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diff --git a/old/1hsci10.txt b/old/1hsci10.txt new file mode 100644 index 0000000..a32048b --- /dev/null +++ b/old/1hsci10.txt @@ -0,0 +1,9180 @@ +Project Gutenberg Etext of A History of Science, V 1, by Williams +#1 in our series by Henry Smith Williams + + +Copyright laws are changing all over the world, be sure to check +the copyright laws for your country before posting these files!! + +Please take a look at the important information in this header. +We encourage you to keep this file on your own disk, keeping an +electronic path open for the next readers. Do not remove this. + + +**Welcome To The World of Free Plain Vanilla Electronic Texts** + +**Etexts Readable By Both Humans and By Computers, Since 1971** + +*These Etexts Prepared By Hundreds of Volunteers and Donations* + +Information on contacting Project Gutenberg to get Etexts, and +further information is included below. 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WILLIAMS, M.D. + +IN FIVE VOLUMES +VOLUME I. + +THE BEGINNINGS OF SCIENCE + + + + +BOOK I. + +CONTENTS + +CHAPTER I. PREHISTORIC SCIENCE + +CHAPTER II. EGYPTIAN SCIENCE + +CHAPTER III. SCIENCE OF BABYLONIA AND ASSYRIA + +CHAPTER IV. THE DEVELOPMENT OF THE ALPHABET + +CHAPTER V. THE BEGINNINGS OF GREEK SCIENCE + +CHAPTER VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + +CHAPTER VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + +CHAPTER VIII. POST-SOCRATIC SCIENCE AT ATHENS + +CHAPTER IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC +PERIOD + +CHAPTER X. SCIENCE OF THE ROMAN PERIOD + +CHAPTER XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + +APPENDIX + + +A HISTORY OF SCIENCE + +BOOK I + +Should the story that is about to be unfolded be found to lack +interest, the writers must stand convicted of unpardonable lack +of art. Nothing but dulness in the telling could mar the story, +for in itself it is the record of the growth of those ideas that +have made our race and its civilization what they are; of ideas +instinct with human interest, vital with meaning for our race; +fundamental in their influence on human development; part and +parcel of the mechanism of human thought on the one hand, and of +practical civilization on the other. Such a phrase as +"fundamental principles" may seem at first thought a hard saying, +but the idea it implies is less repellent than the phrase itself, +for the fundamental principles in question are so closely linked +with the present interests of every one of us that they lie +within the grasp of every average man and woman--nay, of every +well-developed boy and girl. These principles are not merely the +stepping-stones to culture, the prerequisites of knowledge--they +are, in themselves, an essential part of the knowledge of every +cultivated person. + +It is our task, not merely to show what these principles are, but +to point out how they have been discovered by our predecessors. +We shall trace the growth of these ideas from their first vague +beginnings. We shall see how vagueness of thought gave way to +precision; how a general truth, once grasped and formulated, was +found to be a stepping-stone to other truths. We shall see that +there are no isolated facts, no isolated principles, in nature; +that each part of our story is linked by indissoluble bands with +that which goes before, and with that which comes after. For the +most part the discovery of this principle or that in a given +sequence is no accident. Galileo and Keppler must precede Newton. +Cuvier and Lyall must come before Darwin;--Which, after all, is +no more than saying that in our Temple of Science, as in any +other piece of architecture, the foundation must precede the +superstructure. + +We shall best understand our story of the growth of science if we +think of each new principle as a stepping-stone which must fit +into its own particular niche; and if we reflect that the entire +structure of modern civilization would be different from what it +is, and less perfect than it is, had not that particular +stepping-stone been found and shaped and placed in position. +Taken as a whole, our stepping-stones lead us up and up towards +the alluring heights of an acropolis of knowledge, on which +stands the Temple of Modern Science. The story of the building of +this wonderful structure is in itself fascinating and beautiful. + + + +I. PREHISTORIC SCIENCE + +To speak of a prehistoric science may seem like a contradiction +of terms. The word prehistoric seems to imply barbarism, while +science, clearly enough, seems the outgrowth of civilization; but +rightly considered, there is no contradiction. For, on the one +hand, man had ceased to be a barbarian long before the beginning +of what we call the historical period; and, on the other hand, +science, of a kind, is no less a precursor and a cause of +civilization than it is a consequent. To get this clearly in +mind, we must ask ourselves: What, then, is science? The word +runs glibly enough upon the tongue of our every-day speech, but +it is not often, perhaps, that they who use it habitually ask +themselves just what it means. Yet the answer is not difficult. A +little attention will show that science, as the word is commonly +used, implies these things: first, the gathering of knowledge +through observation; second, the classification of such +knowledge, and through this classification, the elaboration of +general ideas or principles. In the familiar definition of +Herbert Spencer, science is organized knowledge. + +Now it is patent enough, at first glance, that the veriest savage +must have been an observer of the phenomena of nature. But it may +not be so obvious that he must also have been a classifier of his +observations--an organizer of knowledge. Yet the more we consider +the case, the more clear it will become that the two methods are +too closely linked together to be dissevered. To observe outside +phenomena is not more inherent in the nature of the mind than to +draw inferences from these phenomena. A deer passing through the +forest scents the ground and detects a certain odor. A sequence +of ideas is generated in the mind of the deer. Nothing in the +deer's experience can produce that odor but a wolf; therefore the +scientific inference is drawn that wolves have passed that way. +But it is a part of the deer's scientific knowledge, based on +previous experience, individual and racial; that wolves are +dangerous beasts, and so, combining direct observation in the +present with the application of a general principle based on past +experience, the deer reaches the very logical conclusion that it +may wisely turn about and run in another direction. All this +implies, essentially, a comprehension and use of scientific +principles; and, strange as it seems to speak of a deer as +possessing scientific knowledge, yet there is really no absurdity +in the statement. The deer does possess scientific knowledge; +knowledge differing in degree only, not in kind, from the +knowledge of a Newton. Nor is the animal, within the range of its +intelligence, less logical, less scientific in the application of +that knowledge, than is the man. The animal that could not make +accurate scientific observations of its surroundings, and deduce +accurate scientific conclusions from them, would soon pay the +penalty of its lack of logic. + +What is true of man's precursors in the animal scale is, of +course, true in a wider and fuller sense of man himself at the +very lowest stage of his development. Ages before the time which +the limitations of our knowledge force us to speak of as the dawn +of history, man had reached a high stage of development. As a +social being, he had developed all the elements of a primitive +civilization. If, for convenience of classification, we speak of +his state as savage, or barbaric, we use terms which, after all, +are relative, and which do not shut off our primitive ancestors +from a tolerably close association with our own ideals. We know +that, even in the Stone Age, man had learned how to domesticate +animals and make them useful to him, and that he had also learned +to cultivate the soil. Later on, doubtless by slow and painful +stages, he attained those wonderful elements of knowledge that +enabled him to smelt metals and to produce implements of bronze, +and then of iron. Even in the Stone Age he was a mechanic of +marvellous skill, as any one of to-day may satisfy himself by +attempting to duplicate such an implement as a chipped +arrow-head. And a barbarian who could fashion an axe or a knife +of bronze had certainly gone far in his knowledge of scientific +principles and their practical application. The practical +application was, doubtless, the only thought that our primitive +ancestor had in mind; quite probably the question as to +principles that might be involved troubled him not at all. Yet, +in spite of himself, he knew certain rudimentary principles of +science, even though he did not formulate them. + +Let us inquire what some of these principles are. Such an inquiry +will, as it were, clear the ground for our structure of science. +It will show the plane of knowledge on which historical +investigation begins. Incidentally, perhaps, it will reveal to us +unsuspected affinities between ourselves and our remote ancestor. +Without attempting anything like a full analysis, we may note in +passing, not merely what primitive man knew, but what he did not +know; that at least a vague notion may be gained of the field for +scientific research that lay open for historic man to cultivate. + + +It must be understood that the knowledge of primitive man, as we +are about to outline it, is inferential. We cannot trace the +development of these principles, much less can we say who +discovered them. Some of them, as already suggested, are man's +heritage from non-human ancestors. Others can only have been +grasped by him after he had reached a relatively high stage of +human development. But all the principles here listed must surely +have been parts of our primitive ancestor's knowledge before +those earliest days of Egyptian and Babylonian civilization, the +records of which constitute our first introduction to the +so-called historical period. Taken somewhat in the order of their +probable discovery, the scientific ideas of primitive man may be +roughly listed as follows: + +1. Primitive man must have conceived that the earth is flat and +of limitless extent. By this it is not meant to imply that he had +a distinct conception of infinity, but, for that matter, it +cannot be said that any one to-day has a conception of infinity +that could be called definite. But, reasoning from experience and +the reports of travellers, there was nothing to suggest to early +man the limit of the earth. He did, indeed, find in his +wanderings, that changed climatic conditions barred him from +farther progress; but beyond the farthest reaches of his +migrations, the seemingly flat land-surfaces and water-surfaces +stretched away unbroken and, to all appearances, without end. It +would require a reach of the philosophical imagination to +conceive a limit to the earth, and while such imaginings may have +been current in the prehistoric period, we can have no proof of +them, and we may well postpone consideration of man's early +dreamings as to the shape of the earth until we enter the +historical epoch where we stand on firm ground. + +2. Primitive man must, from a very early period, have observed +that the sun gives heat and light, and that the moon and stars +seem to give light only and no heat. It required but a slight +extension of this observation to note that the changing phases of +the seasons were associated with the seeming approach and +recession of the sun. This observation, however, could not have +been made until man had migrated from the tropical regions, and +had reached a stage of mechanical development enabling him to +live in subtropical or temperate zones. Even then it is +conceivable that a long period must have elapsed before a direct +causal relation was felt to exist between the shifting of the sun +and the shifting of the seasons; because, as every one knows, the +periods of greatest heat in summer and greatest cold in winter +usually come some weeks after the time of the solstices. Yet, the +fact that these extremes of temperature are associated in some +way with the change of the sun's place in the heavens must, in +time, have impressed itself upon even a rudimentary intelligence. +It is hardly necessary to add that this is not meant to imply any +definite knowledge of the real meaning of, the seeming +oscillations of the sun. We shall see that, even at a relatively +late period, the vaguest notions were still in vogue as to the +cause of the sun's changes of position. + +That the sun, moon, and stars move across the heavens must +obviously have been among the earliest scientific observations. +It must not be inferred, however, that this observation implied a +necessary conception of the complete revolution of these bodies +about the earth. It is unnecessary to speculate here as to how +the primitive intelligence conceived the transfer of the sun from +the western to the eastern horizon, to be effected each night, +for we shall have occasion to examine some historical +speculations regarding this phenomenon. We may assume, however, +that the idea of the transfer of the heavenly bodies beneath the +earth (whatever the conception as to the form of that body) must +early have presented itself. + +It required a relatively high development of the observing +faculties, yet a development which man must have attained ages +before the historical period, to note that the moon has a +secondary motion, which leads it to shift its relative position +in the heavens, as regards the stars; that the stars themselves, +on the other hand, keep a fixed relation as regards one another, +with the notable exception of two or three of the most brilliant +members of the galaxy, the latter being the bodies which came to +be known finally as planets, or wandering stars. The wandering +propensities of such brilliant bodies as Jupiter and Venus cannot +well have escaped detection. We may safely assume, however, that +these anomalous motions of the moon and planets found no +explanation that could be called scientific until a relatively +late period. + +3. Turning from the heavens to the earth, and ignoring such +primitive observations as that of the distinction between land +and water, we may note that there was one great scientific law +which must have forced itself upon the attention of primitive +man. This is the law of universal terrestrial gravitation. The +word gravitation suggests the name of Newton, and it may excite +surprise to hear a knowledge of gravitation ascribed to men who +preceded that philosopher by, say, twenty-five or fifty thousand +years. Yet the slightest consideration of the facts will make it +clear that the great central law that all heavy bodies fall +directly towards the earth, cannot have escaped the attention of +the most primitive intelligence. The arboreal habits of our +primitive ancestors gave opportunities for constant observation +of the practicalities of this law. And, so soon as man had +developed the mental capacity to formulate ideas, one of the +earliest ideas must have been the conception, however vaguely +phrased in words, that all unsupported bodies fall towards the +earth. The same phenomenon being observed to operate on +water-surfaces, and no alteration being observed in its operation +in different portions of man's habitat, the most primitive +wanderer must have come to have full faith in the universal +action of the observed law of gravitation. Indeed, it is +inconceivable that he can have imagined a place on the earth +where this law does not operate. On the other hand, of course, he +never grasped the conception of the operation of this law beyond +the close proximity of the earth. To extend the reach of +gravitation out to the moon and to the stars, including within +its compass every particle of matter in the universe, was the +work of Newton, as we shall see in due course. Meantime we shall +better understand that work if we recall that the mere local fact +of terrestrial gravitation has been the familiar knowledge of all +generations of men. It may further help to connect us in sympathy +with our primeval ancestor if we recall that in the attempt to +explain this fact of terrestrial gravitation Newton made no +advance, and we of to-day are scarcely more enlightened than the +man of the Stone Age. Like the man of the Stone Age, we know that +an arrow shot into the sky falls back to the earth. We can +calculate, as he could not do, the arc it will describe and the +exact speed of its fall; but as to why it returns to earth at +all, the greatest philosopher of to-day is almost as much in the +dark as was the first primitive bowman that ever made the +experiment. + +Other physical facts going to make up an elementary science of +mechanics, that were demonstratively known to prehistoric man, +were such as these: the rigidity of solids and the mobility of +liquids; the fact that changes of temperature transform solids to +liquids and vice versa--that heat, for example, melts copper and +even iron, and that cold congeals water; and the fact that +friction, as illustrated in the rubbing together of two sticks, +may produce heat enough to cause a fire. The rationale of this +last experiment did not receive an explanation until about the +beginning of the nineteenth century of our own era. But the +experimental fact was so well known to prehistoric man that he +employed this method, as various savage tribes employ it to this +day, for the altogether practical purpose of making a fire; just +as he employed his practical knowledge of the mutability of +solids and liquids in smelting ores, in alloying copper with tin +to make bronze, and in casting this alloy in molds to make +various implements and weapons. Here, then, were the germs of an +elementary science of physics. Meanwhile such observations as +that of the solution of salt in water may be considered as giving +a first lesson in chemistry, but beyond such altogether +rudimentary conceptions chemical knowledge could not have +gone--unless, indeed, the practical observation of the effects of +fire be included; nor can this well be overlooked, since scarcely +another single line of practical observation had a more direct +influence in promoting the progress of man towards the heights of +civilization. + +4. In the field of what we now speak of as biological knowledge, +primitive man had obviously the widest opportunity for practical +observation. We can hardly doubt that man attained, at an early +day, to that conception of identity and of difference which Plato +places at the head of his metaphysical system. We shall urge +presently that it is precisely such general ideas as these that +were man's earliest inductions from observation, and hence that +came to seem the most universal and "innate" ideas of his +mentality. It is quite inconceivable, for example, that even the +most rudimentary intelligence that could be called human could +fail to discriminate between living things and, let us say, the +rocks of the earth. The most primitive intelligence, then, must +have made a tacit classification of the natural objects about it +into the grand divisions of animate and inanimate nature. +Doubtless the nascent scientist may have imagined life animating +many bodies that we should call inanimate--such as the sun, +wandering planets, the winds, and lightning; and, on the other +hand, he may quite likely have relegated such objects as trees to +the ranks of the non-living; but that he recognized a fundamental +distinction between, let us say, a wolf and a granite bowlder we +cannot well doubt. A step beyond this--a step, however, that may +have required centuries or millenniums in the taking--must have +carried man to a plane of intelligence from which a primitive +Aristotle or Linnaeus was enabled to note differences and +resemblances connoting such groups of things as fishes, birds, +and furry beasts. This conception, to be sure, is an abstraction +of a relatively high order. We know that there are savage races +to-day whose language contains no word for such an abstraction as +bird or tree. We are bound to believe, then, that there were long +ages of human progress during which the highest man had attained +no such stage of abstraction; but, on the other hand, it is +equally little in question that this degree of mental development +had been attained long before the opening of our historical +period. The primeval man, then, whose scientific knowledge we are +attempting to predicate, had become, through his conception of +fishes, birds, and hairy animals as separate classes, a +scientific zoologist of relatively high attainments. + +In the practical field of medical knowledge, a certain stage of +development must have been reached at a very early day. Even +animals pick and choose among the vegetables about them, and at +times seek out certain herbs quite different from their ordinary +food, practising a sort of instinctive therapeutics. The cat's +fondness for catnip is a case in point. The most primitive man, +then, must have inherited a racial or instinctive knowledge of +the medicinal effects of certain herbs; in particular he must +have had such elementary knowledge of toxicology as would enable +him to avoid eating certain poisonous berries. Perhaps, indeed, +we are placing the effect before the cause to some extent; for, +after all, the animal system possesses marvellous powers of +adaption, and there is perhaps hardly any poisonous vegetable +which man might not have learned to eat without deleterious +effect, provided the experiment were made gradually. To a certain +extent, then, the observed poisonous effects of numerous plants +upon the human system are to be explained by the fact that our +ancestors have avoided this particular vegetable. Certain fruits +and berries might have come to have been a part of man's diet, +had they grown in the regions he inhabited at an early day, which +now are poisonous to his system. This thought, however, carries +us too far afield. For practical purposes, it suffices that +certain roots, leaves, and fruits possess principles that are +poisonous to the human system, and that unless man had learned in +some way to avoid these, our race must have come to disaster. In +point of fact, he did learn to avoid them; and such evidence +implied, as has been said, an elementary knowledge of toxicology. + +Coupled with this knowledge of things dangerous to the human +system, there must have grown up, at a very early day, a belief +in the remedial character of various vegetables as agents to +combat disease. Here, of course, was a rudimentary therapeutics, +a crude principle of an empirical art of medicine. As just +suggested, the lower order of animals have an instinctive +knowledge that enables them to seek out remedial herbs (though we +probably exaggerate the extent of this instinctive knowledge); +and if this be true, man must have inherited from his prehuman +ancestors this instinct along with the others. That he extended +this knowledge through observation and practice, and came early +to make extensive use of drugs in the treatment of disease, is +placed beyond cavil through the observation of the various +existing barbaric tribes, nearly all of whom practice elaborate +systems of therapeutics. We shall have occasion to see that even +within historic times the particular therapeutic measures +employed were often crude, and, as we are accustomed to say, +unscientific; but even the crudest of them are really based upon +scientific principles, inasmuch as their application implies the +deduction of principles of action from previous observations. +Certain drugs are applied to appease certain symptoms of disease +because in the belief of the medicine-man such drugs have proved +beneficial in previous similar cases. + +All this, however, implies an appreciation of the fact that man +is subject to "natural" diseases, and that if these diseases are +not combated, death may result. But it should be understood that +the earliest man probably had no such conception as this. +Throughout all the ages of early development, what we call +"natural" disease and "natural" death meant the onslaught of a +tangible enemy. A study of this question leads us to some very +curious inferences. The more we look into the matter the more the +thought forces itself home to us that the idea of natural death, +as we now conceive it, came to primitive man as a relatively late +scientific induction. This thought seems almost startling, so +axiomatic has the conception "man is mortal" come to appear. Yet +a study of the ideas of existing savages, combined with our +knowledge of the point of view from which historical peoples +regard disease, make it more probable that the primitive +conception of human life did not include the idea of necessary +death. We are told that the Australian savage who falls from a +tree and breaks his neck is not regarded as having met a natural +death, but as having been the victim of the magical practices of +the "medicine-man" of some neighboring tribe. Similarly, we shall +find that the Egyptian and the Babylonian of the early historical +period conceived illness as being almost invariably the result of +the machinations of an enemy. One need but recall the +superstitious observances of the Middle Ages, and the yet more +recent belief in witchcraft, to realize how generally disease has +been personified as a malicious agent invoked by an unfriendly +mind. Indeed, the phraseology of our present-day speech is still +reminiscent of this; as when, for example, we speak of an "attack +of fever," and the like. + +When, following out this idea, we picture to ourselves the +conditions under which primitive man lived, it will be evident at +once how relatively infrequent must have been his observation of +what we usually term natural death. His world was a world of +strife; he lived by the chase; he saw animals kill one another; +he witnessed the death of his own fellows at the hands of +enemies. Naturally enough, then, when a member of his family was +"struck down" by invisible agents, he ascribed this death also to +violence, even though the offensive agent was concealed. +Moreover, having very little idea of the lapse of time--being +quite unaccustomed, that is, to reckon events from any fixed +era--primitive man cannot have gained at once a clear conception +of age as applied to his fellows. Until a relatively late stage +of development made tribal life possible, it cannot have been +usual for man to have knowledge of his grandparents; as a rule he +did not know his own parents after he had passed the adolescent +stage and had been turned out upon the world to care for himself. +If, then, certain of his fellow-beings showed those evidences of +infirmity which we ascribe to age, it did not necessarily follow +that he saw any association between such infirmities and the +length of time which those persons had lived. The very fact that +some barbaric nations retain the custom of killing the aged and +infirm, in itself suggests the possibility that this custom arose +before a clear conception had been attained that such drags upon +the community would be removed presently in the natural order of +things. To a person who had no clear conception of the lapse of +time and no preconception as to the limited period of man's life, +the infirmities of age might very naturally be ascribed to the +repeated attacks of those inimical powers which were understood +sooner or later to carry off most members of the race. And +coupled with this thought would go the conception that inasmuch +as some people through luck had escaped the vengeance of all +their enemies for long periods, these same individuals might +continue to escape for indefinite periods of the future. There +were no written records to tell primeval man of events of long +ago. He lived in the present, and his sweep of ideas scarcely +carried him back beyond the limits of his individual memory. But +memory is observed to be fallacious. It must early have been +noted that some people recalled events which other participants +in them had quite forgotten, and it may readily enough have been +inferred that those members of the tribe who spoke of events +which others could not recall were merely the ones who were +gifted with the best memories. If these reached a period when +their memories became vague, it did not follow that their +recollections had carried them back to the beginnings of their +lives. Indeed, it is contrary to all experience to believe that +any man remembers all the things he has once known, and the +observed fallaciousness and evanescence of memory would thus tend +to substantiate rather than to controvert the idea that various +members of a tribe had been alive for an indefinite period. + +Without further elaborating the argument, it seems a justifiable +inference that the first conception primitive man would have of +his own life would not include the thought of natural death, but +would, conversely, connote the vague conception of endless life. +Our own ancestors, a few generations removed, had not got rid of +this conception, as the perpetual quest of the spring of eternal +youth amply testifies. A naturalist of our own day has suggested +that perhaps birds never die except by violence. The thought, +then, that man has a term of years beyond which "in the nature of +things," as the saying goes, he may not live, would have dawned +but gradually upon the developing intelligence of successive +generations of men; and we cannot feel sure that he would fully +have grasped the conception of a "natural" termination of human +life until he had shaken himself free from the idea that disease +is always the result of the magic practice of an enemy. Our +observation of historical man in antiquity makes it somewhat +doubtful whether this conception had been attained before the +close of the prehistoric period. If it had, this conception of +the mortality of man was one of the most striking scientific +inductions to which prehistoric man attained. Incidentally, it +may be noted that the conception of eternal life for the human +body being a more primitive idea than the conception of natural +death, the idea of the immortality of the spirit would be the +most natural of conceptions. The immortal spirit, indeed, would +be but a correlative of the immortal body, and the idea which we +shall see prevalent among the Egyptians that the soul persists +only as long as the body is intact--the idea upon which the +practice of mummifying the dead depended--finds a ready +explanation. But this phase of the subject carries us somewhat +afield. For our present purpose it suffices to have pointed out +that the conception of man's mortality--a conception which now +seems of all others the most natural and "innate"--was in all +probability a relatively late scientific induction of our +primitive ancestors. + +5. Turning from the consideration of the body to its mental +complement, we are forced to admit that here, also, our primitive +man must have made certain elementary observations that underlie +such sciences as psychology, mathematics, and political economy. +The elementary emotions associated with hunger and with satiety, +with love and with hatred, must have forced themselves upon the +earliest intelligence that reached the plane of conscious +self-observation. The capacity to count, at least to the number +four or five, is within the range of even animal intelligence. +Certain savages have gone scarcely farther than this; but our +primeval ancestor, who was forging on towards civilization, had +learned to count his fingers and toes, and to number objects +about him by fives and tens in consequence, before be passed +beyond the plane of numerous existing barbarians. How much beyond +this he had gone we need not attempt to inquire; but the +relatively high development of mathematics in the early +historical period suggests that primeval man had attained a not +inconsiderable knowledge of numbers. The humdrum vocation of +looking after a numerous progeny must have taught the mother the +rudiments of addition and subtraction; and the elements of +multiplication and division are implied in the capacity to carry +on even the rudest form of barter, such as the various tribes +must have practised from an early day. + +As to political ideas, even the crudest tribal life was based on +certain conceptions of ownership, at least of tribal ownership, +and the application of the principle of likeness and difference +to which we have already referred. Each tribe, of course, +differed in some regard from other tribes, and the recognition of +these differences implied in itself a political classification. A +certain tribe took possession of a particular hunting- ground, +which became, for the time being, its home, and over which it +came to exercise certain rights. An invasion of this territory by +another tribe might lead to war, and the banding together of the +members of the tribe to repel the invader implied both a +recognition of communal unity and a species of prejudice in favor +of that community that constituted a primitive patriotism. But +this unity of action in opposing another tribe would not prevent +a certain rivalry of interest between the members of the same +tribe, which would show itself more and more prominently as the +tribe increased in size. The association of two or more persons +implies, always, the ascendency of some and the subordination of +others. Leadership and subordination are necessary correlatives +of difference of physical and mental endowment, and rivalry +between leaders would inevitably lead to the formation of +primitive political parties. With the ultimate success and +ascendency of one leader, who secures either absolute power or +power modified in accordance with the advice of subordinate +leaders, we have the germs of an elaborate political system--an +embryo science of government. + +Meanwhile, the very existence of such a community implies the +recognition on the part of its members of certain individual +rights, the recognition of which is essential to communal +harmony. The right of individual ownership of the various +articles and implements of every-day life must be recognized, or +all harmony would be at an end. Certain rules of justice-- +primitive laws--must, by common consent, give protection to the +weakest members of the community. Here are the rudiments of a +system of ethics. It may seem anomalous to speak of this +primitive morality, this early recognition of the principles of +right and wrong, as having any relation to science. Yet, rightly +considered, there is no incongruity in such a citation. There +cannot well be a doubt that the adoption of those broad +principles of right and wrong which underlie the entire structure +of modern civilization was due to scientific induction,--in other +words, to the belief, based on observation and experience, that +the principles implied were essential to communal progress. He +who has scanned the pageant of history knows how often these +principles seem to be absent in the intercourse of men and +nations. Yet the ideal is always there as a standard by which all +deeds are judged. + + +It would appear, then, that the entire superstructure of later +science had its foundation in the knowledge and practice of +prehistoric man. The civilization of the historical period could +not have advanced as it has had there not been countless +generations of culture back of it. The new principles of science +could not have been evolved had there not been great basal +principles which ages of unconscious experiment had impressed +upon the mind of our race. Due meed of praise must be given, +then, to our primitive ancestor for his scientific +accomplishments; but justice demands that we should look a little +farther and consider the reverse side of the picture. We have had +to do, thus far, chiefly with the positive side of +accomplishment. We have pointed out what our primitive ancestor +knew, intimating, perhaps, the limitations of his knowledge; but +we have had little to say of one all-important feature of his +scientific theorizing. The feature in question is based on the +highly scientific desire and propensity to find explanations for +the phenomena of nature. Without such desire no progress could be +made. It is, as we have seen, the generalizing from experience +that constitutes real scientific progress; and yet, just as most +other good things can be overdone, this scientific propensity may +be carried to a disastrous excess. + +Primeval man did not escape this danger. He observed, he +reasoned, he found explanations; but he did not always +discriminate as to the logicality of his reasonings. He failed to +recognize the limitations of his knowledge. The observed +uniformity in the sequence of certain events impressed on his +mind the idea of cause and effect. Proximate causes known, he +sought remoter causes; childlike, his inquiring mind was always +asking, Why? and, childlike, he demanded an explicit answer. If +the forces of nature seemed to combat him, if wind and rain +opposed his progress and thunder and lightning seemed to menace +his existence, he was led irrevocably to think of those human +foes who warred with him, and to see, back of the warfare of the +elements, an inscrutable malevolent intelligence which took this +method to express its displeasure. But every other line of +scientific observation leads equally, following back a sequence +of events, to seemingly causeless beginnings. Modern science can +explain the lightning, as it can explain a great number of the +mysteries which the primeval intelligence could not penetrate. +But the primordial man could not wait for the revelations of +scientific investigation: he must vault at once to a final +solution of all scientific problems. He found his solution by +peopling the world with invisible forces, anthropomorphic in +their conception, like himself in their thought and action, +differing only in the limitations of their powers. His own dream +existence gave him seeming proof of the existence of an alter +ego, a spiritual portion of himself that could dissever itself +from his body and wander at will; his scientific inductions +seemed to tell him of a world of invisible beings, capable of +influencing him for good or ill. From the scientific exercise of +his faculties he evolved the all-encompassing generalizations of +invisible and all-powerful causes back of the phenomena of +nature. These generalizations, early developed and seemingly +supported by the observations of countless generations, came to +be among the most firmly established scientific inductions of our +primeval ancestor. They obtained a hold upon the mentality of our +race that led subsequent generations to think of them, sometimes +to speak of them, as "innate" ideas. The observations upon which +they were based are now, for the most part, susceptible of other +interpretations; but the old interpretations have precedent and +prejudice back of them, and they represent ideas that are more +difficult than almost any others to eradicate. Always, and +everywhere, superstitions based upon unwarranted early scientific +deductions have been the most implacable foes to the progress of +science. Men have built systems of philosophy around their +conception of anthropomorphic deities; they have linked to these +systems of philosophy the allied conception of the immutability +of man's spirit, and they have asked that scientific progress +should stop short at the brink of these systems of philosophy and +accept their dictates as final. Yet there is not to-day in +existence, and there never has been, one jot of scientific +evidence for the existence of these intangible anthropomorphic +powers back of nature that is not susceptible of scientific +challenge and of more logical interpretation. In despite of which +the superstitious beliefs are still as firmly fixed in the minds +of a large majority of our race as they were in the mind of our +prehistoric ancestor. The fact of this baleful heritage must not +be forgotten in estimating the debt of gratitude which historic +man owes to his barbaric predecessor. + + + +II. EGYPTIAN SCIENCE + +In the previous chapter we have purposely refrained from +referring to any particular tribe or race of historical man. Now, +however, we are at the beginnings of national existence, and we +have to consider the accomplishments of an individual race; or +rather, perhaps, of two or more races that occupied successively +the same geographical territory. But even now our studies must +for a time remain very general; we shall see little or nothing of +the deeds of individual scientists in the course of our study of +Egyptian culture. We are still, it must be understood, at the +beginnings of history; indeed, we must first bridge over the gap +from the prehistoric before we may find ourselves fairly on the +line of march of historical science. + +At the very outset we may well ask what constitutes the +distinction between prehistoric and historic epochs --a +distinction which has been constantly implied in much that we +have said. The reply savors somewhat of vagueness. It is a +distinction having to do, not so much with facts of human +progress as with our interpretation of these facts. When we speak +of the dawn of history we must not be understood to imply that, +at the period in question, there was any sudden change in the +intellectual status of the human race or in the status of any +individual tribe or nation of men. What we mean is that modern +knowledge has penetrated the mists of the past for the period we +term historical with something more of clearness and precision +than it has been able to bring to bear upon yet earlier periods. +New accessions of knowledge may thus shift from time to time the +bounds of the so-called historical period. The clearest +illustration of this is furnished by our interpretation of +Egyptian history. Until recently the biblical records of the +Hebrew captivity or service, together with the similar account of +Josephus, furnished about all that was known of Egyptian history +even of so comparatively recent a time as that of Ramses II. +(fifteenth century B.C.), and from that period on there was +almost a complete gap until the story was taken up by the Greek +historians Herodotus and Diodorus. It is true that the king-lists +of the Alexandrian historian, Manetho, were all along accessible +in somewhat garbled copies. But at best they seemed to supply +unintelligible lists of names and dates which no one was disposed +to take seriously. That they were, broadly speaking, true +historical records, and most important historical records at +that, was not recognized by modern scholars until fresh light had +been thrown on the subject from altogether new sources. + +These new sources of knowledge of ancient history demand a +moment's consideration. They are all-important because they have +been the means of extending the historical period of Egyptian +history (using the word history in the way just explained) by +three or four thousand years. As just suggested, that historical +period carried the scholarship of the early nineteenth century +scarcely beyond the fifteenth century B.C., but to-day's vision +extends with tolerable clearness to about the middle of the fifth +millennium B.C. This change has been brought about chiefly +through study of the Egyptian hieroglyphics. These hieroglyphics +constitute, as we now know, a highly developed system of writing; +a system that was practised for some thousands of years, but +which fell utterly into disuse in the later Roman period, and the +knowledge of which passed absolutely from the mind of man. For +about two thousand years no one was able to read, with any degree +of explicitness, a single character of this strange script, and +the idea became prevalent that it did not constitute a real +system of writing, but only a more or less barbaric system of +religious symbolism. The falsity of this view was shown early in +the nineteenth century when Dr. Thomas Young was led, through +study of the famous trilingual inscription of the Rosetta stone, +to make the first successful attempt at clearing up the mysteries +of the hieroglyphics. + +This is not the place to tell the story of his fascinating +discoveries and those of his successors. That story belongs to +nineteenth-century science, not to the science of the Egyptians. +Suffice it here that Young gained the first clew to a few of the +phonetic values of the Egyptian symbols, and that the work of +discovery was carried on and vastly extended by the Frenchman +Champollion, a little later, with the result that the firm +foundations of the modern science of Egyptology were laid. +Subsequently such students as Rosellini the Italian, Lepsius the +German, and Wilkinson the Englishman, entered the field, which in +due course was cultivated by De Rouge in France and Birch in +England, and by such distinguished latter-day workers as Chabas, +Mariette, Maspero, Amelineau, and De Morgan among the Frenchmen; +Professor Petrie and Dr. Budge in England; and Brugsch Pasha and +Professor Erman in Germany, not to mention a large coterie of +somewhat less familiar names. These men working, some of them in +the field of practical exploration, some as students of the +Egyptian language and writing, have restored to us a tolerably +precise knowledge of the history of Egypt from the time of the +first historical king, Mena, whose date is placed at about the +middle of the fifth century B.C. We know not merely the names of +most of the subsequent rulers, but some thing of the deeds of +many of them; and, what is vastly more important, we know, thanks +to the modern interpretation of the old literature, many things +concerning the life of the people, and in particular concerning +their highest culture, their methods of thought, and their +scientific attainments, which might well have been supposed to be +past finding out. Nor has modern investigation halted with the +time of the first kings; the recent explorations of such +archaeologists as Amelineau, De Morgan, and Petrie have brought +to light numerous remains of what is now spoken of as the +predynastic period--a period when the inhabitants of the Nile +Valley used implements of chipped stone, when their pottery was +made without the use of the potter's wheel, and when they buried +their dead in curiously cramped attitudes without attempt at +mummification. These aboriginal inhabitants of Egypt cannot +perhaps with strict propriety be spoken of as living within the +historical period, since we cannot date their relics with any +accuracy. But they give us glimpses of the early stages of +civilization upon which the Egyptians of the dynastic period were +to advance. + +It is held that the nascent civilization of these Egyptians of +the Neolithic, or late Stone Age, was overthrown by the invading +hosts of a more highly civilized race which probably came from +the East, and which may have been of a Semitic stock. The +presumption is that this invading people brought with it a +knowledge of the arts of war and peace, developed or adopted in +its old home. The introduction of these arts served to bridge +somewhat suddenly, so far as Egypt is concerned, that gap between +the prehistoric and the historic stage of culture to which we +have all along referred. The essential structure of that bridge, +let it now be clearly understood, consisted of a single element. +That element is the capacity to make written records: a knowledge +of the art of writing. Clearly understood, it is this element of +knowledge that forms the line bounding the historical period. +Numberless mementos are in existence that tell of the +intellectual activities of prehistoric man; such mementos as +flint implements, pieces of pottery, and fragments of bone, +inscribed with pictures that may fairly be spoken of as works of +art; but so long as no written word accompanies these records, so +long as no name of king or scribe comes down to us, we feel that +these records belong to the domain of archaeology rather than to +that of history. Yet it must be understood all along that these +two domains shade one into the other and, it has already been +urged, that the distinction between them is one that pertains +rather to modern scholarship than to the development of +civilization itself. Bearing this distinction still in mind, and +recalling that the historical period, which is to be the field of +our observation throughout the rest of our studies, extends for +Egypt well back into the fifth millennium B.C., let us briefly +review the practical phases of that civilization to which the +Egyptian had attained before the beginning of the dynastic +period. Since theoretical science is everywhere linked with the +mechanical arts, this survey will give us a clear comprehension +of the field that lies open for the progress of science in the +long stages of historical time upon which we are just entering. + +We may pass over such rudimentary advances in the direction of +civilization as are implied in the use of articulate language, +the application of fire to the uses of man, and the systematic +making of dwellings of one sort or another, since all of these +are stages of progress that were reached very early in the +prehistoric period. What more directly concerns us is to note +that a really high stage of mechanical development had been +reached before the dawnings of Egyptian history proper. All +manner of household utensils were employed; the potter's wheel +aided in the construction of a great variety of earthen vessels; +weaving had become a fine art, and weapons of bronze, including +axes, spears, knives, and arrow-heads, were in constant use. +Animals had long been domesticated, in particular the dog, the +cat, and the ox; the horse was introduced later from the East. +The practical arts of agriculture were practised almost as they +are at the present day in Egypt, there being, of course, the same +dependence then as now upon the inundations of the Nile. + +As to government, the Egyptian of the first dynasty regarded his +king as a demi-god to be actually deified after his death, and +this point of view was not changed throughout the stages of later +Egyptian history. In point of art, marvellous advances upon the +skill of the prehistoric man had been made, probably in part +under Asiatic influences, and that unique style of stilted yet +expressive drawing had come into vogue, which was to be +remembered in after times as typically Egyptian. More important +than all else, our Egyptian of the earliest historical period was +in possession of the art of writing. He had begun to make those +specific records which were impossible to the man of the Stone +Age, and thus he had entered fully upon the way of historical +progress which, as already pointed out, has its very foundation +in written records. From now on the deeds of individual kings +could find specific record. It began to be possible to fix the +chronology of remote events with some accuracy; and with this +same fixing of chronologies came the advent of true history. The +period which precedes what is usually spoken of as the first +dynasty in Egypt is one into which the present-day searcher is +still able to see but darkly. The evidence seems to suggest than +an invasion of relatively cultured people from the East +overthrew, and in time supplanted, the Neolithic civilization of +the Nile Valley. It is impossible to date this invasion +accurately, but it cannot well have been later than the year 5000 +B.C., and it may have been a great many centuries earlier than +this. Be the exact dates what they may, we find the Egyptian of +the fifth millennium B.C. in full possession of a highly +organized civilization. + +All subsequent ages have marvelled at the pyramids, some of which +date from about the year 4000 B.C., though we may note in passing +that these dates must not be taken too literally. The chronology +of ancient Egypt cannot as yet be fixed with exact accuracy, but +the disagreements between the various students of the subject +need give us little concern. For our present purpose it does not +in the least matter whether the pyramids were built three +thousand or four thousand years before the beginning of our era. +It suffices that they date back to a period long antecedent to +the beginnings of civilization in Western Europe. They prove that +the Egyptian of that early day had attained a knowledge of +practical mechanics which, even from the twentieth-century point +of view, is not to be spoken of lightly. It has sometimes been +suggested that these mighty pyramids, built as they are of great +blocks of stone, speak for an almost miraculous knowledge on the +part of their builders; but a saner view of the conditions gives +no warrant for this thought. Diodoras, the Sicilian, in his +famous World's History, written about the beginning of our era, +explains the building of the pyramids by suggesting that great +quantities of earth were piled against the side of the rising +structure to form an inclined plane up which the blocks of stone +were dragged. He gives us certain figures, based, doubtless, on +reports made to him by Egyptian priests, who in turn drew upon +the traditions of their country, perhaps even upon written +records no longer preserved. He says that one hundred and twenty +thousand men were employed in the construction of the largest +pyramid, and that, notwithstanding the size of this host of +workers, the task occupied twenty years. We must not place too +much dependence upon such figures as these, for the ancient +historians are notoriously given to exaggeration in recording +numbers; yet we need not doubt that the report given by Diodorus +is substantially accurate in its main outlines as to the method +through which the pyramids were constructed. A host of men +putting their added weight and strength to the task, with the aid +of ropes, pulleys, rollers, and levers, and utilizing the +principle of the inclined plane, could undoubtedly move and +elevate and place in position the largest blocks that enter into +the pyramids or--what seems even more wonderful--the most +gigantic obelisks, without the aid of any other kind of mechanism +or of any more occult power. The same hands could, as Diodorus +suggests, remove all trace of the debris of construction and +leave the pyramids and obelisks standing in weird isolation, as +if sprung into being through a miracle. + + +ASTRONOMICAL SCIENCE + +It has been necessary to bear in mind these phases of practical +civilization because much that we know of the purely scientific +attainments of the Egyptians is based upon modern observation of +their pyramids and temples. It was early observed, for example, +that the pyramids are obviously oriented as regards the direction +in which they face, in strict accordance with some astronomical +principle. Early in the nineteenth century the Frenchman Biot +made interesting studies in regard to this subject, and a hundred +years later, in our own time, Sir Joseph Norman Lockyer, +following up the work of various intermediary observers, has +given the subject much attention, making it the central theme of +his work on The Dawn of Astronomy.