct
+vision, when the objects are looked at in a dim light, through a want of
+proper accommodation. (See Sir D. Brewster, _op. cit._, letter i)
+
+[16] They might also be distinguished as objective and subjective
+illusions, or as illusions _a posteriori_ and illusions _a priori_.
+
+[17] _Die Schein-Bewegungen_, von Professor Dr. J.I. Hoppe (1879); _cf._
+an ingenious article on "Optical Illusions of Motion," by Professor
+Silvanus P. Thompson, in _Brain_, October, 1880. These illusions
+frequently involve the co-operation of some preconception or
+expectation. For example, the apparent movement of a train when we are
+watching it and expecting it to move, involves both an element of
+sense-impression and of imagination. It is possible that the illusion of
+table-turning rests on the same basis, the table-turner being unaware of
+the fact of exerting a certain amount of muscular force, and vividly
+expecting a movement of the object.
+
+[18] _Physiologische Optik_, p. 316.
+
+[19] It is plain that this supposed error could only be brought under
+our definition of illusion by extending the latter, so as to include
+sense-perceptions which are contradicted by reason employing idealized
+elements of sense-impression, which, as Lewes has shown (_Problems of
+Life and Mind_, i. p. 260), make up the "extra-sensible world" of
+science.
+
+[20] An ingenious writer, M. Binet, has tried to prove that the fusion
+of homogeneous sensations, having little difference of local colour, is
+an illustration of this principle. (See the _Revue Philosophique_,
+September, 1880.)
+
+[21] Even the fusion of elementary sensations of colour, on the
+hypothesis of Young and Helmholtz, in a seemingly simple sensation may
+be explained to some extent by these circumstances, more especially the
+identity of local interpretation.
+
+[22] The perception of lustre as a single quality seems to illustrate a
+like error. There is good reason to suppose that this impression arises
+through, a difference of brightness in the two retinal images due to the
+regularly reflected light. And so when this inequality of retinal
+impression is imitated, as it may easily be by combining a black and a
+white surface in a stereoscope, we imagine that we are looking at one
+lustrous surface. (See Helmholtz, _Physiologische Optik_, p. 782, etc.,
+and _Populaere wissenschaftliche Vortraege_, 2tes Heft, p. 80.)
+
+[23] The conditions of the production of these double images have been
+accurately determined by Helmholtz, who shows that the coalescence of
+impressions takes place whenever the object is so situated in the field
+of vision as to make it practically necessary that it should be
+recognized as one.
+
+[24] These illusions are, of course, due in part to inattention, since
+close critical scrutiny is often sufficient to dispel them. They are
+also largely promoted by a preconception that the event is going to
+happen in a particular way. But of this more further on. I may add that
+the late Professor Clifford has argued ingeniously against the idea of
+the world being a continuum, by extending this idea of the wheel of
+life. (See _Lectures and Essays_, i. p. 112, _et seq._)
+
+[25] It is supposed that in the case of every sense-organ there is
+always some minimum forces of stimulus at work, the effect of which on
+our consciousness is _nil_.
+
+[26] See Helmholtz, _Physiologische Optik_, p. 603. Helmholtz's
+explanation is criticised by Dr. Hoppe, in the work already referred to
+(sec. vii), though I cannot see that his own theory of these movements
+is essentially different. The apparent movement of objects in vertigo,
+or giddiness, is probably due to the loss, through a physical cause, of
+the impressions made by the pressure of the fluid contents of the ear on
+the auditory fibres, by which the sense of equilibrium and of rotation
+is usually received. (See Ferrier, _Functions of the Brain_, pp. 60,
+61.)
+
+[27] I do not need here to go into the question whether, as Johannes
+Mueller assumed, this is an original attribute of nerve-structure, or
+whether, as Wundt suggests, it is due simply to the fact that certain
+kinds of nervous fibre have, in the course of evolution, been slowly
+adapted to one kind of stimulus.
+
+[28] I here refer to what is commonly supposed to be the vague innate
+difference of sensation according to the local origin, before this is
+rendered precise, and added to by experience and association.
+
+[29] The illusory character of this simple mode of perception is seen
+best, perhaps, in the curious habit into which we fall of referring a
+sensation of contact or discomfort to the edge of the teeth, the hair,
+and the other insentient structures, and even to anything customarily
+attached to the sentient surface, as dress, a pen, graving tool, etc. On
+these curious illusions, see Lotze, _Mikrokosmus_, third edit., vol. ii.
+p. 202, etc.; Taine, _De l'Intelligence_, tom. ii. p. 83, _et seq._
+
+[30] Quoted by G.H. Lewes, _Problems of Life and Mind_, third series, p.
