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diff --git a/42968-8.txt b/42968-8.txt deleted file mode 100644 index 3995c4d..0000000 --- a/42968-8.txt +++ /dev/null @@ -1,12514 +0,0 @@ -The Project Gutenberg EBook of The Riddle of the Universe at the close of -the nineteenth century, by Ernst Haeckel - -This eBook is for the use of anyone anywhere at no cost and with -almost no restrictions whatsoever. You may copy it, give it away or -re-use it under the terms of the Project Gutenberg License included -with this eBook or online at www.gutenberg.org/license - - -Title: The Riddle of the Universe at the close of the nineteenth century - -Author: Ernst Haeckel - -Translator: Joseph McCabe - -Release Date: June 17, 2013 [EBook #42968] - -Language: English - -Character set encoding: ISO-8859-1 - -*** START OF THIS PROJECT GUTENBERG EBOOK THE RIDDLE OF THE UNIVERSE *** - - - - -Produced by Charlene Taylor, Paul Clark, Marilynda -Fraser-Cunliffe and the Online Distributed Proofreading -Team at http://www.pgdp.net - - - - - - - Transcriber's Note: - - Every effort has been made to replicate this text as faithfully as - possible, including inconsistencies in hyphenation. It seems that - the italic typeface used in this book did not have an ae ligature. - Names of genera and higher taxonomic groups are not capitalized in - the printed book: they have bee left unchanged. Some changes have - been made. They are listed at the end of the text. - - Italic text has been marked with _underscores_. - OE ligatures have been expanded. - - - - -THE RIDDLE OF THE UNIVERSE - - -[Illustration: ERNST HAECKEL] - - - - - THE RIDDLE - OF THE UNIVERSE - - _AT THE CLOSE OF - THE NINETEENTH CENTURY_ - - BY - - ERNST HAECKEL - - (Ph.D., M.D., LL.D., Sc.D., and Professor at the - University of Jena) - - AUTHOR OF "THE HISTORY OF CREATION" - "THE EVOLUTION OF MAN" ETC. - - TRANSLATED BY - - JOSEPH McCABE - - [Illustration] - - HARPER & BROTHERS PUBLISHERS - NEW YORK AND LONDON - 1905 - - - - - Copyright, 1900, by HARPER & BROTHERS. - - _All rights reserved._ - - - - -CONTENTS - - - PAGE - - AUTHOR'S PREFACE v - - TRANSLATOR'S PREFACE xi - - CHAPTER I - THE NATURE OF THE PROBLEM 1 - - CHAPTER II - OUR BODILY FRAME 22 - - CHAPTER III - OUR LIFE 39 - - CHAPTER IV - OUR EMBRYONIC DEVELOPMENT 53 - - CHAPTER V - THE HISTORY OF OUR SPECIES 71 - - CHAPTER VI - THE NATURE OF THE SOUL 88 - - CHAPTER VII - PSYCHIC GRADATIONS 108 - - CHAPTER VIII - THE EMBRYOLOGY OF THE SOUL 132 - - CHAPTER IX - THE PHYLOGENY OF THE SOUL 148 - - CHAPTER X - CONSCIOUSNESS 170 - - CHAPTER XI - THE IMMORTALITY OF THE SOUL 188 - - CHAPTER XII - THE LAW OF SUBSTANCE 211 - - CHAPTER XIII - THE EVOLUTION OF THE WORLD 233 - - CHAPTER XIV - THE UNITY OF NATURE 254 - - CHAPTER XV - GOD AND THE WORLD 275 - - CHAPTER XVI - KNOWLEDGE AND BELIEF 292 - - CHAPTER XVII - SCIENCE AND CHRISTIANITY 308 - - CHAPTER XVIII - OUR MONISTIC RELIGION 331 - - CHAPTER XIX - OUR MONISTIC ETHICS 347 - - CHAPTER XX - SOLUTION OF THE WORLD-PROBLEMS 365 - - CONCLUSION 380 - - INDEX 385 - - - - -AUTHOR'S PREFACE - - -The present study of the monistic philosophy is intended for thoughtful -readers of every condition who are united in an honest search for the -truth. An intensification of this effort of man to attain a knowledge -of the truth is one of the most salient features of the nineteenth -century. That is easily explained, in the first place, by the immense -progress of science, especially in its most important branch, the -history of humanity; it is due, in the second place, to the open -contradiction that has developed during the century between science -and the traditional "Revelation"; and, finally, it arises from the -inevitable extension and deepening of the rational demand for an -elucidation of the innumerable facts that have been recently brought to -light, and for a fuller knowledge of their causes. - -Unfortunately, this vast progress of empirical knowledge in our -"Century of Science" has not been accompanied by a corresponding -advancement of its theoretical interpretation--that higher knowledge of -the causal nexus of individual phenomena which we call philosophy. We -find, on the contrary, that the abstract and almost wholly metaphysical -science which has been taught in our universities for the last hundred -years under the name of "philosophy" is far from assimilating our -hard-earned treasures of experimental research. On the other hand, we -have to admit, with equal regret, that most of the representatives -of what is called "exact science" are content with the special care -of their own narrow branches of observation and experiment, and -deem superfluous the deeper study of the universal connection of -the phenomena they observe--that is, philosophy. While these pure -empiricists "do not see the wood for the trees," the metaphysicians, on -the other hand, are satisfied with the mere picture of the wood, and -trouble not about its individual trees. The idea of a "philosophy of -nature," to which both those methods of research, the empirical and the -speculative, naturally converge, is even yet contemptuously rejected by -large numbers of representatives of both tendencies. - -This unnatural and fatal opposition between science and philosophy, -between the results of experience and of thought, is undoubtedly -becoming more and more onerous and painful to thoughtful people. That -is easily proved by the increasing spread of the immense popular -literature of "natural philosophy" which has sprung up in the course -of the last half-century. It is seen, too, in the welcome fact that, -in spite of the mutual aversion of the scientific observer and the -speculative philosopher, nevertheless eminent thinkers from both -camps league themselves in a united effort to attain the solution -of that highest object of inquiry which we briefly denominate the -"world-riddles." The studies of these "world-riddles" which I offer in -the present work cannot reasonably claim to give a perfect solution of -them; they merely offer to a wide circle of readers a critical inquiry -into the problem, and seek to answer the question as to how nearly we -have approached that solution at the present day. What stage in the -attainment of truth have we actually arrived at in this closing year of -the nineteenth century? What progress have we really made during its -course towards that immeasurably distant goal? - -The answer which I give to these great questions must, naturally, be -merely subjective and only partly correct; for my knowledge of nature -and my ability to interpret its objective reality are limited, as are -those of every man. The one point that I can claim for it, and which, -indeed, I must ask of my strongest opponents, is that my Monistic -Philosophy is sincere from beginning to end--it is the complete -expression of the conviction that has come to me, after many years of -ardent research into Nature and unceasing reflection, as to the true -basis of its phenomena. For fully half a century has my mind's work -proceeded, and I now, in my sixty-sixth year, may venture to claim -that it is mature; I am fully convinced that this "ripe fruit" of the -tree of knowledge will receive no important addition and suffer no -substantial modification during the brief spell of life that remains to -me. - -I presented all the essential and distinctive elements of my monistic -and genetic philosophy thirty-three years ago, in my _General -Morphology of Organisms_, a large and laborious work, which has had but -a limited circulation. It was the first attempt to apply in detail the -newly established theory of evolution to the whole science of organic -forms. In order to secure the acceptance of at least one part of the -new thought which it contained, and to kindle a wider interest in the -greatest advancement of knowledge that our century has witnessed, I -published my _Natural History of Creation_ two years afterwards. -As this less complicated work, in spite of its great defects, ran -into nine large editions and twelve different translations, it has -contributed not a little to the spread of monistic views. The same -may be said of the less known _Anthropogeny_[1] (1874), in which I -set myself the difficult task of rendering the most important facts -of the theory of man's descent accessible and intelligible to the -general reader; the fourth, enlarged, edition of that work appeared in -1891. In the paper which I read at the fourth International Congress -of Zoology at Cambridge, in 1898, on "Our Present Knowledge of the -Descent of Man"[2] (a seventh edition of which appeared in 1899), I -treated certain significant and particularly valuable advances which -this important branch of anthropology has recently made. Other isolated -questions of our modern natural philosophy, which are peculiarly -interesting, have been dealt with in my _Collected Popular Lectures on -the Subject of Evolution_ (1878). Finally, I have briefly presented -the broad principles of my monistic philosophy and its relation to the -dominant faith in my _Confession of Faith of a Man of Science: Monism -as a Connecting Link between Religion and Science_[3] (1892, eighth -edition, 1899). - -The present work on _The Riddle of the Universe_ is the continuation, -confirmation, and integration of the views which I have urged for a -generation in the aforesaid volumes. It marks the close of my studies -on the monistic conception of the universe. The earlier plan, which -I projected many years ago, of constructing a complete "System of -Monistic Philosophy" on the basis of evolution will never be carried -into effect now. My strength is no longer equal to the task, and many -warnings of approaching age urge me to desist. Indeed, I am wholly a -child of the nineteenth century, and with its close I draw the line -under my life's work. - -The vast extension of human knowledge which has taken place during -the present century, owing to a happy division of labor, makes -it impossible to-day to range over all its branches with equal -thoroughness, and to show their essential unity and connection. -Even a genius of the highest type, having an equal command of every -branch of science, and largely endowed with the artistic faculty of -comprehensive presentation, would be incapable of setting forth a -complete view of the cosmos in the space of a moderate volume. My own -command of the various branches of science is uneven and defective, -so that I can attempt no more than to sketch the general plan of such -a world-picture, and point out the pervading unity of its parts, -however imperfect be the execution. Thus it is that this work on the -world-enigma has something of the character of a sketch-book, in which -studies of unequal value are associated. As the material of the book -was partly written many years ago, and partly produced for the first -time during the last few years, the composition is, unfortunately, -uneven at times; repetitions, too, have proved unavoidable. I trust -those defects will be overlooked. - -In taking leave of my readers, I venture the hope that, through my -sincere and conscientious work--in spite of its faults, of which I am -not unconscious--I have contributed a little towards the solution -of the great enigma. Amid the clash of theories, I trust that I have -indicated to many a reader who is absorbed in the zealous pursuit of -purely rational knowledge that path which, it is my firm conviction, -alone leads to the truth--the path of empirical investigation and of -the Monistic Philosophy which is based upon it. - - ERNST HAECKEL. - -JENA, GERMANY. - - - - -PREFACE - - -The hour is close upon us when we shall commence our retrospect of one -of the most wonderful sections of time that was ever measured by the -sweep of the earth. Already the expert is at work, dissecting out and -studying his particular phase of that vast world of thought and action -we call the nineteenth century. Art, literature, commerce, industry, -politics, ethics--all have their high interpreters among us; but in -the chance of life it has fallen out that there is none to read aright -for us, in historic retrospect, what after ages will probably regard -as the most salient feature of the nineteenth century--the conflict -of theology with philosophy and science. The pens of our Huxleys, -and Tyndalls, and Darwins lie where they fell; there is none left in -strength among us to sum up the issues of that struggle with knowledge -and sympathy. - -In these circumstances it has been thought fitting that we should -introduce to English readers the latest work of Professor Haeckel. -Germany, as the reader will quickly perceive, is witnessing the same -strange reaction of thought that we see about us here in England, -yet _Die Welträthsel_ found an immediate and very extensive circle -of readers. One of the most prominent zoologists of the century, -Professor Haeckel, has a unique claim to pronounce with authority, from -the scientific side, on what is known as "the conflict of science and -religion." In the contradictory estimates that are urged on us--for -the modern ecclesiastic is as emphatic in his assurance that the -conflict has ended favorably to theology as the rationalist is with his -counter-assertion--the last words of one of the leading combatants of -the second half of the century, still, happily, in full vigor of mind, -will be heard with respect and close attention. - -A glance at the index of the work suffices to indicate its comprehensive -character. The judgment of the distinguished scientist cannot fail -to have weight on all the topics included; yet the reader will soon -discover a vein of exceptionally interesting thought in the chapters -on evolution. The evolution of the human body is no longer a matter -of serious dispute. It has passed the first two tribunals--those of -theology and of an _à priori_ philosophy--and is only challenged at the -third and last--that of empirical proof--by the decorative heads of -scientific bodies and a few isolated thinkers. - - "_Apparent rari nantes in gurgite vasto._" - -But the question of the evolution of the human mind, or soul, has been -successfully divorced from that of the body. Roman Catholic advanced -theologians, whose precise terminology demanded a clear position, admit -the latter and deny the former categorically. Other theologians, and -many philosophers, have still a vague notion that the evidence for -the one does not impair their sentimental objection to the other. Dr. -Haeckel's work summarizes the evidence for the evolution of mind in -a masterly and profoundly interesting fashion. It seems impossible to -follow his broad survey of the psychic world, from protist to man, -without bearing away a conviction of the natural origin of every power -and content of the human soul. - - TRANSLATOR. - -_October, 1900._ - - - - -THE RIDDLE OF THE UNIVERSE - - - - -CHAPTER I - -THE NATURE OF THE PROBLEM - - The Condition of Civilization and of Thought at the Close of - the Nineteenth Century--Progress of Our Knowledge of Nature, - of the Organic and Inorganic Sciences--The Law of Substance - and the Law of Evolution--Progress of Technical Science and - of Applied Chemistry--Stagnancy in other Departments of - Life: Legal and Political Administration, Education, and the - Church--Conflict of Reason and Dogma--Anthropism--Cosmological - Perspective--Cosmological Theorems--Refutation of the Delusion - of Man's Importance--Number of "World-Riddles"--Criticism of - the "Seven" Enigmas--The Way to Solve Them--Function of the - Senses and of the Brain--Induction and Deduction--Reason, - Sentiment, and Revelation--Philosophy and Science--Experience and - Speculation--Dualism and Monism - - -The close of the nineteenth century offers one of the most remarkable -spectacles to the thoughtful observer. All educated people are -agreed that it has in many respects immeasurably outstripped its -predecessors, and has achieved tasks that were deemed impracticable at -its commencement. An entirely new character has been given to the whole -of our modern civilization, not only by our astounding theoretical -progress in sound knowledge of nature, but also by the remarkably -fertile practical application of that knowledge in technical science, -industry, commerce, and so forth. On the other hand, however, we have -made little or no progress in moral and social life, in comparison with -earlier centuries; at times there has been serious reaction. And from -this obvious conflict there have arisen, not only an uneasy sense of -dismemberment and falseness, but even the danger of grave catastrophes -in the political and social world. It is, then, not merely the right, -but the sacred duty, of every honorable and humanitarian thinker to -devote himself conscientiously to the settlement of that conflict, -and to warding off the dangers that it brings in its train. In our -conviction this can only be done by a courageous effort to attain the -truth, and by the formation of a clear view of the world--a view that -shall be based on truth and conformity to reality. - -If we recall to mind the imperfect condition of science at the -beginning of the century, and compare this with the magnificent -structure of its closing years, we are compelled to admit that -marvellous progress has been made during its course. Every single -branch of science can boast that it has, especially during the latter -half of the century, made numerous acquisitions of the utmost value. -Both in our microscopic knowledge of the little and in our telescopic -investigation of the great we have attained an invaluable insight -that seemed inconceivable a hundred years ago. Improved methods of -microscopic and biological research have not only revealed to us an -invisible world of living things in the kingdom of the protists, full -of an infinite wealth of forms, but they have taught us to recognize in -the tiny cell the all-pervading "elementary organism" of whose social -communities--the tissues--the body of every multicellular plant and -animal, even that of man, is composed. This anatomical knowledge is -of extreme importance; and it is supplemented by the embryological -discovery that each of the higher multicellular organisms is developed -out of one simple cell, the impregnated ovum. The "cellular theory," -which has been founded on that discovery, has given us the first true -interpretation of the physical, chemical, and even the psychological -processes of life--those mysterious phenomena for whose explanation -it had been customary to postulate a supernatural "vital force" or -"immortal soul." Moreover, the true character of disease has been made -clear and intelligible to the physician for the first time by the -cognate science of Cellular Pathology. - -The discoveries of the nineteenth century in the inorganic world are no -less important. Physics has made astounding progress in every section -of its province--in optics and acoustics, in magnetism and electricity, -in mechanics and thermo-dynamics; and, what is still more important, -it has proved the unity of the forces of the entire universe. The -mechanical theory of heat has shown how intimately they are connected, -and how each can, in certain conditions, transform itself directly -into another. Spectral analysis has taught us that the same matter -which enters into the composition of all bodies on earth, including -its living inhabitants, builds up the rest of the planets, the sun, -and the most distant stars. Astro-physics has considerably enlarged -our cosmic perspective in revealing to us, in the immeasurable depths -of space, millions of circling spheres larger than our earth, and, -like it, in endless transformation, in an eternal rhythm of life and -death. Chemistry has introduced us to a multitude of new substances, -all of which arise from the combination of a few (about seventy) -elements that are incapable of further analysis; some of them play a -most important part in every branch of life. It has been shown that one -of these elements--carbon--is the remarkable substance that effects -the endless variety of organic syntheses, and thus may be considered -"the chemical basis of life." All the particular advances, however, of -physics and chemistry yield in theoretical importance to the discovery -of the great law which brings them all to one common focus, the "Law -of Substance." As this fundamental cosmic law establishes the eternal -persistence of matter and force, their unvarying constancy throughout -the entire universe, it has become the pole-star that guides our -Monistic Philosophy through the mighty labyrinth to a solution of the -world-problem. - -Since we intend to make a general survey of the actual condition of -our knowledge of nature and its progress during the present century in -the following chapters, we shall delay no longer with the review of -its particular branches. We would only mention one important advance, -which was contemporary with the discovery of the law of substance, and -which supplements it--the establishment of the theory of evolution. -It is true that there were philosophers who spoke of the evolution -of things a thousand years ago; but the recognition that such a law -dominates the entire universe, and that the world is nothing else than -an eternal "evolution of substance," is a fruit of the nineteenth -century. It was not until the second half of this century that it -attained to perfect clearness and a universal application. The immortal -merit of establishing the doctrine on an empirical basis, and pointing -out its world-wide application, belongs to the great scientist Charles -Darwin; he it was who, in 1859, supplied a solid foundation for the -theory of descent, which the able French naturalist Jean Lamarck had -already sketched in its broad outlines in 1809, and the fundamental -idea of which had been almost prophetically enunciated in 1799 by -Germany's greatest poet and thinker, Wolfgang Goethe. In that theory we -have the key to "the question of all questions," to the great enigma -of "the place of man in nature," and of his natural development. If we -are in a position to-day to recognize the sovereignty of the law of -evolution--and, indeed, of a monistic evolution--in every province of -nature, and to use it, in conjunction with the law of substance, for a -simple interpretation of all natural phenomena, we owe it chiefly to -those three distinguished naturalists; they shine as three stars of the -first magnitude amid all the great men of the century. - -This marvellous progress in a theoretical knowledge of nature has -been followed by a manifold practical application in every branch -of civilized life. If we are to-day in the "age of commerce," if -international trade and communication have attained dimensions beyond -the conception of any previous age, if we have transcended the limits -of space and time by our telegraph and telephone, we owe it, in the -first place, to the technical advancement of physics, especially in -the application of steam and electricity. If, in photography, we can, -with the utmost ease, compel the sunbeam to create for us in a moment's -time a correct picture of any object we like; if we have made enormous -progress in agriculture, and in a variety of other pursuits; if, in -surgery, we have brought an infinite relief to human pain by our -chloroform and morphia, our antiseptics and serous therapeutics, we -owe it all to applied chemistry. But it is so well known how much we -have surpassed all earlier centuries through these and other scientific -discoveries that we need linger over the question no longer. - -While we look back with a just pride on the immense progress of the -nineteenth century in a knowledge of nature and in its practical -application, we find, unfortunately, a very different and far from -agreeable picture when we turn to another and not less important -province of modern life. To our great regret we must endorse the words -of Alfred Wallace: "Compared with our astounding progress in physical -science and its practical application, our system of government, of -administrative justice, and of national education, and our entire -social and moral organization, remain in a state of barbarism." To -convince ourselves of the truth of this grave indictment we need only -cast an unprejudiced glance at our public life, or look into the mirror -that is daily offered to us by the press, the organ of public sentiment. - -We begin our review with justice, the _fundamentum regnorum_. No one -can maintain that its condition to-day is in harmony with our advanced -knowledge of man and the world. Not a week passes in which we do not -read of judicial decisions over which every thoughtful man shakes his -head in despair; many of the decisions of our higher and lower courts -are simply unintelligible. We are not referring in the treatment of -this particular "world-problem" to the fact that many modern states, in -spite of their paper constitutions, are really governed with absolute -despotism, and that many who occupy the bench give judgment less in -accordance with their sincere conviction than with wishes expressed -in higher quarters. We readily admit that the majority of judges and -counsel decide conscientiously, and err simply from human frailty. -Most of their errors, indeed, are due to defective preparation. It is -popularly supposed that these are just the men of highest education, -and that on that very account they have the preference in nominations -to different offices. However, this famed "legal education" is for the -most part rather of a formal and technical character. They have but a -superficial acquaintance with that chief and peculiar object of their -activity, the human organism, and its most important function, the -mind. That is evident from the curious views as to the liberty of the -will, responsibility, etc., which we encounter daily. I once told an -eminent jurist that the tiny spherical ovum from which every man is -developed is as truly endowed with life as the embryo of two, or seven, -or even nine months; he laughed incredulously. Most of the students -of jurisprudence have no acquaintance with anthropology, psychology, -and the doctrine of evolution--the very first requisites for a correct -estimate of human nature. They have "no time" for it; their time is -already too largely bespoken for an exhaustive study of beer and wine -and for the noble art of fencing. The rest of their valuable study-time -is required for the purpose of learning some hundreds of paragraphs of -law books, a knowledge of which is supposed to qualify the jurist for -any position whatever in our modern civilized community. - -We shall touch but lightly on the unfortunate province of politics, for -the unsatisfactory condition of the modern political world is only too -familiar. In a great measure its evils are due to the fact that most of -our officials are jurists--that is, men of high technical education, -but utterly devoid of that thorough knowledge of human nature which is -only obtained by the study of comparative anthropology and the monistic -psychology--men without an acquaintance with those social relations of -which we find the earlier types in comparative zoology and the theory -of evolution, in the cellular theory, and the study of the protists. We -can only arrive at a correct knowledge of the structure and life of the -social body, the state, through a scientific knowledge of the structure -and life of the individuals who compose it, and the cells of which they -are in turn composed. If our political rulers and our "representatives -of the people" possessed this invaluable biological and anthropological -knowledge, we should not find our journals so full of the sociological -blunders and political nonsense which at present are far from adorning -our parliamentary reports, and even many of our official documents. -Worst of all is it when the modern state flings itself into the arms -of the reactionary Church, and when the narrow-minded self-interest -of parties and the infatuation of short-sighted party-leaders lend -their support to the hierarchy. Then are witnessed such sad scenes -as the German Reichstag puts before our eyes even at the close of -the nineteenth century. We have the spectacle of the educated German -people in the power of the ultramontane Centre, under the rule of the -Roman papacy, which is its bitterest and most dangerous enemy. Then -superstition and stupidity reign instead of right and reason. Never -will our government improve until it casts off the fetters of the -Church and raises the views of the citizens on man and the world to a -higher level by a general scientific education. That does not raise -the question of any special form of constitution. Whether a monarchy -or a republic be preferable, whether the constitution should be -aristocratic or democratic, are subordinate questions in comparison -with the supreme question: Shall the modern civilized state be -spiritual or secular? Shall it be _theocratic_--ruled by the irrational -formulæ of faith and by clerical despotism--or _nomocratic_--under the -sovereignty of rational laws and civic right? The first task is to -kindle a rational interest in our youth, and to uplift our citizens -and free them from superstition. That can only be achieved by a timely -reform of our schools. - -Our education of the young is no more in harmony with modern scientific -progress than our legal and political world. Physical science, which -is so much more important than all other sciences, and which, properly -understood, really embraces all the so-called moral sciences, is still -regarded as a mere accessory in our schools, if not treated as the -Cinderella of the curriculum. Most of our teachers still give the -most prominent place to that dead learning which has come down from -the cloistral schools of the Middle Ages. In the front rank we have -grammatical gymnastics and an immense waste of time over a "thorough -knowledge" of classics and of the history of foreign nations. Ethics, -the most important object of practical philosophy, is entirely -neglected, and its place is usurped by the ecclesiastical creed. Faith -must take precedence over knowledge--not that scientific faith which -leads to a monistic religion, but the irrational superstition that -lays the foundation of a perverted Christianity. The valuable teaching -of modern cosmology and anthropology, of biology and evolution, is -most inadequately imparted, if not entirely unknown, in our higher -schools; while the memory is burdened with a mass of philological and -historical facts which are utterly useless, either from the point of -view of theoretical education or for the practical purposes of life. -Moreover, the antiquated arrangements and the distribution of faculties -in the universities are just as little in harmony with the point we -have reached in monistic science as the curriculum of the primary and -secondary schools. - -The climax of the opposition to modern education and its foundation, -advanced natural philosophy, is reached, of course, in the Church. We -are not speaking here of ultramontane papistry, nor of the orthodox -evangelical tendencies, which do not fall far short of it in ignorance -and in the crass superstition of their dogmas. We are imagining -ourselves for the moment to be in the church of a liberal Protestant -minister, who has a good average education, and who finds room for -"the rights of reason" by the side of his faith. There, besides -excellent moral teaching, which is in perfect harmony with our own -monistic ethics, and humanitarian discussion of which we cordially -approve, we hear ideas on the nature of God, of the world, of man, and -of life which are directly opposed to all scientific experience. It -is no wonder that physicists and chemists, doctors and philosophers, -who have made a thorough study of nature, refuse a hearing to such -preachers. Our theologians and our politicians are just as ignorant -as our philosophers and our jurists of that elementary knowledge of -nature which is based on the monistic theory of evolution, and which is -already far exceeded in the triumph of our modern learning. - -From this opposition, which we can only briefly point out at present, -there arise grave conflicts in our modern life which urgently demand -a settlement. Our modern education, the outcome of our great advance -in knowledge, has a claim upon every department of public and private -life; it would see humanity raised, by the instrumentality of -reason, to that higher grade of culture, and, consequently, to that -better path towards happiness which has been opened out to us by the -progress of modern science. That aim, however, is vigorously opposed -by the influential parties who would detain the mind in the exploded -views of the Middle Ages with regard to the most important problems -of life; they linger in the fold of traditional dogma, and would -have reason prostrate itself before their "higher revelation." That -is the condition of things, to a very large extent, in theology and -philosophy, in sociology and jurisprudence. It is not that the motives -of the latter are to be attributed, as a rule, to pure self-interest; -they spring partly from ignorance of the facts, and partly from an -indolent acquiescence in tradition. The most dangerous of the three -great enemies of reason and knowledge is not malice; but ignorance, or, -perhaps, indolence. The gods themselves still strive in vain against -these two latter influences when they have happily vanquished the first. - -One of the main supports of that reactionary system is still what -we may call "anthropism." I designate by this term "that powerful -and world-wide group of erroneous opinions which opposes the human -organism to the whole of the rest of nature, and represents it to be -the preordained end of the organic creation, an entity essentially -distinct from it, a godlike being." Closer examination of this group of -ideas shows it to be made up of three different dogmas, which we may -distinguish as the _anthropocentric_, the _anthropomorphic_, and the -_anthropolatrous_.[4] - -I. The _anthropocentric_ dogma culminates in the idea that man -is the preordained centre and aim of all terrestrial life--or, in -a wider sense, of the whole universe. As this error is extremely -conducive to man's interest, and as it is intimately connected with the -creation-myth of the three great Mediterranean religions, and with the -dogmas of the Mosaic, Christian, and Mohammedan theologies, it still -dominates the greater part of the civilized world. - -II. The _anthropomorphic_ dogma is likewise connected with the -creation-myth of the three aforesaid religions, and of many others. It -likens the creation and control of the world by God to the artificial -creation of a talented engineer or mechanic, and to the administration -of a wise ruler. God, as creator, sustainer, and ruler of the world, -is thus represented after a purely human fashion in his thought and -work. Hence it follows, in turn, that man is godlike. "God made man -to His own image and likeness." The older, naïve mythology is pure -"homotheism," attributing human shape, flesh, and blood to the gods. -It is more intelligible than the modern mystic theosophy that adores -a personal God as an invisible--properly speaking, gaseous--being, -yet makes him think, speak, and act in human fashion; it gives us the -paradoxical picture of a "gaseous vertebrate." - -III. The _anthropolatric_ dogma naturally results from this comparison -of the activity of God and man; it ends in the apotheosis of the human -organism. A further result is the belief in the personal immortality of -the soul, and the dualistic dogma of the twofold nature of man, whose -"immortal soul" is conceived as but the temporary inhabitant of the -mortal frame. Thus these three anthropistic dogmas, variously adapted -to the respective professions of the different religions, came at -length to be vested with an extraordinary importance, and proved the -source of the most dangerous errors. The anthropistic view of the world -which springs from them is in irreconcilable opposition to our monistic -system; indeed, it is at once disproved by our new cosmological -perspective. - -Not only the three anthropistic dogmas, but many other notions of the -dualistic philosophy and orthodox religion, are found to be untenable -as soon as we regard them critically from the cosmological perspective -of our monistic system. We understand by that the comprehensive view -of the universe which we have from the highest point of our monistic -interpretation of nature. From that stand-point we see the truth of the -following "cosmological theorems," most of which, in our opinion, have -already been amply demonstrated: - -(1) The universe, or the cosmos, is eternal, infinite, and illimitable. -(2) Its substance, with its two attributes (matter and energy), fills -infinite space, and is in eternal motion. (3) This motion runs on -through infinite time as an unbroken development, with a periodic -change from life to death, from evolution to devolution. (4) The -innumerable bodies which are scattered about the space-filling ether -all obey the same "law of substance;" while the rotating masses slowly -move towards their destruction and dissolution in one part of space -others are springing into new life and development in other quarters -of the universe. (5) Our sun is one of these unnumbered perishable -bodies, and our earth is one of the countless transitory planets that -encircle them. (6) Our earth has gone through a long process of cooling -before water, in liquid form (the first condition of organic life), -could settle thereon. (7) The ensuing biogenetic process, the slow -development and transformation of countless organic forms, must have -taken many millions of years--considerably over a hundred.[5] (8) Among -the different kinds of animals which arose in the later stages of the -biogenetic process on earth the vertebrates have far outstripped all -other competitors in the evolutionary race. (9) The most important -branch of the vertebrates, the mammals, were developed later (during -the triassic period) from the lower amphibia and the reptilia. (10) The -most perfect and most highly developed branch of the class mammalia is -the order of primates, which first put in an appearance, by development -from the lowest prochoriata, at the beginning of the Tertiary -period--at least three million years ago. (11) The youngest and most -perfect twig of the branch primates is man, who sprang from a series of -manlike apes towards the end of the Tertiary period. (12) Consequently, -the so-called "history of the world"--that is, the brief period of a -few thousand years which measures the duration of civilization--is an -evanescently short episode in the long course of organic evolution, -just as this, in turn, is merely a small portion of the history of -our planetary system; and as our mother-earth is a mere speck in the -sunbeam in the illimitable universe, so man himself is but a tiny grain -of protoplasm in the perishable framework of organic nature. - -Nothing seems to me better adapted than this magnificent cosmological -perspective to give us the proper standard and the broad outlook -which we need in the solution of the vast enigmas that surround us. -It not only clearly indicates the true place of man in nature, but it -dissipates the prevalent illusion of man's supreme importance, and -the arrogance with which he sets himself apart from the illimitable -universe, and exalts himself to the position of its most valuable -element. This boundless presumption of conceited man has misled him -into making himself "the image of God," claiming an "eternal life" for -his ephemeral personality, and imagining that he possesses unlimited -"freedom of will." The ridiculous imperial folly of Caligula is but -a special form of man's arrogant assumption of divinity. Only when -we have abandoned this untenable illusion, and taken up the correct -cosmological perspective, can we hope to reach the solution of the -"riddles of the universe." - -The uneducated member of a civilized community is surrounded with -countless enigmas at every step, just as truly as the savage. Their -number, however, decreases with every stride of civilization and of -science; and the monistic philosophy is ultimately confronted with but -one simple and comprehensive enigma--the "problem of substance." Still, -we may find it useful to include a certain number of problems under -that title. In the famous speech which Emil du Bois-Reymond delivered -in 1880, in the Leibnitz session of the Berlin Academy of Sciences, -he distinguished seven world-enigmas, which he enumerated as follows: -(1) The nature of matter and force. (2) The origin of motion. (3) The -origin of life. (4) The (apparently preordained) orderly arrangement -of nature. (5) The origin of simple sensation and consciousness. (6) -Rational thought, and the origin of the cognate faculty, speech. (7) -The question of the freedom of the will. Three of these seven enigmas -are considered by the orator of the Berlin Academy to be entirely -transcendental and insoluble--they are the first, second, and fifth; -three others (the third, fourth, and sixth) he considers to be capable -of solution, though extremely difficult; as to the seventh and last -"world-enigma," the freedom of the will, which is the one of the -greatest practical importance, he remains undecided. - -As my monism differs materially from that of the Berlin orator, and as -his idea of the "seven great enigmas" has been very widely accepted, -it may be useful to indicate their true position at once. In my -opinion, the three transcendental problems (1, 2, and 5) are settled -by our conception of substance (_vide_ chap. xii.); the three which -he considers difficult, though soluble, (3, 4, and 6), are decisively -answered by our modern theory of evolution; the seventh and last, the -freedom of the will, is not an object for critical, scientific inquiry -at all, for it is a pure dogma, based on an illusion, and has no real -existence. - -The means and methods we have chosen for attaining the solution of the -great enigma do not differ, on the whole, from those of all purely -scientific investigation--firstly, experience; secondly, inference. -Scientific experience comes to us by observation and experiment, which -involve the activity of our sense-organs in the first place, and, -secondly, of the inner sense-centres in the cortex of the brain. The -microscopic elementary organs of the former are the sense-cells; of the -latter, groups of ganglionic cells. The experiences which we derive -from the outer world by these invaluable instruments of our mental life -are then moulded into ideas by other parts of the brain, and these, -in their turn, are united in a chain of reasoning by association. The -construction of this chain may take place in two different ways, which -are, in my opinion, equally valuable and indispensable: _induction_ -and _deduction_. The higher cerebral operations, the construction -of complicated chains of reasoning, abstraction, the formation of -concepts, the completion of the perceptive faculty by the plastic -faculty of the imagination--in a word, consciousness, thought, and -speculation--are functions of the ganglionic cells of the cortex of the -brain, just like the preceding simpler mental functions. We unite them -all in the supreme concept of _reason_.[6] - -By reason only can we attain to a correct knowledge of the world and a -solution of its great problems. Reason is man's highest gift, the only -prerogative that essentially distinguishes him from the lower animals. -Nevertheless, it has only reached this high position by the progress of -culture and education, by the development of knowledge. The uneducated -man and the savage are just as little (or just as much) "rational" -as our nearest relatives among the mammals (apes, dogs, elephants, -etc.). Yet the opinion still obtains in many quarters that, besides -our godlike reason, we have two further (and even surer!) methods of -receiving knowledge--emotion and revelation. We must at once dispose -of this dangerous error. Emotion has nothing whatever to do with the -attainment of truth. That which we prize under the name of "emotion" -is an elaborate activity of the brain, which consists of feelings of -like and dislike, motions of assent and dissent, impulses of desire and -aversion. It may be influenced by the most diverse activities of the -organism, by the cravings of the senses and the muscles, the stomach, -the sexual organs, etc. The interests of truth are far from promoted -by these conditions and vacillations of emotion; on the contrary, such -circumstances often disturb that reason which alone is adapted to the -pursuit of truth, and frequently mar its perceptive power. No cosmic -problem is solved, or even advanced, by the cerebral function we call -emotion. And the same must be said of the so-called "revelation," and -of the "truths of faith" which it is supposed to communicate; they are -based entirely on a deception, consciously or unconsciously, as we -shall see in the sixteenth chapter. - -We must welcome as one of the most fortunate steps in the direction -of a solution of the great cosmic problems the fact that of recent -years there is a growing tendency to recognize the two paths which -alone lead thereto--_experience_ and _thought_, or _speculation_--to -be of equal value, and mutually complementary. Philosophers have come -to see that pure speculation--such, for instance, as Plato and Hegel -employed for the construction of their _idealist_ systems--does not -lead to knowledge of reality. On the other hand, scientists have been -convinced that mere experience--such as Bacon and Mill, for example, -made the basis of their _realist_ systems--is insufficient of itself -for a complete philosophy. For these two great paths of knowledge, -sense-experience and rational thought, are two distinct cerebral -functions; the one is elaborated by the sense-organs and the inner -sense-centres, the other by the thought-centres, the great "centres -of association in the cortex of the brain," which lie between the -sense-centres. (Cf. cc. vii. and x.) True knowledge is only acquired -by combining the activity of the two. Nevertheless, there are still -many philosophers who would construct the world out of their own -inner consciousness, and who reject our empirical science precisely -because they have no knowledge of the real world. On the other hand, -there are many scientists who still contend that the sole object of -science is "the knowledge of facts, the objective investigation of -isolated phenomena"; that "the age of philosophy" is past, and science -has taken its place.[7] This one-sided over-estimation of experience -is as dangerous an error as the converse exaggeration of the value of -speculation. Both channels of knowledge are mutually indispensable. -The greatest triumphs of modern science--the cellular theory, the -dynamic theory of heat, the theory of evolution, and the law of -substance--are _philosophic achievements_; not, however, the fruit of -pure speculation, but of an antecedent experience of the widest and -most searching character. - -At the commencement of the nineteenth century the great idealistic -poet, Schiller, gave his counsel to both groups of combatants, the -philosophers and the scientists: - - "Does strife divide your efforts--no union bless your toil? - Will truth e'er be delivered if ye your forces rend?" - -Since then the situation has, happily, been profoundly modified; while -both schools, in their different paths, have pressed onward towards the -same high goal, they have recognized their common aspiration, and they -draw nearer to a knowledge of the truth in mutual covenant. At the end -of the nineteenth century we have returned to that monistic attitude -which our greatest realistic poet, Goethe, had recognized from its very -commencement to be alone correct and fruitful.[8] - -All the different philosophical tendencies may, from the point of -view of modern science, be ranged in two antagonistic groups; they -represent either a _dualistic_ or a _monistic_ interpretation of -the cosmos. The former is usually bound up with teleological and -idealistic dogmas, the latter with mechanical and realistic theories. -Dualism, in the widest sense, breaks up the universe into two entirely -distinct substances--the material world and an immaterial God, who -is represented to be its creator, sustainer, and ruler. Monism, on -the contrary (likewise taken in its widest sense), recognizes one -sole substance in the universe, which is at once "God and nature"; -body and spirit (or matter and energy) it holds to be inseparable. -The extramundane God of dualism leads necessarily to theism; and the -intra-mundane God of the monist leads to pantheism. - -The different ideas of _monism_ and _materialism_, and likewise -the essentially distinct tendencies of theoretical and practical -materialism, are still very frequently confused. As this and other -similar cases of confusion of ideas are very prejudicial, and give rise -to innumerable errors, we shall make the following brief observations, -in order to prevent misunderstanding: - -I. Pure monism is identical neither with the theoretical materialism -that denies the existence of spirit, and dissolves the world into a -heap of dead atoms, nor with the theoretical spiritualism (lately -entitled "energetic" spiritualism by Ostwald) which rejects the notion -of matter, and considers the world to be a specially arranged group of -"energies" or immaterial natural forces. - -II. On the contrary, we hold, with Goethe, that "matter cannot exist -and be operative without spirit, nor spirit without matter." We -adhere firmly to the pure, unequivocal monism of Spinoza: Matter, or -infinitely extended substance, and spirit (or energy), or sensitive and -thinking substance, are the two fundamental attributes or principal -properties of the all-embracing divine essence of the world, the -universal substance. (Cf. chap. xii.) - - - - -CHAPTER II - -OUR BODILY FRAME - - Fundamental Importance of Anatomy--Human Anatomy--Hippocrates, - Aristotle, Galen, Vesalius--Comparative Anatomy--Georges - Cuvier--Johannes Müller--Karl Gegenbaur--Histology--The Cellular - Theory--Schleiden and Schwann--Kölliker--Virchow--Man a - Vertebrate, a Tetrapod, a Mammal, a Placental, a Primate--Prosimiæ - and Simiæ--The Catarrhinæ--Papiomorphic and Anthropomorphic - Apes--Essential Likeness of Man and the Ape in Corporal Structure - - -All biological research, all investigation into the forms and vital -activities of organisms, must first deal with the visible body, in -which the morphological and physiological phenomena are observed. This -fundamental rule holds good for man just as much as for all other -living things. Moreover, the inquiry must not confine itself to mere -observation of the outer form; it must penetrate to the interior, and -study both the general plan and the minute details of the structure. -The science which pursues this fundamental investigation in the -broadest sense is anatomy. - -The first stimulus to an inquiry into the human frame arose, naturally, -in medicine. As it was usually practised by the priests in the older -civilizations, we may assume that these highest representatives of -the education of the time had already acquired a certain amount -of anatomical knowledge two thousand years before Christ, or even -earlier. We do not, however, find more exact observations, founded -on the dissection of mammals, and applied, by analogy, to the human -frame, until we come to the Greek scientists of the sixth and fifth -centuries before Christ--Empedocles (of Agrigentum) and Democritus -(of Abdera), and especially the most famous physician of classic -antiquity, Hippocrates (of Cos). It was from these and other sources -that the great Aristotle, the renowned "father of natural history," -equally comprehensive as investigator and philosopher, derived his -first knowledge. After him only one anatomist of any consequence is -found in antiquity, the Greek physician Claudius Galenus (of Pergamus), -who developed a wealthy practice in Rome in the second century after -Christ, under the Emperor Marcus Aurelius. All these ancient anatomists -acquired their knowledge, as a rule, not by the dissection of the human -body itself--which was then sternly forbidden--but by a study of the -bodies of the animals which most closely resembled man, especially the -apes; they were all, indeed, comparative anatomists. - -The triumph of Christianity and its mystic theories meant retrogression -to anatomy, as it did to all the other sciences. The popes were -resolved above all things to detain humanity in ignorance; they rightly -deemed a knowledge of the human organism to be a dangerous source -of enlightenment as to our true nature. During the long period of -thirteen centuries the writings of Galen were almost the only source -of human anatomy, just as the works of Aristotle were for the whole -of natural history. It was not until the sixteenth century, when the -spiritual tyranny of the papacy was broken by the Reformation, and the -geocentric theory, so intimately connected with papal doctrine, was -destroyed by the new cosmic system of Copernicus, that the knowledge -of the human frame entered upon a new period of progress. The great -anatomists, Vesalius (of Brussels), and Eustachius and Fallopius -(of Modena), advanced the knowledge of our bodily structure so much -by their own thorough investigations that little remained for their -numerous followers to do, with regard to the more obvious phenomena, -except the substantiation of details. Andreas Vesalius, as courageous -as he was talented and indefatigable, was the pioneer of the movement; -he completed in his twenty-eighth year (1543) that great and systematic -work _De humani corporis fabrica_; he gave to the whole of human -anatomy a new and independent scope and a more solid foundation. On -that account he was, at a later date, at Madrid--where he was physician -to Charles V. and Philip II.