[1] Lockyer's researches make +it clear that in the main the temples of Egypt were oriented with +reference to the point at which the sun rises on the day of the +summer solstice. The time of the solstice had peculiar interest +for the Egyptians, because it corresponded rather closely with +the time of the rising of the Nile. The floods of that river +appear with very great regularity; the on-rushing tide reaches +the region of Heliopolis and Memphis almost precisely on the day +of the summer solstice. The time varies at different stages of +the river's course, but as the civilization of the early +dynasties centred at Memphis, observations made at this place had +widest vogue. + +Considering the all-essential character of the Nile +floods-without which civilization would be impossible in +Egypt--it is not strange that the time of their appearance should +be taken as marking the beginning of a new year. The fact that +their coming coincides with the solstice makes such a division of +the calendar perfectly natural. In point of fact, from the +earliest periods of which records have come down to us, the new +year of the Egyptians dates from the summer solstice. It is +certain that from the earliest historical periods the Egyptians +were aware of the approximate length of the year. It would be +strange were it otherwise, considering the ease with which a +record of days could be kept from Nile flood to Nile flood, or +from solstice to solstice. But this, of course, applies only to +an approximate count. There is some reason to believe that in the +earliest period the Egyptians made this count only 360 days. The +fact that their year was divided into twelve months of thirty +days each lends color to this belief; but, in any event, the +mistake was discovered in due time and a partial remedy was +applied through the interpolation of a "little month" of five +days between the end of the twelfth month and the new year. This +nearly but not quite remedied the matter. What it obviously +failed to do was to take account of that additional quarter of a +day which really rounds out the actual year. + +It would have been a vastly convenient thing for humanity had it +chanced that the earth had so accommodated its rotary motion with +its speed of transit about the sun as to make its annual flight +in precisely 360 days. Twelve lunar months of thirty days each +would then have coincided exactly with the solar year, and most +of the complexities of the calendar, which have so puzzled +historical students, would have been avoided; but, on the other +hand, perhaps this very simplicity would have proved detrimental +to astronomical science by preventing men from searching the +heavens as carefully as they have done. Be that as it may, the +complexity exists. The actual year of three hundred and +sixty-five and (about) one-quarter days cannot be divided evenly +into months, and some such expedient as the intercalation of days +here and there is essential, else the calendar will become +absolutely out of harmony with the seasons. + +In the case of the Egyptians, the attempt at adjustment was made, +as just noted, by the introduction of the five days, constituting +what the Egyptians themselves termed "the five days over and +above the year." These so-called epagomenal days were undoubtedly +introduced at a very early period. Maspero holds that they were +in use before the first Thinite dynasty, citing in evidence the +fact that the legend of Osiris explains these days as having been +created by the god Thot in order to permit Nuit to give birth to +all her children; this expedient being necessary to overcome a +ban which had been pronounced against Nuit, according to which +she could not give birth to children on any day of the year. But, +of course, the five additional days do not suffice fully to +rectify the calendar. There remains the additional quarter of a +day to be accounted for. This, of course, amounts to a full day +every fourth year. We shall see that later Alexandrian science +hit upon the expedient of adding a day to every fourth year; an +expedient which the Julian calendar adopted and which still gives +us our familiar leap-year. But, unfortunately, the ancient +Egyptian failed to recognize the need of this additional day, or +if he did recognize it he failed to act on his knowledge, and so +it happened that, starting somewhere back in the remote past with +a new year's day that coincided with the inundation of the Nile, +there was a constantly shifting maladjustment of calendar and +seasons as time went on. + +The Egyptian seasons, it should be explained, were three in +number: the season of the inundation, the season of the +seed-time, and the season of the harvest; each season being, of +course, four months in extent. Originally, as just mentioned, the +season of the inundations began and coincided with the actual +time of inundation. The more precise fixing of new year's day was +accomplished through observation of the time of the so-called +heliacal rising of the dog-star, Sirius, which bore the Egyptian +name Sothis. It chances that, as viewed from about the region of +Heliopolis, the sun at the time of the summer solstice occupies +an apparent position in the heavens close to the dog-star. Now, +as is well known, the Egyptians, seeing divinity back of almost +every phenomenon of nature, very naturally paid particular +reverence to so obviously influential a personage as the sun-god. +In particular they thought it fitting to do homage to him just as +he was starting out on his tour of Egypt in the morning; and that +they might know the precise moment of his coming, the Egyptian +astronomer priests, perched on the hill-tops near their temples, +were wont to scan the eastern horizon with reference to some star +which had been observed to precede the solar luminary. Of course +the precession of the equinoxes, due to that axial wobble in +which our clumsy earth indulges, would change the apparent +position of the fixed stars in reference to the sun, so that the +same star could not do service as heliacal messenger +indefinitely; but, on the other hand, these changes are so slow +that observations by many generations of astronomers would be +required to detect the shifting. It is believed by Lockyer, +though the evidence is not quite demonstrative, that the +astronomical observations of the Egyptians date back to a period +when Sothis, the dog-star, was not in close association with the +sun on the morning of the summer solstice. Yet, according to the +calculations of Biot, the heliacal rising of Sothis at the +solstice was noted as early as the year 3285 B.C., and it is +certain that this star continued throughout subsequent centuries +to keep this position of peculiar prestige. Hence it was that +Sothis came to be associated with Isis, one of the most important +divinities of Egypt, and that the day in which Sothis was first +visible in the morning sky marked the beginning of the new year; +that day coinciding, as already noted, with the summer solstice +and with the beginning of the Nile flow. + +But now for the difficulties introduced by that unreckoned +quarter of a day. Obviously with a calendar of 365 days only, at +the end of four years, the calendar year, or vague year, as the +Egyptians came to call it, had gained by one full day upon the +actual solar year-- that is to say, the heliacal rising of +Sothis, the dog- star, would not occur on new year's day of the +faulty calendar, but a day later. And with each succeeding period +of four years the day of heliacal rising, which marked the true +beginning of the year--and which still, of course, coincided with +the inundation--would have fallen another day behind the +calendar. In the course of 120 years an entire month would be +lost; and in 480 years so great would become the shifting that +the seasons would be altogether misplaced; the actual time of +inundations corresponding with what the calendar registered as +the seed-time, and the actual seed-time in turn corresponding +with the harvest-time of the calendar. + +At first thought this seems very awkward and confusing, but in +all probability the effects were by no means so much so in actual +practice. We need go no farther than to our own experience to +know that the names of seasons, as of months and days, come to +have in the minds of most of us a purely conventional +significance. Few of us stop to give a thought to the meaning of +the words January, February, etc., except as they connote certain +climatic conditions. If, then, our own calendar were so defective +that in the course of 120 years the month of February had shifted +back to occupy the position of the original January, the change +would have been so gradual, covering the period of two life-times +or of four or five average generations, that it might well escape +general observation. + +Each succeeding generation of Egyptians, then, may not improbably +have associated the names of the seasons with the contemporary +climatic conditions, troubling themselves little with the thought +that in an earlier age the climatic conditions for each period of +the calendar were quite different. We cannot well suppose, +however, that the astronomer priests were oblivious to the true +state of things. Upon them devolved the duty of predicting the +time of the Nile flood; a duty they were enabled to perform +without difficulty through observation of the rising of the +solstitial sun and its Sothic messenger. To these observers it +must finally have been apparent that the shifting of the seasons +was at the rate of one day in four years; this known, it required +no great mathematical skill to compute that this shifting would +finally effect a complete circuit of the calendar, so that after +(4 X 365 =) 1460 years the first day of the calendar year would +again coincide with the heliacal rising of Sothis and with the +coming of the Nile flood. In other words, 1461 vague years or +Egyptian calendar years Of 365 days each correspond to 1460 +actual solar years of 365 1/4 days each. This period, measured +thus by the heliacal rising of Sothis, is spoken of as the Sothic +cycle. + +To us who are trained from childhood to understand that the year +consists of (approximately) 365 1/4 days, and to know that the +calendar may be regulated approximately by the introduction of an +extra day every fourth year, this recognition of the Sothic cycle +seems simple enough. Yet if the average man of us will reflect +how little he knows, of his own knowledge, of the exact length of +the year, it will soon become evident that the appreciation of +the faults of the calendar and the knowledge of its periodical +adjustment constituted a relatively high development of +scientific knowledge on the part of the Egyptian astronomer. It +may be added that various efforts to reform the calendar were +made by the ancient Egyptians, but that they cannot be credited +with a satisfactory solution of the problem; for, of course, the +Alexandrian scientists of the Ptolemaic period (whose work we +shall have occasion to review presently) were not Egyptians in +any proper sense of the word, but Greeks. + +Since so much of the time of the astronomer priests was devoted +to observation of the heavenly bodies, it is not surprising that +they should have mapped out the apparent course of the moon and +the visible planets in their nightly tour of the heavens, and +that they should have divided the stars of the firmament into +more or less arbitrary groups or constellations. That they did so +is evidenced by various sculptured representations of +constellations corresponding to signs of the zodiac which still +ornament the ceilings of various ancient temples. Unfortunately +the decorative sense, which was always predominant with the +Egyptian sculptor, led him to take various liberties with the +distribution of figures in these representations of the +constellations, so that the inferences drawn from them as to the +exact map of the heavens as the Egyptians conceived it cannot be +fully relied upon. It appears, however, that the Egyptian +astronomer divided the zodiac into twenty-four decani, or +constellations. The arbitrary groupings of figures, with the aid +of which these are delineated, bear a close resemblance to the +equally arbitrary outlines which we are still accustomed to use +for the same purpose. + + +IDEAS OF COSMOLOGY + +In viewing this astronomical system of the Egyptians one cannot +avoid the question as to just what interpretation was placed upon +it as regards the actual mechanical structure of the universe. A +proximal answer to the question is supplied us with a good deal +of clearness. It appears that the Egyptian conceived the sky as a +sort of tangible or material roof placed above the world, and +supported at each of its four corners by a column or pillar, +which was later on conceived as a great mountain. The earth +itself was conceived to be a rectangular box, longer from north +to south than from east to west; the upper surface of this box, +upon which man lived, being slightly concave and having, of +course, the valley of the Nile as its centre. The pillars of +support were situated at the points of the compass; the northern +one being located beyond the Mediterranean Sea; the southern one +away beyond the habitable regions towards the source of the Nile, +and the eastern and western ones in equally inaccessible regions. +Circling about the southern side of the, world was a great river +suspended in mid-air on something comparable to mountain cliffs; +on which river the sun-god made his daily course in a boat, +fighting day by day his ever-recurring battle against Set, the +demon of darkness. The wide channel of this river enabled the +sun-god to alter his course from time to time, as he is observed +to do; in winter directing his bark towards the farther bank of +the channel; in summer gliding close to the nearer bank. As to +the stars, they were similar lights, suspended from the vault of +the heaven; but just how their observed motion of translation +across the heavens was explained is not apparent. It is more than +probable that no one explanation was, universally accepted. + +In explaining the origin of this mechanism of the heavens, the +Egyptian imagination ran riot. Each separate part of Egypt had +its own hierarchy of gods, and more or less its own explanations +of cosmogony. There does not appear to have been any one central +story of creation that found universal acceptance, any more than +there was one specific deity everywhere recognized as supreme +among the gods. Perhaps the most interesting of the cosmogonic +myths was that which conceived that Nuit, the goddess of night, +had been torn from the arms of her husband, Sibu the earth-god, +and elevated to the sky despite her protests and her husband's +struggles, there to remain supported by her four limbs, which +became metamorphosed into the pillars, or mountains, already +mentioned. The forcible elevation of Nuit had been effected on +the day of creation by a new god, Shu, who came forth from the +primeval waters. A painting on the mummy case of one Betuhamon, +now in the Turin Museum, illustrates, in the graphic manner so +characteristic of the Egyptians, this act of creation. As +Maspero[2] points out, the struggle of Sibu resulted in +contorted attitudes to which the irregularities of the earth's +surface are to be ascribed. + +In contemplating such a scheme of celestial mechanics as that +just outlined, one cannot avoid raising the question as to just +the degree of literalness which the Egyptians themselves put upon +it. We know how essentially eye-minded the Egyptian was, to use a +modern psychological phrase--that is to say, how essential to him +it seemed that all his conceptions should be visualized. The +evidences of this are everywhere: all his gods were made +tangible; he believed in the immortality of the soul, yet he +could not conceive of such immortality except in association with +an immortal body; he must mummify the body of the dead, else, as +he firmly believed, the dissolution of the spirit would take +place along with the dissolution of the body itself. His world +was peopled everywhere with spirits, but they were spirits +associated always with corporeal bodies; his gods found lodgment +in sun and moon and stars; in earth and water; in the bodies of +reptiles and birds and mammals. He worshipped all of these +things: the sun, the moon, water, earth, the spirit of the Nile, +the ibis, the cat, the ram, and apis the bull; but, so far as we +can judge, his imagination did not reach to the idea of an +absolutely incorporeal deity. Similarly his conception of the +mechanism of the heavens must be a tangibly mechanical one. He +must think of the starry firmament as a substantial entity which +could not defy the law of gravitation, and which, therefore, must +have the same manner of support as is required by the roof of a +house or temple. We know that this idea of the materiality of the +firmament found elaborate expression in those later cosmological +guesses which were to dominate the thought of Europe until the +time of Newton. We need not doubt, therefore, that for the +Egyptian this solid vault of the heavens had a very real +existence. If now and then some dreamer conceived the great +bodies of the firmament as floating in a less material +plenum--and such iconoclastic dreamers there are in all ages--no +record of his musings has come down to us, and we must freely +admit that if such thoughts existed they were alien to the +character of the Egyptian mind as a whole. + +While the Egyptians conceived the heavenly bodies as the +abiding-place of various of their deities, it does not appear +that they practised astrology in the later acceptance of that +word. This is the more remarkable since the conception of lucky +and unlucky days was carried by the Egyptians to the extremes of +absurdity. "One day was lucky or unlucky," says Erman,[3] +"according as a good or bad mythological incident took place on +that day. For instance, the 1st of Mechir, on which day the sky +was raised, and the 27th of Athyr, when Horus and, Set concluded +peace together and divided the world between them, were lucky +days; on the other hand, the 14th of Tybi, on which Isis and +Nephthys mourned for Osiris, was an unlucky day. With the unlucky +days, which, fortunately, were less in number than the lucky +days, they distinguished different degrees of ill-luck. Some were +very unlucky, others only threatened ill-luck, and many, like the +17th and the 27th Choiakh, were partly good and partly bad +according to the time of day. Lucky days might, as a rule, be +disregarded. At most it might be as well to visit some specially +renowned temple, or to 'celebrate a joyful day at home,' but no +particular precautions were really necessary; and, above all, it +was said, 'what thou also seest on the day is lucky.' It was +quite otherwise with the unlucky and dangerous days, which +imposed so many and such great limitations on people that those +who wished to be prudent were always obliged to bear them in mind +when determining on any course of action. Certain conditions were +easy to carry out. Music and singing were to be avoided on the +14th Tybi, the day of the mourning of Osiris, and no one was +allowed to wash on the 16th Tybi; whilst the name of Set might +not be pronounced on the 24th of Pharmuthi. Fish was forbidden on +certain days; and what was still more difficult in a country so +rich in mice, on the 12th of Tybi no mouse might be seen. The +most tiresome prohibitions, however, were those which occurred +not infrequently, namely, those concerning work and going out: +for instance, four times in Paophi the people had to 'do nothing +at all,' and five times to sit the whole day or half the day in +the house; and the same rule had to be observed each month. It +was impossible to rejoice if a child was born on the 23d of +Thoth; the parents knew it could not live. Those born on the 20th +of Choiakh would become blind, and those born on the 3d of +Choiakh, deaf." + + +CHARMS AND INCANTATIONS + +Where such conceptions as these pertained, it goes without saying +that charms and incantations intended to break the spell of the +unlucky omens were equally prevalent. Such incantations consisted +usually of the recitation of certain phrases based originally, it +would appear, upon incidents in the history of the gods. The +words which the god had spoken in connection with some lucky +incident would, it was thought, prove effective now in bringing +good luck to the human supplicant--that is to say, the magician +hoped through repeating the words of the god to exercise the +magic power of the god. It was even possible, with the aid of the +magical observances, partly to balk fate itself. Thus the person +predestined through birth on an unlucky day to die of a serpent +bite might postpone the time of this fateful visitation to +extreme old age. The like uncertainty attached to those spells +which one person was supposed to be able to exercise over +another. It was held, for example, that if something belonging to +an individual, such as a lock of hair or a paring of the nails, +could be secured and incorporated in a waxen figure, this figure +would be intimately associated with the personality of that +individual. An enemy might thus secure occult power over one; any +indignity practised upon the waxen figure would result in like +injury to its human prototype. If the figure were bruised or +beaten, some accident would overtake its double; if the image +were placed over a fire, the human being would fall into a fever, +and so on. But, of course, such mysterious evils as these would +be met and combated by equally mysterious processes; and so it +was that the entire art of medicine was closely linked with +magical practices. It was not, indeed, held, according to +Maspero, that the magical spells of enemies were the sole sources +of human ailments, but one could never be sure to what extent +such spells entered into the affliction; and so closely were the +human activities associated in the mind of the Egyptian with one +form or another of occult influences that purely physical +conditions were at a discount. In the later times, at any rate, +the physician was usually a priest, and there was a close +association between the material and spiritual phases of +therapeutics. Erman[4] tells us that the following formula had to +be recited at the preparation of all medicaments: "That Isis +might make free, make free. That Isis might make Horus free from +all evil that his brother Set had done to him when he slew his +father, Osiris. O Isis, great enchantress, free me, release me +from all evil red things, from the fever of the god, and the +fever of the goddess, from death and death from pain, and the +pain which comes over me; as thou hast freed, as thou hast +released thy son Horus, whilst I enter into the fire and come +forth from the water," etc. Again, when the invalid took the +medicine, an incantation had to be said which began thus: "Come +remedy, come drive it out of my heart, out of these limbs strong +in magic power with the remedy." He adds: "There may have been a +few rationalists amongst the Egyptian doctors, for the number of +magic formulae varies much in the different books. The book that +we have specially taken for a foundation for this account of +Egyptian medicine-- the great papyrus of the eighteenth dynasty +edited by Ebers[5]--contains, for instance, far fewer exorcisms +than some later writings with similar contents, probably because +the doctor who compiled this book of recipes from older sources +had very little liking for magic." + +It must be understood, however--indeed, what has just been said +implies as much--that the physician by no means relied upon +incantations alone; on the contrary, he equipped himself with an +astonishing variety of medicaments. He had a particular fondness +for what the modern physician speaks of as a "shot-gun" +prescription--one containing a great variety of ingredients. Not +only did herbs of many kinds enter into this, but such substances +as lizard's blood, the teeth of swine, putrid meat, the moisture +from pigs' ears, boiled horn, and numerous other even more +repellent ingredients. Whoever is familiar with the formulae +employed by European physicians even so recently as the +eighteenth century will note a striking similarity here. Erman +points out that the modern Egyptian even of this day holds +closely to many of the practices of his remote ancestor. In +particular, the efficacy of the beetle as a medicinal agent has +stood the test of ages of practice. "Against all kinds of +witchcraft," says an ancient formula, "a great scarabaeus beetle; +cut off his head and wings, boil him; put him in oil and lay him +out; then cook his head and wings, put them in snake fat, boil, +and let the patient drink the mixture." The modern Egyptian, says +Erman, uses almost precisely the same recipe, except that the +snake fat is replaced by modern oil. + +In evidence of the importance which was attached to practical +medicine in the Egypt of an early day, the names of several +physicians have come down to us from an age which has preserved +very few names indeed, save those of kings. In reference to this +Erman says[6]: "We still know the names of some of the early body +physicians of this time; Sechmetna'eonch, 'chief physician of the +Pharaoh,' and Nesmenan his chief, the 'superintendent of the +physicians of the Pharaoh.' The priests also of the +lioness-headed goddess Sechmet seem to have been famed for their +medical wisdom, whilst the son of this goddess, the demi-god +Imhotep, was in later times considered to be the creator of +medical knowledge. These ancient doctors of the New Empire do not +seem to have improved upon the older conceptions about the +construction of the human body." + +As to the actual scientific attainments of the Egyptian +physician, it is difficult to speak with precision. Despite the +cumbersome formulae and the grotesque incantations, we need not +doubt that a certain practical value attended his therapeutics. +He practised almost pure empiricism, however, and certainly it +must have been almost impossible to determine which ones, if any, +of the numerous ingredients of the prescription had real +efficacy. + +The practical anatomical knowledge of the physician, there is +every reason to believe, was extremely limited. At first thought +it might seem that the practice of embalming would have led to +the custom of dissecting human bodies, and that the Egyptians, as +a result of this, would have excelled in the knowledge of +anatomy. But the actual results were rather the reverse of this. +Embalming the dead, it must be recalled, was a purely religious +observance. It took place under the superintendence of the +priests, but so great was the reverence for the human body that +the priests themselves were not permitted to make the abdominal +incision which was a necessary preliminary of the process. This +incision, as we are informed by both Herodotus[7] and +Diodorus[8], was made by a special officer, whose status, if we +may believe the explicit statement of Diodorus, was quite +comparable to that of the modern hangman. The paraschistas, as he +was called, having performed his necessary but obnoxious +function, with the aid of a sharp Ethiopian stone, retired +hastily, leaving the remaining processes to the priests. These, +however, confined their observations to the abdominal viscera; +under no consideration did they make other incisions in the body. +It follows, therefore, that their opportunity for anatomical +observations was most limited. + +Since even the necessary mutilation inflicted on the corpse was +regarded with such horror, it follows that anything in the way of +dissection for a less sacred purpose was absolutely prohibited. +Probably the same prohibition extended to a large number of +animals, since most of these were held sacred in one part of +Egypt or another. Moreover, there is nothing in what we know of +the Egyptian mind to suggest the probability that any Egyptian +physician would make extensive anatomical observations for the +love of pure knowledge. All Egyptian science is eminently +practical. If we think of the Egyptian as mysterious, it is +because of the superstitious observances that we everywhere +associate with his daily acts; but these, as we have already +tried to make clear, were really based on scientific observations +of a kind, and the attempt at true inferences from these +observations. But whether or not the Egyptian physician desired +anatomical knowledge, the results of his inquiries were certainly +most meagre. The essentials of his system had to do with a series +of vessels, alleged to be twenty-two or twenty-four in number, +which penetrated the head and were distributed in pairs to the +various members of the body, and which were vaguely thought of as +carriers of water, air, excretory fluids, etc. Yet back of this +vagueness, as must not be overlooked, there was an all-essential +recognition of the heart as the central vascular organ. The heart +is called the beginning of all the members. Its vessels, we are +told, "lead to all the members; whether the doctor lays his +finger on the forehead, on the back of the head, on the hands, on +the place of the stomach (?), on the arms, or on the feet, +everywhere he meets with the heart, because its vessels lead to +all the members."[9] This recognition of the pulse must be +credited to the Egyptian physician as a piece of practical +knowledge, in some measure off-setting the vagueness of his +anatomical theories. + + +ABSTRACT SCIENCE + +But, indeed, practical knowledge was, as has been said over and +over, the essential characteristic of Egyptian science. Yet +another illustration of this is furnished us if we turn to the +more abstract departments of thought and inquire what were the +Egyptian attempts in such a field as mathematics. The answer does +not tend greatly to increase our admiration for the Egyptian +mind. We are led to see, indeed, that the Egyptian merchant was +able to perform all the computations necessary to his craft, but +we are forced to conclude that the knowledge of numbers scarcely +extended beyond this, and that even here the methods of reckoning +were tedious and cumbersome. Our knowledge of the subject rests +largely upon the so- called papyrus Rhind,[10] which is a sort of +mythological hand-book of the ancient Egyptians. Analyzing this +document, Professor Erman concludes that the knowledge of the +Egyptians was adequate to all practical requirements. Their +mathematics taught them "how in the exchange of bread for beer +the respective value was to be determined when converted into a +quantity of corn; how to reckon the size of a field; how to +determine how a given quantity of corn would go into a granary of +a certain size," and like every-day problems. Yet they were +obliged to make some of their simple computations in a very +roundabout way. It would appear, for example, that their mental +arithmetic did not enable them to multiply by a number larger +than two, and that they did not reach a clear conception of +complex fractional numbers. They did, indeed, recognize that each +part of an object divided into 10 pieces became 1/10 of that +object; they even grasped the idea of 2/3 this being a conception +easily visualized; but they apparently did not visualize such a +conception as 3/10 except in the crude form of 1/10 plus 1/10 +plus 1/10. Their entire idea of division seems defective. They +viewed the subject from the more elementary stand-point of +multiplication. Thus, in order to find out how many times 7 is +contained in 77, an existing example shows that the numbers +representing 1 times 7, 2 times 7, 4 times 7, 8 times 7 were set +down successively and various experimental additions made to find +out which sets of these numbers aggregated 77. + + --1 7 + --2 14 + --4 28 + --8 56 + +A line before the first, second, and fourth of these numbers +indicated that it is necessary to multiply 7 by 1 plus 2 plus +8--that is, by 11, in order to obtain 77; that is to say, 7 goes +11 times in 77. All this seems very cumbersome indeed, yet we +must not overlook the fact that the process which goes on in our +own minds in performing such a problem as this is precisely +similar, except that we have learned to slur over certain of the +intermediate steps with the aid of a memorized multiplication +table. In the last analysis, division is only the obverse side of +multiplication, and any one who has not learned his +multiplication table is reduced to some such expedient as that of +the Egyptian. Indeed, whenever we pass beyond the range of our +memorized multiplication table-which for most of us ends with the +twelves--the experimental character of the trial multiplication +through which division is finally effected does not so greatly +differ from the experimental efforts which the Egyptian was +obliged to apply to smaller numbers. + +Despite his defective comprehension of fractions, the Egyptian +was able to work out problems of relative complexity; for +example, he could determine the answer of such a problem as this: +a number together with its fifth part makes 21; what is the +number? The process by which the Egyptian solved this problem +seems very cumbersome to any one for whom a rudimentary knowledge +of algebra makes it simple, yet the method which we employ +differs only in that we are enabled, thanks to our hypothetical +x, to make a short cut, and the essential fact must not be +overlooked that the Egyptian reached a correct solution of the +problem. With all due desire to give credit, however, the fact +remains that the Egyptian was but a crude mathematician. Here, as +elsewhere, it is impossible to admire him for any high +development of theoretical science. First, last, and all the +time, he was practical, and there is nothing to show that the +thought of science for its own sake, for the mere love of +knowing, ever entered his head. + +In general, then, we must admit that the Egyptian had not +progressed far in the hard way of abstract thinking. He +worshipped everything about him because he feared the result of +failing to do so. He embalmed the dead lest the spirit of the +neglected one might come to torment him. Eye-minded as he was, he +came to have an artistic sense, to love decorative effects. But +he let these always take precedence over his sense of truth; as, +for example, when he modified his lists of kings at Abydos to fit +the space which the architect had left to be filled; he had no +historical sense to show to him that truth should take precedence +over mere decoration. And everywhere he lived in the same +happy-go-lucky way. He loved personal ease, the pleasures of the +table, the luxuries of life, games, recreations, festivals. He +took no heed for the morrow, except as the morrow might minister +to his personal needs. Essentially a sensual being, he scarcely +conceived the meaning of the intellectual life in the modern +sense of the term. He had perforce learned some things about +astronomy, because these were necessary to his worship of the +gods; about practical medicine, because this ministered to his +material needs; about practical arithmetic, because this aided +him in every-day affairs. The bare rudiments of an historical +science may be said to be crudely outlined in his defective lists +of kings. But beyond this he did not go. Science as science, and +for its own sake, was unknown to him. He had gods for all +material functions, and festivals in honor of every god; but +there was no goddess of mere wisdom in his pantheon. The +conception of Minerva was reserved for the creative genius of +another people. + + +III. SCIENCE OF BABYLONIA AND ASSYRIA + +Throughout classical antiquity Egyptian science was famous. We +know that Plato spent some years in Egypt in the hope of +penetrating the alleged mysteries of its fabled learning; and the +story of the Egyptian priest who patronizingly assured Solon that +the Greeks were but babes was quoted everywhere without +disapproval. Even so late as the time of Augustus, we find +Diodorus, the Sicilian, looking back with veneration upon the +Oriental learning, to which Pliny also refers with unbounded +respect. From what we have seen of Egyptian science, all this +furnishes us with a somewhat striking commentary upon the +attainments of the Greeks and Romans themselves. To refer at +length to this would be to anticipate our purpose; what now +concerns us is to recall that all along there was another nation, +or group of nations, that disputed the palm for scientific +attainments. This group of nations found a home in the valley of +the Tigris and Euphrates. Their land was named Mesopotamia by the +Greeks, because a large part of it lay between the two rivers +just mentioned. The peoples themselves are familiar to every one +as the Babylonians and the Assyrians. These peoples were of +Semitic stock--allied, therefore, to the ancient Hebrews and +Phoenicians and of the same racial stem with the Arameans and +Arabs. + +The great capital of the Babylonians during the later period of +their history was the famed city of Babylon itself; the most +famous capital of the Assyrians was Nineveh, that city to which, +as every Bible- student will recall, the prophet Jonah was +journeying when he had a much-exploited experience, the record of +which forms no part of scientific annals. It was the kings of +Assyria, issuing from their palaces in Nineveh, who dominated the +civilization of Western Asia during the heyday of Hebrew history, +and whose deeds are so frequently mentioned in the Hebrew +chronicles. Later on, in the year 606 B.C., Nineveh was +overthrown by the Medes[1] and Babylonians. The famous city was +completely destroyed, never to be rebuilt. Babylon, however, +though conquered subsequently by Cyrus and held in subjection by +Darius,[2] the Persian kings, continued to hold sway as a great +world-capital for some centuries. The last great historical event +that occurred within its walls was the death of Alexander the +Great, which took place there in the year 322 B.C. + +In the time of Herodotus the fame of Babylon was at its height, +and the father of history has left us a most entertaining account +of what he saw when he visited the wonderful capital. +Unfortunately, Herodotus was not a scholar in the proper +acceptance of the term. He probably had no inkling of the +Babylonian language, so the voluminous records of its literature +were entirely shut off from his observation. He therefore +enlightens us but little regarding the science of the +Babylonians, though his observations on their practical +civilization give us incidental references of no small +importance. Somewhat more detailed references to the scientific +attainments of the Babylonians are found in the fragments that +have come down to us of the writings of the great Babylonian +historian, Berosus,[3] who was born in Babylon about 330 B.C., +and who was, therefore, a contemporary of Alexander the Great. +But the writings of Berosus also, or at least such parts of them +as have come down to us, leave very much to be desired in point +of explicitness. They give some glimpses of Babylonian history, +and they detail at some length the strange mythical tales of +creation that entered into the Babylonian conception of +cosmogony--details which find their counterpart in the allied +recitals of the Hebrews. But taken all in all, the glimpses of +the actual state of Chaldean[4] learning, as it was commonly +called, amounted to scarcely more than vague wonder-tales. No one +really knew just what interpretation to put upon these tales +until the explorers of the nineteenth century had excavated the +ruins of the Babylonian and Assyrian cities, bringing to light +the relics of their wonderful civilization. But these relics +fortunately included vast numbers of written documents, inscribed +on tablets, prisms, and cylinders of terra-cotta. When +nineteenth-century scholarship had penetrated the mysteries of +the strange script, and ferreted out the secrets of an unknown +tongue, the world at last was in possession of authentic records +by which the traditions regarding the Babylonians and Assyrians +could be tested. Thanks to these materials, a new science +commonly spoken of as Assyriology came into being, and a most +important chapter of human history was brought to light. It +became apparent that the Greek ideas concerning Mesopotamia, +though vague in the extreme, were founded on fact. No one any +longer questions that the Mesopotamian civilization was fully on +a par with that of Egypt; indeed, it is rather held that +superiority lay with the Asiatics. Certainly, in point of purely +scientific attainments, the Babylonians passed somewhat beyond +their Egyptian competitors. All the evidence seems to suggest +also that the Babylonian civilization was even more ancient than +that of Egypt. The precise dates are here in dispute; nor for our +present purpose need they greatly concern us. But the +Assyrio-Babylonian records have much greater historical accuracy +as regards matters of chronology than have the Egyptian, and it +is believed that our knowledge of the early Babylonian history is +carried back, with some certainty, to King Sargon of Agade,[5] +for whom the date 3800 B.C. is generally accepted; while somewhat +vaguer records give us glimpses of periods as remote as the +sixth, perhaps even the seventh or eighth millenniums before our +era. + +At a very early period Babylon itself was not a capital and +Nineveh had not come into existence. The important cities, such +as Nippur and Shirpurla, were situated farther to the south. It +is on the site of these cities that the recent excavations have +been made, such as those of the University of Pennsylvania +expeditions at Nippur,[6] which are giving us glimpses into +remoter recesses of the historical period. + +Even if we disregard the more problematical early dates, we are +still concerned with the records of a civilization extending +unbroken throughout a period of about four thousand years; the +actual period is in all probability twice or thrice that. +Naturally enough, the current of history is not an unbroken +stream throughout this long epoch. It appears that at least two +utterly different ethnic elements are involved. A preponderance +of evidence seems to show that the earliest civilized inhabitants +of Mesopotamia were not Semitic, but an alien race, which is now +commonly spoken of as Sumerian. This people, of whom we catch +glimpses chiefly through the records of its successors, appears +to have been subjugated or overthrown by Semitic invaders, who, +coming perhaps from Arabia (their origin is in dispute), took +possession of the region of the Tigris and Euphrates, learned +from the Sumerians many of the useful arts, and, partly perhaps +because of their mixed lineage, were enabled to develop the most +wonderful civilization of antiquity. Could we analyze the details +of this civilization from its earliest to its latest period we +should of course find the same changes which always attend racial +progress and decay. We should then be able, no doubt, to speak of +certain golden epochs and their periods of decline. To a certain +meagre extent we are able to do this now. We know, for example, +that King Khammurabi, who lived about 2200 B.C., was a great +law-giver, the ancient prototype of Justinian; and the epochs of +such Assyrian kings as Sargon II., Asshurnazirpal, Sennacherib, +and Asshurbanapal stand out with much distinctness. Yet, as a +whole, the record does not enable us to trace with clearness the +progress of scientific thought. At best we can gain fewer +glimpses in this direction than in almost any other, for it is +the record of war and conquest rather than of the peaceful arts +that commanded the attention of the ancient scribe. So in dealing +with the scientific achievements of these peoples, we shall +perforce consider their varied civilizations as a unity, and +attempt, as best we may, to summarize their achievements as a +whole. For the most part, we shall not attempt to discriminate as +to what share in the final product was due to Sumerian, what to +Babylonian, and what to Assyrian. We shall speak of Babylonian +science as including all these elements; and drawing our +information chiefly from the relatively late Assyrian and +Babylonian sources, which, therefore, represent the culminating +achievements of all these ages of effort, we shall attempt to +discover what was the actual status of Mesopotamian science at +its climax. In so far as we succeed, we shall be able to judge +what scientific heritage Europe received from the Orient; for in +the records of Babylonian science we have to do with the Eastern +mind at its best. Let us turn to the specific inquiry as to the +achievements of the Chaldean scientist whose fame so dazzled the +eyes of his contemporaries of the classic world. + + +BABYLONIAN ASTRONOMY + +Our first concern naturally is astronomy, this being here, as in +Egypt, the first-born and the most important of the sciences. The +fame of the Chaldean astronomer was indeed what chiefly commanded +the admiration of the Greeks, and it was through the results of +astronomical observations that Babylonia transmitted her most +important influences to the Western world. "Our division of time +is of Babylonian origin," says Hornmel;[7] "to Babylonia we owe +the week of seven days, with the names of the planets for the +days of the week, and the division into hours and months." Hence +the almost personal interest which we of to-day must needs feel +in the efforts of the Babylonian star-gazer. + +It must not be supposed, however, that the Chaldean astronomer +had made any very extraordinary advances upon the knowledge of +the Egyptian "watchers of the night." After all, it required +patient observation rather than any peculiar genius in the +observer to note in the course of time such broad astronomical +conditions as the regularity of the moon's phases, and the +relation of the lunar periods to the longer periodical +oscillations of the sun. Nor could the curious wanderings of the +planets escape the attention of even a moderately keen observer. +The chief distinction between the Chaldean and Egyptian +astronomers appears to have consisted in the relative importance +they attached to various of the phenomena which they both +observed. The Egyptian, as we have seen, centred his attention +upon the sun. That luminary was the abode of one of his most +important gods. His worship was essentially solar. The +Babylonian, on the other hand, appears to have been peculiarly +impressed with the importance of the moon. He could not, of +course, overlook the attention-compelling fact of the solar year; +but his unit of time was the lunar period of thirty days, and his +year consisted of twelve lunar periods, or 360 days. He was +perfectly aware, however, that this period did not coincide with +the actual year; but the relative unimportance which he ascribed +to the solar year is evidenced by the fact that he interpolated +an added month to adjust the calendar only once in six years. +Indeed, it would appear that the Babylonians and Assyrians did +not adopt precisely the same method of adjusting the calendar, +since the Babylonians had two intercular months called Elul and +Adar, whereas the Assyrians had only a single such month, called +the second Adar.[8] (The Ve'Adar of the Hebrews.) This diversity +further emphasizes the fact that it was the lunar period which +received chief attention, the adjustment of this period with the +solar seasons being a necessary expedient of secondary +importance. It is held that these lunar periods have often been +made to do service for years in the Babylonian computations and +in the allied computations of the early Hebrews. The lives of the +Hebrew patriarchs, for example, as recorded in the Bible, are +perhaps reckoned in lunar "years." Divided by twelve, the "years" +of Methuselah accord fairly with the usual experience of mankind. + +Yet, on the other hand, the convenience of the solar year in +computing long periods of time was not unrecognized, since this +period is utilized in reckoning the reigns of the Assyrian kings. +It may be added that the reign of a king "was not reckoned from +the day of his accession, but from the Assyrian new year's day, +either before or after the day of accession. There does not +appear to have been any fixed rule as to which new year's day +should be chosen; but from the number of known cases, it appears +to have been the general practice to count the reigning years +from the new year's day nearest the accession, and to call the +period between the accession day and the first new year's day +'the beginning of the reign,' when the year from the new year's +day was called the first year, and the following ones were +brought successively from it. Notwithstanding, in the dates of +several Assyrian and Babylonian sovereigns there are cases of the +year of accession being considered as the first year, thus giving +two reckonings for the reigns of various monarchs, among others, +Shalmaneser, Sennacherib, Nebuchadrezzar."[9] This uncertainty as +to the years of reckoning again emphasizes the fact that the +solar year did not have for the Assyrian chronology quite the +same significance that it has for us. + +The Assyrian month commenced on the evening when the new moon was +first observed, or, in case the moon was not visible, the new +month started thirty days after the last month. Since the actual +lunar period is about twenty-nine and one-half days, a practical +adjustment was required between the months themselves, and this +was probably effected by counting alternate months as Only 29 +days in length. Mr. R. Campbell Thompson[10] is led by his +studies of the astrological tablets to emphasize this fact. He +believes that "the object of the astrological reports which +related to the appearance of the moon and sun was to help +determine and foretell the length of the lunar month." Mr. +Thompson believes also that there is evidence to show that the +interculary month was added at a period less than six years. In +point of fact, it does not appear to be quite clearly established +as to precisely how the adjustment of days with the lunar months, +and lunar months with the solar year, was effected. It is clear, +however, according to Smith, "that the first 28 days of every +month were divided into four weeks of seven days each; the +seventh, fourteenth, twenty-first, twenty-eighth days +respectively being Sabbaths, and that there was a general +prohibition of work on these days." Here, of course, is the +foundation of the Hebrew system of Sabbatical days which we have +inherited. The sacredness of the number seven itself--the belief +in which has not been quite shaken off even to this day --was +deduced by the Assyrian astronomer from his observation of the +seven planetary bodies--namely, Sin (the moon), Samas (the sun), +Umunpawddu (Jupiter), Dilbat (Venus), Kaimanu (Saturn), Gudud +(Mercury), Mustabarru-mutanu (Mars).[11] Twelve lunar periods, +making up approximately the solar year, gave peculiar importance +to the number twelve also. Thus the zodiac was divided into +twelve signs which astronomers of all subsequent times have +continued to recognize; and the duodecimal system of counting +took precedence with the Babylonian mathematicians over the more +primitive and, as it seems to us, more satisfactory decimal +system. + +Another discrepancy between the Babylonian and Egyptian years +appears in the fact that the Babylonian new year dates from about +the period of the vernal equinox and not from the solstice. +Lockyer associates this with the fact that the periodical +inundation of the Tigris and Euphrates occurs about the +equinoctial period, whereas, as we have seen, the Nile flood +comes at the time of the solstice. It is but natural that so +important a phenomenon as the Nile flood should make a strong +impression upon the minds of a people living in a valley. The +fact that occasional excessive inundations have led to most +disastrous results is evidenced in the incorporation of stories +of the almost total destruction of mankind by such floods among +the myth tales of all peoples who reside in valley countries. The +flooding of the Tigris and Euphrates had not, it is true, quite +the same significance for the Mesopotamians that the Nile flood +had for the Egyptians. Nevertheless it was a most important +phenomenon, and may very readily be imagined to have been the +most tangible index to the seasons. But in recognizing the time +of the inundations and the vernal equinox, the Assyrians did not +dethrone the moon from its accustomed precedence, for the year +was reckoned as commencing not precisely at the vernal equinox, +but at the new moon next before the equinox. + + +ASTROLOGY + +Beyond marking the seasons, the chief interests that actuated the +Babylonian astronomer in his observations were astrological. +After quoting Diodorus to the effect that the Babylonian priests +observed the position of certain stars in order to cast +horoscopes, Thompson tells us that from a very early day the very +name Chaldean became synonymous with magician. He adds that "from +Mesopotamia, by way of Greece and Rome, a certain amount of +Babylonian astrology made its way among the nations of the west, +and it is quite probable that many superstitions which we +commonly record as the peculiar product of western civilization +took their origin from those of the early dwellers on the +alluvial lands of Mesopotamia. One Assurbanipal, king of Assyria +B.C. 668-626, added to the royal library at Nineveh his +contribution of tablets, which included many series of documents +which related exclusively to the astrology of the ancient +Babylonians, who in turn had borrowed it with modifications from +the Sumerian invaders of the country. Among these must be +mentioned the series which was commonly called 'the Day of Bel,' +and which was decreed by the learned to have been written in the +time of the great Sargon I., king of Agade, 3800 B.C. With such +ancient works as these to guide them, the profession of deducing +omens from daily events reached such a pitch of importance in the +last Assyrian Empire that a system of making periodical reports +came into being. By these the king was informed of all the +occurrences in the heavens and on earth, and the results of +astrological studies in respect to after events. The heads of the +astrological profession were men of high rank and position, and +their office was hereditary. The variety of information contained +in these reports is best gathered from the fact that they were +sent from cities as far removed from each other as Assur in the +north and Erech in the south, and it can only be assumed that +they were despatched by runners, or men mounted on swift horses. +As reports also came from Dilbat, Kutba, Nippur, and Bursippa, +all cities of ancient foundation, the king was probably well +acquainted with the general course of events in his empire."[12] + +From certain passages in the astrological tablets, Thompson draws +the interesting conclusion that the Chaldean astronomers were +acquainted with some kind of a machine for reckoning time. He +finds in one of the tablets a phrase which he interprets to mean +measure-governor, and he infers from this the existence of a kind +of a calculator. He calls attention also to the fact that Sextus +Empiricus[13] states that the clepsydra was known to the +Chaldeans, and that Herodotus asserts that the Greeks borrowed +certain measures of time from the Babylonians. He finds further +corroboration in the fact that the Babylonians had a time-measure +by which they divided the day and the night; a measure called +kasbu, which contained two hours. In a report relating to the day +of the vernal equinox, it is stated that there are six kasbu of +the day and six kasbu of the night. + +While the astrologers deduced their omens from all the celestial +bodies known to them, they chiefly gave attention to the moon, +noting with great care the shape of its horns, and deducing such +a conclusion as that "if the horns are pointed the king will +overcome whatever he goreth," and that "when the moon is low at +its appearance, the submission (of the people) of a far country +will come."[14] The relations of the moon and sun were a source +of constant observation, it being noted whether the sun and moon +were seen together above the horizon; whether one set as the +other rose, and the like. And whatever the phenomena, there was +always, of course, a direct association between such phenomena +and the well-being of human kind--in particular the king, at +whose instance, and doubtless at whose expense, the observations +were carried out. + +From omens associated with the heavenly bodies it is but a step +to omens based upon other phenomena of nature, and we, shall see +in a moment that the Babylonian prophets made free use of their +opportunities in this direction also. But before we turn from the +field of astronomy, it will be well to inform ourselves as to +what system the Chaldean astronomer had invented in explanation +of the mechanics of the universe. Our answer to this inquiry is +not quite as definite as could be desired, the vagueness of the +records, no doubt, coinciding with the like vagueness in the +minds of the Chaldeans themselves. So far as we can interpret the +somewhat mystical references that have come down to us, however, +the Babylonian cosmology would seem to have represented the earth +as a circular plane surrounded by a great circular river, beyond +which rose an impregnable barrier of mountains, and resting upon +an infinite sea of waters. The material vault of the heavens was +supposed to find support upon the outlying circle of mountains. +But the precise mechanism through which the observed revolution +of the heavenly bodies was effected remains here, as with the +Egyptian cosmology, somewhat conjectural. The simple fact would +appear to be that, for the Chaldeans as for the Egyptians, +despite their most careful observations of the tangible phenomena +of the heavens, no really satisfactory mechanical conception of +the cosmos was attainable. We shall see in due course by what +faltering steps the European imagination advanced from the crude +ideas of Egypt and Babylonia to the relatively clear vision of +Newton and Laplace. + + +CHALDEAN MAGIC + +We turn now from the field of the astrologer to the closely +allied province of Chaldean magic--a province which includes the +other; which, indeed, is so all- encompassing as scarcely to +leave any phase of Babylonian thought outside its bounds. + +The tablets having to do with omens, exorcisms, and the like +magic practices make up an astonishingly large proportion of the +Babylonian records. In viewing them it is hard to avoid the +conclusion that the superstitions which they evidenced absolutely +dominated the life of the Babylonians of every degree. Yet it +must not be forgotten that the greatest inconsistencies +everywhere exist between the superstitious beliefs of a people +and the practical observances of that people. No other problem is +so difficult for the historian as that which confronts him when +he endeavors to penetrate the mysteries of an alien religion; and +when, as in the present case, the superstitions involved have +been transmitted from generation to generation, their exact +practical phases as interpreted by any particular generation must +be somewhat problematical. The tablets upon which our knowledge +of these omens is based are many of them from the libraries of +the later kings of Nineveh; but the omens themselves are, in such +cases, inscribed in the original Accadian form in which they have +come down from remote ages, accompanied by an Assyrian +translation. Thus the superstitions involved had back of them +hundreds of years, even thousands of years, of precedent; and we +need not doubt that the ideas with which they are associated were +interwoven with almost every thought and deed of the life of the +people. Professor Sayce assures us that the Assyrians and +Babylonians counted no fewer than three hundred spirits of +heaven, and six hundred spirits of earth. "Like the Jews of the +Talmud," he says, "they believed that the world was swarming with +noxious spirits, who produced the various diseases to which man +is liable, and might be swallowed with the food and drink which +support life." Fox Talbot was inclined to believe that exorcisms +were the exclusive means used to drive away the tormenting +spirits. This seems unlikely, considering the uniform association +of drugs with the magical practices among their people. Yet there +is certainly a strange silence of the tablets in regard to +medicine. Talbot tells us that sometimes divine images were +brought into the sick-chamber, and written texts taken from holy +books were placed on the walls and bound around the sick man's +members. If these failed, recourse was had to the influence of +the mamit, which the evil powers were unable to resist. On a +tablet, written in the Accadian language only, the Assyrian +version being taken, however, was found the following: + + 1. Take a white cloth. In it place the mamit, + 2. in the sick man's right hand. + 3. Take a black cloth, + 4. wrap it around his left hand. + 5. Then all the evil spirits (a long list of them is given) + 6. and the sins which he has committed + 7. shall quit their hold of him + 8. and shall never return. + + +The symbolism of the black cloth in the left hand seems evident. +The dying man repents of his former evil deeds, and he puts his +trust in holiness, symbolized by the white cloth in his right +hand. Then follow some obscure lines about the spirits: + + 1. Their heads shall remove from his head. + 2. Their heads shall let go his hands. + 3. Their feet shall depart from his feet. + +Which perhaps may be explained thus: we learn from another tablet +that the various classes of evil spirits troubled different parts +of the body; some injured the head, some the hands and the feet, +etc., therefore the passage before may mean "the spirits whose +power is over the hand shall loose their hands from his," etc. +"But," concludes Talbot, "I can offer no decided opinion upon +such obscure points of their superstition."[15] + +In regard to evil spirits, as elsewhere, the number seven had a +peculiar significance, it being held that that number of spirits +might enter into a man together. Talbot has translated[16] a +"wild chant" which he names "The Song of the Seven Spirits." + + 1. There are seven! There are seven! + 2. In the depths of the ocean there are seven! + 3. In the heights of the heaven there are seven! + 4. In the ocean stream in a palace they were born. + 5. Male they are not: female they are not! + 6. Wives they have not! Children are not born to them! + 7. Rules they have not! Government they know not! + 8. Prayers they hear not! + 9. There are seven! There are seven! Twice over there are +seven! + +The tablets make frequent allusion to these seven spirits. One +starts thus: + + 1. The god (---) shall stand by his bedside; + 2. These seven evil spirits he shall root out and shall expel +them from his body, + 3. and these seven shall never return to the sick man +again.[17] + + +Altogether similar are the exorcisms intended to ward off +disease. Professor Sayce has published translations of some of +these.