+335. These illusions are supposed to involve an excitation of the
+nerve-fibres (whether sensory or motor) which run to the muscles and
+yield the so-called muscular sensations.
+
+[31] It is brought out by Griesinger (_loc. cit._) and the other writers
+on the pathology of illusion already quoted, that in the case of
+subjective sensations of touch, taste, and smell, no sharp line can be
+drawn between illusion and hallucination.
+
+[32] For a fuller account of these pathological disturbances of
+sensibility, see Griesinger; also Dr. A. Mayer, _Die Sinnestaeuschungen_.
+
+[33] Helmholtz, _op. cit._, p. 600, _et seq._ These facts seem to point
+to the conclusion that at least some of the feelings by which we know
+that we are expending muscular energy are connected with the initial
+stage of the outgoing nervous process in the motor centres. In other
+pathological conditions the sense of weight by the muscles of the arms
+is similarly confused.
+
+[34] Wundt (_Physiologische Psychologie_, p. 653) would exclude from
+illusions all those errors of sense-perception which have their
+foundation in the normal structure and function of the organs of sense.
+Thus, he would exclude the effects of colour-contrast, _e.g._ the
+apparent modification of two colours in, juxtaposition towards their
+common boundary, which probably arises (according to E. Hering) from
+some mutual influence of the temporary state of activity of adjacent
+retinal elements. To me, however, these appear to be illusions, since
+they may be brought under the head of wrong _interpretations_ of
+sense-impressions. When we see a grey patch as rose-red, as though it
+were so independently of the action of the complementary light
+previously or simultaneously, that is to say, as though it would appear
+rose-red to an eye independently of this action, we surely misinterpret.
+
+[35] Quoted by G.H. Lewes, _loc. cit._, p. 257.
+
+[36] The subject of the perception of movement is too intricate to be
+dealt with fully here. I have only touched on it so far as necessary to
+illustrate our general principle. For a fuller treatment of the subject,
+see the work of Dr. Hoppe, already referred to.
+
+[37] The perception of magnitude is closely connected with that of
+distance, and is similarly apt to take an illusory form. I need only
+refer to the well-known simple optical contrivances for increasing the
+apparent magnitude of objects. I ought, perhaps, to add that I do not
+profess to give a complete account of optical illusions here, but only
+to select a few prominent varieties, with a view to illustrate general
+principles of illusion. For a fuller account of the various mechanical
+arrangements for producing optical illusion, I must refer the reader to
+the writings of Sir D. Brewster and Helmholtz.
+
+[38] Painters are well aware that the colours at the red end of the
+spectrum are apt to appear as advancing, while those of the violet end
+are known as retiring. The appearance of relief given by a gilded
+pattern on a dark blue as ground, is in part referable to the principle
+just referred to. In addition, it appears to involve a difference in the
+action of the muscles of accommodation in the successive adaptations of
+the eye to the most refrangible and the least refrangible rays. (See
+Bruecke, _Die Physiologie der Farben_, sec. 17.)
+
+[39] Helmholtz tells us (_Populaere wissenschaftliche Vortraege_, 3tes
+Heft, p. 64) that even in a stereoscopic arrangement the presence of a
+wrong cast shadow sufficed to disturb the illusion.
+
+[40] Among the means of giving a vivid sense of depth to a picture,
+emphasized by Helmholtz, is diminishing magnitude. It is obvious that
+the perceptions of real magnitude and distance are mutually involved.
+When, for example, a picture represents a receding series of objects, as
+animals, trees, or buildings, the sense of the third dimension, is
+rendered much more clear.
+
+[41] A striking example of this was given in a painting, by Andsell, of
+a sportsman in the act of shooting, exhibited in the Royal Academy in
+1879.
+
+[42] This is at least true of all near objects.
+
+[43] Helmholtz remarks _(op. cit._, p. 628) that the difficulty of
+seeing the convex cast as concave is probably due to the presence of the
+cast shadow. This has, no doubt, some effect: yet the consideration
+urged in the text appears to me to be the most important one.
+
+[44] _Populaere wissenschaftliche Vortraege_, 3tes Heft, pp. 71, 72.
+
+[45] See, on this point, some excellent remarks by G.H. Lewes, _Problems
+of Life and Mind_, third series, vol. ii. p. 275.
+
+[46] To some extent this applies to the changes of apparent magnitude
+due to altered position. Thus, we do not attend to the reduction of the
+height of a small object which we are wont to handle, when it is placed
+far below the level of the eye. And hence the error people make in
+judging of the point in the wall or skirting which a hat will reach when
+placed on the ground.