--condemned to death by the Inquisition as -a magician. He only escaped by undertaking a pilgrimage to Jerusalem; -in returning he suffered shipwreck on the Isle of Zante, and died there -in misery and destitution. - -The great merit of the nineteenth century, as far as our knowledge of -the human frame is concerned, lies in the founding of two new lines -of research of immense importance--comparative anatomy and histology, -or microscopic anatomy. The former was intimately associated with -human anatomy from the very beginning; indeed, it had to supply the -place of the latter so long because the dissection of human corpses -was a crime visited with capital punishment--that was the case even -in the fifteenth century! But the many anatomists of the next three -centuries devoted themselves mainly to a more accurate study of the -human organism. The elaborate science which we now call comparative -anatomy was born in the year 1803, when the great French zoologist -Georges Cuvier (a native of Mömpelgard, in Alsace) published his -profound _Leçons sur l'anatomie comparée_, and endeavored to formulate, -for the first time, definite laws as to the organism of man and the -beasts. While his predecessors--among whom was Goethe in 1790--had -mainly contented themselves with comparing the skeleton of man with -those of other animals, Cuvier's broader vision took in the whole -of the animal organization. He distinguished therein four great and -mutually independent types: Vertebrata, Articulata, Mollusca, and -Radiata. This advance was of extreme consequence for our "question -of all questions," since it clearly brought out the fact that man -belonged to the vertebral type, and differed fundamentally from all -the other types. It is true that the keen-sighted Linné had already, -in his _Systema Natuae_, made a great step in advance by assigning -man a definite place in the class of mammals; he had even drawn up -the three groups of half-apes, apes, and men (_Lemur_, _simia_, and -_homo_) in the order of primates. But his keen, systematic mind was -not furnished with that profound empirical foundation, supplied by -comparative anatomy, which Cuvier was the first to attain. Further -developments were added by the great comparative anatomists of our own -century--Friedrich Meckel (Halle), Johannes Müller (Berlin), Richard -Owen, T. Huxley, and Karl Gegenbaur (Jena, subsequently Heidelberg). -The last-named, in applying the evolutionary theory, which Darwin had -just established, to comparative anatomy, raised his science to the -front rank of biological studies. The numerous comparative anatomical -works of Gegenbaur are, like his well-known _Manual of Human Anatomy_, -equally distinguished by a thorough empirical acquaintance with their -immense multitudes of facts, and by a comprehensive control of his -material, and its philosophic appreciation in the evolutionary sense. -His recent _Comparative Anatomy of the Vertebrata_ establishes the -solid foundation on which our conviction of the vertebral character of -man in every aspect is chiefly based. - -Microscopic anatomy has been developed, in the course of the present -century, in a very different fashion from comparative anatomy. At -the beginning of the century (1802) a French physician, Bichat, made -an attempt to dissect the organs of the human body into their finer -constituents by the aid of the microscope, and to show the connection -of these various _tissues_ (_hista_, or _tela_). This first attempt -led to little result, because the scientist was ignorant of the one -common element of all the different tissues. This was first discovered -(1838) in the shape of the _cell_, in the plant world, by Matthias -Schleiden, and immediately afterwards proved to be the same in the -animal world by Theodor Schwann, the pupil and assistant of Johannes -Müller at Berlin. Two other distinguished pupils of this great master, -who are still living, Albert Kölliker and Rudolph Virchow, took up -the cellular theory, and the theory of tissues which is founded on -it, in the sixties, and applied them to the human organism in all its -details, both in health and disease; they proved that, in man and -all other animals, every tissue is made up of the same microscopic -particles, the _cells_, and these "elementary organisms" are the real, -self-active citizens which, in combinations of millions, constitute -the "cellular state," our body. All these cells spring from one simple -cell, the _cytula_, or impregnated ovum, by continuous subdivision. -The general structure and combination of the tissues are the same in -man as in the other vertebrates. Among these the mammals, the youngest -and most highly developed class take precedence, in virtue of certain -special features which were acquired late. Such are, for instance, the -microscopic texture of the hair, of the glands of the skin, and of the -breasts, and the corpuscles of the blood, which are quite peculiar to -mammals, and different from those of the other vertebrates; man, even -in these finest histological relations, is a _true mammal_. - -The microscopic researches of Albert Kölliker and Franz Leydig (at -Würzburg) not only enlarged our knowledge of the finer structure of man -and the beasts in every direction, but they were especially important -in the light of their connection with the evolution of the cell and -the tissue; they confirmed the great theory of Carl Theodor Siebold -(1845) that the lowest animals, the Infusoria and the Rhizopods, are -unicellular organisms. - -Our whole frame, both in its general plan and its detailed structure, -presents the characteristic type of the vertebrates. This most -important and most highly developed group in the animal world was -first recognized in its natural unity in 1801 by the great Lamarck; -he embraced under that title the four higher animal groups of -Linné--mammals, birds, amphibia, and fishes. To these he opposed the -two lower classes, insects and worms, as invertebrates. Cuvier (1812) -established the unity of the vertebrate type on a firmer basis by -his comparative anatomy. It is quite true that all the vertebrates, -from the fish up to man, agree in every essential feature; they all -have a firm internal skeleton, a framework of cartilage and bone, -consisting principally of a vertebral column and a skull; the advanced -construction of the latter presents many variations, but, on the whole, -all may be reduced to the same fundamental type. Further, in all -vertebrates the "organ of the mind," the central nervous system, in -the shape of a spinal cord and a brain, lies at the back of this axial -skeleton. Moreover, what we said of its bony environment, the skull, -is also true of the brain--the instrument of consciousness and all the -higher functions of the mind; its construction and size present very -many variations in detail, but its general characteristic structure -remains always the same. - -We meet the same phenomenon when we compare the rest of our organs with -those of the other vertebrates; everywhere, in virtue of heredity, -the original plan and the relative distribution of the organs remain -the same, although, through adaptation to different environments, -the size and the structure of particular sections offer considerable -variation. Thus we find that in all cases the blood circulates in -two main blood-vessels, of which one--the aorta--passes over the -intestine, and the other--the principal vein--passes underneath, and -that by the broadening out of the latter in a very definite spot a -heart has arisen; this "ventral heart" is just as characteristic of all -vertebrates as the "dorsal heart" is of the articulata and mollusca. -Equally characteristic of all vertebrates is the early division of -the intestinal tube into a "head-gut" (or gill-gut), which serves in -respiration, and a "body-gut" (or liver-gut), which co-operates with -the liver in digestion; so are, likewise, the ramification of the -muscular system, the peculiar structure of the urinary and sexual -organs, and so forth. In all these anatomical relations _man is a true -vertebrate_. - -Aristotle gave the name of four-footed, or tetrapoda, to all the higher -warm-blooded animals which are distinguished by the possession of two -pairs of legs. The category was enlarged subsequently, and its title -changed into the Latin "quadrupeda," when Cuvier proved that even -"two-legged" birds and men are really "four-footed"; he showed that the -internal skeleton of the four legs in all the higher land-vertebrates, -from the amphibia up to man, was originally constructed after the same -pattern out of a definite number of members. The "arm" of man and the -"wing" of bats and birds have the same typical skeleton as the foreleg -of the animals which are conspicuously "four-footed." - -The anatomical unity of the fully developed skeleton in the four limbs -of all tetrapods is very important. In order to appreciate it fully -one has only to compare carefully the skeleton of a salamander or a -frog with that of a monkey or a man. One perceives at once that the -humeral zone in front and the pelvic zone behind are made up of the -same principal parts as in the rest of the quadrupeds. We find in all -cases that the first section of the leg proper consists of one strong -marrow-bone (the _humerus_, in the forearm; the _femur_, behind); -the second part, on the contrary, originally always consists of two -bones (the _ulna_ and _radius_, in front; the _fibula_ and _tibia_, -behind). When we further compare the developed structure of the foot -proper we are surprised to find that the small bones of which it is -made up are also similarly arranged and distributed in every case: in -the front limb the three groups of bones of the forefoot (or "hand") -correspond in all classes of the tetrapoda: (1) the _carpus_, (2) -the _metacarpus_, (3) the five fingers (_digiti anteriores_); in the -rear limb, similarly, we have always the same three osseous groups of -the hind foot: (1) the _tarsus_, (2) the _metatarsus_, and (3) the -five toes (_digiti posteriores_). It was a very difficult task to -reduce all these little bones to one primitive type, and to establish -the equivalence (or homology) of the separate parts in all cases; -they present extreme variations of form and construction in detail, -sometimes being partly fused together and losing their individuality. -This great task was first successfully achieved by the most eminent -comparative anatomist of our day, Karl Gegenbaur. He pointed out, -in his _Researches into the Comparative Anatomy of the Vertebrata_ -(1864), how this characteristic "five-toed leg" of the land tetrapods -originally (not before the Carboniferous period) arose out of the -radiating fin (the breast-fin, or the belly-fin) of the ancient -fishes. He had also, in his famous _Researches into the Skull of the -Vertebrata_ (1872), deduced the younger skull of the tetrapods from the -oldest cranial form among the fishes, that of the shark. - -It is especially remarkable that the original number of the toes (five) -on each of the four feet, which first appeared in the old amphibia -of the Carboniferous period, has, in virtue of a strict heredity, -been preserved even to the present day in man. Also, naturally and -harmoniously, the typical construction of the joints, ligaments, -muscles, and nerves of the two pairs of legs has, in the main, remained -the same as in the rest of the "four-footed." In all these important -relations _man is a true tetrapod_. - -The mammals are the youngest and most advanced class of the vertebrates. -It is true they are derived from the older class of amphibia, like -birds and reptiles: yet they are distinguished from all the other -tetrapods by a number of very striking anatomical features. Externally, -there is the clothing of the skin with hair, and the possession of -two kinds of skin glands--the sweat glands and the sebaceous glands. -A local development of these glands on the abdominal skin gave -rise (probably during the Triassic period) to the organ which is -especially characteristic of the class, and from which it derives its -name--the _mammarium_. This important instrument of lactation is made -up of milk glands (_mammae_) and the "mammar-pouches" (folds of the -abdominal skin); in its development the teats appear, through which -the young mammal sucks its mother's milk. In internal structure the -most remarkable feature is the possession of a complete diaphragm, a -muscular wall which, in all mammals--and _only_ in mammals--separates -the thoracic from the abdominal cavity; in all other vertebrates -there is no such separation. The skull of mammals is distinguished -by a number of remarkable formations, especially in the maxillary -apparatus (the upper and lower jaws, and the temporal bones). Moreover, -the brain, the olfactory organ, the heart, the lungs, the internal -and external sexual organs, the kidneys, and other parts of the body -present special peculiarities, both in general and detailed structure, -in the mammals; all these, taken collectively, point unequivocally -to an early derivation of the mammals from the older groups of the -reptiles and amphibia, which must have taken place, at the latest, in -the Triassic period--at least twelve million years ago! In all these -important characteristics _man is a true mammal_. - -The numerous orders (12-33) which modern systematic zoology -distinguishes in the class of mammals had been arranged in 1816 -(by Blainville) in three natural groups, which still hold good as -sub-classes: (1) the monotrema, (2) the marsupialia, and (3) the -placentalia. These three sub-classes not only differ in the important -respect of bodily structure and development, but they correspond, also, -to three different historical stages in the formation of the class, -as we shall see later on. The monotremes of the Triassic period were -followed by the marsupials of the Jurassic, and these by the placentals -of the Cretaceous. Man belongs to this, the youngest, sub-class; for -he presents in his organization all the features which distinguish -the placentals from the marsupials and the still older monotremes. -First of all, there is the peculiar organ which gives a name to the -placentals--the _placenta_. It serves the purpose of nourishing the -young mammal embryo for a long time during its enclosure in the -mother's womb; it consists of blood-bearing tufts which grow out of the -chorion surrounding the embryo, and penetrate corresponding cavities in -the mucous membrane of the maternal uterus; the delicate skin between -the two structures is so attenuated in this spot that the nutriment in -the mother's blood can pass directly into the blood of the child. This -excellent contrivance for nourishing the embryo, which makes its first -appearance at a somewhat late date, gives the foetus the opportunity -of a longer maintenance and a higher development in the protecting -womb; it is wanting in the _implacentalia_, the two older sub-classes -of the marsupials and the monotremes. There are, likewise, other -anatomical features, particularly the higher development of the brain -and the absence of the marsupial bone, which raise the placentals above -all their implacental ancestors. In all these important particulars -_man is a true placental_. - -The very varied sub-class of the placentals has been recently -subdivided into a great number of orders; they are usually put at from -ten to sixteen, but when we include the important extinct forms which -have been recently discovered the number runs up to from twenty to -twenty-six. In order to facilitate the study of these numerous orders, -and to obtain a deeper insight into their kindred construction, it -is very useful to form them into great natural groups, which I have -called "legions." In my latest attempt[9] to arrange the advanced -system of placentals in phylogenetic order I have substituted eight -of these legions for the twenty-six orders, and shown that these may -be reduced to four main groups. These, in turn, are traceable to one -common ancestral group of all the placentals, their fossil ancestors, -the _prochoriata_ of the Cretaceous period. These are directly -connected with the marsupial ancestors of the Jurassic period. We -will only specify here, as the most important living representatives -of these four main groups, the rodentia, the ungulata, the carnivora, -and the primates. To the legion of the primates belong the prosimiæ -(half-apes), the simiæ (real apes), and man. All the members of these -three orders agree in many important features, and are at the same -time distinguished by these features from the other twenty-three -orders of placentals. They are especially conspicuous for the length -of their bones, which were originally adapted to their arboreal manner -of life. Their hands and feet are five-fingered, and the long fingers -are excellently suited for grasping and embracing the branches of -trees; they are provided, either partially or completely, with nails, -but have no claws. The dentition is complete, containing all four -classes--incisors, canine, premolars, and molars. Primates are also -distinguished from all the other placentals by important features in -the special construction of the skull and the brain; and these are the -more striking in proportion to their development and the lateness of -their appearance in the history of the earth. In all these important -anatomical features our human organism agrees with that of all the -other primates: _man is a true primate_. - -An impartial and thorough comparison of the bodily structure of the -primates forces us to distinguish two orders in this most advanced -legion of the mammalia--half-apes (_prosimiae_ or _hemipitheci_) and -apes (_simiae_ or _pitheci_). The former seem in every respect to be -the lower and older, the latter to be the higher and younger order. The -womb of the half-ape is still double, or two-horned, as it is in all -the other mammals. In the true ape, on the contrary, the right and left -wombs have completely amalgamated; they blend into a pear-shaped womb, -which the human mother possesses besides the ape. In the skull of the -apes, just as in that of man, the orbits of the eyes are completely -separated from the temporal cavities by an osseous partition; in -the _prosimiae_ this is either entirely wanting or very imperfect. -Finally, the cerebrum of the _prosimia_ is either quite smooth or very -slightly furrowed, and proportionately small; that of the true ape is -much larger, and the gray bed especially, the organ of higher psychic -activity, is much more developed; the characteristic convolutions -and furrows appear on its surface exactly in proportion as the ape -approaches to man. In these and other important respects, particularly -in the construction of the face and the hands, _man presents all the -anatomical marks of a true ape_. - -The extensive order of apes was divided by Geoffroi, in 1812, into -two sub-orders, which are still universally accepted in systematic -zoology--New World and Old World monkeys, according to the hemisphere -they respectively inhabit. The American "New World" monkeys are called -_Platyrrhinae_ (flat-nosed); their nose is flat, and the nostrils -divergent, with a broad partition. The "Old World" monkeys, on the -contrary, are called collectively _Catarrhinae_ (narrow-nosed); their -nostrils point downward, like man's, and the dividing cartilage is -narrow. A further difference between the two groups is that the -tympanum is superficial in the _platyrrhinae_, but lies deeper, -inside the petrous bone, in the _catarrhinae_; in the latter a long -and narrow bony passage has been formed, while in the former it is -still short and wide, or even altogether wanting. Finally, we have a -much more important and decisive difference between the two groups in -the circumstance that all the Old World monkeys have the same teeth -as man--_i. e._, twenty deciduous and thirty-two permanent teeth -(two incisors, one canine, two premolars, and three molars in each -half of the jaw). The New World monkeys, on the other hand, have an -additional premolar in each half-jaw, or thirty-six teeth altogether. -The fact that these anatomical differences of the two simian groups -are universal and conspicuous, and that they harmonize with their -geographical distribution in the two hemispheres, fully authorizes -a sharp systematic division of the two, as well as the phylogenetic -conclusion that for a very long period (for more than a million years) -the two sub-orders have been developing quite independently of each -other in the western and eastern hemispheres. That is a most important -point in view of the genealogy of our race; for man bears all the marks -of a _true catarrhina_; he has descended from some extinct member of -this sub-order in the Old World. - -The numerous types of _catarrhinae_ which still survive in Asia and -Africa have been formed into two sections for some time--the tailed, -doglike apes (the _cynopitheci_) and the tailless, manlike apes (the -_anthropomorpha_). The latter are much nearer to man than the former, -not only in the absence of a tail and in the general build of the body -(especially of the head), but also on account of certain features -which are unimportant in themselves but very significant in their -constancy. The sacrum of the anthropoid ape, like that of man, is made -up of the fusion of five vertebræ; that of the _cynopithecus_ consists -of three (more rarely four) sacral vertebræ. The premolar teeth of -the _cynopitheci_ are greater in length than breadth; those of the -_anthropomorpha_ are broader than they are long; and the first molar -has four protuberances in the former, five in the latter. Furthermore, -the outer incisor of the lower jaw is broader than the inner one -in the manlike apes and man; in the doglike ape it is the smaller. -Finally, there is a special significance in the fact, established by -Selenka in 1890, that the anthropoid apes share with man the peculiar -structure of the discoid _placenta_, the _decidua reflexa_, and the -pedicle of the allantois. In fact, even a superficial comparison of -the bodily structure of the _anthropomorpha_ which still survive makes -it clear that both the Asiatic (the orang-outang and the gibbous ape) -and the African (the gorilla and chimpanzee) representatives of this -group are nearer to man in build than any of the _cynopitheci_. Under -the latter group we include the dog-faced papiomorpha, the baboon, -and the long-tailed monkey, at a very low stage. The anatomical -difference between these low papiomorpha and the most highly developed -anthropoid apes is greater in every respect, whatever organ we take -for comparison, than the difference between the latter and man. -This instructive fact was established with great penetration by the -anatomist Robert Hartmann, in his work on _The Anthropoid Apes_;[10] -he proposed to divide the order of _Simiae_ in a new way--namely, into -the two great groups of _primaria_ (man and the anthropoid ape) and the -_simiae_ proper, or _pitheci_ (the rest of the catarrhinæ and all the -platyrrhinæ). In any case, we have a clear proof of _the close affinity -of man and the anthropoid ape_. - -Thus comparative anatomy proves to the satisfaction of every -unprejudiced and critical student the significant fact that the body of -man and that of the anthropoid ape are not only peculiarly similar, but -they are practically one and the same in every important respect. The -same two hundred bones, in the same order and structure, make up our -inner skeleton; the same three hundred muscles effect our movements; -the same hair clothes our skin; the same groups of ganglionic cells -build up the marvellous structure of our brain; the same four chambered -heart is the central pulsometer in our circulation; the same thirty-two -teeth are set in the same order in our jaws; the same salivary, -hepatic, and gastric glands compass our digestive process; the same -reproductive organs insure the maintenance of our race. - -It is true that we find, on close examination, certain minor -differences in point of size and shape in most of the organs of man -and the ape; but we discover the same, or similar, differences -between the higher and lower races of men, when we make a careful -comparison--even, in fact, in a minute comparison of the various -individuals of our own race. We find no two persons who have exactly -the same size and form of nose, ears, eyes, and so forth. One has -only to compare attentively these special features in many different -persons in any large company to convince one's self of the astonishing -diversity of their construction and the infinite variability of -specific forms. Not infrequently even two sisters are so much unlike -as to make their origin from the same parents almost incredible. Yet -all these individual variations do not weaken the significance of the -fundamental similarity of structure; they are traceable to certain -minute differences in the growth of the individual features. - - - - -CHAPTER III - -OUR LIFE - - Development of Physiology in Antiquity and the Middle Ages: - Galen--Experiment and Vivisection--Discovery of the Circulation - of the Blood by Harvey--Vitalism: Haller--Teleological and - Vitalistic Conception of Life--Mechanical and Monistic View - of the Physiological Processes--Comparative Physiology in the - Nineteenth Century: Johannes Müller--Cellular Physiology: Max - Verworn--Cellular Pathology: Virchow--Mammal Physiology--Similarity - of all Vital Activity in Man and the Ape - - -It is only in the nineteenth century that our knowledge of human life -has attained the dignity of a genuine, independent science; during the -course of the century it has developed into one of the highest, most -interesting, and most important branches of knowledge. This "science -of the vital functions," physiology, had, it is true, been regarded -at a much earlier date as a desirable, if not a necessary, condition -of success in medical treatment, and had been constantly associated -with anatomy, the science of the structure of the body. But it was -only much later, and much more slowly, than the latter that it could -be thoroughly studied, as it had to contend with much more serious -difficulties. - -The idea of life, as the opposite of death, naturally became the -subject of speculation at a very early age. In the living man, just -as in other living animals, there were certain peculiar changes, -especially movements, which were wanting in lifeless nature: -spontaneous locomotion, the beat of the heart, the drawing of the -breath, speech, and so forth. But the discrimination of such "organic -movements" from similar phenomena in inorganic bodies was by no means -easy, and was frequently impossible; the flowing stream, the flickering -flame, the rushing wind, the falling rock, seemed to man to exhibit -the same movements. It was quite natural that primitive man should -attribute an independent life to these "dead" bodies. He knew no more -of the real sources of movement in the one case than in the other. - -We find the earliest scientific observations on the nature of man's -vital functions (as well as on his structure) in the Greek natural -philosophers and physicians of the sixth and fifth centuries before -Christ. The best collection of the physiological facts which were known -at that time is to be found in the _Natural History_ of Aristotle; a -great number of his assertions were probably taken from Democritus -and Hippocrates. The school of the latter had already made attempts -to explain the mystery; it postulated as the ultimate source of life -in man and the beasts a volatile "spirit of life" (Pneuma); and -Erasistratus (280 B.C.) already drew a distinction between the lower -and the higher "spirit of life," the _pneuma zoticon_ in the heart and -the _pneuma psychicon_ in the brain. - -The credit of gathering these scattered truths into unity, and of -making the first attempt at a systematic physiology, belongs to the -great Greek physician Galen; we have already recognized in him the -first great anatomist of antiquity (cf. p. 23). In his researches -into the organs of the body he never lost sight of the question of -their vital activity, their functions; and even in this direction he -proceeded by the same comparative method, taking for his principal -study the animals which approach nearest to man. Whatever he learned -from these he applied directly to man. He recognized the value of -physiological experiment; in his vivisection of apes, dogs, and -swine he made a number of interesting experiments. Vivisection has -been made the object of a violent attack in recent years, not only -by the ignorant and narrow-minded, but by theological enemies of -knowledge and by perfervid sentimentalists; it is, however, one of the -_indispensable_ methods of research into the nature of life, and has -given us invaluable information on the most important questions. This -was recognized by Galen seventeen hundred years ago. - -Galen reduces all the different functions of the body to three -groups, which correspond to the three forms of the _pneuma_, or vital -spirit. The _pneuma psychicon_--the soul--which resides in the brain -and nerves, is the cause of thought, sensation, and will (voluntary -movement); the _pneuma zoticon_--the heart--is responsible for the beat -of the heart, the pulse, and the temperature; the _pneuma physicon_, -seated in the liver, is the source of the so-called vegetative -functions, digestion and assimilation, growth and reproduction. -He especially emphasized the renewal of the blood in the lungs, -and expressed a hope that we should some day succeed in isolating -the permanent element in the atmosphere--the _pneuma_, as he calls -it--which is taken into the blood in respiration. More than fifteen -centuries elapsed before this _pneuma_--oxygen--was discovered by -Lavoisier. - -In human physiology, as well as in anatomy, the great system of Galen -was for thirteen centuries the _Codex aureus_, the inviolable source of -all knowledge. The influence of Christianity, so fatal to scientific -culture, raised the same insuperable obstacles in this as in every -other branch of secular knowledge. Not a single scientist appeared -from the third to the sixteenth century who dared to make independent -research into man's vital activity, and transcend the limits of the -Galenic system. It was not until the sixteenth century that experiments -were made in that direction by a number of distinguished physicians -and anatomists (Paracelsus, Servetus, Vesalius, and others). In 1628 -Harvey published his great discovery of the circulation of the blood, -and showed that the heart is a pump, which drives the red stream -unceasingly through the connected system of arteries and veins by a -rhythmic, unconscious contraction of its muscles. Not less important -were Harvey's researches into the procreation of animals, as a result -of which he formulated the well-known law: "Every living thing comes -from an egg" (_omne vivum ex ovo_). - -The powerful impetus which Harvey gave to physiological observation and -experiment led to a great number of discoveries in the sixteenth and -seventeenth centuries. These were co-ordinated for the first time by -the learned Albrecht Haller about the middle of the last century; in -his great work, _Elementa Physiologiae_, he established the inherent -importance of the science, independently of its relation to practical -medicine. In postulating, however, a special "sensitive force or -sensibility" for neural action, and a special "irritability" for -muscular movement, Haller gave strong support to the erroneous idea of -a specific "vital force" (_vis vitalis_). - -For more than a century afterwards, from the middle of the eighteenth -until the middle of the nineteenth century, medicine and (especially) -physiology were dominated by the old idea that a certain number of the -vital processes may be traced to physical and chemical causes, but that -others are the outcome of a special vital force which is independent -of physical agencies. However much scientists differed in their -conceptions of its nature and its relation to the "soul," they were all -agreed as to its independence of, and essential distinction from, the -chemico-physical forces of ordinary "matter"; it was a self-contained -force (_archaeus_), unknown in inorganic nature, which compelled -ordinary forces into its service. Not only the distinctly psychical -activity, the sensibility of the nerves and the irritability of the -muscles, but even the phenomena of sense activity, of reproduction, -and of development seemed so wonderful and so mysterious in their -sources that it was impossible to attribute them to simple physical -and chemical processes. As the free activity of the vital force -was purposive and conscious, it led, in philosophy, to a complete -_teleology_; especially did this seem indisputable when even the -"critical" philosopher Kant had acknowledged, in his famous critique -of the teleological position, that, though the mind's authority to -give a mechanical interpretation of all phenomena is theoretically -unlimited, yet its actual capacity for such interpretation does not -extend to the phenomena of organic life; here we are compelled to have -recourse to a _purposive_--therefore _supernatural_--principle. This -divergence of the _vital_ phenomena from the _mechanical_ processes of -life became, naturally, more conspicuous as science advanced in the -chemical and physical explanation of the latter. The circulation of the -blood and a number of other phenomena could be traced to mechanical -agencies; respiration and digestion were attributable to chemical -processes like those we find in inorganic nature. On the other hand, -it seemed impossible to do this with the wonderful performances of the -nerves and muscles, and with the characteristic life of the mind; the -co-ordination of all the different forces in the life of the individual -seemed also beyond such a mechanical interpretation. Hence there arose -a complete physiological dualism--an essential distinction was drawn -between inorganic and organic nature, between mechanical and vital -processes, between material force and life force, between the body and -the soul. At the beginning of the nineteenth century this vitalism was -firmly established in France by Louis Dumas, and in Germany by Reil. -Alexander Humboldt had already published a poetical presentation of it -in 1795, in his narrative of the _Legend of Rhodes_; it is repeated, -with critical notes, in his _Views of Nature_. - -In the first half of the seventeenth century the famous philosopher -Descartes, starting from Harvey's discovery of the circulation of the -blood, put forward the idea that the body of man, like that of other -animals, is merely an intricate machine, and that its movements take -place under the same mechanical laws as the movements of an automaton -of human construction. It is true that Descartes, at the same time, -claimed for man the exclusive possession of a perfectly independent, -immaterial soul, and held that its subjective experience, thought, -was the only thing in the world of which we have direct and certain -cognizance ("_Cogito, ergo sum_"). Yet this dualism did not prevent -him from doing much to advance our knowledge of the mechanical life -processes in detail. Borelli followed (1660) with a reduction of the -movements of the animal body to purely physical laws, and Sylvius -endeavored, about the same time, to give a purely chemical explanation -of the phenomena of digestion and respiration; the former founded the -_iatromechanical_, the latter the _iatrochemical_, school of medicine. -However, these rational tendencies towards a natural, mechanical -explanation of the phenomena of life did not attain to a universal -acceptance and application; in the course of the eighteenth century -they fell entirely away before the advance of teleological vitalism. -The final disproof of the latter and a return to mechanism only became -possible with the happy growth of the new science of comparative -physiology in the forties of the present century. - -Our knowledge of the vital functions, like our knowledge of the -structure of the human body, was originally obtained, for the most -part, not by direct observation of the human organism itself, but by -a study of the more closely related animals among the vertebrates, -especially the mammals. In this sense the very earliest beginning -of human anatomy and physiology was "comparative." But the distinct -science of "comparative physiology," which embraces the whole sphere -of life phenomena, from the lowest animal up to man, is a triumph of -the nineteenth century. Its famous creator was Johannes Müller, of -Berlin (born, the son of a shoemaker, at Coblentz, in 1801). For fully -twenty-five years--from 1833 to 1858--this most versatile and most -comprehensive biologist of our age evinced an activity at the Berlin -University, as professor and investigator, which is only comparable -with the associated work of Haller and Cuvier. Nearly every one of the -great biologists who have taught and worked in Germany for the last -sixty years was, directly or indirectly, a pupil of Johannes Müller. -Starting from the anatomy and physiology of man, he soon gathered all -the chief groups of the higher and lower animals within his sphere -of comparison. As, moreover, he compared the structure of extinct -animals with the living, and the healthy organism with the diseased, -endeavoring to bring together all the phenomena of life in a truly -philosophic fashion, he attained a biological knowledge far in advance -of his predecessors. - -The most valuable fruit of these comprehensive studies of Johannes -Müller was his _Manual of Human Physiology_. This classical work -contains much more than the title indicates; it is the sketch of -a comprehensive "comparative biology." It is still unsurpassed in -respect of its contents and range of investigation. In particular, -we find the methods of observation and experiment applied in it as -masterfully as the philosophic processes of induction and deduction. -Müller was originally a vitalist, like all the physiologists of his -time. Nevertheless, the current idea of a vital force took a novel -form in his speculations, and gradually transformed itself into the -very opposite. For he attempted to explain the phenomena of life -mechanically in every department of physiology. His "transfigured" -vital force was not _above_ the physical and chemical laws of the rest -of nature but entirely bound up with them. It was, in a word, nothing -more than life itself--that is, the sum of all the movements which we -perceive in the living organism. He sought especially to give them -the same mechanical interpretation in the life of the senses and of -the mind as in the working of the muscles; the same in the phenomena -of circulation, respiration, and digestion as in generation and -development. Müller's success was chiefly due to the fact that he -always began with the simplest life phenomena of the lowest animals, -and followed them step by step in their gradual development up to the -very highest, to man. In this his method of _critical comparison_ -proved its value both from the physiological and from the anatomical -point of view. Johannes Müller is, moreover, the only great scientist -who has equally cultivated these two branches of research, and combined -them with equal brilliancy. Immediately after his death his vast -scientific kingdom fell into four distinct provinces, which are now -nearly always represented by four or more chairs--human and comparative -anatomy, pathological anatomy, physiology, and the history of -evolution. This sudden division of Müller's immense realm of learning -in 1858 has been compared to the dissolution of the empire which -Alexander the Great had consolidated and ruled. - -Among the many pupils of Johannes Müller who, either during his -lifetime or after his death, labored hard for the advancement of the -various branches of biology, one of the most fortunate--if not the -most important--was Theodor Schwann. When the able botanist Schleiden, -in 1838, indicated the cell as the common elementary organ of all -plants, and proved that all the different tissues of the plant are -merely combinations of cells, Johannes Müller recognized at once the -extraordinary possibilities of this important discovery. He himself -sought to point out the same composition in various tissues of the -animal body--for instance, in the spinal cord of vertebrates--and -thus led his pupil, Schwann, to extend the discovery to all the -animal tissues. This difficult task was accomplished by Schwann in -his _Microscopic Researches into the Accordance in the Structure and -Growth of Plants and Animals_ (1839). Thus was the foundation laid -of the "cellular theory," the profound importance of which, both in -physiology and anatomy, has become clearer and more widely recognized -in each subsequent year. Moreover, it was shown by two other pupils -of Johannes Müller that the activity of all organisms is, in the -ultimate analysis, the activity of the components of their tissues, the -microscopic cells--these were the able physiologist Ernst Brücke, of -Vienna, and the distinguished histologist Albert Kölliker, of Würzburg. -Brücke correctly denominated the cells the "elementary organisms," and -showed that, in the body of man and of all other animals, they are the -only actual, independent factors of the life process. Kölliker earned -special distinction, not only in the construction of the whole science -of histology, but particularly by showing that the animal ovum and its -products are simple cells. - -Still, however widely the immense importance of the cellular theory for -all biological research was acknowledged, the "cellular physiology" -which is based on it only began an independent development very -recently. In this Max Verworn (of Jena) earned a twofold distinction. -In his _Psycho-physiological Studies of the Protistae_ (1889) he -showed, as a result of an ingenious series of experimental researches, -that the "theory of a cell-soul" which I put forward in 1866[11] -is completely established by an accurate study of the unicellular -protozoa, and that "the psychic phenomena of the protistæ form the -bridge which unites the chemical processes of inorganic nature with -the mental life of the highest animals." Verworn has further developed -these views, and based them on the modern theory of evolution, in -his _General Physiology_. This distinguished work returns to the -comprehensive point of view of Johannes Müller, in opposition to the -one-sided and narrow methods of those modern physiologists who think -to discover the nature of the vital phenomena by the exclusive aid of -chemical and physical experiments. Verworn showed that it is only by -Müller's comparative method and by a profound study of the physiology -of the cell that we can reach the higher stand-point which will give us -a comprehensive survey of the wonderful realm of the phenomena of life. -Only thus do we become convinced that the vital processes in man are -subject to the same physical and chemical laws as those of all other -animals. - -The fundamental importance of the cellular theory for all branches of -biology was made clear in the second half of the nineteenth century, -not only by the rapid progress of morphology and physiology, but also -by the entire reform of that biological science which has always -been deemed most important on account of its relation to practical -medicine--pathology, or the science of disease. Many even of the -older physicians were convinced that human diseases were natural -phenomena, like all other manifestations of life, and should be studied -scientifically, like other vital functions. Particular schools of -medicine--the Iatrophysical and the Iatrochemical--had already, in -the seventeenth century, attempted to trace the sources of disease to -certain physical and chemical changes. However, the imperfect condition -of science at that period precluded any lasting results of these -efforts. Many of the older theories, which sought the nature of disease -in supernatural and mystical causes, were almost universally accepted -down to the middle of the nineteenth century. - -It was then that Rudolf Virchow, another pupil of Müller, conceived -the happy idea of transferring the cellular theory from the healthy to -the diseased organism; he sought in the more minute metamorphoses of -the diseased cells and the tissues they composed the true source of -those larger changes which, in the form of disease, threaten the living -organism with peril and death. Especially during the seven years of -his professorship at Würzburg (1849-56) Virchow pursued his great task -with such brilliant results that his _Cellular Pathology_ (published in -1858) turned, at one stroke, the whole of pathology and the dependent -science of practical medicine into new and eminently fruitful paths. -This reform of medicine is significant for our present purpose in that -it led us to a monistic and purely scientific conception of disease. In -sickness, no less than in health, man is subject to the same eternal -"iron laws" of physics and chemistry as all the rest of the organic -world. - -Among the numerous classes of animals which modern zoology -distinguishes the mammals occupy a pre-eminent position, not only on -morphological grounds, but also for physiological reasons. As man -belongs to the class of mammals (see p. 27) by every portion of his -frame, we must expect him to share his characteristic functions with -the rest of the mammals. Such we find to be the case. The circulation -of the blood and respiration are accomplished in man under precisely -the same laws and in the same manner as in all the other mammals--_and -in these alone_; they are determined by the peculiar structure of -their heart and lungs. In mammals only is all the arterial blood -conducted from the left ventricle of the heart to the body by one, -the _left_, branch of the aorta, while in birds it passes along the -_right_ branch, and in reptiles along both branches. The blood of -mammals is distinguished from that of any other vertebrate by the -circumstance that its red cells have lost their nucleus (by reversion). -The respiratory movements are effected largely by the diaphragm in -this class of animals alone, because only in them does it form a -complete partition between the pectoral and abdominal cavities. Special -importance, however, in this highest class of animals, attaches to -the production of milk in the breasts (_mammae_), and to the peculiar -method of the rearing of the young, which entails the supplying of the -offspring with the mother's milk. As this nutritive process reacts most -powerfully on the other vital functions, and the maternal affection of -mammals must have arisen from this intimate form of rearing, the name -of the class justly reminds us of its great importance. In millions of -pictures, most of them produced by painters of the highest rank, the -"madonna with the child" is revered as the purest and noblest type of -maternal love--the instinct which is found in its extreme form in the -exaggerated tenderness of the mother-ape. - -As the apes approach nearest to man of all the mammals in point of -structure, we shall expect to hear the same of their vital functions; -and that we find to be the case. Everybody knows how closely the -habits, the movements, the sense activity, the mental life, and the -parental customs of apes resemble those of man. Scientific physiology -proves the same significant resemblance in other less familiar -processes, particularly in the working of the heart, the division -of the breasts, and the sexual life. In the latter connection it is -especially noteworthy that the mature females of many kinds of apes -suffer a periodical discharge of blood from the womb, which corresponds -to the menstruation of the human female. The secretion of the milk in -the glands and the suctorial process also take place in the female ape -in precisely the same fashion as in women. - -Finally, it is of especial interest that the speech of apes seems on -physiological comparison to be a stage in the formation of articulate -human speech. Among living apes there is an Indian species which is -musical; the _hylobates syndactylus_ sings a full octave in perfectly -pure, harmonious half-tones. No impartial philologist can hesitate any -longer to admit that our elaborate rational language has been slowly -and gradually developed out of the imperfect speech of our Pliocene -simian ancestors. - - - - -CHAPTER IV - -OUR EMBRYONIC DEVELOPMENT - - The Older Embryology--The Theory of Preformation--The Theory of - Scatulation: Haller and Leibnitz--The Theory of Epigenesis: C. F. - Wolff--The Theory of Germinal Layers: Carl Ernst Baer--Discovery - of the Human Ovum: Remak, Kölliker--The Egg-Cell and the - Sperm-Cell--The Theory of the Gastræa--Protozoa and Metazoa--The - Ova and the Spermatozoa: Oscar Hertwig--Conception--Embryonic - Development in Man--Uniformity of the Vertebrate Embryo--The - Germinal Membranes in Man--The Amnion, the Serolemma, and the - Allantois--The Formation of the Placenta and the "After-Birth"--The - _Decidua_ and the _Funiculus Umbilicalis_--The Discoid Placenta of - Man and the Ape - - -Comparative ontogeny, or the science of the development of the -individual animal, is a child of the nineteenth century in even a truer -sense than comparative anatomy and physiology. How is the child formed -in the mother's womb? How do animals evolve from ova? How does the -plant come forth from the seed? These pregnant questions have occupied -the thoughtful mind for thousands of years. Yet it is only seventy -years since the embryologist Baer pointed out the correct means and -methods for penetrating into the mysteries of embryonic life; it is -only forty years since Darwin, by his reform of the theory of descent, -gave us the key which should open the long-closed door, and lead to -a knowledge of embryonic agencies. As I have endeavored to give a -complete, popular presentation of this very interesting but difficult -study in the first section of my _Anthropogeny_, I will confine myself -here to a brief survey and discussion of the most important phenomena. -Let us first cast a historical glance at the older ontogeny, and the -theory of preformation which is connected with it. - -The classical works of Aristotle, the many-sided "father of science," -are the oldest known scientific sources of embryology, as we found them -to be for comparative anatomy. Not only in his great natural history, -but also in a special small work, _Five Books on the Generation and -Development of Animals_, the great philosopher gives us a host of -interesting facts, adding many observations on their significance; it -was not until our own days that many of them were fully appreciated, -and, indeed, we may say, discovered afresh. Naturally, many fables and -errors are mixed up with them; it was all that was known at that time -of the hidden growth of the human germ. Yet during the long space of -the next two thousand years the slumbering science made no further -progress. It was not until the commencement of the seventeenth century -that there was a renewal of activity. In 1600 the Italian anatomist -Fabricius ab Aquapendente published at Padua the first pictures and -descriptions of the embryos of man and some of the higher animals; in -1687 the famous Marcello Malpighi, of Bologna, a distinguished pioneer -alike in zoology and botany, published the first consistent exposition -of the growth of the chick in the hatched egg. - -All these older scientists were possessed with the idea that the -complete body, with all its parts, was already contained in the ovum -of animals, only it was so minute and transparent that it could not -be detected; that, therefore, the whole development was nothing more -than a _growth_, or an "unfolding," of the parts that were already -"infolded" (_involutae_). This erroneous notion, almost universally -accepted until the beginning of the present century, is called the -"preformation theory"; sometimes it is called the "evolution theory" -(in the literal sense of "unfolding"); but the latter title is accepted -by modern scientists for the very different theory of "transformation." - -Closely connected with the preformation theory, and as a logical -consequence of it, there arose in the last century a further theory -which keenly interested all thoughtful biologists--the curious -"theory of scatulation." As it was thought that the outline of the -entire organism, with all its parts, was present in the egg, the -ovary of the embryo had to be supposed to contain the ova of the -following generation; these, again, the ova of the next, and so on -_in infinitum_! On that basis the distinguished physiologist Haller -calculated that God had created together, 6000 years ago--on the sixth -day of his creatorial labors--the germs of 200,000,000,000 men, and -ingeniously packed them all in the ovary of our venerable mother Eve. -Even the gifted philosopher Leibnitz fully accepted this conclusion, -and embodied it in his monadist theory; and as, on his theory, soul and -body are in eternal, inseparable companionship, the consequence had to -be accepted for the soul; "the souls of men have existed in organized -bodies in their ancestors from Adam downward--that is, from the very -beginning of things." - -In the month of November, 1759, a young doctor of twenty-six years, -Caspar Friedrich Wolff (son of a Berlin tailor), published his -dissertation for the degree at Halle, under the title, _Theoria -Generationis_. Supported by a series of most laborious and painstaking -observations, he proved the entire falsity of the dominant theories of -preformation and scatulation. In the hatched egg there is at first no -trace of the coming chick and its organs; instead of it we find on top -of