[18] Each of these ends with the same phrase, and they +differ only in regard to the particular maladies from which +freedom is desired. One reads: + +"From wasting, from want of health, from the evil spirit of the +ulcer, from the spreading quinsy of the gullet, from the violent +ulcer, from the noxious ulcer, may the king of heaven preserve, +may the king of earth preserve." + +Another is phrased thus: + +"From the cruel spirit of the head, from the strong spirit of the +head, from the head spirit that departs not, from the head spirit +that comes not forth, from the head spirit that will not go, from +the noxious head spirit, may the king of heaven preserve, may the +king of earth preserve." + +As to omens having to do with the affairs of everyday life the +number is legion. For example, Moppert has published, in the +Journal Asiatique,[19] the translation of a tablet which contains +on its two sides several scores of birth-portents, a few of which +maybe quoted at random: + +"When a woman bears a child and it has the ears of a lion, a +strong king is in the country." "When a woman bears a child and +it has a bird's beak, that country is oppressed." "When a woman +bears a child and its right hand is wanting, that country goes to +destruction." "When a woman bears a child and its feet are +wanting, the roads of the country are cut; that house is +destroyed." "When a woman bears a child and at the time of its +birth its beard is grown, floods are in the country." "When a +woman bears a child and at the time of its birth its mouth is +open and speaks, there is pestilence in the country, the Air-god +inundates the crops of the country, injury in the country is +caused." + +Some of these portents, it will be observed, are not in much +danger of realization, and it is curious to surmise by what +stretch of the imagination they can have been invented. There is, +for example, on the same tablet just quoted, one reference which +assures us that "when a sheep bears a lion the forces march +multitudinously; the king has not a rival." There are other +omens, however, that are so easy of realization as to lead one to +suppose that any Babylonian who regarded all the superstitious +signs must have been in constant terror. Thus a tablet translated +by Professor Sayce[20] gives a long list of omens furnished by +dogs, in which we are assured that: + + 1. If a yellow dog enters into the palace, exit from that +palace will be baleful. + 2. If a dog to the palace goes, and on a throne lies down, that +palace is burned. + 3. if a black dog into a temple enters, the foundation of that +temple is not stable. + 4. If female dogs one litter bear, destruction to the city. + +It is needless to continue these citations, since they but +reiterate endlessly the same story. It is interesting to recall, +however, that the observations of animate nature, which were +doubtless superstitious in their motive, had given the +Babylonians some inklings of a knowledge of classification. Thus, +according to Menant,[21] some of the tablets from Nineveh, which +are written, as usual, in both the Sumerian and Assyrian +languages, and which, therefore, like practically all Assyrian +books, draw upon the knowledge of old Babylonia, give lists of +animals, making an attempt at classification. The dog, lion, and +wolf are placed in one category; the ox, sheep, and goat in +another; the dog family itself is divided into various races, as +the domestic dog, the coursing dog, the small dog, the dog of +Elan, etc. Similar attempts at classification of birds are found. +Thus, birds of rapid flight, sea-birds, and marsh-birds are +differentiated. Insects are classified according to habit; those +that attack plants, animals, clothing, or wood. Vegetables seem +to be classified according to their usefulness. One tablet +enumerates the uses of wood according to its adaptability for +timber-work of palaces, or construction of vessels, the making of +implements of husbandry, or even furniture. Minerals occupy a +long series in these tablets. They are classed according to their +qualities, gold and silver occupying a division apart; precious +stones forming another series. Our Babylonians, then, must be +credited with the development of a rudimentary science of natural +history. + + +BABYLONIAN MEDICINE + +We have just seen that medical practice in the Babylonian world +was strangely under the cloud of superstition. But it should be +understood that our estimate, through lack of correct data, +probably does much less than justice to the attainments of the +physician of the time. As already noted, the existing tablets +chance not to throw much light on the subject. It is known, +however, that the practitioner of medicine occupied a position of +some, authority and responsibility. The proof of this is found in +the clauses relating to the legal status of the physician which +are contained in the now famous code[22] of the Babylonian King +Khamurabi, who reigned about 2300 years before our era. These +clauses, though throwing no light on the scientific attainments +of the physician of the period, are too curious to be omitted. +They are clauses 215 to 227 of the celebrated code, and are as +follows: + +215. If a doctor has treated a man for a severe wound with a +lancet of bronze and has cured the man, or has opened a tumor +with a bronze lancet and has cured the man's eye, he shall +receive ten shekels of silver. + +216. If it was a freedman, he shall receive five shekels of +silver. + +217. If it was a man's slave, the owner of the slave shall give +the doctor two shekels of silver. + +218. If a physician has treated a free-born man for a severe +wound with a lancet of bronze and has caused the man to die, or +has opened a tumor of the man with a lancet of bronze and has +destroyed his eye, his hands one shall cut off. + +219. If the doctor has treated the slave of a freedman for a +severe wound with a bronze lancet and has caused him to die, he +shall give back slave for slave. + +220. If he has opened his tumor with a bronze lancet and has +ruined his eye, he shall pay the half of his price in money. + +221. If a doctor has cured the broken limb of a man, or has +healed his sick body, the patient shall pay the doctor five +shekels of silver. + +222. If it was a freedman, he shall give three shekels of silver. + +223. If it was a man's slave, the owner of the slave shall give +two shekels of silver to the doctor. + +224. If the doctor of oxen and asses has treated an ox or an ass +for a grave wound and has cured it, the owner of the ox or the +ass shall give to the doctor as his pay one-sixth of a shekel of +silver. + +225. If he has treated an ox or an ass for a severe wound and has +caused its death, he shall pay one-fourth of its price to the +owner of the ox or the ass. + +226. If a barber-surgeon, without consent of the owner of a +slave, has branded the slave with an indelible mark, one shall +cut off the hands of that barber. + +227. If any one deceive the surgeon-barber and make him brand a +slave with an indelible mark, one shall kill that man and bury +him in his house. The barber shall swear, "I did not mark him +wittingly," and he shall be guiltless. + + +ESTIMATES OF BABYLONIAN SCIENCE + +Before turning from the Oriental world it is perhaps worth while +to attempt to estimate somewhat specifically the world-influence +of the name, Babylonian science. Perhaps we cannot better gain an +idea as to the estimate put upon that science by the classical +world than through a somewhat extended quotation from a classical +author. Diodorus Siculus, who, as already noted, lived at about +the time of Augustus, and who, therefore, scanned in perspective +the entire sweep of classical Greek history, has left us a +striking summary which is doubly valuable because of its +comparisons of Babylonian with Greek influence. Having viewed the +science of Babylonia in the light of the interpretations made +possible by the recent study of original documents, we are +prepared to draw our own conclusions from the statements of the +Greek historian. Here is his estimate in the words of the quaint +translation made by Philemon Holland in the year 1700:[23] + + +"They being the most ancient Babylonians, hold the same station +and dignity in the Common-wealth as the Egyptian Priests do in +Egypt: For being deputed to Divine Offices, they spend all their +Time in the study of Philosophy, and are especially famous for +the Art of Astrology. They are mightily given to Divination, and +foretel future Events, and imploy themselves either by +Purifications, Sacrifices, or other Inchantments to avert Evils, +or procure good Fortune and Success. They are skilful likewise in +the Art of Divination, by the flying of Birds, and interpreting +of Dreams and Prodigies: And are reputed as true Oracles (in +declaring what will come to pass) by their exact and diligent +viewing the Intrals of the Sacrifices. But they attain not to +this Knowledge in the same manner as the Grecians do; for the +Chaldeans learn it by Tradition from their Ancestors, the Son +from the Father, who are all in the mean time free from all other +publick Offices and Attendances; and because their Parents are +their Tutors, they both learn every thing without Envy, and rely +with more confidence upon the truth of what is taught them; and +being train'd up in this Learning, from their very Childhood, +they become most famous Philosophers, (that Age being most +capable of Learning, wherein they spend much of their time). But +the Grecians for the most part come raw to this study, unfitted +and unprepar'd, and are long before they attain to the Knowledge +of this Philosophy: And after they have spent some small time in +this Study, they are many times call'd off and forc'd to leave +it, in order to get a Livelihood and Subsistence. And although +some, few do industriously apply themselves to Philosophy, yet +for the sake of Gain, these very Men are opinionative, and ever +and anon starting new and high Points, and never fix in the steps +of their Ancestors. But the Barbarians keeping constantly close +to the same thing, attain to a perfect and distinct Knowledge in +every particular. + +"But the Grecians, cunningly catching at all Opportunities of +Gain, make new Sects and Parties, and by their contrary Opinions +wrangling and quarelling concerning the chiefest Points, lead +their Scholars into a Maze; and being uncertain and doubtful what +to pitch upon for certain truth, their Minds are fluctuating and +in suspence all the days of their Lives, and unable to give a +certain assent unto any thing. For if any Man will but examine +the most eminent Sects of the Philosophers, he shall find them +much differing among themselves, and even opposing one another in +the most weighty parts of their Philosophy. But to return to the +Chaldeans, they hold that the World is eternal, which had neither +any certain Beginning, nor shall have any End; but all agree, +that all things are order'd, and this beautiful Fabrick is +supported by a Divine Providence, and that the Motions of the +Heavens are not perform'd by chance and of their own accord, but +by a certain and determinate Will and Appointment of the Gods. + +"Therefore from a long observation of the Stars, and an exact +Knowledge of the motions and influences of every one of them, +wherein they excel all others, they fortel many things that are +to come to pass. + +"They say that the Five Stars which some call Planets, but they +Interpreters, are most worthy of Consideration, both for their +motions and their remarkable influences, especially that which +the Grecians call Saturn. The brightest of them all, and which +often portends many and great Events, they call Sol, the other +Four they name Mars, Venus, Mercury, and Jupiter, with our own +Country Astrologers. They give the Name of Interpreters to these +Stars, because these only by a peculiar Motion do portend things +to come, and instead of Jupiters, do declare to Men before-hand +the good- will of the Gods; whereas the other Stars (not being of +the number of the Planets) have a constant ordinary motion. +Future Events (they say) are pointed at sometimes by their +Rising, and sometimes by their Setting, and at other times by +their Colour, as may be experienc'd by those that will diligently +observe it; sometimes foreshewing Hurricanes, at other times +Tempestuous Rains, and then again exceeding Droughts. By these, +they say, are often portended the appearance of Comets, Eclipses +of the Sun and Moon, Earthquakes and all other the various +Changes and remarkable effects in the Air, boding good and bad, +not only to Nations in general, but to Kings and Private Persons +in particular. Under the course of these Planets, they say are +Thirty Stars, which they call Counselling Gods, half of whom +observe what is done under the Earth, and the other half take +notice of the actions of Men upon the Earth, and what is +transacted in the Heavens. Once every Ten Days space (they say) +one of the highest Order of these Stars descends to them that are +of the lowest, like a Messenger sent from them above; and then +again another ascends from those below to them above, and that +this is their constant natural motion to continue for ever. The +chief of these Gods, they say, are Twelve in number, to each of +which they attribute a Month, and one Sign of the Twelve in the +Zodiack. + +"Through these Twelve Signs the Sun, Moon, and the other Five +Planets run their Course. The Sun in a Years time, and the Moon +in the space of a Month. To every one of the Planets they assign +their own proper Courses, which are perform'd variously in lesser +or shorter time according as their several motions are quicker or +slower. These Stars, they say, have a great influence both as to +good and bad in Mens Nativities; and from the consideration of +their several Natures, may be foreknown what will befal Men +afterwards. As they foretold things to come to other Kings +formerly, so they did to Alexander who conquer'd Darius, and to +his Successors Antigonus and Seleucus Nicator; and accordingly +things fell out as they declar'd; which we shall relate +particularly hereafter in a more convenient time. They tell +likewise private Men their Fortunes so certainly, that those who +have found the thing true by Experience, have esteem'd it a +Miracle, and above the reach of man to perform. Out of the Circle +of the Zodiack they describe Four and Twenty Stars, Twelve +towards the North Pole, and as many to the South. + +"Those which we see, they assign to the living; and the other +that do not appear, they conceive are Constellations for the +Dead; and they term them Judges of all things. The Moon, they +say, is in the lowest Orb; and being therefore next to the Earth +(because she is so small), she finishes her Course in a little +time, not through the swiftness of her Motion, but the shortness +of her Sphear. In that which they affirm (that she has but a +borrow'd light, and that when she is eclips'd, it's caus'd by the +interposition of the shadow of the Earth) they agree with the +Grecians. + +"Their Rules and Notions concerning the Eclipses of the Sun are +but weak and mean, which they dare not positively foretel, nor +fix a certain time for them. They have likewise Opinions +concerning the Earth peculiar to themselves, affirming it to +resemble a Boat, and to be hollow, to prove which, and other +things relating to the frame of the World, they abound in +Arguments; but to give a particular Account of 'em, we conceive +would be a thing foreign to our History. But this any Man may +justly and truly say, That the Chaldeans far exceed all other Men +in the Knowledge of Astrology, and have study'd it most of any +other Art or Science: But the number of years during which the +Chaldeans say, those of their Profession have given themselves to +the study of this natural Philosophy, is incredible; for when +Alexander was in Asia, they reckon'd up Four Hundred and Seventy +Thousand Years since they first began to observe the Motions of +the Stars." + + +Let us now supplement this estimate of Babylonian influence with +another estimate written in our own day, and quoted by one of the +most recent historians of Babylonia and Assyria.[24] The estimate +in question is that of Canon Rawlinson in his Great Oriental +Monarchies.[25] Of Babylonia he says: + +"Hers was apparently the genius which excogitated an alphabet; +worked out the simpler problems of arithmetic; invented +implements for measuring the lapse of time; conceived the idea of +raising enormous structures with the poorest of all materials, +clay; discovered the art of polishing, boring, and engraving +gems; reproduced with truthfulness the outlines of human and +animal forms; attained to high perfection in textile fabrics; +studied with success the motions of the heavenly bodies; +conceived of grammar as a science; elaborated a system of law; +saw the value of an exact chronology--in almost every branch of +science made a beginning, thus rendering it comparatively easy +for other nations to proceed with the superstructure.... It was +from the East, not from Egypt, that Greece derived her +architecture, her sculpture, her science, her philosophy, her +mathematical knowledge--in a word, her intellectual life. And +Babylon was the source to which the entire stream of Eastern +civilization may be traced. It is scarcely too much to say that, +but for Babylon, real civilization might not yet have dawned upon +the earth." + + +Considering that a period of almost two thousand years separates +the times of writing of these two estimates, the estimates +themselves are singularly in unison. They show that the greatest +of Oriental nations has not suffered in reputation at the hands +of posterity. It is indeed almost impossible to contemplate the +monuments of Babylonian and Assyrian civilization that are now +preserved in the European and American museums without becoming +enthusiastic. That certainly was a wonderful civilization which +has left us the tablets on which are inscribed the laws of a +Khamurabi on the one hand, and the art treasures of the palace of +an Asshurbanipal on the other. Yet a candid consideration of the +scientific attainments of the Babylonians and Assyrians can +scarcely arouse us to a like enthusiasm. In considering the +subject we have seen that, so far as pure science is concerned, +the efforts of the Babylonians and Assyrians chiefly centred +about the subjects of astrology and magic. With the records of +their ghost-haunted science fresh in mind, one might be forgiven +for a momentary desire to take issue with Canon Rawlinson's +words. We are assured that the scientific attainments of Europe +are almost solely to be credited to Babylonia and not to Egypt, +but we should not forget that Plato, the greatest of the Greek +thinkers, went to Egypt and not to Babylonia to pursue his +studies when he wished to penetrate the secrets of Oriental +science and philosophy. Clearly, then, classical Greece did not +consider Babylonia as having a monopoly of scientific knowledge, +and we of to-day, when we attempt to weigh the new evidence that +has come to us in recent generations with the Babylonian records +themselves, find that some, at least, of the heritages for which +Babylonia has been praised are of more than doubtful value. +Babylonia, for example, gave us our seven-day week and our system +of computing by twelves. But surely the world could have got on +as well without that magic number seven; and after some hundreds +of generations we are coming to feel that the decimal system of +the Egyptians has advantages over the duodecimal system of the +Babylonians. Again, the Babylonians did not invent the alphabet; +they did not even accept it when all the rest of the world had +recognized its value. In grammar and arithmetic, as with +astronomy, they seemed not to have advanced greatly, if at all, +upon the Egyptians. One field in which they stand out in +startling pre- eminence is the field of astrology; but this, in +the estimate of modern thought, is the very negation of science. +Babylonia impressed her superstitions on the Western world, and +when we consider the baleful influence of these superstitions, we +may almost question whether we might not reverse Canon +Rawlinson's estimate and say that perhaps but for Babylonia real +civilization, based on the application of true science, might +have dawned upon the earth a score of centuries before it did. +Yet, after all, perhaps this estimate is unjust. Society, like an +individual organism, must creep before it can walk, and perhaps +the Babylonian experiments in astrology and magic, which European +civilization was destined to copy for some three or four thousand +years, must have been made a part of the necessary evolution of +our race in one place or in another. That thought, however, need +not blind us to the essential fact, which the historian of +science must needs admit, that for the Babylonian, despite his +boasted culture, science spelled superstition. + + + +IV. THE DEVELOPMENT OF THE ALPHABET + +Before we turn specifically to the new world of the west, it +remains to take note of what may perhaps be regarded as the very +greatest achievement of ancient science. This was the analysis of +speech sounds, and the resulting development of a system of +alphabetical writing. To comprehend the series of scientific +inductions which led to this result, we must go back in +imagination and trace briefly the development of the methods of +recording thought by means of graphic symbols. In other words, we +must trace the evolution of the art of writing. In doing so we +cannot hold to national lines as we have done in the preceding +two chapters, though the efforts of the two great scientific +nations just considered will enter prominently into the story. + +The familiar Greek legend assures us that a Phoenician named +Kadmus was the first to bring a knowledge of letters into Europe. +An elaboration of the story, current throughout classical times, +offered the further explanation that the Phoenicians had in turn +acquired the art of writing from the Egyptians or Babylonians. +Knowledge as to the true origin and development of the art of +writing did not extend in antiquity beyond such vagaries as +these. Nineteenth-century studies gave the first real clews to an +understanding of the subject. These studies tended to +authenticate the essential fact on which the legend of Kadmus was +founded; to the extent, at least, of making it probable that the +later Grecian alphabet was introduced from Phoenicia--though not, +of course, by any individual named Kadmus, the latter being, +indeed, a name of purely Greek origin. Further studies of the +past generation tended to corroborate the ancient belief as to +the original source of the Phoenician alphabet, but divided +scholars between two opinions: the one contending that the +Egyptian hieroglyphics were the source upon which the Phoenicians +drew; and the other contending with equal fervor that the +Babylonian wedge character must be conceded that honor. + +But, as has often happened in other fields after years of +acrimonious controversy, a new discovery or two may suffice to +show that neither contestant was right. After the Egyptologists +of the school of De Rouge[1] thought they had demonstrated that +the familiar symbols of the Phoenician alphabet had been copied +from that modified form of Egyptian hieroglyphics known as the +hieratic writing, the Assyriologists came forward to prove that +certain characters of the Babylonian syllabary also show a +likeness to the alphabetical characters that seemingly could not +be due to chance. And then, when a settlement of the dispute +seemed almost hopeless, it was shown through the Egyptian +excavations that characters even more closely resembling those in +dispute had been in use all about the shores of the +Mediterranean, quite independently of either Egyptian or Assyrian +writings, from periods so ancient as to be virtually prehistoric. + +Coupled with this disconcerting discovery are the revelations +brought to light by the excavations at the sites of Knossos and +other long-buried cities of the island of Crete.[2] These +excavations, which are still in progress, show that the art of +writing was known and practised independently in Crete before +that cataclysmic overthrow of the early Greek civilization which +archaeologists are accustomed to ascribe to the hypothetical +invasion of the Dorians. The significance of this is that the art +of writing was known in Europe long before the advent of the +mythical Kadmus. But since the early Cretan scripts are not to be +identified with the scripts used in Greece in historical times, +whereas the latter are undoubtedly of lineal descent from the +Phoenician alphabet, the validity of the Kadmus legend, in a +modified form, must still be admitted. + +As has just been suggested, the new knowledge, particularly that +which related to the great antiquity of characters similar to the +Phoenician alphabetical signs, is somewhat disconcerting. Its +general trend, however, is quite in the same direction with most +of the new archaeological knowledge of recent decades---that is +to say, it tends to emphasize the idea that human civilization in +most of its important elaborations is vastly older than has +hitherto been supposed. It may be added, however, that no +definite clews are as yet available that enable us to fix even an +approximate date for the origin of the Phoenician alphabet. The +signs, to which reference has been made, may well have been in +existence for thousands of years, utilized merely as property +marks, symbols for counting and the like, before the idea of +setting them aside as phonetic symbols was ever conceived. +Nothing is more certain, in the judgment of the present-day +investigator, than that man learned to write by slow and painful +stages. It is probable that the conception of such an analysis of +speech sounds as would make the idea of an alphabet possible came +at a very late stage of social evolution, and as the culminating +achievement of a long series of improvements in the art of +writing. The precise steps that marked this path of intellectual +development can for the most part be known only by inference; yet +it is probable that the main chapters of the story may be +reproduced with essential accuracy. + + +FIRST STEPS + +For the very first chapters of the story we must go back in +imagination to the prehistoric period. Even barbaric man feels +the need of self-expression, and strives to make his ideas +manifest to other men by pictorial signs. The cave-dwellers +scratched pictures of men and animals on the surface of a +reindeer horn or mammoth tusk as mementos of his prowess. The +American Indian does essentially the same thing to-day, making +pictures that crudely record his successes in war and the chase. +The Northern Indian had got no farther than this when the white +man discovered America; but the Aztecs of the Southwest and the +Maya people of Yucatan had carried their picture- making to a +much higher state of elaboration.[3] They had developed systems +of pictographs or hieroglyphics that would doubtless in the +course of generations have been elaborated into alphabetical +systems, had not the Europeans cut off the civilization of which +they were the highest exponents. + +What the Aztec and Maya were striving towards in the sixteenth +century A.D., various Oriental nations had attained at least five +or six thousand years earlier. In Egypt at the time of the +pyramid-builders, and in Babylonia at the same epoch, the people +had developed systems of writing that enabled them not merely to +present a limited range of ideas pictorially, but to express in +full elaboration and with finer shades of meaning all the ideas +that pertain to highly cultured existence. The man of that time +made records of military achievements, recorded the transactions +of every-day business life, and gave expression to his moral and +spiritual aspirations in a way strangely comparable to the manner +of our own time. He had perfected highly elaborate systems of +writing. + + +EGYPTIAN WRITING + +Of the two ancient systems of writing just referred to as being +in vogue at the so-called dawnings of history, the more +picturesque and suggestive was the hieroglyphic system of the +Egyptians. This is a curiously conglomerate system of writing, +made up in part of symbols reminiscent of the crudest stages of +picture-writing, in part of symbols having the phonetic value of +syllables, and in part of true alphabetical letters. In a word, +the Egyptian writing represents in itself the elements of the +various stages through which the art of writing has developed.[4] +We must conceive that new features were from time to time added +to it, while the old features, curiously enough, were not given +up. + +Here, for example, in the midst of unintelligible lines and +pot-hooks, are various pictures that are instantly recognizable +as representations of hawks, lions, ibises, and the like. It can +hardly be questioned that when these pictures were first used +calligraphically they were meant to represent the idea of a bird +or animal. In other words, the first stage of picture-writing did +not go beyond the mere representation of an eagle by the picture +of an eagle. But this, obviously, would confine the presentation +of ideas within very narrow limits. In due course some inventive +genius conceived the thought of symbolizing a picture. To him the +outline of an eagle might represent not merely an actual bird, +but the thought of strength, of courage, or of swift progress. +Such a use of symbols obviously extends the range of utility of a +nascent art of writing. Then in due course some wonderful +psychologist--or perhaps the joint efforts of many generations of +psychologists--made the astounding discovery that the human +voice, which seems to flow on in an unbroken stream of endlessly +varied modulations and intonations, may really be analyzed into a +comparatively limited number of component sounds--into a few +hundreds of syllables. That wonderful idea conceived, it was only +a matter of time until it would occur to some other enterprising +genius that by selecting an arbitrary symbol to represent each +one of these elementary sounds it would be possible to make a +written record of the words of human speech which could be +reproduced--rephonated--by some one who had never heard the words +and did not know in advance what this written record contained. +This, of course, is what every child learns to do now in the +primer class, but we may feel assured that such an idea never +occurred to any human being until the peculiar forms of +pictographic writing just referred to had been practised for many +centuries. Yet, as we have said, some genius of prehistoric Egypt +conceived the idea and put it into practical execution, and the +hieroglyphic writing of which the Egyptians were in full +possession at the very beginning of what we term the historical +period made use of this phonetic system along with the +ideographic system already described. + +So fond were the Egyptians of their pictorial symbols used +ideographically that they clung to them persistently throughout +the entire period of Egyptian history. They used symbols as +phonetic equivalents very frequently, but they never learned to +depend upon them exclusively. The scribe always interspersed his +phonetic signs with some other signs intended as graphic aids. +After spelling a word out in full, he added a picture, sometimes +even two or three pictures, representative of the individual +thing, or at least of the type of thing to which the word +belongs. Two or three illustrations will make this clear. + +Thus qeften, monkey, is spelled out in full, but the picture of a +monkey is added as a determinative; second, qenu, cavalry, after +being spelled, is made unequivocal by the introduction of a +picture of a horse; third, temati, wings, though spelled +elaborately, has pictures of wings added; and fourth, tatu, +quadrupeds, after being spelled, has a picture of a quadruped, +and then the picture of a hide, which is the usual determinative +of a quadruped, followed by three dashes to indicate the plural +number. + +It must not be supposed, however, that it was a mere whim which +led the Egyptians to the use of this system of determinatives. +There was sound reason back of it. It amounted to no more than +the expedient we adopt when we spell "to," "two," or "too," in +indication of a single sound with three different meanings. The +Egyptian language abounds in words having more than one meaning, +and in writing these it is obvious that some means of distinction +is desirable. The same thing occurs even more frequently in the +Chinese language, which is monosyllabic. The Chinese adopt a more +clumsy expedient, supplying a different symbol for each of the +meanings of a syllable; so that while the actual word-sounds of +their speech are only a few hundreds in number, the characters of +their written language mount high into the thousands. + + +BABYLONIAN WRITING + +While the civilization of the Nile Valley was developing this +extraordinary system of hieroglyphics, the inhabitants of +Babylonia were practising the art of writing along somewhat +different lines. It is certain that they began with +picture-making, and that in due course they advanced to the +development of the syllabary; but, unlike their Egyptian cousins, +the men of Babylonia saw fit to discard the old system when they +had perfected a better one.[5] So at a very early day their +writing--as revealed to us now through the recent +excavations--had ceased to have that pictorial aspect which +distinguishes the Egyptian script. What had originally been +pictures of objects--fish, houses, and the like--had come to be +represented by mere aggregations of wedge-shaped marks. As the +writing of the Babvlonians was chiefly inscribed on soft clay, +the adaptation of this wedge-shaped mark in lieu of an ordinary +line was probably a mere matter of convenience, since the +sharp-cornered implement used in making the inscription naturally +made a wedge-shaped impression in the clay. That, however, is a +detail. The essential thing is that the Babylonian had so fully +analyzed the speech-sounds that he felt entire confidence in +them, and having selected a sufficient number of conventional +characters--each made up of wedge-shaped lines--to represent all +the phonetic sounds of his language, spelled the words out in +syllables and to some extent dispensed with the determinative +signs which, as we have seen, played so prominent a part in the +Egyptian writing. His cousins the Assyrians used habitually a +system of writing the foundation of which was an elaborate +phonetic syllabary; a system, therefore, far removed from the old +crude pictograph, and in some respects much more developed than +the complicated Egyptian method; yet, after all, a system that +stopped short of perfection by the wide gap that separates the +syllabary from the true alphabet. + +A brief analysis of speech sounds will aid us in understanding +the real nature of the syllabary. Let us take for consideration +the consonantal sound represented by the letter b. A moment's +consideration will make it clear that this sound enters into a +large number of syllables. There are, for example, at least +twenty vowel sounds in the English language, not to speak of +certain digraphs; that is to say, each of the important vowels +has from two to six sounds. Each of these vowel sounds may enter +into combination with the b sound alone to form three syllables; +as ba, ab, bal, be, eb, bel, etc. Thus there are at least sixty +b-sound syllables. But this is not the end, for other consonantal +sounds may be associated in the syllables in such combinations as +bad, bed, bar, bark, cab, etc. As each of the other twenty odd +consonantal sounds may enter into similar combinations, it is +obvious that there are several hundreds of fundamental syllables +to be taken into account in any syllabic system of writing. For +each of these syllables a symbol must be set aside and held in +reserve as the representative of that particular sound. A perfect +syllabary, then, would require some hundred or more of symbols to +represent b sounds alone; and since the sounds for c, d, f, and +the rest are equally varied, the entire syllabary would run into +thousands of characters, almost rivalling in complexity the +Chinese system. But in practice the most perfect syllabary, Such +as that of the Babylonians, fell short of this degree of +precision through ignoring the minor shades of sound; just as our +own alphabet is content to represent some thirty vowel sounds by +five letters, ignoring the fact that a, for example, has really +half a dozen distinct phonetic values. By such slurring of sounds +the syllabary is reduced far below its ideal limits; yet even so +it retains three or four hundred characters. + +In point of fact, such a work as Professor Delitzsch's Assyrian +Grammar[6] presents signs for three hundred and thirty-four +syllables, together with sundry alternative signs and +determinatives to tax the memory of the would-be reader of +Assyrian. Let us take for example a few of the b sounds. It has +been explained that the basis of the Assyrian written character +is a simple wedge-shaped or arrow-head mark. Variously repeated +and grouped, these marks make up the syllabic characters. + +To learn some four hundred such signs as these was the task set, +as an equivalent of learning the a b c's, to any primer class in +old Assyria in the long generations when that land was the +culture Centre of the world. Nor was the task confined to the +natives of Babylonia and Assyria alone. About the fifteenth +century B.C., and probably for a long time before and after that +period, the exceedingly complex syllabary of the Babylonians was +the official means of communication throughout western Asia and +between Asia and Egypt, as we know from the chance discovery of a +collection of letters belonging to the Egyptian king Khun-aten, +preserved at Tel-el-Amarna. In the time of Ramses the Great the +Babylonian writing was in all probability considered by a +majority of the most highly civilized people in the world to be +the most perfect script practicable. Doubtless the average scribe +of the time did not in the least realize the waste of energy +involved in his labors, or ever suspect that there could be any +better way of writing. + +Yet the analysis of any one of these hundreds of syllables into +its component phonetic elements--had any one been genius enough +to make such analysis-- ould have given the key to simpler and +better things. But such an analysis was very hard to make, as the +sequel shows. Nor is the utility of such an analysis +self-evident, as the experience of the Egyptians proved. The +vowel sound is so intimately linked with the consonant--the +con-sonant, implying this intimate relation in its very +name--that it seemed extremely difficult to give it individual +recognition. To set off the mere labial beginning of the sound by +itself, and to recognize it as an all-essential element of +phonation, was the feat at which human intelligence so long +balked. The germ of great things lay in that analysis. It was a +process of simplification, and all art development is from the +complex to the simple. Unfortunately, however, it did not seem a +simplification, but rather quite the reverse. We may well suppose +that the idea of wresting from the syllabary its secret of +consonants and vowels, and giving to each consonantal sound a +distinct sign, seemed a most cumbersome and embarrassing +complication to the ancient scholars--that is to say, after the +time arrived when any one gave such an idea expression. We can +imagine them saying: "You will oblige us to use four signs +instead of one to write such an elementary syllable as 'bard,' +for example. Out upon such endless perplexity!" Nor is such a +suggestion purely gratuitous, for it is an historical fact that +the old syllabary continued to be used in Babylon hundreds of +years after the alphabetical system had been introduced.[7] +Custom is everything in establishing our prejudices. The Japanese +to-day rebel against the introduction of an alphabet, thinking it +ambiguous. + +Yet, in the end, conservatism always yields, and so it was with +opposition to the alphabet. Once the idea of the consonant had +been firmly grasped, the old syllabary was doomed, though +generations of time might be required to complete the +obsequies--generations of time and the influence of a new nation. +We have now to inquire how and by whom this advance was made. + + +THE ALPHABET ACHIEVED + +We cannot believe that any nation could have vaulted to the final +stage of the simple alphabetical writing without tracing the +devious and difficult way of the pictograph and the syllabary. It +is possible, however, for a cultivated nation to build upon the +shoulders of its neighbors, and, profiting by the experience of +others, to make sudden leaps upward and onward. And this is +seemingly what happened in the final development of the art of +writing. For while the Babylonians and Assyrians rested content +with their elaborate syllabary, a nation on either side of them, +geographically speaking, solved the problem, which they perhaps +did not even recognize as a problem; wrested from their syllabary +its secret of consonants and vowels, and by adopting an arbitrary +sign for each consonantal sound, produced that most wonderful of +human inventions, the alphabet. + +The two nations credited with this wonderful achievement are the +Phoenicians and the Persians. But it is not usually conceded that +the two are entitled to anything like equal credit. The Persians, +probably in the time of Cyrus the Great, used certain characters +of the Babylonian script for the construction of an alphabet; but +at this time the Phoenician alphabet had undoubtedly been in use +for some centuries, and it is more than probable that the Persian +borrowed his idea of an alphabet from a Phoenician source. And +that, of course, makes all the difference. Granted the idea of an +alphabet, it requires no great reach of constructive genius to +supply a set of alphabetical characters; though even here, it may +be added parenthetically, a study of the development of alphabets +will show that mankind has all along had a characteristic +propensity to copy rather than to invent. + +Regarding the Persian alphabet-maker, then, as a copyist rather +than a true inventor, it remains to turn attention to the +Phoenician source whence, as is commonly believed, the original +alphabet which became "the mother of all existing alphabets" came +into being. It must be admitted at the outset that evidence for +the Phoenician origin of this alphabet is traditional rather than +demonstrative. The Phoenicians were the great traders of +antiquity; undoubtedly they were largely responsible for the +transmission of the alphabet from one part of the world to +another, once it had been invented. Too much credit cannot be +given them for this; and as the world always honors him who makes +an idea fertile rather than the originator of the idea, there can +be little injustice in continuing to speak of the Phoenicians as +the inventors of the alphabet. But the actual facts of the case +will probably never be known. For aught we know, it may have been +some dreamy-eyed Israelite, some Babylonian philosopher, some +Egyptian mystic, perhaps even some obscure Cretan, who gave to +the hard-headed Phoenician trader this conception of a +dismembered syllable with its all-essential, elemental, +wonder-working consonant. But it is futile now to attempt even to +surmise on such unfathomable details as these. Suffice it that +the analysis was made; that one sign and no more was adopted for +each consonantal sound of the Semitic tongue, and that the entire +cumbersome mechanism of the Egyptian and Babylonian writing +systems was rendered obsolescent. These systems did not yield at +once, to be sure; all human experience would have been set at +naught had they done so. They held their own, and much more than +held their own, for many centuries. After the Phoenicians as a +nation had ceased to have importance; after their original script +had been endlessly modified by many alien nations; after the +original alphabet had made the conquest of all civilized Europe +and of far outlying portions of the Orient--the Egyptian and +Babylonian scribes continued to indite their missives in the same +old pictographs and syllables. + +The inventive thinker must have been struck with amazement when, +after making the fullest analysis of speech-sounds of which he +was capable, he found himself supplied with only a score or so of +symbols. Yet as regards the consonantal sounds he had exhausted +the resources of the Semitic tongue. As to vowels, he scarcely +considered them at all. It seemed to him sufficient to use one +symbol for each consonantal sound. This reduced the hitherto +complex mechanism of writing to so simple a system that the +inventor must have regarded it with sheer delight. On the other +hand, the conservative scholar doubtless thought it distinctly +ambiguous. In truth, it must be admitted that the system was +imperfect. It was a vast improvement on the old syllabary, but it +had its drawbacks. Perhaps it had been made a bit too simple; +certainly it should have had symbols for the vowel sounds as well +as for the consonants. Nevertheless, the vowel-lacking alphabet +seems to have taken the popular fancy, and to this day Semitic +people have never supplied its deficiencies save with certain +dots and points. + +Peoples using the Aryan speech soon saw the defect, and the +Greeks supplied symbols for several new sounds at a very early +day.[8] But there the matter rested, and the alphabet has +remained imperfect. For the purposes of the English language +there should certainly have been added a dozen or more new +characters. It is clear, for example, that, in the interest of +explicitness, we should have a separate symbol for the vowel +sound in each of the following syllables: bar, bay, bann, ball, +to cite a single illustration. + +There is, to be sure, a seemingly valid reason for not extending +our alphabet, in the fact that in multiplying syllables it would +be difficult to select characters at once easy to make and +unambiguous. Moreover, the conservatives might point out, with +telling effect, that the present alphabet has proved admirably +effective for about three thousand years. Yet the fact that our +dictionaries supply diacritical marks for some thirty vowels +sounds to indicate the pronunciation of the words of our +every-day speech, shows how we let memory and guessing do the +work that might reasonably be demanded of a really complete +alphabet. But, whatever its defects, the existing alphabet is a +marvellous piece of mechanism, the result of thousands of years +of intellectual effort. It is, perhaps without exception, the +most stupendous invention of the human intellect within +historical times--an achievement taking rank with such great +prehistoric discoveries as the use of articulate speech, the +making of a fire, and the invention of stone implements, of the +wheel and axle, and of picture-writing. It made possible for the +first time that education of the masses upon which all later +progress of civilization was so largely to depend. + + + +V. THE BEGINNINGS OF GREEK SCIENCE + +Herodotus, the Father of History, tells us that once upon a +time--which time, as the modern computator shows us, was about +the year 590 B.C. --a war had risen between the Lydians and the +Medes and continued five years. "In these years the Medes often +discomfited the Lydians and the Lydians often discomfited the +Medes (and among other things they fought a battle by night); and +yet they still carried on the war with equally balanced +fortitude. In the sixth year a battle took place in which it +happened, when the fight had begun, that suddenly the day became +night. And this change of the day Thales, the Milesian, had +foretold to the Ionians, laying down as a limit this very year in +which the change took place. The Lydians, however, and the Medes, +when they saw that it had become night instead of day, ceased +from their fighting and were much more eager, both of them, that +peace should be made between them." + +This memorable incident occurred while Alyattus, father of +Croesus, was king of the Lydians. The modern astronomer, +reckoning backward, estimates this eclipse as occurring probably +May 25th, 585 B.C. The date is important as fixing a mile-stone +in the chronology of ancient history, but it is doubly memorable +because it is the first recorded instance of a predicted eclipse. +Herodotus, who tells the story, was not born until about one +hundred years after the incident occurred, but time had not +dimmed the fame of the man who had performed the necromantic feat +of prophecy. Thales, the Milesian, thanks in part at least to +this accomplishment, had been known in life as first on the list +of the Seven Wise Men of Greece, and had passed into history as +the father of Greek philosophy. We may add that he had even found +wider popular fame through being named by Hippolytus, and then by +Father aesop, as the philosopher who, intent on studying the +heavens, fell into a well; "whereupon," says Hippolytus, "a +maid-servant named Thratta laughed at him and said, 'In his +search for things in the sky he does not see what is at his +feet.' " + +Such citations as these serve to bring vividly to mind the fact +that we are entering a new epoch of thought. Hitherto our studies +have been impersonal. Among Egyptians and Babylonians alike we +have had to deal with classes of scientific records, but we have +scarcely come across a single name. Now, however, we shall begin +to find records of the work of individual investigators. In +general, from now on, we shall be able to trace each great idea, +if not to its originator, at least to some one man of genius who +was prominent in bringing it before the world. The first of these +vitalizers of thought, who stands out at the beginnings of Greek +history, is this same Thales, of Miletus. His is not a very +sharply defined personality as we look back upon it, and we can +by no means be certain that all the discoveries which are +ascribed to him are specifically his. Of his individuality as a +man we know very little. It is not even quite certain as to where +he was born; Miletus is usually accepted as his birthplace, but +one tradition makes him by birth a Phenician. It is not at all in +question, however, that by blood he was at least in part an +Ionian Greek. It will be recalled that in the seventh century +B.C., when Thales was born--and for a long time thereafter--the +eastern shores of the aegean Sea were quite as prominently the +centre of Greek influence as was the peninsula of Greece itself. +Not merely Thales, but his followers and disciples, Anaximander +and Anaximenes, were born there. So also was Herodotas, the +Father of History, not to extend the list. There is nothing +anomalous, then, in the fact that Thales, the father of Greek +thought, was born and passed his life on soil that was not +geographically a part of Greece; but the fact has an important +significance of another kind. Thanks to his environment, Thales +was necessarily brought more or less in contact with Oriental +ideas. There was close commercial contact between the land of his +nativity and the great Babylonian capital off to the east, as +also with Egypt. Doubtless this association was of influence in +shaping the development of Thales's mind. Indeed, it was an +accepted tradition throughout classical times that the Milesian +philosopher had travelled in Egypt, and had there gained at least +the rudiments of his knowledge of geometry. In the fullest sense, +then, Thales may be regarded as representing a link in the chain +of thought connecting the learning of the old Orient with the +nascent scholarship of the new Occident. Occupying this position, +it is fitting that the personality of Thales should partake +somewhat of mystery; that the scene may not be shifted too +suddenly from the vague, impersonal East to the individualism of +Europe. + +All of this, however, must not be taken as casting any doubt upon +the existence of Thales as a real person. Even the dates of his +life--640 to 546 B.C.--may be accepted as at least approximately +trustworthy; and the specific discoveries ascribed to him +illustrate equally well the stage of development of Greek +thought, whether Thales himself or one of his immediate disciples +were the discoverer. We have already mentioned the feat which was +said to have given Thales his great reputation. That Thales was +universally credited with having predicted the famous eclipse is +beyond question. That he actually did predict it in any precise +sense of the word is open to doubt. At all events, his prediction +was not based upon any such precise knowledge as that of the +modern astronomer. There is, indeed, only one way in which he +could have foretold the eclipse, and that is through knowledge of +the regular succession of preceding eclipses. But that knowledge +implies access on the part of some one to long series of records +of practical observations of the heavens. Such records, as we +have seen, existed in Egypt and even more notably in Babylonia. +That these records were the source of the information which +established the reputation of Thales is an unavoidable inference. +In other words, the magical prevision of the father of Greek +thought was but a reflex of Oriental wisdom. Nevertheless, it +sufficed to establish Thales as the father of Greek astronomy. In +point of fact, his actual astronomical attainments would appear +to have been meagre enough. There is nothing to show that he +gained an inkling of the true character of the solar system. He +did not even recognize the sphericity of the earth, but held, +still following the Oriental authorities, that the world is a +flat disk. Even his famous cosmogonic guess, according to which +water is the essence of all things and the primordial element out +of which the earth was developed, is but an elaboration of the +Babylonian conception. + +When we turn to the other field of thought with which the name of +Thales is associated--namely, geometry--we again find evidence of +the Oriental influence. The science of geometry, Herodotus +assures us, was invented in Egypt. It was there an eminently +practical science, being applied, as the name literally suggests, +to the measurement of the earth's surface. Herodotus tells us +that the Egyptians were obliged to cultivate the science because +the periodical inundations washed away the boundary-lines between +their farms. The primitive geometer, then, was a surveyor. The +Egyptian records, as now revealed to us, show that the science +had not been carried far in the land of its birth. The Egyptian +geometer was able to measure irregular pieces of land only +approximately. He never fully grasped the idea of the +perpendicular as the true index of measurement for the triangle, +but based his calculations upon measurements of the actual side +of that figure. Nevertheless, he had learned to square the circle +with a close approximation to the truth, and, in general, his +measurement sufficed for all his practical needs. Just how much +of the geometrical knowledge which added to the fame of Thales +was borrowed directly from the Egyptians, and how much he +actually created we cannot be sure. Nor is the question raised in +disparagement of his genius. Receptivity is the first +prerequisite to progressive thinking, and that Thales reached out +after and imbibed portions of Oriental wisdom argues in itself +for the creative character of his genius. Whether borrower of +originator, however, Thales is credited with the expression of +the following geometrical truths: + +1. That the circle is bisected by its diameter. + +2. That the angles at the base of an isosceles triangle are +equal. + +3. That when two straight lines cut each other the vertical +opposite angles are equal. + +4. That the angle in a semicircle is a right angle. + +5. That one side and one acute angle of a right-angle triangle +determine the other sides of the triangle. + +It was by the application of the last of these principles that +Thales is said to have performed the really notable feat of +measuring the distance of a ship from the shore, his method being +precisely the same in principle as that by which the guns are +sighted on a modern man-of-war. Another practical demonstration +which Thales was credited with making, and to which also his +geometrical studies led him, was the measurement of any tall +object, such as a pyramid or building or tree, by means of its +shadow. The method, though simple enough, was ingenious. It +consisted merely in observing the moment of the day when a +perpendicular stick casts a shadow equal to its own length. +Obviously the tree or monument would also cast a shadow equal to +its own height at the same moment. It remains then but to measure +the length of this shadow to determine the height of the object. +Such feats as this evidence the practicality of the genius of +Thales. They suggest that Greek science, guided by imagination, +was starting on the high-road of observation. We are told that +Thales conceived for the first time the geometry of lines, and +that this, indeed, constituted his real advance upon the +Egyptians. We are told also that he conceived the eclipse of the +sun as a purely natural phenomenon, and that herein lay his +advance upon the Chaldean point of view. But if this be true +Thales was greatly in advance of his time, for it will be +recalled that fully two hundred years later the Greeks under +Nicias before Syracuse were so disconcerted by the appearance of +an eclipse, which was interpreted as a direct omen and warning, +that Nicias threw away the last opportunity to rescue his army. +Thucydides, it is true, in recording this fact speaks +disparagingly of the superstitious bent of the mind of Nicias, +but Thucydides also was a man far in advance of his time. + +All that we know of the psychology of Thales is summed up in the +famous maxim, "Know thyself," a maxim which, taken in connection +with the proven receptivity of the philosopher's mind, suggests +to us a marvellously rounded personality. + +The disciples or successors of Thales, Anaximander and +Anaximenes, were credited with advancing knowledge through the +invention or introduction of the sundial. We may be sure, +however, that the gnomon, which is the rudimentary sundial, had +been known and used from remote periods in the Orient, and the +most that is probable is that Anaximander may have elaborated +some special design, possibly the bowl- shaped sundial, through +which the shadow of the gnomon would indicate the time. The same +philosopher is said to have made the first sketch of a +geographical map, but this again is a statement which modern +researches have shown to be fallacious, since a Babylonian +attempt at depicting the geography of the world is still +preserved to us on a clay tablet. Anaximander may, however, have +been the first Greek to make an attempt of this kind. Here again +the influence of Babylonian science upon the germinating Western +thought is suggested. + +It is said that Anaximander departed from Thales's conception of +the earth, and, it may be added, from the Babylonian conception +also, in that he conceived it as a cylinder, or rather as a +truncated cone, the upper end of which is the habitable portion. +This conception is perhaps the first of these guesses through +which the Greek mind attempted to explain the apparent fixity of +the earth. To ask what supports the earth in space is most +natural, but the answer given by Anaximander, like that more +familiar Greek solution which transformed the cone, or cylinder, +into the giant Atlas, is but another illustration of that +substitution of unwarranted inference for scientific induction +which we have already so often pointed out as characteristic of +the primitive stages of thought. + +Anaximander held at least one theory which, as vouched for by +various copyists and commentators, entitles him to be considered +perhaps the first teacher of the idea of organic evolution. +According to this idea, man developed from a fishlike ancestor, +"growing up as sharks do until able to help himself and then +coming forth on dry land."[1] The thought here expressed finds +its germ, perhaps, in the Babylonian conception that everything +came forth from a chaos of waters. Yet the fact that the thought +of Anaximander has come down to posterity through such various +channels suggests that the Greek thinker had got far enough away +from the Oriental conception to make his view seem to his +contemporaries a novel and individual one. Indeed, nothing we +know of the Oriental line of thought conveys any suggestion of +the idea of transformation of species, whereas that idea is +distinctly formulated in the traditional views of Anaximander. + + + +VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + +Diogenes Laertius tells a story about a youth who, clad in a +purple toga, entered the arena at the Olympian games and asked to +compete with the other youths in boxing. He was derisively denied +admission, presumably because he was beyond the legitimate age +for juvenile contestants. Nothing daunted, the youth entered the +lists of men, and turned the laugh on his critics by coming off +victor. The youth who performed this feat was named Pythagoras. +He was the same man, if we may credit the story, who afterwards +migrated to Italy and became the founder of the famous Crotonian +School of Philosophy; the man who developed the religion of the +Orphic mysteries; who conceived the idea of the music of the +spheres; who promulgated the doctrine of metempsychosis; who +first, perhaps, of all men clearly conceived the notion that this +world on which we live is a ball which moves in space and which +may be habitable on every side. + +A strange development that for a stripling pugilist. But we must +not forget that in the Greek world athletics held a peculiar +place. The chief winner of Olympian games gave his name to an +epoch (the ensuing Olympiad of four years), and was honored +almost before all others in the land. A sound mind in a sound +body was the motto of the day. To excel in feats of strength and +dexterity was an accomplishment that even a philosopher need not +scorn. It will be recalled that aeschylus distinguished himself +at the battle of Marathon; that Thucydides, the greatest of Greek +historians, was a general in the Peloponnesian War; that +Xenophon, the pupil and biographer of Socrates, was chiefly famed +for having led the Ten Thousand in the memorable campaign of +Cyrus the Younger; that Plato himself was credited with having +shown great aptitude in early life as a wrestler. If, then, +Pythagoras the philosopher was really the Pythagoras who won the +boxing contest, we may suppose that in looking back upon this +athletic feat from the heights of his priesthood--for he came to +be almost deified--he regarded it not as an indiscretion of his +youth, but as one of the greatest achievements of his life. Not +unlikely he recalled with pride that he was credited with being +no less an innovator in athletics than in philosophy. At all +events, tradition credits him with the invention of "scientific" +boxing. Was it he, perhaps, who taught the Greeks to strike a +rising and swinging blow from the hip, as depicted in the famous +metopes of the Parthenon? If so, the innovation of Pythagoras was +as little heeded in this regard in a subsequent age as was his +theory of the motion of the earth; for to strike a swinging blow +from the hip, rather than from the shoulder, is a trick which the +pugilist learned anew in our own day. + +But enough of pugilism and of what, at best, is a doubtful +tradition. Our concern is with another "science" than that of the +arena. We must follow the purple-robed victor to Italy--if, +indeed, we be not over-credulous in accepting the tradition--and +learn of triumphs of a different kind that have placed the name +of Pythagoras high on the list of the fathers of Grecian thought. +To Italy? Yes, to the western limits of the Greek world. Here it +was, beyond the confines of actual Greek territory, that Hellenic +thought found its second home, its first home being, as we have +seen, in Asia Minor. Pythagoras, indeed, to whom we have just +been introduced, was born on the island of Samos, which lies near +the coast of Asia Minor, but he probably migrated at an early day +to Crotona, in Italy. There he lived, taught, and developed his +philosophy until rather late in life, when, having incurred the +displeasure of his fellow-citizens, he suffered the not unusual +penalty of banishment. + +Of the three other great Italic leaders of thought of the early +period, Xenophanes came rather late in life to Elea and founded +the famous Eleatic School, of which Parmenides became the most +distinguished ornament. These two were Ionians, and they lived in +the sixth century before our era. Empedocles, the Sicilian, was +of Doric origin. He lived about the middle of the fifth century +B.C., at a time, therefore, when Athens had attained a position +of chief glory among the Greek states; but there is no evidence +that Empedocles ever visited that city, though it was rumored +that he returned to the Peloponnesus to die. The other great +Italic philosophers just named, living, as we have seen, in the +previous century, can scarcely have thought of Athens as a centre +of Greek thought. Indeed, the very fact that these men lived in +Italy made that peninsula, rather than the mother-land of Greece, +the centre of Hellenic influence. But all these men, it must +constantly be borne in mind, were Greeks by birth and language, +fully recognized as such in their own time and by posterity. Yet +the fact that they lived in a land which was at no time a part of +the geographical territory of Greece must not be forgotten. They, +or their ancestors of recent generations, had been pioneers among +those venturesome colonists who reached out into distant portions +of the world, and made homes for themselves in much the same +spirit in which colonists from Europe began to populate America +some two thousand years later. In general, colonists from the +different parts of Greece localized themselves somewhat +definitely in their new homes; yet there must naturally have been +a good deal of commingling among the various families of +pioneers, and, to a certain extent, a mingling also with the +earlier inhabitants of the country. This racial mingling, +combined with the well-known vitalizing influence of the pioneer +life, led, we may suppose, to a more rapid and more varied +development than occurred among the home-staying Greeks. In proof +of this, witness the remarkable schools of philosophy which, as +we have seen, were thus developed at the confines of the Greek +world, and which were presently to invade and, as it were, take +by storm the mother-country itself. + +As to the personality of these pioneer philosophers of the West, +our knowledge is for the most part more or less traditional. What +has been said of Thales may be repeated, in the main, regarding +Pythagoras, Parmenides, and Empedocles. That they were real +persons is not at all in question, but much that is merely +traditional has come to be associated with their names. +Pythagoras was the senior, and doubtless his ideas may have +influenced the others more or less, though each is usually spoken +of as the founder of an independent school. Much confusion has +all along existed, however, as to the precise ideas which were to +be ascribed to each of the leaders. Numberless commentators, +indeed, have endeavored to pick out from among the traditions of +antiquity, aided by such fragments, of the writing of the +philosophers as have come down to us, the particular ideas that +characterized each thinker, and to weave these ideas into +systems. But such efforts, notwithstanding the mental energy that +has been expended upon them, were, of necessity, futile, since, +in the first place, the ancient philosophers themselves did not +specialize and systematize their ideas according to modern +notions, and, in the second place, the records of their +individual teachings have been too scantily preserved to serve +for the purpose of classification. It is freely admitted that +fable has woven an impenetrable mesh of contradictions about the +personalities of these ancient thinkers, and it would be folly to +hope that this same artificer had been less busy with their +beliefs and theories. When one reads that Pythagoras advocated an +exclusively vegetable diet, yet that he was the first to train +athletes on meat diet; that he sacrificed only inanimate things, +yet that he offered up a hundred oxen in honor of his great +discovery regarding the sides of a triangle, and such like +inconsistencies in the same biography, one gains a realizing +sense of the extent to which diverse traditions enter into the +story as it has come down to us. And yet we must reflect that +most men change their opinions in the course of a long lifetime, +and that the antagonistic reports may both be true. + +True or false, these fables have an abiding interest, since they +prove the unique and extraordinary character of the personality +about which they are woven. The alleged witticisms of a Whistler, +in our own day, were doubtless, for the most part, quite unknown +to Whistler himself, yet they never would have been ascribed to +him were they not akin to witticisms that he did originate--were +they not, in short, typical expressions of his personality. And +so of the heroes of the past. "It is no ordinary man," said +George Henry Lewes, speaking of Pythagoras, "whom fable exalts +into the poetic region. Whenever you find romantic or miraculous +deeds attributed, be certain that the hero was great enough to +maintain the weight of the crown of this fabulous glory."