+
+[47] I refer to the experiments made by Exner, Wundt, and others, in
+determining the time elapsing between the giving of a signal to a person
+and the execution of a movement in response. "It is found," says Wundt,
+"by these experiments that the exact moment at which a sense-impression
+is perceived depends on the amount of preparatory self-accommodation of
+attention." (See Wundt, _Physiologische Psychologie_, ch. xix.,
+especially p. 735. _et seq._)
+
+[48] Quoted by Helmholtz, _op. cit._, p. 626.
+
+[49] When the drawing, by its adherence to the laws of perspective, does
+not powerfully determine the eye to see it in one way rather than in the
+other (as in Figs. 5 to 7), the disposition to see the one form rather
+than the other points to differences in the frequency of the original
+forms in our daily experience. At the same time, it is to be observed
+that, after looking at the drawing for a time under each aspect, the
+suggestion now of the one and now of the other forces itself on the mind
+in a curious and unaccountable way.
+
+[50] _Ueber die phantastischen Gesichsterscheinungen_, p. 45.
+
+[51] Another side of histrionic illusion, the reading of the imitated
+feelings into the actors' minds, will be dealt with in a later chapter.
+
+[52] In a finished painting of any size this preparation is hardly
+necessary. In these cases, in spite of the great deviations from truth
+in pictorial representation already touched on, the amount of essential
+agreement is so large and so powerful in its effect that even an
+intelligent animal will experience an illusion. Mr. Romanes sends me an
+interesting account of a dog, that had never been accustomed to
+pictures, having been put into a state of great excitement by the
+introduction of a portrait into a room, on a level with his eye. It is
+not at all improbable that the lower animals, even when sane, are
+frequently the subjects of slight illusion. That animals dream is a fact
+which is observed as long ago as the age of Lucretius.
+
+[53] This kind of illusion is probably facilitated by the fact that the
+eye is often performing slight movements without any clear consciousness
+of them. See what was said about the limits of sensibility, p. 50.
+
+[54] _Mental Physiology_, fourth edit., p. 158.
+
+[55] In persons of very lively imagination the mere representation of an
+object or event may suffice to bring about such a semblance of
+sensation. Thus, M. Taine (_op. cit._, vol. i. p. 94) vouches for the
+assertion that "one of the most exact and lucid of modern novelists,"
+when working out in his imagination the poisoning of one of his
+fictitious characters, had so vivid a gustatory sensation of arsenic
+that he was attacked by a violent fit of indigestion.
+
+[56] Mentioned by Dr. Carpenter (_Mental Physiology_, p. 207), where
+other curious examples are to be found.
+
+[57] See _Annales Medico-Psychologiques_, tom. vi. p. 168, etc.; tom.
+vii. p. 1. etc.
+
+[58] I have already touched on the resonance of a sense-impression when
+the stimulus has ceased to act (see p. 55). The remarks in the text hold
+good of all such after-impressions, in so far as they take the form of
+fully developed percepts. A good example is the recurrence of the images
+of microscopic preparations, to which the anatomist is liable. (See
+Lewes, _Problems of Life and Mind_, third series, vol. ii. p. 299.)
+Since a complete hallucination is supposed to involve the peripheral
+regions of the nerve, the mere fact of shutting the eye would not, it is
+clear, serve as a test of the origin of the illusion.
+
+[59] That subjective sensation may become the starting-point in complete
+hallucination is shown in a curious instance given by Lazarus, and
+quoted by Taine, _op. cit._, vol. i. p. 122, _et seq._ The German
+psychologist relates that, on one occasion in Switzerland, after gazing
+for some time on a chain of snow-peaks, he saw an apparition of an
+absent friend, looking like a corpse. He goes on to explain that this
+phantom was the product of an image of recollection which somehow
+managed to combine itself with the (positive) after-image left by the
+impression of the snow-surface.
+
+[60] For an account of Mr. Galton's researches, see _Mind_, No. xix.
+Compare, however, Professor Bain's judicious observations on these
+results in the next number of _Mind_. The liability of children to take
+images for percepts, is illustrated by the experiences related in a
+curious little work, _Visions_, by E.H. Clarke, M.D. (Boston, U.S.,
+1878), pp. 17, 46, and 212.
+
+[61] A common way of describing the relation of the hallucinatory to
+real objects, is to say that the former appear partly to cover and hide
+the latter.
+
+[62] Griesinger remarks that the forms of the hallucinations of the
+insane rarely depend on sense-disturbances alone. Though these are often
+the starting-point, it is the whole mental complexion of the time which
+gives the direction to the imagination. The common experience of seeing
+rats and mice running about during a fit of _delirium tremens_ very well
+illustrates the co-operation of peripheral impressions not usually
+attended to, and possibly magnified by the morbid state of sensibility
+of the time (in this case flying spots, _muscae volitantes_), with
+emotional conditions. (See Griesinger, _loc. cit._, p. 96.)