the yolk a small, circular, white disk. This thin "germinal disk" -becomes gradually round, and then breaks up into four folds, lying -upon each other, which are the rudiments of the four chief systems of -organs--the nervous system above, the muscular system underneath, the -vascular system (with the heart), and, finally, the alimentary canal. -Thus, as Wolff justly remarked, the embryonic development does not -consist in an unfolding of the preformed organs, but in a series of -new constructions; it is a true _epigenesis_. One part arises after -another, and all make their appearance in a simple form, which is very -different from the later structure. This only appears after a series of -most remarkable formations. Although this great discovery--one of the -most important of the eighteenth century--could be directly proved by a -verification of the facts Wolff had observed, and although the "theory -of generation" which was founded on it was in reality not a theory at -all, but a simple fact, it met with no sympathy whatever for half a -century. It was particularly retarded by the high authority of Haller, -who fought it strenuously with the dogmatic assertion that "there is -no such thing as development: no part of the animal body is formed -before another; all were created together." Wolff, who had to go to St. -Petersburg, was long in his grave before the forgotten facts he had -observed were discovered afresh by Oken at Jena, in 1806. - -After Wolff's "epigenesis theory" had been established by Oken and -Neckel (whose important work on the development of the alimentary -canal was translated from Latin into German), a number of young German -scientists devoted themselves eagerly to more accurate embryological -research. The most important and successful of these was Carl Ernst -Baer. His principal work appeared in 1828, with the title, _History of -the Development of Animals: Observations and Reflections_. Not only -the phenomena of the formation of the germ are clearly illustrated -and fully described in it, but it adds a number of very pregnant -speculations. In particular, the form of the embryo of man and the -mammals is correctly presented, and the vastly different development -of the lower invertebrate animals is also considered. The two leaflike -layers which appear in the round germ disk of the higher vertebrates -first divide, according to Baer, into two further layers, and these -four germinal layers are transformed into four tubes, which represent -the fundamental organs--the skin layer, the muscular layer, the -vascular layer, and the mucous layer. Then, by very complicated -evolutionary processes, the later organs arise, in substantially the -same manner, in man and all the other vertebrates. The three chief -groups of invertebrates, which in their turn differ widely from each -other, have a very different development. - -One of the most important of Baer's many discoveries was the finding of -the human ovum. Up to that time the little vesicles which are found in -great numbers in the human ovary and in that of all other mammals had -been taken for the ova. Baer was the first to prove, in 1827, that the -real ova are enclosed in these vesicles--the "Graafian follicles"--and -much smaller, being tiny spheres 1-120th inch in diameter, visible -to the naked eye as minute specks under favorable conditions. He -discovered likewise that from this tiny ovum of the mammal there -develops first a characteristic germ globule, a hollow sphere with -liquid contents, the wall of which forms the slender germinal membrane, -or blastoderm. - -Ten years after Baer had given a firm foundation to embryological -science by his theory of germ layers a new task confronted it on the -establishment of the cellular theory in 1838. What is the relation of -the ovum and the layers which arise from it to the tissues and cells -which compose the fully developed organism? The correct answer to this -difficult question was given about the middle of this century by two -distinguished pupils of Johannes Müller--Robert Remak, of Berlin, and -Albert Kölliker, of Würzburg. They showed that the ovum is at first one -simple cell, and that the many germinal globules, or granules, which -arise from it by repeated segmentation, are also simple cells. From -this mulberry-like group of cells are constructed first the germinal -layers, and subsequently by differentiation, or division of labor, -all the different organs. Kölliker has the further merit of showing -that the seminal fluid of male animals is also a mass of microscopic -cells. The active pin-shaped "seed-animalcules," or _spermatozoa_, in -it are merely ciliated cells, as I first proved in the case of the -seed-filaments of the sponge in 1866. Thus it was proved that both -the materials of generation, the male sperm and the female ova, fell -in with the cellular theory. That was a discovery of which the great -philosophic significance was not appreciated until a much later date, -on a close study of the phenomena of conception in 1875. - -All the older studies in embryonic development concern man and the -higher vertebrates, especially the embryonic bird, since hens' eggs -are the largest and most convenient objects for investigation, and -are plentiful enough to facilitate experiment; we can hatch them in -the incubator, as well as by the natural function of the hen, and -so observe from hour to hour, during the space of three weeks, the -whole series of formations, from the simple germ cell to the complete -organism. Even Baer had only been able to gather from such observations -the fact that the different classes of vertebrates agreed in the -characteristic form of the germ layers and the growth of particular -organs. In the innumerable classes of invertebrates, on the other -hand--that is, in the great majority of animals--the embryonic -development seemed to run quite a different course, and most of them -seemed to be altogether without true germinal layers. It was not until -about the middle of the century that such layers were found in some of -the invertebrates. Huxley, for instance, found them in the medusæ in -1849, and Kölliker in the cephalopods in 1844. Particularly important -was the discovery of Kowalewsky (1886) that the lowest vertebrate--the -lancelot, or amphioxus--is developed in just the same manner (and a -very original fashion it is) as an invertebrate, apparently quite -remote, tunicate, the sea-squirt, or ascidian. Even in some of the -worms, the radiata and the articulata, a similar formation of the -germinal layers was pointed out by the same observer. I myself was -then (since 1886) occupied with the embryology of the sponges, corals, -medusæ, and siphonophoræ, and, as I found the same formation of two -primary germ layers everywhere in these lowest classes of multicellular -animals, I came to the conclusion that this important embryonic -feature is common to the entire animal world. The circumstance that -in the sponges and the cnidaria (polyps, medusæ, etc.) the body -consists for a long time, sometimes throughout life, merely of two -simple layers of cells, seemed to me especially significant. Huxley -had already (1849) compared these, in the case of the medusæ, with the -two primary germinal layers of the vertebrates. On the ground of these -observations and comparisons I then, in 1872, in my _Philosophy of the -Calcispongiae_, published the "theory of the gastræa," of which the -following are the essential points: - -I. The whole animal world falls into two essentially different groups, -the unicellular primitive animals (Protozoa) and the multicellular -animals with complex tissues (Metazoa). The entire organism of the -protozoon (the rhizopods of the infusoria) remains throughout life a -single simple cell (or occasionally a loose colony of cells without -the formation of tissue, a _coenobium_). The organism of the metazoon, -on the contrary, is only unicellular at the commencement, and is -subsequently built up of a number of cells which form tissues. - -II. Hence the method of reproduction and development is very different -in each of these great categories of animals. The protozoa usually -multiply by _non-sexual_ means, by fission, gemmation, or spores; -they have no real ova and no sperm. The metazoa, on the contrary, are -divided into male and female sexes, and generally propagate sexually, -by means of true ova, which are fertilized by the male sperm. - -III. Hence, further, true germinal layers, and the tissues which are -formed from them, are found only in the metazoa; they are entirely -wanting in the protozoa. - -IV. In all the metazoa only two primary layers appear at first, and -these have always the same essential significance; from the _outer_ -layer the external skin and the nervous system are developed; from the -_inner_ layer are formed the alimentary canal and all the other organs. - -V. I called the germ, which always arises first from the impregnated -ovum, and which consists of these two primary layers, the "gut-larva," -or the _gastrula_; its cup-shaped body with the two layers encloses -originally a simple digestive cavity, the primitive gut (the -_progaster_ or _archenteron_), and its simple opening is the primitive -mouth (the _prostoma_ or _blastoporus_). These are the earliest organs -of the multicellular body, and the two cell layers of its enclosing -wall, simple epithelia, are its earliest tissues; all the other organs -and tissues are a later and secondary growth from these. - -VI. From this similarity, or _homology_, of the gastrula in all classes -of compound animals I drew the conclusion, in virtue of the biogenetic -law (p. 81), that all the metazoa come originally from one simple -ancestral form, the _gastraea_, and that this ancient (Laurentian), -long-extinct form had the structure and composition of the actual -gastrula, in which it is preserved by heredity. - -VII. This phylogenetic conclusion, based on the comparison of -ontogenetic facts, is confirmed by the circumstance that there are -several of these gastræades still in existence (_gastraemaria_, -_cyemaria_, _physemaria_, etc.), and also some ancient forms of -other animal groups whose organization is very little higher (the -_olynthus_ of the sponges, the _hydra_, or common fresh-water polyp, -of the cnidaria, the _convoluta_ and other cryptocæla, or worms of the -simplest type, of the _platodes_). - -VIII. In the further development of the various tissue-forming animals -from the gastrula we have to distinguish two principal groups. The -earlier and _lower_ types (the _coelenteria_ or _acoelomia_) have -no body cavity, no vent, and no blood; such is the case with the -gastræades, sponges, cnidaria, and platodes. The later and _higher_ -types (the _caelomaria_ or _bilateria_), on the other hand, have a -true body cavity, and generally blood and a vent; to these we must -refer the worms and the higher types of animals which were evolved from -these later on, the echinodermata, mollusca, articulata, tunicata, and -vertebrata. - -Those are the main points of my "gastræa theory"; I have since -enlarged the first sketch of it (given in 1872), and have endeavored -to substantiate it in a series of "Studies on the gastræa theory" -(1873-84). Although it was almost universally rejected at first, and -fiercely combated for ten years by many authorities, it is now (and has -been for the last fifteen years) accepted by nearly all my colleagues. -Let us now see what far-reaching consequences follow from it, and -from the evolution of the germ, especially with regard to our great -question, "the place of man in nature." - -The human ovum, like that of all other animals, is a single cell, and -this tiny globular egg cell (about the 120th of an inch in diameter) -has just the same characteristic appearance as that of all other -viviparous organisms. The little ball of protoplasm is surrounded -by a thick, transparent, finely reticulated membrane, called the -_zona pellucida_; even the little, globular, germinal vesicle (the -cell-nucleus), which is enclosed in the protoplasm (the cell-body), -is of the same size and the same qualities as in the rest of the -mammals. The same applies to the active spermatozoa of the male, -the minute, threadlike, ciliated cells of which millions are found -in every drop of the seminal fluid; on account of their lifelike -movements they were previously taken to be forms of life, as the name -indicates (spermatozoa--sperm animals). Moreover, the origin of both -these important sexual cells in their respective organs is the same in -man as in the other mammals; both the ova in the ovary of the female -and the spermatozoa in the spermarium of the male arise in the same -fashion--they always come from cells, which are originally derived from -the coelous epithelium, the layer of cells which clothes the cavity -of the body. - -The most important moment in the life of every man, as in that of all -other complex animals, is the moment in which he begins his individual -existence; it is the moment when the sexual cells of both parents meet -and coalesce for the formation of a single simple cell. This new cell, -the impregnated egg cell, is the individual stem cell (the _cytula_), -the continued segmentation of which produces the cells of the germinal -layers and the gastrula. With the formation of this cytula, hence in -the process of conception itself, the existence of the personality, the -independent individual, commences. This ontogenic fact is supremely -important, for the most far-reaching conclusions may be drawn from -it. In the first place, we have a clear perception that man, like all -the other complex animals, inherits all his personal characteristics, -bodily and mental, from his parents; and, further, we come to the -momentous conclusion that the new personality which arises thus can lay -no claim to "immortality." - -Hence the minute processes of conception and sexual generation are -of the first importance. We are, however, only familiar with their -details since 1875, when Oscar Hertwig, my pupil and fellow-traveller -at that time, began his researches into the impregnation of the egg -of the sea-urchin at Ajaccio, in Corsica. The beautiful capital of -the island in which Napoleon the Great was born, in 1769, was also -the spot in which the mysteries of animal conception were carefully -studied for the first time in their most important aspects. Hertwig -found that the one essential element in conception is the coalescence -of the two sexual cells and their nuclei. Only one out of the millions -of male ciliated cells which press round the ovum penetrates to its -nucleus. The nuclei of both cells, of the spermatozoon and of the ovum, -drawn together by a mysterious force, which we take to be a chemical -sense-activity, related to smell, approach each other and melt into -one. Thus, by the sensitive perception of the sexual nuclei, following -upon a kind of "erotic chemicotropism," a new cell is formed, which -unites in itself the inherited qualities of both parents; the nucleus -of the spermatozoon conveys the paternal features, the nucleus of the -ovum those of the mother, to the stem cell, from which the child is -to be developed. That applies both to the bodily and to the mental -characteristics. - -The formation of the germinal layers by the repeated division of -the stem cell, the growth of the gastrula and of the later germ -structures which succeed it, take place in man in just the same manner -as in the other higher mammals, under the peculiar conditions which -differentiate this group from the lower vertebrates. In the earlier -stages of development these special characters of the placentalia are -not to be detected. The significant embryonic or larval form of the -chordula, which succeeds the gastrula, has substantially the same -structure in all vertebrates; a simple straight rod, the dorsal cord, -lies lengthways along the main axis of the shield-shaped body--the -"embryonic shield"; above the cord the spinal marrow develops out -of the outer germinal layer, while the gut makes its appearance -underneath. Then, on both sides, to the right and left of the axial -rod, appear the segments of the "pro-vertebræ" and the outlines of -the muscular plates, with which the formation of the members of the -vertebrate body begins. The gill-clefts appear on either side of the -fore-gut; they are the openings of the gullet, through which, in our -primitive fish-ancestors, the water which had entered at the mouth -for breathing purposes made its exit at the sides of the head. By a -tenacious heredity these gill-clefts, which have no meaning except for -our fish-like aquatic ancestors, are still preserved in the embryo of -man and all the other vertebrates. They disappear after a time. Even -after the five vesicles of the embryonic brain appear in the head, -and the rudiments of the eyes and ears at the sides, and after the -legs sprout out at the base of the fish-like embryo, in the form of -two roundish, flat buds, the foetus is still so like that of other -vertebrates that it is indistinguishable from them. - -The substantial similarity in outer form and inner structure which -characterizes the embryo of man and other vertebrates in this early -stage of development is an embryological fact of the first importance; -from it, by the fundamental law of biogeny, we may draw the most -momentous conclusions. There is but one explanation of it--heredity -from a common parent form. When we see that, at a certain stage, -the embryos of man and the ape, the dog and the rabbit, the pig and -the sheep, although recognizable as higher vertebrates, cannot be -distinguished from each other, the fact can only be elucidated by -assuming a common parentage. And this explanation is strengthened when -we follow the subsequent divergence of these embryonic forms. The -nearer two animals are in their bodily structure, and, therefore, in -the scheme of nature, so much the longer do we find their embryos to -retain this resemblance, and so much the closer do they approach each -other in the ancestral tree of their respective group, so much the -closer is their genetic relationship. Hence it is that the embryos of -man and the anthropoid ape retain the resemblance much later, at an -advanced stage of development, when their distinction from the embryos -of other mammals can be seen at a glance. I have illustrated this -significant fact by a juxtaposition of corresponding stages in the -development of a number of different vertebrates in my _Natural History -of Creation_ and in my _Anthropogeny_. - -The great phylogenetic significance of the resemblance we have -described is seen, not only in the comparison of the embryos of -vertebrates, but also in the comparison of their protective membranes. -All vertebrates of the three higher classes--reptiles, birds, and -mammals--are distinguished from the lower classes by the possession -of certain special foetal membranes, the amnion and the serolemma. -The embryo is enclosed in these membranes, or bags, which are full of -water, and is thus protected from pressure or shock. This provident -arrangement probably arose during the Permian period, when the oldest -reptiles, the _proreptilia_, the common ancestors of all the amniotes -(animals with an _amnion_), completely adapted themselves to a life on -land. Their direct ancestors, the amphibia, and the fishes are devoid -of these foetal membranes; they would have been superfluous to these -inhabitants of the water. With the inheritance of these protective -coverings are closely connected two other changes in the amniotes: -firstly, the entire disappearance of the gills (while the gill arches -and clefts continue to be inherited as "rudimentary organs"); secondly, -the construction of the _allantois_. This vesicular bag, filled with -water, grows out of the hind-gut in the embryo of all the amniotes, -and is nothing else than an enlargement of the bladder of their -amphibious ancestors. From its innermost and inferior section is formed -subsequently the permanent bladder of the amniotes, while the larger -outer part shrivels up. Usually this has an important part to play for -a long time as the respiratory organ of the embryo, a number of large -blood-vessels spreading out over its inner surface. The formation of -the membranes, the amnion and the serolemma, and of the allantois, -is just the same, and is effected by the same complicated process of -growth, in man as in all the other amniotes; _man is a true amniote_. - -The nourishment of the foetus in the maternal womb is effected, as -is well known, by a peculiar organ, richly supplied with blood at its -surface, called the _placenta_. This important nutritive organ is a -spongy, round disk, from six to eight inches in diameter, about an -inch thick, and one or two pounds in weight; it is separated after -the birth of the child, and issues as the "after-birth." The placenta -consists of two very different parts, the foetal and the maternal -part. The latter contains highly developed sinuses, which retain the -blood conveyed to them by the arteries of the mother. On the other -hand, the foetal placenta is formed by innumerable branching tufts or -villi, which grow out of the outer surface of the allantois, and derive -their blood from the umbilical vessels. The hollow, blood-filled villi -of the foetal placenta protrude into the sinuses of the maternal -placenta, and the slender membrane between the two is so attenuated -that it offers no impediment to the direct interchange of material -through the nutritive blood-stream (by osmosis). - -In the older and lower groups of the placentals the entire surface -of the chorion is covered with a number of short villi; these -"chorion-villi" take the form of pit-like depressions of the mucous -membrane of the mother, and are easily detached at birth. That -happens in most of the ungulata (the sow, camel, mare, etc.), the -cetacea, and the prosimiæ; these "mallo-placentalia" (with a _diffuse_ -placenta) have been denominated the _indeciduata_. The same formation -is present in man and the other placentals in the beginning. It is -soon modified, however, as the villi on one part of the chorion are -withdrawn; while on the other part they grow proportionately stronger, -and unite intimately with the mucous membrane of the womb. It is in -consequence of this intimate blending that a portion of the uterus is -detached at birth, and carried away with loss of blood. This detachable -membrane--the _decidua_--is a characteristic of the higher placentalia, -which have, consequently, been grouped under the title of _deciduata_; -to that category belong the carnassia, rodentia, simiæ, and man. In -the carnassia and some of the ungulata (the elephant, for instance) -the placenta takes the form of a girdle, hence they are known as the -_zonoplacentalia_; in the rodentia, the insectivora (the mole and the -hedge-hog), the apes, and man, it takes the form of a disk. - -Even ten years ago the majority of embryologists thought that man -was distinguished by certain peculiarities in the form of the -placenta--namely, by the possession of what is called the _decidua -reflexa_, and by a special formation of the umbilical chord which -unites the _decidua_ to the foetus. It was supposed that the rest -of the placentals, including the apes, were without these special -embryonic structures. The _funiculus umbilicalis_ is a smooth, -cylindrical cord, from sixteen to twenty-three inches long, and as -thick as the little finger. It forms the connecting link between the -foetus and the maternal placenta, since it conducts the nutritive -vessels from the body of the foetus to the placenta; it comprises, -besides, the pedicle of the allantois and the yelk-sac. The yelk-sac in -the human case forms the greater portion of the germinal vesicle during -the third week of gestation; but it shrivels up afterwards so that it -was formerly entirely missed in the mature foetus. Yet it remains all -the time in a rudimentary condition, and may be detected even after -birth as the little umbilical vesicle. Moreover, even the vesicular -structure of the allantois disappears at an early stage in the human -case; with a deflection of the amnion, it gives rise to the pedicle. -We cannot enter here into a discussion of the complicated anatomical -and embryological relations of these structures. I have described and -illustrated them in my _Anthropogeny_ (twenty-third chapter). - -The opponents of evolution still appealed to these "special features" -of human embryology, which were supposed to distinguish man from all -the other mammals, even so late as ten years ago. But in 1890 Emil -Selenka proved that the same features are found in the anthropoid apes, -especially in the orang (_satyrus_), while the lower apes are without -them. Thus Huxley's pithecometra thesis was substantiated once more: -"The differences between man and the great apes are not so great as -are those between the manlike apes and the lower monkeys." The supposed -"evidences _against_ the near blood-relationship of man and the apes" -proved, on a closer examination of the real circumstances, to be strong -reasons in favor of it. - -Every scientist who penetrates with open eyes into this dark but -profoundly interesting labyrinth of our embryonic development, and who -is competent to compare it critically with that of the rest of the -mammals, will find in it a most important aid towards the elucidation -of the descent of our species. For the various stages of our embryonic -development, in the character of _palingenetic_ phenomena of heredity, -cast a brilliant light on the corresponding stages of our ancestral -tree, in accordance with the great law of biogeny. But even the -_cenogenetic_ phenomena of adaptation, the formation of the temporary -foetal organs--the characteristic foetal membranes, and especially -the placenta--gives us sufficiently definite indications of our _close -genetic relationship with the primates_. - - - - -CHAPTER V - -THE HISTORY OF OUR SPECIES - - Origin of Man--Mythical History of Creation--Moses and Linné--The - Creation of Permanent Species--The Catastrophic Theory: - Cuvier--Transformism: Goethe--Theory of Descent: Lamarck--Theory - of Selection: Darwin--Evolution (Phylogeny)--Ancestral - Trees--General Morphology--Natural History of Creation--Systematic - Phylogeny--Fundamental Law of Biogeny--Anthropogeny--Descent of Man - from the Ape--Pithecoid Theory--The Fossil Pithecanthropus of Dubois - - -The youngest of the great branches of the living tree of biology is -the science we call biological evolution, or _phylogeny_. It came into -existence much later, and under much more difficult circumstances, than -its natural sister, embryonic evolution or _ontogeny_. The object of -the latter was to attain a knowledge of the mysterious processes by -which the individual organism, plant or animal, developed from the egg. -Phylogeny has to answer the much more obscure and difficult question: -"What is the origin of the different organic species of plants and -animals?" - -Ontogeny (embryology and metamorphism) could follow the empirical -method of direct observation in the solution of its not remote problem; -it needed but to follow, day by day and hour by hour, the visible -changes which the foetus experiences during a brief period in the -course of its development from the ovum. Much more difficult was -the remote problem of phylogeny; for the slow processes of gradual -construction, which effect the rise of new species of animals and -plants, go on imperceptibly during thousands and even millions of -years. Their direct observation is possible only within very narrow -limits; the vast majority of these historical processes can only be -known by direct inference--by critical reflection, and by a comparative -use of empirical sciences which belong to very different fields of -thought, palæontology, ontogeny, and morphology. To this we must -add the immense opposition which was everywhere made to biological -evolution on account of the close connection between questions of -organic creation and supernatural myths and religious dogmas. For these -reasons it can easily be understood how it is that the scientific -existence of a true theory of origins was only secured, amid fierce -controversy, in the course of the last forty years. - -Every serious attempt that was made before the beginning of the -nineteenth century to solve the problem of the origin of species -lost its way in the mythological labyrinth of the supernatural -stories of creation. The efforts of a few distinguished thinkers to -emancipate themselves from this tyranny and attain to a naturalistic -interpretation proved unavailing. A great variety of creation myths -arose in connection with their religion in all the ancient civilized -nations. During the Middle Ages triumphant Christendom naturally -arrogated to itself the sole right of pronouncing on the question; and, -the Bible being the basis of the structure of the Christian religion, -the whole story of creation was taken from the book of Genesis. Even -Carl Linné, the famous Swedish scientist, started from that basis -when, in 1735, in his classical _Systema Naturae_, he made the first -attempt at a systematic arrangement, nomenclature, and classification -of the innumerable objects in nature. As the best practical aid in that -attempt he introduced the well-known double or binary nomenclature; to -each kind of animals and plants he gave a particular specific name, -and added to it the wider-reaching name of the genus. A _genus_ served -to unite the nearest related _species_; thus, for instance, Linné -grouped under the genus "dog" (_canis_), as different species, the -house-dog (_canis familiaris_), the jackal (_canis aureus_), the wolf -(_canis lupus_) the fox (_canis vulpes_), etc. This binary nomenclature -immediately proved of such great practical assistance that it was -universally accepted, and is still always followed in zoological and -botanical classification. - -But the theoretical dogma which Linné himself connected with his -practical idea of species was fraught with the gravest peril to -science. The first question which forced itself on the mind of the -thoughtful scientist was the question as to the nature of the concept -of species, its contents, and its range. And the creator of the idea -answered this fundamental question by a naïve appeal to the dominant -Mosaic legend of creation: "_Species tot sunt diversae, quot diversas -formas ab initio creavit infinitum ens_"--(There are just so many -distinct species as there were distinct types created in the beginning -by the Infinite). This theosophic dogma cut short all attempt at a -natural explanation of the origin of species. Linné was acquainted only -with the plant and animal worlds that exist to-day; he had no suspicion -of the much more numerous extinct species which had peopled the earth -with their varying forms in the earlier period of its development. - -It was not until the beginning of the nineteenth century that we were -introduced to these fossil animals by Cuvier. In his famous work on -the fossil bones of the four-footed vertebrates he gave (1812) the -first correct description and true interpretation of many of these -fossil remains. He showed, too, that a series of very different animal -populations have succeeded each other in the various stages of the -earth's history. Since Cuvier held firmly to Linné's idea of the -absolute permanency of species, he thought their origin could only be -explained by the supposition that a series of great cataclysms and new -creations had marked the history of the globe; he imagined that all -living creatures were destroyed at the commencement of each of these -terrestrial revolutions, and an entirely new population was created -at its close. Although this "catastrophic theory" of Cuvier's led to -the most absurd consequences, and was nothing more than a bald faith -in miracles, it obtained almost universal recognition, and reigned -triumphant until the coming of Darwin. - -It is easy to understand that these prevalent ideas of the absolute -unchangeability and supernatural creation of organic species could not -satisfy the more penetrating thinkers. We find several eminent minds -already, in the second half of the last century, busy with the attempt -to find a natural explanation of the "problem of creation." Pre-eminent -among them was the great German poet and philosopher, Wolfgang Goethe, -who, by his long and assiduous study of morphology, obtained, more than -a hundred years ago, a clear insight into the intimate connection of -all organic forms, and a firm conviction of a common natural origin. -In his famed _Metamorphosis of Plants_ (1790) he derived all the -different species of plants from one primitive type, and all their -different organs from one primitive organ--the leaf. In his vertebral -theory of the skull he endeavored to prove that the skulls of the -vertebrates--including man--were all alike made up of certain groups -of bones, arranged in a definite structure, and that these bones are -nothing else than transformed vertebræ. It was his penetrating study -of comparative osteology that led Goethe to a firm conviction of the -unity of the animal organization; he had recognized that the human -skeleton is framed on the same fundamental type as that of all other -vertebrates--"built on a primitive plan that only deviates more or less -to one side or other in its very constant features, and still develops -and refashions itself daily." This remodelling, or transformation, -is brought about, according to Goethe, by the constant interaction -of two powerful constructive forces--a centripetal force within the -organism, the "tendency to specification," and a centrifugal force -without, the tendency to variation, or the "idea of metamorphosis"; -the former corresponds to what we now call heredity, the latter to -the modern idea of adaptation. How deeply Goethe had penetrated into -their character by these philosophic studies of the "construction and -reconstruction of organic natures," and how far, therefore, he must be -considered the most important precursor of Darwin and Lamarck,[12] may -be gathered from the interesting passages from his works which I have -collected in the fourth chapter of my _Natural History of Creation_. -These evolutionary ideas of Goethe, however, like analogous ideas of -Kant, Owen, Treviranus, and other philosophers of the commencement of -the century (which we have quoted in the above work), did not amount to -more than certain general conclusions. They had not that great lever -which the "natural history of creation" needed for its firm foundation -on a criticism of the dogma of fixed species; this lever was first -supplied by Lamarck. - -The first thorough attempt at a scientific establishment of transformism -was made at the beginning of the nineteenth century by the great -French scientist Jean Lamarck, the chief opponent of his colleague, -Cuvier, at Paris. He had already, in 1802, in his _Observations on -Living Organisms_, expressed the new ideas as to the mutability and -formation of species, which he thoroughly established in 1809 in the -two volumes of his profound work, _Philosophie Zoologique_. In this -work he first gave expression to the correct idea, in opposition to -the prevalent dogma of fixed species, that the organic "species" is -an _artificial abstraction_, a concept of only relative value, like -the wider-ranging concepts of genus, family, order, and class. He -went on to affirm that all species are changeable, and have arisen -from older species in the course of very long periods of time. The -common parent forms from which they have descended were originally -very simple and lowly organisms. The first and oldest of them arose -by abiogenesis. While the type is preserved by _heredity_ in the -succession of generations, _adaptation_, on the other hand, effects -a constant modification of the species by change of habits and the -exercise of the various organs. Even our human organism has arisen in -the same natural manner, by gradual transformation, from a group of -pithecoid mammals. For all these phenomena--indeed, for all phenomena -both in nature and in the mind--Lamarck takes exclusively mechanical, -physical, and chemical activities to be the true efficient causes. His -magnificent _Philosophie Zoologique_ contains all the elements of a -purely monistic system of nature on the basis of evolution. I have -fully treated these achievements of Lamarck in the fourth chapter of my -_Anthropogeny_, and in the fourth chapter of the _Natural History of -Creation_. - -Science had now to wait until this great effort to give a scientific -foundation to the theory of evolution should shatter the dominant myth -of a "specific creation, and open out the path of natural" development. -In this respect Lamarck was not more successful in resisting the -conservative authority of his great opponent, Cuvier, than was his -colleague and sympathizer, Geoffrey St. Hilaire, twenty years later. -The famous controversies which he had with Cuvier in the Parisian -Academy in 1830 ended with the complete triumph of the latter. I have -elsewhere fully described these conflicts, in which Goethe took so -lively an interest. The great expansion which the study of biology -experienced at that time, the abundance of interesting discoveries -in comparative anatomy and physiology, the establishment of the -cellular theory, and the progress of ontogeny, gave zoologists and -botanists so overwhelming a flood of welcome material to deal with -that the difficult and obscure question of the origin of species was -easily forgotten for a time. People rested content with the old dogma -of creation. Even when Charles Lyell refuted Cuvier's extraordinary -"catastrophic theory" in his _Principles of Geology_, in 1830, and -vindicated a natural, continuous evolution for the inorganic structure -of our planet, his simple principle of continuity found no one to -apply it to the inorganic world. The rudiments of a natural phylogeny -which were buried in Lamarck's works were as completely forgotten as -the germ of a natural ontogeny which Caspar Friedrich Wolff had given -fifty years earlier in his _Theory of Generation_. In both cases a full -half-century elapsed before the great idea of a natural development -won a fitting recognition. Only when Darwin (in 1859) approached the -solution of the problem from a different side altogether, and made -a happy use of the rich treasures of empirical knowledge which had -accumulated in the mean time, did men begin to think once more of -Lamarck as his great precursor. - -The unparalleled success of Charles Darwin is well known. It shows him -to-day, at the close of the century, to have been, if not the greatest, -at least the most effective of its distinguished scientists. No other -of the many great thinkers of our time has achieved so magnificent, so -thorough, and so far-reaching a success with a single classical work as -Darwin did in 1859 with his famous _Origin of Species_. It is true that -the reform of comparative anatomy and physiology by Johannes Müller -had inaugurated a new and fertile epoch for the whole of biology, that -the establishment of the cellular theory by Schleiden and Schwann, the -reform of ontogeny by Baer, and the formulation of the law of substance -by Robert Mayer and Helmholtz were scientific facts of the first -importance; but no one of them has had so profound an influence on the -whole structure of human knowledge as Darwin's theory of the natural -origin of species. For it at once gave us the solution of the mystic -"problem of creation," the great "question of all questions"--the -problem of the true character and origin of man himself. - -If we compare the two great founders of transformism, we find in -Lamarck a preponderant inclination to _deduction_, and to forming a -completely monistic scheme of nature; in Darwin we have a predominant -application of _induction_, and a prudent concern to establish the -different parts of the theory of selection as firmly as possible on a -basis of observation and experiment. While the French scientist far -outran the then limits of empirical knowledge, and rather sketched the -programme of future investigation, the English empiricist was mainly -preoccupied about securing a unifying principle of interpretation for -a mass of empirical knowledge which had hitherto accumulated without -being understood. We can thus understand how it was that the success -of Darwin was just as overwhelming as that of Lamarck was evanescent. -Darwin, however, had not only the signal merit of bringing all the -results of the various biological sciences to a common focus in the -principle of descent, and thus giving them a harmonious interpretation, -but he also discovered, in the principle of selection, that direct -cause of transformation which Lamarck had missed. In applying, as a -practical breeder, the experience of artificial selection to organisms -in a state of nature, and in recognizing in the "struggle for life" the -selective principle of natural selection, Darwin created his momentous -"theory of selection," which is what we properly call Darwinism. - -One of the most pressing of the many important tasks which Darwin -proposed to modern biology was the reform of the zoological and -botanical system. Since the innumerable species of animals and plants -were not created by a supernatural miracle, but evolved by natural -processes, their ancestral tree is their "natural system." The first -attempt to frame a system in this sense was made by myself in 1866, -in my _General Morphology of Organisms_. The first volume of this -work ("General Anatomy") dealt with the "mechanical science of the -developed forms"; the second volume ("General Evolution") was occupied -with the science of the "developing forms." The systematic introduction -to the latter formed a "genealogical survey of the natural system -of organisms." Until that time the term "evolution" had been taken -to mean exclusively, both in zoology and botany, the development of -individual organisms--embryology, or metamorphic science. I established -the opposite view, that this history of the embryo (ontogeny) must be -completed by a second, equally valuable, and closely connected branch -of thought--the history of the race (phylogeny). Both these branches -of evolutionary science are, in my opinion, in the closest causal -connection; this arises from the reciprocal action of the laws of -heredity and adaptation; it has a precise and comprehensive expression -in my "fundamental law of biogeny." - -As the new views I had put forward in my _General Morphology_ met with -very little notice, and still less acceptance, from my scientific -colleagues, in spite of their severely scientific setting, I thought -I would make the most important of them accessible to a wider circle -of informed readers by a smaller work, written in a more popular -style. This was done in 1868, in _The Natural History of Creation_ (a -series of popular scientific lectures on evolution in general, and the -systems of Darwin, Goethe, and Lamarck in particular). If the success -of my _General Morphology_ was far below my reasonable anticipation, -that of _The Natural History of Creation_ went far beyond it. In a -period of thirty years nine editions and twelve different translations -of it have appeared. In spite of its great defects, the book has -contributed much to the popularization of the main ideas of modern -evolution. Still, I could only give the barest outlines in it of my -chief object, the phylogenetic construction of a natural system. I -have, therefore, given the complete proof, which is wanting in the -earlier work, of the phylogenetic system in a subsequent larger work, -my _Systematic Phylogeny_ (outlines of a natural system of organisms -on the basis of their specific development). The first volume of -it deals with the protists and plants (1894), the second with the -invertebrate animals (1896), the third with the vertebrates (1895). The -ancestral tree of both the smaller and the larger groups is carried -on in this work as far as my knowledge of the three great "ancestral -documents"--palæontology, ontogeny, and morphology--qualified me to -extend it. - -I had already, in my _General Morphology_ (at the end of the fifth -book), described the close causative connection which exists, in -my opinion, between the two branches of organic evolution as one -of the most important ideas of transformism, and I had framed a -precise formula for it in a number of "theses on the causal nexus of -biontic and phyletic development": "_Ontogenesis is a brief and rapid -recapitulation of phylogenesis_, determined by the physiological -functions of heredity (generation) and adaptation (maintenance)." -Darwin himself had emphasized the great significance of his theory -for the elucidation of embryology in 1859, and Fritz Müller had -endeavored to prove it as regards the Crustacea in the able little -work, _Facts and Arguments for Darwin_ (1864). My own task has been -to prove the universal application and the fundamental importance of -the biogenetic law in a series of works, especially in the _Biology -of the Calcispongiae_ (1872), and in _Studies on the Gastraea Theory_ -(1873-1884). The theory of the homology of the germinal layers and of -the relations of _palingenesis_ to _cenogenesis_ which I have exposed -in them has been confirmed subsequently by a number of works of other -zoologists. That theory makes it possible to follow nature's law of -unity in the innumerable variations of animal embryology; it gives us -for their ancestral history a common derivation from a simple primitive -stem form. - -The far-seeing founder of the theory of descent, Lamarck, clearly -recognized in 1809 that it was of universal application; that even man -himself, the most highly developed of the mammals, is derived from the -same stem as all the other mammals; and that this in its turn belongs -to the same older branch of the ancestral tree as the rest of the -vertebrates. He had even indicated the agencies by which it might be -possible to explain man's descent from the apes as the nearest related -mammals. Darwin, who was, naturally, of the same conviction, purposely -avoided this least acceptable consequence of his theory in his chief -work in 1859, and put it forward for the first time in his _Descent of -Man_ in 1871. In the mean time (1863) Huxley had very ably discussed -this most important consequence of evolution in his famous _Place of -Man in Nature_. With the aid of comparative anatomy and ontogeny, -and the support of the facts of palæontology, Huxley proved that the -"descent of man from the ape" is a necessary consequence of Darwinism, -and that no other scientific explanation of the origin of the human -race is possible. Of the same opinion was Karl Gegenbaur, the most -distinguished representative of comparative anatomy, who lifted his -science to a higher level by a consistent and ingenious application of -the theory of descent. - -As a further consequence of the "pithecoid theory" (the theory of the -descent of man from the ape) there now arose the difficult task of -investigating, not only the nearest related mammal ancestors of man -in the Tertiary epoch, but also the long series of the older animal -ancestors which had lived in earlier periods of the earth's history and -been developed in the course of countless millions of years. I had made -a start with the hypothetical solution of this great historic problem -in my _General Morphology_; a further development of it appeared in -1874 in my _Anthropogeny_ (first section, Origin of the Individual; -second section, Origin of the Race). The fourth, enlarged, edition of -this work (1891) contains that theory of the development of man which -approaches nearest, in my own opinion, to the still remote truth, in -the light of our present knowledge of the documentary evidence. I was -especially preoccupied in its composition to use the three empirical -"documents"--palæontology, ontogeny, and morphology (or comparative -anatomy)--as evenly and harmoniously as possible. It is true that my -hypotheses were in many cases supplemented and corrected in detail by -later phylogenetic research; yet I am convinced that the ancestral tree -of human origin which I have sketched therein is substantially correct. -For the historical succession of vertebrate fossils corresponds -completely with the morphological evolutionary scale which is revealed -to us by comparative anatomy and ontogeny. After the Silurian fishes -come the _dipnoi_ of the Devonian period--the Carboniferous amphibia, -the Permian reptilia, and the Mesozoic mammals. Of these, again, the -lowest forms, the monotremes, appear first in the Triassic period, -the marsupials in the Jurassic, and then the oldest placentals in -the Cretaceous. Of the placentals, in turn, the first to appear in -the oldest Tertiary period (the Eocene) are the lowest primates, -the prosimiæ, which are followed by the simiæ in the Miocene. Of the -catarrhinæ, the cynopitheci precede the anthropomorpha; from one branch -of the latter, during the Pliocene period, arises the ape-man without -speech (the _pithecanthropus alalus_); and from him descends, finally, -speaking man. - -The chain of our earlier invertebrate ancestors is much more difficult -to investigate and much less safe than this tree of our vertebrate -predecessors; we have no fossilized relics of their soft, boneless -structures, so palæontology can give us no assistance in this case. -The evidence of comparative anatomy and ontogeny, therefore, becomes -all the more important. Since the human embryo passes through the -same _chordula_-stage as the germs of all other vertebrates, since -it evolves, similarly, out of two germinal layers of a _gastrula_, -we infer, in virtue of the biogenetic law, the early existence of -corresponding ancestral forms--vermalia, gastræada, etc. Most important -of all is the fact that the human embryo, like that of all other -animals, arises originally from a single cell; for this "stem-cell" -(_cytula_)--the impregnated egg cell--points indubitably to a -corresponding unicellular ancestor, a primitive, Laurentian protozoon. - -For the purpose of our monistic philosophy, however, it is a matter of -comparative indifference how the succession of our animal predecessors -may be confirmed in detail. Sufficient for us, as an incontestable -historical fact, is the important thesis that man descends immediately -from the ape, and secondarily from a long series of lower vertebrates. -I have laid stress on the logical proof of this "pithecometra-thesis" -in the seventh book of the _General Morphology_: "The thesis that -man has been evolved from lower vertebrates, and immediately from the -_simiae_, is a special inference which results with absolute necessity -from the general inductive law of the theory of descent." - -For the definitive proof and establishment of this fundamental -pithecometra-thesis the palæontological discoveries of the last -thirty years are of the greatest importance; in particular, the -astonishing discoveries of a number of extinct mammals of the Tertiary -period have enabled us to draw up clearly in its main outlines the -evolutionary history of this most important class of animals, from -the lowest oviparous monotremes up to man. The four chief groups -of the placentals, the heterogeneous legions of the carnassia, the -rodentia, the ungulata, and the primates, seem to be separated by -profound gulfs, when we confine our attention to their representatives -of to-day. But these gulfs are completely bridged, and the sharp -distinctions of the four legions are entirely lost, when we compare -their extinct predecessors of the Tertiary period, and when we go -back into the Eocene twilight of history, in the oldest part of the -Tertiary period--at least three million years ago. There we find the -great sub-class of the placentals, which to-day comprises more than -two thousand five hundred species, represented by only a small number -of little, insignificant "proplacentals"; and in these _prochoriata_ -the characters of the four divergent legions are so intermingled and -toned down that we cannot in reason do other than consider them as the -precursors of those features. The oldest carnassia (the _ictopsales_), -the oldest rodentia (the _esthonychales_), the oldest ungulata (the -_condylarthrales_) and the oldest primates (the _lemuravales_), all -have the same fundamental skeletal structure, and the same typical -dentition of the primitive placentals, consisting of forty-four teeth -(three incisors, one canine, four premolars, and three molars in each -half of the jaw); all are characterized by the small size and the -imperfect structure of the brain (especially of its chief part, the -cortex, which does not become a true "organ of thought" until later on -in the Miocene and Pliocene representatives); they have all short legs -and five-toed, flat-soled feet (_plantigrada_). In many cases among -these oldest placentals of the Eocene period it was very difficult -to say at first whether they should be classed with the carnassia, -rodentia, ungulata, or primates; so very closely, even to confusion, -do these four groups of the placentals, which diverge so widely -afterwards, approach each other at that time. Their common origin from -a single ancestral group follows incontestably. These _prochoriata_ -lived in the preceding Cretaceous period (more than three million years -ago), and were probably developed in the Jurassic period from a group -of insectivorous marsupials (_amphitheria_) by the formation of a -primitive _placenta diffusa_, a placenta of the simplest type. - -But the most important of all the recent palaeontological discoveries -which have served to elucidate the origin of the placentals relate -to our own stem, the legion of primates. Formerly fossil remains of -the primates were very scarce. Even Cuvier, the great founder of -palaeontology, maintained until his last day (1832) that there were no -fossilized primates; he had himself, it is true, described the skull -of an Eocene prosimiæ (_adapis_), but he had wrongly classed it with -the ungulata. However, during the last twenty years a fair number of -well-preserved fossilized skeletons of prosimiæ and simiæ have been -discovered; in them we find all the chief intermediate members which -complete the connecting chain of ancestors from the oldest prosimiæ to -man. - -The most famous and most interesting of these discoveries is the -fossil ape-man of Java, the much-talked-of _pithecanthropus erectus_, -found by a Dutch military doctor, Eugen Dubois, in 1894. It is in -truth the much-sought "missing link," supposed to be wanting in -the chain of primates, which stretches unbroken from the lowest -catarrhinæ to the highest-developed man. I have dealt exhaustively -with the significance of this discovery in the paper which I read on -August 26, 1898, at the Fourth International Zoological Congress at -Cambridge.