[1] We +may not doubt, then, that Pythagoras, Parmenides, and Empedocles, +with whose names fable was so busy throughout antiquity, were men +of extraordinary personality. We are here chiefly concerned, +however, neither with the personality of the man nor yet with the +precise doctrines which each one of them taught. A knowledge of +the latter would be interesting were it attainable, but in the +confused state of the reports that have come down to us we cannot +hope to be able to ascribe each idea with precision to its proper +source. At best we can merely outline, even here not too +precisely, the scientific doctrines which the Italic philosophers +as a whole seem to have advocated. + +First and foremost, there is the doctrine that the earth is a +sphere. Pythagoras is said to have been the first advocate of +this theory; but, unfortunately, it is reported also that +Parmenides was its author. This rivalship for the discovery of an +important truth we shall see repeated over and over in more +recent times. Could we know the whole truth, it would perhaps +appear that the idea of the sphericity of the earth was +originated long before the time of the Greek philosophers. But it +must be admitted that there is no record of any sort to give +tangible support to such an assumption. So far as we can +ascertain, no Egyptian or Babylonian astronomer ever grasped the +wonderful conception that the earth is round. That the Italic +Greeks should have conceived that idea was perhaps not so much +because they were astronomers as because they were practical +geographers and geometers. Pythagoras, as we have noted, was born +at Samos, and, therefore, made a relatively long sea voyage in +passing to Italy. Now, as every one knows, the most simple and +tangible demonstration of the convexity of the earth's surface is +furnished by observation of an approaching ship at sea. On a +clear day a keen eye may discern the mast and sails rising +gradually above the horizon, to be followed in due course by the +hull. Similarly, on approaching the shore, high objects become +visible before those that lie nearer the water. It is at least a +plausible supposition that Pythagoras may have made such +observations as these during the voyage in question, and that +therein may lie the germ of that wonderful conception of the +world as a sphere. + +To what extent further proof, based on the fact that the earth's +shadow when the moon is eclipsed is always convex, may have been +known to Pythagoras we cannot say. There is no proof that any of +the Italic philosophers made extensive records of astronomical +observations as did the Egyptians and Babylonians; but we must +constantly recall that the writings of classical antiquity have +been almost altogether destroyed. The absence of astronomical +records is, therefore, no proof that such records never existed. +Pythagoras, it should be said, is reported to have travelled in +Egypt, and he must there have gained an inkling of astronomical +methods. Indeed, he speaks of himself specifically, in a letter +quoted by Diogenes, as one who is accustomed to study astronomy. +Yet a later sentence of the letter, which asserts that the +philosopher is not always occupied about speculations of his own +fancy, suggesting, as it does, the dreamer rather than the +observer, gives us probably a truer glimpse into the +philosopher's mind. There is, indeed, reason to suppose that the +doctrine of the sphericity of the earth appealed to Pythagoras +chiefly because it accorded with his conception that the sphere +is the most perfect solid, just as the circle is the most perfect +plane surface. Be that as it may, the fact remains that we have +here, as far as we can trace its origin, the first expression of +the scientific theory that the earth is round. Had the Italic +philosophers accomplished nothing more than this, their +accomplishment would none the less mark an epoch in the progress +of thought. + +That Pythagoras was an observer of the heavens is further +evidenced by the statement made by Diogenes, on the authority of +Parmenides, that Pythagoras was the first person who discovered +or asserted the identity of Hesperus and Lucifer--that is to say, +of the morning and the evening star. This was really a remarkable +discovery, and one that was no doubt instrumental later on in +determining that theory of the mechanics of the heavens which we +shall see elaborated presently. To have made such a discovery +argues again for the practicality of the mind of Pythagoras. His, +indeed, would seem to have been a mind in which practical +common-sense was strangely blended with the capacity for wide and +imaginative generalization. As further evidence of his +practicality, it is asserted that he was the first person who +introduced measures and weights among the Greeks, this assertion +being made on the authority of Aristoxenus. It will be observed +that he is said to have introduced, not to have invented, weights +and measures, a statement which suggests a knowledge on the part +of the Greeks that weights and measures were previously employed +in Egypt and Babylonia. + +The mind that could conceive the world as a sphere and that +interested itself in weights and measures was, obviously, a mind +of the visualizing type. It is characteristic of this type of +mind to be interested in the tangibilities of geometry, hence it +is not surprising to be told that Pythagoras "carried that +science to perfection." The most famous discovery of Pythagoras +in this field was that the square of the hypotenuse of a +right-angled triangle is equal to the squares of the other sides +of the triangle. We have already noted the fable that his +enthusiasm over this discovery led him to sacrifice a hecatomb. +Doubtless the story is apocryphal, but doubtless, also, it +expresses the truth as to the fervid joy with which the +philosopher must have contemplated the results of his creative +imagination. + +No line alleged to have been written by Pythagoras has come down +to us. We are told that he refrained from publishing his +doctrines, except by word of mouth. "The Lucanians and the +Peucetians, and the Messapians and the Romans," we are assured, +"flocked around him, coming with eagerness to hear his +discourses; no fewer than six hundred came to him every night; +and if any one of them had ever been permitted to see the master, +they wrote of it to their friends as if they had gained some +great advantage." Nevertheless, we are assured that until the +time of Philolaus no doctrines of Pythagoras were ever published, +to which statement it is added that "when the three celebrated +books were published, Plato wrote to have them purchased for him +for a hundred minas."[2] But if such books existed, they are lost +to the modern world, and we are obliged to accept the assertions +of relatively late writers as to the theories of the great +Crotonian. + +Perhaps we cannot do better than quote at length from an +important summary of the remaining doctrines of Pythagoras, which +Diogenes himself quoted from the work of a predecessor.[3] +Despite its somewhat inchoate character, this summary is a most +remarkable one, as a brief analysis of its contents will show. It +should be explained that Alexander (whose work is now lost) is +said to have found these dogmas set down in the commentaries of +Pythagoras. If this assertion be accepted, we are brought one +step nearer the philosopher himself. The summary is as follows: + + +"That the monad was the beginning of everything. From the monad +proceeds an indefinite duad, which is subordinate to the monad as +to its cause. That from the monad and the indefinite duad proceed +numbers. And from numbers signs. And from these last, lines of +which plane figures consist. And from plane figures are derived +solid bodies. And from solid bodies sensible bodies, of which +last there are four elements--fire, water, earth, and air. And +that the world, which is indued with life and intellect, and +which is of a spherical figure, having the earth, which is also +spherical, and inhabited all over in its centre,[4] results from +a combination of these elements, and derives its motion from +them; and also that there are antipodes, and that what is below, +as respects us, is above in respect of them. + +"He also taught that light and darkness, and cold and heat, and +dryness and moisture, were equally divided in the world; and that +while heat was predominant it was summer; while cold had the +mastery, it was winter; when dryness prevailed, it was spring; +and when moisture preponderated, winter. And while all these +qualities were on a level, then was the loveliest season of the +year; of which the flourishing spring was the wholesome period, +and the season of autumn the most pernicious one. Of the day, he +said that the flourishing period was the morning, and the fading +one the evening; on which account that also was the least healthy +time. + +"Another of his theories was that the air around the earth was +immovable and pregnant with disease, and that everything in it +was mortal; but that the upper air was in perpetual motion, and +pure and salubrious, and that everything in that was immortal, +and on that account divine. And that the sun and the moon and the +stars were all gods; for in them the warm principle predominates +which is the cause of life. And that the moon derives its light +from the sun. And that there is a relationship between men and +the gods, because men partake of the divine principle; on which +account, also, God exercises his providence for our advantage. +Also, that Fate is the cause of the arrangement of the world both +generally and particularly. Moreover, that a ray from the sun +penetrated both the cold aether and the dense aether; and they +call the air the cold aether, and the sea and moisture they call +the dense aether. And this ray descends into the depths, and in +this way vivifies everything. And everything which partakes of +the principle of heat lives, on which account, also, plants are +animated beings; but that all living things have not necessarily +souls. And that the soul is a something tom off from the aether, +both warm and cold, from its partaking of the cold aether. And +that the soul is something different from life. Also, that it is +immortal, because that from which it has been detached is +immortal. + +"Also, that animals are born from one another by seeds, and that +it is impossible for there to be any spontaneous production by +the earth. And that seed is a drop from the brain which contains +in itself a warm vapor; and that when this is applied to the womb +it transmits virtue and moisture and blood from the brain, from +which flesh and sinews and bones and hair and the whole body are +produced. And from the vapor is produced the soul, and also +sensation. And that the infant first becomes a solid body at the +end of forty days; but, according to the principles of harmony, +it is not perfect till seven, or perhaps nine, or at most ten +months, and then it is brought forth. And that it contains in +itself all the principles of life, which are all connected +together, and by their union and combination form a harmonious +whole, each of them developing itself at the appointed time. + +"The senses in general, and especially the sight, are a vapor of +excessive warmth, and on this account a man is said to see +through air and through water. For the hot principle is opposed +by the cold one; since, if the vapor in the eyes were cold, it +would have the same temperature as the air, and so would be +dissipated. As it is, in some passages he calls the eyes the +gates of the sun; and he speaks in a similar manner of hearing +and of the other senses. + +"He also says that the soul of man is divided into three parts: +into intuition and reason and mind, and that the first and last +divisions are found also in other animals, but that the middle +one, reason, is only found in man. And that the chief abode of +the soul is in those parts of the body which are between the +heart and the brain. And that that portion of it which is in the +heart is the mind; but that deliberation and reason reside in the +brain. + +Moreover, that the senses are drops from them; and that the +reasoning sense is immortal, but the others are mortal. And that +the soul is nourished by the blood; and that reasons are the +winds of the soul. That it is invisible, and so are its reasons, +since the aether itself is invisible. That the links of the soul +are the veins and the arteries and the nerves. But that when it +is vigorous, and is by itself in a quiescent state, then its +links are words and actions. That when it is cast forth upon the +earth it wanders about, resembling the body. Moreover, that +Mercury is the steward of the souls, and that on this account he +has the name of Conductor, and Commercial, and Infernal, since it +is he who conducts the souls from their bodies, and from earth +and sea; and that he conducts the pure souls to the highest +region, and that he does not allow the impure ones to approach +them, nor to come near one another, but commits them to be bound +in indissoluble fetters by the Furies. The Pythagoreans also +assert that the whole air is full of souls, and that these are +those which are accounted daemons and heroes. Also, that it is by +them that dreams are sent among men, and also the tokens of +disease and health; these last, too, being sent not only to men, +but to sheep also, and other cattle. Also that it is they who are +concerned with purifications and expiations and all kinds of +divination and oracular predictions, and things of that kind."[5] + + +A brief consideration of this summary of the doctrines of +Pythagoras will show that it at least outlines a most +extraordinary variety of scientific ideas. (1) There is suggested +a theory of monads and the conception of the development from +simple to more complex bodies, passing through the stages of +lines, plain figures, and solids to sensible bodies. (2) The +doctrine of the four elements--fire, water, earth, and air--as +the basis of all organisms is put forward. (3) The idea, not +merely of the sphericity of the earth, but an explicit conception +of the antipodes, is expressed. (4) A conception of the sanitary +influence of the air is clearly expressed. (5) An idea of the +problems of generation and heredity is shown, together with a +distinct disavowal of the doctrine of spontaneous generation-- a +doctrine which, it may be added, remained in vogue, nevertheless, +for some twenty-four hundred years after the time of Pythagoras. +(6) A remarkable analysis of mind is made, and a distinction +between animal minds and the human mind is based on this +analysis. The physiological doctrine that the heart is the organ +of one department of mind is offset by the clear statement that +the remaining factors of mind reside in the brain. This early +recognition of brain as the organ of mind must not be forgotten +in our later studies. It should be recalled, however, that a +Crotonian physician, Alemaean, a younger contemporary of +Pythagoras, is also credited with the same theory. (7) A +knowledge of anatomy is at least vaguely foreshadowed in the +assertion that veins, arteries, and nerves are the links of the +soul. In this connection it should be recalled that Pythagoras +was a practical physician. + +As against these scientific doctrines, however, some of them +being at least remarkable guesses at the truth, attention must be +called to the concluding paragraph of our quotation, in which the +old familiar daemonology is outlined, quite after the Oriental +fashion. We shall have occasion to say more as to this phase of +the subject later on. Meantime, before leaving Pythagoras, let us +note that his practical studies of humanity led him to assert the +doctrine that "the property of friends is common, and that +friendship is equality." His disciples, we are told, used to put +all their possessions together in one store and use them in +common. Here, then, seemingly, is the doctrine of communism put +to the test of experiment at this early day. If it seem that +reference to this carries us beyond the bounds of science, it may +be replied that questions such as this will not lie beyond the +bounds of the science of the near future. + + +XENOPHANES AND PARMENIDES + +There is a whimsical tale about Pythagoras, according to which +the philosopher was wont to declare that in an earlier state he +had visited Hades, and had there seen Homer and Hesiod tortured +because of the absurd things they had said about the gods. +Apocrypbal or otherwise, the tale suggests that Pythagoras was an +agnostic as regards the current Greek religion of his time. The +same thing is perhaps true of most of the great thinkers of this +earliest period. But one among them was remembered in later times +as having had a peculiar aversion to the anthropomorphic +conceptions of his fellows. This was Xenophanes, who was born at +Colophon probably about the year 580 B.C., and who, after a life +of wandering, settled finally in Italy and became the founder of +the so-called Eleatic School. + +A few fragments of the philosophical poem in which Xenophanes +expressed his views have come down to us, and these fragments +include a tolerably definite avowal of his faith. "God is one +supreme among gods and men, and not like mortals in body or in +mind," says Xenophanes. Again he asserts that "mortals suppose +that the gods are born (as they themselves are), that they wear +man's clothing and have human voice and body; but," he continues, +"if cattle or lions had hands so as to paint with their hands and +produce works of art as men do, they would paint their gods and +give them bodies in form like their own--horses like horses, +cattle like cattle." Elsewhere he says, with great acumen: "There +has not been a man, nor will there be, who knows distinctly what +I say about the gods or in regard to all things. For even if one +chance for the most part to say what is true, still he would not +know; but every one thinks that he knows."[6] + +In the same spirit Xenophanes speaks of the battles of Titans, of +giants, and of centaurs as "fictions of former ages." All this +tells of the questioning spirit which distinguishes the +scientific investigator. Precisely whither this spirit led him we +do not know, but the writers of a later time have preserved a +tradition regarding a belief of Xenophanes that perhaps entitles +him to be considered the father of geology. Thus Hippolytus +records that Xenophanes studied the fossils to be found in +quarries, and drew from their observation remarkable conclusions. +His words are as follows: "Xenophanes believes that once the +earth was mingled with the sea, but in the course of time it +became freed from moisture; and his proofs are such as these: +that shells are found in the midst of the land and among the +mountains, that in the quarries of Syracuse the imprints of a +fish and of seals had been found, and in Paros the imprint of an +anchovy at some depth in the stone, and in Melite shallow +impressions of all sorts of sea products. He says that these +imprints were made when everything long ago was covered with mud, +and then the imprint dried in the mud. Further, he says that all +men will be destroyed when the earth sinks into the sea and +becomes mud, and that the race will begin anew from the +beginning; and this transformation takes place for all +worlds."[7] Here, then, we see this earliest of paleontologists +studying the fossil-bearing strata of the earth, and drawing from +his observations a marvellously scientific induction. Almost two +thousand years later another famous citizen of Italy, Leonardo da +Vinci, was independently to think out similar conclusions from +like observations. But not until the nineteenth century of our +era, some twenty-four hundred years after the time of Xenophanes, +was the old Greek's doctrine to be accepted by the scientific +world. The ideas of Xenophanes were known to his contemporaries +and, as we see, quoted for a few centuries by his successors, +then they were ignored or quite forgotten; and if any philosopher +of an ensuing age before the time of Leonardo championed a like +rational explanation of the fossils, we have no record of the +fact. The geological doctrine of Xenophanes, then, must be listed +among those remarkable Greek anticipations of nineteenth -century +science which suffered almost total eclipse in the intervening +centuries. + +Among the pupils of Xenophanes was Parmenides, the thinker who +was destined to carry on the work of his master along the same +scientific lines, though at the same time mingling his scientific +conceptions with the mysticism of the poet. We have already had +occasion to mention that Parmenides championed the idea that the +earth is round; noting also that doubts exist as to whether he or +Pythagoras originated this doctrine. No explicit answer to this +question can possibly be hoped for. It seems clear, however, that +for a long time the Italic School, to which both these +philosophers belonged, had a monopoly of the belief in question. +Parmenides, like Pythagoras, is credited with having believed in +the motion of the earth, though the evidence furnished by the +writings of the philosopher himself is not as demonstrative as +one could wish. Unfortunately, the copyists of a later age were +more concerned with metaphysical speculations than with more +tangible things. But as far as the fragmentary references to the +ideas of Parmenides may be accepted, they do not support the idea +of the earth's motion. Indeed, Parmenides is made to say +explicitly, in preserved fragments, that "the world is immovable, +limited, and spheroidal in form."[8] + +Nevertheless, some modern interpreters have found an opposite +meaning in Parmenides. Thus Ritter interprets him as supposing +"that the earth is in the centre spherical, and maintained in +rotary motion by its equiponderance; around it lie certain rings, +the highest composed of the rare element fire, the next lower a +compound of light and darkness, and lowest of all one wholly of +night, which probably indicated to his mind the surface of the +earth, the centre of which again he probably considered to be +fire."[9] But this, like too many interpretations of ancient +thought, appears to read into the fragments ideas which the words +themselves do not warrant. There seems no reason to doubt, +however, that Parmenides actually held the doctrine of the +earth's sphericity. Another glimpse of his astronomical doctrines +is furnished us by a fragment which tells us that he conceived +the morning and the evening stars to be the same, a doctrine +which, as we have seen, was ascribed also to Pythagoras. Indeed, +we may repeat that it is quite impossible to distinguish between +the astronomical doctrines of these two philosophers. + +The poem of Parmenides in which the cosmogonic speculations occur +treats also of the origin of man. The author seems to have had a +clear conception that intelligence depends on bodily organism, +and that the more elaborately developed the organism the higher +the intelligence. But in the interpretation of this thought we +are hampered by the characteristic vagueness of expression, which +may best be evidenced by putting before the reader two English +translations of the same stanza. Here is Ritter's rendering, as +made into English by his translator, Morrison: + + "For exactly as each has the state of his limbs many-jointed, +So invariably stands it with men in their mind and their +reason; For the system of limbs is that which thinketh in +mankind Alike in all and in each: for thought is the +fulness."[10] + +The same stanza is given thus by George Henry Lewes: + + "Such as to each man is the nature of his many-jointed limbs, +Such also is the intelligence of each man; for it is The nature +of limbs (organization) which thinketh in men, Both in one and +in all; for the highest degree of organization gives the +highest degree of thought."[11] + + +Here it will be observed that there is virtual agreement between +the translators except as to the last clause, but that clause is +most essential. The Greek phrase is <gr to gar pleon esti nohma>. +Ritter, it will be observed, renders this, "for thought is the +fulness." Lewes paraphrases it, "for the highest degree of +organization gives the highest degree of thought." The difference +is intentional, since Lewes himself criticises the translation of +Ritter. Ritter's translation is certainly the more literal, but +the fact that such diversity is possible suggests one of the +chief elements of uncertainty that hamper our interpretation of +the thought of antiquity. Unfortunately, the mind of the +commentator has usually been directed towards such subtleties, +rather than towards the expression of precise knowledge. Hence it +is that the philosophers of Greece are usually thought of as mere +dreamers, and that their true status as scientific discoverers is +so often overlooked. With these intangibilities we have no +present concern beyond this bare mention; for us it suffices to +gain as clear an idea as we may of the really scientific +conceptions of these thinkers, leaving the subtleties of their +deductive reasoning for the most part untouched. + + +EMPEDOCLES + +The latest of the important pre-Socratic philosophers of the +Italic school was Empedocles, who was born about 494 B.C. and +lived to the age of sixty. These dates make Empedocles strictly +contemporary with Anaxagoras, a fact which we shall do well to +bear in mind when we come to consider the latter's philosophy in +the succeeding chapter. Like Pythagoras, Empedocles is an +imposing figure. Indeed, there is much of similarity between the +personalities, as between the doctrines, of the two men. +Empedocles, like Pythagoras, was a physician; like him also he +was the founder of a cult. As statesman, prophet, physicist, +physician, reformer, and poet he showed a versatility that, +coupled with profundity, marks the highest genius. In point of +versatility we shall perhaps hardly find his equal at a later +day--unless, indeed, an exception be made of Eratosthenes. The +myths that have grown about the name of Empedocles show that he +was a remarkable personality. He is said to have been an +awe-inspiring figure, clothing himself in Oriental splendor and +moving among mankind as a superior being. Tradition has it that +he threw himself into the crater of a volcano that his otherwise +unexplained disappearance might lead his disciples to believe +that he had been miraculously translated; but tradition goes on +to say that one of the brazen slippers of the philosopher was +thrown up by the volcano, thus revealing his subterfuge. Another +tradition of far more credible aspect asserts that Empedocles +retreated from Italy, returning to the home of his fathers in +Peloponnesus to die there obscurely. It seems odd that the facts +regarding the death of so great a man, at so comparatively late a +period, should be obscure; but this, perhaps, is in keeping with +the personality of the man himself. His disciples would hesitate +to ascribe a merely natural death to so inspired a prophet. + +Empedocles appears to have been at once an observer and a +dreamer. He is credited with noting that the pressure of air will +sustain the weight of water in an inverted tube; with divining, +without the possibility of proof, that light has actual motion in +space; and with asserting that centrifugal motion must keep the +heavens from falling. He is credited with a great sanitary feat +in the draining of a marsh, and his knowledge of medicine was +held to be supernatural. Fortunately, some fragments of the +writings of Empedocles have come down to us, enabling us to judge +at first hand as to part of his doctrines; while still more is +known through the references made to him by Plato, Aristotle, and +other commentators. Empedocles was a poet whose verses stood the +test of criticism. In this regard he is in a like position with +Parmenides; but in neither case are the preserved fragments +sufficient to enable us fully to estimate their author's +scientific attainments. Philosophical writings are obscure enough +at the best, and they perforce become doubly so when expressed in +verse. Yet there are certain passages of Empedocles that are +unequivocal and full of interest. Perhaps the most important +conception which the works of Empedocles reveal to us is the +denial of anthropomorphism as applied to deity. We have seen how +early the anthropomorphic conception was developed and how +closely it was all along clung to; to shake the mind free from it +then was a remarkable feat, in accomplishing which Empedocles +took a long step in the direction of rationalism. His conception +is paralleled by that of another physician, Alcmaeon, of Proton, +who contended that man's ideas of the gods amounted to mere +suppositions at the very most. A rationalistic or sceptical +tendency has been the accompaniment of medical training in all +ages. + +The words in which Empedocles expresses his conception of deity +have been preserved and are well worth quoting: "It is not +impossible," he says, "to draw near (to god) even with the eyes +or to take hold of him with our hands, which in truth is the best +highway of persuasion in the mind of man; for he has no human +head fitted to a body, nor do two shoots branch out from the +trunk, nor has he feet, nor swift legs, nor hairy parts, but he +is sacred and ineffable mind alone, darting through the whole +world with swift thoughts."[8] + +How far Empedocles carried his denial of anthropomorphism is +illustrated by a reference of Aristotle, who asserts "that +Empedocles regards god as most lacking in the power of +perception; for he alone does not know one of the elements, +Strife (hence), of perishable things." It is difficult to avoid +the feeling that Empedocles here approaches the modern +philosophical conception that God, however postulated as +immutable, must also be postulated as unconscious, since +intelligence, as we know it, is dependent upon the transmutations +of matter. But to urge this thought would be to yield to that +philosophizing tendency which has been the bane of interpretation +as applied to the ancient thinkers. + +Considering for a moment the more tangible accomplishments of +Empedocles, we find it alleged that one of his "miracles" +consisted of the preservation of a dead body without putrefaction +for some weeks after death. We may assume from this that he had +gained in some way a knowledge of embalming. As he was +notoriously fond of experiment, and as the body in question +(assuming for the moment the authenticity of the legend) must +have been preserved without disfigurement, it is conceivable even +that he had hit upon the idea of injecting the arteries. This, of +course, is pure conjecture; yet it finds a certain warrant, both +in the fact that the words of Pythagoras lead us to believe that +the arteries were known and studied, and in the fact that +Empedocles' own words reveal him also as a student of the +vascular system. Thus Plutarch cites Empedocles as believing +"that the ruling part is not in the head or in the breast, but in +the blood; wherefore in whatever part of the body the more of +this is spread in that part men excel."[13] And Empedocles' own +words, as preserved by Stobaeus, assert "(the heart) lies in seas +of blood which dart in opposite directions, and there most of all +intelligence centres for men; for blood about the heart is +intelligence in the case of man." All this implies a really +remarkable appreciation of the dependence of vital activities +upon the blood. + +This correct physiological conception, however, was by no means +the most remarkable of the ideas to which Empedoeles was led by +his anatomical studies. His greatest accomplishment was to have +conceived and clearly expressed an idea which the modern +evolutionist connotes when he speaks of homologous parts--an idea +which found a famous modern expositor in Goethe, as we shall see +when we come to deal with eighteenth-century science. Empedocles +expresses the idea in these words: "Hair, and leaves, and thick +feathers of birds, are the same thing in origin, and reptile +scales too on strong limbs. But on hedgehogs sharp-pointed hair +bristles on their backs."[14] That the idea of transmutation of +parts, as well as of mere homology, was in mind is evidenced by a +very remarkable sentence in which Aristotle asserts, "Empedocles +says that fingernails rise from sinew from hardening." Nor is +this quite all, for surely we find the germ of the Lamarckian +conception of evolution through the transmission of acquired +characters in the assertion that "many characteristics appear in +animals because it happened to be thus in their birth, as that +they have such a spine because they happen to be descended from +one that bent itself backward."[15] Aristotle, in quoting this +remark, asserts, with the dogmatism which characterizes the +philosophical commentators of every age, that "Empedocles is +wrong," in making this assertion; but Lamarck, who lived +twenty-three hundred years after Empedocles, is famous in the +history of the doctrine of evolution for elaborating this very +idea. + +It is fair to add, however, that the dreamings of Empedocles +regarding the origin of living organisms led him to some +conceptions that were much less luminous. On occasion, Empedocles +the poet got the better of Empedocles the scientist, and we are +presented with a conception of creation as grotesque as that +which delighted the readers of Paradise Lost at a later day. +Empedocles assures us that "many heads grow up without necks, and +arms were wandering about, necks bereft of shoulders, and eyes +roamed about alone with no foreheads."[16] This chaotic +condition, so the poet dreamed, led to the union of many +incongruous parts, producing "creatures with double faces, +offspring of oxen with human faces, and children of men with oxen +heads." But out of this chaos came, finally, we are led to infer, +a harmonious aggregation of parts, producing ultimately the +perfected organisms that we see. Unfortunately the preserved +portions of the writings of Empedocles do not enlighten us as to +the precise way in which final evolution was supposed to be +effected; although the idea of endless experimentation until +natural selection resulted in survival of the fittest seems not +far afield from certain of the poetical assertions. Thus: "As +divinity was mingled yet more with divinity, these things (the +various members) kept coming together in whatever way each might +chance." Again: "At one time all the limbs which form the body +united into one by love grew vigorously in the prime of life; but +yet at another time, separated by evil Strife, they wander each +in different directions along the breakers of the sea of life. +Just so is it with plants, and with fishes dwelling in watery +halls, and beasts whose lair is in the mountains, and birds borne +on wings."[17] + +All this is poetry rather than science, yet such imaginings could +come only to one who was groping towards what we moderns should +term an evolutionary conception of the origins of organic life; +and however grotesque some of these expressions may appear, it +must be admitted that the morphological ideas of Empedocles, as +above quoted, give the Sicilian philosopher a secure place among +the anticipators of the modern evolutionist. + + + +VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + +We have travelled rather far in our study of Greek science, and +yet we have not until now come to Greece itself. And even now, +the men whose names we are to consider were, for the most part, +born in out- lying portions of the empire; they differed from the +others we have considered only in the fact that they were drawn +presently to the capital. The change is due to a most interesting +sequence of historical events. In the day when Thales and his +immediate successors taught in Miletus, when the great men of the +Italic school were in their prime, there was no single undisputed +Centre of Greek influence. The Greeks were a disorganized company +of petty nations, welded together chiefly by unity of speech; but +now, early in the fifth century B.C., occurred that famous attack +upon the Western world by the Persians under Darius and his son +and successor Xerxes. A few months of battling determined the +fate of the Western world. The Orientals were hurled back; the +glorious memories of Marathon, Salamis, and Plataea stimulated +the patriotism and enthusiasm of all children of the Greek race. +The Greeks, for the first time, occupied the centre of the +historical stage; for the brief interval of about half a century +the different Grecian principalities lived together in relative +harmony. One city was recognized as the metropolis of the loosely +bound empire; one city became the home of culture and the Mecca +towards which all eyes turned; that city, of course, was Athens. +For a brief time all roads led to Athens, as, at a later date, +they all led to Rome. The waterways which alone bound the widely +scattered parts of Hellas into a united whole led out from Athens +and back to Athens, as the spokes of a wheel to its hub. Athens +was the commercial centre, and, largely for that reason, it +became the centre of culture and intellectual influence also. The +wise men from the colonies visited the metropolis, and the wise +Athenians went out to the colonies. Whoever aspired to become a +leader in politics, in art, in literature, or in philosophy, made +his way to the capital, and so, with almost bewildering +suddenness, there blossomed the civilization of the age of +Pericles; the civilization which produced aeschylus, Sophocles, +Euripides, Herodotus, and Thucydides; the civilization which made +possible the building of the Parthenon. + + +ANAXAGORAS + +Sometime during the early part of this golden age there came to +Athens a middle-aged man from Clazomenae, who, from our present +stand-point, was a more interesting personality than perhaps any +other in the great galaxy of remarkable men assembled there. The +name of this new-comer was Anaxagoras. It was said in after-time, +we know not with what degree of truth, that he had been a pupil +of Anaximenes. If so, he was a pupil who departed far from the +teachings of his master. What we know for certain is that +Anaxagoras was a truly original thinker, and that he became a +close friend--in a sense the teacher--of Pericles and of +Euripides. Just how long he remained at Athens is not certain; +but the time came when he had made himself in some way +objectionable to the Athenian populace through his teachings. +Filled with the spirit of the investigator, he could not accept +the current conceptions as to the gods. He was a sceptic, an +innovator. Such men are never welcome; they are the chief factors +in the progress of thought, but they must look always to +posterity for recognition of their worth; from their +contemporaries they receive, not thanks, but persecution. +Sometimes this persecution takes one form, sometimes another; to +the credit of the Greeks be it said, that with them it usually +led to nothing more severe than banishment. In the case of +Anaxagoras, it is alleged that the sentence pronounced was death; +but that, thanks to the influence of Pericles, this sentence was +commuted to banishment. In any event, the aged philosopher was +sent away from the city of his adoption. He retired to Lampsacus. +"It is not I that have lost the Athenians," he said; "it is the +Athenians that have lost me." + +The exact position which Anaxagoras had among his contemporaries, +and his exact place in the development of philosophy, have always +been somewhat in dispute. It is not known, of a certainty, that +he even held an open school at Athens. Ritter thinks it doubtful +that he did. It was his fate to be misunderstood, or +underestimated, by Aristotle; that in itself would have sufficed +greatly to dim his fame--might, indeed, have led to his almost +entire neglect had he not been a truly remarkable thinker. With +most of the questions that have exercised the commentators we +have but scant concern. Following Aristotle, most historians of +philosophy have been metaphysicians; they have concerned +themselves far less with what the ancient thinkers really knew +than with what they thought. A chance using of a verbal quibble, +an esoteric phrase, the expression of a vague mysticism--these +would suffice to call forth reams of exposition. It has been the +favorite pastime of historians to weave their own anachronistic +theories upon the scanty woof of the half- remembered thoughts of +the ancient philosophers. To make such cloth of the imagination +as this is an alluring pastime, but one that must not divert us +here. Our point of view reverses that of the philosophers. We are +chiefly concerned, not with some vague saying of Anaxagoras, but +with what he really knew regarding the phenomena of nature; with +what he observed, and with the comprehensible deductions that he +derived from his observations. In attempting to answer these +inquiries, we are obliged, in part, to take our evidence at +second-hand; but, fortunately, some fragments of writings of +Anaxagoras have come down to us. We are told that he wrote only a +single book. It was said even (by Diogenes) that he was the first +man that ever wrote a work in prose. The latter statement would +not bear too close an examination, yet it is true that no +extensive prose compositions of an earlier day than this have +been preserved, though numerous others are known by their +fragments. Herodotus, "the father of prose," was a slightly +younger contemporary of the Clazomenaean philosopher; not +unlikely the two men may have met at Athens. + +Notwithstanding the loss of the greater part of the writings of +Anaxagoras, however, a tolerably precise account of his +scientific doctrines is accessible. Diogenes Laertius expresses +some of them in very clear and precise terms. We have already +pointed out the uncertainty that attaches to such evidence as +this, but it is as valid for Anaxagoras as for another. If we +reject such evidence, we shall often have almost nothing left; in +accepting it we may at least feel certain that we are viewing the +thinker as his contemporaries and immediate successors viewed +him. Following Diogenes, then, we shall find some remarkable +scientific opinions ascribed to Anaxagoras. "He asserted," we are +told, "that the sun was a mass of burning iron, greater than +Peloponnesus, and that the moon contained houses and also hills +and ravines." In corroboration of this, Plato represents him as +having conjectured the right explanation of the moon's light, and +of the solar and lunar eclipses. He had other astronomical +theories that were more fanciful; thus "he said that the stars +originally moved about in irregular confusion, so that at first +the pole-star, which is continually visible, always appeared in +the zenith, but that afterwards it acquired a certain +declination, and that the Milky Way was a reflection of the light +of the sun when the stars did not appear. The comets he +considered to be a concourse of planets emitting rays, and the +shooting- stars he thought were sparks, as it were, leaping from +the firmament." + +Much of this is far enough from the truth, as we now know it, yet +all of it shows an earnest endeavor to explain the observed +phenomena of the heavens on rational principles. To have +predicated the sun as a great molten mass of iron was indeed a +wonderful anticipation of the results of the modern spectroscope. +Nor can it be said that this hypothesis of Anaxagoras was a +purely visionary guess. It was in all probability a scientific +deduction from the observed character of meteoric stones. +Reference has already been made to the alleged prediction of the +fall of the famous meteor at aegespotomi by Anaxagoras. The +assertion that he actually predicted this fall in any proper +sense of the word would be obviously absurd. Yet the fact that +his name is associated with it suggests that he had studied +similar meteorites, or else that he studied this particular one, +since it is not quite clear whether it was before or after this +fall that he made the famous assertion that space is full of +falling stones. We should stretch the probabilities were we to +assert that Anaxagoras knew that shooting-stars and meteors were +the same, yet there is an interesting suggestiveness in his +likening the shooting-stars to sparks leaping from the firmament, +taken in connection with his observation on meteorites. Be this +as it may, the fact that something which falls from heaven as a +blazing light turns out to be an iron-like mass may very well +have suggested to the most rational of thinkers that the great +blazing light called the sun has the same composition. This idea +grasped, it was a not unnatural extension to conceive the other +heavenly bodies as having the same composition. + +This led to a truly startling thought. Since the heavenly bodies +are of the same composition as the earth, and since they are +observed to be whirling about the earth in space, may we not +suppose that they were once a part of the earth itself, and that +they have been thrown off by the force of a whirling motion? Such +was the conclusion which Anaxagoras reached; such his explanation +of the origin of the heavenly bodies. It was a marvellous guess. +Deduct from it all that recent science has shown to be untrue; +bear in mind that the stars are suns, compared with which the +earth is a mere speck of dust; recall that the sun is parent, not +daughter, of the earth, and despite all these deductions, the +cosmogonic guess of Anaxagoras remains, as it seems to us, one of +the most marvellous feats of human intelligence. It was the first +explanation of the cosmic bodies that could be called, in any +sense, an anticipation of what the science of our own day accepts +as a true explanation of cosmic origins. Moreover, let us urge +again that this was no mere accidental flight of the imagination; +it was a scientific induction based on the only data available; +perhaps it is not too much to say that it was the only scientific +induction which these data would fairly sustain. Of course it is +not for a moment to be inferred that Anaxagoras understood, in +the modern sense, the character of that whirling force which we +call centrifugal. About two thousand years were yet to elapse +before that force was explained as elementary inertia; and even +that explanation, let us not forget, merely sufficed to push back +the barriers of mystery by one other stage; for even in our day +inertia is a statement of fact rather than an explanation. + +But however little Anaxagoras could explain the centrifugal force +on mechanical principles, the practical powers of that force were +sufficiently open to his observation. The mere experiment of +throwing a stone from a sling would, to an observing mind, be +full of suggestiveness. It would be obvious that by whirling the +sling about, the stone which it held would be sustained in its +circling path about the hand in seeming defiance of the earth's +pull, and after the stone had left the sling, it could fly away +from the earth to a distance which the most casual observation +would prove to be proportionate to the speed of its flight. +Extremely rapid motion, then, might project bodies from the +earth's surface off into space; a sufficiently rapid whirl would +keep them there. Anaxagoras conceived that this was precisely +what had occurred. His imagination even carried him a step +farther--to a conception of a slackening of speed, through which +the heavenly bodies would lose their centrifugal force, and, +responding to the perpetual pull of gravitation, would fall back +to the earth, just as the great stone at aegespotomi had been +observed to do. + +Here we would seem to have a clear conception of the idea of +universal gravitation, and Anaxagoras stands before us as the +anticipator of Newton. Were it not for one scientific maxim, we +might exalt the old Greek above the greatest of modern natural +philosophers; but that maxim bids us pause. It is phrased thus, +"He discovers who proves." Anaxagoras could not prove; his +argument was at best suggestive, not demonstrative. He did not +even know the laws which govern falling bodies; much less could +he apply such laws, even had he known them, to sidereal bodies at +whose size and distance he could only guess in the vaguest terms. +Still his cosmogonic speculation remains as perhaps the most +remarkable one of antiquity. How widely his speculation found +currency among his immediate successors is instanced in a passage +from Plato, where Socrates is represented as scornfully answering +a calumniator in these terms: "He asserts that I say the sun is a +stone and the moon an earth. Do you think of accusing Anaxagoras, +Miletas, and have you so low an opinion of these men, and think +them so unskilled in laws, as not to know that the books of +Anaxagoras the Clazomenaean are full of these doctrines. And +forsooth the young men are learning these matters from me which +sometimes they can buy from the orchestra for a drachma, at the +most, and laugh at Socrates if he pretends they are +his-particularly seeing they are so strange." + +The element of error contained in these cosmogonic speculations +of Anaxagoras has led critics to do them something less than +justice. But there is one other astronomical speculation for +which the Clazomenaean philosopher has received full credit. It +is generally admitted that it was he who first found out the +explanation of the phases of the moon; a knowledge that that body +shines only by reflected light, and that its visible forms, +waxing and waning month by month from crescent to disk and from +disk to crescent, merely represent our shifting view of its +sun-illumined face. It is difficult to put ourselves in the place +of the ancient observer and realize how little the appearances +suggest the actual fact. That a body of the same structure as the +earth should shine with the radiance of the moon merely because +sunlight is reflected from it, is in itself a supposition +seemingly contradicted by ordinary experience. It required the +mind of a philosopher, sustained, perhaps, by some experimental +observations, to conceive the idea that what seems so obviously +bright may be in reality dark. The germ of the conception of what +the philosopher speaks of as the noumena, or actualities, back of +phenomena or appearances, had perhaps this crude beginning. +Anaxagoras could surely point to the moon in support of his +seeming paradox that snow, being really composed of water, which +is dark, is in reality black and not white--a contention to which +we shall refer more at length in a moment. + +But there is yet another striking thought connected with this new +explanation of the phases of the moon. The explanation implies +not merely the reflection of light by a dark body, but by a dark +body of a particular form. Granted that reflections are in +question, no body but a spherical one could give an appearance +which the moon presents. The moon, then, is not merely a mass of +earth, it is a spherical mass of earth. Here there were no flaws +in the reasoning of Anaxagoras. By scientific induction he passed +from observation to explanation. A new and most important element +was added to the science of astronomy. + +Looking back from the latter-day stand-point, it would seem as if +the mind of the philosopher must have taken one other step: the +mind that had conceived sun, moon, stars, and earth to be of one +substance might naturally, we should think, have reached out to +the further induction that, since the moon is a sphere, the other +cosmic bodies, including the earth, must be spheres also. But +generalizer as he was, Anaxagoras was too rigidly scientific a +thinker to make this assumption. The data at his command did not, +as he analyzed them, seem to point to this conclusion. We have +seen that Pythagoras probably, and Parmenides surely, out there +in Italy had conceived the idea of the earth's rotundity, but the +Pythagorean doctrines were not rapidly taken up in the mother- +country, and Parmenides, it must be recalled, was a strict +contemporary of Anaxagoras himself. It is no reproach, therefore, +to the Clazomenaean philosopher that he should have held to the +old idea that the earth is flat, or at most a convex disk--the +latter being the Babylonian conception which probably dominated +that Milesian school to which Anaxagoras harked back. + +Anaxagoras may never have seen an eclipse of the moon, and even +if he had he might have reflected that, from certain directions, +a disk may throw precisely the same shadow as a sphere. Moreover, +in reference to the shadow cast by the earth, there was, so +Anaxagoras believed, an observation open to him nightly which, we +may well suppose, was not without influence in suggesting to his +mind the probable shape of the earth. The Milky Way, which +doubtless had puzzled astronomers from the beginnings of history +and which was to continue to puzzle them for many centuries after +the day of Anaxagoras, was explained by the Clazomenaean +philosopher on a theory obviously suggested by the theory of the +moon's phases. Since the earth- like moon shines by reflected +light at night, and since the stars seem obviously brighter on +dark nights, Anaxagoras was but following up a perfectly logical +induction when he propounded the theory that the stars in the +Milky Way seem more numerous and brighter than those of any other +part of the heavens, merely because the Milky Way marks the +shadow of the earth. Of course the inference was wrong, so far as +the shadow of the earth is concerned; yet it contained a part +truth, the force of which was never fully recognized until the +time of Galileo. This consists in the assertion that the +brightness of the Milky Way is merely due to the glow of many +stars. The shadow- theory of Anaxagoras would naturally cease to +have validity so soon as the sphericity of the earth was proved, +and with it, seemingly, fell for the time the companion theory +that the Milky Way is made up of a multitude of stars. + +It has been said by a modern critic[1] that the shadow-theory was +childish in that it failed to note that the Milky Way does not +follow the course of the ecliptic. But this criticism only holds +good so long as we reflect on the true character of the earth as +a symmetrical body poised in space. It is quite possible to +conceive a body occupying the position of the earth with +reference to the sun which would cast a shadow having such a +tenuous form as the Milky Way presents. Such a body obviously +would not be a globe, but a long-drawn-out, attenuated figure. +There is, to be sure, no direct evidence preserved to show that +Anaxagoras conceived the world to present such a figure as this, +but what we know of that philosopher's close-reasoning, logical +mind gives some warrant to the assumption--gratuitous though in a +sense it be-- that the author of the theory of the moon's phases +had not failed to ask himself what must be the form of that +terrestrial body which could cast the tenuous shadow of the Milky +Way. Moreover, we must recall that the habitable earth, as known +to the Greeks of that day, was a relatively narrow band of +territory, stretching far to the east and to the west. + + +Anaxagoras as Meteorologist + +The man who had studied the meteorite of aegospotami, and been +put by it on the track of such remarkable inductions, was, +naturally, not oblivious to the other phenomena of the +atmosphere. Indeed, such a mind as that of Anaxagoras was sure to +investigate all manner of natural phenomena, and almost equally +sure to throw new light on any subject that it investigated. +Hence it is not surprising to find Anaxagoras credited with +explaining the winds as due to the rarefactions of the atmosphere +produced by the sun. This explanation gives Anaxagoras full right +to be called "the father of meteorology," a title which, it may +be, no one has thought of applying to him, chiefly because the +science of meteorology did not make its real beginnings until +some twenty-four hundred years after the death of its first great +votary. Not content with explaining the winds, this prototype of +Franklin turned his attention even to the tipper atmosphere. +"Thunder," he is reputed to have said, "was produced by the +collision of the clouds, and lightning by the rubbing together of +the clouds." We dare not go so far as to suggest that this +implies an association in the mind of Anaxagoras between the +friction of the clouds and the observed electrical effects +generated by the friction of such a substance as amber. To make +such a suggestion doubtless would be to fall victim to the old +familiar propensity to read into Homer things that Homer never +knew. Yet the significant fact remains that Anaxagoras ascribed +to thunder and to lightning their true position as strictly +natural phenomena. For him it was no god that menaced humanity +with thundering voice and the flash of his divine fires from the +clouds. Little wonder that the thinker whose science carried him +to such scepticism as this should have felt the wrath of the +superstitious Athenians. + + +Biological Speculations + +Passing from the phenomena of the air to those of the earth +itself, we learn that Anaxagoras explained an earthquake as being +produced by the returning of air into the earth. We cannot be +sure as to the exact meaning here, though the idea that gases are +imprisoned in the substance of the earth seems not far afield. +But a far more remarkable insight than this would imply was shown +by Anaxagoras when he asserted that a certain amount of air is +contained in water, and that fishes breathe this air. The passage +of Aristotle in which this opinion is ascribed to Anaxagoras is +of sufficient interest to be quoted at length: + +"Democritus, of Abdera," says Aristotle, "and some others, that +have spoken concerning respiration, have determined nothing +concerning other animals, but seem to have supposed that all +animals respire. But Anaxagoras and Diogenes (Apolloniates), who +say that all animals respire, have also endeavored to explain how +fishes, and all those animals that have a hard, rough shell, such +as oysters, mussels, etc., respire. And Anaxagoras, indeed, says +that fishes, when they emit water through their gills, attract +air from the mouth to the vacuum in the viscera from the water +which surrounds the mouth; as if air was inherent in the +water."