+
+[63] Wundt (_Physiologische Psychologie_, p. 652) tells us of an insane
+woodman who saw logs of wood on all hands in front of the real objects.
+
+[64] It is stated by Baillarger (Memoires de l'Academie Royale de
+Medicine, tom. xii. p. 273, etc.) that while visual hallucinations are
+more frequent than auditory in healthy life, the reverse relation holds
+in disease. At the same time, Griesinger remarks (_loc. cit._, p. 98)
+that visual hallucinations are rather more common than auditory in
+disease also. This is what we should expect from the number of
+subjective sensations connected with the peripheral organ of vision. The
+greater relative frequency of auditory hallucinations in disease, if
+made out, would seem to depend on the close connection between
+articulate sounds and the higher centres of intelligence, which centres
+are naturally the first to be thrown out of working order. It is
+possible, moreover, that auditory hallucinations are quite as common as
+visual in states of comparative health, though more easily overlooked.
+Professor Huxley relates that he is liable to auditory though not to
+visual hallucinations. (See _Elementary Lessons in Physiology_, p. 267.)
+
+[65] See Baillarger, _Memoires de l'Academie Royale de Medicine_, tom.
+xii. p. 273, _et seq._
+
+[66] See Baillarger, _Annales Medico-Psychologiques_, tom. vi. p. 168
+_et seq._; also tom. xii. p. 273, _et seq._ Compare Griesinger, _op.
+cit._ In a curious work entitled _Du Demon de Socrate_ (Paris, 1856), M.
+Lelut seeks to prove that the philosopher's admonitory voice was an
+incipient auditory hallucination symptomic of a nascent stage of mental
+alienation.
+
+[67] This is well brought out by Dr. J. Hughlings Jackson, in the papers
+in _Brain_, already referred to.
+
+[68] _Friend_, vol. i. p. 248. The story is referred to by Sir W. Scott
+in his _Demonology and Witchcraft_.
+
+[69] See E.B. Tylor, _Primitive Culture_, ch. xi.; _cf._ Herbert
+Spencer, _Principles of Sociology_, ch. x.
+
+[70] For a fuller account of the different modes of
+dream-interpretation, see my article "Dream," in the ninth edition of
+the _Encyclopaedia Britannica_.
+
+[71] For a fuller account of the reaction of dreams on waking
+consciousness, see Paul Radestock, _Schlaf und Traum_. The subject is
+touched on later, under the Illusions of Memory.
+
+[72] For an account of the latest physiological hypotheses as to the
+proximate cause of sleep, see Radestock, _op. cit._, appendix.
+
+[73] Plutarch, Locke, and others give instances of people who never
+dreamt. Lessing asserted of himself that he never knew what it was to
+dream.
+
+[74] The error touched on here will be fully dealt with under Illusions
+of Memory.
+
+[75] For a very full, fair, and thoughtful discussion of this whole
+question, see Radestock, _op. cit._, ch. iv.
+
+[76] This may be technically expressed by saying that the liminal
+intensity (Schwelle) is raised during sleep.
+
+[77] See Wundt, _Physiologische Psychologie_, pp. 188-191.
+
+[78] There is, indeed, sometimes an undertone of critical reflection,
+which is sufficient to produce a feeling of uncertainty and
+bewilderment, and in very rare cases to amount to a vague consciousness
+that the mental experience is a dream.
+
+[79] _Observations on Man_, Part I. ch. iii, sec. 5.
+
+[80] Quoted by Radestock, _op. cit._, p. 110.
+
+[81] _Le Sommeil et les Reves_, p. 132, _et seq._
+
+[82] _Das Leben des Traumes_, p. 369. Other instances are related by
+Beattie and Abercrombie.
+
+[83] _Le Sommeil et les Reves_, p. 42, _et seq._
+
+[84] _Beitraege sur Physiognosie und Heautognosie_, p. 256. For other
+cases see H. Meyer, _Physiologie der Nervenfaser_, p. 309; and
+Struempell, _Die Natur und Entstehung der Traeume_, p. 125.
+
+[85] A very clear and full account of these organic sensations, or
+common sensations, has recently appeared from the pen of A. Horwicz in
+the _Vierteljahrsschrift fuer wissenschaftliche Philosophie_, iv.
+Jahrgang 3tes Heft.