[13] The palæontologist, who knows the conditions of the -formation and preservation of fossils, will think the discovery of the -pithecanthropus an unusually lucky accident. The apes, being arboreal, -seldom came into the circumstances (unless they happened to fall into -the water) which would secure the preservation and petrifaction of -their skeleton. Thus, by the discovery of this fossil man-monkey of -Java the descent of man from the ape has become just as clear and -certain from the palæontological side as it was previously from the -evidence of comparative anatomy and ontogeny. We now have all the -principal documents which tell the history of our race. - - - - -CHAPTER VI - -THE NATURE OF THE SOUL - - Fundamental Importance of Psychology--Its Definition and - Methods--Divergence of Views Thereon--Dualistic and Monistic - Psychology--Relation to the Law of Substance--Confusion - of Ideas--Psychological Metamorphoses: Kant, Virchow, - Du Bois-Reymond--Methods of Research of Psychic - Science--Introspective Method (Self-Observation)--Exact - Method (Psycho-Physics)--Comparative Method (Animal - Psychology)--Psychological Change of Principles: - Wundt--Folk-Psychology and Ethnography: Bastian--Ontogenetic - Psychology: Preyer--Phylogenetic Psychology: Darwin, Romanes - - -The phenomena which are comprised under the title of the "life of -the soul," or the psychic activity, are, on the one hand, the most -important and interesting, on the other the most intricate and -problematical, of all the phenomena we are acquainted with. As the -knowledge of nature, the object of the present philosophic study, -is itself a part of the life of the soul, and as anthropology, and -even cosmology, presuppose a correct knowledge of the "psyche," we -may regard psychology, the scientific study of the soul, both as the -foundation and the postulate of all other sciences. From another -point of view it is itself a part of philosophy, or physiology, or -anthropology. - -The great difficulty of establishing it on a naturalistic basis -arises from the fact that psychology, in turn, presupposes a correct -acquaintance with the human organism, especially the brain, the chief -organ of psychic activity. The great majority of "psychologists" have -little or no acquaintance with these anatomical foundations of the -soul, and thus it happens that in no other science do we find such -contradictions and untenable notions as to its proper meaning and -its essential object as are current in psychology. This confusion -has become more and more palpable during the last thirty years, in -proportion as the immense progress of anatomy and physiology has -increased our knowledge of the structure and the functions of the chief -psychic organ. - -What we call the soul is, in my opinion, a natural phenomenon; I -therefore consider psychology to be a branch of natural science--a -section of physiology. Consequently, I must emphatically assert -from the commencement that we have no different methods of research -for that science than for any of the others; we have in the first -place observation and experiment, in the second place the theory of -evolution, and in the third place metaphysical speculation, which -seek to penetrate as far as possible into the cryptic nature of the -phenomena by inductive and deductive reasoning. However, with a view -to a thorough appreciation of the question, we must first of all put -clearly before the reader the antithesis of the dualistic and the -monistic theories. - -The prevailing conception of the psychic activity, which we contest, -considers soul and body to be two distinct entities. These two -entities can exist independently of each other; there is no intrinsic -necessity for their union. The organized body is a mortal, material -nature, chemically composed of living protoplasm and its compounds -(plasma-products). The soul, on the other hand, is an immortal, -immaterial being, a spiritual agent, whose mysterious activity -is entirely incomprehensible to us. This trivial conception is, -as such, spiritualistic, and its contradictory is, in a certain -sense, materialistic. It is, at the same time, supernatural and -transcendental, since it affirms the existence of forces which can -exist and operate without a material basis; it rests on the assumption -that outside of and beyond nature there is a "spiritual," immaterial -world, of which we have no experience, and of which we can learn -nothing by natural means. - -This hypothetical "spirit world," which is supposed to be entirely -independent of the material universe, and on the assumption of which -the whole artificial structure of the dualistic system is based, is -purely a product of poetic imagination; the same must be said of the -parallel belief in the "immortality of the soul," the scientific -impossibility of which we must prove more fully later on (chap. xi.). -If the beliefs which prevail in these credulous circles had a sound -foundation, the phenomena they relate to could not be subject to the -"law of substance"; moreover, this single exception to the highest -law of the cosmos must have appeared very late in the history of the -organic world, since it only concerns the "soul" of man and of the -higher animals. The dogma of "free will," another essential element -of the dualistic psychology, is similarly irreconcilable with the -universal law of substance. - -Our own naturalistic conception of the psychic activity sees in it a -group of vital phenomena, which are dependent on a definite material -substratum, like all other phenomena. We shall give to this material -basis of all psychic activity, without which it is inconceivable, -the provisional name of "psychoplasm"; and for this good reason--that -chemical analysis proves it to be a body of the group we call -protoplasmic bodies the albuminoid carbon-combinations which are at -the root of all vital processes. In the higher animals, which have a -nervous system and sense-organs, "neuroplasm," the nerve-material, -has been differentiated out of psychoplasm. Our conception is, in -this sense, materialistic. It is at the same time empirical and -naturalistic, for our scientific experience has never yet taught us the -existence of forces that can dispense with a material substratum, or of -a spiritual world over and above the realm of nature. - -Like all other natural phenomena, the psychic processes are subject to -the supreme, all-ruling law of substance; not even in this province -is there a single exception to this highest cosmological law (compare -chap. xii.). The phenomena of the lowly psychic life of the unicellular -protist and the plant, and of the lowest animal forms--their -irritability, their reflex movements, their sensitiveness and instinct -of self-preservation--are directly determined by physiological action -in the protoplasm of their cells--that is, by physical and chemical -changes which are partly due to heredity and partly to adaptation. -And we must say just the same of the higher psychic activity of the -higher animals and man, of the formation of ideas and concepts, of -the marvellous phenomena of reason and consciousness; for the latter -have been phylogenetically evolved from the former, and it is merely -a higher degree of integration or centralization, of association -or combination of functions which were formerly isolated, that has -elevated them in this manner. - -The first task of every science is the clear definition of the object -it has to investigate. In no science, however, is this preliminary -task so difficult as in psychology; and this circumstance is the -more remarkable since logic, the science of defining, is itself a -part of psychology. When we compare all that has been said by the -most distinguished philosophers and scientists of all ages on the -fundamental idea of psychology, we find ourselves in a perfect chaos -of contradictory notions. What, really, is the "soul"? What is its -relation to the "mind"? What is the inner meaning of "consciousness"? -What is the difference between "sensation" and "sentiment"? What is -"instinct"? What is the meaning of "free will"? What is "presentation"? -What is the difference between "intellect" and "reason"? What is the -true nature of "emotion"? What is the relation between all these -"psychic phenomena" and the "body"? The answers to these and many other -cognate questions are infinitely varied; not only are the views of the -most eminent thinkers on these questions widely divergent, but even the -same scientific authority has often completely changed his views in the -course of his psychological development. Indeed, this "psychological -metamorphosis" of so many thinkers has contributed not a little to the -_colossal confusion of ideas_ which prevails in psychology more than in -any other branch of knowledge. - -The most interesting example of such an entire change of objective -and subjective psychological opinions is found in the case of the -most influential leader of German philosophy, Immanuel Kant. The -young, severely _critical_ Kant came to the conclusion that the three -great buttresses of mysticism--"God, freedom, and immortality"--were -untenable in the light of "pure reason"; the older, _dogmatic_ Kant -found that these three great hallucinations were postulates of -"practical reason," and were, as such, indispensable. The more the -distinguished modern school of "Neokantians" urges a "return to Kant" -as the only possible salvation from the frightful jumble of modern -metaphysics, the more clearly do we perceive the undeniable and fatal -contradiction between the fundamental opinions of the young and the -older Kant. We shall return to this point later on. - -Other interesting examples of this change of views are found in two of -the most famous living scientists, R. Virchow and E. du Bois-Reymond; -the metamorphoses of their fundamental views on psychology cannot -be overlooked, as both these Berlin biologists have played a most -important part at Germany's greatest university for more than forty -years, and have, therefore, directly and indirectly, had a most -profound influence on the modern mind. Rudolph Virchow, the eminent -founder of cellular pathology, was a _pure monist_ in the best days of -his scientific activity, about the middle of the century; he passed at -that time as one of the most distinguished representatives of the newly -awakened _materialism_, which appeared in 1855, especially through two -famous works, almost contemporaneous in appearance--Ludwig Büchner's -_Matter and Force_ and Carl Vogt's _Superstition and Science_. Virchow -published his general biological views on the vital processes in -man--which he takes to be purely mechanical natural phenomena--in a -series of distinguished papers in the first volumes of the _Archiv -für pathologische Anatomie_, which he founded. The most important of -these articles, and the one in which he most clearly expresses his -monistic views of that period, is that on "The Tendencies Towards -Unity in Scientific Medicine" (1849). It was certainly not without -careful thought, and a conviction of its philosophic value, that -Virchow put this "medical confession of faith" at the head of his -_Collected Essays on Scientific Medicine_ in 1856. He defended in it, -clearly and definitely, the fundamental principles of monism, which I -am presenting here with a view to the solution of the world-problem; -he vindicated the exclusive title of empirical science, of which the -only reliable sources are sense and brain activity; he vigorously -attacked anthropological dualism, the alleged "revelation," and -the transcendental philosophy, with their two methods--"faith and -anthropomorphism." Above all, he emphasized the monistic character of -anthropology, the inseparable connection of spirit and body, of force -and matter. "I am convinced," he exclaims, at the end of his preface, -"that I shall never find myself compelled to deny the thesis of _the -unity_ of human nature." Unhappily, this "conviction" proved to be a -grave error. Twenty-eight years afterwards Virchow represented the -diametrically opposite view; it is to be found in the famous speech on -"The Liberty of Science in Modern States," which he delivered at the -Scientific Congress at Munich in 1877, and which contains attacks that -I have repelled in my _Free Science and Free Teaching_ (1878). - -In Emil du Bois-Reymond we find similar contradictions with regard -to the most important and fundamental theses of philosophy. The -more completely the distinguished orator of the Berlin Academy had -defended the main principles of the monistic philosophy, the more he -had contributed to the refutation of vitalism and the transcendental -view of life, so much the louder was the triumphant cry of our -opponents when in 1872, in his famous _Ignorabimus-Speech_, he spoke -of consciousness as an insoluble problem, and opposed it to the other -functions of the brain as a supernatural phenomenon. I return to the -point in the tenth chapter. - -The peculiar character of many of the psychic phenomena, especially -of consciousness, necessitates certain modifications of our ordinary -scientific methods. We have, for instance, to associate with the -customary _objective_, external observation, the _introspective_ -method, the _subjective_, internal observation which scrutinizes -our own personality in the mirror of consciousness. The majority of -psychologists have started from this "certainty of the ego": "_Cogito -ergo sum_," as Descartes said--I think, therefore I am. Let us first -cast a glance at this way of inquiry, and then deal with the second, -complementary, method. - -By far the greater part of the theories of the soul which have been -put forward during the last two thousand years or more are based on -introspective inquiry--that is, on "self-observation," and on the -conclusions which we draw from the association and criticism of these -subjective experiences. Introspection is the only possible method of -inquiry for an important section of psychology, especially for the -study of consciousness. Hence this cerebral function occupies a special -position, and has been a more prolific source of philosophic error than -any of the others (cf. chap. x.). It is, however, most unsatisfactory, -and it leads to entirely false or incomplete notions, to take this -self-observation of the mind to be the chief, or, especially, to be -the only source of mental science, as has happened in the case of -many and distinguished philosophers. A great number of the principal -psychic phenomena, particularly the activity of the senses and speech, -can only be studied in the same way as every other vital function of -the organism--that is, firstly, by a thorough anatomical study of -their organs, and, secondly, by an exact physiological analysis of -the functions which depend on them. In order, however, to complete -this external study of the mental life, and to supplement the results -of _internal_ observation, one needs a thorough knowledge of human -anatomy, histology, ontogeny, and physiology. Most of our so-called -"psychologists" have little or no knowledge of these indispensable -foundations of anthropology; they are, therefore, incompetent to -pronounce on the character even of their own "soul." It must be -remembered, too, that the distinguished personality of one of these -psychologists usually offers a specimen of an educated mind of the -highest civilized races; it is the last link of a long ancestral chain, -and the innumerable older and inferior links are indispensable for -its proper understanding. Hence it is that most of the psychological -literature of the day is so much waste paper. The introspective method -is certainly extremely valuable and indispensable; still it needs the -constant co-operation and assistance of the other methods. - -In proportion as the various branches of the human tree of knowledge -have developed during the century, and the methods of the different -sciences have been perfected, the desire has grown to make them -_exact_; that is, to make the study of phenomena as purely empirical -as possible, and to formulate the laws that result as clearly as -the circumstances permit--if possible, _mathematically_. The latter -is, however, only feasible in a small province of human knowledge, -especially in those sciences in which there is question of measurable -quantities; in mathematics, in the first place, and to a greater or -less extent in astronomy, mechanics, and a great part of physics and -chemistry. Hence these studies are called "exact sciences" in the -narrower sense. It is, however, productive only of error to call all -the physical sciences _exact_, and oppose them to the historical, -mental, and moral sciences. The greater part of physical science can -no more be treated as an _exact_ science than history can; this is -especially true of biology and of its subsidiary branch, psychology. -As psychology is a part of physiology, it must, as a general rule, -follow the chief methods of that science. It must establish the facts -of psychic activity by empirical methods as much as possible, by -observation and experiment, and it must then gather the laws of the -mind by inductive and deductive inferences from its observations, -and formulate them with the utmost distinctness. But, for obvious -reasons, it is rarely possible to formulate them mathematically. Such -a procedure is only profitable in one section of the physiology of -the senses; it is not practicable in the greater part of cerebral -physiology. - -One small section of physiology, which seems amenable to the "exact" -method of investigation, has been carefully studied for the last -twenty years and raised to the position of a separate science under -the title of _psycho-physics_. Its founders, the physiologists Theodor -Fechner and Ernst Heinrich Weber, first of all closely investigated -the dependence of sensations on the external stimuli that act on the -organs of sense, and particularly the quantitative relation between -the strength of the stimulus and the intensity of the sensation. They -found that a certain minimum strength of stimulus is requisite for -the excitement of a sensation, and that a given stimulus must be -varied to a definite amount before there is any perceptible change -in the sensation. For the highest sensations (of sight, hearing, and -pressure) the law holds good that their variations are proportionate -to the changes in the strength of the stimulus. From this empirical -"law of Weber" Fechner inferred, by mathematical operations, his -"fundamental law of psycho-physics," according to which the intensity -of a sensation increases in arithmetical progression, the strength -of the stimulus in geometrical progression. However, Fechner's law -and other psycho-physical laws are frequently contested, and their -"exactness" is called into question. In any case modern psycho-physics -has fallen far short of the great hopes with which it was greeted -twenty years ago; the field of its applicability is extremely limited. -One important result of its work is that it has proved the application -of physical laws in one, if only a small, branch of the life of the -"soul"--an application which was long ago postulated on principle by -the materialist psychology for the whole province of mental life. In -this, as in many other branches of physiology, the "exact" method has -proved inadequate and of little service. It is the ideal to aim at -everywhere, but it is unattainable in most cases. Much more profitable -are the comparative and genetic methods. - -The striking resemblance of man's psychic activity to that of -the higher animals--especially our nearest relatives among the -mammals--is a familiar fact. Most uncivilized races still make no -material distinction between the two sets of mental processes, as -the well-known animal fables, the old legends, and the idea of the -transmigration of souls prove. Even most of the philosophers of -classical antiquity shared the same conviction, and discovered no -essential qualitative difference, but merely a quantitative one, -between the soul of man and that of the brute. Plato himself, who was -the first to draw a fundamental distinction between soul and body, -made one and the same soul (or "idea") pass through a number of animal -and human bodies in his theory of metempsychosis. It was Christianity, -intimately connecting faith in immortality with faith in God, that -emphasized the essential difference of the immortal soul of man from -the mortal soul of the brute. In the dualistic philosophy the idea -prevailed principally through the influence of Descartes (1643); -he contended that man alone had a true "soul," and, consequently, -sensation and free will, and that the animals were mere automata, or -machines, without will or sensibility. Ever since the majority of -psychologists--including even Kant--have entirely neglected the mental -life of the brute, and restricted psychological research to man: -human psychology, mainly introspective, dispensed with the fruitful -comparative method, and so remained at that lower point of view which -human morphology took before Cuvier raised it to the position of a -"philosophic science" by the foundation of comparative anatomy. - -Scientific interest in the psychic activity of the brute was revived -in the second half of the last century, in connection with the -advance of systematic zoology and physiology. A strong impulse was -given to it by the work of Reimarus: "General observations on the -instincts of animals" (Hamburg, 1760). At the same time a deeper -scientific investigation had been facilitated by the thorough reform -of physiology by Johannes Müller. This distinguished biologist, having -a comprehensive knowledge of the whole field of organic nature, of -morphology, and of physiology, introduced the "exact methods" of -observation and experiment into the whole province of physiology, and, -with consummate skill, combined them with the comparative methods. He -applied them, not only to mental life in the broader sense (to speech, -senses, and brain-action), but to all the other phenomena of life. The -sixth book of his _Manual of Human Physiology_ treats specially of the -life of the soul, and contains eighty pages of important psychological -observations. - -During the last forty years a great number of works on comparative -animal psychology have appeared, principally occasioned by the great -impulse which Darwin gave in 1859 by his work on _The Origin of -Species_, and by the application of the idea of evolution to the -province of psychology. The more important of these works we owe to -Romanes and Sir J. Lubbock, in England; to W. Wundt, L. Büchner, G. -Schneider, Fritz Schultze, and Karl Groos, in Germany; to Alfred -Espinas and E. Jourdan, in France; and to Tito Vignoli, in Italy. - -In Germany, Wilhelm Wundt, of Leipzig, is considered to be the ablest -living psychologist; he has the inestimable advantage over most other -philosophers of a thorough zoological, anatomical, and physiological -education. Formerly assistant and pupil of Helmholtz, Wundt had early -accustomed himself to follow the application of the laws of physics and -chemistry through the whole field of physiology, and, consequently, -in the sense of Johannes Müller, in _psychology_, as a subsection -of the latter. Starting from this point of view, Wundt published -his valuable "Lectures on human and animal psychology" in 1863. He -proved, as he himself tells us in the preface, that the theatre of -the most important psychic processes is in the "unconscious soul," -and he affords us "a view of the mechanism which, in the unconscious -background of the soul, manipulates the impressions which arise -from the external stimuli." What seems to me, however, of special -importance and value in Wundt's work is that he "extends the law of the -persistence of force for the first time to the psychic world, and makes -use of a series of facts of electro-physiology by way of demonstration." - -Thirty years afterwards (1892) Wundt published a second, much -abridged and entirely modified, edition of his work. The important -principles of the first edition are entirely abandoned in the second, -and the monistic is exchanged for a purely dualistic stand-point. -Wundt himself says in the preface to the second edition that he has -emancipated himself from the fundamental errors of the first, and -that he "learned many years ago to consider the work a sin of his -youth"; it "weighed on him as a kind of crime, from which he longed -to free himself as soon as possible." In fact, the most important -systems of psychology are completely opposed to each other in the two -editions of Wundt's famous _Observations_. In the first edition he -is purely monistic and materialistic, in the second edition purely -dualistic and spiritualistic. In the one psychology is treated as a -_physical_ science, on the same laws as the whole of physiology, of -which it is only a part; thirty years afterwards he finds psychology -to be a _spiritual_ science, with principles and objects entirely -different from those of physical science. This conversion is most -clearly expressed in his principle of psycho-physical parallelism, -according to which "every psychic event has a corresponding physical -change"; but the two are completely independent, and are not in any -natural causal connection. This complete dualism of body and soul, -of nature and mind, naturally gave the liveliest satisfaction to the -prevailing school-philosophy, and was acclaimed by it as an important -advance, especially seeing that it came from a distinguished scientist -who had previously adhered to the opposite system of monism. As I -myself continue, after more than forty years' study, in this "narrow" -position, and have not been able to free myself from it in spite of -all my efforts, I must naturally consider the "youthful sin" of the -young physiologist Wundt to be a correct knowledge of nature, and -energetically defend it against the antagonistic view of the old -philosopher Wundt. - -This entire change of philosophical principles, which we find in Wundt, -as we found it in Kant, Virchow, Du Bois-Reymond, Karl Ernst Baer, and -others, is very interesting. In their youth these able and talented -scientists embrace the whole field of biological research in a broad -survey, and make strenuous efforts to find a unifying, natural basis -for their knowledge; in their later years they have found that this is -not completely attainable, and so they entirely abandon the idea. In -extenuation of these psychological metamorphoses they can, naturally, -plead that in their youth they overlooked the difficulties of the great -task, and misconceived the true goal; with the maturer judgment of age -and the accumulation of experience they were convinced of their errors, -and discovered the true path to the source of truth. On the other hand, -it is possible to think that great scientists approach their task with -less prejudice and more energy in their earlier years--that their -vision is clearer and their judgment purer; the experiences of later -years sometimes have the effect, not of enriching, but of disturbing, -the mind, and with old age there comes a gradual decay of the brain, -just as happens in all other organs. In any case, this change of views -is in itself an instructive psychological fact; because, like many -other forms of change of opinion, it shows that the highest psychic -functions are subject to profound individual changes in the course of -life, like all the other vital processes. - -For the profitable construction of comparative psychology it is -extremely important not to confine the critical comparison to man -and the brute in general, but to put side by side the innumerable -gradations of their mental activity. Only thus can we attain a clear -knowledge of the long scale of psychic development which runs unbroken -from the lowest, unicellular forms of life up to the mammals, and to -man at their head. But even within the limits of our own race such -gradations are very noticeable, and the ramifications of the "psychic -ancestral tree" are very numerous. The psychic difference between the -crudest savage of the lowest grade and the most perfect specimen of -the highest civilization is colossal--much greater than is commonly -supposed. By the due appreciation of this fact, especially in the -latter half of the century, the "Anthropology of the uncivilized races" -(Waitz) has received a strong support, and comparative ethnography has -come to be considered extremely important for psychological purposes. -Unfortunately, the enormous quantity of raw material of this science -has not yet been treated in a satisfactory critical manner. What -confused and mystic ideas still prevail in this department may be seen, -for instance, in the _Völkergedanke_ of the famous traveller, Adolf -Bastian, who, though a prolific writer, merely turns out a hopeless -mass of uncritical compilation and confused speculation. - -The most neglected of all psychological methods, even up to the present -day, is the evolution of the soul; yet this little-frequented path -is precisely the one that leads us most quickly and securely through -the gloomy primeval forest of psychological prejudices, dogmas, and -errors, to a clear insight into many of the chief psychic problems. As -I did in the other branch of organic evolution, I again put before the -reader the two great branches of the science which I differentiated in -1866--ontogeny and phylogeny. The ontogeny, or embryonic development, -of the soul, individual or biontic psychogeny, investigates the gradual -and hierarchic development of the soul in the individual, and seeks to -learn the laws by which it is controlled. For a great part of the life -of the mind a good deal has been done in this direction for centuries; -rational pedagogy must have set itself the task at an early date of the -theoretical study of the gradual development and formative capacity of -the young mind that was committed to it for education and formation. -Most pedagogues, however, were idealistic or dualistic philosophers, -and so they went to work with all the prejudices of the spiritualistic -psychology. It is only in the last few decades that this dogmatic -tendency has been largely superseded even in the school by scientific -methods; we now find a greater concern to apply the chief laws of -evolution even in the discussion of the soul of the child. The raw -material of the child's soul is already qualitatively determined by -_heredity_ from parents and ancestors; education has the noble task of -bringing it to a perfect maturity by intellectual instruction and moral -training--that is, by _adaptation_. Wilhelm Preyer was the first to -lay the foundation of our knowledge of the early psychic development -in his interesting work on _The Mind of the Child_. Much is still to -be done in the study of the later stages and metamorphoses of the -individual soul, and once more the correct, critical application of the -biogenetic law is proving a guiding star to the scientific mind. - -A new and fertile epoch of higher development dawned for psychology -and all other biological sciences when Charles Darwin applied the -principles of evolution to them forty years ago. The seventh chapter -of his epoch-making work on _The Origin of Species_ is devoted to -instinct. It contains the valuable proof that the instincts of animals -are subject, like all other vital processes, to the general laws of -historic development. The special instincts of particular species were -formed by _adaptation_, and the modifications thus acquired were handed -on to posterity by _heredity_; in their formation and preservation -natural selection plays the same part as in the transformation of -every other physiological function. Darwin afterwards developed this -fundamental thought in a number of works, showing that the same laws of -"mental evolution" hold good throughout the entire organic world, not -less in man than in the brute, and even in the plant. Hence the unity -of the organic world, which is revealed by the common origin of its -members, applies also to the entire province of psychic life, from the -simplest unicellular organism up to man. - -To George Romanes we owe the further development of Darwin's -psychology and its special application to the different sections of -psychic activity. Unfortunately, his premature decease prevented the -completion of the great work which was to reconstruct every section -of comparative psychology on the lines of monistic evolution. The -two volumes of this work which were completed are among the most -valuable productions of psychological literature. For, conformably -to the principles of our modern monistic research, his first care -was to collect and arrange all the important facts which have been -empirically established in the field of comparative psychology in the -course of centuries; in the second place, these facts are tested with -an _objective criticism_, and systematically distributed; finally, such -rational conclusions are drawn from them on the chief general questions -of psychology as are in harmony with the fundamental principles of -modern monism. The first volume of Romanes's work bears the title -of _Mental Evolution in the Animal World_; it presents, in natural -connection, the entire length of the chain of psychic evolution in the -animal world, from the simplest sensations and instincts of the lowest -animals to the elaborate phenomena of consciousness and reason in the -highest. It contains also a number of extracts from a manuscript which -Darwin left "on instinct," and a complete collection of all that he -wrote in the province of psychology. - -The second and more important volume of Romanes's work treats of -"Mental evolution in man and the origin of human faculties." The -distinguished psychologist gives a convincing proof in it "that the -psychological barrier between man and the brute has been overcome." -Man's power of conceptual thought and of abstraction has been gradually -evolved from the non-conceptual stages of thought and ideation in the -nearest related mammals. Man's highest mental powers--reason, speech, -and conscience--have arisen from the lower stages of the same faculties -in our primate ancestors (the simiæ and prosimiæ). Man has no single -mental faculty which is his exclusive prerogative. His whole psychic -life differs from that of the nearest related mammals only in degree, -and not in kind; quantitatively, not qualitatively. - -I recommend those of my readers who are interested in these momentous -questions of psychology to study the profound work of Romanes. I am -completely at one with him and Darwin in almost all their views and -convictions. Wherever an apparent discrepancy is found between these -authors and my earlier productions, it is either a case of imperfect -expression on my part or an unimportant difference in application of -principle. For the rest, it is characteristic of this "science of -ideas" that the most eminent philosophers hold entirely antagonistic -views on its fundamental notions. - - - - -CHAPTER VII - -PSYCHIC GRADATIONS - - Psychological Unity of Organic Nature--Material Basis of the - Soul: Psychoplasm--Scale of Sensation--Scale of Movement--Scale - of Reflex Action--Simple and Compound Reflex Action--Reflex - Action and Consciousness--Scale of Perception--Unconscious and - Conscious Perception--Scale of Memory--Unconscious and Conscious - Memory--Association of Perceptions--Instinct--Primary and Secondary - Instincts--Scale of Reason--Language--Emotion and Passion--The - Will--Freedom of the Will - - -The great progress which psychology has made, with the assistance -of evolution, in the latter half of the century culminates in the -recognition of _the psychological unity of the organic world_. -Comparative psychology, in co-operation with the ontogeny and phylogeny -of the _psyche_, has enforced the conviction that organic life in all -its stages, from the simplest unicellular protozoon up to man, springs -from the same elementary forces of nature, from the physiological -functions of sensation and movement. The future task of scientific -psychology, therefore, is not, as it once was, the exclusively -subjective and introspective analysis of the highly developed mind -of a philosopher, but the objective, comparative study of the long -gradation by which man has slowly arisen through a vast series of lower -animal conditions. This great task of separating the different steps -in the psychological ladder, and proving their unbroken phylogenetic -connection, has only been seriously attempted during the last ten -years, especially in the splendid work of Romanes. We must confine -ourselves here to a brief discussion of a few of the general questions -which that gradation has suggested. - -All the phenomena of the psychic life are, without exception, bound -up with certain material changes in the living substance of the body, -the _protoplasm_. We have given to that part of the protoplasm which -seems to be the indispensable substratum of psychic life the name -of _psychoplasm_ (the "soul-substance," in the monistic sense); in -other words, we do not attribute any peculiar "essence" to it, but -we consider the _psyche_ to be merely _a collective idea of all the -psychic functions of protoplasm_. In this sense the "soul" is merely -a physiological abstraction like "assimilation" or "generation." In -man and the higher animals, in accordance with the division of labor -of the organs and tissues, the psychoplasm is a differentiated part of -the nervous system, the _neuroplasm_ of the ganglionic cells and their -fibres. In the lower animals, however, which have no special nerves -and organs of sense, and in the plants, the psychoplasm has not yet -reached an independent differentiation. Finally, in the unicellular -protists, the psychoplasm is identified either with the whole of the -living protoplasm of the simple cell or with a portion of it. In all -cases, in the lowest as well as the highest stages of the psychological -hierarchy, a certain chemical composition and a certain physical -activity of the psychoplasm are indispensable before the "soul" can -function or act. That is equally true of the elementary psychic -function of the plasmatic sensation and movement of the protozoa, -and of the complex functions of the sense-organs and the brain in the -higher animals and man. The activity of the psychoplasm, which we call -the "soul," is always connected with metabolism. - -All living organisms, without exception, are sensitive; they are -influenced by the condition of their environment, and react thereon by -certain modifications in their own structure. Light and heat, gravity -and electricity, mechanical processes and chemical action in the -environment, act as _stimuli_ on the sensitive psychoplasm, and effect -changes in its molecular composition. We may distinguish the following -five chief stages of this sensibility: - -I. At the lowest stage of organization the _whole psychoplasm_, as -such, is sensitive, and reacts on the stimuli from without; that is the -case with the lowest protists, with many plants, and with some of the -most rudimentary animals. - -II. At the second stage very simple and undiscriminating _sense-organs_ -begin to appear on the surface of the organism, in the form of -protoplasmic filaments and pigment spots, the forerunners of the nerves -of touch and the eyes; these are found in some of the higher protists -and in many of the lower animals and plants. - -III. At the third stage _specific organs_ of sense, each with a -peculiar adaptation, have arisen by differentiation out of these -rudimentary processes: there are the chemical instruments of smell -and taste, and the physical organs of touch, temperature, hearing, -and sight. The "specific energy" of these sense-organs is not an -original inherent property of theirs, but has been gained by functional -adaptation and progressive heredity. - -IV. The fourth stage is characterized by the _centralization_ or -integration of the _nervous system_, and, consequently, of sensation; -by the association of the previously isolated or localized sensations -presentations arise, though they still remain unconscious. That is the -condition of many both of the lower and the higher animals. - -V. Finally, at the fifth stage, the highest psychic function, -_conscious perception_, is developed by the mirroring of the sensations -in a central part of the nervous system, as we find in man and the -higher vertebrates, and probably in some of the higher invertebrates, -notably the articulata. - -All living organisms without exception have the faculty of _spontaneous -movement_, in contradistinction to the rigidity and inertia of -unorganized substances (_e.g._, crystals); in other words, certain -changes of place of the particles occur in the living psychoplasm -from internal causes, which have their source in its own chemical -composition. These active vital movements are partly discovered by -direct observation and partly only known indirectly, by inference from -their effects. We may distinguish five stages of them. - -I. At the lowest stage of organic life, in the chromacea, and many -protophyta and lower metaphyta, we perceive only those _movements of -growth_ which are common to all organisms. They are usually so slow -that they cannot be directly observed; they have to be inferred from -their results--from the change in size and form of the growing organism. - -II. Many protists, particularly unicellular algæ of the groups of -diatomacea and desmidiacea, accomplish a kind of creeping or swimming -motion by _secretion_, by ejecting a slimy substance at one side. - -III. Other organisms which float in water--for instance, many of the -radiolaria, siphonophora, ktenophora, and others--ascend and descend by -altering their _specific gravity_, sometimes by osmosis, sometimes by -the separation or squeezing-out of air. - -IV. Many plants, especially the sensitive plants (mimosa) and other -papilionacea, effect movements of their leaves or other organs by -_change of pressure_--that is, they alter the strain of the protoplasm, -and, consequently, its pressure on the enclosing elastic walls of the -cells. - -V. The most important of all organic movements are the _phenomena -of contraction_--_i.e._, changes of form at the surface of the -organism, which are dependent on a twofold displacement of their -elements; they always involve two different conditions or phases -of motion--contraction and expansion. Four different forms of this -plasmatic contraction may be enumerated: - - (_a_) Amoeboid movement (in rhizopods, blood-cells, - pigment-cells, etc.). - - (_b_) A similar flow of protoplasm within enclosed cells. - - (_c_) Vibratory motion (ciliary movements) in infusoria, - spermatozoa, ciliated epithelial cells. - - (_d_) Muscular movement (in most animals). - -The elementary psychic activity that arises from the combination of -sensation and movement is called _reflex_ (in the widest sense), -reflective function, or _reflex action_. The movement--no matter what -kind it is--seems in this case to be the immediate result of the -_stimulus_ which evoked the sensation; it has, on that account, been -called stimulated motion in its simplest form (in the protists). All -living protoplasm has this feature of irritability. Any physical or -chemical change in the environment may, in certain circumstances, -act as a stimulus on the psychoplasm, and elicit or "release" a -movement. We shall see later on how this important physical concept of -"releasing" directly connects the simplest organic reflex actions with -similar mechanical phenomena of movement in the inorganic world (for -instance, in the explosion of powder by a spark, or of dynamite by a -blow). We may distinguish the following seven stages in the scale of -reflex action: - -I. At the lowest stage of organization, in the lowest protists, the -stimuli of the outer world (heat, light, electricity, etc.) cause in -the indifferent protoplasm only those indispensable movements of growth -and nutrition which are common to all organisms, and are absolutely -necessary for their preservation. That is also the case in most of the -plants. - -II. In the case of many freely moving protists (especially the -amoeba, the heliozoon, and the rhizopod) the stimuli from without -produce on every spot of the unprotected surface of the unicellular -organism external movements which take the form of changes of shape, -and sometimes changes of place (amoeboid movement, pseudopod -formation, the extension and withdrawal of what look like feet); these -indefinite, variable processes of the protoplasm are not yet permanent -organs. In the same way, general organic irritability takes the form -of indeterminate reflex action in the sensitive plants and the lowest -metazoa; in many multicellular organisms the stimuli may be conducted -from one cell to another, as all the cells are connected by fine fibres. - -III. Many protists, especially the more highly developed protozoa, -produce on their unicellular body two little organs of the simplest -character--an organ of touch and an organ of movement. Both these -instruments are direct external projections of protoplasm; the -stimulus, which alights on the first, is immediately conducted to -the other by the psychoplasm of the unicellular body, and causes it -to contract. This phenomenon is particularly easy to observe, and -even produce experimentally, in many of the stationary infusoria -(for instance, the _poteriodendron_ among the flagellata, and the -_vorticella_ among the ciliata). The faintest stimulus that touches the -extremely sensitive hairs, or _cilia_, at the free end of the cells, -immediately causes a contraction of a thread-like stalk at the other, -fixed end. This phenomenon is known as a "simple reflex arch." - -IV. These phenomena of the unicellular organism of the infusoria lead -on to the interesting mechanism of the neuro-muscular cells, which we -find in the multicellular body of many of the lower metazoa, especially -in the cnidaria (polyps and corals). Each single neuro-muscular cell -is a "unicellular reflex organ"; it has on its surface a sensitive -spot, and a motor muscular fibre inside at the opposite end; the latter -contracts as soon as the former is stimulated. - -V. In other cnidaria, notably in the free swimming medusæ--which are -closely related to the stationary polyps--the simple neuro-muscular -cell becomes two different cells, connected by a filament; an external -_sense-cell_ (in the outer skin) and an internal _muscular cell_ (under -the skin). In this _bicellular reflex organ_ the one cell is the -rudimentary organ of sensation, the other of movement; the connecting -bridge of the psychoplasmic filament conducts the stimulus from one to -the other. - -VI. The most important step in the gradual construction of the reflex -mechanism is the division into three cells; in the place of the simple -connecting bridge we spoke of there appears a third independent cell, -the _soul-cell_, or ganglionic cell; with it appears also a new psychic -function, _unconscious presentation_, which has its seat in this -cell. The stimulus is first conducted from the sensitive cell to this -intermediate presentative or psychic cell, and then issued from this to -the motor muscular cell as a mandate of movement. These _tricellular -reflex organs_ are preponderantly developed in the great majority of -the invertebrates. - -VII. Instead of this arrangement we find in most of the vertebrates -a _quadricellular reflex organ_, two distinct "soul-cells," instead -of one, being inserted between the sensitive cell and the motor cell. -The external stimulus, in this case, is first conducted centripetally -to the sensitive cell (the sensible psychic cell), from this to the -_will-cell_ (the motor psychic cell), and from this, finally, to the -contractile muscular cell. When many such reflex organs combine and new -psychic cells are interposed we have the intricate reflex mechanism of -man and the higher vertebrates. - -The important distinction which we make, in morphology and physiology, -between unicellular and multicellular organisms holds good for their -elementary psychic activity, reflex action. In the unicellular -protists (both the plasmodomous primitive plants, or _protophyta_, -and the plasmophagous primitive animals, or _protozoa_) the whole -physical process of reflex action takes place in the protoplasm of -one single cell; their "cell-soul" seems to be a unifying function -of the psychoplasm of which the various phases only begin to be seen -separately when the differentiation of special organs sets in. - -The second stage of psychic activity, compound reflex action, begins -with the cenobitic protists (_v.g._, the volvox and the carchesium). -The innumerable social cells, which make up this cell-community -or coenobium, are always more or less connected, often directly -connected by filamentous bridges of protoplasm. A stimulus that alights -on one or more cells of the community is communicated to the rest by -means of the connecting fibres, and may produce a general contraction. -This connection is found, also, in the tissues of the multicellular -animals and plants. It was erroneously believed at one time that the -cells of vegetal tissue were completely isolated from each other, but -we have now discovered fine filaments of protoplasm throughout, which -penetrate the thick membranes of the cells, and maintain a material -and psychological communication between their living plasmic contents. -That is the explanation of the mimosa: when the tread of the passer-by -shakes the root of the plant, the stimulus is immediately conveyed to -all the cells, and causes a general contraction of its tender leaves -and a drooping of the stems. - -An important and universal feature of all reflex phenomena is the -absence of consciousness. For reasons which we shall give in the tenth -chapter we only admit the presence of consciousness in man and the -higher animals, not in plants, the lower animals, and the protists; -consequently all stimulated movements in the latter must be regarded -as reflex--that is, all movements which are not _spontaneous_, not the -outcome of internal causes (impulsive and automatic movements).[14] -It is different with the higher animals which have developed a -centralized nervous system and elaborate sense-organs. In these cases -consciousness has been gradually evolved from the psychic reflex -activity, and now conscious, voluntary action appears, in opposition to -the still continuing reflex action below. However, we must distinguish -two different processes, as we did in the question of instinct--primary -and secondary reflex action. Primary reflex actions are those which -have never reached the stage of consciousness in phyletic development, -and thus preserve the primitive character (by heredity from lower -animal forms). Secondary reflex actions are those which were conscious, -voluntary actions in our ancestors, but which afterwards became -unconscious from habit or the lapse of consciousness. It is impossible -to draw a hard and fast line in such cases between conscious and -unconscious psychic function. - -Older psychologists (Herbart, for instance) considered "presentation" -to be the fundamental psychic phenomenon, from which all the others are -derived. Modern comparative psychology endorses this view in so far as -it relates to the idea of _unconscious_ presentation; but it considers -_conscious_ presentation to be a secondary phenomenon of mental life, -which is entirely wanting in plants and the lower animals, and is -only developed in the higher animals. Among the many contradictory -definitions which psychologists have given of "presentation," we think -the best is that which makes it consist in an internal picture of the -external object which is given us in sensation--an "idea," in the -broader sense. We may distinguish the following four stages in the -rising scale of presentative function: - -I. _Cellular presentation._--At the lowest stages we find presentation -to be a general physiological property of psychoplasm; even in the -simplest unicellular protist sensations may leave a permanent trace in -the psychoplasm, and these may be reproduced by memory. In more than -four thousand kinds of radiolaria, which I have described, every single -species is distinguished by special, hereditary skeletal structure. The -construction of this specific, and often highly elaborate, skeleton -by a cell of the simplest description (generally globular) is only -intelligible when we attribute the faculty of presentation, and, -indeed, of a special reproduction of the plastic "feeling of distance," -to the constructive protoplasm--as I have pointed out in my _Psychology -of the Radiolaria_.