[2] + +It should be recalled that of the three philosophers thus +mentioned as contending that all animals respire, Anaxagoras was +the elder; he, therefore, was presumably the originator of the +idea. It will be observed, too, that Anaxagoras alone is held +responsible for the idea that fishes respire air through their +gills, "attracting" it from the water. This certainly was one of +the shrewdest physiological guesses of any age, if it be regarded +as a mere guess. With greater justice we might refer to it as a +profound deduction from the principle of the uniformity of +nature. + +In making such a deduction, Anaxagoras was far in advance of his +time as illustrated by the fact that Aristotle makes the citation +we have just quoted merely to add that "such things are +impossible," and to refute these "impossible" ideas by means of +metaphysical reasonings that seemed demonstrative not merely to +himself, but to many generations of his followers. + +We are told that Anaxagoras alleged that all animals were +originally generated out of moisture, heat, and earth particles. +Just what opinion he held concerning man's development we are not +informed. Yet there is one of his phrases which +suggests--without, perhaps, quite proving--that he was an +evolutionist. This phrase asserts, with insight that is fairly +startling, that man is the most intelligent of animals because he +has hands. The man who could make that assertion must, it would +seem, have had in mind the idea of the development of +intelligence through the use of hands-- an idea the full force of +which was not evident to subsequent generations of thinkers until +the time of Darwin. + + +Physical Speculations + +Anaxagoras is cited by Aristotle as believing that "plants are +animals and feel pleasure and pain, inferring this because they +shed their leaves and let them grow again." The idea is fanciful, +yet it suggests again a truly philosophical conception of the +unity of nature. The man who could conceive that idea was but +little hampered by traditional conceptions. He was exercising a +rare combination of the rigidly scientific spirit with the +poetical imagination. He who possesses these gifts is sure not to +stop in his questionings of nature until he has found some +thinkable explanation of the character of matter itself. +Anaxagoras found such an explanation, and, as good luck would +have it, that explanation has been preserved. Let us examine his +reasoning in some detail. We have already referred to the claim +alleged to have been made by Anaxagoras that snow is not really +white, but black. The philosopher explained his paradox, we are +told, by asserting that snow is really water, and that water is +dark, when viewed under proper conditions--as at the bottom of a +well. That idea contains the germ of the Clazomenaean +philosopher's conception of the nature of matter. Indeed, it is +not unlikely that this theory of matter grew out of his +observation of the changing forms of water. He seems clearly to +have grasped the idea that snow on the one hand, and vapor on the +other, are of the same intimate substance as the water from which +they are derived and into which they may be again transformed. +The fact that steam and snow can be changed back into water, and +by simple manipulation cannot be changed into any other +substance, finds, as we now believe, its true explanation in the +fact that the molecular structure, as we phrase it--that is to +say, the ultimate particle of which water is composed, is not +changed, and this is precisely the explanation which Anaxagoras +gave of the same phenomena. For him the unit particle of water +constituted an elementary body, uncreated, unchangeable, +indestructible. This particle, in association with like +particles, constitutes the substance which we call water. The +same particle in association with particles unlike itself, might +produce totally different substances--as, for example, when water +is taken up by the roots of a plant and becomes, seemingly, a +part of the substance of the plant. But whatever the changed +association, so Anaxagoras reasoned, the ultimate particle of +water remains a particle of water still. And what was true of +water was true also, so he conceived, of every other substance. +Gold, silver, iron, earth, and the various vegetables and animal +tissues--in short, each and every one of all the different +substances with which experience makes us familiar, is made up of +unit particles which maintain their integrity in whatever +combination they may be associated. This implies, obviously, a +multitude of primordial particles, each one having an +individuality of its own; each one, like the particle of water +already cited, uncreated, unchangeable, and indestructible. + +Fortunately, we have the philosopher's own words to guide us as +to his speculations here. The fragments of his writings that have +come down to us (chiefly through the quotations of Simplicius) +deal almost exclusively with these ultimate conceptions of his +imagination. In ascribing to him, then, this conception of +diverse, uncreated, primordial elements, which can never be +changed, but can only be mixed together to form substances of the +material world, we are not reading back post-Daltonian knowledge +into the system of Anaxagoras. Here are his words: "The Greeks do +not rightly use the terms 'coming into being' and 'perishing.' +For nothing comes into being, nor, yet, does anything perish; but +there is mixture and separation of things that are. So they would +do right in calling 'coming into being' 'mixture' and 'perishing' +'separation.' For how could hair come from what is not hair? Or +flesh from what is not flesh?" + +Elsewhere he tells us that (at one stage of the world's +development) "the dense, the moist, the cold, the dark, collected +there where now is earth; the rare, the warm, the dry, the +bright, departed towards the further part of the aether. The +earth is condensed out of these things that are separated, for +water is separated from the clouds, and earth from the water; and +from the earth stones are condensed by the cold, and these are +separated farther from the water." Here again the influence of +heat and cold in determining physical qualities is kept +pre-eminently in mind. The dense, the moist, the cold, the dark +are contrasted with the rare, the warm, the dry, and bright; and +the formation of stones is spoken of as a specific condensation +due to the influence of cold. Here, then, we have nearly all the +elements of the Daltonian theory of atoms on the one hand, and +the nebular hypothesis of Laplace on the other. But this is not +quite all. In addition to such diverse elementary particles as +those of gold, water, and the rest, Anaxagoras conceived a +species of particles differing from all the others, not merely as +they differ from one another, but constituting a class by +themselves; particles infinitely smaller than the others; +particles that are described as infinite, self-powerful, mixed +with nothing, but existing alone. That is to say (interpreting +the theory in the only way that seems plausible), these most +minute particles do not mix with the other primordial particles +to form material substances in the same way in which these mixed +with one another. But, on the other hand, these "infinite, +self-powerful, and unmixed" particles commingle everywhere and in +every substance whatever with the mixed particles that go to make +up the substances. + +There is a distinction here, it will be observed, which at once +suggests the modern distinction between physical processes and +chemical processes, or, putting it otherwise, between molecular +processes and atomic processes; but the reader must be guarded +against supposing that Anaxagoras had any such thought as this in +mind. His ultimate mixable particles can be compared only with +the Daltonian atom, not with the molecule of the modern +physicist, and his "infinite, self- powerful, and unmixable" +particles are not comparable with anything but the ether of the +modern physicist, with which hypothetical substance they have +many points of resemblance. But the "infinite, self- powerful, +and unmixed" particles constituting thus an ether-like plenum +which permeates all material structures, have also, in the mind +of Anaxagoras, a function which carries them perhaps a stage +beyond the province of the modern ether. For these "infinite, +self powerful, and unmixed" particles are imbued with, and, +indeed, themselves constitute, what Anaxagoras terms nous, a word +which the modern translator has usually paraphrased as "mind." +Neither that word nor any other available one probably conveys an +accurate idea of what Anaxagoras meant to imply by the word nous. +For him the word meant not merely "mind" in the sense of +receptive and comprehending intelligence, but directive and +creative intelligence as well. Again let Anaxagoras speak for +himself: "Other things include a portion of everything, but nous +is infinite, and self-powerful, and mixed with nothing, but it +exists alone, itself by itself. For if it were not by itself, but +were mixed with anything else, it would include parts of all +things, if it were mixed with anything; for a portion of +everything exists in every thing, as has been said by me before, +and things mingled with it would prevent it from having power +over anything in the same way that it does now that it is alone +by itself. For it is the most rarefied of all things and the +purest, and it has all knowledge in regard to everything and the +greatest power; over all that has life, both greater and less, +nous rules. And nous ruled the rotation of the whole, so that it +set it in rotation in the beginning. First it began the rotation +from a small beginning, then more and more was included in the +motion, and yet more will be included. Both the mixed and the +separated and distinct, all things nous recognized. And whatever +things were to be, and whatever things were, as many as are now, +and whatever things shall be, all these nous arranged in order; +and it arranged that rotation, according to which now rotate +stars and sun and moon and air and aether, now that they are +separated. Rotation itself caused the separation, and the dense +is separated from the rare, the warm from the cold, the bright +from the dark, the dry from the moist. And when nous began to set +things in motion, there was separation from everything that was +in motion, all this was made distinct. The rotation of the things +that were moved and made distinct caused them to be yet more +distinct."[3] + +Nous, then, as Anaxagoras conceives it, is "the most rarefied of +all things, and the purest, and it has knowledge in regard to +everything and the greatest power; over all that has life, both +greater and less, it rules." But these are postulants of +omnipresence and omniscience. In other words, nous is nothing +less than the omnipotent artificer of the material universe. It +lacks nothing of the power of deity, save only that we are not +assured that it created the primordial particles. The creation of +these particles was a conception that for Anaxagoras, as for the +modern Spencer, lay beyond the range of imagination. Nous is the +artificer, working with "uncreated" particles. Back of nous and +the particles lies, for an Anaxagoras as for a Spencer, the +Unknowable. But nous itself is the equivalent of that universal +energy of motion which science recognizes as operating between +the particles of matter, and which the theologist personifies as +Deity. It is Pantheistic deity as Anaxagoras conceives it; his +may be called the first scientific conception of a non- +anthropomorphic god. In elaborating this conception Anaxagoras +proved himself one of the most remarkable scientific dreamers of +antiquity. To have substituted for the Greek Pantheon of +anthropomorphic deities the conception of a non-anthropomorphic +immaterial and ethereal entity, of all things in the world "the +most rarefied and the purest," is to have performed a feat which, +considering the age and the environment in which it was +accomplished, staggers the imagination. As a strictly scientific +accomplishment the great thinker's conception of primordial +elements contained a germ of the truth which was to lie dormant +for 2200 years, but which then, as modified and vitalized by the +genius of Dalton, was to dominate the new chemical science of the +nineteenth century. If there are intimations that the primordial +element of Anaxagoras and of Dalton may turn out in the near +future to be itself a compound, there will still remain the yet +finer particles of the nous of Anaxagoras to baffle the most +subtle analysis of which to-day's science gives us any +pre-vision. All in all, then, the work of Anaxagoras must stand +as that of perhaps the most far-seeing scientific imagination of +pre-Socratic antiquity. + + +LEUCIPPUS AND DEMOCRITUS + +But we must not leave this alluring field of speculation as to +the nature of matter without referring to another scientific +guess, which soon followed that of Anaxagoras and was destined to +gain even wider fame, and which in modern times has been somewhat +unjustly held to eclipse the glory of the other achievement. We +mean, of course, the atomic theory of Leucippus and Democritus. +This theory reduced all matter to primordial elements, called +atoms <gr atoma> because they are by hypothesis incapable of +further division. These atoms, making up the entire material +universe, are in this theory conceived as qualitatively +identical, differing from one another only in size and perhaps in +shape. The union of different-sized atoms in endless combinations +produces the diverse substances with which our senses make us +familiar. + +Before we pass to a consideration of this alluring theory, and +particularly to a comparison of it with the theory of Anaxagoras, +we must catch a glimpse of the personality of the men to whom the +theory owes its origin. One of these, Leucippus, presents so +uncertain a figure as to be almost mythical. Indeed, it was long +questioned whether such a man had actually lived, or whether be +were not really an invention of his alleged disciple, Democritus. +Latterday scholarship, however, accepts him as a real personage, +though knowing scarcely more of him than that he was the author +of the famous theory with which his name was associated. It is +suggested that he was a wanderer, like most philosophers of his +time, and that later in life he came to Abdera, in Thrace, and +through this circumstance became the teacher of Democritus. This +fable answers as well as another. What we really know is that +Democritus himself, through whose writings and teachings the +atomic theory gained vogue, was born in Abdera, about the year +460 B.C.--that is to say, just about the time when his great +precursor, Anaxagoras, was migrating to Athens. Democritus, like +most others of the early Greek thinkers, lives in tradition as a +picturesque figure. It is vaguely reported that he travelled for +a time, perhaps in the East and in Egypt, and that then he +settled down to spend the remainder of his life in Abdera. +Whether or not he visited Athens in the course of his wanderings +we do not know. At Abdera he was revered as a sage, but his +influence upon the practical civilization of the time was not +marked. He was pre-eminently a dreamer and a writer. Like his +confreres of the epoch, he entered all fields of thought. He +wrote voluminously, but, unfortunately, his writings have, for +the most part, perished. The fables and traditions of a later day +asserted that Democritus had voluntarily put out his own eyes +that he might turn his thoughts inward with more concentration. +Doubtless this is fiction, yet, as usual with such fictions, it +contains a germ of truth; for we may well suppose that the +promulgator of the atomic theory was a man whose mind was +attracted by the subtleties of thought rather than by the +tangibilities of observation. Yet the term "laughing +philosopher," which seems to have been universally applied to +Democritus, suggests a mind not altogether withdrawn from the +world of practicalities. + +So much for Democritus the man. Let us return now to his theory +of atoms. This theory, it must be confessed, made no very great +impression upon his contemporaries. It found an expositor, a +little later, in the philosopher Epicurus, and later still the +poet Lucretius gave it popular expression. But it seemed scarcely +more than the dream of a philosopher or the vagary of a poet +until the day when modern science began to penetrate the +mysteries of matter. When, finally, the researches of Dalton and +his followers had placed the atomic theory on a surer footing as +the foundation of modern chemistry, the ideas of the old laughing +philosopher of Abdera, which all along had been half derisively +remembered, were recalled with a new interest. Now it appeared +that these ideas had curiously foreshadowed nineteenth-century +knowledge. It appeared that away back in the fifth century B.C. a +man had dreamed out a conception of the ultimate nature of matter +which had waited all these centuries for corroboration. And now +the historians of philosophy became more than anxious to do +justice to the memory of Democritus. + +It is possible that this effort at poetical restitution has +carried the enthusiast too far. There is, indeed, a curious +suggestiveness in the theory of Democritus; there is +philosophical allurement in his reduction of all matter to a +single element; it contains, it may be, not merely a germ of the +science of the nineteenth-century chemistry, but perhaps the +germs also of the yet undeveloped chemistry of the twentieth +century. Yet we dare suggest that in their enthusiasm for the +atomic theory of Democritus the historians of our generation have +done something less than justice to that philosopher's precursor, +Anaxagoras. And one suspects that the mere accident of a name has +been instrumental in producing this result. Democritus called his +primordial element an atom; Anaxagoras, too, conceived a +primordial element, but he called it merely a seed or thing; he +failed to christen it distinctively. Modern science adopted the +word atom and gave it universal vogue. It owed a debt of +gratitude to Democritus for supplying it the word, but it +somewhat overpaid the debt in too closely linking the new meaning +of the word with its old original one. For, let it be clearly +understood, the Daltonian atom is not precisely comparable with +the atom of Democritus. The atom, as Democritus conceived it, was +monistic; all atoms, according to this hypothesis, are of the +same substance; one atom differs from another merely in size and +shape, but not at all in quality. But the Daltonian hypothesis +conceived, and nearly all the experimental efforts of the +nineteenth century seemed to prove, that there are numerous +classes of atoms, each differing in its very essence from the +others. + +As the case stands to-day the chemist deals with seventy-odd +substances, which he calls elements. Each one of these substances +is, as he conceives it, made up of elementary atoms having a +unique personality, each differing in quality from all the +others. As far as experiment has thus far safely carried us, the +atom of gold is a primordial element which remains an atom of +gold and nothing else, no matter with what other atoms it is +associated. So, too, of the atom of silver, or zinc, or +sodium--in short, of each and every one of the seventy-odd +elements. There are, indeed, as we shall see, experiments that +suggest the dissolution of the atom--that suggest, in short, that +the Daltonian atom is misnamed, being a structure that may, under +certain conditions, be broken asunder. But these experiments +have, as yet, the warrant rather of philosophy than of pure +science, and to-day we demand that the philosophy of science +shall be the handmaid of experiment. + +When experiment shall have demonstrated that the Daltonian atom +is a compound, and that in truth there is but a single true atom, +which, combining with its fellows perhaps in varying numbers and +in different special relations, produces the Daltonian atoms, +then the philosophical theory of monism will have the +experimental warrant which to-day it lacks; then we shall be a +step nearer to the atom of Democritus in one direction, a step +farther away in the other. We shall be nearer, in that the +conception of Democritus was, in a sense, monistic; farther away, +in that all the atoms of Democritus, large and small alike, were +considered as permanently fixed in size. Democritus postulated +all his atoms as of the same substance, differing not at all in +quality; yet he was obliged to conceive that the varying size of +the atoms gave to them varying functions which amounted to +qualitative differences. He might claim for his largest atom the +same quality of substance as for his smallest, but so long as he +conceived that the large atoms, when adjusted together to form a +tangible substance, formed a substance different in quality from +the substance which the small atoms would make up when similarly +grouped, this concession amounts to the predication of difference +of quality between the atoms themselves. The entire question +reduces itself virtually to a quibble over the word quality, So +long as one atom conceived to be primordial and indivisible is +conceded to be of such a nature as necessarily to produce a +different impression on our senses, when grouped with its +fellows, from the impression produced by other atoms when +similarly grouped, such primordial atoms do differ among +themselves in precisely the same way for all practical purposes +as do the primordial elements of Anaxagoras. + +The monistic conception towards which twentieth- century +chemistry seems to be carrying us may perhaps show that all the +so-called atoms are compounded of a single element. All the true +atoms making up that element may then properly be said to have +the same quality, but none the less will it remain true that the +combinations of that element that go to make up the different +Daltonian atoms differ from one another in quality in precisely +the same sense in which such tangible substances as gold, and +oxygen, and mercury, and diamonds differ from one another. In the +last analysis of the monistic philosophy, there is but one +substance and one quality in the universe. In the widest view of +that philosophy, gold and oxygen and mercury and diamonds are one +substance, and, if you please, one quality. But such refinements +of analysis as this are for the transcendental philosopher, and +not for the scientist. Whatever the allurement of such reasoning, +we must for the purpose of science let words have a specific +meaning, nor must we let a mere word-jugglery blind us to the +evidence of facts. That was the rock on which Greek science +foundered; it is the rock which the modern helmsman sometimes +finds it difficult to avoid. And if we mistake not, this case of +the atom of Democritus is precisely a case in point. Because +Democritus said that his atoms did not differ in quality, the +modern philosopher has seen in his theory the essentials of +monism; has discovered in it not merely a forecast of the +chemistry of the nineteenth century, but a forecast of the +hypothetical chemistry of the future. And, on the other hand, +because Anaxagoras predicted a different quality for his +primordial elements, the philosopher of our day has discredited +the primordial element of Anaxagoras. + +Yet if our analysis does not lead us astray, the theory of +Democritus was not truly monistic; his indestructible atoms, +differing from one another in size and shape, utterly incapable +of being changed from the form which they had maintained from the +beginning, were in reality as truly and primordially different as +are the primordial elements of Anaxagoras. In other words, the +atom of Democritus is nothing less than the primordial seed of +Anaxagoras, a little more tangibly visualized and given a +distinctive name. Anaxagoras explicitly conceived his elements as +invisibly small, as infinite in number, and as made up of an +indefinite number of kinds--one for each distinctive substance in +the world. But precisely the same postulates are made of the atom +of Democritus. These also are invisibly small; these also are +infinite in number; these also are made up of an indefinite +number of kinds, corresponding with the observed difference of +substances in the world. "Primitive seeds," or "atoms," were +alike conceived to be primordial, un- changeable, and +indestructible. Wherein then lies the difference? We answer, +chiefly in a name; almost solely in the fact that Anaxagoras did +not attempt to postulate the physical properties of the elements +beyond stating that each has a distinctive personality, while +Democritus did attempt to postulate these properties. He, too, +admitted that each kind of element has its distinctive +personality, and he attempted to visualize and describe the +characteristics of the personality. + +Thus while Anaxagoras tells us nothing of his elements except +that they differ from one another, Democritus postulates a +difference in size, imagines some elements as heavier and some as +lighter, and conceives even that the elements may be provided +with projecting hooks, with the aid of which they link themselves +one with another. No one to-day takes these crude visualizings +seriously as to their details. The sole element of truth which +these dreamings contain, as distinguishing them from the +dreamings of Anaxagoras, is in the conception that the various +atoms differ in size and weight. Here, indeed, is a vague +fore-shadowing of that chemistry of form which began to come into +prominence towards the close of the nineteenth century. To have +forecast even dimly this newest phase of chemical knowledge, +across the abyss of centuries, is indeed a feat to put Democritus +in the front rank of thinkers. But this estimate should not blind +us to the fact that the pre-vision of Democritus was but a slight +elaboration of a theory which had its origin with another +thinker. The association between Anaxagoras and Democritus cannot +be directly traced, but it is an association which the historian +of ideas should never for a moment forget. If we are not to be +misled by mere word-jugglery, we shall recognize the founder of +the atomic theory of matter in Anaxagoras; its expositors along +slightly different lines in Leucippus and Democritus; its +re-discoverer of the nineteenth century in Dalton. All in all, +then, just as Anaxagoras preceded Democritus in time, so must he +take precedence over him also as an inductive thinker, who +carried the use of the scientific imagination to its farthest +reach. + +An analysis of the theories of the two men leads to somewhat the +same conclusion that might be reached from a comparison of their +lives. Anaxagoras was a sceptical, experimental scientist, gifted +also with the prophetic imagination. He reasoned always from the +particular to the general, after the manner of true induction, +and he scarcely took a step beyond the confines of secure +induction. True scientist that he was, he could content himself +with postulating different qualities for his elements, without +pretending to know how these qualities could be defined. His +elements were by hypothesis invisible, hence he would not attempt +to visualize them. Democritus, on the other hand, refused to +recognize this barrier. Where he could not know, he still did not +hesitate to guess. Just as he conceived his atom of a definite +form with a definite structure, even so he conceived that the +atmosphere about him was full of invisible spirits; he accepted +the current superstitions of his time. Like the average Greeks of +his day, he even believed in such omens as those furnished by +inspecting the entrails of a fowl. These chance bits of biography +are weather- vanes of the mind of Democritus. They tend to +substantiate our conviction that Democritus must rank below +Anaxagoras as a devotee of pure science. But, after all, such +comparisons and estimates as this are utterly futile. The +essential fact for us is that here, in the fifth century before +our era, we find put forward the most penetrating guess as to the +constitution of matter that the history of ancient thought has to +present to us. In one direction, the avenue of progress is +barred; there will be no farther step that way till we come down +the centuries to the time of Dalton. + + +HIPPOCRATES AND GREEK MEDICINE + +These studies of the constitution of matter have carried us to +the limits of the field of scientific imagination in antiquity; +let us now turn sharply and consider a department of science in +which theory joins hands with practicality. Let us witness the +beginnings of scientific therapeutics. + +Medicine among the early Greeks, before the time of Hippocrates, +was a crude mixture of religion, necromancy, and mysticism. +Temples were erected to the god of medicine, aesculapius, and +sick persons made their way, or were carried, to these temples, +where they sought to gain the favor of the god by suitable +offerings, and learn the way to regain their health through +remedies or methods revealed to them in dreams by the god. When +the patient had been thus cured, he placed a tablet in the temple +describing his sickness, and telling by what method the god had +cured him. He again made suitable offerings at the temple, which +were sometimes in the form of gold or silver representations of +the diseased organ--a gold or silver model of a heart, hand, +foot, etc. + +Nevertheless, despite this belief in the supernatural, many drugs +and healing lotions were employed, and the Greek physicians +possessed considerable skill in dressing wounds and bandaging. +But they did not depend upon these surgical dressings alone, +using with them certain appropriate prayers and incantations, +recited over the injured member at the time of applying the +dressings. + +Even the very early Greeks had learned something of anatomy. The +daily contact with wounds and broken bones must of necessity lead +to a crude understanding of anatomy in general. The first Greek +anatomist, however, who is recognized as such, is said to have +been Alcmaeon. He is said to have made extensive dissections of +the lower animals, and to have described many hitherto unknown +structures, such as the optic nerve and the Eustachian canal--the +small tube leading into the throat from the ear. He is credited +with many unique explanations of natural phenomena, such as, for +example, the explanation that "hearing is produced by the hollow +bone behind the ear; for all hollow things are sonorous." He was +a rationalist, and he taught that the brain is the organ of mind. +The sources of our information about his work, however, are +unreliable. + +Democedes, who lived in the sixth century B.C., is the first +physician of whom we have any trustworthy history. We learn from +Herodotus that he came from Croton to aegina, where, in +recognition of his skill, he was appointed medical officer of the +city. From aegina he was called to Athens at an increased salary, +and later was in charge of medical affairs in several other Greek +cities. He was finally called to Samos by the tyrant Polycrates, +who reigned there from about 536 to 522 B.C. But on the death of +Polycrates, who was murdered by the Persians, Democedes became a +slave. His fame as a physician, however, had reached the ears of +the Persian monarch, and shortly after his capture he was +permitted to show his skill upon King Darius himself. The Persian +monarch was suffering from a sprained ankle, which his Egyptian +surgeons had been unable to cure. Democedes not only cured the +injured member but used his influence in saving the lives of his +Egyptian rivals, who had been condemned to death by the king. + +At another time he showed his skill by curing the queen, who was +suffering from a chronic abscess of long standing. This so +pleased the monarch that he offered him as a reward anything he +might desire, except his liberty. But the costly gifts of Darius +did not satisfy him so long as he remained a slave; and +determined to secure his freedom at any cost, he volunteered to +lead some Persian spies into his native country, promising to use +his influence in converting some of the leading men of his nation +to the Persian cause. Laden with the wealth that had been heaped +upon him by Darius, he set forth upon his mission, but upon +reaching his native city of Croton he threw off his mask, +renounced his Persian mission, and became once more a free Greek. + +While the story of Democedes throws little light upon the medical +practices of the time, it shows that paid city medical officers +existed in Greece as early as the fifth and sixth centuries B.C. +Even then there were different "schools" of medicine, whose +disciples disagreed radically in their methods of treating +diseases; and there were also specialists in certain diseases, +quacks, and charlatans. Some physicians depended entirely upon +external lotions for healing all disorders; others were +"hydrotherapeutists" or "bath- physicians"; while there were a +host of physicians who administered a great variety of herbs and +drugs. There were also magicians who pretended to heal by +sorcery, and great numbers of bone-setters, oculists, and +dentists. + +Many of the wealthy physicians had hospitals, or clinics, where +patients were operated upon and treated. They were not hospitals +in our modern understanding of the term, but were more like +dispensaries, where patients were treated temporarily, but were +not allowed to remain for any length of time. Certain communities +established and supported these dispensaries for the care of the +poor. + +But anything approaching a rational system of medicine was not +established, until Hippocrates of Cos, the "father of medicine," +came upon the scene. In an age that produced Phidias, Lysias, +Herodotus, Sophocles, and Pericles, it seems but natural that the +medical art should find an exponent who would rise above +superstitious dogmas and lay the foundation for a medical +science. His rejection of the supernatural alone stamps the +greatness of his genius. But, besides this, he introduced more +detailed observation of diseases, and demonstrated the importance +that attaches to prognosis. + +Hippocrates was born at Cos, about 460 B.C., but spent most of +his life at Larissa, in Thessaly. He was educated as a physician +by his father, and travelled extensively as an itinerant +practitioner for several years. His travels in different climates +and among many different people undoubtedly tended to sharpen his +keen sense of observation. He was a practical physician as well +as a theorist, and, withal, a clear and concise writer. "Life is +short," he says, "opportunity fleeting, judgment difficult, +treatment easy, but treatment after thought is proper and +profitable." + +His knowledge of anatomy was necessarily very imperfect, and was +gained largely from his predecessors, to whom he gave full +credit. Dissections of the human body were forbidden him, and he +was obliged to confine his experimental researches to operations +on the lower animals. His knowledge of the structure and +arrangement of the bones, however, was fairly accurate, but the +anatomy of the softer tissues, as he conceived it, was a queer +jumbling together of blood-vessels, muscles, and tendons. He does +refer to "nerves," to be sure, but apparently the structures +referred to are the tendons and ligaments, rather than the nerves +themselves. He was better acquainted with the principal organs in +the cavities of the body, and knew, for example, that the heart +is divided into four cavities, two of which he supposed to +contain blood, and the other two air. + +His most revolutionary step was his divorcing of the supernatural +from the natural, and establishing the fact that disease is due +to natural causes and should be treated accordingly. The effect +of such an attitude can hardly be over-estimated. The +establishment of such a theory was naturally followed by a close +observation as to the course of diseases and the effects of +treatment. To facilitate this, he introduced the custom of +writing down his observations as he made them--the "clinical +history" of the case. Such clinical records are in use all over +the world to-day, and their importance is so obvious that it is +almost incomprehensible that they should have fallen into disuse +shortly after the time of Hippocrates, and not brought into +general use again until almost two thousand years later. + +But scarcely less important than his recognition of disease as a +natural phenomenon was the importance he attributed to prognosis. +Prognosis, in the sense of prophecy, was common before the time +of Hippocrates. But prognosis, as he practised it and as we +understand it to-day, is prophecy based on careful observation of +the course of diseases--something more than superstitious +conjecture. + +Although Hippocratic medicine rested on the belief in natural +causes, nevertheless, dogma and theory held an important place. +The humoral theory of disease was an all-important one, and so +fully was this theory accepted that it influenced the science of +medicine all through succeeding centuries. According to this +celebrated theory there are four humors in the body-- blood, +phlegm, yellow bile, and black bile. When these humors are mixed +in exact proportions they constitute health; but any deviations +from these proportions produce disease. In treating diseases the +aim of the physician was to discover which of these humors were +out of proportion and to restore them to their natural +equilibrium. It was in the methods employed in this restitution, +rather than a disagreement about the humors themselves, that +resulted in the various "schools" of medicine. + +In many ways the surgery of Hippocrates showed a better +understanding of the structure of the organs than of their +functions. Some of the surgical procedures as described by him +are followed, with slight modifications, to-day. Many of his +methods were entirely lost sight of until modern times, and one, +the treatment of dislocation of the outer end of the collar-bone, +was not revived until some time in the eighteenth century. + +Hippocrates, it seems, like modern physicians, sometimes suffered +from the ingratitude of his patients. "The physician visits a +patient suffering from fever or a wound, and prescribes for him," +he says; "on the next day, if the patient feels worse the blame +is laid upon the physician; if, on the other hand, he feels +better, nature is extolled, and the physician reaps no praise." +The essence of this has been repeated in rhyme and prose by +writers in every age and country, but the "father of medicine" +cautions physicians against allowing it to influence their +attitude towards their profession. + + + +VIII. POST-SOCRATIC SCIENCE AT ATHENS--PLATO, ARISTOTLE, AND +THEOPHRASTUS + +Doubtless it has been noticed that our earlier scientists were as +far removed as possible from the limitations of specialism. In +point of fact, in this early day, knowledge had not been +classified as it came to be later on. The philosopher was, as his +name implied, a lover of knowledge, and he did not find it beyond +the reach of his capacity to apply himself to all departments of +the field of human investigation. It is nothing strange to +discover that Anaximander and the Pythagoreans and Anaxagoras +have propounded theories regarding the structure of the cosmos, +the origin and development of animals and man, and the nature of +matter itself. Nowadays, so enormously involved has become the +mass of mere facts regarding each of these departments of +knowledge that no one man has the temerity to attempt to master +them all. But it was different in those days of beginnings. Then +the methods of observation were still crude, and it was quite the +custom for a thinker of forceful personality to find an eager +following among disciples who never thought of putting his +theories to the test of experiment. The great lesson that true +science in the last resort depends upon observation and +measurement, upon compass and balance, had not yet been learned, +though here and there a thinker like Anaxagoras had gained an +inkling of it. + +For the moment, indeed, there in Attica, which was now, thanks to +that outburst of Periclean culture, the centre of the world's +civilization, the trend of thought was to take quite another +direction. The very year which saw the birth of Democritus at +Abdera, and of Hippocrates, marked also the birth, at Athens, of +another remarkable man, whose influence it would scarcely be +possible to over-estimate. This man was Socrates. The main facts +of his history are familiar to every one. It will be recalled +that Socrates spent his entire life in Athens, mingling +everywhere with the populace; haranguing, so the tradition goes, +every one who would listen; inculcating moral lessons, and +finally incurring the disapprobation of at least a voting +majority of his fellow-citizens. He gathered about him a company +of remarkable men with Plato at their head, but this could not +save him from the disapprobation of the multitudes, at whose +hands he suffered death, legally administered after a public +trial. The facts at command as to certain customs of the Greeks +at this period make it possible to raise a question as to whether +the alleged "corruption of youth," with which Socrates was +charged, may not have had a different implication from what +posterity has preferred to ascribe to it. But this thought, +almost shocking to the modern mind and seeming altogether +sacrilegious to most students of Greek philosophy, need not here +detain us; neither have we much concern in the present connection +with any part of the teaching of the martyred philosopher. For +the historian of metaphysics, Socrates marks an epoch, but for +the historian of science he is a much less consequential figure. + +Similarly regarding Plato, the aristocratic Athenian who sat at +the feet of Socrates, and through whose writings the teachings of +the master found widest currency. Some students of philosophy +find in Plato "the greatest thinker and writer of all time."[1] +The student of science must recognize in him a thinker whose +point of view was essentially non-scientific; one who tended +always to reason from the general to the particular rather than +from the particular to the general. Plato's writings covered +almost the entire field of thought, and his ideas were presented +with such literary charm that successive generations of readers +turned to them with unflagging interest, and gave them wide +currency through copies that finally preserved them to our own +time. Thus we are not obliged in his case, as we are in the case +of every other Greek philosopher, to estimate his teachings +largely from hearsay evidence. Plato himself speaks to us +directly. It is true, the literary form which he always adopted, +namely, the dialogue, does not give quite the same certainty as +to when he is expressing his own opinions that a more direct +narrative would have given; yet, in the main, there is little +doubt as to the tenor of his own opinions--except, indeed, such +doubt as always attaches to the philosophical reasoning of the +abstract thinker. + +What is chiefly significant from our present standpoint is that +the great ethical teacher had no significant message to give the +world regarding the physical sciences. He apparently had no +sharply defined opinions as to the mechanism of the universe; no +clear conception as to the origin or development of organic +beings; no tangible ideas as to the problems of physics; no +favorite dreams as to the nature of matter. Virtually his back +was turned on this entire field of thought. He was under the sway +of those innate ideas which, as we have urged, were among the +earliest inductions of science. But he never for a moment +suspected such an origin for these ideas. He supposed his +conceptions of being, his standards of ethics, to lie back of all +experience; for him they were the most fundamental and most +dependable of facts. He criticised Anaxagoras for having tended +to deduce general laws from observation. As we moderns see it, +such criticism is the highest possible praise. It is a criticism +that marks the distinction between the scientist who is also a +philosopher and the philosopher who has but a vague notion of +physical science. Plato seemed, indeed, to realize the value of +scientific investigation; he referred to the astronomical studies +of the Egyptians and Chaldeans, and spoke hopefully of the +results that might accrue were such studies to be taken up by +that Greek mind which, as he justly conceived, had the power to +vitalize and enrich all that it touched. But he told here of what +he would have others do, not of what he himself thought of doing. +His voice was prophetic, but it stimulated no worker of his own +time. + +Plato himself had travelled widely. It is a familiar legend that +he lived for years in Egypt, endeavoring there to penetrate the +mysteries of Egyptian science. It is said even that the rudiments +of geometry which he acquired there influenced all his later +teachings. But be that as it may, the historian of science must +recognize in the founder of the Academy a moral teacher and +metaphysical dreamer and sociologist, but not, in the modern +acceptance of the term, a scientist. Those wider phases of +biological science which find their expression in metaphysics, in +ethics, in political economy, lie without our present scope; and +for the development of those subjects with which we are more +directly concerned, Plato, like his master, has a negative +significance. + + +ARISTOTLE (384-322 B.C.) + +When we pass to that third great Athenian teacher, Aristotle, the +case is far different. Here was a man whose name was to be +received as almost a synonym for Greek science for more than a +thousand years after his death. All through the Middle Ages his +writings were to be accepted as virtually the last word regarding +the problems of nature. We shall see that his followers actually +preferred his mandate to the testimony of their own senses. We +shall see, further, that modern science progressed somewhat in +proportion as it overthrew the Aristotelian dogmas. But the +traditions of seventeen or eighteen centuries are not easily set +aside, and it is perhaps not too much to say that the name of +Aristotle stands, even in our own time, as vaguely representative +in the popular mind of all that was highest and best in the +science of antiquity. Yet, perhaps, it would not be going too far +to assert that something like a reversal of this judgment would +be nearer the truth. Aristotle did, indeed, bring together a +great mass of facts regarding animals in his work on natural +history, which, being preserved, has been deemed to entitle its +author to be called the "father of zoology." But there is no +reason to suppose that any considerable portion of this work +contained matter that was novel, or recorded observations that +were original with Aristotle; and the classifications there +outlined are at best but a vague foreshadowing of the elaboration +of the science. Such as it is, however, the natural history +stands to the credit of the Stagirite. He must be credited, too, +with a clear enunciation of one most important scientific +doctrine--namely, the doctrine of the spherical figure of the +earth. We have already seen that this theory originated with the +Pythagorean philosophers out in Italy. We have seen, too, that +the doctrine had not made its way in Attica in the time of +Anaxagoras. But in the intervening century it had gained wide +currency, else so essentially conservative a thinker as Aristotle +would scarcely have accepted it. He did accept it, however, and +gave the doctrine clearest and most precise expression. Here are +his words:[2] + + +"As to the figure of the earth it must necessarily be +spherical.... If it were not so, the eclipses of the moon would +not have such sections as they have. For in the configurations in +the course of a month the deficient part takes all different +shapes; it is straight, and concave, and convex; but in eclipses +it always has the line of divisions convex; wherefore, since the +moon is eclipsed in consequence of the interposition of the +earth, the periphery of the earth must be the cause of this by +having a spherical form. And again, from the appearance of the +stars it is clear, not only that the earth is round, but that its +size is not very large; for when we make a small removal to the +south or the north, the circle of the horizon becomes palpably +different, so that the stars overhead undergo a great change, and +are not the same to those that travel in the north and to the +south. For some stars are seen in Egypt or at Cyprus, but are not +seen in the countries to the north of these; and the stars that +in the north are visible while they make a complete circuit, +there undergo a setting. So that from this it is manifest, not +only that the form of the earth is round, but also that it is a +part of a not very large sphere; for otherwise the difference +would not be so obvious to persons making so small a change of +place. Wherefore we may judge that those persons who connect the +region in the neighborhood of the pillars of Hercules with that +towards India, and who assert that in this way the sea is one, do +not assert things very improbable. They confirm this conjecture +moreover by the elephants, which are said to be of the same +species towards each extreme; as if this circumstance was a +consequence of the conjunction of the extremes. The +mathematicians who try to calculate the measure of the +circumference, make it amount to four hundred thousand stadia; +whence we collect that the earth is not only spherical, but is +not large compared with the magnitude of the other stars." + +But in giving full meed of praise to Aristotle for the +promulgation of this doctrine of the sphericity of the earth, it +must unfortunately be added that the conservative philosopher +paused without taking one other important step. He could not +accept, but, on the contrary, he expressly repudiated, the +doctrine of the earth's motion. We have seen that this idea also +was a part of the Pythagorean doctrine, and we shall have +occasion to dwell more at length on this point in a succeeding +chapter. It has even been contended by some critics that it was +the adverse conviction of the Peripatetic philosopher which, more +than any other single influence, tended to retard the progress of +the true doctrine regarding the mechanism of the heavens. +Aristotle accepted the sphericity of the earth, and that doctrine +became a commonplace of scientific knowledge, and so continued +throughout classical antiquity. But Aristotle rejected the +doctrine of the earth's motion, and that doctrine, though +promulgated actively by a few contemporaries and immediate +successors of the Stagirite, was then doomed to sink out of view +for more than a thousand years. If it be a correct assumption +that the influence of Aristotle was, in a large measure, +responsible for this result, then we shall perhaps not be far +astray in assuming that the great founder of the Peripatetic +school was, on the whole, more instrumental in retarding the +progress of astronomical science that any other one man that ever +lived. + +The field of science in which Aristotle was pre-eminently a +pathfinder is zoology. His writings on natural history have +largely been preserved, and they constitute by far the most +important contribution to the subject that has come down to us +from antiquity. They show us that Aristotle had gained possession +of the widest range of facts regarding the animal kingdom, and, +what is far more important, had attempted to classify these +facts. In so doing he became the founder of systematic zoology. +Aristotle's classification of the animal kingdom was known and +studied throughout the Middle Ages, and, in fact, remained in +vogue until superseded by that of Cuvier in the nineteenth +century. It is not to be supposed that all the terms of +Aristotle's classification originated with him. Some of the +divisions are too patent to have escaped the observation of his +predecessors. Thus, for example, the distinction between birds +and fishes as separate classes of animals is so obvious that it +must appeal to a child or to a savage. But the efforts of +Aristotle extended, as we shall see, to less patent +generalizations. At the very outset, his grand division of the +animal kingdom into blood-bearing and bloodless animals implies a +very broad and philosophical conception of the entire animal +kingdom. The modern physiologist does not accept the +classification, inasmuch as it is now known that colorless fluids +perform the functions of blood for all the lower organisms. But +the fact remains that Aristotle's grand divisions correspond to +the grand divisions of the Lamarckian system--vertebrates and +invertebrates-- which every one now accepts. Aristotle, as we +have said, based his classification upon observation of the +blood; Lamarck was guided by a study of the skeleton. The fact +that such diverse points of view could direct the observer +towards the same result gives, inferentially, a suggestive lesson +in what the modern physiologist calls the homologies of parts of +the organism. + +Aristotle divides his so-called blood-bearing animals into five +classes: (1) Four-footed animals that bring forth their young +alive; (2) birds; (3) egg-laying four- footed animals (including +what modern naturalists call reptiles and amphibians); (4) whales +and their allies; (5) fishes. This classification, as will be +observed, is not so very far afield from the modern divisions +into mammals, birds, reptiles, amphibians, and fishes. That +Aristotle should have recognized the fundamental distinction +between fishes and the fish- like whales, dolphins, and porpoises +proves the far from superficial character of his studies. +Aristotle knew that these animals breathe by means of lungs and +that they produce living young. He recognized, therefore, their +affinity with his first class of animals, even if he did not, +like the modern naturalist, consider these affinities close +enough to justify bringing the two types together into a single +class. + +The bloodless animals were also divided by Aristotle into five +classes--namely: (1) Cephalopoda (the octopus, cuttle-fish, +etc.); (2) weak-shelled animals (crabs, etc.); (3) insects and +their allies (including various forms, such as spiders and +centipedes, which the modern classifier prefers to place by +themselves); (4) hard-shelled animals (clams, oysters, snails, +etc.); (5) a conglomerate group of marine forms, including +star-fish, sea-urchins, and various anomalous forms that were +regarded as linking the animal to the vegetable worlds. This +classification of the lower forms of animal life continued in +vogue until Cuvier substituted for it his famous grouping into +articulates, mollusks, and radiates; which grouping in turn was +in part superseded later in the nineteenth century. + +What Aristotle did for the animal kingdom his pupil, +Theophrastus, did in some measure for the vegetable kingdom. +Theophrastus, however, was much less a classifier than his +master, and his work on botany, called The Natural History of +Development, pays comparatively slight attention to theoretical +questions. It deals largely with such practicalities as the +making of charcoal, of pitch, and of resin, and the effects of +various plants on the animal organism when taken as foods or as +medicines. In this regard the work of Theophrastus, is more +nearly akin to the natural history of the famous Roman compiler, +Pliny. It remained, however, throughout antiquity as the most +important work on its subject, and it entitles Theophrastus to be +called the "father of botany." Theophrastus deals also with the +mineral kingdom after much the same fashion, and here again his +work is the most notable that was produced in antiquity. + + + +IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC PERIOD + +We are entering now upon the most important scientific epoch of +antiquity. When Aristotle and Theophrastus passed from the scene, +Athens ceased to be in any sense the scientific centre of the +world. That city still retained its reminiscent glory, and cannot +be ignored in the history of culture, but no great scientific +leader was ever again to be born or to take up his permanent +abode within the confines of Greece proper. With almost +cataclysmic suddenness, a new intellectual centre appeared on the +south shore of the Mediterranean. This was the city of +Alexandria, a city which Alexander the Great had founded during +his brief visit to Egypt, and which became the capital of Ptolemy +Soter when he chose Egypt as his portion of the dismembered +empire of the great Macedonian. Ptolemy had been with his master +in the East, and was with him in Babylonia when he died. He had +therefore come personally in contact with Babylonian +civilization, and we cannot doubt that this had a most important +influence upon his life, and through him upon the new +civilization of the West. In point of culture, Alexandria must be +regarded as the successor of Babylon, scarcely less directly than +of Greece. Following the Babylonian model, Ptolemy erected a +great museum and began collecting a library. Before his death it +was said that he had collected no fewer than two hundred thousand +manuscripts. He had gathered also a company of great teachers and +founded a school of science which, as has just been said, made +Alexandria the culture-centre of the world. + +Athens in the day of her prime had known nothing quite like this. +Such private citizens as Aristotle are known to have had +libraries, but there were no great public collections of books in +Athens, or in any other part of the Greek domain, until Ptolemy +founded his famous library. As is well known, such libraries had +existed in Babylonia for thousands of years. The character which +the Ptolemaic epoch took on was no doubt due to Babylonian +influence, but quite as much to the personal experience of +Ptolemy himself as an explorer in the Far East. The marvellous +conquering journey of Alexander had enormously widened the +horizon of the Greek geographer, and stimulated the imagination +of all ranks of the people, It was but natural, then, that +geography and its parent science astronomy should occupy the +attention of the best minds in this succeeding epoch. In point of +fact, such a company of star-gazers and earth-measurers came upon +the scene in this third century B.C. as had never before existed +anywhere in the world. The whole trend of the time was towards +mechanics. It was as if the greatest thinkers had squarely faced +about from the attitude of the mystical philosophers of the +preceding century, and had set themselves the task of solving all +the mechanical riddles of the universe, They no longer troubled +themselves about problems of "being" and "becoming"; they gave +but little heed to metaphysical subtleties; they demanded that +their thoughts should be gauged by objective realities. Hence +there arose a succession of great geometers, and their +conceptions were applied to the construction of new mechanical +contrivances on the one hand, and to the elaboration of theories +of sidereal mechanics on the other. + +The wonderful company of men who performed the feats that are +about to be recorded did not all find their home in Alexandria, +to be sure; but they all came more or less under the Alexandrian +influence. We shall see that there are two other important +centres; one out in Sicily, almost at the confines of the Greek +territory in the west; the other in Asia Minor, notably on the +island of Samos--the island which, it will be recalled, was at an +earlier day the birthplace of Pythagoras. But whereas in the +previous century colonists from the confines of the civilized +world came to Athens, now all eyes turned towards Alexandria, and +so improved were the facilities for communication that no doubt +the discoveries of one coterie of workers were known to all the +others much more quickly than had ever been possible before. We +learn, for example, that the studies of Aristarchus of Samos were +definitely known to Archimedes of Syracuse, out in Sicily. +Indeed, as we shall see, it is through a chance reference +preserved in one of the writings of Archimedes that one of the +most important speculations of Aristarchus is made known to us. +This illustrates sufficiently the intercommunication through +which the thought of the Alexandrian epoch was brought into a +single channel. We no longer, as in the day of the earlier +schools of Greek philosophy, have isolated groups of thinkers. +The scientific drama is now played out upon a single stage; and +if we pass, as we shall in the present chapter, from Alexandria +to Syracuse and from Syracuse to Samos, the shift of scenes does +no violence to the dramatic unities. + +Notwithstanding the number of great workers who were not properly +Alexandrians, none the less the epoch is with propriety termed +Alexandrian. Not merely in the third century B.C., but throughout +the lapse of at least four succeeding centuries, the city of +Alexander and the Ptolemies continued to hold its place as the +undisputed culture-centre of the world. During that period Rome +rose to its pinnacle of glory and began to decline, without ever +challenging the intellectual supremacy of the Egyptian city. We +shall see, in a later chapter, that the Alexandrian influences +were passed on to the Mohammedan conquerors, and every one is +aware that when Alexandria was finally overthrown its place was +taken by another Greek city, Byzantium or Constantinople. But +that transfer did not occur until Alexandria had enjoyed a longer +period of supremacy as an intellectual centre than had perhaps +ever before been granted to any city, with the possible +exception of Babylon. + + +EUCLID (ABOUT 300 B.C.) + +Our present concern is with that first wonderful development of +scientific activity which began under the first Ptolemy, and +which presents, in the course of the first century of Alexandrian +influence, the most remarkable coterie of scientific workers and +thinkers that antiquity produced. The earliest group of these new +leaders in science had at its head a man whose name has been a +household word ever since. This was Euclid, the father of +systematic geometry. Tradition has preserved to us but little of +the personality of this remarkable teacher; but, on the other +hand, his most important work has come down to us in its +entirety. The Elements of Geometry, with which the name of Euclid +is associated in the mind of every school-boy, presented the +chief propositions of its subject in so simple and logical a form +that the work remained a textbook everywhere for more than two +thousand years. Indeed it is only now beginning to be superseded. +It is not twenty years since English mathematicians could deplore +the fact that, despite certain rather obvious defects of the work +of Euclid, no better textbook than this was available. Euclid's +work, of course, gives expression to much knowledge that did not +originate with him. We have already seen that several important +propositions of geometry had been developed by Thales, and one by +Pythagoras, and that the rudiments of the subject were at least +as old as Egyptian civilization. Precisely how much Euclid added +through his own investigations cannot be ascertained. It seems +probable that he was a diffuser of knowledge rather than an +originator, but as a great teacher his fame is secure. He is +credited with an epigram which in itself might insure him +perpetuity of fame: "There is no royal road to geometry," was his +answer to Ptolemy when that ruler had questioned whether the +Elements might not be simplified. Doubtless this, like most +similar good sayings, is apocryphal; but whoever invented it has +made the world his debtor. + + +HEROPHILUS AND ERASISTRATUS + +The catholicity of Ptolemy's tastes led him, naturally enough, to +cultivate the biological no less than the physical sciences. In +particular his influence permitted an epochal advance in the +field of medicine. Two anatomists became famous through the +investigations they were permitted to make under the patronage of +the enlightened ruler. These earliest of really scientific +investigators of the mechanism of the human body were named +Herophilus and Erasistratus. These two anatomists gained their +knowledge by the dissection of human bodies (theirs are the first +records that we have of such practices), and King Ptolemy himself +is said to have been present at some of these dissections. They +were the first to discover that the nerve- trunks have their +origin in the brain and spinal cord, and they are credited also +with the discovery that these nerve-trunks are of two different +kinds--one to convey motor, and the other sensory impulses. They +discovered, described, and named the coverings of the brain. The +name of Herophilus is still applied by anatomists, in honor of +the discoverer, to one of the sinuses or large canals that convey +the venous blood from the head. Herophilus also noticed and +described four cavities or ventricles in the brain, and reached +the conclusion that one of these ventricles was the seat of the +soul--a belief shared until comparatively recent times by many +physiologists. He made also a careful and fairly accurate study +of the anatomy of the eye, a greatly improved the old operation +for cataract. + +With the increased knowledge of anatomy came also corresponding +advances in surgery, and many experimental operations are said to +have been performed upon condemned criminals who were handed over +to the surgeons by the Ptolemies. While many modern writers have +attempted to discredit these assertions, it is not improbable +that such operations were performed. In an age when human life +was held so cheap, and among a people accustomed to torturing +condemned prisoners for comparatively slight offences, it is not +unlikely that the surgeons were allowed to inflict perhaps less +painful tortures in the cause of science. Furthermore, we know +that condemned criminals were sometimes handed over to the +medical profession to be "operated upon and killed in whatever +way they thought best" even as late as the sixteenth century. +Tertullian[1] probably exaggerates, however, when he puts the +number of such victims in Alexandria at six hundred. + +Had Herophilus and Erasistratus been as happy in their deductions +as to the functions of the organs as they were in their