+
+[86] Schopenhauer uses this hypothesis in order to account for the
+apparent reality of dream-illusions. He thinks these internal sensations
+may be transformed by the "intuitive function" of the brain (by means of
+the "forms" of space, time, etc.) into quasi-realities, just as well as
+the subjective sensations of light, sound, etc., which arise in the
+organs of sense in the absence of external stimuli. (See _Versuch ueber
+das Geisterschen: Werke_, vol. v. p. 244, _et seq._)
+
+[87] _Das Alpdruecken_, pp. 8, 9, 27.
+
+[88] It is this fact which justifies writers in assigning a prognostic
+character to dreams.
+
+[89] A part of the apparent exaggeration in our dream-experiences may be
+retrospective, and due to the effect of the impression of wonder which
+they leave behind them. (See Struempell, _Die Natur und Entstehung der
+Traeume_.)
+
+[90] _Cf._ Radestock, _op. cit._, pp. 131, 132.
+
+[91] I was on one occasion able to observe this process going on in the
+transition from waking to sleeping. I partly fell asleep when suffering
+from toothache. Instantly the successive throbs of pain transformed
+themselves into a sequence of visible movements, which I can only
+vaguely describe as the forward strides of some menacing adversary.
+
+[92] Even the "unconscious impressions" of waking hours, that is to say,
+those impressions which are so fugitive as to leave no psychical trace
+behind, may thus rise into the clear light of consciousness during
+sleep. Maury relates a curious dream of his own, in which there appeared
+a figure that seemed quite strange to him, though he afterwards found
+that he must have been in the habit of meeting the original in a street
+through which he was accustomed to walk (_loc. cit._, p. 124).
+
+[93] See p. 53.
+
+[94] See Maury, _loc. cit._, p. 146.
+
+[95] See what was said respecting the influence of a dominant emotional
+agitation on the interpretation of actual sense-impressions.
+
+[96] It is proved experimentally that the ear has a much closer organic
+connection with the vocal organ than the eye has. Donders found that the
+period required for responding vocally to a sound-signal is less than
+that required for responding in the same way to a light-signal.
+
+[97] On the nature of this impulse, as illustrated in waking and in
+sleep, see the article by Delboeuf, "Le Sommeil et les Reves," in
+the _Revue Philosophique_, June, 1880, p. 636.
+
+[98] _Physiologische Psychologie_, p. 660.
+
+[99] I may, perhaps, observe, after giving two dreams which have to do
+with mathematical operations, that, though I was very fond of them in my
+college days, I have long ceased to occupy myself with these processes.
+I would add, by way of redeeming my dream-intelligence from a deserved
+charge of silliness, that I once performed a respectable intellectual
+feat when asleep. I put together the riddle, "What might a wooden ship
+say when her side was stove in? Tremendous!" (Tree-mend-us). I was aware
+of having tried to improve on the form of this pun. I am happy to say I
+am not given to punning during waking life, though I had a fit of it
+once. It strikes me that punning, consisting as it does essentially of
+overlooking sense and attending to sound, is just such a debased kind of
+intellectual activity as one might look for in sleep.
+
+[100] See Radestock, _op. cit._, ch. ix.; _Vergleichung des Traumes mit
+dem Wahnsinn_.
+
+[101] For Spinoza's experience, given in his own words, see Mr. F.
+Pollock's _Spinoza_, p. 57; _cf._ what Wundt says on his experience,
+_Physiologische Psychologie_, p. 648, footnote 2.
+
+[102] See an interesting account of "Recent Researches on Hypnotism," by
+G. Stanley Hall, in _Mind_, January, 1881.
+
+[103] I need hardly observe that physiology shows that there is no
+separation of different elementary colour-sensations which are locally
+identical.
+
+[104] This kind of error is, of course, common to all kinds of
+cognition, in so far as they involve comparison. Thus, the presence of
+the excitement of the emotion of wonder at the sight of an unusually
+large object, say a mountain, disposes the mind to look on it as the
+largest of its class. Such illusions come midway between presentative
+and representative illusions. They might, perhaps, be specially marked
+off as illusions of "judgment."
+
+[105] So far as any mental state, though originating in a fusion of
+elements, is now unanalyzable by the best effort of attention, we must
+of course regard it in its present form as simple. This distinction
+between what is simple or complex in its present nature, and what is
+originally so, is sometimes overlooked by psychologists. Whether the
+feelings and ideas here referred to are now simple or complex, cannot, I
+think, yet be very certainly determined. To take the idea of space, I
+find that after practice I recognize the ingredient of muscular feeling
+much better than I did at first. And this exactly answers to Helmholtz's
+contention that elementary sensations as partial tones can be detected
+after practice. Such separate recognition may be said to depend on
+correct representation. On the other hand, it must be allowed that there
+is room for the intuitionist to say that the associationist is here
+reading something into the idea which does not belong to it. It is to be
+added that the illusion which the associationist commonly seeks to
+fasten on his opponent is that of confusing final with original
+simplicity. Thus, he says that, though the idea of space may now to all
+intents and purposes be simple, it was really built up out of many
+distinct elements. More will be said on the relation of questions of
+nature and genesis further on.