[15] - -II. _Histionic presentation._--In the coenobia or cell-colonies of -the social protists, and still better in the tissues of plants and -lower, nerveless animals (sponges, polyps, etc.), we find the second -stage of unconscious presentation, which consists of the common psychic -activity of a number of closely connected cells. If a single stimulus -may, instead of simply spending itself in the reflex movement of an -organ (the leaf of a plant, for instance, or the arm of a polyp), -leave a permanent impression, which can be spontaneously reproduced -later on, we are bound to assume, in explaining the phenomenon, a -histionic presentation, dependent on the psychoplasm of the associated -tissue-cells. - -III. _Unconscious presentation in the ganglionic cells._--This -third and higher stage of presentation is the commonest form the -function takes in the animal world; it seems to be a localization of -presentation in definite "soul-cells." In its simplest form it appears -at the sixth stage of reflex action, when the tricellular reflex organ -arises: the seat of presentation is then the intermediate psychic -cell, which is interposed between the sensitive cell and the muscular -cell. With the increasing development of the animal nervous system -and its progressive differentiation and integration, this unconscious -presentation also rises to higher stages. - -IV. _Conscious presentation in the cerebral cells._--With the highest -stage of development of the animal organization consciousness arises, -as a special function of a certain central organ of the nervous -system. As the presentations are conscious, and as special parts of -the brain arise for the association of these conscious presentations, -the organism is qualified for those highest psychic functions which -we call thought and reflection, intellect and reason. Although the -tracing of the phyletic barrier between the older, unconscious, and the -younger, conscious, presentation is extremely difficult, we can affirm, -with some degree of probability, that the evolution of the latter from -the former was _polyphyletic_; because we find conscious and rational -thought, not only in the highest forms of the vertebrate stem (man, -mammals, birds, and a part of the lower vertebrates), but also in the -most highly developed representatives of other animal groups (ants -and other insects, spiders and the higher crabs among the articulata, -cephalopods among the mollusca). - -The evolutionary scale of memory is closely connected with that of -presentation; this extremely important function of the psychoplasm--the -condition of all further psychic development--consists essentially -in the _reproduction of presentations_. The impressions in the -bioplasm, which the stimulus produced as sensations, and which -became presentations in remaining, are revived by memory; they pass -from potentiality to actuality. The latent potential energy of the -psychoplasm is transformed into kinetic energy. We may distinguish -four stages in the upward development of memory, corresponding to the -four stages of presentation. - -I. _Cellular memory._--Thirty years ago Ewald Hering showed "memory to -be a general property of organized matter" in a thoughtful work, and -indicated the great significance of this function, "to which we owe -almost all that we are and have." Six years later, in my work on _The -Perigenesis of the Plastidule, or the Undulatory Origin of the Parts -of Life: an Experiment in the Mechanical Explanation of Elementary -Evolutionary Processes_, I developed these ideas, and endeavored -to base them on the principles of evolution. I have attempted to -show in that work that unconscious memory is a universal and very -important function of all _plastidules_; that is, of those hypothetical -molecules, or groups of molecules, which Naegeli has called _micellae_, -others _bioplasts_, and so forth. Only _living_ plastidules, as -individual molecules of the active protoplasm, are reproductive, -and so gifted with memory; that is the chief difference between the -organic and inorganic worlds. It might be stated thus: "Heredity is -the memory of the plastidule, while variability is its comprehension." -The elementary memory of the unicellular protist is made up of the -molecular memory of the plastidules or _micellae_, of which its living -cell-body is constructed. As regards the extraordinary performances -of unconscious memory in these unicellular protists, nothing could be -more instructive than the infinitely varied and regular formation of -their defensive apparatus, their shells and skeletons; in particular, -the diatomes and cosmaria among the protophytes, and the radiolaria -and thalamophora among the protozoa, afford an abundance of most -interesting illustrations. In many thousand species of these protists -the specific form which is inherited is _relatively constant_, and -proves the fidelity of their unconscious cellular memory. - -II. _Histionic memory._--Equally interesting examples of the second -stage of memory, the unconscious memory of tissues, are found in the -heredity of the individual organs of plants and the lower, nerveless -animals (sponges, etc.). This second stage seems to be _a reproduction -of the histionic presentations_, that association of cellular -presentations which sets in with the formation of coenobia in the -social protists. - -III. In the same way we must regard the third stage, the unconscious -memory of those animals which have a nervous system, as a reproduction -of the corresponding "unconscious presentations" which are stored up -in certain ganglionic cells. In most of the lower animals all memory -is unconscious. Moreover, even in man and the higher animals, to whom -we must ascribe consciousness, the daily acts of unconscious memory -are much more numerous and varied than those of the conscious faculty; -we shall easily convince ourselves of that if we make an impartial -study of a thousand unconscious acts we perform daily out of habit, and -without thinking of them, in walking, speaking, writing, eating, and so -forth. - -IV. Conscious memory, which is the work of certain brain-cells in -man and the higher animals, is an "internal mirroring" of very late -development, the highest outcome of the same psychic reproduction of -presentations which were mere unconscious processes in the ganglionic -cells of our lower animal ancestors. - -The concatenation of presentations--usually called the association of -ideas--also runs through a long scale, from the lowest to the highest -stages. This, too, is originally and predominantly unconscious -("instinct"); only in the higher classes of animals does it gradually -become conscious ("reason"). The psychic results of this "association -of ideas" are extremely varied; still, a very long, unbroken line of -gradual development connects the simplest unconscious association of -the lowest protist with the elaborate conscious chain of ideas of the -civilized man. The _unity of consciousness_ in man is given as its -highest consequence (Hume, Condillac). All higher mental activity -becomes more perfect in proportion as the normal association extends -to more numerous presentations, and in proportion to the order which -is imposed on them by the "criticism of pure reason." In dreams, -where this criticism is absent, the association of the reproduced -impressions often takes the wildest forms. Even in the work of the -poetic imagination, which constructs new groups of images by varying -the association of the impressions received, and in hallucinations, -etc., they are often most unnaturally arranged, and seem to the -prosaic observer to be perfectly irrational. This is especially true -of supernatural "forms of belief," the apparitions of spiritism, -and the fantastic notions of the transcendental dualist philosophy; -though it is precisely these _abnormal associations_ of "faith" and of -"revelation" that have often been deemed the greatest treasures of the -human mind (cf. chap. xvi.). - -The antiquated psychology of the Middle Ages (which, however, still -numbers many adherents) considered the mental life of man and that -of the brute to be two entirely different phenomena; the one it -attributed to "reason," the other to "instinct." In harmony with the -traditional story of creation, it was assumed that each animal species -had received a definite, unconscious psychic force from the Creator -at its formation, and that this instinct of each species was just as -unchangeable as its bodily structure. Lamarck proved the untenableness -of this error in 1809 by establishing the theory of Descent, and Darwin -completely demolished it in 1859. He proved the following important -theses with the aid of his theory of selection: - -1. The instincts of species show individual differences, and are -just as subject to modification under the law of _adaptation_ as the -morphological features of their bodily structure. - -2. These modifications (generally arising from a change of habits) are -partly transmitted to offspring by _heredity_, and thus accumulate and -are accentuated in the course of generations. - -3. _Selection_, both artificial and natural, singles out certain of -these inherited modifications of the psychic activity; it preserves the -most useful and rejects the least adaptive. - -4. The _divergence_ of psychic character which thus arises leads, in -the course of generations, to the formation of new instincts, just as -the divergence of morphological character gives rise to new species. - -Darwin's theory of instinct is now accepted by most biologists; Romanes -has treated it so ably, and so greatly expanded it in his distinguished -work on _Mental Evolution in the Animal World_, that I need merely -refer to it here. I will only venture the brief statement that, in my -opinion, there are instincts in _all_ organisms--in all the protists -and plants as well as in all the animals and in man; though in the -latter they tend to disappear in proportion as reason makes progress at -their expense. - -The two chief classes of instincts to be differentiated are the -primary and secondary. Primary instincts are the common lower -impulses which are unconscious and inherent in the psychoplasm -from the commencement of organic life; especially the impulses to -self-preservation (by defence and maintenance) and to the preservation -of the species (by generation and the care of the young). Both these -fundamental instincts of organic life, _hunger_ and _love_, sprang -up originally in perfect unconsciousness, without any co-operation -of the intellect or reason. It is otherwise with the _secondary_ -instincts. These were due originally to an intelligent adaptation, to -rational thought and resolution, and to purposive conscious action. -Gradually, however, they became so automatic that this "other nature" -acted unconsciously, and, even through the action of heredity, seemed -to be "innate" in subsequent generations. The consciousness and -deliberation which originally accompanied these particular instincts -of the higher animals and man have died away in the course of the -life of the plastidules (as in "abridged heredity"). The unconscious -purposive actions of the higher animals (for instance, their mechanical -instincts) thus come to appear in the light of innate impulses. We have -to explain in the same way the origin of the "_à priori_ ideas" of man; -they were originally formed empirically by his predecessors.[16] - -In the superficial psychological treatises which ignore the mental -activity of animals and attribute to man only a "true soul," we -find him credited also with the exclusive possession of reason and -consciousness. This is another trivial error (still to be found in many -a manual, nevertheless) which the comparative psychology of the last -forty years has entirely dissipated. The higher vertebrates (especially -those mammals which are most nearly related to man) have just as good a -title to "reason" as man himself, and within the limits of the animal -world there is the same long chain of the gradual development of -reason as in the case of humanity. The difference between the reason -of a Goethe, a Kant, a Lamarck, or a Darwin, and that of the lowest -savage, a Veddah, an Akka, a native Australian, or a Patagonian, is -much greater than the graduated difference between the reason of the -latter and that of the most "rational" mammals, the anthropoid apes, or -even the papiomorpha, the dog, or the elephant. This important thesis -has been convincingly proved by the thoroughly critical comparative -work of Romanes and others. We shall not, therefore, attempt to cover -that ground here, nor to enlarge on the distinction between the reason -and the intellect; as to the meaning and limits of these concepts -philosophic experts give the most contradictory definitions, as they do -on so many other fundamental questions of psychology. In general it may -be said that the process of the formation of concepts, which is common -to both these cerebral functions, is confined to the narrower circle of -concrete, proximate associations in the intellect, but reaches out to -the wider circle of abstract, more comprehensive groups of associations -in the work of reason. In the long gradation which connects the reflex -actions and the instincts of the lower animals with the reason of the -highest, intellect precedes the latter. And there is the fact, of -great importance to our whole psychological treatise, that even these -highest of our mental faculties are just as much subject to the laws -of heredity and adaptation as are their respective organs; Flechsig -pointed out in 1894 that the "organs of thought," in man and the higher -mammals, are those parts of the cortex of the brain which lie between -the four inner sense-centres (cf. chapters x. and xi.). - -The higher grade of development of ideas, of intellect and reason, -which raises man so much above the brute, is intimately connected with -the rise of language. Still here also we have to recognize a long chain -of evolution which stretches unbroken from the lowest to the highest -stages. Speech is no more an exclusive prerogative of man than reason. -In the wider sense, it is a common feature of all the higher gregarious -animals, at least of all the articulata and the vertebrates, which live -in communities or herds; they need it for the purpose of understanding -each other and communicating their impressions. This is effected either -by touch or by signs, or by sounds having a definite meaning. The -song of the bird or of the anthropoid ape (_hylobates_), the bark of -the dog, the neigh of the horse, the chirp of the cricket, the cry of -the cicada, are all specimens of animal speech. Only in man, however, -has that articulate conceptual speech developed which has enabled his -reason to attain such high achievements. Comparative philology, one -of the most interesting sciences that has arisen during the century, -has shown that the numerous elaborate languages of the different -nations have been slowly and gradually evolved from a few simple -primitive tongues (Wilhelm Humboldt, Bopp, Schleicher, Steinthal, and -others). August Schleicher, of Jena, in particular, has proved that -the historical development of language takes place under the same -phylogenetic laws as the evolution of other physiological faculties -and their organs. Romanes (1893) has expanded this proof, and amply -demonstrated that human speech, also, differs from that of the brute -only in _degree_ of development, not in essence and kind. - -The important group of psychic activities which we embrace under the -name of "emotion" plays a conspicuous part both in theoretical and -practical psychology. From our point of view they have a peculiar -importance from the fact that we clearly see in them the direct -connection of cerebral functions with other physiological functions -(the beat of the heart, sense-action, muscular movement, etc.); -they, therefore, prove the unnatural and untenable character of -the philosophy which would essentially dissociate psychology from -physiology. All the external expressions of emotional life which we -find in man are also present in the higher animals (especially in the -anthropoid ape and the dog); however varied their development may be, -they are all derived from the two elementary functions of the _psyche_, -sensation and motion, and from their combination in reflex action and -presentation. To the province of sensation, in a wide sense, we must -attribute the feeling of _like_ and _dislike_ which determines the -emotion; while the corresponding _desire_ and _aversion_ (love and -hatred), the effort to attain what is liked and avoid what is disliked, -belong to the category of movement. "Attraction" and "repulsion" -seem to be the sources of _will_, that momentous element of the soul -which determines the character of the individual. The _passions_, -which play so important a part in the psychic life of man, are but -intensifications of emotion. Romanes has recently shown that these also -are common to man and the brute. Even at the lowest stage of organic -life we find in all the protists those elementary feelings of like -and dislike, revealing themselves in what are called their _tropisms_, -in the striving after light and darkness, heat or cold, and in their -different relations to positive and negative electricity. On the other -hand, we find at the highest stage of psychic life, in civilized man, -those finer shades of emotion, of delight and disgust, of love and -hatred, which are the mainsprings of civilization and the inexhaustible -sources of poetry. Yet a connecting chain of all conceivable gradations -unites the most primitive elements of feeling in the psychoplasm of the -unicellular protist with the highest forms of passion that rule in the -ganglionic cells of the cortex of the human brain. That the latter are -absolutely amenable to physical laws was proved long ago by the great -Spinoza in his famous _Statics of Emotion_. - -The notion of _will_ has as many different meanings and definitions -as most other psychological notions--presentation, soul, mind, and -so forth. Sometimes will is taken in the widest sense as a _cosmic -attribute_, as in the "World as will and presentation" of Schopenhauer; -sometimes it is taken in its narrowest sense as an _anthropological -attribute_, the exclusive prerogative of man--as Descartes taught, for -instance, who considered the brute to be a mere machine, without will -or sensation. In the ordinary use of the term, _will_ is derived from -the phenomenon of voluntary movement, and is thus regarded as a psychic -attribute of most animals. But when we examine the will in the light of -comparative physiology and evolution, we find--as we do in the case of -sensation--that it is a universal property of living psychoplasm. The -automatic and the reflex movements which we observe everywhere, even -in the unicellular protists, seem to be the outcome of inclinations -which are inseparably connected with the very idea of life. Even in the -plants and lowest animals these inclinations, or tropisms, seem to be -the joint outcome of the inclinations of all the combined individual -cells. - -But when the "tricellular reflex organ" arises (page 115), and a third -independent cell--the "psychic," or "ganglionic," cell--is interposed -between the sense-cell and the motor cell, we have an independent -elementary organ of will. In the lower animals, however, this will -remains _unconscious_. It is only when consciousness arises in the -higher animals, as the subjective mirror of the objective, though -internal, processes in the neuroplasm of the psychic cells, that the -will reaches that highest stage which likens it in character to the -human will, and which, in the case of man, assumes in common parlance -the predicate of "liberty." Its free dominion and action become more -and more deceptive as the muscular system and the sense-organs develop -with a free and rapid locomotion, entailing a correlative evolution of -the brain and the organs of thought. - -The question of the liberty of the will is the one which has more than -any other cosmic problem occupied the time of thoughtful humanity, -the more so that in this case the great philosophic interest of the -question was enhanced by the association of most momentous consequences -for practical philosophy--for ethics, education, law, and so forth. -Emil du Bois-Reymond, who treats it as the seventh and last of his -"seven cosmic problems," rightly says of the question: "Affecting -everybody, apparently accessible to everybody, intimately involved in -the fundamental conditions of human society, vitally connected with -religious belief, this question has been of immeasurable importance -in the history of civilization. There is probably no other object -of thought on which the modern library contains so many dusty folios -that will never again be opened." The importance of the question is -also seen in the fact that Kant put it in the same category with the -questions of the immortality of the soul and belief in God. He called -these three great questions the indispensable "postulates of practical -reason," though he had already clearly shown them to have no reality -whatever in the light of _pure_ reason. - -The most remarkable fact in connection with this fierce and confused -struggle over the freedom of the will is, perhaps, that it has been -theoretically rejected, not only by the greatest critical philosophers, -but even by their extreme opponents, and yet it is still affirmed to -be self-evident by the majority of people. Some of the first teachers -of the Christian Churches--such as St. Augustine and Calvin--rejected -the freedom of the will as decisively as the famous leaders of pure -materialism, Holbach in the eighteenth and Büchner in the nineteenth -century. Christian theologians deny it, because it is irreconcilable -with their belief in the omnipotence of God and in predestination. God, -omnipotent and omniscient, saw and willed all things from eternity--he -must, consequently, have predetermined the conduct of man. If man, with -his free will, were to act otherwise than God had ordained, God would -not be all-mighty and all-knowing. In the same sense Leibnitz, too, -was an unconditional determinist. The monistic scientists of the last -century, especially Laplace, defended determinism as a consequence of -their mechanical view of life. - -The great struggle between the determinist and the indeterminist, -between the opponent and the sustainer of the freedom of the will, -has ended to-day, after more than two thousand years, completely in -favor of the determinist. The human will has no more freedom than that -of the higher animals, from which it differs only in degree, not in -kind. In the last century the dogma of liberty was fought with general -philosophic and cosmological arguments. The nineteenth century has -given us very different weapons for its definitive destruction--the -powerful weapons which we find in the arsenal of comparative physiology -and evolution. We now know that each act of the will is as fatally -determined by the organization of the individual and as dependent on -the momentary condition of his environment as every other psychic -activity. The character of the inclination was determined long ago -by _heredity_ from parents and ancestors; the determination to each -particular act is an instance of _adaptation_ to the circumstances of -the moment wherein the strongest motive prevails, according to the laws -which govern the statics of emotion. Ontogeny teaches us to understand -the evolution of the will in the individual child. Phylogeny reveals -to us the historical development of the will within the ranks of our -vertebrate ancestors. - - - - -CHAPTER VIII - -THE EMBRYOLOGY OF THE SOUL - - Importance of Ontogeny to Psychology--Development of the - Child-Soul--Commencement of Existence of the Individual - Soul--The Storing of the Soul--Mythology of the Origin of - the Soul--Physiology of the Origin of the Soul--Elementary - Processes in Conception--Coalescence of the Ovum and - the Spermatozoon--Cell-Love--Heredity of the Soul from - Parents and Ancestors--Its Physiological Nature as the - Mechanics of the Protoplasm--Blending of Souls (Psychic - Amphigony)--Reversion, Psychological Atavism--The Biogenetic - Law in Psychology--Palingenetic Repetition and Cenogenetic - Modification--Embryonic and Post-Embryonic Psychogeny - - -The human soul--whatever we may hold as to its nature--undergoes -a continual development throughout the life of the individual. -This ontogenetic fact is of fundamental importance in our monistic -psychology, though the "professional" psychologists pay little or no -attention to it. Since the embryology of the individual is, on Baer's -principle--and in accordance with the universal belief of modern -biologists--the "true torch-bearer for all research into the organic -body," it will afford us a reliable light on the momentous problems of -its psychic activity. - -Although, however, this "embryology of the soul" is so important and -interesting, it has hitherto met with the consideration it deserves -only within a very narrow circle. Until recently teachers were almost -the only ones to occupy themselves with a part of the problem; -since their avocation compelled them to assist and supervise the -formation of the psychic activity in the child, they were bound to -take a theoretical interest, also, in the psychogenetic facts that -came under their notice. However, these teachers, for the most part, -both in recent and in earlier times, were dominated by the current -dualistic psychology--in so far as they reflected at all; and they were -totally ignorant of the important facts of comparative psychology, and -unacquainted with the structure and function of the brain. Moreover, -their observations only extended to children in their school-days, or -in the years immediately preceding. The remarkable phenomena which -the individual psychogeny of the child offers in its earliest years, -and which are the joy and admiration of all thoughtful parents, were -scarcely ever made the subject of serious scientific research. Wilhelm -Preyer was the pioneer of this study in his interesting work on _The -Mind of the Child_ (1881). To obtain a perfectly clear knowledge of the -matter, however, we must go further back still; we must commence at the -first appearance of the soul in the impregnated ovum. - -The origin of the human individual--body and soul--was still wrapped -in complete mystery at the beginning of the nineteenth century. Caspar -Friedrich Wolff had, it is true, discovered the true character of -embryonic development in 1759, in his _theoria generationis_, and -proved with the confidence of a critical observer that there is a -true _epigenesis_--_i.e._, a series of very remarkable formative -processes--in the evolution of the foetus from the simple ovum. But -the physiologists of the time, with the famous Albert Haller at their -head, flatly refused to entertain these empirical truths, which may be -directly proved by microscopic observation, and clung to the old dogma -of "preformation." This theory assumed that in the human ovum--and in -the egg of all other animals--the organism was already present, or -"preformed," in all its parts; the "evolution" of the embryo consisted -literally in an "unfolding" (_evolutio_) of the folded organs. One -curious consequence of this error was the theory of _scatulation_, -which we have mentioned on p. 55; since the ovary had to be admitted to -be present in the embryo of the woman, it was also necessary to suppose -that the germs of the next generation were already formed in it, and -so on _in infinitum_. Opposed to this dogma of the "Ovulists" was -the equally erroneous notion of the "Animalculists"; the latter held -that the germ was not really in the female ovum, but in the paternal -element, and that the store of succeeding generations was to be sought -in the spermatozoa. - -Leibnitz consistently applied this theory of scatulation to the human -soul; he denied that either soul or body had a real development -(_epigenesis_), and said in his _Theodicy_: "Thus I consider that the -souls which are destined one day to become human exist in the seed, -like those of other species; that they have existed in our ancestors -as far back as Adam--that is, since the beginning of the world--in -the forms of organized bodies." Similar notions prevailed in biology -and philosophy until the third decade of the present century, when -the reform of embryology by Baer gave them their death blow. In the -province of psychology, however, they still find many adherents; they -form one group of the many curious mystical ideas which give us a -living illustration of the ontogeny of the soul. - -The more accurate knowledge which we have recently obtained, through -comparative ethnology, of the various forms of myths of ancient and -modern uncivilized races, is also of great interest in psychogeny. -Still, it would take us too far from our purpose if we were to enter -into it with any fulness here; we must refer the reader to Adalbert -Svoboda's excellent work on _Forms of Faith_ (1897). In respect of -their scientific and poetical contents, we may arrange all pertinent -_psychogenetic myths_ in the following five groups: - -I. The myth of transmigration.--The soul lived formerly in the body of -another animal, and passed from this into a human body. The Egyptian -priests, for instance, taught that the human soul wandered through all -the species of animals after the death of the body, returning to a -human frame after three thousand years of transmigration. - -II. The myth of the in-planting of the soul.--The soul existed -independently in another place--a psychogenetic store, as it were (in a -kind of embryonic slumber or latent life); it was taken out by a bird -(sometimes represented as an eagle, generally as a white stork), and -implanted in the human body. - -III. The myth of the creation of the soul.--God creates the souls, -and keeps them stored--sometimes in a pond (living in the form of -_plankton_), according to other myths in a tree (where they are -conceived as the fruit of a phanerogam); the Creator takes them from -the pond or tree, and inserts them in the human germ during the act of -conception. - -IV. The myth of the scatulation of the soul (the theory of Leibnitz -which we have given above). - -V. The myth of the division of the soul (the theory of Rudolph Wagner -[1855] and of other physiologists).--In the act of procreation a -portion is detached from both the (immaterial) souls of the parents; -the maternal contribution passes in the ovum, the paternal in the -spermatozoa; when these two germinal cells coalesce, the two psychic -fragments that accompany them also combine to form a new (immaterial) -soul. - -Although the poetic fancies we have mentioned as to the origin of -the individual human soul are still widely accepted, their purely -mythological character is now firmly established. The deeply -interesting and remarkable research which has been made in the course -of the last twenty-five years into the more minute processes of the -impregnation and germination of the ovum has made it clear that these -mysterious phenomena belong entirely to the province of cellular -physiology (cf. p. 48). Both the female element, the ovum, and the male -fertilizing body, the sperma or spermatozoa, are _simple cells_. These -living cells possess a certain sum of physiological properties to which -we give the title of the "cell-soul," just as we do in the permanently -unicellular protist (see p. 48). Both germinal cells have the faculty -of movement and sensation. The young ovum, or egg-cell, moves after -the manner of an amoeba; the minute spermatozoa, of which there are -millions in every drop of the seminal fluid, are ciliated cells, and -swim about as freely in the sperm, by means of their lashes or _cilia_, -as the ordinary ciliated infusoria (the flagellata). - -When the two cells meet as a result of copulation, or when they are -brought into contact through artificial fertilization (in the fishes, -for instance), they attract each other and become firmly attached. The -main cause of this cellular attraction is a chemical sensitive action -of the protoplasm, allied to smell or taste, which we call "erotic -chemicotropism"; it may also be correctly (both in the chemical and -the romantic sense) termed "cellular affinity" or "sexual cell-love." -A number of the ciliated cells in the sperm swim rapidly towards the -stationary egg-cell and seek to penetrate into it. As Hertwig showed in -1875, as a rule only one of the suitors is fortunate enough to reach -the desired goal. As soon as this favored spermatozoon has pierced -into the body of the ovum with its head (the nucleus of the cell), a -thin mucous layer is detached from the ovum which prevents the further -entrance of spermatozoa. The formation of this protective membrane -was only prevented when Hertwig kept the ovum stiff with cold by -lowering the temperature, or benumbed it with narcotics (chloroform, -morphia, nicotine, etc.); then there was "super-impregnation" or -"poly-spermy"--a number of sperm-threads pierced into the body of -the unconscious ovum. This remarkable fact proved that there is a -low degree of "cellular instinct" (or, at least, of specific, lively -sensation) in the sexual cells just as effectively as do the important -phenomena that immediately follow in their interior. Both nuclei--that -of the ovum and of the spermatozoon--attract each other, approach, and, -on contact, completely fuse together. Thus from the impregnated ovum -arises the important new cell which we call the "stem-cell" (_cytula_), -from the repeated segmentation of which the whole polycellular organism -is evolved. - -The psychological information which is afforded by these remarkable -facts of impregnation, which have only been properly observed -during the last twenty-five years, is supremely important; its vast -significance has hitherto been very far from appreciated. We shall -condense the main conclusions of research in the following five theses: - -I. Each human individual, like every other higher animal, is a single -simple cell at the commencement of his existence. - -II. This "stem-cell" (cytula) is formed in the same manner in all -cases--that is, by the blending or copulation of two separate cells of -diverse origin, the female ovum and the male spermatozoon. - -III. Each of these sexual cells has its own "cell-soul"--that is, each -is distinguished by a peculiar form of sensation and movement. - -IV. At the moment of conception or impregnation, not only the -protoplasm and the nuclei of the two sexual cells coalesce, but also -their "cell-souls"; in other words, the potential energies which are -latent in both, and inseparable from the matter of the protoplasm, -unite for the formation of a new potential energy, the "germ-soul" of -the newly constructed stem-cell. - -V. Consequently each personality owes his bodily and spiritual -qualities to both parents; by heredity the nucleus of the ovum -contributes a portion of the maternal features, while the nucleus of -the spermatozoon brings a part of the father's characteristics. - -By these empirical facts of conception, moreover, the further fact of -extreme importance is established, that every man, like every other -animal, _has a beginning of existence_; the complete copulation of -the two sexual cell-nuclei marks the precise moment when not only the -body, but also the "soul," of the new stem-cell makes its appearance. -This fact suffices of itself to destroy the myth of the immortality -of the soul, to which we shall return later on. It suffices, too, for -the destruction of the still prevalent superstition that man owes -his personal existence to the favor of God. Its origin is rather to -be attributed solely to the "eros" of his parents, to that powerful -impulse that is common to all polycellular animals and plants, -and leads to their nuptial union. But the essential point in this -physiological process is not the "embrace," as was formerly supposed, -or the amorousness connected therewith; it is simply the introduction -of the spermatozoa into the vagina. This is the sole means, in the -land-dwelling animals, by which the fertilizing element can reach the -released ova (which usually takes place in the uterus in man). In the -case of the lower aquatic animals (fishes, mussels, medusæ, etc.) the -mature sexual elements on both sides are simply discharged into the -water, and their union is let to chance; they have no real copulation, -and so they show none of those higher psychic "erotic" functions which -play so conspicuous a part in the life of the higher animals. Hence -it is, also, that all the lower, non-copulating animals are wanting -in those interesting organs which Darwin has called "secondary sexual -characters," and which are the outcome of sexual selection: such are -the beard of man, the antlers of the stag, the beautiful plumage of -the bird of paradise and of so many other birds, together with other -distinctions of the male which are absent in the female. - -Among the above theses as to the physiology of conception the -inheritance of the psychic qualities of the two parents is of -particular importance for psychological purposes. It is well known that -every child inherits from both his parents peculiarities of character, -temperament, talent, acuteness of sense, and strength of will. It -is equally well known that even psychic qualities are often (if not -always) transmitted from grandparents by heredity--often, in fact, -a man resembles his grandparents more than his parents in certain -respects; and that is true both of bodily and mental features. All -the chief laws of heredity which I first formulated in my _General -Morphology_, and popularized in my _Natural History of Creation_, are -just as valid and universal in their application to psychic phenomena -as to bodily structure--in fact, they are frequently more striking and -conspicuous in the former than in the latter. - -However, the great province of heredity, to the inestimable importance -of which Darwin first opened our eyes in 1859, is thickly beset with -obscure problems and physiological difficulties. We dare not claim, -even after forty years of research, that all its aspects are clear -to us. Yet we have done so much that we can confidently speak of -heredity as a _physiological function_ of the organism, which is -directly connected with the faculty of generation; and we must reduce -it, like all other vital phenomena, to exclusively physical and -chemical processes, to the _mechanics of the protoplasm_. We now know -accurately enough the process of impregnation itself; we know that in -it the nucleus of the spermatozoon contributes the qualities of the -male parent, and the nucleus of the ovum gives the qualities of the -mother, to the newly born stem-cell. The blending of the two nuclei is -the "physiological moment" of heredity; by it the personal features of -both body and soul are transmitted to the new individual. These facts -of ontogeny are beyond the explanation of the dualistic and mystic -psychology which still prevails in the schools; whereas they find a -perfectly simple interpretation in our monistic philosophy. - -The physiological fact which is most material for a correct appreciation -of individual psychogeny is the _continuity_ of the _psyche_ through -the rise and fall of generations. A new individual comes into -existence at the moment of conception; yet it is not an independent -entity, either in respect of its mental or its bodily features, but -merely the product of the blending of the two parental factors, the -maternal egg-cell and paternal sperm-cell. The cell-souls of these -two sexual cells combine in the act of conception for the formation -of a new cell-soul, just as truly as the two cell-nuclei, which are -the material vehicles of this psychic potential energy, unite to form -a new nucleus. As we now see that the individuals of one and the same -species--even sisters born of the same parents--always show certain -differences, however slight, we must assume that these variations -were already present in the chemical plasmatic constitution of the -generative cells themselves.[17] - -These facts alone would suffice to explain the infinite variety of -individual features, of soul and of bodily form, that we find in the -organic world. As an extreme, but one-sided, consequence of them, there -is the theory of Weismann, which considers the _amphimixis_, or the -blending of the germ-plasm in sexual generation, to be the universal -and the sole cause of individual variability. This exclusive theory, -which is connected with his theory of the continuity of the germ-plasm, -is, in my opinion, an exaggeration. I am convinced, on the contrary, -that the great laws of _progressive heredity_ and of the correlative -_functional adaptation_ apply to the soul as well as to the body. The -new characteristics which the individual has acquired during life may -react to some extent on the molecular texture of the germ-plasm in -the egg-cell and sperm-cell, and may thus be transferred to the next -generation by heredity in certain conditions (naturally, only in the -form of latent energy). - -Although in the soul-blending at the moment of conception only -the latent forces of the two parent souls are transmitted by the -coalescence of the erotic cell-nuclei, still it is possible that the -hereditary psychic influence of earlier, and sometimes very much -older, generations may be communicated at the same time. For the laws -of _latent heredity_ or atavism apply to the soul just as validly as -to the anatomical organization. We find these remarkable phenomena of -reversion in a very simple and instructive form in the alternation of -generations of the polyps and medusæ. Here we see two very different -generations alternate so regularly that the first resembles the third, -fifth, and so on; while the second (very different from the preceding) -is like the fourth, sixth, etc. (_Natural History of Creation_). We do -not find such alternation of generations in man and the higher animals -and plants, in which, owing to continuous heredity, each generation -resembles the next; nevertheless, even in these cases we often meet -with phenomena of reversion, which must be reduced to the same law of -latent heredity. - -Eminent men often take more after their grandparents than their parents -even in the finer shades of psychic activity--in the possession of -certain artistic talents or inclinations, in force of character, and -in warmth of temperament; not infrequently there is a striking feature -which neither parents nor grandparents possessed, but which may be -traced a long way back to an older branch of the family. Even in -these remarkable cases of atavism the same laws of heredity apply to -the _psyche_ and to the physiognomy, to the personal quality of the -sense-organs, muscles, skeleton, and other parts of the body. We can -trace them most clearly in the reigning dynasties and in old families -of the nobility, whose conspicuous share in the life of the State has -given occasion to a more careful historical picture of the individuals -in the chain of generations--for instance, in the Hohenzollerns, the -princes of Orange, the Bourbons, etc., and in the Roman Cæsars. - -The causal-nexus of _biontic_ (individual) and _phyletic_ (historical) -evolution, which I gave in my _General Morphology_ as the supreme law -at the root of all biogenetic research, has a universal application to -psychology no less than to morphology. I have fully treated the special -importance which it has with regard to man, in both respects, in the -first chapter of my _Anthropogeny_. In man, as in all other organisms, -"the embryonic development is an epitome of the historical development -of the species. This condensed and abbreviated recapitulation is the -more complete in proportion as the original _epitomized development_ -(_palingenesis_) is preserved by a constant heredity; on the other -hand, it falls off from completeness in proportion as the later -_disturbing development_ (_cenogenesis_) is accentuated by varying -adaptation." - -While we apply this law to the evolution of the soul, we must lay -special stress on the injunction to keep _both_ sides of it critically -before us. For, in the case of man, just as in all the higher animals -and plants, such appreciable perturbations of type (or _cenogeneses_) -have taken place during the millions of years of development that -the original simple idea of _palingenesis_, or "epitome of history," -has been greatly disturbed and altered. While, on the one side, the -_palingenetic_ recapitulation is preserved by the laws of like-time -and like-place heredity, it is subject to an essential _cenogenetic_ -change, on the other hand, by the laws of abbreviated and simplified -heredity. That is clearly seen in the embryonic evolution of the -psychic organs, the nervous system, the muscles, and the sense-organs. -But it applies in just the same manner to the psychic functions, which -are absolutely dependent on the normal construction of these organs. -Their evolution is subject to great cenogenetic modification in man -and all other viviparous animals, precisely because the complete -development of the embryo occupies a longer time within the body of -the mother. But we have to distinguish two periods of individual -psychogeny: (1) the embryonic, and (2) the post-embryonic development -of the soul. - -I. _Embryonic Psychogeny._--The human foetus, or embryo, normally -takes nine months (or two hundred and seventy days) to develop in -the uterus. During this time it is entirely cut off from the outer -world, and protected, not only by the thick muscular wall of the womb, -but also by the special foetal membranes (_embryolemmata_) which -are common to all the three higher classes of vertebrates--reptiles, -birds, and mammals. In all the classes of amniotes these membranes -(the _amnion_ and the _serolemma_) develop in just the same fashion. -They represent the protective arrangements which were acquired by -the earliest reptiles (_proreptilia_), the common parents of all the -amniotes, in the Permian period (towards the end of the palæozoic -age), when these higher vertebrates accustomed themselves to live on -land and breathe the atmosphere. Their ancestors, the amphibia of the -Carboniferous period, still lived and breathed in the water, like their -earlier predecessors, the fishes. - -In the case of these older and lower vertebrates that lived in the -water, the embryonic development had the palingenetic character in -a still higher degree, as is the case in most of the fishes and -amphibia of the present day. The familiar tadpole and the larva of -the salamander or the frog still preserve the structure of their -fish-ancestors in the first part of their life in the water; they -resemble them, likewise, in their habits of life, in breathing by -gills, in the action of their sense-organs, and in other psychic -organs. Then, when the interesting metamorphosis of the swimming -tadpole takes place, and when it adapts itself to a land-life, the -fish-like body changes into that of a four-footed, crawling amphibium; -instead of the gill-breathing in the water comes an exclusive -breathing of the atmosphere by means of lungs, and, with the changed -habits of life, even the psychic apparatus, the nervous system, and -the sense-organs reach a higher degree of construction. If we could -completely follow the psychogeny of the tadpole from beginning to end, -we should be able to apply the biogenetic law in many ways to its -psychic evolution. For it develops in direct communication with the -changing conditions of the outer world, and so must quickly adapt its -sensation and movement to these. The swimming tadpole has not only the -structure but the habits of life of a fish, and only acquires those of -a frog in its metamorphosis. - -It is different with man and all the other amniotes; their embryo is -entirely withdrawn from the direct influence of the outer world, and -cut off from any reciprocal action therewith, by enclosure in its -protective membranes. Besides, the special care of the young on the -part of the amniotes gives their embryo much more favorable conditions -for the cenogenetic abbreviation of the palingenetic evolution. There -is, in the first place, the excellent arrangement for the nourishment -of the embryo; in the reptiles, birds, and monotremes (the oviparous -mammals) it is effected by the great yellow nutritive yelk, which is -associated with the egg; in the rest of the mammals (the marsupials and -placentals) it is effected by the mother's blood, which is conducted to -the foetus by the blood-vessels of the yelk-sac and the allantois. -In the case of the most highly developed placentals this elaborate -nutritive arrangement has reached the highest degree of perfection by -the construction of a placenta; hence in these classes the embryo is -fully developed before birth. But its soul remains during all this time -in a state of embryonic slumber, a state of repose which Preyer has -justly compared to the hibernation of animals. We have a similar long -sleep in the chrysalis stage of those insects which undergo a complete -metamorphosis--butterflies, bees, flies, beetles, and so forth. This -sleep of the pupa, during which the most important formations of -organs and tissues take place, is the more interesting from the fact -that the preceding condition of the free larva (caterpillar, grub, or -maggot) included a highly developed psychic activity, and that this is, -significantly, lower than the stage which is seen afterwards (when the -chrysalis sleep is over) in the perfect, winged, sexually mature insect. - -Man's psychic activity, like that of most of the higher animals, runs -through a long series of stages of development during the individual -life. We may single out the five following as the most important of -them: - -I. The soul of the new-born infant up to the birth of self-consciousness -and the learning of speech. - -II. The soul of the boy or girl up to puberty (_i.e._, until the -awakening of the sexual instinct). - -III. The soul of the youth or maiden up to the time of sexual -intercourse (the "idealist" period). - -IV. The soul of the grown man and the mature woman (the period of -full maturity and of the founding of families, lasting until about -the sixtieth year for the man and the fiftieth for the woman--until -_involution_ sets in). - -V. The soul of the old man or woman (the period of degeneration). - -Man's psychic life runs the same evolution--upward progress, full -maturity, and downward degeneration--as every other vital activity in -his organization. - - - - -CHAPTER IX - -THE PHYLOGENY OF THE SOUL - - Gradual Historical Evolution of the Human Soul from the Animal - Soul--Methods of Phylogenetic Psychology--Four Chief Stages in - the Phylogeny of the Soul: I. The Cell-Soul (Cytopsyche) of the - Protist (Infusoria, Ova, etc.): Cellular Psychology; II. The Soul - of a Colony of Cells, or the Cenobitic Soul (Coenopsyche): - Psychology of the Morula and Blastula; III. The Soul of the Tissue - (Histopsyche): Its Twofold Nature: The Soul of the Plant: The Soul - of the Lower, Nerveless Animal: Double Soul of the Siphonophora - (Personal and Kormal Soul); IV. The Nerve-Soul (Neuropsyche) - of the Higher Animal--Three Sections of its Psychic Apparatus: - Sense-Organs, Muscles, and Nerves--Typical Formation of the - Nerve-Centre in the Various Groups of Animals--Psychic Organ of the - Vertebrate: the Brain and the Spinal Cord--Phylogeny of the Mammal - Soul - - -The theory of descent, combined with anthropological research, has -convinced us of the descent of our human organism from a long series -of animal ancestors by a slow and gradual transformation occupying -many millions of years. Since, then, we cannot dissever man's psychic -life from the rest of his vital functions--we are rather forced to a -conviction of the natural evolution of our whole body and mind--it -becomes one of the main tasks of the modern monistic psychology to -trace the stages of the historical development of the soul of man from -the soul of the brute. Our "phylogeny of the soul" seeks to attain this -object; it may also, as a branch of general psychology, be called -_phylogenetic_ psychology, or, in contradistinction to _biontic_ -(individual), _phyletic psychogeny_. And, although this new science has -scarcely been taken up in earnest yet, and most of the "professional" -psychologists deny its very right to existence, we must claim for it -the utmost importance and the deepest interest. For, in our opinion, it -is its special province to solve for us the great enigma of the nature -and origin of the human soul. - -The methods and paths which will lead us to the remote goal of a -complete phylogenetic psychology--a goal that is still buried in the -mists of the future, and almost imperceptible to many--do not differ -from those of other branches of evolutionary research. Comparative -anatomy, physiology, and ontogeny are of the first importance. Much -support is given also by palæontology, for the order in which the -fossil remains of the various classes of vertebrates succeed each other -in the course of organic evolution reveals to us, to some extent, -the gradual growth of their psychic power as well as their phyletic -connection. We must admit that we are here, as we are in every branch -of phylogenetic research, driven to the construction of a number of -hypotheses in order to fill up the considerable lacunæ of empirical -phylogeny. Yet these hypotheses cast so clear and significant a light -on the chief stages of historical development that we are afforded a -most gratifying insight into their entire course. - -The comparative psychology of man and the higher animals enables us -to learn from the highest group of the placentals, the primates, the -long strides by which the human soul has advanced beyond the _psyche_ -of the anthropoid ape. The phylogeny of the mammals and of the lower -vertebrates acquaints us with the long series of the earlier ancestors -of the primates which have arisen within this stem since the Silurian -age. All these vertebrates agree in the structure and development of -their characteristic psychic organ--the spinal cord. We learn from -the comparative anatomy of the vermalia that this spinal cord has -been evolved from a dorsal _acroganglion_, or vertical brain, of an -invertebrate ancestor. We learn, further, from comparative ontogeny -that this simple psychic organ has been evolved from the stratum of -cells in the outer germinal layer, the ectoderm, of the platodes. In -these earliest flat-worms, which have no specialized nervous system, -the outer skin-covering serves as a general sensitive and psychic -organ. Finally, comparative embryology teaches us that these simple -metazoa have arisen by gastrulation from blastæades, from hollow -spheres, the wall of which is merely one simple layer of cells, the -_blastoderm_; and the same science, with the aid of the biogenetic law, -explains how these protozoic coenobia originally sprang from the -simplest unicellular organisms. - -On a critical study of these different embryonic formations, the -evolution of which from each other we can directly observe under the -microscope, we arrive, by means of the great law of biogeny, at a -series of most important conclusions as to the chief stages in the -development of our psychic life. We may distinguish eight of these to -begin with: - -I. Unicellular protozoa with a simple cell-soul: the infusoria. - -II. Multicellular protozoa with a communal soul: the catallacta. - -III. The earliest metazoa with an epithelial soul: the platodes. - -IV. Invertebrate ancestors with a simple vertical brain: the vermalia. - -V. Vertebrates without skull or brain, with a simple spinal cord: the -acrania. - -VI. Animals with skull and brain (of five vesicles): the craniota. - -VII. Mammals with predominant development of the cortex of the brain: -the placentals. - -VIII. The higher anthropoid apes and man, with organs of thought (in -the cerebrum): the anthropomorpha. - -Among these eight stages in the development of the human soul we may -further distinguish more or less clearly a number of subordinate -stages. Naturally, however, in reconstructing them we have to fall -back on the same defective evidence of empirical psychology which the -comparative anatomy and physiology of the actual fauna affords us. As -the craniote animals of the sixth stage--and these are true fishes--are -already found fossilized in the Silurian system, we are forced to -assume that the five preceding series of ancestors (which were -incapable of fossilization) were evolved in an earlier, pre-Silurian -age. - -I. _The cell-soul_ (_or cytopsyche_): first stage of phyletic -psychogenesis.