knowledge +of anatomy, the science of medicine would have been placed upon a +very high plane even in their time. Unfortunately, however, they +not only drew erroneous inferences as to the functions of the +organs, but also disagreed radically as to what functions certain +organs performed, and how diseases should be treated, even when +agreeing perfectly on the subject of anatomy itself. Their +contribution to the knowledge of the scientific treatment of +diseases holds no such place, therefore, as their anatomical +investigations. + +Half a century after the time of Herophilus there appeared a +Greek physician, Heraclides, whose reputation in the use of drugs +far surpasses that of the anatomists of the Alexandrian school. +His reputation has been handed down through the centuries as that +of a physician, rather than a surgeon, although in his own time +he was considered one of the great surgeons of the period. +Heraclides belonged to the "Empiric" school, which rejected +anatomy as useless, depending entirely on the use of drugs. He is +thought to have been the first physician to point out the value +of opium in certain painful diseases. His prescription of this +drug for certain cases of "sleeplessness, spasm, cholera, and +colic," shows that his use of it was not unlike that of the +modern physician in certain cases; and his treatment of fevers, +by keeping the patient's head cool and facilitating the +secretions of the body, is still recognized as "good practice." +He advocated a free use of liquids in quenching the fever +patient's thirst--a recognized therapeutic measure to-day, but +one that was widely condemned a century ago. + + +ARCHIMEDES OF SYRACUSE AND THE FOUNDATION OF MECHANICS + +We do not know just when Euclid died, but as he was at the height +of his fame in the time of Ptolemy I., whose reign ended in the +year 285 B.C., it is hardly probable that he was still living +when a young man named Archimedes came to Alexandria to study. +Archimedes was born in the Greek colony of Syracuse, on the +island of Sicily, in the year 287 B.C. When he visited Alexandria +he probably found Apollonius of Perga, the pupil of Euclid, at +the head of the mathematical school there. Just how long +Archimedes remained at Alexandria is not known. When he had +satisfied his curiosity or completed his studies, he returned to +Syracuse and spent his life there, chiefly under the patronage of +King Hiero, who seems fully to have appreciated his abilities. + +Archimedes was primarily a mathematician. Left to his own +devices, he would probably have devoted his entire time to the +study of geometrical problems. But King Hiero had discovered that +his protege had wonderful mechanical ingenuity, and he made good +use of this discovery. Under stress of the king's urgings, the +philosopher was led to invent a great variety of mechanical +contrivances, some of them most curious ones. Antiquity credited +him with the invention of more than forty machines, and it is +these, rather than his purely mathematical discoveries, that gave +his name popular vogue both among his contemporaries and with +posterity. Every one has heard of the screw of Archimedes, +through which the paradoxical effect was produced of making water +seem to flow up hill. The best idea of this curious mechanism is +obtained if one will take in hand an ordinary corkscrew, and +imagine this instrument to be changed into a hollow tube, +retaining precisely the same shape but increased to some feet in +length and to a proportionate diameter. If one will hold the +corkscrew in a slanting direction and turn it slowly to the +right, supposing that the point dips up a portion of water each +time it revolves, one can in imagination follow the flow of that +portion of water from spiral to spiral, the water always running +downward, of course, yet paradoxically being lifted higher and +higher towards the base of the corkscrew, until finally it pours +out (in the actual Archimedes' tube) at the top. There is another +form of the screw in which a revolving spiral blade operates +within a cylinder, but the principle is precisely the same. With +either form water may be lifted, by the mere turning of the +screw, to any desired height. The ingenious mechanism excited the +wonder of the contemporaries of Archimedes, as well it might. +More efficient devices have superseded it in modern times, but it +still excites the admiration of all who examine it, and its +effects seem as paradoxical as ever. + +Some other of the mechanisms of Archimedes have been made known +to successive generations of readers through the pages of +Polybius and Plutarch. These are the devices through which +Archimedes aided King Hiero to ward off the attacks of the Roman +general Marcellus, who in the course of the second Punic war laid +siege to Syracuse. + +Plutarch, in his life of Marcellus, describes the Roman's attack +and Archimedes' defence in much detail. Incidentally he tells us +also how Archimedes came to make the devices that rendered the +siege so famous: + +"Marcellus himself, with threescore galleys of five rowers at +every bank, well armed and full of all sorts of artillery and +fireworks, did assault by sea, and rowed hard to the wall, having +made a great engine and device of battery, upon eight galleys +chained together, to batter the wall: trusting in the great +multitude of his engines of battery, and to all such other +necessary provision as he had for wars, as also in his own +reputation. But Archimedes made light account of all his devices, +as indeed they were nothing comparable to the engines himself had +invented. This inventive art to frame instruments and engines +(which are called mechanical, or organical, so highly commended +and esteemed of all sorts of people) was first set forth by +Architas, and by Eudoxus: partly to beautify a little the science +of geometry by this fineness, and partly to prove and confirm by +material examples and sensible instruments, certain geometrical +conclusions, where of a man cannot find out the conceivable +demonstrations by enforced reasons and proofs. As that conclusion +which instructeth one to search out two lines mean proportional, +which cannot be proved by reason demonstrative, and yet +notwithstanding is a principle and an accepted ground for many +things which are contained in the art of portraiture. Both of +them have fashioned it to the workmanship of certain instruments, +called mesolabes or mesographs, which serve to find these mean +lines proportional, by drawing certain curve lines, and +overthwart and oblique sections. But after that Plato was +offended with them, and maintained against them, that they did +utterly corrupt and disgrace, the worthiness and excellence of +geometry, making it to descend from things not comprehensible and +without body, unto things sensible and material, and to bring it +to a palpable substance, where the vile and base handiwork of man +is to be employed: since that time, I say, handicraft, or the art +of engines, came to be separated from geometry, and being long +time despised by the philosophers, it came to be one of the +warlike arts. + +"But Archimedes having told King Hiero, his kinsman and friend, +that it was possible to remove as great a weight as he would, +with as little strength as he listed to put to it: and boasting +himself thus (as they report of him) and trusting to the force of +his reasons, wherewith he proved this conclusion, that if there +were another globe of earth, he was able to remove this of ours, +and pass it over to the other: King Hiero wondering to hear him, +required him to put his device in execution, and to make him see +by experience, some great or heavy weight removed, by little +force. So Archimedes caught hold with a book of one of the +greatest carects, or hulks of the king (that to draw it to the +shore out of the water required a marvellous number of people to +go about it, and was hardly to be done so) and put a great number +of men more into her, than her ordinary burden: and he himself +sitting alone at his ease far off, without any straining at all, +drawing the end of an engine with many wheels and pulleys, fair +and softly with his hand, made it come as gently and smoothly to +him, as it had floated in the sea. The king wondering to see the +sight, and knowing by proof the greatness of his art; be prayed +him to make him some engines, both to assault and defend, in all +manner of sieges and assaults. So Archimedes made him many +engines, but King Hiero never occupied any of them, because he +reigned the most part of his time in peace without any wars. But +this provision and munition of engines, served the Syracusan's +turn marvellously at that time: and not only the provision of the +engines ready made, but also the engineer and work-master +himself, that had invented them. + +"Now the Syracusans, seeing themselves assaulted by the Romans, +both by sea and by land, were marvellously perplexed, and could +not tell what to say, they were so afraid: imagining it was +impossible for them to withstand so great an army. But when +Archimedes fell to handling his engines, and to set them at +liberty, there flew in the air infinite kinds of shot, and +marvellous great stones, with an incredible noise and force on +the sudden, upon the footmen that came to assault the city by +land, bearing down, and tearing in pieces all those which came +against them, or in what place soever they lighted, no earthly +body being able to resist the violence of so heavy a weight: so +that all their ranks were marvellously disordered. And as for the +galleys that gave assault by sea, some were sunk with long pieces +of timber like unto the yards of ships, whereto they fasten their +sails, which were suddenly blown over the walls with force of +their engines into their galleys, and so sunk them by their over +great weight." + + +Polybius describes what was perhaps the most important of these +contrivances, which was, he tells us, "a band of iron, hanging by +a chain from the beak of a machine, which was used in the +following manner. The person who, like a pilot, guided the beak, +having let fall the hand, and catched hold of the prow of any +vessel, drew down the opposite end of the machine that was on the +inside of the walls. And when the vessel was thus raised erect +upon its stem, the machine itself was held immovable; but, the +chain being suddenly loosened from the beak by the means of +pulleys, some of the vessels were thrown upon their sides, others +turned with the bottom upwards; and the greatest part, as the +prows were plunged from a considerable height into the sea, were +filled with water, and all that were on board thrown into tumult +and disorder. + +"Marcellus was in no small degree embarrassed," Polybius +continues, "when he found himself encountered in every attempt by +such resistance. He perceived that all his efforts were defeated +with loss; and were even derided by the enemy. But, amidst all +the anxiety that he suffered, he could not help jesting upon the +inventions of Archimedes. This man, said he, employs our ships as +buckets to draw water: and boxing about our sackbuts, as if they +were unworthy to be associated with him, drives them from his +company with disgrace. Such was the success of the siege on the +side of the sea." + +Subsequently, however, Marcellus took the city by strategy, and +Archimedes was killed, contrary, it is said, to the express +orders of Marcellus. "Syracuse being taken," says Plutarch, +"nothing grieved Marcellus more than the loss of Archimedes. Who, +being in his study when the city was taken, busily seeking out by +himself the demonstration of some geometrical proposition which +he had drawn in figure, and so earnestly occupied therein, as he +neither saw nor heard any noise of enemies that ran up and down +the city, and much less knew it was taken: he wondered when he +saw a soldier by him, that bade him go with him to Marcellus. +Notwithstanding, he spake to the soldier, and bade him tarry +until he had done his conclusion, and brought it to +demonstration: but the soldier being angry with his answer, drew +out his sword and killed him. Others say, that the Roman soldier +when he came, offered the sword's point to him, to kill him: and +that Archimedes when he saw him, prayed him to hold his hand a +little, that he might not leave the matter he looked for +imperfect, without demonstration. But the soldier making no +reckoning of his speculation, killed him presently. It is +reported a third way also, saying that certain soldiers met him +in the streets going to Marcellus, carrying certain mathematical +instruments in a little pretty coffer, as dials for the sun, +spheres, and angles, wherewith they measure the greatness of the +body of the sun by view: and they supposing he had carried some +gold or silver, or other precious jewels in that little coffer, +slew him for it. But it is most certain that Marcellus was +marvellously sorry for his death, and ever after hated the +villain that slew him, as a cursed and execrable person: and how +he had made also marvellous much afterwards of Archimedes' +kinsmen for his sake." + +We are further indebted to Plutarch for a summary of the +character and influence of Archimedes, and for an interesting +suggestion as to the estimate which the great philosopher put +upon the relative importance of his own discoveries. +"Notwithstanding Archimedes had such a great mind, and was so +profoundly learned, having hidden in him the only treasure and +secrets of geometrical inventions: as be would never set forth +any book how to make all these warlike engines, which won him at +that time the fame and glory, not of man's knowledge, but rather +of divine wisdom. But he esteeming all kind of handicraft and +invention to make engines, and generally all manner of sciences +bringing common commodity by the use of them, to be but vile, +beggarly, and mercenary dross: employed his wit and study only to +write things, the beauty and subtlety whereof were not mingled +anything at all with necessity. For all that he hath written, are +geometrical propositions, which are without comparison of any +other writings whatsoever: because the subject where of they +treat, doth appear by demonstration, the maker gives them the +grace and the greatness, and the demonstration proving it so +exquisitely, with wonderful reason and facility, as it is not +repugnable. For in all geometry are not to be found more profound +and difficult matters written, in more plain and simple terms, +and by more easy principles, than those which he hath invented. +Now some do impute this, to the sharpness of his wit and +understanding, which was a natural gift in him: others do refer +it to the extreme pains he took, which made these things come so +easily from him, that they seemed as if they had been no trouble +to him at all. For no man living of himself can devise the +demonstration of his propositions, what pains soever he take to +seek it: and yet straight so soon as he cometh to declare and +open it, every man then imagineth with himself he could have +found it out well enough, he can then so plainly make +demonstration of the thing he meaneth to show. And therefore that +methinks is likely to be true, which they write of him: that he +was so ravished and drunk with the sweet enticements of this +siren, which as it were lay continually with him, as he forgot +his meat and drink, and was careless otherwise of himself, that +oftentimes his servants got him against his will to the baths to +wash and anoint him: and yet being there, he would ever be +drawing out of the geometrical figures, even in the very imbers +of the chimney. And while they were anointing of him with oils +and sweet savours, with his finger he did draw lines upon his +naked body: so far was he taken from himself, and brought into an +ecstasy or trance, with the delight he had in the study of +geometry, and truly ravished with the love of the Muses. But +amongst many notable things he devised, it appeareth, that he +most esteemed the demonstration of the proportion between the +cylinder (to wit, the round column) and the sphere or globe +contained in the same: for he prayed his kinsmen and friends, +that after his death they would put a cylinder upon his tomb, +containing a massy sphere, with an inscription of the proportion, +whereof the continent exceedeth the thing contained."[2] + +It should be observed that neither Polybius nor Plutarch mentions +the use of burning-glasses in connection with the siege of +Syracuse, nor indeed are these referred to by any other ancient +writer of authority. Nevertheless, a story gained credence down +to a late day to the effect that Archimedes had set fire to the +fleet of the enemy with the aid of concave mirrors. An experiment +was made by Sir Isaac Newton to show the possibility of a +phenomenon so well in accord with the genius of Archimedes, but +the silence of all the early authorities makes it more than +doubtful whether any such expedient was really adopted. + +It will be observed that the chief principle involved in all +these mechanisms was a capacity to transmit great power through +levers and pulleys, and this brings us to the most important +field of the Syracusan philosopher's activity. It was as a +student of the lever and the pulley that Archimedes was led to +some of his greatest mechanical discoveries. He is even credited +with being the discoverer of the compound pulley. More likely he +was its developer only, since the principle of the pulley was +known to the old Babylonians, as their sculptures testify. But +there is no reason to doubt the general outlines of the story +that Archimedes astounded King Hiero by proving that, with the +aid of multiple pulleys, the strength of one man could suffice to +drag the largest ship from its moorings. + +The property of the lever, from its fundamental principle, was +studied by him, beginning with the self- evident fact that "equal +bodies at the ends of the equal arms of a rod, supported on its +middle point, will balance each other"; or, what amounts to the +same thing stated in another way, a regular cylinder of uniform +matter will balance at its middle point. From this starting-point +he elaborated the subject on such clear and satisfactory +principles that they stand to-day practically unchanged and with +few additions. From all his studies and experiments he finally +formulated the principle that "bodies will be in equilibrio when +their distance from the fulcrum or point of support is inversely +as their weight." He is credited with having summed up his +estimate of the capabilities of the lever with the well-known +expression, "Give me a fulcrum on which to rest or a place on +which to stand, and I will move the earth." + +But perhaps the feat of all others that most appealed to the +imagination of his contemporaries, and possibly also the one that +had the greatest bearing upon the position of Archimedes as a +scientific discoverer, was the one made familiar through the tale +of the crown of Hiero. This crown, so the story goes, was +supposed to be made of solid gold, but King Hiero for some reason +suspected the honesty of the jeweller, and desired to know if +Archimedes could devise a way of testing the question without +injuring the crown. Greek imagination seldom spoiled a story in +the telling, and in this case the tale was allowed to take on the +most picturesque of phases. The philosopher, we are assured, +pondered the problem for a long time without succeeding, but one +day as he stepped into a bath, his attention was attracted by the +overflow of water. A new train of ideas was started in his +ever-receptive brain. Wild with enthusiasm he sprang from the +bath, and, forgetting his robe, dashed along the streets of +Syracuse, shouting: "Eureka! Eureka!" (I have found it!) The +thought that had come into his mind was this: That any heavy +substance must have a bulk proportionate to its weight; that gold +and silver differ in weight, bulk for bulk, and that the way to +test the bulk of such an irregular object as a crown was to +immerse it in water. The experiment was made. A lump of pure gold +of the weight of the crown was immersed in a certain receptacle +filled with water, and the overflow noted. Then a lump of pure +silver of the same weight was similarly immersed; lastly the +crown itself was immersed, and of course--for the story must not +lack its dramatic sequel--was found bulkier than its weight of +pure gold. Thus the genius that could balk warriors and armies +could also foil the wiles of the silversmith. + +Whatever the truth of this picturesque narrative, the fact +remains that some, such experiments as these must have paved the +way for perhaps the greatest of all the studies of +Archimedes--those that relate to the buoyancy of water. Leaving +the field of fable, we must now examine these with some +precision. Fortunately, the writings of Archimedes himself are +still extant, in which the results of his remarkable experiments +are related, so we may present the results in the words of the +discoverer. + +Here they are: "First: The surface of every coherent liquid in a +state of rest is spherical, and the centre of the sphere +coincides with the centre of the earth. Second: A solid body +which, bulk for bulk, is of the same weight as a liquid, if +immersed in the liquid will sink so that the surface of the body +is even with the surface of the liquid, but will not sink deeper. +Third: Any solid body which is lighter, bulk for bulk, than a +liquid, if placed in the liquid will sink so deep as to displace +the mass of liquid equal in weight to another body. Fourth: If a +body which is lighter than a liquid is forcibly immersed in the +liquid, it will be pressed upward with a force corresponding to +the weight of a like volume of water, less the weight of the body +itself. Fifth: Solid bodies which, bulk for bulk, are heavier +than a liquid, when immersed in the liquid sink to the bottom, +but become in the liquid as much lighter as the weight of the +displaced water itself differs from the weight of the solid." +These propositions are not difficult to demonstrate, once they +are conceived, but their discovery, combined with the discovery +of the laws of statics already referred to, may justly be +considered as proving Archimedes the most inventive experimenter +of antiquity. + +Curiously enough, the discovery which Archimedes himself is said +to have considered the most important of all his innovations is +one that seems much less striking. It is the answer to the +question, What is the relation in bulk between a sphere and its +circumscribing cylinder? Archimedes finds that the ratio is +simply two to three. We are not informed as to how he reached his +conclusion, but an obvious method would be to immerse a ball in a +cylindrical cup. The experiment is one which any one can make for +himself, with approximate accuracy, with the aid of a tumbler and +a solid rubber ball or a billiard-ball of just the right size. +Another geometrical problem which Archimedes solved was the +problem as to the size of a triangle which has equal area with a +circle; the answer being, a triangle having for its base the +circumference of the circle and for its altitude the radius. +Archimedes solved also the problem of the relation of the +diameter of the circle to its circumference; his answer being a +close approximation to the familiar 3.1416, which every tyro in +geometry will recall as the equivalent of pi. + +Numerous other of the studies of Archimedes having reference to +conic sections, properties of curves and spirals, and the like, +are too technical to be detailed here. The extent of his +mathematical knowledge, however, is suggested by the fact that he +computed in great detail the number of grains of sand that would +be required to cover the sphere of the sun's orbit, making +certain hypothetical assumptions as to the size of the earth and +the distance of the sun for the purposes of argument. +Mathematicians find his computation peculiarly interesting +because it evidences a crude conception of the idea of +logarithms. From our present stand-point, the paper in which this +calculation is contained has considerable interest because of its +assumptions as to celestial mechanics. Thus Archimedes starts out +with the preliminary assumption that the circumference of the +earth is less than three million stadia. It must be understood +that this assumption is purely for the sake of argument. +Archimedes expressly states that he takes this number because it +is "ten times as large as the earth has been supposed to be by +certain investigators." Here, perhaps, the reference is to +Eratosthenes, whose measurement of the earth we shall have +occasion to revert to in a moment. Continuing, Archimedes asserts +that the sun is larger than the earth, and the earth larger than +the moon. In this assumption, he says, he is following the +opinion of the majority of astronomers. In the third place, +Archimedes assumes that the diameter of the sun is not more than +thirty times greater than that of the moon. Here he is probably +basing his argument upon another set of measurements of +Aristarchus, to which, also, we shall presently refer more at +length. In reality, his assumption is very far from the truth, +since the actual diameter of the sun, as we now know, is +something like four hundred times that of the moon. Fourth, the +circumference of the sun is greater than one side of the +thousand- faced figure inscribed in its orbit. The measurement, +it is expressly stated, is based on the measurements of +Aristarchus, who makes the diameter of the sun 1/170 of its +orbit. Archimedes adds, however, that he himself has measured the +angle and that it appears to him to be less than 1/164, and +greater than 1/200 part of the orbit. That is to say, reduced to +modern terminology, he places the limit of the sun's apparent +size between thirty-three minutes and twenty-seven minutes of +arc. As the real diameter is thirty-two minutes, this calculation +is surprisingly exact, considering the implements then at +command. But the honor of first making it must be given to +Aristarchus and not to Archimedes. + +We need not follow Archimedes to the limits of his +incomprehensible numbers of sand-grains. The calculation is +chiefly remarkable because it was made before the introduction of +the so-called Arabic numerals had simplified mathematical +calculations. It will be recalled that the Greeks used letters +for numerals, and, having no cipher, they soon found themselves +in difficulties when large numbers were involved. The Roman +system of numerals simplified the matter somewhat, but the +beautiful simplicity of the decimal system did not come into +vogue until the Middle Ages, as we shall see. Notwithstanding the +difficulties, however, Archimedes followed out his calculations +to the piling up of bewildering numbers, which the modern +mathematician finds to be the consistent outcome of the problem +he had set himself. + +But it remains to notice the most interesting feature of this +document in which the calculation of the sand- grains is +contained. "It was known to me," says Archimedes, "that most +astronomers understand by the expression 'world' (universe) a +ball of which the centre is the middle point of the earth, and of +which the radius is a straight line between the centre of the +earth and the sun." Archimedes himself appears to accept this +opinion of the majority,--it at least serves as well as the +contrary hypothesis for the purpose of his calculation,--but he +goes on to say: "Aristarchus of Samos, in his writing against the +astronomers, seeks to establish the fact that the world is really +very different from this. He holds the opinion that the fixed +stars and the sun are immovable and that the earth revolves in a +circular line about the sun, the sun being at the centre of this +circle." This remarkable bit of testimony establishes beyond +question the position of Aristarchus of Samos as the Copernicus +of antiquity. We must make further inquiry as to the teachings of +the man who had gained such a remarkable insight into the true +system of the heavens. + + +ARISTARCHUS OF SAMOS, THE COPERNICUS OF ANTIQUITY + +It appears that Aristarchus was a contemporary of Archimedes, but +the exact dates of his life are not known. He was actively +engaged in making astronomical observations in Samos somewhat +before the middle of the third century B.C.; in other words, just +at the time when the activities of the Alexandrian school were at +their height. Hipparchus, at a later day, was enabled to compare +his own observations with those made by Aristarchus, and, as we +have just seen, his work was well known to so distant a +contemporary as Archimedes. Yet the facts of his life are almost +a blank for us, and of his writings only a single one has been +preserved. That one, however, is a most important and interesting +paper on the measurements of the sun and the moon. Unfortunately, +this paper gives us no direct clew as to the opinions of +Aristarchus concerning the relative positions of the earth and +sun. But the testimony of Archimedes as to this is unequivocal, +and this testimony is supported by other rumors in themselves +less authoritative. + +In contemplating this astronomer of Samos, then, we are in the +presence of a man who had solved in its essentials the problem of +the mechanism of the solar system. It appears from the words of +Archimedes that Aristarchus; had propounded his theory in +explicit writings. Unquestionably, then, he held to it as a +positive doctrine, not as a mere vague guess. We shall show, in a +moment, on what grounds he based his opinion. Had his teaching +found vogue, the story of science would be very different from +what it is. We should then have no tale to tell of a Copernicus +coming upon the scene fully seventeen hundred years later with +the revolutionary doctrine that our world is not the centre of +the universe. We should not have to tell of the persecution of a +Bruno or of a Galileo for teaching this doctrine in the +seventeenth century of an era which did not begin till two +hundred years after the death of Aristarchus. But, as we know, +the teaching of the astronomer of Samos did not win its way. The +old conservative geocentric doctrine, seemingly so much more in +accordance with the every-day observations of mankind, supported +by the majority of astronomers with the Peripatetic philosophers +at their head, held its place. It found fresh supporters +presently among the later Alexandrians, and so fully eclipsed the +heliocentric view that we should scarcely know that view had even +found an advocate were it not for here and there such a chance +record as the phrases we have just quoted from Archimedes. Yet, +as we now see, the heliocentric doctrine, which we know to be +true, had been thought out and advocated as the correct theory of +celestial mechanics by at least one worker of the third century +B.C. Such an idea, we may be sure, did not spring into the mind +of its originator except as the culmination of a long series of +observations and inferences. The precise character of the +evolution we perhaps cannot trace, but its broader outlines are +open to our observation, and we may not leave so important a +topic without at least briefly noting them. + +Fully to understand the theory of Aristarchus, we must go back a +century or two and recall that as long ago as the time of that +other great native of Samos, Pythagoras, the conception had been +reached that the earth is in motion. We saw, in dealing with +Pythagoras, that we could not be sure as to precisely what he +himself taught, but there is no question that the idea of the +world's motion became from an early day a so-called Pythagorean +doctrine. While all the other philosophers, so far as we know, +still believed that the world was flat, the Pythagoreans out in +Italy taught that the world is a sphere and that the apparent +motions of the heavenly bodies are really due to the actual +motion of the earth itself. They did not, however, vault to the +conclusion that this true motion of the earth takes place in the +form of a circuit about the sun. Instead of that, they conceived +the central body of the universe to be a great fire, invisible +from the earth, because the inhabited side of the terrestrial +ball was turned away from it. The sun, it was held, is but a +great mirror, which reflects the light from the central fire. Sun +and earth alike revolve about this great fire, each in its own +orbit. Between the earth and the central fire there was, +curiously enough, supposed to be an invisible earthlike body +which was given the name of Anticthon, or counter-earth. This +body, itself revolving about the central fire, was supposed to +shut off the central light now and again from the sun or from the +moon, and thus to account for certain eclipses for which the +shadow of the earth did not seem responsible. It was, perhaps, +largely to account for such eclipses that the counter-earth was +invented. But it is supposed that there was another reason. The +Pythagoreans held that there is a peculiar sacredness in the +number ten. Just as the Babylonians of the early day and the +Hegelian philosophers of a more recent epoch saw a sacred +connection between the number seven and the number of planetary +bodies, so the Pythagoreans thought that the universe must be +arranged in accordance with the number ten. Their count of the +heavenly bodies, including the sphere of the fixed stars, seemed +to show nine, and the counter-earth supplied the missing body. + +The precise genesis and development of this idea cannot now be +followed, but that it was prevalent about the fifth century B.C. +as a Pythagorean doctrine cannot be questioned. Anaxagoras also +is said to have taken account of the hypothetical counter-earth +in his explanation of eclipses; though, as we have seen, he +probably did not accept that part of the doctrine which held the +earth to be a sphere. The names of Philolaus and Heraclides have +been linked with certain of these Pythagorean doctrines. Eudoxus, +too, who, like the others, lived in Asia Minor in the fourth +century B.C., was held to have made special studies of the +heavenly spheres and perhaps to have taught that the earth moves. +So, too, Nicetas must be named among those whom rumor credited +with having taught that the world is in motion. In a word, the +evidence, so far as we can garner it from the remaining +fragments, tends to show that all along, from the time of the +early Pythagoreans, there had been an undercurrent of opinion in +the philosophical world which questioned the fixity of the earth; +and it would seem that the school of thinkers who tended to +accept the revolutionary view centred in Asia Minor, not far from +the early home of the founder of the Pythagorean doctrines. It +was not strange, then, that the man who was finally to carry +these new opinions to their logical conclusion should hail from +Samos. + +But what was the support which observation could give to this +new, strange conception that the heavenly bodies do not in +reality move as they seem to move, but that their apparent motion +is due to the actual revolution of the earth? It is extremely +difficult for any one nowadays to put himself in a mental +position to answer this question. We are so accustomed to +conceive the solar system as we know it to be, that we are wont +to forget how very different it is from what it seems. Yet one +needs but to glance up at the sky, and then to glance about one +at the solid earth, to grant, on a moment's reflection, that the +geocentric idea is of all others the most natural; and that to +conceive the sun as the actual Centre of the solar system is an +idea which must look for support to some other evidence than that +which ordinary observation can give. Such was the view of most of +the ancient philosophers, and such continued to be the opinion of +the majority of mankind long after the time of Copernicus. We +must not forget that even so great an observing astronomer as +Tycho Brahe, so late as the seventeenth century, declined to +accept the heliocentric theory, though admitting that all the +planets except the earth revolve about the sun. We shall see that +before the Alexandrian school lost its influence a geocentric +scheme had been evolved which fully explained all the apparent +motions of the heavenly bodies. All this, then, makes us but +wonder the more that the genius of an Aristarchus could give +precedence to scientific induction as against the seemingly clear +evidence of the senses. + +What, then, was the line of scientific induction that led +Aristarchus to this wonderful goal? Fortunately, we are able to +answer that query, at least in part. Aristarchus gained his +evidence through some wonderful measurements. First, he measured +the disks of the sun and the moon. This, of course, could in +itself give him no clew to the distance of these bodies, and +therefore no clew as to their relative size; but in attempting to +obtain such a clew he hit upon a wonderful yet altogether simple +experiment. It occurred to him that when the moon is precisely +dichotomized-- that is to say, precisely at the half-the line of +vision from the earth to the moon must be precisely at right +angles with the line of light passing from the sun to the moon. +At this moment, then, the imaginary lines joining the sun, the +moon, and the earth, make a right angle triangle. But the +properties of the right-angle triangle had long been studied and +were well under stood. One acute angle of such a triangle +determines the figure of the triangle itself. We have already +seen that Thales, the very earliest of the Greek philosophers, +measured the distance of a ship at sea by the application of this +principle. Now Aristarchus sights the sun in place of Thales' +ship, and, sighting the moon at the same time, measures the angle +and establishes the shape of his right-angle triangle. This does +not tell him the distance of the sun, to be sure, for he does not +know the length of his base-line--that is to say, of the line +between the moon and the earth. But it does establish the +relation of that base-line to the other lines of the triangle; in +other words, it tells him the distance of the sun in terms of the +moon's distance. As Aristarchus strikes the angle, it shows that +the sun is eighteen times as distant as the moon. Now, by +comparing the apparent size of the sun with the apparent size of +the moon--which, as we have seen, Aristarchus has already +measured--he is able to tell us that, the sun is "more than 5832 +times, and less than 8000" times larger than the moon; though his +measurements, taken by themselves, give no clew to the actual +bulk of either body. These conclusions, be it understood, are +absolutely valid inferences--nay, demonstrations--from the +measurements involved, provided only that these measurements have +been correct. Unfortunately, the angle of the triangle we have +just seen measured is exceedingly difficult to determine with +accuracy, while at the same time, as a moment's reflection will +show, it is so large an angle that a very slight deviation from +the truth will greatly affect the distance at which its line +joins the other side of the triangle. Then again, it is virtually +impossible to tell the precise moment when the moon is at half, +as the line it gives is not so sharp that we can fix it with +absolute accuracy. There is, moreover, another element of error +due to the refraction of light by the earth's atmosphere. The +experiment was probably made when the sun was near the horizon, +at which time, as we now know, but as Aristarchus probably did +not suspect, the apparent displacement of the sun's position is +considerable; and this displacement, it will be observed, is in +the direction to lessen the angle in question. + +In point of fact, Aristarchus estimated the angle at eighty-seven +degrees. Had his instrument been more precise, and had he been +able to take account of all the elements of error, he would have +found it eighty-seven degrees and fifty-two minutes. The +difference of measurement seems slight; but it sufficed to make +the computations differ absurdly from the truth. The sun is +really not merely eighteen times but more than two hundred times +the distance of the moon, as Wendelein discovered on repeating +the experiment of Aristarchus about two thousand years later. Yet +this discrepancy does not in the least take away from the +validity of the method which Aristarchus employed. Moreover, his +conclusion, stated in general terms, was perfectly correct: the +sun is many times more distant than the moon and vastly larger +than that body. Granted, then, that the moon is, as Aristarchus +correctly believed, considerably less in size than the earth, the +sun must be enormously larger than the earth; and this is the +vital inference which, more than any other, must have seemed to +Aristarchus to confirm the suspicion that the sun and not the +earth is the centre of the planetary system. It seemed to him +inherently improbable that an enormously large body like the sun +should revolve about a small one such as the earth. And again, it +seemed inconceivable that a body so distant as the sun should +whirl through space so rapidly as to make the circuit of its +orbit in twenty- four hours. But, on the other hand, that a small +body like the earth should revolve about the gigantic sun seemed +inherently probable. This proposition granted, the rotation of +the earth on its axis follows as a necessary consequence in +explanation of the seeming motion of the stars. Here, then, was +the heliocentric doctrine reduced to a virtual demonstration by +Aristarchus of Samos, somewhere about the middle of the third +century B.C. + +It must be understood that in following out the, steps of +reasoning by which we suppose Aristarchus to have reached so +remarkable a conclusion, we have to some extent guessed at the +processes of thought- development; for no line of explication +written by the astronomer himself on this particular point has +come down to us. There does exist, however, as we have already +stated, a very remarkable treatise by Aristarchus on the Size and +Distance of the Sun and the Moon, which so clearly suggests the +methods of reasoning of the great astronomer, and so explicitly +cites the results of his measurements, that we cannot well pass +it by without quoting from it at some length. It is certainly one +of the most remarkable scientific documents of antiquity. As +already noted, the heliocentric doctrine is not expressly stated +here. It seems to be tacitly implied throughout, but it is not a +necessary consequence of any of the propositions expressly +stated. These propositions have to do with certain observations +and measurements and what Aristarchus believes to be inevitable +deductions from them, and he perhaps did not wish to have these +deductions challenged through associating them with a theory +which his contemporaries did not accept. In a word, the paper of +Aristarchus is a rigidly scientific document unvitiated by +association with any theorizings that are not directly germane to +its central theme. The treatise opens with certain hypotheses as +follows: + +"First. The moon receives its light from the sun. + +"Second. The earth may be considered as a point and as the centre +of the orbit of the moon. + +"Third. When the moon appears to us dichotomized it offers to our +view a great circle [or actual meridian] of its circumference +which divides the illuminated part from the dark part. + +"Fourth. When the moon appears dichotomized its distance from the +sun is less than a quarter of the circumference [of its orbit] by +a thirtieth part of that quarter." + +That is to say, in modern terminology, the moon at this time +lacks three degrees (one thirtieth of ninety degrees) of being at +right angles with the line of the sun as viewed from the earth; +or, stated otherwise, the angular distance of the moon from the +sun as viewed from the earth is at this time eighty-seven +degrees--this being, as we have already observed, the fundamental +measurement upon which so much depends. We may fairly suppose +that some previous paper of Aristarchus's has detailed the +measurement which here is taken for granted, yet which of course +could depend solely on observation. + +"Fifth. The diameter of the shadow [cast by the earth at the +point where the moon's orbit cuts that shadow when the moon is +eclipsed] is double the diameter of the moon." + +Here again a knowledge of previously established measurements is +taken for granted; but, indeed, this is the case throughout the +treatise. + +"Sixth. The arc subtended in the sky by the moon is a fifteenth +part of a sign" of the zodiac; that is to say, since there are +twenty-four, signs in the zodiac, one-fifteenth of one +twenty-fourth, or in modern terminology, one degree of arc. This +is Aristarchus's measurement of the moon to which we have already +referred when speaking of the measurements of Archimedes. + +"If we admit these six hypotheses," Aristarchus continues, "it +follows that the sun is more than eighteen times more distant +from the earth than is the moon, and that it is less than twenty +times more distant, and that the diameter of the sun bears a +corresponding relation to the diameter of the moon; which is +proved by the position of the moon when dichotomized. But the +ratio of the diameter of the sun to that of the earth is greater +than nineteen to three and less than forty-three to six. This is +demonstrated by the relation of the distances, by the position +[of the moon] in relation to the earth's shadow, and by the fact +that the arc subtended by the moon is a fifteenth part of a +sign." + +Aristarchus follows with nineteen propositions intended to +elucidate his hypotheses and to demonstrate his various +contentions. These show a singularly clear grasp of geometrical +problems and an altogether correct conception of the general +relations as to size and position of the earth, the moon, and the +sun. His reasoning has to do largely with the shadow cast by the +earth and by the moon, and it presupposes a considerable +knowledge of the phenomena of eclipses. His first proposition is +that "two equal spheres may always be circumscribed in a +cylinder; two unequal spheres in a cone of which the apex is +found on the side of the smaller sphere; and a straight line +joining the centres of these spheres is perpendicular to each of +the two circles made by the contact of the surface of the +cylinder or of the cone with the spheres." + +It will be observed that Aristarchus has in mind here the moon, +the earth, and the sun as spheres to be circumscribed within a +cone, which cone is made tangible and measurable by the shadows +cast by the non-luminous bodies; since, continuing, he clearly +states in proposition nine, that "when the sun is totally +eclipsed, an observer on the earth's surface is at an apex of a +cone comprising the moon and the sun." Various propositions deal +with other relations of the shadows which need not detain us +since they are not fundamentally important, and we may pass to +the final conclusions of Aristarchus, as reached in his +propositions ten to nineteen. + +Now, since (proposition ten) "the diameter of the sun is more +than eighteen times and less than twenty times greater than that +of the moon," it follows (proposition eleven) "that the bulk of +the sun is to that of the moon in ratio, greater than 5832 to 1, +and less than 8000 to 1." + +"Proposition sixteen. The diameter of the sun is to the diameter +of the earth in greater proportion than nineteen to three, and +less than forty-three to six. + +"Proposition seventeen. The bulk of the sun is to that of the +earth in greater proportion than 6859 to 27, and less than 79,507 +to 216. + +"Proposition eighteen. The diameter of the earth is to the +diameter of the moon in greater proportion than 108 to 43 and +less than 60 to 19. + +"Proposition nineteen. The bulk of the earth is to that of the +moon in greater proportion than 1,259,712 to 79,507 and less than +20,000 to 6859." + +Such then are the more important conclusions of this very +remarkable paper--a paper which seems to have interest to the +successors of Aristarchus generation after generation, since this +alone of all the writings of the great astronomer has been +preserved. How widely the exact results of the measurements of +Aristarchus, differ from the truth, we have pointed out as we +progressed. But let it be repeated that this detracts little from +the credit of the astronomer who had such clear and correct +conceptions of the relations of the heavenly bodies and who +invented such correct methods of measurement. Let it be +particularly observed, however, that all the conclusions of +Aristarchus are stated in relative terms. He nowhere attempts to +estimate the precise size of the earth, of the moon, or of the +sun, or the actual distance of one of these bodies from another. +The obvious reason for this is that no data were at hand from +which to make such precise measurements. Had Aristarchus known +the size of any one of the bodies in question, he might readily, +of course, have determined the size of the others by the mere +application of his relative scale; but he had no means of +determining the size of the earth, and to this extent his system +of measurements remained imperfect. Where Aristarchus halted, +however, another worker of the same period took the task in hand +and by an altogether wonderful measurement determined the size of +the earth, and thus brought the scientific theories of cosmology +to their climax. This worthy supplementor of the work of +Aristarchus was Eratosthenes of Alexandria. + + +ERATOSTHENES, "THE SURVEYOR OF THE WORLD" + +An altogether remarkable man was this native of Cyrene, who came +to Alexandria from Athens to be the chief librarian of Ptolemy +Euergetes. He was not merely an astronomer and a geographer, but +a poet and grammarian as well. His contemporaries jestingly +called him Beta the Second, because he was said through the +universality of his attainments to be "a second Plato" in +philosophy, "a second Thales" in astronomy, and so on throughout +the list. He was also called the "surveyor of the world," in +recognition of his services to geography. Hipparchus said of him, +perhaps half jestingly, that he had studied astronomy as a +geographer and geography as an astronomer. It is not quite clear +whether the epigram was meant as compliment or as criticism. +Similar phrases have been turned against men of versatile talent +in every age. Be that as it may, Eratosthenes passed into history +as the father of scientific geography and of scientific +chronology; as the astronomer who first measured the obliquity of +the ecliptic; and as the inventive genius who performed the +astounding feat of measuring the size of the globe on which we +live at a time when only a relatively small portion of that +globe's surface was known to civilized man. It is no discredit to +approach astronomy as a geographer and geography as an +astronomer if the results are such as these. What +Eratosthenes really did was to approach both astronomy and +geography from two seemingly divergent points of attack--namely, +from the stand-point of the geometer and also from that of the +poet. Perhaps no man in any age has brought a better combination +of observing and imaginative faculties to the aid of science. + +Nearly all the discoveries of Eratosthenes are associated with +observations of the shadows cast by the sun. We have seen that, +in the study of the heavenly bodies, much depends on the +measurement of angles. Now the easiest way in which angles can be +measured, when solar angles are in question, is to pay attention, +not to the sun itself, but to the shadow that it casts. We saw +that Thales made some remarkable measurements with the aid of +shadows, and we have more than once referred to the gnomon, which +is the most primitive, but which long remained the most +important, of astronomical instruments. It is believed that +Eratosthenes invented an important modification of the gnomon +which was elaborated afterwards by Hipparchus and called an +armillary sphere. This consists essentially of a small gnomon, or +perpendicular post, attached to a plane representing the earth's +equator and a hemisphere in imitation of the earth's surface. +With the aid of this, the shadow cast by the sun could be very +accurately measured. It involves no new principle. Every +perpendicular post or object of any kind placed in the sunlight +casts a shadow from which the angles now in question could be +roughly measured. The province of the armillary sphere was to +make these measurements extremely accurate. + +With the aid of this implement, Eratosthenes carefully noted the +longest and the shortest shadows cast by the gnomon--that is to +say, the shadows cast on the days of the solstices. He found that +the distance between the tropics thus measured represented 47 +degrees 42' 39" of arc. One-half of this, or 23 degrees 5,' +19.5", represented the obliquity of the ecliptic--that is to say, +the angle by which the earth's axis dipped from the perpendicular +with reference to its orbit. This was a most important +observation, and because of its accuracy it has served modern +astronomers well for comparison in measuring the trifling change +due to our earth's slow, swinging wobble. For the earth, be it +understood, like a great top spinning through space, holds its +position with relative but not quite absolute fixity. It must not +be supposed, however, that the experiment in question was quite +new with Eratosthenes. His merit consists rather in the accuracy +with which he made his observation than in the novelty of the +conception; for it is recorded that Eudoxus, a full century +earlier, had remarked the obliquity of the ecliptic. That +observer had said that the obliquity corresponded to the side of +a pentadecagon, or fifteen-sided figure, which is equivalent in +modern phraseology to twenty- four degrees of arc. But so little +is known regarding the way in which Eudoxus reached his estimate +that the measurement of Eratosthenes is usually spoken of as if +it were the first effort of the kind. + +Much more striking, at least in its appeal to the popular +imagination, was that other great feat which Eratosthenes +performed with the aid of his perfected gnomon--the measurement +of the earth itself. When we reflect that at this period the +portion of the earth open to observation extended only from the +Straits of Gibraltar on the west to India on the east, and from +the North Sea to Upper Egypt, it certainly seems enigmatical--at +first thought almost miraculous--that an observer should have +been able to measure the entire globe. That he should have +accomplished this through observation of nothing more than a tiny +bit of Egyptian territory and a glimpse of the sun's shadow makes +it seem but the more wonderful. Yet the method of Eratosthenes, +like many another enigma, seems simple enough once it is +explained. It required but the application of a very elementary +knowledge of the geometry of circles, combined with the use of a +fact or two from local geography--which detracts nothing from the +genius of the man who could reason from such simple premises to +so wonderful a conclusion. + +Stated in a few words, the experiment of Eratosthenes was this. +His geographical studies had taught him that the town of Syene +lay directly south of Alexandria, or, as we should say, on the +same meridian of latitude. He had learned, further, that Syene +lay directly under the tropic, since it was reported that at noon +on the day of the summer solstice the gnomon there cast no +shadow, while a deep well was illumined to the bottom by the sun. +A third item of knowledge, supplied by the surveyors of Ptolemy, +made the distance between Syene and Alexandria five thousand +stadia. These, then, were the preliminary data required by +Eratosthenes. Their significance consists in the fact that here +is a measured bit of the earth's arc five thousand stadia in +length. If we could find out what angle that bit of arc subtends, +a mere matter of multiplication would give us the size of the +earth. But how determine this all-important number? The answer +came through reflection on the relations of concentric circles. +If you draw any number of circles, of whatever size, about a +given centre, a pair of radii drawn from that centre will cut +arcs of the same relative size from all the circles. One circle +may be so small that the actual arc subtended by the radii in a +given case may be but an inch in length, while another circle is +so large that its corresponding are is measured in millions of +miles; but in each case the same number of so-called degrees will +represent the relation of each arc to its circumference. Now, +Eratosthenes knew, as just stated, that the sun, when on the +meridian on the day of the summer solstice, was directly over the +town of Syene. This meant that at that moment a radius of the +earth projected from Syene would point directly towards the sun. +Meanwhile, of course, the zenith would represent the projection +of the radius of the earth passing through Alexandria. All that +was required, then, was to measure, at Alexandria, the angular +distance of the sun from the zenith at noon on the day of the +solstice to secure an approximate measurement of the arc of the +sun's circumference, corresponding to the arc of the earth's +surface represented by the measured distance between Alexandria +and Syene. + +The reader will observe that the measurement could not be +absolutely accurate, because it is made from the surface of the +earth, and not from the earth's centre, but the size of the earth +is so insignificant in comparison with the distance of the sun +that this slight discrepancy could be disregarded. + +The way in which Eratosthenes measured this angle was very +simple. He merely measured the angle of the shadow which his +perpendicular gnomon at Alexandria cast at mid-day on the day of +the solstice, when, as already noted, the sun was directly +perpendicular at Syene. Now a glance at the diagram will make it +clear that the measurement of this angle of the shadow is merely +a convenient means of determining the precisely equal opposite +angle subtending an arc of an imaginary circle passing through +the sun; the are which, as already explained, corresponds with +the arc of the earth's surface represented by the distance +between Alexandria and Syene. He found this angle to represent 7 +degrees 12', or one-fiftieth of the circle. Five thousand stadia, +then, represent one-fiftieth of the earth's circumference; the +entire circumference being, therefore, 250,000 stadia. +Unfortunately, we do not know which one of the various +measurements used in antiquity is represented by the stadia of +Eratosthenes. According to the researches of Lepsius, however, +the stadium in question represented 180 meters, and this would +make the earth, according to the measurement of Eratosthenes, +about twenty-eight thousand miles in circumference, an answer +sufficiently exact to justify the wonder which the experiment +excited in antiquity, and the admiration with which it has ever +since been regarded. + +{illustration caption = DIAGRAM TO ILLUSTRATE ERATOSTHENES' +MEASUREMENT OF THE GLOBE + +FIG. 1. AF is a gnomon at Alexandria; SB a gnomon at Svene; IS +and JK represent the sun's rays. The angle actually measured by +Eratosthenes is KFA, as determined by the shadow cast by the +gnomon AF. This angle is equal to the opposite angle JFL, which +measures the sun's distance from the zenith; and which is also +equal to the angle AES--to determine the Size of which is the +real object of the entire measurement. + +FIG. 2 shows the form of the gnomon actually employed in +antiquity. The hemisphere KA being marked with a scale, it is +obvious that in actual practice Eratosthenes required only to set +his gnomon in the sunlight at the proper moment, and read off the +answer to his problem at a glance. The simplicity of the method +makes the result seem all the more wonderful.