+
+[106] I may as well be frank and say that I myself, assuming free-will
+to be an illusion, have tried to trace the various threads of influence
+which have contributed to its remarkable vitality. (See _Sensation and
+Intuition_, ch. v., "The Genesis of the Free-Will Doctrine.")
+
+[107] I purposely leave aside here the philosophical question, whether
+the knowledge of others' feelings is intuitive in the sense of being
+altogether independent of experience, and the manifestation of a
+fundamental belief. The inherited power referred to in the text might,
+of course, be viewed as a transmitted result of ancestral experience.
+
+[108] I here assume, along with G.H. Lewes and other competent dramatic
+critics, that the actor does not and dares not feel what he expresses,
+at least not in the perfectly spontaneous way, and in the same measure
+in which he appears to feel it.
+
+[109] The illusory nature of much of this emotional interpretation of
+music has been ably exposed by Mr. Gurney. (See _The Power of Sound_, p.
+345, _et seq._)
+
+[110] The reader will note that this impulse is complementary to the
+other impulse to view all mental states as analogous to impressions
+produced by external things, on which I touched in the last chapter.
+
+[111] Errors of memory have sometimes been called "fallacies," as, for
+example, by Dr. Carpenter (_Human Physiology_, ch. x.). While preferring
+the term "illusion," I would not forget to acknowledge my indebtedness
+to Dr. Carpenter, who first set me seriously to consider the subject of
+mnemonic error.
+
+[112] From this it would appear to follow that, so far as a percept is
+representative, recollection must be re-representative.
+
+[113] The relation of memory to recognition is very well discussed by M.
+Delboeuf, in connection with a definition of memory given by
+Descartes. (See the article "Le Sommeil et les Reves," in the _Revue
+Philosophique_, April, 1880, p. 428, _et seq._)
+
+[114] A very interesting account of the most recent physiological theory
+of memory is to be found in a series of articles, bearing the title, "La
+Memoire comme fait biologique," published in the _Revue Philosophique_,
+from the pen of the editor, M. Th. Ribot. (See especially the _Revue_ of
+May, 1880, pp. 516, _et seq._) M. Ribot speaks of the modification of
+particular nerve-elements as "the static base" of memory, and of the
+formation of nerve-connections by means of which the modified element
+may be re-excited to activity as "the dynamic base of memory" (p. 535).
+
+[115] What constitutes the difference between such a progressive and a
+retrogressive movement is a point that will be considered by-and-by.
+
+[116] It is not easy to say how far exceptional conditions may serve to
+reinstate the seemingly forgotten past. Yet the experiences of dreamers
+and of those who have been recalled to consciousness after partial
+drowning, whatever they may prove with respect to the revivability of
+remote experiences, do not lead us to imagine that the range of our
+definitely localizing memory is a wide one.
+
+[117] _Der Zeitsinn nach Versuchen_, p. 36, _et seq._
+
+[118] _Physiologische Psychologie_, p. 782.
+
+[119] Wundt refers these errors to variations in the state of
+preadjustment of the attention to impressions and representations,
+according as they succeed one another slowly or rapidly. There is little
+doubt that the effects of the state of tension of the apparatus of
+attention, are involved here, though I am disposed to think that Wundt
+makes too much of this circumstance. (See _Physiologische Psychologie_,
+pp. 782, 783. I have given a fuller account of Wundt's theory in _Mind_,
+No. i.)
+
+[120] Strictly speaking, it would occupy more time, since the effort of
+recalling each successive link in the chain would involve a greater
+interval between any two images than that between the corresponding
+experiences.
+
+[121] I need hardly say that there is no sharp distinction between these
+two modes of subjective appreciation. Our estimate of an interval as it
+passes is really made up of a number of renewed anticipations and
+recollections of the successive experiences. Yet we can say broadly that
+this is a prospective estimate, while that which is formed when the
+period has quite expired must be altogether retrospective.
+
+[122] See an interesting paper on "Consciousness of Time," by Mr. G. J.
+Romanes, in _Mind_ (July, 1878).
+
+[123] It is well known that there is, from the first, a gradual falling
+off in the strength of a sensation of light when a moderately bright
+object is looked at.
+
+[124] _Cf._ Hartley, _Observations on Man_, Part I. ch. iii. sec. 4
+(fifth edit., p. 391).
+
+[125] See Dr. Carpenter's _Mental Physiology_, fourth edit, p. 456.