--The earliest ancestors of man and all other animals -were unicellular protozoa. This fundamental hypothesis of rational -phylogeny is based, in virtue of the phylogenetic law, on the -familiar embryological fact that every man, like every other metazoon -(_i.e._, every multicellular organism with tissues), begins his -personal existence as a simple cell, the stem-cell (_cytula_), or the -impregnated egg-cell (see p. 63). As this cell has a "soul" from the -commencement, so had also the corresponding unicellular _ancestral -forms_, which were represented in the oldest series of man's ancestors -by a number of different protozoa. - -We learn the character of the psychic activity of these unicellular -organisms from the comparative physiology of the protists of to-day. -Close observation and careful experiment have opened out to us in this -respect, in the second half of the nineteenth century, a new world of -the most interesting phenomena. The best description of them was given -by Max Verworn in his thoughtful work, based on original research, -_Psycho-physiological Studies of the Protists_. The work includes also -the few earlier observations of the "psychic life of the protist." -Verworn came to the firm conclusion that the psychic processes are -unconscious in all the protists, that the phenomena of sensation -and movement coincide with the molecular vital processes in their -protoplasm, and that their ultimate causes are to be sought in the -properties of the protoplasmic molecules (the _plastidules_). "Hence -the psychic phenomena of the protists form a bridge that connects the -chemical processes of the inorganic world with the psychic life of -the highest animals; they represent the germ of the highest psychic -phenomena of the metazoa and of man." - -The careful observations and many experiments of Verworn, together -with those of Wilhelm Engelmann, Wilhelm Preyer, Richard Hertwig, and -other more recent students of the protists, afford conclusive evidence -for my "theory of the cell-soul" (1866). On the strength of several -years of study of different kinds of protists, especially rhizopods and -infusoria, I published a theory thirty-three years ago to the effect -that every living cell has psychic properties, and that the psychic -life of the multicellular animals and plants is merely the sum total of -the psychic functions of the cells which build up their structure. In -the lower groups (in algæ and sponges, for instance) _all_ the cells of -the body have an equal share in it (or with very slight differences); -in the higher groups, in harmony with the law of the "division of -labor," only a select portion of them are involved--the "soul-cells." -The important consequences of this "cellular psychology" were partly -treated in my work on _The Perigenesis of the Plastidule_ (1876), -and partly in my speech at Munich, in 1877, on "Modern Evolution in -Relation to the Whole of Science." A more popular presentation of -them is to be found in my two Vienna papers (1878) on "The Origin and -Development of the Sense-Organs" and on "Cell-Souls and Soul-Cells." - -Moreover, the cell-soul, even within the limits of the protist world, -presents a long series of stages of development, from the most simple -and primitive to a comparatively elaborate activity. In the earliest -and simplest protists the faculty of sensation and movement is equally -distributed over the entire protoplasm of the homogeneous morsel; in -the higher forms certain "cell-instruments," or _organella_, appear, -as their physiological organs. Motor cell-parts of that character are -found in the pseudopodia of the rhizopods, and the vibrating hairs, -lashes, or cilia of the infusoria. The cell-nucleus, which is wanting -in the earlier and lower protists, is considered to be an internal -central organ of the cell-life. It is especially noteworthy, from a -physiologico-chemical point of view, that the very earliest protists -were plasmodomous, with plant-like nutrition--hence _protophyta_, or -primitive plants; from these came as a secondary stage, by metasitism, -the first plasmophagi, with animal nutrition--the _protozoa_, or -primitive animals.[18] This metasitism, or circulation of nutritive -matter, implies an important psychological advance; with it began the -development of those characteristic properties of the animal soul which -are wanting in the plant. - -We find the highest development of the animal cell-soul in the class -of ciliata, or ciliated infusoria. When we compare their activity -with the corresponding psychic life of the higher, multicellular -animals, we find scarcely any psychological difference; the sensitive -and motor _organella_ of these protozoa seem to accomplish the same -as the sense-organs, nerves, and muscles of the metazoa. Indeed, we -have found in the great cell-nucleus (_meganucleus_) of the infusoria -a central organ of psychic activity, which plays much the same part -in their unicellular organism as the brain does in the psychic life -of higher animals. However, it is very difficult to determine how far -this comparison is justified; the views of experts diverge considerably -over the matter. Some take all spontaneous bodily movement in them to -be automatic, or impulsive, and all stimulated movement to be reflex; -others are convinced that such movements are partly voluntary and -intentional. The latter would attribute to the infusoria a certain -degree of consciousness, and even self-consciousness; but this is -rejected by the others. However that very difficult question may be -settled, it does not alter the fact that these unicellular protozoa -give proof of the possession of a highly developed "cell-soul," which -is of great interest for a correct decision as to the _psyche_ of our -earliest unicellular ancestors. - -II. _The communal or cenobitic soul_ (_coenopsyche_): second stage of -phyletic psychogenesis.--Individual development begins, in man and in -all other multicellular animals, with the repeated segmentation of one -simple cell. This _stem-cell_, the impregnated ovum, divides first into -two daughter cells, by a process of ordinary indirect segmentation; -as the process is repeated there arise (by equal division of the egg) -successively four, eight, sixteen, thirty-two, sixty-four such new -cells, or "blastomeres." Usually (that is, in the case of the majority -of animals) an irregular enlargement sooner or later takes the place -of this original regular division of cells. But the result is the same -in all cases--the formation of a (generally spherical) cluster of -heterogeneous (originally homogeneous) cells. This stage is called the -_morula_ ("mulberry," which it somewhat resembles in shape). Then, as -a rule, a fluid gathers in the interior of this aggregate of cells; it -changes into a spherical vesicle; all the cells go to its surface, and -arrange themselves in one simple layer--the _blastoderm_. The hollow -sphere which is thus formed is the important stage of the "germinal -vesicle," the _blastula_, or blastosphere. - -The psychological phenomena which we directly observe in the formation -of the blastula are partly sensations, partly movements, of this -community of cells. The movements may be divided into two groups: (1) -the inner movements, which are always repeated in substantially the -same manner in the process of ordinary (indirect) segmentation of -cells (formation of the axis of the nucleus, mitosis, karyokinesis, -etc.); (2) the outer movements, which are seen in the regular change of -position of the social cells and their grouping for the construction -of the blastoderm. We assume that these movements are hereditary and -unconscious, because they are always determined in the same fashion by -heredity from the earlier protist ancestors. The sensations also fall -into two groups: (1) the sensations of the individual cells, which -reveal themselves in the assertion of their individual independence and -their relation to neighboring cells (with which they are in contact, -and partly in direct combination, by means of protoplasmic fibres); (2) -the common sensation of the entire community of cells, which is seen in -the individual formation of the _blastula_ as a hollow vesicle. - -The causal interpretation of the formation of the blastula is given us -by the biogenetic law, which explains the phenomena we directly observe -to be the outcome of heredity, and relates them to corresponding -historical processes which took place long ago in the origin of the -earliest protist-coenobia, the blastæads. But we get a physiological -and psychological insight into these important phenomena of the -earliest cell-communities by observation and experiment on their modern -representatives. Such permanent cell-communities or colonies are still -found in great numbers both among the plasmodomous primitive plants -(for instance, the paulotomacea, diatomacea, volvocinæ, etc.) and the -plasmophagous primitive animals (the infusoria and rhizopods). In -all these coenobia we can easily distinguish two different grades -of psychic activity: (1) the cell-soul of the individual cells (the -"elementary organisms") and (2) the communal soul of the entire colony. - -III. _The tissue-soul_ (_histopsyche_): third stage of phyletic -psychogenesis.--In all multicellular, tissue-forming plants -(_metaphyta_) and in the lowest, nerveless classes of tissue-forming -animals (_metazoa_) we have to distinguish two different forms of -psychic activity--namely: (1) the _psyche_ of the individual cells -which compose the tissue, and (2) the _psyche_ of the tissue itself, or -of the "cell-state" which is made up of the tissues. This "tissue-soul" -is the higher psychological function which gives physiological -individuality to the compound multicellular organism as a true -"cell-commonwealth." It controls all the separate "cell-souls" of the -social cells--the mutually dependent "citizens" which constitute the -community. This fundamental twofold character of the _psyche_ in the -metaphyta and the lower, nerveless metazoa is very important. It may -be verified by unprejudiced observation and suitable experiment. In -the first place, each single cell has its own sensation and movement, -and, in addition, each tissue and each organ, composed of a number -of homogeneous cells, has its special irritability and psychic unity -(_e.g._, the pollen and stamens). - -A. _The plant-soul_ (_phytopsyche_) is, in our view, the summary of -the entire psychic activity of the tissue-forming, multicellular plant -(the _metaphyton_, as distinct from the unicellular _protophyton_); -it is, however, the subject of the most diverse opinions even at the -present day. It was once customary to draw an essential distinction -between the plant and the animal, on the ground that the latter had -a "soul" and the plant had none. However, an unprejudiced comparison -of the irritability and movements of various higher plants and lower -animals convinced many observers, even at the beginning of the century, -that there must be a "soul" on both sides. At a later date Fechner, -Leitgeb, and others strongly contended for the plant-soul. But a -profounder knowledge of the subject was obtained when the similarity -of the elementary structure of the plant and of the animal was proved -by the cellular theory, and especially when the similarity of conduct -of the active, living protoplasm in both was shown in the plasma -theory of Max Schultze (1859). Modern comparative physiology has -shown that the physiological attitude towards various stimuli (light, -heat, electricity, gravity, friction, chemical action, etc.) of the -"sensitive" portions of many plants and animals is exactly the same, -and that the reflex movements which the stimuli elicit take place in -precisely the same manner on both sides. Hence, if it was necessary to -attribute this activity to a "soul" in the lower, nerveless metazoa -(sponges, polyps, etc.), it was also necessary in the case of many -(if not all) metaphyta, at least in the very sensitive _mimosa_, the -"fly-traps" (_dionaea_ and _drosera_), and the numerous kinds of -climbing plants. - -It is true that modern vegetal physiology has given a purely physical -explanation of many of these stimulated movements, or tropisms, by -special features of growth, variations of pressure, etc. Yet these -mechanical causes are neither more nor less _psychophysical_ than -the similar "reflex movements" of the sponges, polyps, and other -nerveless metazoa, even though their mechanism is entirely different. -The character of the tissue-soul reveals itself in the same way in -both cases--the cells of the tissue (the regular, orderly structure -of cells) transmit the stimuli they have received in one part, and -thus provoke movements of other parts, or of the whole organ. This -transmission of stimuli has as much title to be called "psychic -activity" as its more complete form in the higher animals with nerves; -the anatomic explanation of it is that the social cells of the tissue, -or cell-community, are not isolated from each other (as was formerly -supposed), but are connected throughout by fine threads or bridges of -protoplasm. When the sensitive mimosa closes its graceful leaves and -droops its stalk at contact, or on being shaken; when the irritable -fly-trap (the dionæa) swiftly clasps its leaves together at a touch, -and captures a fly; the sensation seems to be keener, the transmission -of the stimulus more rapid, and the movement more energetic than in the -reflex action of the stimulated bath-sponge and many other sponges. - -B. _The soul of the nerveless metazoa._--Of very special interest for -comparative psychology in general, and for the phylogeny of the animal -soul in particular, is the psychic activity of those lower metazoa -which have tissues, and sometimes differentiated organs, but no nerves -or specific organs of sense. To this category belong four different -groups of the earliest coelenterates: (_a_) the gastræads, (_b_) the -platodaria, (_c_) the sponges, and (_d_) the hydropolyps, the lowest -form of cnidaria. - -The _gastraeads_ (or animals with a primitive gut) form a small group -of the lowest coelenterates, which is of great importance as the -common ancestral group of all the metazoa. The body of these little -swimming animals looks like a tiny (generally oval) vesicle, which has -a simple cavity with one opening--the primitive gut and the primitive -mouth. The wall of the digestive cavity is formed of two simple -layers of cells, or epithelium, the inner of which--the gut-layer--is -responsible for the vegetal activity of nourishment, while the outer, -or skin-layer, discharges the animal functions of movement and -sensation. The homogeneous sensitive cells of the skin-layer bear long, -slender hairs or lashes (_cilia_), by the vibration of which the -swimming motion is effected. The few surviving forms of gastræads, -the gastræmaria (_trichoplacidae_) and cyemaria (_orthonectidae_), -are extremely interesting, from the fact that they remain throughout -life at a stage of structure which is passed by all the other metazoa -(from the sponge to man) at the commencement of their embryonic -development. As I have shown in my _Theory of the Gastraea_ (1872), -a very characteristic embryonic form, the _gastrula_, is immediately -developed from the _blastula_ in all the tissue animals. The germinal -membrane (blastoderm), which represents the wall of the hollow vesicle, -forms a depression at one side, and this soon sinks in so deep that the -inner cavity of the vesicle disappears. The half of the membrane which -bends in is thus laid on, and inside, the other half; the latter forms -the _skin-layer_, or outer germinal layer (ectoderm or epiblast), and -the former becomes the _gut-layer_, or inner germinal layer (endoderm -or hypoblast). The new cavity of the cup-shaped body is the digestive -stomach cavity (the _progaste_), and its opening is the primitive mouth -(or _prostoma_).[19] The skin-layer, or ectoderm, is the primitive -psychic organ in the metazoa; from it, in all the nerve animals, not -only the external skin and the organs of sense, but also the nervous -system, are developed. In the gastræads, which have no nerves, all the -cells which compose the simple epithelium of the ectoderm are equally -organs of sensation and of movement; we have here the tissue-soul in -its simplest form. - -The platodaria, the earliest and simplest form of the platodes, seem to -be of the same primitive construction. Some of these cryptocoela--the -_convoluta_, etc.--have no specific nervous system, while their -nearest relatives, the turbellaria, have already differentiated one, -and even developed a vertical brain. - -The _sponges_ form a peculiar group in the animal world, which differs -widely in organization from all the other metazoa. The innumerable -kinds of sponges grow, as a rule, at the bottom of the sea. The -simplest form of sponge, the _olynthus_, is in reality nothing more -than a _gastraea_, the body-wall of which is perforated like a sieve, -with fine pores, in order to permit the entrance of the nourishing -stream of water. In the majority of sponges--even in the most familiar -one, the bath-sponge--the bulbous organism constructs a kind of stem or -tree, which is made up of thousands of these gastræads, and permeated -by a nutritive system of canals. Sensation and movement are only -developed in the faintest degree in the sponges; they have no nerves, -muscles, or organs of sense. It was therefore quite natural that such -stationary, shapeless, insensitive animals should have been commonly -taken to be plants in earlier years. Their psychic life--for which no -special organs have been differentiated--is far inferior to that of the -mimosa and other sensitive plants. - -_The soul of the cnidaria_ is of the utmost importance in comparative -and phylogenetic psychology; for in this numerous group of the -coelenterates the historical evolution of the _nerve-soul_ out of the -_tissue-soul_ is repeated before our eyes. To this group belong the -innumerable classes of stationary polyps and corals, and of swimming -medusæ and siphonophora. As the common ancestor of all the cnidaria -we can safely assign a very simple polyp, which is substantially -the same in structure as the common, still surviving, fresh-water -polyp--the hydra. Yet the hydræ, and the stationary, closely related -_hydropolyps_, have no nerves or higher sense-organs, although they -are extremely sensitive. On the other hand, the free-swimming medusæ, -which are developed from them--and are still connected with them -by alternation of generations--have an independent nervous system -and specific sense-organs. Here, also, we may directly observe the -ontogenetic evolution of the nerve-soul (_neuropsyche_) out of the -tissue-soul (_histopsyche_), and thus learn its phylogenetic origin. -This is the more interesting as such phenomena are _polyphyletic_--that -is, they have occurred several times--more than once, at least--quite -independently. As I have shown elsewhere, the hydromedusæ have arisen -from the hydropolyps in a different manner from that of the evolution -of the scyphomedusæ from the scyphopolyps; the gemmation is terminal in -the case of the latter, and lateral with the former. In addition, both -groups have characteristic hereditary differences in the more minute -structure of their psychic organs. The class of siphonophora is also -very interesting to the psychologist. In these pretty, free-swimming -organisms, which come from the hydromedusæ we can observe a double -soul: the _personal soul_ of the numerous individualities which compose -them, and the common, harmoniously acting psyche of the entire colony. - -IV. _The nerve-soul_ (_neuropsyche_): fourth stage of phyletic -psychogeny.--The psychic life of all the higher animals is conducted, -as in man, by means of a more or less complicated "psychic apparatus." -This apparatus is always composed of three chief sections: the _organs -of sense_ are responsible for the various sensations; the _muscles_ -effect the movements; the _nerves_ form the connection between the -two by means of a special central organ, the brain or ganglion. The -arrangement and action of this psychic mechanism have been frequently -compared with those of a telegraphic system: the nerves are the wires, -the brain the central, and the sense-organs subordinate stations. The -motor nerves conduct the commands of the will centrifugally from the -nerve-centre to the muscles, by the contraction of which they produce -the movements: the sensitive nerves transmit the various sensations -centripetally--that is, from the peripheral sense-organs to the -brain, and thus render an account of the impressions they receive -from the outer world. The ganglionic cells, or "psychic cells," which -compose the central nervous organ, are the most perfect of all organic -elements; they not only conduct the commerce between the muscles and -the organs of sense, but they also effect the highest performances of -the animal soul, the formation of ideas and thoughts, and especially -consciousness. - -The great progress of anatomy, physiology, histology, and ontogeny has -recently added a wealth of interesting discoveries to our knowledge of -the mechanism of the soul. If speculative philosophy assimilated only -the most important of these significant results of empirical biology, -it would have a very different character from that it unfortunately -presents. As I have not space for an exhaustive treatment of them here, -I will confine myself to a relation of the chief facts. - -Each of the higher animal species has a characteristic psychic organ; -the central nervous system of each has certain peculiarities of shape, -position, and composition. The medusæ, among the radiating cnidaria, -have a ring of nervous matter at the border of the fringe, generally -provided with four or eight ganglia. The mouth of the five-rayed -cnidarion is girt with a nerve-ring, from which proceed five branches. -The bi-symmetrical _platodes_ and the _vermalia_ have a vertical -brain, or acroganglion, composed of two dorsal ganglia, lying above -the mouth; from these "upper ganglia" two branch nerves proceed to the -skin and the muscles. In some of the vermalia and in the mollusca a -pair of ventral "lower ganglia" are added, which are connected with -the former by a ring round the gullet. This ring is found also in the -_articulata_; but in these it is continued on the belly side of the -long body as a ventral medulla, a double fibre like a rope-ladder, -which expands into a double ganglion in each member. The vertebrates -have an entirely different formation of the psychic organ; they have -always a spinal medulla developed at the back of the body; and from an -expansion of its fore part there arises subsequently the characteristic -vesicular brain.[20] - -Although the psychic organs of the higher species of animals differ -very materially in position, form, and composition, nevertheless -comparative anatomy is in a position to prove a common origin for most -of them--namely, from the vertical brain of the platodes and vermalia; -they have all, moreover, had their origin in the outermost layer of the -embryo, the _ectoderm_, or outer skin-layer. Hence we find the same -typical structure in all varieties of the central nervous organ--a -combination of ganglionic cells, or "psychic cells" (the real active -elementary organs of the soul), and of nerve-fibres, which effect the -connection and transmission of the action. - -The first fact we meet in the comparative psychology of the vertebrates, -and which should be the empirical starting-point of all scientific -human psychology, is the characteristic structure of the central -nervous system. This central psychic organ has a particular position, -shape, and texture in the vertebrate as it has in all the higher -species. In every case we find a spinal medulla, a strong cylindrical -nervous cord, which runs down the middle of the back, in the upper -part of the vertebral column (or the cord which represents it). In -every case a number of nerves branch off from this medulla in regular -division, one pair to each segment or vertebra. In every case this -medullary cord arises in the same way in the foetus; a fine groove -appears in the middle axis of the skin at the back; then the parallel -borders of this medullary groove are lifted up a little, bend over -towards each other, and form into a kind of tube. - -The long dorsal cylindrical medullary tube which is thus formed is -thoroughly characteristic of the vertebrates; it is always the same in -the early embryonic sketch of the organism, and it is always the chief -feature of the different kinds of psychic organ which evolve from it in -time. Only one single group of invertebrates has a similar structure: -the rare, marine _tunicata_, copelata, ascidia, and thalidiæ. These -animals have other important peculiarities of structure (especially -in the chorda and the gut) which show a striking divergence from -the other invertebrates and resemblance to the vertebrates. The -inference we draw is that both these groups, the vertebrates and the -tunicates, have arisen from a common ancestral group of the vermalia, -the _prochordonia_.[21] Still, there is a great difference between -the two classes in the fact that the body of the tunicate does not -articulate, or form members, and has a very simple organization (most -of them subsequently attach themselves to the bottom of the sea and -degenerate). The vertebrate, on the other hand, is characterized -by an early development of internal members, and the formation of -pro-vertebræ (_vertebratio_). This prepares the way for the much higher -development of their organism, which finally attains perfection in man. -This is easily seen in the finer structure of his spinal cord, and in -the development of a number of segmental pairs of nerves, the spinal -nerves, which proceed to the various parts of the body. - -The long ancestral history of our "vertebrate soul" commences with the -formation of the most rudimentary spinal cord in the earliest acrania; -slowly and gradually, through a period of many millions of years, it -conducts to that marvellous structure of the human brain which seems -to entitle the highest primate form to quite an exceptional position -in nature. Since a clear conception of this slow and steady progress -of our phyletic psychogeny is indispensable for a true psychology, we -must divide that vast period into a number of stages or sections: in -each of them the perfecting of the structure of the nervous centre has -been accompanied by a corresponding evolution of its function, the -_psyche_. I distinguish eight of these periods in the phylogeny of -the spinal cord, which are characterized by eight different groups of -vertebrates: (1) the acrania; (2) the cyclostomata; (3) the fishes; (4) -the amphibia; (5) the implacental mammals (monotremes and marsupials); -(6) the earlier placental mammals, especially the prosimiæ; (7) the -younger primates, the simiæ; and (8) the anthropoid apes and man. - -I. First stage--the _acrania_: their only modern representative is the -lancelot or amphioxus; the psychic organ remains a simple medullary -tube, and contains a regularly segmented spinal cord, without brain. - -II. Second stage--the _cyclostomata_: the oldest group of the craniota, -now only represented by the _petromyzontes_ and _myxinoides_: -the fore-termination of the cord expands into a vesicle, which -then subdivides into five successive parts--the great-brain, -intermediate-brain, middle-brain, little-brain, and hind-brain: these -five cerebral vesicles form the common type from which the brain of all -craniota has evolved, from the lamprey to man. - -III. Third stage--the _primitive fishes_ (_selachii_): similar to the -modern shark: in these oldest fishes, from which all the gnathostomata -descend, the more pronounced division of the five cerebral vesicles -sets in. - -IV. Fourth stage--the _amphibia_. These earliest land animals, making -their first appearance in the Carboniferous period, represent the -commencement of the characteristic structure of the _tetrapod_ and -a corresponding development of the fish-brain: it advances still -further in their Permian successors, the _reptiles_, the earliest -representatives of which, the _tocosauria_, are the common ancestors of -all the amniota (reptiles and birds on one side, mammals on the other). - -V.-VIII. Fifth to the eighth stages--the _mammals_. I have exhaustively -treated, and illustrated with a number of plates, in my _Anthropogeny_, -the evolution of our nervous system and the correlative question of the -development of the soul. I have now, therefore, merely to refer the -reader to that work. It only remains for me to add a few remarks on the -last and most interesting class of facts pertaining to this--to the -evolution of the soul and its organs within the limits of the class -mammalia. In doing so, I must remind the reader that the _monophyletic -origin_ of this class--that is, the descent of all the mammals from -one common ancestral form (of the Triassic period)--is now fully -established. - -The most important consequence of the monophyletic origin of the -mammals is the necessity of deriving the human soul from a long -evolutionary series of other mammal souls. A deep anatomical and -physiological gulf separated the brain structure and the dependent -psychic activity of the higher mammals from those of the lower: -this gulf, however, is completely bridged over by a long series of -intermediate stages. The period of at least fourteen (more than a -hundred, on other estimates) million years, which has elapsed since the -commencement of the Triassic period, is amply sufficient to allow even -the greatest psychological advance. The following is a summary of the -results of investigation in this quarter, which has recently been very -penetrating: - -I. The brain of the mammal is differentiated from that of the other -vertebrates by certain features, which are found in all branches of the -class; especially by a preponderant development of the first and fourth -vesicles, the cerebrum and cerebellum, while the third vesicle, the -middle brain, disappears altogether. - -II. The brain development of the lowest and earliest mammals (the -monotremes, marsupials, and prochoriates) is closely allied to -that of their palæozoic ancestors, the Carboniferous amphibia (the -_stegocephala_) and the Permian reptiles (the _tocosauria_). - -III. During the Tertiary period commences the typical development of -the cerebrum, which distinguishes the younger mammals so strikingly -from the older. - -IV. The special development (quantitatively and qualitatively) of -the cerebrum which is so prominent a feature in man, and which is the -root of his pre-eminent psychic achievements, is only found, outside -humanity, in a small section of the most highly developed mammals of -the earlier Tertiary epoch, especially in the anthropoid apes. - -V. The differences of brain structure and psychic faculty which -separate man from the anthropoid ape are slighter than the corresponding -interval between the anthropoid apes and the lower primates (the -earliest simiæ and prosimiæ). - -VI. Consequently, the historical, gradual evolution of the human soul -from a long chain of higher and lower mammal souls must, by application -of the universally valid phyletic laws of the theory of descent, be -regarded as a _fact_ which has been scientifically proved. - - - - -CHAPTER X - -CONSCIOUSNESS - - Consciousness as a Natural Phenomenon--Its Definition--Difficulties - of the Problem--Its Relation to the Life of the Soul--Our - Human Consciousness--Various Theories: I. Anthropistic - Theory (Descartes); II. Neurological Theory (Darwin); - III. Animal Theory (Schopenhauer); IV. Biological Theory - (Fechner); V. Cellular Theory (Fritz Schultze); VI. Atomistic - Theory--Monistic and Dualistic Theories--Transcendental - Character of Consciousness--The Ignorabimus Verdict of Du - Bois-Reymond--Physiology of Consciousness--Discovery of the - Organs of Thought by Flechsig--Pathology--Double and Intermittent - Consciousness--Ontogeny of Consciousness: Modifications at - Different Ages--Phylogeny of Consciousness--Formation of Concepts - - -No phenomenon of the life of the soul is so wonderful and so variously -interpreted as consciousness. The most contradictory views are current -to-day, as they were two thousand years ago, not only with regard to -the nature of this psychic function and its relation to the body, -but even as to its diffusion in the organic world and its origin and -development. It is more responsible than any other psychic faculty for -the erroneous idea of an "immaterial soul" and the belief in "personal -immortality"; many of the gravest errors that still dominate even -our modern civilization may be traced to it. Hence it is that I have -entitled consciousness "the central mystery of psychology"; it is -the strong citadel of all mystic and dualistic errors, before whose -ramparts the best-equipped efforts of reason threaten to miscarry. This -fact would suffice of itself to induce us to make a special critical -study of consciousness from our monistic point of view. We shall see -that consciousness is simply a natural phenomenon like any other -psychic quality, and that it is subject to the law of substance like -all other natural phenomena. - -Even as to the elementary idea of consciousness, its contents and -extension, the views of the most distinguished philosophers and -scientists are widely divergent. Perhaps the meaning of consciousness -is best conceived as an _internal perception_, and compared with the -action of _a mirror_. As its two chief departments we distinguish -objective and subjective consciousness--consciousness of the world, -the non-ego, and of the ego. By far the greater part of our conscious -activity, as Schopenhauer justly remarked, belongs to the consciousness -of the outer world, or the non-ego: this _world-consciousness_ -embraces all possible phenomena of the outer world which are in any -sense accessible to our minds. Much more contracted is the sphere -of _self-consciousness_, the internal mirror of all our own psychic -activity, all our presentations, sensations, and volitions. - -Many distinguished thinkers, especially on the physiological side -(Wundt and Ziehen, for instance) take the ideas of consciousness and -psychic function to be identical--"all psychic action is conscious"; -the province of psychic life, they say, is coextensive with that -of consciousness. In our opinion, such a definition gives an undue -extension to the meaning of consciousness, and occasions many -errors and misunderstandings. We share, rather, the view of other -philosophers (Romanes, Fritz Schultze, and Paulsen), that even our -unconscious presentations, sensations, and volitions pertain to our -psychic life; indeed, the province of these unconscious psychic actions -(reflex action, and so forth) is far more extensive than that of -consciousness. Moreover, the two provinces are intimately connected, -and are separated by no sharp line of demarcation. An unconscious -presentation may become conscious at any moment; let our attention be -withdrawn from it by some other object, and forthwith it disappears -from consciousness once more. - -The only source of our knowledge of consciousness is that faculty -itself; that is the chief cause of the extraordinary difficulty of -subjecting it to scientific research. Subject and object are one and -the same in it: the perceptive subject mirrors itself in its own -inner nature, which is to be the object of our inquiry. Thus we can -never have a complete objective certainty of the consciousness of -others; we can only proceed by a comparison of their psychic condition -with our own. As long as this comparison is restricted to _normal_ -people we are justified in drawing certain conclusions as to their -consciousness, the validity of which is unchallenged. But when we pass -on to consider _abnormal_ individuals (the genius, the eccentric, the -stupid, or the insane) our conclusions from analogy are either unsafe -or entirely erroneous. The same must be said with even greater truth -when we attempt to compare human consciousness with that of the animals -(even the higher, but especially the lower). In that case such grave -difficulties arise that the views of physiologists and philosophers -diverge as widely as the poles on the subject. We shall briefly -enumerate the most important of these views. - -I. _The anthropistic theory of consciousness._--It is peculiar to man. -To Descartes we must trace the widespread notion that consciousness -and thought are man's exclusive prerogative, and that he alone is -blessed with an "immortal soul." This famous French philosopher and -mathematician (educated in a Jesuit College) established a rigid -partition between the psychic activity of man and that of the brute. -In his opinion the human soul, a thinking, immaterial being, is -completely separated from the body, which is extended and material. -Yet it is united to the body at a certain point in the brain (the -_glandula pinealis_) for the purpose of receiving impressions from the -outer world and effecting muscular movements. The animals, not being -endowed with thought, have no soul: they are mere automata, or cleverly -constructed machines, whose sensations, presentations, and volitions -are purely mechanical, and take place according to the ordinary laws -of physics. Hence Descartes was a _dualist_ in human psychology, and -a _monist_ in the psychology of the brute. This open contradiction in -so clear and acute a thinker is very striking; in explaining it, it -is not unnatural to suppose that he concealed his real opinion, and -left the discovery of it to independent scholars. As a pupil of the -Jesuits, Descartes had been taught to deny the truth in the face of his -better insight; and perhaps he dreaded the power and the fires of the -Church. Besides, his sceptical principle, that every sincere effort to -attain the truth must start with a doubt of the traditional dogma had -already drawn upon him fanatical accusations of scepticism and atheism. -The great influence which Descartes had on subsequent philosophy was -very remarkable, and entirely in harmony with his "book-keeping by -double entry." The _materialists_ of the seventeenth and eighteenth -centuries appealed to the Cartesian theory of the animal soul and its -purely mechanical activity in support of their monistic psychology. The -_spiritualists_, on the other hand, asserted that their dogma of the -immortality of the soul and its independence of the body was firmly -established by Descartes' theory of the human soul. This view is still -prevalent in the camp of the theologians and dualistic metaphysicians. -The scientific conception of nature, however, which has been built up -in the nineteenth century, has, with the aid of empirical progress, in -physiological and comparative psychology, completely falsified it. - -II. _Neurological theory of consciousness._--It is present only -in man and those higher animals which have a centralized nervous -system and organs of sense. The conviction that a large number of -animals--at least the higher mammals--are not less endowed than man -with a thinking soul and consciousness prevails in modern zoology, -exact physiology, and the monistic psychology. The immense progress we -have made in the various branches of biology has contributed to bring -about a recognition of this important truth. We confine ourselves for -the present to the higher vertebrates, and especially the mammals. -That these most intelligent specimens of these highly developed -vertebrates--apes and dogs, in particular--have a strong resemblance to -man in their whole psychic life has been recognized and speculated on -for thousands of years. Their faculty of presentation and sensation, -of feeling and desire, is so like that of man that we need adduce no -proof of our thesis. But even the higher associational activity of -the brain, the formation of judgments and their connection into chains -of reasoning, thought, and consciousness in the narrower sense, are -developed in them after the same fashion as in man: they differ only in -degree, not in kind. Moreover, we learn from comparative anatomy and -histology that the intricate structure of the brain (both in general -and in detail) is substantially the same in the mammals as it is in -man. The same lesson is enforced by comparative ontogeny with regard -to the origin of these psychic organs. Comparative physiology teaches -us that the various states of consciousness are just the same in these -highest placentals as in man; and we learn by experiment that there -is the same reaction to external stimuli. The higher animals can be -narcotized by alcohol, chloroform, ether, etc., and may be hypnotized -by the usual methods, just as in the case of man. - -It is, however, impossible to determine mathematically at what stage -of animal life consciousness is to be first recognized as such. Some -zoologists draw the line very high in the scale, others very low. -Darwin, who most accurately distinguishes the various stages of -consciousness, intelligence, and emotion in the higher animals, and -explains them by progressive evolution, points out how difficult, -or even impossible, it is to determine the first beginning of this -supreme psychic faculty in the lower animals. Personally, out of the -many contradictory theories, I take that to be most probable which -holds _the centralization of the nervous system_ to be a condition of -consciousness; and that is wanting in the lower classes of animals. The -presence of a central nervous organ, of highly developed sense-organs, -and an elaborate association of groups of presentations, seem to me to -be required before the unity of consciousness is possible. - -III. _Animal theory of consciousness._--All animals, and they alone, -have consciousness. This theory would draw a sharp distinction between -the psychic life of the animal and of the plant. Such a distinction -was urged by many of the older writers, and was clearly formulated -by Linné in his celebrated _Systema Naturae_; the two great kingdoms -of the organic world are, in his opinion, divided by the fact that -animals have sensation and consciousness, and the plants are devoid -of them. Later on Schopenhauer laid stress on the same distinction: -"Consciousness is only known to us as a feature of animal nature. -Even though it extend upwards through the whole animal kingdom, even -to man and his reason, the unconsciousness of the plant, from which -it started, remains as the basic feature. In the lowest animals we -have but the dawn of it." The inaccuracy of this view was obvious by -about the middle of the present century, when a deeper study was made -of the psychic activity of the lower animal forms, especially the -coelenterates (sponges and cnidaria): they are undoubtedly animals, -yet there is no more trace of a definite consciousness in them than in -most of the plants. The distinction between the two kingdoms was still -further obliterated when more careful research was made into their -unicellular forms. There is no psychological difference between the -plasmophagous protozoa and the plasmodomous protophyta, even in respect -of their consciousness. - -IV. _Biological theory of consciousness._--It is found in all -organisms, animal or vegetal, but not in lifeless bodies (such as -crystals). This opinion is usually associated with the idea that all -organisms (as distinguished from inorganic substances) have souls: -the three ideas--life, soul, and consciousness--are then taken to be -coextensive. Another modification of this view holds that, though -these fundamental phenomena of organic life are inseparably connected, -yet consciousness is only a part of the activity of the soul, and of -the vital activity. Fechner, in particular, has endeavored to prove -that the plant has a "soul," in the same sense as an animal is said -to have one; and many credit the vegetal soul with a consciousness -similar to that of the animal soul. In truth, the remarkable stimulated -movements of the leaves of the sensitive plants (the mimosa, drosera, -and dionæa), the automatic movements of other plants (the clover -and wood-sorrel, and especially the hedysarum), the movements of -the "sleeping plants" (particularly the _papilionacea_), etc., are -strikingly similar to the movements of the lower animal forms: whoever -ascribes consciousness to the latter cannot refuse it to such vegetal -forms. - -V. _Cellular theory of consciousness._--It is a vital property of every -cell. The application of the cellular theory to every branch of biology -involved its extension to psychology. Just as we take the living cell -to be the "elementary organism" in anatomy and physiology, and derive -the whole system of the multicellular animal or plant from it, so, with -equal right, we may consider the "cell-soul" to be the psychological -unit, and the complex psychic activity of the higher organism to be -the result of the combination of the psychic activity of the cells -which compose it. I gave the outlines of this _cellular psychology_ -in my _General Morphology_ in 1866, and entered more fully into the -subject in my paper on "Cell-Souls and Soul-Cells." I was led to a -deeper study of this "elementary psychology" by my protracted research -into the unicellular forms of life. Many of these tiny (generally -microscopic) protists show similar expressions of sensation and will, -and similar instincts and movements, to those of higher animals; that -is especially true of the very sensitive and lively infusoria. In the -relation of these sensitive cell-organisms to their environment, and in -many other of their vital expressions (for instance, in the wonderful -architecture of the rhizopods, the thalamophoræ, and the infusoria), -we seemed to have clear indications of conscious psychic action. If, -then, we accept the biological theory of consciousness (No. IV.), and -credit every psychic function with a share of that faculty, we shall be -compelled to ascribe it to each independent protist cell. In that case -its material basis would be either the entire protoplasm of the cell, -or its nucleus, or a portion of it. In the "psychade theory" of Fritz -Schultze the elementary consciousness of the _psychade_ would have -the same relation to the individual cells as personal consciousness -has to the multicellular organism of the personality in the higher -animals and man. It is impossible definitively to disprove this theory, -which I held at one time. Still, I now feel compelled to agree with -Max Verworn, in his belief that none of the protists have a developed -self-consciousness, but that their sensations and movements are of an -unconscious character. - -VI. _Atomistic theory of consciousness._--It is an elementary property -of all atoms. This atomistic hypothesis goes furthest of all the -different views as to the extension of consciousness. It certainly -escapes the difficulty which so many philosophers and biologists -experience in solving the problem of the first origin of consciousness. -It is a phenomenon of so peculiar a character that a derivation of -it from other psychic functions seems extremely hazardous. It seemed, -therefore, the easiest way out of the difficulty to conceive it as an -inherent property of all matter, like gravitation or chemical affinity. -On that hypothesis there would be as many forms of this original -consciousness as there are chemical elements; each atom of hydrogen -would have its hydrogenic consciousness, each atom of carbon its -carbonic consciousness, and so forth. There are philosophers, even, who -ascribe consciousness to the four elements of Empedocles, the union of -which, by "love and hate," produces the totality of things. - -Personally, I have never subscribed to this hypothesis of atomic -consciousness. I emphasize the point because Emil du Bois-Reymond -has attributed it to me. In the controversy I had with him (1880) he -violently attacked my "pernicious and false philosophy," and contended -that I had, in my paper on "The Perigenesis of the Plastidule," "laid -it down as a metaphysical axiom that every atom has its individual -consciousness." On the contrary, I explicitly stated that I conceive -the elementary psychic qualities of sensation and will, which may -be attributed to atoms, to be _unconscious_--just as unconscious as -the elementary memory which I, in company with that distinguished -physiologist, Ewald Hering, consider to be "a common function of -all organized matter"--or, more correctly, "living substance." Du -Bois-Reymond curiously confuses "soul" and "consciousness"; whether -from oversight or not I cannot say. Since he considers consciousness -to be a transcendental phenomenon (as we shall see presently), while -denying that character to other psychic functions--the action of the -senses, for example--I must infer that he recognizes the difference -of the two ideas. Other parts of his eloquent speeches contain quite -the opposite view, for the famous orator not infrequently contradicts -himself on important questions of principle. However, I repeat that, in -my opinion, consciousness is only _part_ of the psychic phenomena which -we find in man and the higher animals; the great majority of them are -unconscious. - -However divergent are the different views as to the nature and -origin of consciousness, they may, nevertheless, on a clear and -logical examination, all be reduced to two fundamental theories--the -transcendental (or dualistic) and the physiological (or monistic). -I have myself always held the latter view, in the light of my -evolutionary principles, and it is now shared by a great number of -distinguished scientists, though it is by no means generally accepted. -The transcendental theory is the older and much more common; it -has recently come once more into prominence, principally through -Du Bois-Reymond, and it has acquired a great importance in modern -discussions of cosmic problems through his famous "Ignorabimus speech." -On account of the extreme importance of this fundamental question we -must touch briefly on its main features. - -In the celebrated discourse on "The Limits of Natural Science," -which E. du Bois-Reymond gave on August 14, 1872, at the Scientific -Congress at Leipzig, he spoke of two "absolute limits" to our possible -knowledge of nature which the human mind will never transcend in its -most advanced science--_never_, as the oft-quoted termination of the -address, "Ignorabimus," emphatically pronounces. The first absolutely -insoluble "world-enigma" is the "connection of matter and force," and -the distinctive character of these fundamental natural phenomena; we -shall go more fully into this "problem of substance" in the twelfth -chapter. The second insuperable difficulty of philosophy is given as -the problem of consciousness--the question how our mental activity -is to be explained by material conditions, especially movements, how -"substance [the substance which underlies matter and force] comes, -under certain conditions, to feel, to desire, and to think." - -For brevity, and in order to give a characteristic name