} + +Of course it is the method, and not its details or its exact +results, that excites our interest. And beyond question the +method was an admirable one. Its result, however, could not have +been absolutely accurate, because, while correct in principle, +its data were defective. In point of fact Syene did not lie +precisely on the same meridian as Alexandria, neither did it lie +exactly on the tropic. Here, then, are two elements of +inaccuracy. Moreover, it is doubtful whether Eratosthenes made +allowance, as he should have done, for the semi-diameter of the +sun in measuring the angle of the shadow. But these are mere +details, scarcely worthy of mention from our present stand-point. +What perhaps is deserving of more attention is the fact that this +epoch-making measurement of Eratosthenes may not have been the +first one to be made. A passage of Aristotle records that the +size of the earth was said to be 400,000 stadia. Some +commentators have thought that Aristotle merely referred to the +area of the inhabited portion of the earth and not to the +circumference of the earth itself, but his words seem doubtfully +susceptible of this interpretation; and if he meant, as his words +seem to imply, that philosophers of his day had a tolerably +precise idea of the globe, we must assume that this idea was +based upon some sort of measurement. The recorded size, 400,000 +stadia, is a sufficient approximation to the truth to suggest +something more than a mere unsupported guess. Now, since +Aristotle died more than fifty years before Eratosthenes was +born, his report as to the alleged size of the earth certainly +has a suggestiveness that cannot be overlooked; but it arouses +speculations without giving an inkling as to their solution. If +Eratosthenes had a precursor as an earth-measurer, no hint or +rumor has come down to us that would enable us to guess who that +precursor may have been. His personality is as deeply enveloped +in the mists of the past as are the personalities of the great +prehistoric discoverers. For the purpose of the historian, +Eratosthenes must stand as the inventor of the method with which +his name is associated, and as the first man of whom we can say +with certainty that he measured the size of the earth. Right +worthily, then, had the Alexandrian philosopher won his proud +title of "surveyor of the world." + + +HIPPARCHUS, "THE LOVER OF TRUTH" + +Eratosthenes outlived most of his great contemporaries. He saw +the turning of that first and greatest century of Alexandrian +science, the third century before our era. He died in the year +196 B.C., having, it is said, starved himself to death to escape +the miseries of blindness;--to the measurer of shadows, life +without light seemed not worth the living. Eratosthenes left no +immediate successor. A generation later, however, another great +figure appeared in the astronomical world in the person of +Hipparchus, a man who, as a technical observer, had perhaps no +peer in the ancient world: one who set so high a value upon +accuracy of observation as to earn the title of "the lover of +truth." Hipparchus was born at Nicaea, in Bithynia, in the year +160 B.C. His life, all too short for the interests of science, +ended in the year 125 B.C. The observations of the great +astronomer were made chiefly, perhaps entirely, at Rhodes. A +misinterpretation of Ptolemy's writings led to the idea that +Hipparchus, performed his chief labors in Alexandria, but it is +now admitted that there is no evidence for this. Delambre +doubted, and most subsequent writers follow him here, whether +Hipparchus ever so much as visited Alexandria. In any event there +seems to be no question that Rhodes may claim the honor of being +the chief site of his activities. + +It was Hipparchus whose somewhat equivocal comment on the work of +Eratosthenes we have already noted. No counter-charge in kind +could be made against the critic himself; he was an astronomer +pure and simple. His gift was the gift of accurate observation +rather than the gift of imagination. No scientific progress is +possible without scientific guessing, but Hipparchus belonged to +that class of observers with whom hypothesis is held rigidly +subservient to fact. It was not to be expected that his mind +would be attracted by the heliocentric theory of Aristarchus. He +used the facts and observations gathered by his great predecessor +of Samos, but he declined to accept his theories. For him the +world was central; his problem was to explain, if he could, the +irregularities of motion which sun, moon, and planets showed in +their seeming circuits about the earth. Hipparchus had the gnomon +of Eratosthenes--doubtless in a perfected form--to aid him, and +he soon proved himself a master in its use. For him, as we have +said, accuracy was everything; this was the one element that led +to all his great successes. + +Perhaps his greatest feat was to demonstrate the eccentricity of +the sun's seeming orbit. We of to-day, thanks to Keppler and his +followers, know that the earth and the other planetary bodies in +their circuit about the sun describe an ellipse and not a circle. +But in the day of Hipparchus, though the ellipse was recognized +as a geometrical figure (it had been described and named along +with the parabola and hyperbola by Apollonius of Perga, the pupil +of Euclid), yet it would have been the rankest heresy to suggest +an elliptical course for any heavenly body. A metaphysical +theory, as propounded perhaps by the Pythagoreans but ardently +supported by Aristotle, declared that the circle is the perfect +figure, and pronounced it inconceivable that the motions of the +spheres should be other than circular. This thought dominated the +mind of Hipparchus, and so when his careful measurements led him +to the discovery that the northward and southward journeyings of +the sun did not divide the year into four equal parts, there was +nothing open to him but to either assume that the earth does not +lie precisely at the centre of the sun's circular orbit or to +find some alternative hypothesis. + +In point of fact, the sun (reversing the point of view in +accordance with modern discoveries) does lie at one focus of the +earth's elliptical orbit, and therefore away from the physical +centre of that orbit; in other words, the observations of +Hipparchus were absolutely accurate. He was quite correct in +finding that the sun spends more time on one side of the equator +than on the other. When, therefore, he estimated the relative +distance of the earth from the geometrical centre of the sun's +supposed circular orbit, and spoke of this as the measure of the +sun's eccentricity, he propounded a theory in which true data of +observation were curiously mingled with a positively inverted +theory. That the theory of Hipparchus was absolutely consistent +with all the facts of this particular observation is the best +evidence that could be given of the difficulties that stood in +the way of a true explanation of the mechanism of the heavens. + +But it is not merely the sun which was observed to vary in the +speed of its orbital progress; the moon and the planets also show +curious accelerations and retardations of motion. The moon in +particular received most careful attention from Hipparchus. +Dominated by his conception of the perfect spheres, he could find +but one explanation of the anomalous motions which he observed, +and this was to assume that the various heavenly bodies do not +fly on in an unvarying arc in their circuit about the earth, but +describe minor circles as they go which can be likened to nothing +so tangibly as to a light attached to the rim of a wagon-wheel in +motion. If such an invisible wheel be imagined as carrying the +sun, for example, on its rim, while its invisible hub follows +unswervingly the circle of the sun's mean orbit (this wheel, be +it understood, lying in the plane of the orbit, not at right- +angles to it), then it must be obvious that while the hub remains +always at the same distance from the earth, the circling rim will +carry the sun nearer the earth, then farther away, and that while +it is traversing that portion of the are which brings it towards +the earth, the actual forward progress of the sun will be +retarded notwithstanding the uniform motion of the hub, just as +it will be accelerated in the opposite arc. Now, if we suppose +our sun-bearing wheel to turn so slowly that the sun revolves but +once about its imaginary hub while the wheel itself is making the +entire circuit of the orbit, we shall have accounted for the +observed fact that the sun passes more quickly through one-half +of the orbit than through the other. Moreover, if we can +visualize the process and imagine the sun to have left a visible +line of fire behind him throughout the course, we shall see that +in reality the two circular motions involved have really resulted +in producing an elliptical orbit. + +The idea is perhaps made clearer if we picture the actual +progress of the lantern attached to the rim of an ordinary +cart-wheel. When the cart is drawn forward the lantern is made to +revolve in a circle as regards the hub of the wheel, but since +that hub is constantly going forward, the actual path described +by the lantern is not a circle at all but a waving line. It is +precisely the same with the imagined course of the sun in its +orbit, only that we view these lines just as we should view the +lantern on the wheel if we looked at it from directly above and +not from the side. The proof that the sun is describing this +waving line, and therefore must be considered as attached to an +imaginary wheel, is furnished, as it seemed to Hipparchus, by the +observed fact of the sun's varying speed. + +That is one way of looking at the matter. It is an hypothesis +that explains the observed facts--after a fashion, and indeed a +very remarkable fashion. The idea of such an explanation did not +originate with Hipparchus. The germs of the thought were as old +as the Pythagorean doctrine that the earth revolves about a +centre that we cannot see. Eudoxus gave the conception greater +tangibility, and may be considered as the father of this doctrine +of wheels--epicycles, as they came to be called. Two centuries +before the time of Hipparchus he conceived a doctrine of spheres +which Aristotle found most interesting, and which served to +explain, along the lines we have just followed, the observed +motions of the heavenly bodies. Calippus, the reformer of the +calendar, is said to have carried an account of this theory to +Aristotle. As new irregularities of motion of the sun, moon, and +planetary bodies were pointed out, new epicycles were invented. +There is no limit to the number of imaginary circles that may be +inscribed about an imaginary centre, and if we conceive each one +of these circles to have a proper motion of its own, and each one +to carry the sun in the line of that motion, except as it is +diverted by the other motions--if we can visualize this complex +mingling of wheels--we shall certainly be able to imagine the +heavenly body which lies at the juncture of all the rims, as +being carried forward in as erratic and wobbly a manner as could +be desired. In other words, the theory of epicycles will account +for all the facts of the observed motions of all the heavenly +bodies, but in so doing it fills the universe with a most +bewildering network of intersecting circles. Even in the time of +Calippus fifty-five of these spheres were computed. + +We may well believe that the clear-seeing Aristarchus would look +askance at such a complex system of imaginary machinery. But +Hipparchus, pre-eminently an observer rather than a theorizer, +seems to have been content to accept the theory of epicycles as +he found it, though his studies added to its complexities; and +Hipparchus was the dominant scientific personality of his +century. What he believed became as a law to his immediate +successors. His tenets were accepted as final by their great +popularizer, Ptolemy, three centuries later; and so the +heliocentric theory of Aristarchus passed under a cloud almost at +the hour of its dawning, there to remain obscured and forgotten +for the long lapse of centuries. A thousand pities that the +greatest observing astronomer of antiquity could not, like one of +his great precursors, have approached astronomy from the +stand-point of geography and poetry. Had he done so, perhaps he +might have reflected, like Aristarchus before him, that it seems +absurd for our earth to hold the giant sun in thraldom; then +perhaps his imagination would have reached out to the +heliocentric doctrine, and the cobweb hypothesis of epicycles, +with that yet more intangible figment of the perfect circle, +might have been wiped away. + +But it was not to be. With Aristarchus the scientific imagination +had reached its highest flight; but with Hipparchus it was +beginning to settle back into regions of foggier atmosphere and +narrower horizons. For what, after all, does it matter that +Hipparchus should go on to measure the precise length of the year +and the apparent size of the moon's disk; that he should make a +chart of the heavens showing the place of 1080 stars; even that +he should discover the precession of the equinox;--what, after +all, is the significance of these details as against the +all-essential fact that the greatest scientific authority of his +century--the one truly heroic scientific figure of his +epoch--should have lent all the forces of his commanding +influence to the old, false theory of cosmology, when the true +theory had been propounded and when he, perhaps, was the only man +in the world who might have substantiated and vitalized that +theory? It is easy to overestimate the influence of any single +man, and, contrariwise, to underestimate the power of the +Zeitgeist. But when we reflect that the doctrines of Hipparchus, +as promulgated by Ptolemy, became, as it were, the last word of +astronomical science for both the Eastern and Western worlds, and +so continued after a thousand years, it is perhaps not too much +to say that Hipparchus, "the lover of truth," missed one of the +greatest opportunities for the promulgation of truth ever +vouchsafed to a devotee of pure science. + +But all this, of course, detracts nothing from the merits of +Hipparchus as an observing astronomer. A few words more must be +said as to his specific discoveries in this field. According to +his measurement, the tropic year consists of 365 days, 5 hours, +and 49 minutes, varying thus only 12 seconds from the true year, +as the modern astronomer estimates it. Yet more remarkable, +because of the greater difficulties involved, was Hipparchus's +attempt to measure the actual distance of the moon. Aristarchus +had made a similar attempt before him. Hipparchus based his +computations on studies of the moon in eclipse, and he reached +the conclusion that the distance of the moon is equal to 59 radii +of the earth (in reality it is 60.27 radii). Here, then, was the +measure of the base-line of that famous triangle with which +Aristarchus had measured the distance of the sun. Hipparchus must +have known of that measurement, since he quotes the work of +Aristarchus in other fields. Had he now but repeated the +experiment of Aristarchus, with his perfected instruments and his +perhaps greater observational skill, he was in position to +compute the actual distance of the sun in terms not merely of the +moon's distance but of the earth's radius. And now there was the +experiment of Eratosthenes to give the length of that radius in +precise terms. In other words, Hipparchus might have measured the +distance of the sun in stadia. But if he had made the +attempt--and, indeed, it is more than likely that he did so--the +elements of error in his measurements would still have kept him +wide of the true figures. + +The chief studies of Hipparchus were directed, as we have seen, +towards the sun and the moon, but a phenomenon that occurred in +the year 134 B.C. led him for a time to give more particular +attention to the fixed stars. The phenomenon in question was the +sudden outburst of a new star; a phenomenon which has been +repeated now and again, but which is sufficiently rare and +sufficiently mysterious to have excited the unusual attention of +astronomers in all generations. Modern science offers an +explanation of the phenomenon, as we shall see in due course. We +do not know that Hipparchus attempted to explain it, but he was +led to make a chart of the heavens, probably with the idea of +guiding future observers in the observation of new stars. Here +again Hipparchus was not altogether an innovator, since a chart +showing the brightest stars had been made by Eratosthenes; but +the new charts were much elaborated. + +The studies of Hipparchus led him to observe the stars chiefly +with reference to the meridian rather than with reference to +their rising, as had hitherto been the custom. In making these +studies of the relative position of the stars, Hipparchus was led +to compare his observations with those of the Babylonians, which, +it was said, Alexander had caused to be transmitted to Greece. He +made use also of the observations of Aristarchus and others of +his Greek precursors. The result of his comparisons proved that +the sphere of the fixed stars had apparently shifted its position +in reference to the plane of the sun's orbit--that is to say, the +plane of the ecliptic no longer seemed to cut the sphere of the +fixed stars at precisely the point where the two coincided in +former centuries. The plane of the ecliptic must therefore be +conceived as slowly revolving in such a way as gradually to +circumnavigate the heavens. This important phenomenon is +described as the precession of the equinoxes. + +It is much in question whether this phenomenon was not known to +the ancient Egyptian astronomers; but in any event, Hipparchus is +to be credited with demonstrating the fact and making it known to +the Western world. A further service was rendered theoretical +astronomy by Hipparchus through his invention of the planosphere, +an instrument for the representation of the mechanism of the +heavens. His computations of the properties of the spheres led +him also to what was virtually a discovery of the method of +trigonometry, giving him, therefore, a high position in the field +of mathematics. All in all, then, Hipparchus is a most heroic +figure. He may well be considered the greatest star-gazer of +antiquity, though he cannot, without injustice to his great +precursors, be allowed the title which is sometimes given him of +"father of systematic astronomy." + + +CTESIBIUS AND HERO: MAGICIANS OF ALEXANDRIA + +Just about the time when Hipparchus was working out at Rhodes his +puzzles of celestial mechanics, there was a man in Alexandria who +was exercising a strangely inventive genius over mechanical +problems of another sort; a man who, following the example set by +Archimedes a century before, was studying the problems of matter +and putting his studies to practical application through the +invention of weird devices. The man's name was Ctesibius. We know +scarcely more of him than that he lived in Alexandria, probably +in the first half of the second century B.C. His antecedents, the +place and exact time of his birth and death, are quite unknown. +Neither are we quite certain as to the precise range of his +studies or the exact number of his discoveries. It appears that +he had a pupil named Hero, whose personality, unfortunately, is +scarcely less obscure than that of his master, but who wrote a +book through which the record of the master's inventions was +preserved to posterity. Hero, indeed, wrote several books, though +only one of them has been preserved. The ones that are lost bear +the following suggestive titles: On the Construction of Slings; +On the Construction of Missiles; On the Automaton; On the Method +of Lifting Heavy Bodies; On the Dioptric or Spying-tube. The work +that remains is called Pneumatics, and so interesting a work it +is as to make us doubly regret the loss of its companion volumes. +Had these other books been preserved we should doubtless have a +clearer insight than is now possible into some at least of the +mechanical problems that exercised the minds of the ancient +philosophers. The book that remains is chiefly concerned, as its +name implies, with the study of gases, or, rather, with the study +of a single gas, this being, of course, the air. But it tells us +also of certain studies in the dynamics of water that are most +interesting, and for the historian of science most important. + +Unfortunately, the pupil of Ctesibius, whatever his ingenuity, +was a man with a deficient sense of the ethics of science. He +tells us in his preface that the object of his book is to record +some ingenious discoveries of others, together with additional +discoveries of his own, but nowhere in the book itself does he +give us the, slightest clew as to where the line is drawn between +the old and the new. Once, in discussing the weight of water, he +mentions the law of Archimedes regarding a floating body, but +this is the only case in which a scientific principle is traced +to its source or in which credit is given to any one for a +discovery. This is the more to be regretted because Hero has +discussed at some length the theories involved in the treatment +of his subject. This reticence on the part of Hero, combined with +the fact that such somewhat later writers as Pliny and Vitruvius +do not mention Hero's name, while they frequently mention the +name of his master, Ctesibius, has led modern critics to a +somewhat sceptical attitude regarding the position of Hero as an +actual discoverer. + +The man who would coolly appropriate some discoveries of others +under cloak of a mere prefatorial reference was perhaps an +expounder rather than an innovator, and had, it is shrewdly +suspected, not much of his own to offer. Meanwhile, it is +tolerably certain that Ctesibius was the discoverer of the +principle of the siphon, of the forcing-pump, and of a pneumatic +organ. An examination of Hero's book will show that these are +really the chief principles involved in most of the various +interesting mechanisms which he describes. We are constrained, +then, to believe that the inventive genius who was really +responsible for the mechanisms we are about to describe was +Ctesibius, the master. Yet we owe a debt of gratitude to Hero, +the pupil, for having given wider vogue to these discoveries, and +in particular for the discussion of the principles of +hydrostatics and pneumatics contained in the introduction to his +book. This discussion furnishes us almost our only knowledge as +to the progress of Greek philosophers in the field of mechanics +since the time of Archimedes. + +The main purpose of Hero in his preliminary thesis has to do with +the nature of matter, and recalls, therefore, the studies of +Anaxagoras and Democritus. Hero, however, approaches his subject +from a purely material or practical stand-point. He is an +explicit champion of what we nowadays call the molecular theory +of matter. "Every body," he tells us, "is composed of minute +particles, between which are empty spaces less than these +particles of the body. It is, therefore, erroneous to say that +there is no vacuum except by the application of force, and that +every space is full either of air or water or some other +substance. But in proportion as any one of these particles +recedes, some other follows it and fills the vacant space; +therefore there is no continuous vacuum, except by the +application of some force [like suction]--that is to say, an +absolute vacuum is never found, except as it is produced +artificially." Hero brings forward some thoroughly convincing +proofs of the thesis he is maintaining. "If there were no void +places between the particles of water," he says, "the rays of +light could not penetrate the water; moreover, another liquid, +such as wine, could not spread itself through the water, as it is +observed to do, were the particles of water absolutely +continuous." The latter illustration is one the validity of which +appeals as forcibly to the physicists of to-day as it did to +Hero. The same is true of the argument drawn from the +compressibility of gases. Hero has evidently made a careful study +of this subject. He knows that an inverted tube full of air may +be immersed in water without becoming wet on the inside, proving +that air is a physical substance; but he knows also that this +same air may be caused to expand to a much greater bulk by the +application of heat, or may, on the other hand, be condensed by +pressure, in which case, as he is well aware, the air exerts +force in the attempt to regain its normal bulk. But, he argues, +surely we are not to believe that the particles of air expand to +fill all the space when the bulk of air as a whole expands under +the influence of heat; nor can we conceive that the particles of +normal air are in actual contact, else we should not be able to +compress the air. Hence his conclusion, which, as we have seen, +he makes general in its application to all matter, that there are +spaces, or, as he calls them, vacua, between the particles that +go to make up all substances, whether liquid, solid, or gaseous. + +Here, clearly enough, was the idea of the "atomic" nature of +matter accepted as a fundamental notion. The argumentative +attitude assumed by Hero shows that the doctrine could not be +expected to go unchallenged. But, on the other hand, there is +nothing in his phrasing to suggest an intention to claim +originality for any phase of the doctrine. We may infer that in +the three hundred years that had elapsed since the time of +Anaxagoras, that philosopher's idea of the molecular nature of +matter had gained fairly wide currency. As to the expansive power +of gas, which Hero describes at some length without giving us a +clew to his authorities, we may assume that Ctesibius was an +original worker, yet the general facts involved were doubtless +much older than his day. Hero, for example, tells us of the +cupping-glass used by physicians, which he says is made into a +vacuum by burning up the air in it; but this apparatus had +probably been long in use, and Hero mentions it not in order to +describe the ordinary cupping-glass which is referred to, but a +modification of it. He refers to the old form as if it were +something familiar to all. + +Again, we know that Empedocles studied the pressure of the air in +the fifth century B.C., and discovered that it would support a +column of water in a closed tube, so this phase of the subject is +not new. But there is no hint anywhere before this work of Hero +of a clear understanding that the expansive properties of the air +when compressed, or when heated, may be made available as a motor +power. Hero, however, has the clearest notions on the subject and +puts them to the practical test of experiment. Thus he constructs +numerous mechanisms in which the expansive power of air under +pressure is made to do work, and others in which the same end is +accomplished through the expansive power of heated air. For +example, the doors of a temple are made to swing open +automatically when a fire is lighted on a distant altar, closing +again when the fire dies out--effects which must have filled the +minds of the pious observers with bewilderment and wonder, +serving a most useful purpose for the priests, who alone, we may +assume, were in the secret. There were two methods by which this +apparatus was worked. In one the heated air pressed on the water +in a close retort connected with the altar, forcing water out of +the retort into a bucket, which by its weight applied a force +through pulleys and ropes that turned the standards on which the +temple doors revolved. When the fire died down the air +contracted, the water was siphoned back from the bucket, which, +being thus lightened, let the doors close again through the +action of an ordinary weight. The other method was a slight +modification, in which the retort of water was dispensed with and +a leather sack like a large football substitued. The ropes +and pulleys were connected with this sack, which exerted a pull +when the hot air expanded, and which collapsed and thus relaxed +its strain when the air cooled. A glance at the illustrations +taken from Hero's book will make the details clear. + +Other mechanisms utilized a somewhat different combination of +weights, pulleys, and siphons, operated by the expansive power of +air, unheated but under pressure, such pressure being applied +with a force- pump, or by the weight of water running into a +closed receptacle. One such mechanism gives us a constant jet of +water or perpetual fountain. Another curious application of the +principle furnishes us with an elaborate toy, consisting of a +group of birds which alternately whistle or are silent, while an +owl seated on a neighboring perch turns towards the birds when +their song begins and away from them when it ends. The "singing" +of the birds, it must be explained, is produced by the expulsion +of air through tiny tubes passing up through their throats from a +tank below. The owl is made to turn by a mechanism similar to +that which manipulates the temple doors. The pressure is supplied +merely by a stream of running water, and the periodical silence +of the birds is due to the fact that this pressure is relieved +through the automatic siphoning off of the water when it reaches +a certain height. The action of the siphon, it may be added, is +correctly explained by Hero as due to the greater weight of the +water in the longer arm of the bent tube. As before mentioned, +the siphon is repeatedly used in these mechanisms of Hero. The +diagram will make clear the exact application of it in the +present most ingenious mechanism. We may add that the principle +of the whistle was a favorite one of Hero. By the aid of a +similar mechanism he brought about the blowing of trumpets when +the temple doors were opened, a phenomenon which must greatly +have enhanced the mystification. It is possible that this +principle was utilized also in connection with statues to produce +seemingly supernatural effects. This may be the explanation of +the tradition of the speaking statue in the temple of Ammon at +Thebes. + +{illustration caption = DEVICE FOR CAUSING THE DOORS OF THE +TEMPLE TO OPEN WHEN THE FIRE ON THE ALTAR IS LIGHTED (Air heated +in the altar F drives water from the closed receptacle H through +the tube KL into the bucket M, which descends through gravity, +thus opening the doors. When the altar cools, the air contracts, +the water is sucked from the bucket, and the weight and pulley +close the doors.)} + +{illustration caption = THE STEAM-ENGINE OF HERO (The steam +generated in the receptacle AB passes through the tube EF into +the globe, and escapes through the bent tubes H and K, causing +the globe to rotate on the axis LG.)} + + +The utilization of the properties of compressed air was not +confined, however, exclusively to mere toys, or to produce +miraculous effects. The same principle was applied to a practical +fire-engine, worked by levers and force-pumps; an apparatus, in +short, altogether similar to that still in use in rural +districts. A slightly different application of the motive power +of expanding air is furnished in a very curious toy called "the +dancing figures." In this, air heated in a retort like a +miniature altar is allowed to escape through the sides of two +pairs of revolving arms precisely like those of the ordinary +revolving fountain with which we are accustomed to water our +lawns, the revolving arms being attached to a plane on which +several pairs of statuettes representing dancers are placed, An +even more interesting application of this principle of setting a +wheel in motion is furnished in a mechanism which must be +considered the earliest of steam-engines. Here, as the name +implies, the gas supplying the motive power is actually steam. +The apparatus made to revolve is a globe connected with the +steam-retort by a tube which serves as one of its axes, the steam +escaping from the globe through two bent tubes placed at either +end of an equatorial diameter. It does not appear that Hero had +any thought of making practical use of this steam- engine. It was +merely a curious toy--nothing more. Yet had not the age that +succeeded that of Hero been one in which inventive genius was +dormant, some one must soon have hit upon the idea that this +steam- engine might be improved and made to serve a useful +purpose. As the case stands, however, there was no advance made +upon the steam motor of Hero for almost two thousand years. And, +indeed, when the practical application of steam was made, towards +the close of the eighteenth century, it was made probably quite +without reference to the experiment of Hero, though knowledge of +his toy may perhaps have given a clew to Watt or his +predecessors. + + +{illustration caption = THE SLOT-MACHINE OF HERO (The coin +introduced at A falls on the lever R, and by its weight opens the +valve S, permitting the liquid to escape through the invisible +tube LM. As the lever tips, the coin slides off and the valve +closes. The liquid in tank must of course be kept above F.)} + +In recent times there has been a tendency to give to this +steam-engine of Hero something more than full meed of +appreciation. To be sure, it marked a most important principle in +the conception that steam might be used as a motive power, but, +except in the demonstration of this principle, the mechanism of +Hero was much too primitive to be of any importance. But there is +one mechanism described by Hero which was a most explicit +anticipation of a device, which presumably soon went out of use, +and which was not reinvented until towards the close of the +nineteenth century. This was a device which has become familiar +in recent times as the penny-in-the-slot machine. When towards +the close of the nineteenth century some inventive craftsman hit +upon the idea of an automatic machine to supply candy, a box of +cigarettes, or a whiff of perfumery, he may or may not have +borrowed his idea from the slot-machine of Hero; but in any +event, instead of being an innovator he was really two thousand +years behind the times, for the slot-machine of Hero is the +precise prototype of these modern ones. + +The particular function which the mechanism of Hero was destined +to fulfil was the distribution of a jet of water, presumably used +for sacramental purposes, which was given out automatically when +a five- drachma coin was dropped into the slot at the top of the +machine. The internal mechanism of the machine was simple enough, +consisting merely of a lever operating a valve which was opened +by the weight of the coin dropping on the little shelf at the end +of the lever, and which closed again when the coin slid off the +shelf. The illustration will show how simple this mechanism was. +Yet to the worshippers, who probably had entered the temple +through doors miraculously opened, and who now witnessed this +seemingly intelligent response of a machine, the result must have +seemed mystifying enough; and, indeed, for us also, when we +consider how relatively crude was the mechanical knowledge of the +time, this must seem nothing less than marvellous. As in +imagination we walk up to the sacred tank, drop our drachma in +the slot, and hold our hand for the spurt of holy-water, can we +realize that this is the land of the Pharaohs, not England or +America; that the kingdom of the Ptolemies is still at its +height; that the republic of Rome is mistress of the world; that +all Europe north of the Alps is inhabited solely by barbarians; +that Cleopatra and Julius Caesar are yet unborn; that the +Christian era has not yet begun? Truly, it seems as if there +could be no new thing under the sun. + + + +X. SCIENCE OF THE ROMAN PERIOD + +We have seen that the third century B.C. was a time when +Alexandrian science was at its height, but that the second +century produced also in Hipparchus at least one investigator of +the very first rank; though, to be sure, Hipparchus can be called +an Alexandrian only by courtesy. In the ensuing generations the +Greek capital at the mouth of the Nile continued to hold its +place as the centre of scientific and philosophical thought. The +kingdom of the Ptolemies still flourished with at least the +outward appearances of its old-time glory, and a company of +grammarians and commentators of no small merit could always be +found in the service of the famous museum and library; but the +whole aspect of world-history was rapidly changing. Greece, after +her brief day of political supremacy, was sinking rapidly +into desuetude, and the hard-headed Roman in the West was making +himself master everywhere. While Hipparchus of Rhodes was in his +prime, Corinth, the last stronghold of the main-land of Greece, +had fallen before the prowess of the Roman, and the kingdom of +the Ptolemies, though still nominally free, had begun to come +within the sphere of Roman influence. + +Just what share these political changes had in changing the +aspect of Greek thought is a question regarding which difference +of opinion might easily prevail; but there can be no question +that, for one reason or another, the Alexandrian school as a +creative centre went into a rapid decline at about the time of +the Roman rise to world-power. There are some distinguished +names, but, as a general rule, the spirit of the times is +reminiscent rather than creative; the workers tend to collate the +researches of their predecessors rather than to make new and +original researches for themselves. Eratosthenes, the inventive +world-measurer, was succeeded by Strabo, the industrious collator +of facts; Aristarchus and Hipparchus, the originators of new +astronomical methods, were succeeded by Ptolemy, the perfecter of +their methods and the systematizer of their knowledge. Meanwhile, +in the West, Rome never became a true culture-centre. The great +genius of the Roman was political; the Augustan Age produced a +few great historians and poets, but not a single great +philosopher or creative devotee of science. Cicero, Lucian, +Seneca, Marcus Aurelius, give us at best a reflection of Greek +philosophy. Pliny, the one world-famous name in the scientific +annals of Rome, can lay claim to no higher credit than that of a +marvellously industrious collector of facts--the compiler of an +encyclopaedia which contains not one creative touch. + +All in all, then, this epoch of Roman domination is one that need +detain the historian of science but a brief moment. With the +culmination of Greek effort in the so-called Hellenistic period +we have seen ancient science at its climax. The Roman period is +but a time of transition, marking, as it were, a plateau on the +slope between those earlier heights and the deep, dark valleys of +the Middle Ages. Yet we cannot quite disregard the efforts of +such workers as those we have just named. Let us take a more +specific glance at their accomplishments. + + +STRABO THE GEOGRAPHER + +The earliest of these workers in point of time is Strabo. This +most famous of ancient geographers was born in Amasia, Pontus, +about 63 B.C., and lived to the year 24 A.D., living, therefore, +in the age of Caesar and Augustus, during which the final +transformation in the political position of the kingdom of Egypt +was effected. The name of Strabo in a modified form has become +popularized through a curious circumstance. The geographer, it +appears, was afflicted with a peculiar squint of the eyes, hence +the name strabismus, which the modern oculist applies to that +particular infirmity. + +Fortunately, the great geographer has not been forced to depend +upon hearsay evidence for recognition. His comprehensive work on +geography has been preserved in its entirety, being one of the +few expansive classical writings of which this is true. The other +writings of Strabo, however, including certain histories of which +reports have come down to us, are entirely lost. The geography is +in many ways a remarkable book. It is not, however, a work in +which any important new principles are involved. Rather is it +typical of its age in that it is an elaborate compilation and a +critical review of the labors of Strabo's predecessors. Doubtless +it contains a vast deal of new information as to the details of +geography--precise areas and distance, questions of geographical +locations as to latitude and zones, and the like. But however +important these details may have been from a contemporary +stand-point, they, of course, can have nothing more than +historical interest to posterity. The value of the work from our +present stand-point is chiefly due to the criticisms which Strabo +passes upon his forerunners, and to the incidental historical and +scientific references with which his work abounds. Being written +in this closing period of ancient progress, and summarizing, as +it does, in full detail the geographical knowledge of the time, +it serves as an important guide-mark for the student of the +progress of scientific thought. We cannot do better than briefly +to follow Strabo in his estimates and criticisms of the work of +his predecessors, taking note thus of the point of view from +which he himself looked out upon the world. We shall thus gain a +clear idea as to the state of scientific geography towards the +close of the classical epoch. + +"If the scientific investigation of any subject be the proper +avocation of the philosopher," says Strabo, "geography, the +science of which we propose to treat, is certainly entitled to a +high place; and this is evident from many considerations. They +who first undertook to handle the matter were distinguished men. +Homer, Anaximander the Milesian, and Hecaeus (his fellow-citizen +according to Eratosthenes), Democritus, Eudoxus, Dicaearchus, and +Ephorus, with many others, and after these, Eratosthenes, +Polybius, and Posidonius, all of them philosophers. Nor is the +great learning through which alone this subject can be approached +possessed by any but a person acquainted with both human and +divine things, and these attainments constitute what is called +philosophy. In addition to its vast importance in regard to +social life and the art of government, geography unfolds to us a +celestial phenomena, acquaints us with the occupants of the land +and ocean, and the vegetation, fruits, and peculiarities of the +various quarters of the earth, a knowledge of which marks him who +cultivates it as a man earnest in the great problem of life and +happiness." + +Strabo goes on to say that in common with other critics, +including Hipparchus, he regards Homer as the first great +geographer. He has much to say on the geographical knowledge of +the bard, but this need not detain us. We are chiefly concerned +with his comment upon his more recent predecessors, beginning +with Eratosthenes. The constant reference to this worker shows +the important position which he held. Strabo appears neither as +detractor nor as partisan, but as one who earnestly desires the +truth. Sometimes he seems captious in his criticisms regarding +some detail, nor is he always correct in his emendations of the +labors of others; but, on the whole, his work is marked by an +evident attempt at fairness. In reading his book, however, one is +forced to the conclusion that Strabo is an investigator of +details, not an original thinker. He seems more concerned with +precise measurements than with questionings as to the open +problems of his science. Whatever he accepts, then, may be taken +as virtually the stock doctrine of the period. + +"As the size of the earth," he says, "has been demonstrated by +other writers, we shall here take for granted and receive as +accurate what they have advanced. We shall also assume that the +earth is spheroidal, that its surface is likewise spheroidal and, +above all, that bodies have a tendency towards its centre, which +latter point is clear to the perception of the most average +understanding. However, we may show summarily that the earth is +spheroidal, from the consideration that all things, however +distant, tend to its centre, and that every body is attracted +towards its centre by gravity. This is more distinctly proved +from observations of the sea and sky, for here the evidence of +the senses and common observation is alone requisite. The +convexity of the sea is a further proof of this to those who have +sailed, for they cannot perceive lights at a distance when placed +at the same level as their eyes, and if raised on high they at +once become perceptible to vision though at the same time farther +removed. So when the eye is raised it sees what before was +utterly imperceptible. Homer speaks of this when he says: + + +" 'Lifted up on the vast wave he quickly beheld afar.' + +Sailors as they approach their destination behold the shore +continually raising itself to their view, and objects which had +at first seemed low begin to lift themselves. Our gnomons, also, +are, among other things, evidence of the revolution of the +heavenly bodies, and common-sense at once shows us that if the +depth of the earth were infinite such a revolution could not take +place."[1] + +Elsewhere Strabo criticises Eratosthenes for having entered into +a long discussion as to the form of the earth. This matter, +Strabo thinks, "should have been disposed of in the compass of a +few words." Obviously this doctrine of the globe's sphericity +had, in the course of 600 years, become so firmly established +among the Greek thinkers as to seem almost axiomatic. We shall +see later on how the Western world made a curious recession from +this seemingly secure position under stimulus of an Oriental +misconception. As to the size of the globe, Strabo is disposed to +accept without particular comment the measurements of +Eratosthenes. He speaks, however, of "more recent measurements," +referring in particular to that adopted by Posidonius, according +to which the circumference is only about one hundred and eighty +thousand stadia. Posidonius, we may note in passing, was a +contemporary and friend of Cicero, and hence lived shortly before +the time of Strabo. His measurement of the earth was based on +observations of a star which barely rose above the southern +horizon at Rhodes as compared with the height of the same star +when observed at Alexandria. This measurement of Posidonius, +together with the even more famous measurement of Eratosthenes, +appears to have been practically the sole guide as to the size of +the earth throughout the later periods of antiquity, and, indeed, +until the later Middle Ages. + +As becomes a writer who is primarily geographer and historian +rather than astronomer, Strabo shows a much keener interest in +the habitable portions of the globe than in the globe as a whole. +He assures us that this habitable portion of the earth is a great +island, "since wherever men have approached the termination of +the land, the sea, which we designate ocean, has been met with, +and reason assures us of the similarity of this place which our +senses have not been tempted to survey." He points out that +whereas sailors have not circumnavigated the globe, that they had +not been prevented from doing so by any continent, and it seems +to him altogether unlikely that the Atlantic Ocean is divided +into two seas by narrow isthmuses so placed as to prevent +circumnavigation. "How much more probable that it is confluent +and uninterrupted. This theory," he adds, "goes better with the +ebb and flow of the ocean. Moreover (and here his reasoning +becomes more fanciful), the greater the amount of moisture +surrounding the earth, the easier would the heavenly bodies be +supplied with vapor from thence." Yet he is disposed to believe, +following Plato, that the tradition "concerning the island of +Atlantos might be received as something more than idle fiction, +it having been related by Solon, on the authority of the Egyptian +priests, that this island, almost as large as a continent, was +formerly in existence although now it had disappeared."[2] + +In a word, then, Strabo entertains no doubt whatever that it +would be possible to sail around the globe from Spain to India. +Indeed, so matter-of-fact an inference was this that the feat of +Columbus would have seemed less surprising in the first century +of our era than it did when actually performed in the fifteenth +century. The terrors of the great ocean held the mariner back, +rather than any doubt as to where he would arrive at the end of +the voyage. + +Coupled with the idea that the habitable portion of the earth is +an island, there was linked a tolerably definite notion as to the +shape of this island. This shape Strabo likens to a military +cloak. The comparison does not seem peculiarly apt when we are +told presently that the length of the habitable earth is more +than twice its breadth. This idea, Strabo assures us, accords +with the most accurate observations "both ancient and modern." +These observations seemed to show that it is not possible to live +in the region close to the equator, and that, on the other hand, +the cold temperature sharply limits the habitability of the globe +towards the north. All the civilization of antiquity clustered +about the Mediterranean, or extended off towards the east at +about the same latitude. Hence geographers came to think of the +habitable globe as having the somewhat lenticular shape which a +crude map of these regions suggests. We have already had occasion +to see that at an earlier day Anaxagoras was perhaps influenced +in his conception of the shape of the earth by this idea, and the +constant references of Strabo impress upon us the thought that +this long, relatively narrow area of the earth's surface is the +only one which can be conceived of as habitable. + +Strabo had much to tell us concerning zones, which, following +Posidonius, he believes to have been first described by +Parmenides. We may note, however, that other traditions assert +that both Thales and Pythagoras had divided the earth into zones. +The number of zones accepted by Strabo is five, and he +criticises Polybius for making the number six. The five +zones accepted by Strabo are as follows: the uninhabitable torrid +zone lying in the region of the equator; a zone on either side of +this extending to the tropic; and then the temperate zones +extending in either direction from the tropic to the arctic +regions. There seems to have been a good deal of dispute among +the scholars of the time as to the exact arrangement of these +zones, but the general idea that the north-temperate zone is the +part of the earth with which the geographer deals seemed clearly +established. That the south-temperate zone would also present a +habitable area is an idea that is sometimes suggested, though +seldom or never distinctly expressed. It is probable that +different opinions were held as to this, and no direct evidence +being available, a cautiously scientific geographer like Strabo +would naturally avoid the expression of an opinion regarding it. +Indeed, his own words leave us somewhat in doubt as to the +precise character of his notion regarding the zones. Perhaps we +shall do best to quote them: + +"Let the earth be supposed to consist of five zones. (1) The +equatorial circle described around it. (2) Another parallel to +this, and defining the frigid zone of the northern hemisphere. +(3) A circle passing through the poles and cutting the two +preceding circles at right- angles. The northern hemisphere +contains two quarters of the earth, which are bounded by the +equator and circle passing through the poles. Each of these +quarters should be supposed to contain a four-sided district, its +northern side being of one-half of the parallel next the pole, +its southern by the half of the equator, and its remaining sides +by two segments of the circle drawn through the poles, opposite +to each other, and equal in length. In one of these (which of +them is of no consequence) the earth which we inhabit is +situated, surrounded by a sea and similar to an island. This, as +we said before, is evident both to our senses and to our reason. +But let any one doubt this, it makes no difference so far as +geography is concerned whether you believe the portion of the +earth which we inhabit to be an island or only admit what we know +from experience --namely, that whether you start from the east or +the west you may sail all around it. Certain intermediate spaces +may have been left (unexplored), but these are as likely to be +occupied by sea as uninhabited land. The object of the geographer +is to describe known countries. Those which are unknown he passes +over equally with those beyond the limits of the inhabited earth. +It will, therefore, be sufficient for describing the contour of +the island we have been speaking of, if we join by a right line +the outmost points which, up to this time, have been explored by +voyagers along the coast on either side."[3] + +We may pass over the specific criticisms of Strabo upon various +explorations that seem to have been of great interest to his +contemporaries, including an alleged trip of one Eudoxus out into +the Atlantic, and the journeyings of Pytheas in the far north. It +is Pytheas, we may add, who was cited by Hipparchus as having +made the mistaken observation that the length of the shadow of +the gnomon is the same at Marseilles and Byzantium, hence that +these two places are on the same parallel. Modern commentators +have defended Pytheas as regards this observation, claiming that +it was Hipparchus and not Pytheas who made the second observation +from which the faulty induction was drawn. The point is of no +great significance, however, except as showing that a correct +method of determining the problems of latitude had thus early +been suggested. That faulty observations and faulty application +of the correct principle should have been made is not surprising. +Neither need we concern ourselves with the details as to the +geographical distances, which Strabo found so worthy of criticism +and controversy. But in leaving the great geographer we may +emphasize his point of view and that of his contemporaries by +quoting three fundamental principles which he reiterates as being +among the "facts established by natural philosophers." He tells +us that "(1) The earth and heavens are spheroidal. (2) The +tendency of all bodies having weight is towards a centre. (3) +Further, the earth being spheroidal and having the same centre as +the heavens, is motionless, as well as the axis that passes +through both it and the heavens. The heavens turn round both the +earth and its axis, from east to west. The fixed stars turn round +with it at the same rate as the whole. These fixed stars follow +in their course parallel circles, the principal of which are the +equator, two tropics, and the arctic circles; while the planets, +the sun, and the moon describe certain circles comprehended +within the zodiac."[4] + +Here, then, is a curious mingling of truth and error. The +Pythagorean doctrine that the earth is round had become a +commonplace, but it would appear that the theory of Aristarchus, +according to which the earth is in motion, has been almost +absolutely forgotten. Strabo does not so much as refer to it; +neither, as we shall see, is it treated with greater respect by +the other writers of the period. + + +TWO FAMOUS EXPOSITORS--PLINY AND PTOLEMY + +While Strabo was pursuing his geographical studies at Alexandria, +a young man came to Rome who was destined to make his name more +widely known in scientific annals than that of any other Latin +writer of antiquity. This man was Plinius Secundus, who, to +distinguish him from his nephew, a famous writer in another +field, is usually spoken of as Pliny the Elder. There is a famous +story to the effect that the great Roman historian Livy on one +occasion addressed a casual associate in the amphitheatre at +Rome, and on learning that the stranger hailed from the outlying +Spanish province of the empire, remarked to him, "Yet you have +doubtless heard of my writings even there." "Then," replied the +stranger, "you must be either Livy or Pliny." + +The anecdote illustrates the wide fame which the Roman naturalist +achieved in his own day. And the records of the Middle Ages show +that this popularity did not abate in succeeding times. Indeed, +the Natural History of Pliny is one of the comparatively few +bulky writings of antiquity that the efforts of copyists have +preserved to us almost entire. It is, indeed, a remarkable work +and eminently typical of its time; but its author was an +industrious compiler, not a creative genius. As a monument of +industry it has seldom been equalled, and in this regard it seems +the more remarkable inasmuch as Pliny was a practical man of +affairs who occupied most of his life as a soldier fighting the +battles of the empire. He compiled his book in the leisure hours +stolen from sleep, often writing by the light of the camp-fire. +Yet he cites or quotes from about four thousand works, most of +which are known to us only by his references. Doubtless Pliny +added much through his own observations. We know how keen was his +desire to investigate, since he lost his life through attempting +to approach the crater of Vesuvius on the occasion of that +memorable eruption which buried the cities of Herculaneum and +Pompeii. + +Doubtless the wandering life of the soldier had given Pliny +abundant opportunity for personal observation in his favorite +fields of botany and zoology. But the records of his own +observations are so intermingled with knowledge drawn from books +that it is difficult to distinguish the one from the other. Nor +does this greatly matter, for whether as closet-student or +field-naturalist, Pliny's trait of mind is essentially that of +the compiler. He was no philosophical thinker, no generalizer, no +path-maker in science. He lived at the close of a great +progressive epoch of thought; in one of those static periods when +numberless observers piled up an immense mass of details which +might advantageously be sorted into a kind of encyclopaedia. Such +an encyclopaedia is the so-called Natural History of Pliny. It is +a vast jumble of more or less uncritical statements regarding +almost every field of contemporary knowledge. The descriptions of +animals and plants predominate, but the work as a whole would +have been immensely improved had the compiler shown a more +critical spirit. As it is, he seems rather disposed to quote any +interesting citation that he comes across in his omnivorous +readings, shielding himself behind an equivocal "it is said," or +"so and so alleges." A single illustration will suffice to show +what manner of thing is thought worthy of repetition. + +"It is asserted," he says, "that if the fish called a sea-star is +smeared with the fox's blood and then nailed to the upper lintel +of the door, or to the door itself, with a copper nail, no +noxious spell will be able to obtain admittance, or, at all +events, be productive of any ill effects." + +It is easily comprehensible that a work fortified with such +practical details as this should have gained wide popularity. +Doubtless the natural histories of our own day would find readier +sale were they to pander to various superstitions not altogether +different from that here suggested. The man, for example, who +believes that to have a black cat cross his path is a lucky omen +would naturally find himself attracted by a book which took +account of this and similar important details of natural history. +Perhaps, therefore, it was its inclusion of absurdities, quite as +much as its legitimate value, that gave vogue to the celebrated +work of Pliny. But be that as it may, the most famous scientist +of Rome must be remembered as a popular writer rather than as an +experimental worker. In the history of the promulgation of +scientific knowledge his work is important; in the history of +scientific principles it may virtually be disregarded. + + +PTOLEMY, THE LAST GREAT ASTRONOMER OF ANTIQUITY + +Almost the same thing may be said of Ptolemy, an even more +celebrated writer, who was born not very long after the death of +Pliny. The exact dates of Ptolemy's life are not known, but his +recorded observations extend to the year 151 A.D. He was a +working astronomer, and he made at least one original discovery +of some significance--namely, the observation of a hitherto +unrecorded irregularity of the moon's motion, which came to be +spoken of as the moon's evection. This consists of periodical +aberrations from the moon's regular motion in its orbit, which, +as we now know, are due to the gravitation pull of the sun, but +which remained unexplained until the time of Newton. Ptolemy also +made original observations as to the motions of the planets. He +is, therefore, entitled to a respectable place as an observing +astronomer; but his chief fame rests on his writings. + +His great works have to do with geography and astronomy. In the +former field he makes an advance upon Strabo, citing the latitude +of no fewer than five thousand places. In the field of astronomy, +his great service was to have made known to the world the labors +of Hipparchus. Ptolemy has been accused of taking the star-chart +of his great predecessor without due credit, and indeed it seems +difficult to clear him of this charge. Yet it is at least open to +doubt whether be intended any impropriety, inasmuch as be all +along is sedulous in his references to his predecessor. Indeed, +his work might almost be called an exposition of the astronomical +doctrines of Hipparchus. No one pretends that Ptolemy is to be +compared with the Rhodesian observer as an original investigator, +but as a popular expounder his superiority is evidenced in the +fact that the writings of Ptolemy became practically the sole +astronomical text-book of the Middle Ages both in the East and in +the West, while the writings of Hipparchus were allowed to +perish. + +The most noted of all the writings of Ptolemy is the work which +became famous under the Arabic name of Almagest. This word is +curiously derived from the Greek title <gr h megisth suntazis>, +"the greatest construction," a name given the book to distinguish +it from a work on astrology in four books by the same author. For +convenience of reference it came to be spoken of merely as <gr h +megisth>, from which the Arabs form the title Tabair al Magisthi, +under which title the book was published in the year 827. From +this it derived the word Almagest, by which Ptolemy's work +continued to be known among the Arabs, and subsequently among +Europeans when the book again became known in the West. Ptolemy's +book, as has been said, is virtually an elaboration of the +doctrines of Hipparchus. It assumes that the earth is the fixed +centre of the solar system, and that the stars and planets +revolve about it in twenty-four hours, the earth being, of +course, spherical. It was not to be expected that Ptolemy should +have adopted the heliocentric idea of Aristarchus. Yet it is much +to be regretted that he failed to do so, since the deference +which was accorded his authority throughout the Middle Ages would +doubtless have been extended in some measure at least to this +theory as well, had he championed it. Contrariwise, his +unqualified acceptance of the geocentric doctrine sufficed to +place that doctrine beyond the range of challenge. + +The Almagest treats of all manner of astronomical problems, but +the feature of it which gained it widest celebrity was perhaps +that which has to do with eccentrics and epicycles. This theory +was, of course, but an elaboration of the ideas of Hipparchus; +but, owing to the celebrity of the expositor, it has come to be +spoken of as the theory of Ptolemy. We have sufficiently detailed +the theory in speaking of Hipparchus. It should be explained, +however, that, with both Hipparchus and Ptolemy, the theory of +epicycles would appear to have been held rather as a working +hypothesis than as a certainty, so far as the actuality of the +minor spheres or epicycles is concerned. That is to say, these +astronomers probably did not conceive either the epicycles or the +greater spheres as constituting actual solid substances. +Subsequent generations, however, put this interpretation upon the +theory, conceiving the various spheres as actual crystalline +bodies. It is difficult to imagine just how the various epicycles +were supposed to revolve without interfering with the major +spheres, but perhaps this is no greater difficulty than is +presented by the alleged properties of the ether, which +physicists of to-day accept as at least a working hypothesis. We +shall see later on how firmly the conception of concentric +crystalline spheres was held to, and that no real challenge was +ever given that theory until the discovery was made that comets +have an orbit that must necessarily intersect the spheres of the +various planets. + +Ptolemy's system of geography in eight books, founded on that of +Marinus of Tyre, was scarcely less celebrated throughout the +Middle Ages than the Almagest. It contained little, however, that +need concern us here, being rather an elaboration of the +doctrines to which we have already sufficiently referred. None of +Ptolemy's original manuscripts has come down to us, but there is +an alleged fifth-century manuscript attributed to Agathadamon of +Alexandria which has peculiar interest because it contains a +series of twenty-seven elaborately colored maps that are supposed +to be derived from maps drawn up by Ptolemy himself. In these +maps the sea is colored green, the mountains red or dark yellow, +and the land white. Ptolemy assumed that a degree at the equator +was 500 stadia instead of 604 stadia in length. We are not +informed as to the grounds on which this assumption was made, but +it has been suggested that the error was at least partially +instrumental in leading to one very curious result. "Taking the +parallel of Rhodes," says Donaldson,[5] "he calculated the +longitudes from the Fortunate Islands to Cattigara or the west +coast of Borneo at 180 degrees, conceiving this to be one-half +the circumference of the globe. The real distance is only 125 +degrees or 127 degrees, so that his measurement is wrong by one +third of the whole, one-sixth for the error in the measurement of +a degree and one-sixth for the errors in measuring the distance +geometrically. These errors, owing to the authority attributed to +the geography of Ptolemy in the Middle Ages, produced a +consequence of the greatest importance. They really led to the +discovery of America. For the design of Columbus to sail from the +west of Europe to the east of Asia was founded on the supposition +that the distance was less by one third than it really was." This +view is perhaps a trifle fanciful, since there is nothing to +suggest that the courage of Columbus would have balked at the +greater distance, and since the protests of the sailors, which +nearly thwarted his efforts, were made long before the distance +as estimated by Ptolemy had been covered; nevertheless it is +interesting to recall that the great geographical doctrines, upon +which Columbus must chiefly have based his arguments, had been +before the world in an authoritative form practically unheeded +for more than twelve hundred years, awaiting a champion with +courage enough to put them to the test. + + +GALEN--THE LAST GREAT ALEXANDRIAN + +There is one other field of scientific investigation to which we +must give brief attention before leaving the antique world. This +is the field of physiology and medicine. In considering it we +shall have to do with the very last great scientist of the +Alexandrian school. This was Claudius Galenus, commonly known as +Galen, a man whose fame was destined to eclipse that of all other +physicians of antiquity except Hippocrates, and whose doctrines +were to have the same force in their field throughout the Middle +Ages that the doctrines of Aristotle had for physical science. +But before we take up Galen's specific labors, it will be well to +inquire briefly as to the state of medical art and science in the +Roman world at the time when the last great physician of +antiquity came upon the scene. + +The Romans, it would appear, had done little in the way of +scientific discoveries in the field of medicine, but, +nevertheless, with their practicality of mind, they had turned to +better account many more of the scientific discoveries of the +Greeks than did the discoverers themselves. The practising +physicians in early Rome were mostly men of Greek origin, who +came to the capital after the overthrow of the Greeks by the +Romans. Many of them were slaves, as earning money by either +bodily or mental labor was considered beneath the dignity of a +Roman citizen. The wealthy Romans, who owned large estates and +numerous slaves, were in the habit of purchasing some of these +slave doctors, and thus saving medical fees by having them attend +to the health of their families. + +By the beginning of the Christian era medicine as a profession +had sadly degenerated, and in place of a class of physicians who +practised medicine along rational or legitimate lines, in the +footsteps of the great Hippocrates, there appeared great numbers +of "specialists," most of them charlatans, who pretended to +possess supernatural insight in the methods of treating certain +forms of disease. These physicians rightly earned the contempt of +the better class of Romans, and were made the object of many +attacks by the satirists of the time. Such specialists travelled +about from place to place in much the same manner as the +itinerant "Indian doctors" and "lightning tooth-extractors" do +to-day. Eye-doctors seem to have been particularly numerous, and +these were divided into two classes, eye-surgeons and eye-doctors +proper. The eye-surgeon performed such operations as cauterizing +for ingrowing eyelashes and operating upon growths about the +eyes; while the eye-doctors depended entirely upon salves and +lotions. These eye-salves were frequently stamped with the seal +of the physician who compounded them, something like two hundred +of these seals being still in existence. There were besides these +quacks, however, reputable eye-doctors who must have possessed +considerable skill in the treatment of certain ophthalmias. Among +some Roman surgical instruments discovered at Rheims were found +also some drugs employed by ophthalmic surgeons, and an analysis +of these show that they contained, among other ingredients, some +that are still employed in the treatment of certain affections of +the eye. + +One of the first steps taken in recognition of the services of +physicians was by Julius Caesar, who granted citizenship to all +physicians practising in Rome. This was about fifty years before +the Christian era, and from that time on there was a gradual +improvement in the attitude of the Romans towards the members of +the medical profession. As the Romans degenerated from a race of +sturdy warriors and became more and more depraved physically, the +necessity for physicians made itself more evident. Court +physicians, and physicians-in-ordinary, were created by the +emperors, as were also city and district physicians. In the year +133 A.D. Hadrian granted immunity from taxes and military service +to physicians in recognition of their public services. + +The city and district physicians, known as the archiatri +populaires, treated and cared for the poor without remuneration, +having a position and salary fixed by law and paid them +semi-annually. These were honorable positions, and the archiatri +were obliged to give instruction in medicine, without pay, to the +poor students. They were allowed to receive fees and donations +from their patients, but not, however, until the danger from the +malady was past. Special laws were enacted to protect them, and +any person subjecting them to an insult was liable to a fine "not +exceeding one thousand pounds." + +An example of Roman practicality is shown in the method of +treating hemorrhage, as described by Aulus Cornelius Celsus (53 +B.C. to 7 A.D.). Hippocrates and Hippocratic writers treated +hemorrhage by application of cold, pressure, styptics, and +sometimes by actual cauterizing; but they knew nothing of the +simple method of stopping a hemorrhage by a ligature tied around +the bleeding vessel. Celsus not only recommended tying the end of +the injured vessel, but describes the method of applying two +ligatures before the artery is divided by the surgeon--a common +practice among surgeons at the present time. The cut is made +between these two, and thus hemorrhage is avoided from either end +of the divided vessel. + +Another Roman surgeon, Heliodorus, not only describes the use of +the ligature in stopping hemorrhage, but also the practice of +torsion--twisting smaller vessels, which causes their lining +membrane to contract in a manner that produces coagulation and +stops hemorrhage. It is remarkable that so simple and practical a +method as the use of the ligature in stopping hemorrhage could +have gone out of use, once it had been discovered; but during the +Middle Ages it was almost entirely lost sight of, and was not +reintroduced until the time of Ambroise Pare, in the sixteenth +century. + +Even at a very early period the Romans recognized the advantage +of surgical methods on the field of battle. Each soldier was +supplied with bandages, and was probably instructed in applying +them, something in the same manner as is done now in all modern +armies. The Romans also made use of military hospitals and had +established a rude but very practical field-ambulance service. +"In every troop or bandon of two or four hundred men, eight or +ten stout fellows were deputed to ride immediately behind the +fighting-line to pick up and rescue the wounded, for which +purpose their saddles had two stirrups on the left side, while +they themselves were provided with water-flasks, and perhaps +applied temporary bandages. They were encouraged by a reward of a +piece of gold for each man they rescued. 