+
+[126] This is, perhaps, what is meant by saying that people recall their
+past enjoyments more readily than their sufferings. Yet much seems to
+turn on temperament and emotional peculiarities. (For a fuller
+discussion of the point, see my _Pessimism_, p. 344.)
+
+[127] The only exception to this that I can think of is to be found in
+the power which I, at least, possess, after looking at a new object, of
+representing it as a familiar one. Yet this may be explained by saying
+that in the case of every object which is clearly apprehended there must
+be vague revivals of _similar_ objects perceived before. Oases in which
+recent experiences tend, owing to their peculiar nature, very rapidly to
+assume the appearance of old events, will be considered presently.
+
+[128] _Mental Physiology_, p. 456.
+
+[129] _Mental Physiology_, second edit., p. 172.
+
+[130] _Loc. cit._, p. 390.
+
+[131] This source of error has not escaped the notice of autobiographers
+themselves. See the remarks of Goethe in the opening passages of his
+_Wahrheit und Dichtung_.
+
+[132] One wonders whether those persons who, in consequence of an injury
+to their brain, periodically pass from a normal into an abnormal
+condition of mind, in each of which there is little or no memory of the
+contents of the other state, complete their idea of personal continuity
+in each state by the same kind of process as that described in the text.
+
+[133] The reader will remark that this condition of clear intellectual
+consciousness, namely, a certain degree of similarity and continuity of
+character in our successive mental states, is complementary to the other
+condition, constant change, already referred to. It may, perhaps, be
+said that all clear consciousness lies between two extremes of excessive
+sameness and excessive difference.
+
+[134] It follows that any great transformation of our environment may
+lead to a partial confusion with respect to self. For not only do great
+and violent changes in our surroundings beget profound changes in our
+feelings and ideas, but since the idea of self is under one of its
+aspects essentially that of a relation to not-self, any great revolution
+in the one term, will confuse the recognition of the other. This fact is
+expressed in the common expression that we "lose ourselves" when in
+unfamiliar surroundings, and the process of orientation, or "taking our
+bearings," fails.
+
+[135] On these disturbances of memory and self-recognition in insanity,
+see Griesinger, _op. cit._, pp. 49-51; also Ribot, "Des Desordres
+Generaux de la Memoire," in the _Revue Philosophique_, August, 1880. It
+is related by Leuret (_Fragments Psych. sur la Folie_, p. 277) that a
+patient spoke of his former self as "la personne de moi-meme."
+
+[136] In the following account of the process of belief and its errors,
+I am going over some of the ground traversed by my essay on _Belief, its
+Varieties and Conditions_ ("Sensation and Intuition," ch. iv.). To this
+essay I must refer the reader for a fuller analysis of the subject.
+
+[137] For an account of the difference of mechanism in memory and
+expectation, see Taine, _De l'Intelligence_, 2ieme partie, livre
+premier, ch. ii. sec. 6.
+
+[138] J.S. Mill distinguishes expectation as a radically distinct mode
+of belief from memory, but does not bring out the contrast with respect
+to activity here emphasized (James Mill's _Analysis of the Human Mind_,
+edited by J.S. Mill, p. 411, etc.). For a fuller statement of my view of
+the relation of belief to action, as compared with that of Professor
+Bain, see my earlier work.
+
+[139] For some good remarks on the logical aspects of future events as
+matters of fact, see Mr. Venn's _Logic of Chance_, ch. x.
+
+[140] James Mill's _Analysis of the Human Mind_, edited by J.S. Mill,
+vol. i p. 414, _et seq._
+
+[141] _Principles of Geology_, ch. iii.
+
+[142] To make this rough analysis more complete, I ought, perhaps, to
+include the effect of all the errors of introspection, memory, and
+spontaneous belief, into which the person himself falls, in so far as
+they communicate themselves to others.
+
+[143] In the case of a vain woman thinking herself much more pretty than
+others think her, the error is still more obviously one connected with a
+belief in objective fact.
+
+[144] _The Study of Sociology_, ch. ix.
+
+[145] As a matter of fact, the proportion of accurate knowledge to error
+is far larger in the case of classes than of individuals. Propositions
+with general terms for subject are less liable to be faulty than
+propositions with singular terms for subject.
+
+[146] For a description of each of these extremes of boundless gaiety
+and utter despondency, see Griesinger, _op. cit._, Bk. III. ch. i. and
+ii. The relation of pessimism to pathological conditions is familiar
+enough; less familiar is the relation of unrestrained optimism. Yet
+Griesinger writes that among the insane "boundless hilarity," with "a
+feeling of good fortune," and a general contentment with everything, is
+as frequent as depression and repining (see especially p. 281, also pp.