to the Leipzig -discourse, I have called it the "Ignorabimus speech"; this is the -more permissible, as E. du Bois-Reymond himself, with a just pride, -eight years afterwards, speaking of the extraordinary consequences -of his discourse, said: "Criticism sounded every possible note, from -friendly praise to the severest censure, and the word 'Ignorabimus,' -which was the culmination of my inquiry, was at once transformed into a -kind of scientific shibboleth." It is quite true that loud praise and -approbation resounded in the halls of the dualistic and spiritualistic -philosophy, and especially in the camp of the "Church militant"; even -the spiritists and the host of believers, who thought the immortality -of their precious souls was saved by the "Ignorabimus," joined in the -chorus. The "severest censure" came at first only from a few scientists -and philosophers--from the few who had sufficient scientific knowledge -and moral courage to oppose the dogmatism of the all-powerful secretary -and dictator of the Berlin Academy of Science. - -Towards the end, however, the author of the "Ignorabimus speech" briefly -alluded to the question whether these two great "world-enigmas," the -general problem of substance and the special problem of consciousness, -are not two aspects of one and the same problem. "This idea," he said, -"is certainly the simplest, and preferable to the one which makes the -world doubly incomprehensible. Such, however, is the nature of things -that even here we can obtain no clear knowledge, and it is useless to -speak further of the question." The latter sentiment I have always -stoutly contested, and have endeavored to prove that the two great -questions are not two distinct problems. "The neurological problem -of consciousness is but a particular aspect of the all-pervading -cosmological problem of substance." - -The peculiar phenomenon of consciousness is not, as Du Bois-Reymond -and the dualistic school would have us believe, a completely -"transcendental" problem; it is, as I showed thirty-three years ago, -a _physiological_ problem, and, as such, must be reduced to the -phenomena of physics and chemistry. I subsequently gave it the more -definite title of a _neurological_ problem, as I share the view that -true consciousness (thought and reason) is only present in those higher -animals which have a centralized nervous system and organs of sense -of a certain degree of development. Those conditions are certainly -found in the higher vertebrates, especially in the placental mammals, -the class from which man has sprung. The consciousness of the highest -apes, dogs, elephants, etc., differs from that of man in degree only, -not in kind, and the graduated interval between the consciousness of -these "rational" placentals and that of the lowest races of men (the -Veddahs, etc.) is less than the corresponding interval between these -uncivilized races and the highest specimens of thoughtful humanity -(Spinoza, Goethe, Lamarck, Darwin, etc.). Consciousness is but a part -of the higher activity of the soul, and as such it is dependent on the -normal structure of the corresponding psychic organ, the brain. - -Physiological observation and experiment determined twenty years ago -that the particular portion of the mammal-brain which we call the -_seat_ (preferably the _organ_) of consciousness is a part of the -cerebrum, an area in the late-developed gray bed, or cortex, which -is evolved out of the convex dorsal portion of the primary cerebral -vesicle, the "fore-brain." Now, the morphological proof of this -physiological thesis has been successfully given by the remarkable -progress of the microscopic anatomy of the brain, which we owe to the -perfect methods of research of modern science (Kölliker, Flechsig, -Golgi, Edinger, Weigert, and others). - -The most important development is the discovery of the _organs of -thought_ by Paul Flechsig, of Leipzig; he proved that in the gray bed -of the brain are found the four seats of the central sense-organs, -or four "inner spheres of sensation"--the sphere of touch in the -vertical lobe, the sphere of smell in the frontal lobe, the sphere -of sight in the occipital lobe, and the sphere of hearing in the -temporal lobe. Between these four "sense-centres" lie the four great -"thought-centres," or centres of association, the _real organs of -mental life_; they are those highest instruments of psychic activity -that produce thought and consciousness. In front we have the frontal -brain or centre of association; behind, on top there is the vertical -brain, or parietal centre of association, and underneath the principal -brain, or "the great occipito-temporal centre of association" (the -most important of all); lower down, and internally, the insular brain -or the insula of Reil, the insular centre of association. These four -"thought-centres," distinguished from the intermediate "sense-centres" -by a peculiar and elaborate nerve-structure, are the true and sole -organs of thought and consciousness. Flechsig has recently pointed out -that, in the case of man, very specific structures are found in one -part of them; these structures are wanting in the other mammals, and -they, therefore, afford an explanation of the superiority of man's -mental powers. - -The momentous announcement of modern physiology, that the cerebrum is -the organ of consciousness and mental action in man and the higher -mammals, is illustrated and confirmed by the pathological study of -its diseases. When parts of the cortex are destroyed by disease their -respective functions are affected, and thus we are enabled, to some -extent, to localize the activities of the brain; when certain parts -of the area are diseased, that portion of thought and consciousness -disappears which depends on those particular sections. Pathological -experiment yields the same result; the decay of some known area (for -instance, the centre of speech) extinguishes its function (speech). -In fact, there is proof enough in the most familiar phenomena of -consciousness of their complete dependence on chemical changes in -the substance of the brain. Many beverages (such as coffee and -tea) stimulate our powers of thought; others (such as wine and -beer) intensify feeling; musk and camphor reanimate the fainting -consciousness; ether and chloroform deaden it, and so forth. How -would that be possible if consciousness were an immaterial entity, -independent of these anatomical organs? And what becomes of the -consciousness of the "immortal soul" when it no longer has the use of -these organs? - -These and other familiar facts prove that man's consciousness--and -that of the nearest mammals--is _changeable_, and that its activity -is always open to modification from inner (alimentation, circulation, -etc.) and outer causes (lesion of the brain, stimulation, etc.). -Very instructive, too, are the facts of double and intermittent -consciousness, which remind us of "alternate generations of -presentations." The same individual has an entirely different -consciousness on different days, with a change of circumstances; he -does not know to-day what he did yesterday: yesterday he could say, "I -am I"; to-day he must say, "I am another being." Such intermittence of -consciousness may last not only days, but months, and even years; the -change may even become permanent. - -As everybody knows, the new-born infant has no consciousness. Preyer -has shown that it is only developed after the child has begun to -speak; for a long time it speaks of itself in the third person. -In the important moment when it first pronounces the word "I," -when the feeling of self becomes clear, we have the beginning of -self-consciousness, and of the antithesis to the non-ego. The rapid -and solid progress in knowledge which the child makes in its first -ten years, under the care of parents and teachers, and the slower -progress of the second decade, until it reaches complete maturity of -mind, are intimately connected with a great advancement in the growth -and development of consciousness and of its organ, the brain. But even -when the pupil has got his "certificate of maturity" his consciousness -is still far from mature; it is then that his "world-consciousness" -first begins to develop, in his manifold relations with the outer -world. Then, in the third decade, we have the full maturity of rational -thought and consciousness, which, in cases of normal development, yield -their ripe fruits during the next three decades. The slow, gradual -degeneration of the higher mental powers, which characterizes senility, -usually sets in at the commencement of the seventh decade--sometimes -earlier, sometimes later. Memory, receptiveness, and interest in -particular objects gradually decay; though productivity, mature -consciousness, and philosophic interest in general truths often remain -for many years longer. - -The individual development of consciousness in earlier youth proves the -universal validity of the _biogenetic law_; and, indeed, it is still -recognizable in many ways during the later years. In any case, the -ontogenesis of consciousness makes it perfectly clear that it is not -an "immaterial entity," but a physiological function of the brain, and -that it is, consequently, no exception to the general law of substance. - -From the fact that consciousness, like all other psychic functions, -is dependent on the normal development of certain organs, and that -it gradually unfolds in the child in proportion to the development -of those organs, we may already conclude that it has arisen in the -animal kingdom by a gradual historical development. Still, however -certain we are of the fact of this natural evolution of consciousness, -we are, unfortunately, not yet in a position to enter more deeply -into the question and construct special hypotheses in elucidation -of it. Palæontology, it is true, gives us a few facts which are not -without significance. For instance, the quantitative and qualitative -development of the brain of the placental mammals during the Tertiary -period is very remarkable. The cavity of many of the fossil skulls of -the period has been carefully examined, and has given us a good deal of -reliable information as to the size, and, to some extent, as to the -structure, of the brain they enclosed. We find, within the limits of -one and the same group (the ungulates, the rodents, or the primates), a -marked advance in the later miocene and pliocene specimens as compared -with the earlier eocene and oligocene representatives of the same stem; -in the former the brain (in proportion to the size of the organism) is -six to eight times as large as in the latter. - -Moreover, that highest stage of consciousness, which is reached by man -alone, has been evolved step by step--even by the very progress of -civilization--from a lower condition, as we find illustrated to-day in -the case of uncivilized races. That is easily proved by a comparison -of their languages, which is closely connected with the comparison of -their ideas. The higher the conceptual faculty advances in thoughtful -civilized man, the more qualified he is to detect common features amid -a multitude of details, and embody them in general concepts, and so -much the clearer and deeper does his consciousness become. - - - - -CHAPTER XI - -THE IMMORTALITY OF THE SOUL - - The Citadel of Superstition--Athanatism and Thanatism--Individual - Character of Death--Immortality of the Unicellular Organisms - (Protists)--Cosmic and Personal Immortality--Primary Thanatism (of - Uncivilized Peoples)--Secondary Thanatism (of Ancient and Recent - Philosophers)--Athanatism and Religion--Origin of the Belief - in Immortality--Christian Athanatism--Eternal Life--The Day of - Judgment--Metaphysical Athanatism--Substance of the Soul--Ether - Souls and Air Souls; Fluid Souls and Solid Souls--Immortality of - the Animal Soul--Arguments for and Against Athanatism--Athanatist - Illusions - - -When we turn from the genetic study of the soul to the great question -of its immortality, we come to that highest point of superstition which -is regarded as the impregnable citadel of all mystical and dualistic -notions. For in this crucial question, more than in any other problem, -philosophic thought is complicated by the selfish interest of the human -personality, who is determined to have a guarantee of his existence -beyond the grave at any price. This "higher necessity of feeling" is -so powerful that it sweeps aside all the logical arguments of critical -reason. Consciously or unconsciously, most men are influenced in all -their general views, and, therefore, in their theory of life, by the -dogma of personal immortality; and to this theoretical error must be -added practical consequences of the most far-reaching character. It is -our task, therefore, to submit every aspect of this important dogma to -a critical examination, and to prove its untenability in the light of -the empirical data of modern biology. - -In order to have a short and convenient expression for the two opposed -opinions on the question, we shall call the belief in man's personal -immortality "athanatism" (from _athanes_ or _athanatos_ == immortal). -On the other hand, we give the name of "thanatism" (from _thanatos_ -== death) to the opinion which holds that at a man's death not only -all the other physiological functions are arrested, but his "soul" -also disappears--that is, that sum of cerebral functions which psychic -dualism regards as a peculiar entity, independent of the other vital -processes in the living body. - -In approaching this physiological problem of death we must point out -the _individual_ character of this organic phenomenon. By death we -understand simply the definitive cessation of the vital activity of -the _individual_ organism, no matter to which category or stage of -individuality the organism in question belongs. Man is dead when his -own personality ceases to exist, whether he has left offspring that -they may continue to propagate for many generations or not. In a -certain sense we often say that the minds of great men (in a dynasty -of eminent rulers, for instance, or a family of talented artists) live -for many generations; and in the same way we speak of the "soul" of -a noble woman living in her children and children's children. But in -these cases we are dealing with intricate phenomena of _heredity_, -in which a microscopic cell (the sperm-cell of the father or the -egg-cell of the mother) transmits certain features to offspring. The -particular personalities who produce those sexual cells in thousands -are mortal beings, and at their death their personal psychic activity -is extinguished like every other physiological function. - -A number of eminent zoologists--Weismann being particularly -prominent--have recently defended the opinion that only the lowest -unicellular organisms, the protists, are immortal, in contradistinction -to the multicellular plants and animals, whose bodies are formed of -tissues. This curious theory is especially based on the fact that -most of the protists multiply without sexual means, by division or -the formation of spores. In such processes the whole body of the -unicellular organism breaks up into two or more equal parts (daughter -cells), and each of these portions completes itself by further growth -until it has the size and form of the mother cell. However, by the very -process of division the _individuality_ of the unicellular creature -has been destroyed; both its physiological and its morphological unity -have gone. The view of Weismann is logically inconsistent with the -very notion of _individual_--an "indivisible" entity; for it implies -a unity which cannot be divided without destroying its nature. In -this sense the unicellular protophyta and protozoa are throughout -life _physiological individuals_, just as much as the multicellular -tissue-plants and animals. A sexual propagation by simple division -is found in many of the multicellular species (for instance, in many -cnidaria, corals, medusæ, etc.); the mother animal, the division of -which gives birth to the two daughter animals, ceases to exist with -the segmentation. "The protozoa," says Weismann, "have no individuals -and no generations in the metazoic sense." I must entirely dissent -from his thesis. As I was the first to introduce the title of -_metazoa_, and oppose these multicellular, tissue-forming animals to -the unicellular _protozoa_ (infusoria, rhizopods, etc.), and as I was -the first to point out the essential difference in the development of -the two (the former from germinal layers, and the latter not), I must -protest that I consider the _protozoa_ to be just as mortal in the -physiological (and psychological) sense as the _metazoa_; neither body -nor soul is immortal in either group. The other erroneous consequences -of Weismann's notion have been refuted by Moebius (1884), who justly -remarks that "every event in the world is periodic," and that "there is -no source from which immortal organic individuals might have sprung." - -When we take the idea of immortality in the widest sense, and extend -it to the totality of the knowable universe, it has a scientific -significance; it is then not merely acceptable, but self-evident, -to the monistic philosopher. In that sense the thesis of the -indestructibility and eternal duration of all that exists is equivalent -to our supreme law of nature, the _law of substance_ (see chap. xii). -As we intend to discuss this immortality of the cosmos fully later on, -in establishing the theory of the persistence of matter and force, -we shall not dilate on it at present. We pass on immediately to the -criticism of that belief in immortality which is the only sense usually -attached to the word, the immortality of the individual soul. We -shall first inquire into the extent and the origin of this mystic and -dualistic notion, and point out, in particular, the wide acceptance -of the contradictory thesis, our monistic, empirically established -_thanatism_. I must distinguish two essentially different forms of -thanatism--primary and secondary; primary thanatism is the original -absence of the dogma of immortality (in the primitive uncivilized -races); secondary thanatism is the later outcome of a rational -knowledge of nature in the civilized intelligence. - -We still find it asserted in philosophic, and especially in theological, -works that belief in the personal immortality of the human soul was -originally shared by all men--or, at least, by all "rational" men. That -is not the case. This dogma is not an original idea of the human mind, -nor has it ever found universal acceptance. It has been absolutely -proved by modern comparative ethnology that many uncivilized races -of the earliest and most primitive stage had no notion either of -immortality or of God. That is true, for instance, of the Veddahs of -Ceylon, those primitive pygmies whom, on the authority of the able -studies of the Sarasins, we consider to be a relic of the earliest -inhabitants of India;[22] it is also the case in several of the -earliest groups of the nearly related Dravidas, the Indian Seelongs, -and some native Australian races. Similarly, several of the primitive -branches of the American race, in the interior of Brazil, on the upper -Amazon, etc., have no knowledge either of gods or immortality. This -_primary_ absence of belief in immortality and deity is an extremely -important fact; it is, obviously, easy to distinguish from the -_secondary_ absence of such belief, which has come about in the highest -civilized races as the result of laborious critico-philosophical study. - -Differently from the primary thanatism which originally characterized -primitive man, and has always been widely spread, the _secondary_ -absence of belief in immortality is only found at a late stage of -history: it is the ripe fruit of profound reflection on life and death, -the outcome of bold and independent philosophical speculation. We first -meet it in some of the Ionic philosophers of the sixth century B.C., -then in the founders of the old materialistic philosophy, Democritus -and Empedocles, and also in Simonides and Epicurus, Seneca and Plinius, -and in an elaborate form in Lucretius Carus. With the spread of -Christianity at the decay of classical antiquity, athanatism, one of -its chief articles of faith, dominated the world, and so, amid other -forms of superstition, the myth of personal immortality came to be -invested with a high importance. - -Naturally, through the long night of the Dark Ages it was rarely that -a brave free-thinker ventured to express an opinion to the contrary: -the examples of Galileo, Giordano Bruno, and other independent -philosophers, effectually destroyed all freedom of utterance. Heresy -only became possible when the Reformation and the Renaissance had -broken the power of the papacy. The history of modern philosophy tells -of the manifold methods by which the matured mind of man sought to -rid itself of the superstition of immortality. Still, the intimate -connection of the belief with the Christian dogma invested it with -such power, even in the more emancipated sphere of Protestantism, -that the majority of convinced free-thinkers kept their sentiments to -themselves. From time to time some distinguished scholar ventured to -make a frank declaration of his belief in the impossibility of the -continued life of the soul after death. This was done in France in the -second half of the eighteenth century by Voltaire, Danton, Mirabeau, -and others, and by the leaders of the materialistic school of those -days, Holbach, Lamettrie, etc. The same opinion was defended by the -able friend of the Materialists, the greatest of the Hohenzollerns, the -monistic "philosopher of Sans-souci." What would Frederick the Great, -the "crowned thanatist and atheist," say, could he compare his monistic -views with those of his successor of to-day? - -Among thoughtful physicians the conviction that the existence of the -soul came to an end at death has been common for centuries: generally, -however, they refrained from giving it expression. Moreover, the -empirical science of the brain remained so imperfect during the last -century that the soul could continue to be regarded as its mysterious -inhabitant. It was the gigantic progress of biology in the present -century, and especially in the latter half of the century, that -finally destroyed the myth. The establishment of the theory of descent -and the cellular theory, the astounding discoveries of ontogeny and -experimental physiology--above all, the marvellous progress of the -microscopic anatomy of the brain, gradually deprived athanatism of -every basis; now, indeed, it is rarely that an informed and honorable -biologist is found to defend the immortality of the soul. All the -monistic philosophers of the century (Strauss, Feuerbach, Büchner, -Spencer, etc.) are thanatists. - -The dogma of personal immortality owes its great popularity and its -high importance to its intimate connection with the teaching of -Christianity. This circumstance gave rise to the erroneous and still -prevalent belief that the myth is a fundamental element of all the -higher religions. That is by no means the case. The higher Oriental -religions include no belief whatever in the immortality of the soul; -it is not found in Buddhism, the religion that dominates thirty per -cent. of the entire human race; it is not found in the ancient popular -religion of the Chinese, nor in the reformed religion of Confucius -which succeeded it; and, what is still more significant, it is not -found in the earlier and purer religion of the Jews. Neither in the -"five Mosaic books," nor in any of the writings of the Old Testament -which were written before the Babylonian Exile, is there any trace of -the notion of individual persistence after death. - -The mystic notion that the human soul will live forever after death has -had a polyphyletic origin. It was unknown to the earliest speaking man -(the hypothetical _homo primigenius_ of Asia), to his predecessors, of -course, the _pithecanthropus_ and _prothylobates_, and to the least -developed of his modern successors, the Veddahs of Ceylon, the Seelongs -of India, and other distant races. With the development of reason and -deeper reflection on life and death, sleep and dreams, mystic ideas of -a dualistic composition of our nature were evolved--independently of -each other--in a number of the earlier races. Very different influences -were at work in these polyphyletic creations--worship of ancestors, -love of relatives, love of life and desire of its prolongation, hope of -better conditions of life beyond the grave, hope of the reward of good -and punishment of evil deeds, and so forth. Comparative psychology has -recently brought to our knowledge a great variety of myths and legends -of that character; they are, for the most part, closely associated -with the oldest forms of theistic and religious belief. In most of the -modern religions athanatism is intimately connected with theism; the -majority of believers transfer their materialistic idea of a "personal -God" to their "immortal soul." That is particularly true of the -dominant religion of modern civilized states, Christianity. - -As everybody knows, the dogma of the immortality of the soul has long -since assumed in the Christian religion that rigid form which it -has in the articles of faith: "I believe in the resurrection of the -body and in an eternal life." Man will arise on "the last day," as -Christ is alleged to have done on Easter morn, and receive a reward -according to the tenor of his earthly life. This typically Christian -idea is thoroughly materialistic and anthropomorphic; it is very little -superior to the corresponding crude legends of uncivilized peoples. The -impossibility of "the resurrection of the body" is clear to every man -who has some knowledge of anatomy and physiology. The resurrection of -Christ, which is celebrated every Easter by millions of Christians, is -as purely mythical as "the awakening of the dead," which he is alleged -to have taught. These mystic articles of faith are just as untenable in -the light of pure reason as the cognate hypothesis of "eternal life." - -The fantastic notions which the Christian Church disseminates as to the -eternal life of the immortal soul after the dissolution of the body are -just as materialistic as the dogma of "the resurrection of the body." -In his interesting work on _Religion in the Light of the Darwinian -Theory_, Savage justly remarks: "It is one of the standing charges of -the Church against science that it is materialistic. I must say, in -passing, that the whole ecclesiastical doctrine of a future life has -always been, and still is, materialism of the purest type. It teaches -that the material body shall rise, and dwell in a material heaven." To -prove this one has only to read impartially some of the sermons and -ornate discourses in which the glory of the future life is extolled -as the highest good of the Christian, and belief in it is laid down to -be the foundation of morality. According to them, all the joys of the -most advanced modern civilization await the pious believer in Paradise, -while the "All-loving Father" reserves his eternal fires for the -godless materialist. - -In opposition to the materialist athanatism, which is dominant in -the Christian and Mohammedan Churches, we have, apparently, a purer -and higher form of faith in the _metaphysical athanatism_, as taught -by most of our dualist and spiritualist philosophers. Plato must be -considered its chief creator: in the fourth century before Christ -he taught that complete dualism of body and soul which afterwards -became one of the most important, theoretically, and one of the most -influential, practically, of the Christian articles of faith. The -body is mortal, material, physical; the soul is immortal, immaterial, -metaphysical. They are only temporarily associated, for the course of -the individual life. As Plato postulated an eternal life before as well -as after this temporary association, he must be classed as an adherent -of "metempsychosis," or transmigration of souls; the soul existed as -such, or as an "eternal idea," before it entered into a human body. -When it quits one body it seeks such other as is most suited to its -character for its habitation. The souls of bloody tyrants pass into the -bodies of wolves and vultures, those of virtuous toilers migrate into -the bodies of bees and ants, and so forth. The childish naïvety of this -Platonic morality is obvious; on closer examination his views are found -to be absolutely incompatible with the scientific truth which we owe to -modern anatomy, physiology, histology, and ontogeny; we mention them -only because, in spite of their absurdity, they have had a profound -influence on thought and culture. On the one hand, the mysticism of the -Neo-Platonists, which penetrated into Christianity, attaches itself to -the psychology of Plato; on the other hand, it became subsequently one -of the chief supports of spiritualistic and idealistic philosophy. The -Platonic "idea" gave way in time to the notion of psychic "substance"; -this is just as incomprehensible and metaphysical, though it often -assumed a physical appearance. - -The conception of the soul as a "substance" is far from clear in many -psychologists; sometimes it is regarded as an "immaterial" entity of -a peculiar character in an abstract and idealistic sense, sometimes -in a concrete and realistic sense, and sometimes as a confused -_tertium quid_ between the two. If we adhere to the monistic idea of -substance, which we develop in chap. xii., and which takes it to be -the simplest element of our whole world-system, we find _energy_ and -_matter_ inseparably associated in it. We must, therefore, distinguish -in the "substance of the soul" the characteristic psychic _energy_ -which is all we perceive (sensation, presentation, volition, etc.), -and the psychic _matter_, which is the inseparable basis of its -activity--that is, the living protoplasm. Thus, in the higher animals -the "matter" of the soul is a part of the nervous system; in the lower -nerveless animals and plants it is a part of their multicellular -protoplasmic body; and in the unicellular protists it is a part of -their protoplasmic cell-body. In this way we are brought once more -to the psychic organs, and to an appreciation of the fact that these -material organs are indispensable for the action of the soul; but the -soul itself is _actual_--it is the sum-total of their physiological -functions. - -However, the idea of a specific "soul-substance" found in the -dualistic philosophers who admit such a thing is very different from -this. They conceive the immortal soul to be material, yet invisible, -and essentially different from the visible body which it inhabits. - -Thus _invisibility_ comes to be regarded as a most important attribute -of the soul. Some, in fact, compare the soul with ether, and regard -it, like ether, as an extremely subtle, light, and highly elastic -material, an imponderable agency, that fills the intervals between the -ponderable particles of the living organism, others compare the soul -with the wind, and so give it a gaseous nature; and it is this simile -which first found favor with primitive peoples, and led in time to the -familiar dualistic conception. When a man died, the body remained as a -lifeless corpse, but the immortal soul "flew out of it with the last -breath." - -The comparison of the human soul with physical ether as a qualitatively -similar idea has assumed a more concrete shape in recent times through -the great progress of optics and electricity (especially in the last -decade); for these sciences have taught us a good deal about the -energy of ether, and enabled us to formulate certain conclusions as -to the material character of this all-pervading agency. As I intend -to describe these important discoveries later on (in chap. xii.), I -shall do no more at present than briefly point out that they render -the notion of an "etheric soul" absolutely untenable. Such an etheric -soul--that is a psychic substance--which is similar to physical ether, -and which, like ether, passes between the ponderable elements of the -living protoplasm or the molecules of the brain, cannot possibly -account for the individual life of the soul. Neither the mystic -notions of that kind which were warmly discussed about the middle -of the century, nor the attempts of modern "Neovitalists" to put -their mystical "vital force" on a line with physical ether, call for -refutation any longer. - -Much more widespread, and still much respected, is the view which -ascribes a gaseous nature to the substance of the soul. The comparison -of human breath with the wind is a very old one; they were originally -considered to be identical, and were both given the same name. The -_anemos_ and _psyche_ of the Greeks, and the _anima_ and _spiritus_ -of the Romans, were originally all names for "a breath of wind"; they -were transferred from this to the breath of man. After a time this -"living breath" was identified with the "vital force," and finally it -came to be regarded as the soul itself, or, in a narrower sense, as its -highest manifestation, the "spirit." From that the imagination went on -to derive the mystic notion of individual "spirits"; these, also, are -still usually conceived as "aëriform beings"--though they are credited -with the physiological functions of an organism, and they have been -photographed in certain well-known spiritist circles. - -Experimental physics has succeeded, during the last decade of the -century, in reducing all gaseous bodies to a liquid--most of them, -also, to a solid--condition. Nothing more is needed than special -apparatus, which exerts a violent pressure on the gases at a very low -temperature. By this process not only the atmospheric elements, oxygen, -hydrogen, and nitrogen, but even compound gases (such as carbonic-acid -gas) and gaseous aggregates (like the atmosphere) have been changed -from gaseous to liquid form. In this way the "invisible" substances -have become "visible" to all, and in a certain sense "tangible." -With this transformation the mystic nimbus which formerly veiled -the character of the gas in popular estimation--as an invisible body -that wrought visible effects--has entirely disappeared. If, then, the -substance of the soul were really gaseous, it should be possible to -liquefy it by the application of a high pressure at a low temperature. -We could then catch the soul as it is "breathed out" at the moment of -death, condense it, and exhibit it in a bottle as "immortal fluid" -(_Fluidum animae immortale_). By a further lowering of temperature and -increase of pressure it might be possible to solidify it--to produce -"soul-snow." The experiment has not yet succeeded. - -If athanatism were true, if, indeed, the human soul were to live for -all eternity, we should have to grant the same privilege to the souls -of the higher animals, at least to those of the nearest related mammals -(apes, dogs, etc.). For man is not distinguished from them by a special -_kind_ of soul, or by any peculiar and exclusive psychic function, -but only by a higher _degree_ of psychic activity, a superior stage -of development. In particular, consciousness--the function of the -association of ideas, thought, and reason--has reached a higher level -in many men (by no means in all) than in most of the animals. Yet this -difference is far from being so great as is popularly supposed; and it -is much slighter in every respect than the corresponding difference -between the higher and the lower animal souls, or even the difference -between the highest and the lowest stages of the human soul itself. If -we ascribe "personal immortality" to man, we are bound to grant it also -to the higher animals. - -It is, therefore, quite natural that we should find this belief in -the immortality of the animal soul among many ancient and modern -peoples; we even meet it sometimes to-day in many thoughtful men -who postulate an "immortal life" for themselves, and have, at the -same time, a thorough empirical knowledge of the psychic life of the -animals. I once knew an old head-forester, who, being left a widower -and without children at an early age, had lived alone for more than -thirty years in a noble forest of East Prussia. His only companions -were one or two servants, with whom he exchanged merely a few necessary -words, and a great pack of different kinds of dogs, with which he -lived in perfect psychic communion. Through many years of training -this keen observer and friend of nature had penetrated deep into the -individual souls of his dogs, and he was as convinced of their personal -immortality as he was of his own. Some of his most intelligent dogs -were, in his impartial and objective estimation, at a higher stage of -psychic development than his old, stupid maid and the rough, wrinkled -manservant. Any unprejudiced observer, who will study the conscious -and intelligent psychic activity of a fine dog for a year, and follow -attentively the physiological processes of its thought, judgment, -and reason, will have to admit that it has just as valid a claim to -immortality as man himself. - -The proofs of the immortality of the soul, which have been adduced for -the last two thousand years, and are, indeed, still credited with some -validity, have their origin, for the most part, not in an effort to -discover the truth, but in an alleged "necessity of emotion"--that is, -in imagination and poetic conceit. As Kant puts it, the immortality of -the soul is not an object of pure reason, but a "postulate of practical -reason." But we must set "practical reason" entirely aside, together -with all the "exigencies of emotion, or of moral education, etc.," when -we enter upon an honest and impartial pursuit of truth; for we shall -only attain it by the work of pure reason, starting from empirical -data and capable of logical analysis. We have to say the same of -athanatism as of theism; both are creations of poetic mysticism and of -transcendental "faith," not of rational science. - -When we come to analyze all the different proofs that have been urged -for the immortality of the soul, we find that not a single one of them -is of a scientific character; not a single one is consistent with the -truths we have learned in the last few decades from physiological -psychology and the theory of descent. The _theological_ proof--that -a personal creator has breathed an immortal soul (generally regarded -as a portion of the divine soul) into man--is a pure myth. The -_cosmological_ proof--that the "moral order of the world" demands -the eternal duration of the human soul--is a baseless dogma. The -_teleological_ proof--that the "higher destiny" of man involves the -perfecting of his defective, earthly soul beyond the grave--rests -on a false anthropism. The _moral_ proof--that the defects and -the unsatisfied desires of earthly existence must be fulfilled by -"compensative justice" on the other side of eternity--is nothing -more than a pious wish. The _ethnological_ proof--that the belief in -immortality, like the belief in God, is an innate truth, common to -all humanity--is an error in fact. The _ontological_ proof--that the -soul, being a "simple, immaterial, and indivisible entity," cannot be -involved in the corruption of death--is based on an entirely erroneous -view of the psychic phenomena; it is a spiritualistic fallacy. All -these and similar "proofs of athanatism" are in a parlous condition; -they are definitely annulled by the scientific criticism of the last -few decades. - -The extreme importance of the subject leads us to oppose to these -untenable "proofs of immortality" a brief exposition of the sound -scientific arguments against it. The _physiological_ argument shows -that the human soul is not an independent, immaterial substance, but, -like the soul of all the higher animals, merely a collective title -for the sum-total of man's cerebral functions; and these are just -as much determined by physical and chemical processes as any of the -other vital functions, and just as amenable to the law of substance. -The _histological_ argument is based on the extremely complicated -microscopic structure of the brain; it shows us the true "elementary -organs of the soul" in the ganglionic cells. The _experimental_ -argument proves that the various functions of the soul are bound up -with certain special parts of the brain, and cannot be exercised unless -these are in a normal condition; if the areas are destroyed, their -function is extinguished; and this is especially applicable to the -"organs of thought," the four central instruments of mental activity. -The _pathological_ argument is the complement of the physiological; -when certain parts of the brain (the centres of speech, sight, -hearing, etc.) are destroyed by sickness, their activity (speech, -vision, hearing, etc.) disappears; in this way nature herself makes -the decisive physiological experiment. The _ontogenetic_ argument -puts before us the facts of the development of the soul in the -individual; we see how the child-soul gradually unfolds its various -powers; the youth presents them in full bloom, the mature man shows -their ripe fruit; in old age we see the gradual decay of the psychic -powers, corresponding to the senile degeneration of the brain. The -_phylogenetic_ argument derives its strength from palæontology, and the -comparative anatomy and physiology of the brain; co-operating with and -completing each other, these sciences prove to the hilt that the human -brain (and, consequently, its function--the soul) has been evolved step -by step from that of the mammal, and, still further back, from that of -the lower vertebrate. - -These inquiries, which might be supplemented by many other results of -modern science, prove the old dogma of the immortality of the soul -to be absolutely untenable; in the twentieth century it will not be -regarded as a subject of serious scientific research, but will be left -wholly to transcendental "faith." The "critique of pure reason" shows -this treasured faith to be a mere _superstition_, like the belief in a -personal God which generally accompanies it. Yet even to-day millions -of "believers"--not only of the lower, uneducated masses, but even of -the most cultured classes--look on this superstition as their dearest -possession and their most "priceless treasure." It is, therefore, -necessary to enter more deeply into the subject, and--assuming it to -be true--to make a critical inquiry into its practical value. It soon -becomes apparent to the impartial critic that this value rests, for -the most part, on fancy, on the want of clear judgment and consecutive -thought. It is my firm and honest conviction that a definitive -abandonment of these "athanatist illusions" would involve no painful -loss, but an inestimable positive gain for humanity. - -Man's "emotional craving" clings to the belief on immortality for two -main reasons: firstly, in the hope of better conditions of life beyond -the grave; and, secondly, in the hope of seeing once more the dear -and loved ones whom death has torn from us. As for the first hope, -it corresponds to a natural feeling of the justice of compensation, -which is quite correct subjectively, but has no objective validity -whatever. We make our claim for an indemnity for the unnumbered defects -and sorrows of our earthly existence, without the slightest real -prospect or guarantee of receiving it. We long for an eternal life in -which we shall meet no sadness and no pain, but an unbounded peace -and joy. The pictures that most men form of this blissful existence -are extremely curious; the immaterial soul is placed in the midst of -grossly material pleasures. The imagination of each believer paints -the enduring splendor according to his personal taste. The American -Indian, whose athanatism Schiller has so well depicted, trusts to -find in his Paradise the finest hunting-grounds with innumerable -hordes of buffaloes and bears; the Eskimo looks forward to sun-tipped -icebergs with an inexhaustible supply of bears, seals, and other polar -animals; the effeminate Cingalese frames his Paradise on the wonderful -island-paradise of Ceylon with its noble gardens and forests--adding -that there will be unlimited supplies of rice and curry, of cocoanuts -and other fruit, always at hand; the Mohammedan Arab believes it will -be a place of shady gardens of flowers, watered by cool springs, and -filled with lovely maidens; the Catholic fisherman of Sicily looks -forward to a daily superabundance of the most valuable fishes and the -finest macaroni, and eternal absolution for all his sins, which he -can go on committing in his eternal home; the evangelical of North -Europe longs for an immense Gothic cathedral, in which he can chant -the praises of the Lord of Hosts for all eternity. In a word, each -believer really expects his eternal life to be a direct continuation -of his individual life on earth, only in a "much improved and enlarged -edition." - -We must lay special stress on the thoroughly materialistic character -of _Christian_ athanatism, which is closely connected with the absurd -dogma of the "resurrection of the body." As thousands of paintings of -famous masters inform us, the bodies that have risen again, with the -souls that have been born again, walk about in heaven just as they did -in this vale of tears; they see God with their eyes, they hear His -voice with their ears, they sing hymns to His praise with their larynx, -and so forth. In fine, the modern inhabitants of the Christian Paradise -have the same dual character of body and soul, the same organs of an -earthly body, as our ancient ancestors had in Odin's Hall in Walhalla, -as the "immortal" Turks and Arabs have in Mohammed's lovely gardens, as -the old Greek demi-gods and heroes had in the enjoyment of nectar and -ambrosia at the table of Zeus. - -But, however gloriously we may depict this eternal life in Paradise, -it remains _endless_ in duration. Do we realize what "eternity" -means?--the uninterrupted continuance of our individual life forever! -The profound legend of the "wandering Jew," the fruitless search for -rest of the unhappy Ahasuerus, should teach us to appreciate such -an "eternal life" at its true value. The best we can desire after a -courageous life, spent in doing good according to our light, is the -eternal peace of the grave. "Lord, give them an eternal rest." - -Any impartial scholar who is acquainted with geological calculations -of time, and has reflected on the long series of millions of years the -organic history of the earth has occupied, must admit that the crude -notion of an eternal life is not a _comfort_, but a fearful _menace_, -to the best of men. Only want of clear judgment and consecutive thought -can dispute it. - -The best and most plausible ground for athanatism is found in the -hope that immortality will reunite us to the beloved friends who have -been prematurely taken from us by some grim mischance. But even this -supposed good fortune proves to be an illusion on closer inquiry; and -in any case it would be greatly marred by the prospect of meeting the -less agreeable acquaintances and the enemies who have troubled our -existence here below. Even the closest family ties would involve many -a difficulty. There are plenty of men who would gladly sacrifice all -the glories of Paradise if it meant the eternal companionship of their -"better half" and their mother-in-law. It is more than questionable -whether Henry VIII. would like the prospect of living eternally with -his six wives; or Augustus the Strong of Poland, who had a hundred -mistresses and three hundred and fifty-two children. As he was on good -terms with the Vicar of Christ, he must be assumed to be in Paradise, -in spite of his sins, and in spite of the fact that his mad military -ventures cost the lives of more than a hundred thousand Saxons. - -Another insoluble difficulty faces the athanatist when he asks _in what -stage of their individual development_ the disembodied souls will spend -their eternal life. Will the new-born infant develop its psychic powers -in heaven under the same hard conditions of the "struggle for life" -which educate man here on earth? Will the talented youth who has fallen -in the wholesale murder of war unfold his rich, unused mental powers in -Walhalla? Will the feeble, childish old man, who has filled the world -with the fame of his deeds in the ripeness of his age, live forever in -mental decay? Or will he return to an earlier stage of development? -If the immortal souls in Olympus are to live in a condition of -rejuvenescence and perfectness, then both the stimulus to the formation -of, and the interest in, personality disappear for them. - -Not less impossible, in the light of pure reason, do we find the -anthropistic myth of the "last judgment," and the separation of the -souls of men into two great groups, of which one is destined for -the eternal joys of Paradise and the other for the eternal torments -of hell--and that from a personal God who is called the "Father of -Love"! And it is this "Universal Father" who has himself created the -conditions of heredity and adaptation, in virtue of which the elect, on -the one side, were _bound_ to pursue the path towards eternal bliss, -and the luckless poor and miserable, on the other hand, were _driven_ -into the paths of the damned? - -A critical comparison of the countless and manifold fantasies which -belief in immortality has produced during the last few thousand years -in the different races and religions yields a most remarkable picture. -An intensely interesting presentation of it, based on most extensive -original research, may be found in Adalbert Svoboda's distinguished -works, _The Illusion of the Soul_ and _Forms of Faith_. However absurd -and inconsistent with modern knowledge most of these myths seem to be, -they still play an important part, and, as "postulates of practical -reason," they exercise a powerful influence on the opinions of -individuals and on the destiny of races. - -The idealist and spiritualist philosophy of the day will freely grant -that these prevalent materialistic forms of belief in immortality are -untenable; it will say that the refined idea of an immaterial soul, -a Platonic "idea" or a transcendental psychic substance, must be -substituted for them. But modern realism can have nothing whatever to -do with these incomprehensible notions; they satisfy neither the mind's -feeling of causality nor the yearning of our emotions. If we take a -comprehensive glance at all that modern anthropology, psychology, -and cosmology teach with regard to athanatism, we are forced to this -definite conclusion: "The belief in the immortality of the human soul -is a dogma which is in hopeless contradiction with the most solid -empirical truths of modern science." - - - - -CHAPTER XII - -THE LAW OF SUBSTANCE - - The Fundamental Chemical Law of the Constancy of Matter--The - Fundamental Physical Law of the Conservation of Energy--Combination - of Both Laws in the Law of Substance--The Kinetic, Pyknotic, - and Dualistic Ideas of Substance--Monism of Matter--Ponderable - Matter--Atoms and Elements--Affinity of the Elements--The Soul of - the Atom (Feeling and Inclination)--Existence and Character of - Ether--Ether and Ponderable Matter--Force and Energy--Potential - and Actual Force--Unity of Natural Forces--Supremacy of the Law of - Substance - - -The supreme and all-pervading law of nature, the true and only -cosmological law, is, in my opinion, _the law of substance_; its -discovery and establishment is the greatest intellectual triumph of the -nineteenth century, in the sense that all other known laws of nature -are subordinate to it. Under the name of "law of substance" we embrace -two supreme laws of different origin and age--the older is the chemical -law of the "conservation of matter," and the younger is the physical -law of the "conservation of energy."