'Noscomi' were male +nurses attached to the military hospitals, but not inscribed 'on +strength' of the legions, and were probably for the most part of +the servile class."[6] + +From the time of the early Alexandrians, Herophilus and +Erasistratus, whose work we have already examined, there had been +various anatomists of some importance in the Alexandrian school, +though none quite equal to these earlier workers. The best-known +names are those of Celsus (of whom we have already spoken), who +continued the work of anatomical investigation, and Marinus, who +lived during the reign of Nero, and Rufus of Ephesus. Probably +all of these would have been better remembered by succeeding +generations had their efforts not been eclipsed by those of +Galen. This greatest of ancient anatomists was born at Pergamus +of Greek parents. His father, Nicon, was an architect and a man +of considerable ability. Until his fifteenth year the youthful +Galen was instructed at home, chiefly by his father; but after +that time he was placed under suitable teachers for instruction +in the philosophical systems in vogue at that period. Shortly +after this, however, the superstitious Nicon, following the +interpretations of a dream, decided that his son should take up +the study of medicine, and placed him under the instruction of +several learned physicians. + +Galen was a tireless worker, making long tours into Asia Minor +and Palestine to improve himself in pharmacology, and studying +anatomy for some time at Alexandria. He appears to have been full +of the superstitions of the age, however, and early in his career +made an extended tour into western Asia in search of the +chimerical "jet-stone"--a stone possessing the peculiar qualities +of "burning with a bituminous odor and supposed to possess great +potency in curing such diseases as epilepsy, hysteria, and gout." + +By the time he had reached his twenty-eighth year he had +perfected his education in medicine and returned to his home in +Pergamus. Even at that time he had acquired considerable fame as +a surgeon, and his fellow-citizens showed their confidence in his +ability by choosing him as surgeon to the wounded gladiators +shortly after his return to his native city. In these duties his +knowledge of anatomy aided him greatly, and he is said to have +healed certain kinds of wounds that had previously baffled the +surgeons. + +In the time of Galen dissections of the human body were forbidden +by law, and he was obliged to confine himself to dissections of +the lower animals. He had the advantage, however, of the +anatomical works of Herophilus and Erasistratus, and he must have +depended upon them in perfecting his comparison between the +anatomy of men and the lower animals. It is possible that he did +make human dissections surreptitiously, but of this we have no +proof. + +He was familiar with the complicated structure of the bones of +the cranium. He described the vertebrae clearly, divided them +into groups, and named them after the manner of anatomists of +to-day. He was less accurate in his description of the muscles, +although a large number of these were described by him. Like all +anatomists before the time of Harvey, he had a very erroneous +conception of the circulation, although he understood that the +heart was an organ for the propulsion of blood, and he showed +that the arteries of the living animals did not contain air +alone, as was taught by many anatomists. He knew, also, that the +heart was made up of layers of fibres that ran in certain fixed +directions--that is, longitudinal, transverse, and oblique; but +he did not recognize the heart as a muscular organ. In proof of +this he pointed out that all muscles require rest, and as the +heart did not rest it could not be composed of muscular tissue. + +Many of his physiological experiments were conducted upon +scientific principles. Thus he proved that certain muscles were +under the control of definite sets of nerves by cutting these +nerves in living animals, and observing that the muscles supplied +by them were rendered useless. He pointed out also that nerves +have no power in themselves, but merely conduct impulses to and +from the brain and spinal-cord. He turned this peculiar knowledge +to account in the case of a celebrated sophist, Pausanias, who +had been under the treatment of various physicians for a numbness +in the fourth and fifth fingers of his left hand. These +physicians had been treating this condition by applications of +poultices to the hand itself. Galen, being called in +consultation, pointed out that the injury was probably not in the +hand itself, but in the ulner nerve, which controls sensation in +the fourth and fifth fingers. Surmising that the nerve must have +been injured in some way, he made careful inquiries of the +patient, who recalled that he had been thrown from his chariot +some time before, striking and injuring his back. Acting upon +this information, Galen applied stimulating remedies to the +source of the nerve itself--that is, to the bundle of +nerve-trunks known as the brachial plexus, in the shoulder. To +the surprise and confusion of his fellow-physicians, this method +of treatment proved effective and the patient recovered +completely in a short time. + +Although the functions of the organs in the chest were not well +understood by Galen, he was well acquainted with their anatomy. +He knew that the lungs were covered by thin membrane, and that +the heart was surrounded by a sac of very similar tissue. He made +constant comparisons also between these organs in different +animals, as his dissections were performed upon beasts ranging in +size from a mouse to an elephant. The minuteness of his +observations is shown by the fact that he had noted and described +the ring of bone found in the hearts of certain animals, such as +the horse, although not found in the human heart or in most +animals. + +His description of the abdominal organs was in general accurate. +He had noted that the abdominal cavity was lined with a peculiar +saclike membrane, the peritoneum, which also surrounded most of +the organs contained in the cavity, and he made special note that +this membrane also enveloped the liver in a peculiar manner. The +exactness of the last observation seems the more wonderful when +we reflect that even to-day the medical, student finds a correct +understanding of the position of the folds of the peritoneum one +of the most difficult subjects in anatomy. + +As a practical physician he was held in the highest esteem by the +Romans. The Emperor Marcus Aurelius called him to Rome and +appointed him physician-inordinary to his son Commodus, and on +special occasions Marcus Aurelius himself called in Galen as his +medical adviser. On one occasion, the three army surgeons in +attendance upon the emperor declared that he was about to be +attacked by a fever. Galen relates how "on special command I felt +his pulse, and finding it quite normal, considering his age and +the time of day, I declared it was no fever but a digestive +disorder, due to the food he had eaten, which must be converted +into phlegm before being excreted. Then the emperor repeated +three times, 'That's the very thing,' and asked what was to be +done. I answered that I usually gave a glass of wine with pepper +sprinkled on it, but for you kings we only use the safest +remedies, and it will suffice to apply wool soaked in hot nard +ointment locally. The emperor ordered the wool, wine, etc., to be +brought, and I left the room. His feet were warmed by rubbing +with hot hands, and after drinking the peppered wine, he said to +Pitholaus (his son's tutor), 'We have only one doctor, and that +an honest one,' and went on to describe me as the first of +physicians and the only philosopher, for he had tried many before +who were not only lovers of money, but also contentious, +ambitious, envious, and malignant."[7] + +It will be seen from this that Galen had a full appreciation of +his own abilities as a physician, but inasmuch as succeeding +generations for a thousand years concurred in the alleged +statement made by Marcus Aurelius as to his ability, he is +perhaps excusable for his open avowal of his belief in his +powers. His faith in his accuracy in diagnosis and prognosis was +shown when a colleague once said to him, "I have used the +prognostics of Hippocrates as well as you. Why can I not +prognosticate as well as you?" To this Galen replied, "By God's +help I have never been deceived in my prognosis."[8] It is +probable that this statement was made in the heat of argument, +and it is hardly to be supposed that he meant it literally. + +His systems of treatment were far in advance of his theories +regarding the functions of organs, causes of disease, etc., and +some of them are still first principles with physicians. Like +Hippocrates, he laid great stress on correct diet, exercise, and +reliance upon nature. "Nature is the overseer by whom health is +supplied to the sick," he says. "Nature lends her aid on all +sides, she decides and cures diseases. No one can be saved unless +nature conquers the disease, and no one dies unless nature +succumbs." + +From the picture thus drawn of Galen as an anatomist and +physician, one might infer that he should rank very high as a +scientific exponent of medicine, even in comparison with modern +physicians. There is, however, another side to the picture. His +knowledge of anatomy was certainly very considerable, but many of +his deductions and theories as to the functions of organs, the +cause of diseases, and his methods of treating them, would be +recognized as absurd by a modern school-boy of average +intelligence. His greatness must be judged in comparison with +ancient, not with modern, scientists. He maintained, for example, +that respiration and the pulse-beat were for one and the same +purpose--that of the reception of air into the arteries of the +body. To him the act of breathing was for the purpose of +admitting air into the lungs, whence it found its way into the +heart, and from there was distributed throughout the body by +means of the arteries. The skin also played an important part in +supplying the body with air, the pores absorbing the air and +distributing it through the arteries. But, as we know that he was +aware of the fact that the arteries also contained blood, he must +have believed that these vessels contained a mixture of the two. + +Modern anatomists know that the heart is divided into two +approximately equal parts by an impermeable septum of tough +fibres. Yet, Galen, who dissected the hearts of a vast number of +the lower animals according to his own account, maintained that +this septum was permeable, and that the air, entering one side of +the heart from the lungs, passed through it into the opposite +side and was then transferred to the arteries. + +He was equally at fault, although perhaps more excusably so, in +his explanation of the action of the nerves. He had rightly +pointed out that nerves were merely connections between the brain +and spinal-cord and distant muscles and organs, and had +recognized that there were two kinds of nerves, but his +explanation of the action of these nerves was that "nervous +spirits" were carried to the cavities of the brain by +blood-vessels, and from there transmitted through the body along +the nerve-trunks. + +In the human skull, overlying the nasal cavity, there are two +thin plates of bone perforated with numerous small apertures. +These apertures allow the passage of numerous nerve-filaments +which extend from a group of cells in the brain to the delicate +membranes in the nasal cavity. These perforations in the bone, +therefore, are simply to allow the passage of the nerves. But +Galen gave a very different explanation. He believed that impure +"animal spirits" were carried to the cavities of the brain by the +arteries in the neck and from there were sifted out through these +perforated bones, and so expelled from the body. + +He had observed that the skin played an important part in cooling +the body, but he seems to have believed that the heart was +equally active in overheating it. The skin, therefore, absorbed +air for the purpose of "cooling the heart," and this cooling +process was aided by the brain, whose secretions aided also in +the cooling process. The heart itself was the seat of courage; +the brain the seat of the rational soul; and the liver the seat +of love. + +The greatness of Galen's teachings lay in his knowledge of +anatomy of the organs; his weakness was in his interpretations of +their functions. Unfortunately, succeeding generations of +physicians for something like a thousand years rejected the +former but clung to the latter, so that the advances he had made +were completely overshadowed by the mistakes of his teachings. + + + +XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + +It is a favorite tenet of the modern historian that history is a +continuous stream. The contention has fullest warrant. Sharp +lines of demarcation are an evidence of man's analytical +propensity rather than the work of nature. Nevertheless it would +be absurd to deny that the stream of history presents an +ever-varying current. There are times when it seems to rush +rapidly on; times when it spreads out into a broad--seemingly +static--current; times when its catastrophic changes remind us of +nothing but a gigantic cataract. Rapids and whirlpools, broad +estuaries and tumultuous cataracts are indeed part of the same +stream, but they are parts that vary one from another in their +salient features in such a way as to force the mind to classify +them as things apart and give them individual names. + +So it is with the stream of history; however strongly we insist +on its continuity we are none the less forced to recognize its +periodicity. It may not be desirable to fix on specific dates as +turning-points to the extent that our predecessors were wont to +do. We may not, for example, be disposed to admit that the Roman +Empire came to any such cataclysmic finish as the year 476 A.D., +when cited in connection with the overthrow of the last Roman +Empire of the West, might seem to indicate. But, on the other +hand, no student of the period can fail to realize that a great +change came over the aspect of the historical stream towards the +close of the Roman epoch. + +The span from Thales to Galen has compassed about eight hundred +years--let us say thirty generations. Throughout this period +there is scarcely a generation that has not produced great +scientific thinkers--men who have put their mark upon the +progress of civilization; but we shall see, as we look forward +for a corresponding period, that the ensuing thirty generations +produced scarcely a single scientific thinker of the first rank. +Eight hundred years of intellectual activity --thirty generations +of greatness; then eight hundred years of stasis--thirty +generations of mediocrity; such seems to be the record as viewed +in perspective. Doubtless it seemed far different to the +contemporary observer; it is only in reasonable perspective that +any scene can be viewed fairly. But for us, looking back without +prejudice across the stage of years, it seems indisputable that a +great epoch came to a close at about the time when the barbarian +nations of Europe began to sweep down into Greece and Italy. We +are forced to feel that we have reached the limits of progress of +what historians are pleased to call the ancient world. For about +eight hundred years Greek thought has been dominant, but in the +ensuing period it is to play a quite subordinate part, except in +so far as it influences the thought of an alien race. As we leave +this classical epoch, then, we may well recapitulate in brief its +triumphs. A few words will suffice to summarize a story the +details of which have made up our recent chapters. + +In the field of cosmology, Greek genius has demonstrated that the +earth is spheroidal, that the moon is earthlike in structure and +much smaller than our globe, and that the sun is vastly larger +and many times more distant than the moon. The actual size of the +earth and the angle of its axis with the ecliptic have been +measured with approximate accuracy. It has been shown that the +sun and moon present inequalities of motion which may be +theoretically explained by supposing that the earth is not +situated precisely at the centre of their orbits. A system of +eccentrics and epicycles has been elaborated which serves to +explain the apparent motions of the heavenly bodies in a manner +that may be called scientific even though it is based, as we now +know, upon a false hypothesis. The true hypothesis, which places +the sun at the centre of the planetary system and postulates the +orbital and axial motions of our earth in explanation of the +motions of the heavenly bodies, has been put forward and ardently +championed, but, unfortunately, is not accepted by the dominant +thinkers at the close of our epoch. In this regard, therefore, a +vast revolutionary work remains for the thinkers of a later +period. Moreover, such observations as the precession of the +equinoxes and the moon's evection are as yet unexplained, and +measurements of the earth's size, and of the sun's size and +distance, are so crude and imperfect as to be in one case only an +approximation, and in the other an absurdly inadequate +suggestion. But with all these defects, the total achievement of +the Greek astronomers is stupendous. To have clearly grasped the +idea that the earth is round is in itself an achievement that +marks off the classical from the Oriental period as by a great +gulf. + +In the physical sciences we have seen at least the beginnings of +great things. Dynamics and hydrostatics may now, for the first +time, claim a place among the sciences. Geometry has been +perfected and trigonometry has made a sure beginning. The +conception that there are four elementary substances, earth, +water, air, and fire, may not appear a secure foundation for +chemistry, yet it marks at least an attempt in the right +direction. Similarly, the conception that all matter is made up +of indivisible particles and that these have adjusted themselves +and are perhaps held in place by a whirling motion, while it is +scarcely more than a scientific dream, is, after all, a dream of +marvellous insight. + +In the field of biological science progress has not been so +marked, yet the elaborate garnering of facts regarding anatomy, +physiology, and the zoological sciences is at least a valuable +preparation for the generalizations of a later time. + +If with a map before us we glance at the portion of the globe +which was known to the workers of the period now in question, +bearing in mind at the same time what we have learned as to the +seat of labors of the various great scientific thinkers from +Thales to Galen, we cannot fail to be struck with a rather +startling fact, intimations of which have been given from time to +time--the fact, namely, that most of the great Greek thinkers did +not live in Greece itself. As our eye falls upon Asia Minor and +its outlying islands, we reflect that here were born such men as +Thales, Anaximander, Anaximenes, Heraclitus, Pythagoras, +Anaxagoras, Socrates, Aristarchus, Hipparchus, Eudoxus, +Philolaus, and Galen. From the northern shores of the aegean came +Lucippus, Democritus, and Aristotle. Italy, off to the west, is +the home of Pythagoras and Xenophanes in their later years, and +of Parmenides and Empedocles, Zeno, and Archimedes. Northern +Africa can claim, by birth or by adoption, such names as Euclid, +Apollonius of Perga, Herophilus, Erasistratus, Aristippus, +Eratosthenes, Ctesibius, Hero, Strabo, and Ptolemy. This is but +running over the list of great men whose discoveries have claimed +our attention. Were we to extend the list to include a host of +workers of the second rank, we should but emphasize the same +fact. + +All along we are speaking of Greeks, or, as they call themselves, +Hellenes, and we mean by these words the people whose home was a +small jagged peninsula jutting into the Mediterranean at the +southeastern extremity of Europe. We think of this peninsula as +the home of Greek culture, yet of all the great thinkers we have +just named, not one was born on this peninsula, and perhaps not +one in five ever set foot upon it. In point of fact, one Greek +thinker of the very first rank, and one only, was born in Greece +proper; that one, however, was Plato, perhaps the greatest of +them all. With this one brilliant exception (and even he was born +of parents who came from the provinces), all the great thinkers +of Greece had their origin at the circumference rather than the +centre of the empire. And if we reflect that this circumference +of the Greek world was in the nature of the case the widely +circling region in which the Greek came in contact with other +nations, we shall see at once that there could be no more +striking illustration in all history than that furnished us here +of the value of racial mingling as a stimulus to intellectual +progress. + +But there is one other feature of the matter that must not be +overlooked. Racial mingling gives vitality, but to produce the +best effect the mingling must be that of races all of which are +at a relatively high plane of civilization. In Asia Minor the +Greek mingled with the Semite, who had the heritage of centuries +of culture; and in Italy with the Umbrians, Oscans, and +Etruscans, who, little as we know of their antecedents, have left +us monuments to testify to their high development. The chief +reason why the racial mingling of a later day did not avail at +once to give new life to Roman thought was that the races which +swept down from the north were barbarians. It was no more +possible that they should spring to the heights of classical +culture than it would, for example, be possible in two or three +generations to produce a racer from a stock of draught horses. +Evolution does not proceed by such vaults as this would imply. +Celt, Goth, Hun, and Slav must undergo progressive development +for many generations before the population of northern Europe can +catch step with the classical Greek and prepare to march forward. +That, perhaps, is one reason why we come to a period of stasis or +retrogression when the time of classical activity is over. But, +at best, it is only one reason of several. + +The influence of the barbarian nations will claim further +attention as we proceed. But now, for the moment, we must turn +our eyes in the other direction and give attention to certain +phases of Greek and of Oriental thought which were destined to +play a most important part in the development of the Western +mind--a more important part, indeed, in the early mediaeval +period than that played by those important inductions of science +which have chiefly claimed our attention in recent chapters. The +subject in question is the old familiar one of false inductions +or pseudoscience. In dealing with the early development of +thought and with Oriental science, we had occasion to emphasize +the fact that such false inductions led everywhere to the +prevalence of superstition. In dealing with Greek science, we +have largely ignored this subject, confining attention chiefly to +the progressive phases of thought; but it must not be inferred +from this that Greek science, with all its secure inductions, was +entirely free from superstition. On the contrary, the most casual +acquaintance with Greek literature would suffice to show the +incorrectness of such a supposition. True, the great thinkers of +Greece were probably freer from this thraldom. of false +inductions than any of their predecessors. Even at a very early +day such men as Xenophanes, Empedocles, Anaxagoras, and Plato +attained to a singularly rationalistic conception of the +universe. + +We saw that "the father of medicine," Hippocrates, banished +demonology and conceived disease as due to natural causes. At a +slightly later day the sophists challenged all knowledge, and +Pyrrhonism became a synonym for scepticism in recognition of the +leadership of a master doubter. The entire school of Alexandrians +must have been relatively free from superstition, else they could +not have reasoned with such effective logicality from their +observations of nature. It is almost inconceivable that men like +Euclid and Archimedes, and Aristarchus and Eratosthenes, and +Hipparchus and Hero, could have been the victims of such +illusions regarding occult forces of nature as were constantly +postulated by Oriental science. Herophilus and Erasistratus and +Galen would hardly have pursued their anatomical studies with +equanimity had they believed that ghostly apparitions watched +over living and dead alike, and exercised at will a malign +influence. + +Doubtless the Egyptian of the period considered the work, of the +Ptolemaic anatomists an unspeakable profanation, and, indeed, it +was nothing less than revolutionary--so revolutionary that it +could not be sustained in subsequent generations. We have seen +that the great Galen, at Rome, five centuries after the time of +Herophilus, was prohibited from dissecting the human subject. The +fact speaks volumes for the attitude of the Roman mind towards +science. Vast audiences made up of every stratum of society +thronged the amphitheatre, and watched exultingly while man slew +his fellow-man in single or in multiple combat. Shouts of +frenzied joy burst from a hundred thousand throats when the +death-stroke was given to a new victim. The bodies of the slain, +by scores, even by hundreds, were dragged ruthlessly from the +arena and hurled into a ditch as contemptuously as if pity were +yet unborn and human life the merest bauble. Yet the same eyes +that witnessed these scenes with ecstatic approval would have +been averted in pious horror had an anatomist dared to approach +one of the mutilated bodies with the scalpel of science. It was +sport to see the blade of the gladiator enter the quivering, +living flesh of his fellow-gladiator; it was joy to see the warm +blood spurt forth from the writhing victim while he still lived; +but it were sacrilegious to approach that body with the knife of +the anatomist, once it had ceased to pulsate with life. Life +itself was held utterly in contempt, but about the realm of death +hovered the threatening ghosts of superstition. And such, be it +understood, was the attitude of the Roman populace in the early +and the most brilliant epoch of the empire, before the Western +world came under the influence of that Oriental philosophy which +was presently to encompass it. + +In this regard the Alexandrian world was, as just intimated, far +more advanced than the Roman, yet even there we must suppose that +the leaders of thought were widely at variance with the popular +conceptions. A few illustrations, drawn from Greek literature at +various ages, will suggest the popular attitude. In the first +instance, consider the poems of Homer and of Hesiod. For these +writers, and doubtless for the vast majority of their readers, +not merely of their own but of many subsequent generations, the +world is peopled with a multitude of invisible apparitions, +which, under title of gods, are held to dominate the affairs of +man. It is sometimes difficult to discriminate as to where the +Greek imagination drew the line between fact and allegory; nor +need we attempt to analyse the early poetic narratives to this +end. It will better serve our present purpose to cite three or +four instances which illustrate the tangibility of beliefs based +upon pseudo-scientific inductions. + +Let us cite, for example, the account which Herodotus gives us of +the actions of the Greeks at Plataea, when their army confronted +the remnant of the army of Xerxes, in the year 479 B.C. Here we +see each side hesitating to attack the other, merely because the +oracle had declared that whichever side struck the first blow +would lose the conflict. Even after the Persian soldiers, who +seemingly were a jot less superstitious or a shade more impatient +than their opponents, had begun the attack, we are told that the +Greeks dared not respond at first, though they were falling +before the javelins of the enemy, because, forsooth, the entrails +of a fowl did not present an auspicious appearance. And these +were Greeks of the same generation with Empedocles and Anaxagoras +and aeschylus; of the same epoch with Pericles and Sophocles and +Euripides and Phidias. Such was the scientific status of the +average mind--nay, of the best minds--with here and there a rare +exception, in the golden age of Grecian culture. + +Were we to follow down the pages of Greek history, we should but +repeat the same story over and over. We should, for example, see +Alexander the Great balked at the banks of the Hyphasis, and +forced to turn back because of inauspicious auguries based as +before upon the dissection of a fowl. Alexander himself, to be +sure, would have scorned the augury; had he been the prey of such +petty superstitions he would never have conquered Asia. We know +how he compelled the oracle at Delphi to yield to his wishes; how +he cut the Gordian knot; how he made his dominating personality +felt at the temple of Ammon in Egypt. We know, in a word, that he +yielded to superstitions only in so far as they served his +purpose. Left to his own devices, he would not have consulted an +oracle at the banks of the Hyphasis; or, consulting, would have +forced from the oracle a favorable answer. But his subordinates +were mutinous and he had no choice. Suffice it for our present +purpose that the oracle was consulted, and that its answer turned +the conqueror back. + +One or two instances from Roman history may complete the picture. +Passing over all those mythical narratives which virtually +constitute the early history of Rome, as preserved to us by such +historians as Livy and Dionysius, we find so logical an historian +as Tacitus recording a miraculous achievement of Vespasian +without adverse comment. "During the months when Vespasian was +waiting at Alexandria for the periodical season of the summer +winds, and a safe navigation, many miracles occurred by which the +favor of Heaven and a sort of bias in the powers above towards +Vespasian were manifested." Tacitus then describes in detail the +cure of various maladies by the emperor, and relates that the +emperor on visiting a temple was met there, in the spirit, by a +prominent Egyptian who was proved to be at the same time some +eighty miles distant from Alexandria. + +It must be admitted that Tacitus, in relating that Vespasian +caused the blind to see and the lame to walk, qualifies his +narrative by asserting that "persons who are present attest the +truth of the transaction when there is nothing to be gained by +falsehood." Nor must we overlook the fact that a similar belief +in the power of royalty has persisted almost to our own day. But +no such savor of scepticism attaches to a narrative which Dion +Cassius gives us of an incident in the life of Marcus +Aurelius--an incident that has become famous as the episode of +The Thundering Legion. Xiphilinus has preserved the account of +Dion, adding certain picturesque interpretations of his own. The +original narrative, as cited, asserts that during one of the +northern campaigns of Marcus Aurelius, the emperor and his army +were surrounded by the hostile Quadi, who had every advantage of +position and who presently ceased hostilities in the hope that +heat and thirst would deliver their adversaries into their hands +without the trouble of further fighting. "Now," says Dion, "while +the Romans, unable either to combat or to retreat, and reduced to +the last extremity by wounds, fatigue, heat, and thirst, were +standing helplessly at their posts, clouds suddenly gathered in +great number and rain descended in floods--certainly not without +divine intervention, since the Egyptian Maege Arnulphis, who was +with Marcus Antoninus, is said to have invoked several genii by +the aerial mercury by enchantment, and thus through them had +brought down rain." + +Here, it will be observed, a supernatural explanation is given of +a natural phenomenon. But the narrator does not stop with this. +If we are to accept the account of Xiphilinus, Dion brings +forward some striking proofs of divine interference. Xiphilinus +gives these proofs in the following remarkable paragraph: + +"Dion adds that when the rain began to fall every soldier lifted +his head towards heaven to receive the water in his mouth; but +afterwards others hold out their shields or their helmets to +catch the water for themselves and for their horses. Being set +upon by the barbarians . . . while occupied in drinking, they +would have been seriously incommoded had not heavy hail and +numerous thunderbolts thrown consternation into the ranks of the +enemy. Fire and water were seen to mingle as they left the +heavens. The fire, however, did not reach the Romans, but if it +did by chance touch one of them it was immediately extinguished, +while at the same time the rain, instead of comforting the +barbarians, seemed merely to excite like oil the fire with which +they were being consumed. Some barbarians inflicted wounds upon +themselves as though their blood had power to extinguish flames, +while many rushed over to the side of the Romans, hoping that +there water might save them." + +We cannot better complete these illustrations of pagan credulity +than by adding the comment of Xiphilinus himself. That writer was +a Christian, living some generations later than Dion. He never +thought of questioning the facts, but he felt that Dion's +interpretation of these facts must not go unchallenged. As he +interprets the matter, it was no pagan magician that wrought the +miracle. He even inclines to the belief that Dion himself was +aware that Christian interference, and not that of an Egyptian, +saved the day. "Dion knew," he declares, "that there existed a +legion called The Thundering Legion, which name was given it for +no other reason than for what came to pass in this war," and that +this legion was composed of soldiers from Militene who were all +professed Christians. "During the battle," continues Xiphilinus, +"the chief of the Pretonians , had set at Marcus Antoninus, who +was in great perplexity at the turn events were taking, +representing to him that there was nothing the people called +Christians could not obtain by their prayers, and that among his +forces was a troop composed wholly of followers of that religion. +Rejoiced at this news, Marcus Antoninus demanded of these +soldiers that they should pray to their god, who granted their +petition on the instant, sent lightning among the enemy and +consoled the Romans with rain. Struck by this wonderful success, +the emperor honored the Christians in an edict and named their +legion The Thundering. It is even asserted that a letter existed +by Marcus Antoninus on this subject. The pagans well knew that +the company was called The Thunderers, having attested the fact +themselves, but they revealed nothing of the occasion on which +the leader received the name."[1] + +Peculiar interest attaches to this narrative as illustrating both +credulousness as to matters of fact and pseudo-scientific +explanation of alleged facts. The modern interpreter may suppose +that a violent thunderstorm came up during the course of a battle +between the Romans and the so-called barbarians, and that owing +to the local character of the storm, or a chance discharge of +lightning, the barbarians suffered more than their opponents. We +may well question whether the philosophical emperor himself put +any other interpretation than this upon the incident. But, on the +other hand, we need not doubt that the major part of his soldiers +would very readily accept such an explanation as that given by +Dion Cassius, just as most readers of a few centuries later would +accept the explanation of Xiphilinus. It is well to bear this +thought in mind in considering the static period of science upon +which we are entering. We shall perhaps best understand this +period, and its seeming retrogressions, if we suppose that the +average man of the Middle Ages was no more credulous, no more +superstitious, than the average Roman of an earlier period or +than the average Greek; though the precise complexion of his +credulity had changed under the influence of Oriental ideas, as +we have just seen illustrated by the narrative of Xiphilinus. + + + +APPENDIX + +REFERENCE LIST, NOTES, AND BIBLIOGRAPHIES + + + +CHAPTER I. PREHISTORIC SCIENCE + +Length of the Prehistoric Period.--It is of course quite +impossible to reduce the prehistoric period to any definite +number of years. There are, however, numerous bits of evidence +that enable an anthropologist to make rough estimates as to the +relative lengths of the different periods into which prehistoric +time is divided. Gabriel de Mortillet, one of the most +industrious students of prehistoric archaeology, ventured to give +a tentative estimate as to the numbers of years involved in each +period. He of course claimed for this nothing more than the value +of a scientific guess. It is, however, a guess based on a very +careful study of all data at present available. Mortillet divides +the prehistoric period, as a whole, into four epochs. The first +of these is the preglacial, which he estimates as comprising +seventy-eight thousand years; the second is the glacial, covering +one hundred thousand years; then follows what he terms the +Solutreen, which numbers eleven thousand years; and, finally, the +Magdalenien, comprising thirty-three thousand years. This gives, +for the prehistoric period proper, a term of about two hundred +and twenty-two thousand years. Add to this perhaps twelve +thousand years ushering in the civilization of Egypt, and the six +thousand years of stable, sure chronology of the historical +period, and we have something like two hundred and thirty +thousand or two hundred and forty thousand years as the age of +man. + +"These figures," says Mortillet, "are certainly not exaggerated. +It is even probable that they are below the truth. Constantly new +discoveries are being made that tend to remove farther back the +date of man's appearance." We see, then, according to this +estimate, that about a quarter of a million years have elapsed +since man evolved to a state that could properly be called human. +This guess is as good as another, and it may advantageously be +kept in mind, as it will enable us all along to understand better +than we might otherwise be able to do the tremendous force of +certain prejudices and preconceptions which recent man inherited +from his prehistoric ancestor. Ideas which had passed current as +unquestioned truths for one hundred thousand years or so are not +easily cast aside. + +In going back, in imagination, to the beginning of the +prehistoric period, we must of course reflect, in accordance with +modern ideas on the subject, that there was no year, no +millennium even, when it could be said expressly: "This being was +hitherto a primate, he is now a man." The transition period must +have been enormously long, and the changes from generation to +generation, even from century to century, must have been very +slight. In speaking of the extent of the age of man this must be +borne in mind: it must be recalled that, even if the period were +not vague for other reasons, the vagueness of its beginning must +make it indeterminate. + +Bibliographical Notes.--A great mass of literature has been +produced in recent years dealing with various phases of the +history of prehistoric man. No single work known to the writer +deals comprehensively with the scientific attainments of early +man; indeed, the subject is usually ignored, except where +practical phases of the mechanical arts are in question. But of +course any attempt to consider the condition of primitive man +talies into account, by inference at least, his knowledge and +attainments. Therefore, most works on anthropology, ethnology, +and primitive culture may be expected to throw some light on our +present subject. Works dealing with the social and mental +conditions of existing savages are also of importance, since it +is now an accepted belief that the ancestors of civilized races +evolved along similar lines and passed through corresponding +stages of nascent culture. Herbert Spencer's Descriptive +Sociology presents an unequalled mass of facts regarding existing +primitive races, but, unfortunately, its inartistic method of +arrangement makes it repellent to the general reader. E. B. +Tyler's Primitive Culture and Anthropology; Lord Avebury's +Prehistoric Times, The Origin of Civilization, and The Primitive +Condition of Man; W. Boyd Dawkin's Cave-Hunting and Early Man in +Britain; and Edward Clodd's Childhood of the World and Story of +Primitive Man are deservedly popular. Paul Topinard's Elements +d'Anthropologie Generale is one of the best-known and most +comprehensive French works on the technical phases of +anthropology; but Mortillet's Le Prehistorique has a more popular +interest, owing to its chapters on primitive industries, though +this work also contains much that is rather technical. Among +periodicals, the Revue de l'Ecole d'Anthropologie de Paris, +published by the professors, treats of all phases of +anthropology, and the American Anthropologist, edited by F. W. +Hodge for the American Anthropological Association, and intended +as "a medium of communication between students of all branches of +anthropology," contains much that is of interest from the present +stand-point. The last-named journal devotes a good deal of space +to Indian languages. + + +CHAPTER II. EGYPTIAN SCIENCE + +1 (p. 34). Sir J. Norman Lockyer, The Dawn of Astronomy; a study +of the temple worship and mythology of the ancient Egyptians, +London, 1894. + +2 (p. 43). G. Maspero, Histoire Ancie-nne des Peuples de l'Orient +Classique, Paris, 1895. Translated as (1) The Dawn of +Civilization, (2) The Struggle of the Nations, (3) The Passing of +the Empires, 3 vols., London and New York, 1894-1900. Professor +Maspero is one of the most famous of living Orientalists. His +most important special studies have to do with Egyptology, but +his writings cover the entire field of Oriental antiquity. He is +a notable stylist, and his works are at once readable and +authoritative. + +3 (p. 44). Adolf Erman, Life in Ancient Egypt, London, 1894, p. +352. (Translated from the original German work entitled Aegypten +und aegyptisches Leben in Alterthum, Tilbigen, 1887.) An +altogether admirable work, full of interest for the general +reader, though based on the most erudite studies. + +4 (p. 47). Erman, op. cit., pp. 356, 357. + +5 (p. 48). Erman, op. cit., p. 357. The work on Egyptian medicine +here referred to is Georg Ebers' edition of an Egyptian document +discovered by the explorer whose name it bears. It remains the +most important source of our knowledge of Egyptian medicine. As +mentioned in the text, this document dates from the eighteenth +dynasty--that is to say, from about the fifteenth or sixteenth +century, B.C., a relatively late period of Egyptian history. + +6 (p. 49). Erman, op. cit., p. 357. + +7 (p. 50). The History of Herodotus, pp. 85-90. There are +numerous translations of the famous work of the "father of +history," one of the most recent and authoritative being that of +G. C. Macaulay, M.A., in two volumes, Macmillan & Co., London and +New York, 1890. + +8 (p. 50). The Historical Library of Diodorus the Sicilian, +London, 1700. This most famous of ancient world histories is +difficult to obtain in an English version. The most recently +published translation known to the writer is that of G. Booth, +London, 1814. + +9 (p. 51). Erman, op. cit., p. 357. + +10 (p. 52). The Papyrus Rhind is a sort of mathematical hand-book +of the ancient Egyptians; it was made in the time of the Hyksos +Kings (about 2000 B.C.), but is a copy of an older book. It is +now preserved in the British Museum. + +The most accessible recent sources of information as to the +social conditions of the ancient Egyptians are the works of +Maspero and Erman, above mentioned; and the various publications +of W. M. Flinders Petrie, The Pyramids and Temples of Gizeh, +London, 1883; Tanis I., London, 1885; Tanis H., Nebesheh, and +Defe-nnel, London, 1887; Ten Years' Diggings, London, 1892; Syria +and Egypt from the Tel-el-Amar-na Letters, London, 1898, etc. The +various works of Professor Petrie, recording his explorations +from year to year, give the fullest available insight into +Egyptian archaeology. + +CHAPTER III. SCIENCE OF BABYLONIA AND ASSYRIA + +1 (p. 57). The Medes. Some difference of opinion exists among +historians as to the exact ethnic relations of the conquerors; +the precise date of the fall of Nineveh is also in doubt. + +2 (p. 57). Darius. The familiar Hebrew narrative ascribes the +first Persian conquest of Babylon to Darius, but inscriptions of +Cyrus and of Nabonidus, the Babylonian king, make it certain that +Cyrus was the real conqueror. These inscriptions are preserved on +cylinders of baked clay, of the type made familiar by the +excavation of the past fifty years, and they are invaluable +historical documents. + +3 (p. 58). Berosus. The fragments of Berosus have been translated +by L. P. Cory, and included in his Ancient Fragments of +Phenician, Chaldean, Egyptian, and Other Writers, London, 1826, +second edition, 1832. + +4 (p. 58). Chaldean learning. Recent writers reserve the name +Chaldean for the later period of Babylonian history-- the time +when the Greeks came in contact with the Mesopotamians--in +contradistinction to the earlier periods which are revealed to us +by the archaeological records. + +5 (p. 59) King Sargon of Agade. The date given for this early +king must not be accepted as absolute; but it is probably +approximately correct. + +6 (p. 59). Nippur. See the account of the early expeditions as +recorded by the director, Dr. John P. Peters, Nippur, or +explorations and adventures, etc., New York and London, 1897. + +7 (p. 62). Fritz Hommel, Geschichte Babyloniens und Assyriens, +Berlin, 1885. + +8 (p. 63). R. Campbell Thompson, Reports of the Magicians and +Astrologers of Nineveh and Babylon, London, 1900, p. xix. + +9 (p. 64). George Smith, The Assyrian Canon, p. 21. + +10 (p. 64). Thompson, op. cit., p. xix. + +11 (p. 65). Thompson, op. cit., p. 2. + +12 (p. 67). Thompson, op. cit., p. xvi. + +13 (p. 68). Sextus Empiricus, author of Adversus Mathematicos, +lived about 200 A.D. + +14 (p. 68). R. Campbell Thompson, op. cit., p. xxiv. + +15 (p. 72). Records of the Past (editor, Samuel Birch), Vol. +III., p. 139. + +16 (p. 72). Ibid., Vol. V., p. 16. + +17 (p. 72). Quoted in Records of the Past, Vol. III., p. 143, +from the Translations of the Society of Biblical Archeology, vol. +II., p. 58. + +18 (p. 73). Records of the Past, vol. L, p. 131. + +19 (p. 73). Ibid., vol. V., p. 171. + +20 (p. 74). Ibid., vol. V., p. 169. + +21 (p. 74). Joachim Menant, La Bibliotheque du Palais de Ninive, +Paris, 188o. + +22 (p. 76). Code of Khamurabi. This famous inscription is on a +block of black diorite nearly eight feet in height. It was +discovered at Susa by the French expedition under M. de Morgan, +in December, 1902. We quote the translation given in The +Historians' History of the World, edited by Henry Smith Williams, +London and New York, 1904, Vol. I, p. 510. + +23 (p. 77). The Historical Library of Diodorus Siculus, p. 519. + +24 (p. 82). George S. Goodspeed, Ph.D., History of the +Babylonians and Assyrians, New York, 1902. + +25 (p. 82). George Rawlinson, Great Oriental Monarchies, (second +edition, London, 1871), Vol. III., pp. 75 ff. + +Of the books mentioned above, that of Hommel is particularly full +in reference to culture development; Goodspeed's small volume +gives an excellent condensed account; the original documents as +translated in the various volumes of Records of the Past are full +of interest; and Menant's little book is altogether admirable. +The work of excavation is still going on in old Babylonia, and +newly discovered texts add from time to time to our knowledge, +but A. H. Layard's Nineveh and its Remains (London, 1849) still +has importance as a record of the most important early +discoveries. The general histories of Antiquity of Duncker, +Lenormant, Maspero, and Meyer give full treatment of Babylonian +and Assyrian development. Special histories of Babylonia and +Assyria, in addition to these named above, are Tiele's +Babylonisch-Assyrische Geschichte (Zwei Tiele, Gotha, 1886-1888); +Winckler's Geschichte Babyloniens und Assyriens (Berlin, +1885-1888), and Rogers' History of Babylonia and Assyria, New +York and London, 1900, the last of which, however, deals almost +exclusively with political history. Certain phases of science, +particularly with reference to chronology and cosmology, are +treated by Edward Meyer (Geschichte des Alterthum, Vol. I., +Stuttgart, 1884), and by P. Jensen (Die Kosmologie der +Babylonier, Strassburg, 1890), but no comprehensive specific +treatment of the subject in its entirety has yet been attempted. + +CHAPTER IV. THE DEVELOPMENT OF THE ALPHABET + +1 (p. 87). Vicomte E. de Rouge, Memoire sur l'Origine Egyptienne +de l'Alphabet Phinicien, Paris, 1874. + +2 (p. 88). See the various publications of Mr. Arthur Evans. + +3 (p. 80). Aztec and Maya writing. These pictographs are still in +the main undecipherable, and opinions differ as to the exact +stage of development which they represent. + +4 (p. 90). E. A. Wallace Budge's First Steps in Egyptian, London, +1895, is an excellent elementary work on the Egyptian writing. +Professor Erman's Egyptian Grammar, London, 1894, is the work of +perhaps the foremost living Egyptologist. + +5 (P. 93). Extant examples of Babylonian and Assyrian writing +give opportunity to compare earlier and later systems, so the +fact of evolution from the pictorial to the phonetic system rests +on something more than mere theory. + +6 (p. 96). Friedrich Delitzsch, Assyrischc Lesestucke mit +grammatischen Tabellen und vollstdndigem Glossar einfiihrung in +die assyrische und babylonische Keilschrift-litteratur bis hinauf +zu Hammurabi, Leipzig, 1900. + +7 (p. 97). It does not appear that the Babylonians thcmselves +ever gave up the old system of writing, so long as they retained +political autonomy. + +8 (p. 101). See Isaac Taylor's History of the Alphabet; an +Account of the origin and Development of Letters, new edition, 2 +vols., London, 1899. + +For facsimiles of the various scripts, see Henry Smith Williams' +History of the Art Of Writing, 4 vols, New York and London, +1902-1903. + +CHAPTER V. THE BEGINNINGS OF GREEK SCIENCE + +1 (p. III). Anaximander, as recorded by Plutarch, vol. VIII-. See +Arthur Fairbanks'First Philosophers of Greece: an Edition and +Translation of the Remaining Fragments of the Pre-Socratic +Philosophers, together with a Translation of the more Important +Accounts of their Opinions Contained in the Early Epitomcs of +their Works, London, 1898. This highly scholarly and extremely +useful book contains the Greek text as well as translations. + +CHAPTER VI. THE EARLY GREEK PHILOSOPHERS IN ITALY + +1 (p. 117). George Henry Lewes, A Biographical History of +Philosophy from its Origin in Greece down to the Present Day, +enlarged edition, New York, 1888, p. 17. + +2 (p. 121). Diogenes Laertius, The Lives and Opinions of Eminent +Philosophers, C. D. Yonge's translation, London, 1853, VIII., p. +153. + +3 (p. 121). Alexander, Successions of Philosophers. + +4 (p. 122). "All over its centre." Presumably this is intended to +refer to the entire equatorial region. + +5 (p. 125). Laertius, op. cit., pp. 348-351. + +6 (p. 128). Arthur Fairbanks, The First Philosophers of Greece +London, 1898, pp. 67-717. + +7 (p. 129). Ibid., p. 838. + +8 (p. 130). Ibid., p. 109. + +9 (p. 130). Heinrich Ritter, The History of Ancient Philosophy, +translated from the German by A. J. W. Morrison, 4 vols., London, +1838, vol, I., p. 463. + +10 (p. 131). Ibid., p. 465. + +11 (p. 132). George Henry Lewes, op. cit., p. 81. + +12 (p. 135). Fairbanks, op. cit., p. 201. + +13 (p. 136). Ibid., P. 234. + +14 (p. 137). Ibid., p. 189. + +15 (p. 137). Ibid., P. 220. + +16 (p. 138). Ibid., p. 189. + +17 (p. 138). Ibid., p. 191. + +CHAPTER VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD + +1 (p. 150). Theodor Gomperz, Greek Thinkers: a History of Ancient +Philosophy (translated from the German by Laurie Magnes), New +York, 190 1, pp. 220, 221. + +2 (p. 153). Aristotle's Treatise on Respiration, ch. ii. + +3 (p. 159). Fairbanks' translation of the fragments of +Anaxagoras, in The First Philosophers of Greece, pp. 239-243. + +CHAPTER VIII. POST-SOCRATIC SCIENCE AT ATHENS + +1 (p. 180). Alfred William Bern, The Philosophy of Greece +Considered in Relation to the Character and History of its +People, London, 1898, p. 186. + +2 (p. 183). Aristotle, quoted in William Whewell's History of the +Inductive Sciences (second edition, London, 1847), Vol. II., p. +161. + +CHAPTER IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC +PERIOD + +1 (p. 195). Tertullian's Apologeticus. + +2 (p. 205). We quote the quaint old translation of North, printed +in 1657. + +CHAPTER X. SCIENCE OF THE ROMAN PERIOD + +1 (p. 258). The Geography of Strabo, translated by H. C. Hamilton +and W. Falconer, 3 vols., London, 1857, Vol. I, pp. 19, 20. + +2 (p. 260). Ibid., p. 154. + +3 (p. 263). Ibid., pp. 169, 170. + +4 (p. 264) Ibid., pp. 166, 167. + +5 (p. 271). K. 0. Miller and John W. Donaldson, The History of +the Literature of Greece, 3 vols., London, Vol. III., p. 268. + + +6 (p. 276). E. T. Withington, Medical History fron., the Earliest +Times, London, 1894, p. 118. + +7 (p. 281). Ibid. + +8 (p. 281). Johann Hermann Bass, History of Medicine, New York, +1889. + +CHAPTER XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE + +(p. 298). Dion Cassius, as preserved by Xiphilinus. Our extract +is quoted from the translation given in The Historians' History +of the World (edited by Henry Smith Williams), 25 vols., London +and New York, 1904, Vol. VI., p. 297 ff. + + +[For further bibliographical notes, the reader is referred to the +Appendix of volume V.] + + + + + +End of Project Gutenberg Etext of A History of Science, V 1, by Williams + diff --git a/old/1hsci10.zip b/old/1hsci10.zip Binary files differnew file mode 100644 index 0000000..315a1d8 --- /dev/null +++ b/old/1hsci10.zip |