+64, 65).
+
+[147] It has been seen that, from a purely psychological point of view,
+even what looks at first like pure presentative cognition, as, for
+example, the recognition of a present feeling of the mind, involves an
+ingredient of representation.
+
+[148] See especially what was said about the _rationale_ of illusions of
+perception, pp. 37, 38.
+
+[149] I say "usually," because, as we have seen, there may sometimes be
+a permanent and even an inherited predisposition to active illusion in
+the individual temperament and nervous organization.
+
+[150] See what was said on the nature of passive illusions of sense (pp.
+44, 68, 70, etc.) The logical character of illusion might be brought out
+by saying that it resembles the fallacy which is due to reasoning from
+an approximate generalization as though it were a universal truth. In
+thus identifying illusion and fallacy, I must not be understood to say
+that there is, strictly speaking, any such thing as an unconscious
+reasoning process. On the contrary, I hold that it is a contradiction to
+talk of any _mental_ operation as altogether unconscious. I simply wish
+to show that, by a kind of fiction, illusion may be described as the
+result of a series of steps which, if separately unfolded to
+consciousness (as they no longer are), would correspond to those of a
+process of inference. The fact that illusion arises by a process of
+contraction out of conscious inference seems to justify this use of
+language, even apart from the fact that the nervous processes in the two
+cases are pretty certainly the same.
+
+[151] If we turn from the region of physical to that of moral ideas, we
+see this historical collision between common and individual conviction
+in a yet more impressive form. The teacher of a new moral truth has
+again and again been set down to be an illusionist by a society which
+was itself under the sway of a long-reigning error. As George Eliot
+observes, "What we call illusions are often, in truth, a wider vision of
+past and present realities--a willing movement of a man's soul with the
+larger sweep of the world's forces."
+
+[152] To make this account of the philosophic problem of the
+object-world complete, I ought to touch not only on the distinction
+between the vulgar and the scientific view of material things, but also
+on the distinction, within physical science, between the less and the
+more abstract view roughly represented by molar and molecular physics.
+
+[153] For an excellent account of the distinction between the scientific
+and the philosophic point of view, see Mr. Shadworth Hodgson's
+_Philosophy of Reflection_, Bk. I. chs. i. and iii.; also Bk. III. chs.
+vii. and viii.
+
+[154] I hold, in spite of Berkeley's endeavours to reconcile his
+position with that of common sense, that the popular view does at least
+tend in this direction. That is to say, the every-day habit, when
+considering the external world, of abstracting from particular minds,
+leads on insensibly to that complete detachment of it from mind in
+general which expresses itself in the first stage of philosophic
+reflection, crude realism. The physicist appears to me, both from the
+first essays in Greek "nature-philosophy," as also from the not
+infrequent confusion even to-day between a perfectly safe "scientific
+materialism" and a highly questionable philosophic materialism, to share
+in this tendency to take separate consideration for separate existence.
+Each new stage of abstraction in physical science gives birth to a new
+attempt to find an independent reality, a thing-in-itself, hidden
+further away from sense.
+
+[155] See the interesting autobiographical record of the growth of
+philosophic doubt in the _Premiere Meditation_ of Descartes.
+
+[156] The appeal is not, as we have seen, invariably from sight to
+touch, but may be in the reverse direction, as in the recognition of the
+duality of the points of a pair of compasses, which seem one to the
+tactual sense.
+
+[157] I might further remark that this "collective experience" includes
+previously detected illusions of ourselves and of others.
+
+[158] M. Taine frankly teaches that what is commonly called accurate
+perception is a "true hallucination" (_De l'Intelligence_, 2ieme partie,
+Livre I. ch. i. sec. 3).
+
+[159] It only seems to do so, apart from philosophic assumptions, in
+certain cases where experience testifies to a uniform untrustworthiness
+of the origin. For example, we may, on grounds of matter of fact and
+experience, be disposed to distrust any belief that we recognize as
+springing from an emotional source, from the mind's feelings and wishes.
+
+I may add that a so-called intuitive belief may refer to a matter of
+fact which can be tested by the facts of experience and by scientific
+methods. Thus, for example, the old and now exploded form of the
+doctrine of innate ideas, which declared that children were born with
+certain ideas ready made, might be tested by observation of childhood,
+and reasoning from its general intellectual condition. The same applies
+to the physiological theories of space-perception, supposed to be based
+on Kant's doctrine, put forward in Germany by Johannes Mueller and the
+"nativistic school." (See my exposition and criticism of these doctrines
+in _Mind_, April, 1878, pp. 168-178 and 193-195.)
+
+
+
+
+
+
+End of the Project Gutenberg EBook of Illusions, by James Sully
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