[23] It will be self-evident to -many readers, and it is acknowledged by most of the scientific men of -the day, that these two great laws are essentially inseparable. This -fundamental thesis, however, is still much contested in some quarters, -and we must proceed to furnish the proof of it. But we must first -devote a few words to each of the two laws. - -The law of the "_persistence_" or "_indestructibility of matter_," -established by Lavoisier in 1789, may be formulated thus: The sum of -matter, which fills infinite space, is unchangeable. A body has merely -changed its form, when it seems to have disappeared. When coal burns, -it is changed into carbonic-acid gas by combination with the oxygen of -the atmosphere; when a piece of sugar melts in water, it merely passes -from the solid to the fluid condition. In the same way, it is merely -a question of change of form in the cases where a new body seems to -be produced. A shower of rain is the moisture of the atmosphere cast -down in the form of drops of water; when a piece of iron rusts, the -surface layer of the metal has combined with water and with atmospheric -oxygen, and formed a "rust," or oxyhydrate of iron. Nowhere in nature -do we find an example of the production, or "creation," of new matter; -nowhere does a particle of existing matter pass entirely away. This -empirical truth is now the unquestionable foundation of chemistry; it -may be directly verified at any moment by means of the balance. To the -great French chemist Lavoisier belongs the high merit of first making -this experiment with the balance. At the present day the scientist, who -is occupied from one end of the year to the other with the study of -natural phenomena, is so firmly convinced of the absolute "constancy" -of matter that he is no longer able to imagine the contrary state of -things. - -We may formulate the "_law of the persistence of force_" or -"_conservation of energy_" thus: The sum of force, which is at work in -infinite space and produces all phenomena, is unchangeable. When the -locomotive rushes along the line, the potential energy of the steam -is transformed into the kinetic or actual energy of the mechanical -movement; when we hear its shrill whistle, as it speeds along, the -sound-waves of the vibrating atmosphere are conveyed through the -tympanum and the three bones of the ear into the inner labyrinth, and -thence transferred by the auditory nerve to the acoustic ganglionic -cells which form the centre of hearing in the temporal lobe of the -gray bed of the brain. The whole marvellous panorama of life that -spreads over the surface of our globe is, in the last analysis, -transformed sunlight. It is well known how the remarkable progress of -technical science has made it possible for us to convert the different -physical forces from one form to another; heat may be changed into -molar movement, or movement of mass; this in turn into light or sound, -and then into electricity, and so forth. Accurate measurement of -the quantity of force which is used in this metamorphosis has shown -that it is "constant" or unchanged. No particle of living energy is -ever extinguished; no particle is ever created anew. Friedrich Mohr, -of Bonn, was very near to the discovery of this great fact in 1837, -but the discovery was actually made by the able Swabian physician, -Robert Mayer, of Heilbronn, in 1842. Independently of Mayer, however, -the principle was reached almost at the same time by the famous -physiologist, Hermann Helmholtz; five years afterwards he pointed out -its general application to, and fertility in, every branch of physics. -We ought to say to-day that it rules also in the entire province of -physiology--that is, of "organic physics"; but on that point we meet -a strenuous opposition from the vitalistic biologists and the dualist -and spiritualist philosophers. For these the peculiar "spiritual -forces" of human nature are a group of "free" forces, not subject to -the law of energy; the idea is closely connected with the dogma of the -"freedom of the will." We have, however, already seen (p. 204) that the -dogma is untenable. Modern physics draws a distinction between "force" -and "energy," but our general observations so far have not needed a -reference to it. - -The conviction that these two great cosmic theorems, the chemical law -of the persistence of matter and the physical law of the persistence -of force, are fundamentally one, is of the utmost importance in our -monistic system. The two theories are just as intimately united as -their objects--matter and force or energy. Indeed, this fundamental -unity of the two laws is self-evident to many monistic scientists and -philosophers, since they merely relate to two different aspects of one -and the same object, the _cosmos_. But, however natural the thought may -be, it is still very far from being generally accepted. It is stoutly -contested by the entire dualistic philosophy, vitalistic biology, -and parallelistic psychology; even, in fact, by a few (inconsistent) -monists, who think they find a check to it in "consciousness," in the -higher mental activity of man, or in other phenomena of our "free -mental life." - -For my part, I am convinced of the profound importance of the unifying -"law of substance," as an expression of the inseparable connection in -reality of two laws which are only separated in conception. That they -were not originally taken together and their unity recognized from -the beginning is merely an accident of the date of their respective -discoveries. The earlier and more accessible chemical law of the -persistence of matter was detected by Lavoisier in 1789, and, after -a general application of the balance, became the basis of exact -chemistry. On the other hand, the more recondite law of the persistence -of force was only discovered by Mayer in 1842, and only laid down -as the basis of exact physics by Helmholtz. The unity of the two -laws--still much disputed--is expressed by many scientists who are -convinced of it in the formula: "Law of the persistence of matter and -force." In order to have a briefer and more convenient expression for -this fundamental thought, I proposed some time ago to call it the "law -of substance" or the "fundamental cosmic law"; it might also be called -the "universal law," or the "law of constancy," or the "axiom of the -constancy of the universe." In the ultimate analysis it is found to be -a necessary consequence of the principle of causality.[24] - -The first thinker to introduce the purely monistic conception of -substance into science and appreciate its profound importance was the -great philosopher Baruch Spinoza; his chief work appeared shortly after -his premature death in 1677, just one hundred years before Lavoisier -gave empirical proof of the constancy of matter by means of the -chemist's principal instrument, the balance. In his stately pantheistic -system the notion of the _world_ (the universe, or the cosmos) is -identical with the all-pervading notion of God; it is at one and the -same time the purest and most rational _monism_ and the clearest and -most abstract _monotheism_. This universal substance, this "divine -nature of the world," shows us two different aspects of its being, or -two fundamental attributes--matter (infinitely _extended_ substance) -and spirit (the all-embracing energy of _thought_). All the changes -which have since come over the idea of substance are reduced, on a -logical analysis, to this supreme thought of Spinoza's; with Goethe -I take it to be the loftiest, profoundest, and truest thought of all -ages. Every single object in the world which comes within the sphere -of our cognizance, all individual forms of existence, are but special -transitory forms--_accidents_ or _modes_--of substance. These modes are -material things when we regard them under the attribute of _extension_ -(or "occupation of space"), but forces or ideas when we consider them -under the attribute of _thought_ (or "energy"). To this profound -thought of Spinoza our purified monism returns after a lapse of two -hundred years; for us, too, matter (space-filling substance) and energy -(moving force) are but two inseparable attributes of the one underlying -substance. - -Among the various modifications which the fundamental idea of substance -has undergone in modern physics, in association with the prevalent -atomism, we shall select only two of the most divergent theories for -a brief discussion, the kinetic and the pyknotic. Both theories agree -that we have succeeded in reducing all the different forces of nature -to one common original force; gravity and chemical action, electricity -and magnetism, light and heat, etc., are only different manifestations, -forms, or _dynamodes_, of a single primitive force (_prodynamis_). -This fundamental force is generally conceived as a vibratory motion -of the smallest particles of matter--a vibration of atoms. The atoms -themselves, according to the usual "kinetic theory of substance," are -dead, separate particles of matter, which dance to and fro in empty -space and act at a distance. The real founder and most distinguished -representative of the kinetic theory is Newton, the famous discoverer -of the law of gravitation. In his great work, the _Philosophiae -Naturalis Principia Mathematica_ (1687), he showed that throughout the -universe the same law of attraction controls the unvarying constancy of -gravitation; the attraction of two particles being in direct proportion -to their mass and in inverse proportion to the square of their -distance. This universal force of gravity is at work in the fall of -an apple and the tidal wave no less than in the course of the planets -round the sun and the movements of all the heavenly bodies. Newton -had the immortal merit of establishing the law of gravitation and -embodying it in an indisputable mathematical formula. Yet this _dead -mathematical formula_, on which most scientists lay great stress, as so -frequently happens, gives us merely the _quantitative_ demonstration -of the theory; it gives us no insight whatever into the _qualitative_ -nature of the phenomena. The action at a distance without a medium, -which Newton deduced from his law of gravitation, and which became one -of the most serious and most dangerous dogmas of later physics, does -not afford the slightest explanation of the real causes of attraction; -indeed, it long obstructed our way to the real discovery of them. I -cannot but suspect that his speculations on this mysterious action at a -distance contributed not a little to the leading of the great English -mathematician into the obscure labyrinth of mystic dreams and theistic -superstition in which he passed the last thirty-four years of his -life; we find him, at the end, giving metaphysical hypotheses on the -predictions of Daniel and on the paradoxical fantasies of St. John. - -In fundamental opposition to the theory of vibration, or the kinetic -theory of substance, we have the modern "theory of condensation," -or the pyknotic theory of substance. It is most ably established -in the suggestive work of J. C. Vogt on _The Nature of Electricity -and Magnetism on the Basis of a Simplified Conception of Substance_ -(1891). Vogt assumes the primitive force of the world, the universal -_prodynamis_, to be, not the vibration or oscillation of particles in -empty space, but the condensation of a simple primitive substance, -which fills the infinity of space in an unbroken continuity. Its -sole inherent mechanical form of activity consists in a tendency to -condensation or contraction, which produces infinitesimal centres -of condensation; these may change their degree of thickness, and, -therefore, their volume, but are constant as such. These minute parts -of the universal substance, the centres of condensation, which might -be called _pyknatoms_, correspond in general to the ultimate separate -atoms of the kinetic theory; they differ, however, very considerably in -that they are credited with sensation and inclination (or will-movement -of the simplest form), _with souls_, in a certain sense--in harmony -with the old theory of Empedocles of the "love and hatred of the -elements." Moreover, these "atoms with souls" do not float in empty -space, but in the continuous, extremely attenuated intermediate -substance, which represents the uncondensed portion of the primitive -matter. By means of certain "constellations, centres of perturbation, -or systems of deformation," great masses of centres of condensation -quickly unite in immense proportions, and so obtain a preponderance -over the surrounding masses. By that process the primitive substance, -which in its original state of quiescence had the same mean consistency -throughout, divides or differentiates into two kinds. The centres -of disturbance, which _positively_ exceed the mean consistency in -virtue of the _pyknosis_ or condensation, form the ponderable matter -of bodies; the finer, intermediate substance, which occupies the space -between them, and _negatively_ falls below the mean consistency, forms -the ether, or imponderable matter. As a consequence of this division -into mass and ether there ensues a ceaseless struggle between the two -antagonistic elements, and this struggle is the source of all physical -processes. The positive ponderable matter, the element with the feeling -of like or desire, is continually striving to complete the process of -condensation, and thus collecting an enormous amount of _potential_ -energy; the negative, imponderable matter, on the other hand, offers a -perpetual and equal resistance to the further increase of its strain -and of the feeling of dislike connected therewith, and thus gathers the -utmost amount of _actual_ energy. - -We cannot go any further here into the details of the brilliant -theory of J. C. Vogt. The interested reader cannot do better than -have recourse to the second volume of the above work for a clear, -popular exposition of the difficult problem. I am myself too little -informed in physics and mathematics to enter into a critical discussion -of its lights and shades; still, I think that this pyknotic theory -of substance will prove more acceptable to every biologist who is -convinced of the unity of nature than the kinetic theory which prevails -in physics to-day. A misunderstanding may easily arise from the fact -that Vogt puts his process of condensation in explicit contradiction -with the general phenomenon of motion; but it must be remembered that -he is speaking of vibratory movement in the sense of the physicist. His -hypothetical "condensation" is just as much determined by a movement -of substance as is the hypothetical "vibration"; only the kind of -movement and the relation of the moving elements are very different in -the two hypotheses. Moreover, it is not the whole theory of vibration, -but only an important section of it, that is contradicted by the theory -of condensation. - -Modern physics, for the most part, still firmly adheres to the older -theory of vibration, to the idea of an _actio in distans_ and the -eternal vibration of dead atoms in empty space; it rejects the pyknotic -theory. Although Vogt's theory may be still far from perfect, and his -original speculations may be marred by many errors, yet I think he has -rendered a very good service in eliminating the untenable principles -of the kinetic theory of substance. As to my own opinion--and that of -many other scientists--I must lay down the following theses, which -are involved in Vogt's pyknotic theory, as indispensable for a truly -monistic view of substance, and one that covers the whole field of -organic and inorganic nature: - -I. The two fundamental forms of substance, ponderable matter and ether, -are not dead and only moved by extrinsic force, but they are endowed -with sensation and will (though, naturally, of the lowest grade); they -experience an inclination for condensation, a dislike of strain; they -strive after the one and struggle against the other. - -II. There is no such thing as empty space; that part of space which is -not occupied with ponderable atoms is filled with ether. - -III. There is no such thing as an action at a distance through -perfectly empty space; all action of bodies upon each other is either -determined by immediate contact or is effected by the mediation of -ether. - -Both the theories of substance which we have just contrasted are -_monistic_ in principle, since the opposition between the two -conditions of substance--mass and ether--is not original; moreover, -they involve a continuous immediate contact and reciprocal action -of the two elements. It is otherwise with the _dualistic_ theories -of substance which still obtain in the idealist and spiritualist -philosophy, and which have the support of a powerful theology, in so -far as theology indulges in such metaphysical speculations. These -theories draw a distinction between two entirely different kinds of -substance, material and immaterial. Material substance enters into -the composition of the bodies which are the object of physics and -chemistry; the law of the persistence of matter and force is confined -to this world (apart from a belief in its "creation from nothing" -and other miracles). Immaterial substance is found in the "spiritual -world" to which the law does not extend; in this province the laws -of physics and chemistry are either entirely inapplicable or they -are subordinated to a "vital force," or a "free will," or a "divine -omnipotence," or some other phantom which is beyond the ken of critical -science. In truth, these profound errors need no further refutation -to-day, for experience has never yet discovered for us a single -immaterial substance, a single force which is not dependent on matter, -or a single form of energy which is not exerted by material movement, -whether it be of mass, or of ether, or of both. Even the most elaborate -and most perfect forms of energy that we know--the psychic life of -the higher animals, the thought and reason of man--depend on material -processes, or changes in the neuroplasm of the ganglionic cells; they -are inconceivable apart from such modifications. I have already shown -(chap. xi.) that the physiological hypothesis of a special, immaterial -"soul-substance" is untenable. - -The study of ponderable matter is primarily the concern of chemistry. -Few are ignorant of the astonishing theoretical progress which this -science has made in the course of the century and the immense practical -influence it has had on every aspect of modern life. We shall confine -ourselves here to a few remarks on the more important questions -which concern the nature of ponderable matter. It is well known that -analytical chemistry has succeeded in resolving the immense variety -of bodies in nature into a small number of simple elements--that is, -simple bodies which are incapable of further analysis. The number of -these elements is about seventy. Only fourteen of them are widely -distributed on the earth and of much practical importance; the majority -are rare elements (principally metals) of little practical moment. The -affinity of these groups of elements, and the remarkable proportions of -their atomic weights, which Lothar Meyer and Mendelejeff have proved -in their _Periodic System of the Elements_, make it extremely probable -that they are not _absolute species_ of ponderable matter--that is, -not eternally unchangeable particles. The seventy elements have in -that system been distributed into eight leading groups, and arranged -in them according to their atomic weight, so that the elements which -have a chemical affinity are formed into families. The relations of -the various groups in such a natural system of the elements recall, -on the one hand, similar relations of the innumerable compounds of -carbon, and, again, the relations of parallel groups in the natural -arrangement of the animal and plant species. Since in the latter -cases the "affinity" of the related forms is based on descent from a -common parent form, it seems very probable that the same holds good of -the families and orders of the chemical elements. We may, therefore, -conclude that the "empirical elements" we now know are not really -simple, ultimate, and unchangeable forms of matter, but compounds -of homogeneous, simple, primitive atoms, variously distributed as -to number and grouping. The recent speculations of Gustav Wendt, -Wilhelm Preyer, Sir W. Crookes, and others, have pointed out how we -may conceive the evolution of the elements from a simple primitive -material, the _prothyl_. - -The modern atomistic theory, which is regarded as an indispensable -instrument in chemistry to-day, must be carefully distinguished from -the old philosophic atomism which was taught more than two thousand -years ago by a group of distinguished thinkers of antiquity--Leucippus, -Democritus, and Epicurus: it was considerably developed and modified -later on by Descartes, Hobbes, Leibnitz, and other famous philosophers. -But it was not until 1808 that modern atomism assumed a definite and -acceptable form, and was furnished with an empirical basis by Dalton, -who formulated the "law of simple and multiple proportions" in the -formation of chemical combinations. He first determined the atomic -weight of the different elements, and thus created the solid and exact -foundation on which more recent chemical theories are based; these -are all _atomistic_, in the sense that they assume the elements to be -made up of homogeneous, infinitesimal, distinct particles, which are -incapable of further analysis. That does not touch the question of the -real nature of the atoms--their form, size, psychology, etc. These -atomic qualities are merely hypothetical; while the _chemistry_ of the -atoms, their "chemical affinity"--that is, the constant proportion in -which they combine with the atoms of other elements--is empirical.[25] - -The different relation of the various elements towards each other, -which chemistry calls "affinity," is one of the most important -properties of ponderable matter; it is manifested in the different -relative quantities or proportions of their combination in the -intensity of its consummation. Every shade of inclination, from -complete indifference to the fiercest passion, is exemplified in the -chemical relation of the various elements towards each other, just -as we find in the psychology of man, and especially in the life of -the sexes. Goethe, in his classical romance, _Affinities_, compared -the relations of pairs of lovers with the phenomenon of the same name -in the formation of chemical combinations. The irresistible passion -that draws Edward to the sympathetic Ottilia, or Paris to Helen, and -leaps over all bounds of reason and morality, is the same powerful -"unconscious" attractive force which impels the living spermatozoon to -force an entrance into the ovum in the fertilization of the egg of the -animal or plant--the same impetuous movement which unites two atoms -of hydrogen to one atom of oxygen for the formation of a molecule of -water. This fundamental _unity of affinity in the whole of nature_, -from the simplest chemical process to the most complicated love story, -was recognized by the great Greek scientist, Empedocles, in the fifth -century B.C., in his theory of "the love and hatred of the elements." -It receives empirical confirmation from the interesting progress of -cellular psychology, the great significance of which we have only -learned to appreciate in the last thirty years. On those phenomena we -base our conviction that even the _atom_ is not without a rudimentary -form of sensation and will, or as it is better expressed, of feeling -(_aesthesis_) and inclination (_tropesis_)--that is, a universal "soul" -of the simplest character. The same must be said of the molecules which -are composed of two or more atoms. Further combinations of different -kinds of these molecules give rise to simple and, subsequently, complex -chemical compounds, in the activity of which the same phenomena are -repeated in a more complicated form. - -The study of ether, or imponderable matter, pertains principally to -physics. The existence of an extremely attenuated medium, filling the -whole of space outside of ponderable matter, was known and applied -to the elucidation of various phenomena (especially light) a long -time ago; but it was not until the second half of the nineteenth -century that we became more closely acquainted with this remarkable -substance, in connection with our astonishing empirical discoveries in -the province of electricity, with their experimental detection, their -theoretical interpretation, and their practical application. The path -was opened in particular by the famous researches of Heinrich Hertz, of -Bonn, in 1888. The premature death of a brilliant young physicist of so -much promise cannot be sufficiently deplored. Like the premature death -of Spinoza, Raphael, Schubert, and many other great men, it is one of -those brutal facts of human history which are enough of themselves to -destroy the untenable myth of a "wise Providence" and an "All-loving -Father in heaven." - -The existence of ether (or cosmic ether) as a real element is a -_positive fact_, and has been known as such for the last twelve years. -We sometimes read even to-day that ether is a "pure hypothesis"; -this erroneous assertion comes not only from uninformed philosophers -and "popular" writers, but even from certain "prudent and exact -physicists." But there would be just as much reason to deny the -existence of ponderable matter. As a matter of fact, there are -metaphysicians who accomplish even this feat, and whose highest wisdom -lies in denying or calling into question the existence of an external -universe; according to them only one real entity exists--their own -precious personality, or, to be more correct, their immortal soul. -Several modern physiologists have embraced this ultra-idealist view, -which is to be found in Descartes, Berkeley, Fichte, and others. -Their "psycho-monism" affirms: "One thing only exists, and that is -my own mind." This audacious spiritualism seems to us to rest on an -erroneous inference from Kant's correct critical theory, that we can -know the outer world only in the phenomenal aspect which is accessible -to our human organs of thought--the brain and the organs of sense. If -by those means we can attain only an imperfect and limited knowledge -of the material world, that is no reason for denying its existence -altogether. In my opinion, the existence of ether is as certain as that -of ponderable matter--as certain as my own existence, as I reflect and -write on it. As we assure ourselves of the existence of ponderable -matter by its mass and weight, by chemical and mechanical experiments, -so we prove that of ether by the experiences and experiments of optics -and electricity. - -Although, however, the existence of ether is now regarded as a -positive fact by nearly all physicists, and although many effects of -this remarkable substance are familiar to us through an extensive -experience, especially in the way of optical and electrical experiments, -yet we are still far from being clear and confident as to its real -character. The views of the most eminent physicists, who have made -a special study of it, are extremely divergent; they frequently -contradict each other on the most important points. One is, therefore, -free to choose among the contradictory hypotheses according to one's -knowledge and judgment. I will put in the following eight theses the -view which has approved itself to me after mature reflection on the -subject, though I am no expert in this department: - -I. Ether fills the whole of space, in so far as it is not occupied by -ponderable matter, as a _continuous substance_; it fully occupies the -space between the atoms of ponderable matter. - -II. Ether has probably no chemical quality, and is not composed of -atoms. If it be supposed that it consists of minute homogeneous atoms -(for instance, indivisible etheric particles of a uniform size), it -must be further supposed that there is something else between these -atoms, either "empty space" or a third, completely unknown medium, a -purely hypothetical "interether"; the question as to the nature of this -brings us back to the original difficulty, and so on _in infinitum_. - -III. As the idea of an empty space and an action at a distance is -scarcely possible in the present condition of our knowledge (at least -it does not help to a clear monistic view), I postulate for ether a -special structure which is not atomistic, like that of ponderable -matter, and which may provisionally be called (without further -determination) _etheric_ or _dynamic_ structure. - -IV. The consistency of ether is also peculiar, on our hypothesis, and -different from that of ponderable matter. It is neither gaseous, as -some conceive, nor solid, as others suppose; the best idea of it can be -formed by comparison with an extremely attenuated, elastic, and light -jelly. - -V. Ether may be called _imponderable_ matter in the sense that we -have no means of determining its weight experimentally. If it really -has weight, as is very probable, it must be so slight as to be far -below the capacity of our most delicate balance. Some physicists have -attempted to determine its weight by the energy of the light-waves, and -have discovered that it is some fifteen trillion times lighter than -atmospheric air; on that hypothesis a sphere of ether of the size of -our earth would weigh at least two hundred and fifty pounds(?). - -VI. The etheric consistency may probably (in accordance with the -pyknotic theory) pass into the gaseous state under certain conditions -by progressive condensation, just as a gas may be converted into a -fluid, and ultimately into a solid, by lowering its temperature. - -VII. Consequently, these three conditions of matter may be arranged -(and it is a point of great importance in our monistic cosmogony) in a -genetic, continuous order. We may distinguish five stages in it: (1) -the etheric, (2) the gaseous, (3) the fluid, (4) the viscous (in the -living protoplasm), and (5) the solid state. - -VIII. Ether is boundless and immeasurable, like the space it occupies. -It is in eternal motion; and this specific movement of ether (it is -immaterial whether we conceive it as vibration, strain, condensation, -etc.), in reciprocal action with mass-movement (or gravitation), is the -ultimate cause of all phenomena. - -"The great question of the nature of ether," as Hertz justly calls -it, includes the question of its relation to ponderable matter; for -these two forms of matter are not only always in the closest external -contact, but also in eternal, dynamic, reciprocal action. We may divide -the most general phenomena of nature, which are distinguished by -physics as natural forces or "functions of matter," into two groups; -the first of them may be regarded mainly (though not exclusively) as a -function of ether, and the second a function of ponderable matter--as -in the following scheme which I take from my _Monism_: - - THE WORLD (NATURE, OR THE COSMOS) - - ---------------------------------+------------------------------------- - ETHER--Imponderable. | MASS--Ponderable. - ---------------------------------+------------------------------------- - | - 1. _Consistency_: | 1. _Consistency_: - | - Etheric (_i.e._, neither | Not etheric (but gaseous, fluid, - gaseous nor fluid, nor solid). | or solid). - | - 2. _Structure_: | 2. _Structure_: - | - Not atomistic, not made up of | Atomistic, made up of infinitesimal, - separate particles (atoms), but | distinct particles (atoms) - continuous. | discontinuous. - | - 3. _Chief Functions_: | 3. _Chief Functions_: - | - Light, radiant heat, electricity,| Gravity, inertia, molecular heat, - and magnetism. | and chemical affinity. - ---------------------------------+------------------------------------- - -The two groups of functions of matter, which we have opposed in this -table, may, to some extent, be regarded as the outcome of the first -"division of labor" in the development of matter, the "primary ergonomy -of matter." But this distinction must not be supposed to involve an -absolute separation of the two antithetic groups; they always retain -their connection, and are in constant reciprocal action. It is well -known that the optical and electrical phenomena of ether are closely -connected with mechanical and chemical changes in ponderable elements; -the radiant heat of ether may be directly converted into the mechanical -heat of the mass; gravitation is impossible unless the ether effects -the mutual attraction of the separated atoms, because we cannot admit -the idea of an _actio in distans_. In like manner, the conversion -of one form of energy into another, as indicated in the law of the -persistence of force, illustrates the constant reciprocity of the two -chief types of substance, ether and mass. - -The great law of nature, which, under the title of the "law of -substance," we put at the head of all physical considerations, was -conceived as the law of "the persistence of force" by Robert Meyer, who -first formulated it, and Helmholtz, who continued the work. Another -German scientist, Friedrich Mohr, of Bonn, had clearly outlined it in -its main features ten years earlier (1837). The old idea of _force_ -was, after a time, differentiated by modern physics from that of -_energy_, which was at first synonymous with it. Hence the law is -now usually called the "law of the persistence of energy." However, -this finer distinction need not enter into the general consideration, -to which I must confine myself here, and into the question of the -great principle of the "persistence of substance." The interested -reader will find a very clear treatment of the question in Tyndall's -excellent paper on "The Fundamental Law of Nature," in his _Fragments -of Science_. It fully explains the broad significance of this profound -cosmic law, and points out its application to the main problems of -very different branches of science. We shall confine our attention to -the important fact that the "principle of energy" and the correlative -idea of the unity of natural forces, on the basis of a common origin, -are now accepted by all competent physicists, and are regarded as the -greatest advance of physics in the nineteenth century. We now know that -heat, sound, light, chemical action, electricity, and magnetism are all -modes of motion. We can, by a certain apparatus, convert any one of -these forces into another, and prove by an accurate measurement that -not a single particle of energy is lost in the process. - -The sum-total of force or energy in the universe remains constant, no -matter what changes take place around us; it is eternal and infinite, -like the matter on which it is inseparably dependent. The whole drama -of nature apparently consists in an alternation of movement and -repose; yet the bodies at rest have an inalienable quantity of force, -just as truly as those that are in motion. It is in this movement -that the potential energy of the former is converted into the kinetic -energy of the latter. "As the principle of the persistence of force -takes into account repulsion as well as attraction, it affirms that -the mechanical value of the potential energy and the kinetic energy -in the material world is a constant quantity. To put it briefly, the -force of the universe is divided into two parts, which may be mutually -converted, according to a fixed relation of value. The diminution of -the one involves the increase of the other; the total value remains -unchanged in the universe." The potential energy and the actual, or -kinetic, energy are being continually transformed from one condition to -the other; but the infinite sum of force in the world at large never -suffers the slightest curtailment. - -Once modern physics had established the law of substance as far as -the simpler relations of inorganic bodies are concerned, physiology -took up the story, and proved its application to the entire province -of the organic world. It showed that all the vital activities of the -organism--without exception--are based on a constant "reciprocity -of force" and a correlative change of material, or metabolism, just -as much as the simplest processes in "lifeless" bodies. Not only -the growth and the nutrition of plants and animals, but even their -functions of sensation and movement, their sense-action and psychic -life, depend on the conversion of potential into kinetic energy, -and _vice versâ_. This supreme law dominates also those elaborate -performances of the nervous system which we call, in the higher animals -and man, "the action of the mind." - -Our monistic view, that the great cosmic law applies throughout the -whole of nature, is of the highest moment. For it not only involves, -on its positive side, the essential unity of the cosmos and the -causal connection of all phenomena that come within our cognizance, -but it also, in a negative way, marks the highest intellectual -progress, in that it definitely rules out the three central dogmas of -metaphysics--God, freedom, and immortality. In assigning mechanical -causes to phenomena everywhere, the law of substance comes into line -with the universal law of causality. - - - - -CHAPTER XIII - -THE EVOLUTION OF THE WORLD - - The Notion of Creation--Miracles--Creation of the Whole Universe - and of its Various Parts--Creation of Substance (Cosmological - Creation)--Deism: One Creative Day--Creation of Separate - Entities--Five Forms of Ontological Creationism--Theory of - Evolution--I. Monistic Cosmogony--Beginning and End of the - World--The Infinity and Eternity of the Universe--Space and - Time--_Universum perpetuum mobile_--Entropy of the Universe--II. - Monistic Geogeny--History of the Inorganic and Organic Worlds--III. - Monistic Biogeny--Transformism and the Theory of Descent: Lamarck - and Darwin--IV. Monistic Anthropogeny--Origin of Man - - -The greatest, vastest, and most difficult of all cosmic problems is -that of the origin and development of the world--the "question of -creation," in a word. Even to the solution of this most difficult -world-riddle the nineteenth century has contributed more than all its -predecessors; in a certain sense, indeed, it has found the solution. We -have at least attained to a clear view of the fact that all the partial -questions of creation are indivisibly connected, that they represent -one single, comprehensive "cosmic problem," and that the key to this -problem is found in the one magic word--evolution. The great questions -of the creation of man, the creation of the animals and plants, the -creation of the earth and the sun, etc., are all parts of the general -question, What is the origin of the whole world? Has it been _created_ -by supernatural power, or has it been _evolved_ by a natural process? -What are the causes and the manner of this evolution? If we succeed -in finding the correct answer to one of these questions, we have, -according to our monistic conception of the world, cast a brilliant -light on the solution of them all, and on the entire cosmic problem. - -The current opinion as to the origin of the world in earlier ages was -almost a universal belief in creation. This belief has been expressed -in thousands of interesting, more or less fabulous, legends, poems, -cosmogonies, and myths. A few great philosophers were devoid of it, -especially those remarkable free-thinkers of classical antiquity who -first conceived the idea of natural evolution. All the creation-myths, -on the contrary, were of a supernatural, miraculous, and transcendental -character. Incompetent, as it was, to investigate for itself the -nature of the world and its origin by natural causes, the undeveloped -mind naturally had recourse to the idea of miracle. In most of these -creation-myths _anthropism_ was blended with the belief in the -miraculous. The creator was supposed to have constructed the world on a -definite plan, just as man accomplishes his artificial constructions; -the conception of the creator was generally completely anthropomorphic, -a palpable "anthropistic creationism." The "all-mighty maker of heaven -and earth," as he is called in Genesis and the Catechism, is just as -humanly conceived as the modern creator of Agassiz and Reinke, or the -intelligent "engineer" of other recent biologists. - -Entering more fully into the notion of creation, we can distinguish -as two entirely different acts the production of the universe as a -whole and the partial production of its various parts, in harmony with -Spinoza's idea of _substance_ (the universe) and _accidents_ (or -_modes_, the individual phenomena of substance). This distinction is of -great importance, because there are many eminent philosophers who admit -the one and reject the other. - -According to this creationist theory, then, God has "made the world -out of nothing." It is supposed that God (a rational, but immaterial, -being) existed by himself for an eternity before he resolved to create -the world. Some supporters of the theory restrict God's creative -function to one single act; they believe that this extramundane God -(the rest of whose life is shrouded in mystery) created the substance -of the world in a single moment, endowed it with the faculty of -the most extensive evolution, and troubled no further about it. -This view may be found, for instance, in the English Deists in many -forms. It approaches very close to our monistic theory of evolution, -only abandoning it in the one instant in which God accomplished the -creation. Other creationists contend that God did not confine himself -to the mere creation of matter, but that he continues to be operative -as the "sustainer and ruler of the world." Different modifications of -this belief are found, some approaching very close to _pantheism_ and -others to complete _theism_. All these and similar forms of belief in -creation are incompatible with the law of the persistence of matter and -force; that law knows nothing of a beginning. - -It is interesting to note that E. du Bois-Reymond has identified -himself with this cosmological creationism in his latest speech -(on "Neovitalism," 1894). "It is more consonant with the divine -omnipotence," he says, "to assume that it created the whole material -of the world in one creative act unthinkable ages ago in such -wise that it should be endowed with inviolable laws to control the -origin and the progress of living things--that, for instance, here -on earth rudimentary organisms should arise from which, without -further assistance, the whole of living nature could be evolved, from -a primitive bacillus to the graceful palm-wood, from a primitive -micrococcus to Solomon's lovely wives or to the brain of Newton. -Thus we are content with _one_ creative day, and we derive organic -nature mechanically, without the aid of either old or new vitalism." -Du Bois-Reymond here shows, as in the question of consciousness, the -shallow and illogical character of his monistic thought. - -According to another still prevalent theory, which may be called -"ontological creationism," God not only created the world at large, -but also its separate contents. In the Christian world the old Semitic -legend of creation, taken from Genesis, is still very widely accepted; -even among modern scientists it finds an adherent here and there. I -have fully entered into the criticism of it in the first chapter of my -_Natural History of Creation_. The following theories may be enumerated -as the most interesting modifications of this ontological creationism: - -I. _Dualistic creation._--God restricted his interference to _two_ -creative acts. First he created the inorganic world, mere dead -substance, to which alone the law of energy applies, working blindly -and aimlessly in the mechanism of material things and the building of -the mountains; then God attained intelligence and communicated it to -the purposive intelligent forces which initiate and control organic -evolution.[26] - -II. _Trialistic creation._--God made the world in _three_ creative -acts: (_a_) the creation of the heavens--the extra-terrestrial world, -(_b_) the creation of the earth (as the centre of the world) and of -its living inhabitants, and (_c_) the creation of man (in the image -and likeness of God). This dogma is still widely prevalent among -theologians and other "educated" people; it is taught as the truth in -many of our schools. - -III. _Heptameral creation_; a creation in seven days (_teste_ -Moses).--Although few educated people really believe in this Mosaic -myth now, it is still firmly impressed on our children in the biblical -lessons of their earliest years. The numerous attempts that have been -made, especially in England, to harmonize it with the modern theory of -evolution have entirely failed. It obtained some importance in science -when Linné adopted it in the establishment of his system, and based his -definition of organic species (which he considered to be unchangeable) -on it: "There are as many different species of animals and plants as -there were different forms created in the beginning by the Infinite." -This dogma was pretty generally held until the time of Darwin (1859), -although Lamarck had already proved its untenability in 1809. - -IV. _Periodic creation._--At the beginning of each period of the -earth's history the whole population of animals and plants was created -anew, and destroyed by a general catastrophe at its close; there were -as many general creative acts as there are distinct geological periods -(the catastrophic theory of Cuvier [1818] and Louis Agassiz [1858]). -Palæontology, which seemed to support this theory in its more imperfect -stage, has since completely refuted it. - -V. _Individual creation._--Every single man--and every individual -animal and plant--does not arise by a natural process of growth, but -is created by the favor of God. This view of creation is still often -met with in journals, especially in the "births" column. The special -talents and features of our children are often gratefully acknowledged -to be "gifts of God"; their hereditary defects fit into another theory. - -The error of these creation-legends and the cognate belief in miracles -must have been apparent to thoughtful minds at an early period; more -than two thousand years ago we find that many attempts were made -to replace them by a rational theory, and to explain the origin of -the world by natural causes. In the front rank, once more, we must -place the leaders of the Ionic school, with Democritus, Heraclitus, -Empedocles, Aristotle, Lucretius, and other ancient philosophers. The -first imperfect attempts which they made astonish us, in a measure, -by the flashes of mental light in which they anticipate modern ideas. -It must be remembered that classical antiquity had not that solid -groundwork for scientific speculation which has been provided by the -countless observations and experiments of modern scientists. During the -Middle Ages--especially during the domination of the papacy--scientific -work in this direction entirely ceased. The torture and the stake of -the Inquisition insured that an unconditional belief in the Hebrew -mythology should be the final answer to all the questions of creation. -Even the phenomena which led directly to the observation of the _facts_ -of evolution--the embryology of the plant and the animal, and of -man--remained unnoticed, or only excited the interest of an occasional -keen observer; but their discoveries were ignored or forgotten. -Moreover, the path to a correct knowledge of natural development was -barred by the dominant theory of preformation, the dogma which held -that the characteristic form and structure of each animal and plant -were already sketched in miniature in the germ (cf. p. 54). - -The science which we now call the science of evolution (in the broadest -sense) is, both in its general outline and in its separate parts, -a child of the nineteenth century; it is one of its most momentous -and most brilliant achievements. Almost unknown in the preceding -century, this theory has now become the sure foundation of our whole -world-system. I have treated it exhaustively in my _General Morphology_ -(1866), more popularly in my _Natural History of Creation_ (1868), and -in its special application to man in my _Anthropogeny_ (1874). Here I -shall restrict myself to a brief survey of the chief advances which -the science has made in the course of the century. It falls into four -sections, according to the nature of its object; that is, it deals with -the natural origin of (1) the cosmos, (2) the earth, (3) terrestrial -forms of life, and (4) man. - - -I.--MONISTIC COSMOGONY - -The first attempt to explain the constitution and the mechanical -origin of the world in a simple manner by "Newtonian laws"--that is, -by mathematical and physical laws--was made by Immanuel Kant in the -famous work of his youth (1755), _General History of the Earth and -Theory of the Heavens_. Unfortunately, this distinguished and daring -work remained almost unknown for ninety years; it was only disinterred -in 1845 by Alexander Humboldt in the first volume of his _Cosmos_. In -the mean time the great French mathematician, Pierre Laplace, had -arrived independently at similar views to those of Kant, and he gave -them a mathematical foundation in his _Exposition du Système du Monde_ -(1796). His chief work, the _Mécanique Céleste_, appeared a hundred -years ago. The analogous features of the cosmogony of Kant and Laplace -consist, as is well known, in a mechanical explanation of the movements -of the planets, and the conclusion which is drawn therefrom, that all -the cosmic bodies were formed originally by a condensation of rotating -nebulous spheres. This "nebular hypothesis" has been much improved -and supplemented since, but it is still the best of all the attempts -to explain the origin of the world on monistic and mechanical lines. -It has recently been strongly confirmed and enlarged by the theory -that this cosmogonic process did not simply take place once, but is -periodically repeated. While new cosmic bodies arise and develop out -of rotating masses of nebula in some parts of the universe, in other -parts old, extinct, frigid suns come into collision, and are once more -reduced by the heat generated to the condition of nebulæ. - -Nearly all the older and the more recent cosmogonies, including most -of those which were inspired by Kant and Laplace, started from the -popular idea that the world had had a beginning. Hence, according to -a widespread version of the nebular hypothesis, "in the beginning" -was made a vast nebula of infinitely attenuated and light material, -and at a certain moment ("countless ages ago") a movement of rotation -was imparted to this mass. Given this "first beginning" of the -cosmogonic movement, it is easy, on mechanical principles, to deduce -and mathematically establish the further phenomena of the formation of -the cosmic bodies, the separation of the planets, and so forth. This -first "origin of movement" is Du Bois-Reymond's second "world-enigma"; -he regards it as transcendental. Many other scientists and philosophers -are equally helpless before this difficulty; they resign themselves to -the notion that we have here a primary "supernatural impetus" to the -scheme of things, a "miracle." - -In our opinion, this second "world-enigma" is solved by the recognition -that movement is as innate and original a property of substance as -is sensation. The proof of this monistic assumption is found, first, -in the law of substance, and, secondly, in the discoveries which -astronomy and physics have made in the latter half of the century. By -the spectral analysis of Bunsen and Kirchhoff (1860) we have found, not -only that the millions of bodies, which fill the infinity of space, are -of the same material as our own sun and earth, but also that they are -in various stages of evolution; we have obtained by its aid information -as to the movements and distances of the stars, which the telescope -would never have given us. Moreover, the telescope itself has been -vastly improved, and has, in alliance with photography, made a host -of scientific discoveries of which no one dreamed at the beginning -of the century. In particular, a closer acquaintance with comets, -meteorites, star-clusters, and nebulæ has helped us to realize the -great significance of the smaller bodies which are found in millions in -the space between the stars. - -We now know that the _paths_ of the millions of heavenly bodies are -_changeable_, and to some extent irregular, whereas the planetary -system was formerly thought to be constant, and the rotating spheres -were described as pursuing their orbits in eternal regularity. -Astro-physics owes much of its triumph to the immense progress of other -branches of physics, of optics, and electricity, and especially of -the theory of ether. And here, again, our supreme law of substance is -found to be one of the most valuable achievements of modern science. -We now know that it rules unconditionally in the most distant reaches -of space, just as it does in our planetary system, in the most minute -particle of the earth as well as in the smallest cell of our human -frame. We are, moreover, justified in concluding, if we are not -logically compelled to conclude, that the persistence of matter and -force has held good throughout all time as it does to-day. Through all -eternity the infinite universe has been, and is, subject to the law of -substance. - -From this great progress of astronomy and physics, which mutually -elucidate and supplement each other, we draw a series of most important -conclusions with regard to the constitution and evolution of the -cosmos, and the persistence and transformation of substance. Let us put -them briefly in the following theses: - -I. The _extent_ of the universe is infinite and unbounded; it is empty -in no part, but everywhere filled with substance. - -II. The _duration_ of the world is equally infinite and unbounded; it -has no beginning and no end: it is eternity. - -III. Substance is everywhere and always in uninterrupted movement and -transformation: nowhere is there perfect repose and rigidity; yet the -infinite quantity of matter and of eternally changing force remains -constant. - -IV. This universal movement of substance in space takes the form of an -eternal cycle or of a periodical process of evolution. - -V. The phases of this evolution consist in a periodic change of -consistency, of which the first outcome is the primary division into -mass and ether--the ergonomy of ponderable and imponderable matter. - -VI. This division is effected by a progressive condensation of matter -as the formation of countless infinitesimal "centres of condensation," -in which the inherent primitive properties of substance--feeling and -inclination--are the active causes. - -VII. While minute and then larger bodies are being formed by this -pyknotic process in one part of space, and the intermediate ether -increases its strain, the opposite process--the destruction of cosmic -bodies by collision--is taking place in another quarter. - -VIII. The immense quantity of heat which is generated in this -mechanical process of the collision of swiftly moving bodies represents -the new kinetic energy which effects the movement of the resultant -nebulæ and the construction of new rotating bodies. The eternal drama -begins afresh. Even our mother earth, which was formed of part of the -gyrating solar system millions of ages ago, will grow cold and lifeless -after the lapse of further millions, and, gradually narrowing its -orbit, will fall eventually into the sun. - -It seems to me that these modern discoveries as to the periodic decay -and re-birth of cosmic bodies, which we owe to the most recent advance -of physics and astronomy, associated with the law of substance, are -especially important in giving us a clear insight into the universal -cosmic process of evolution. In their light our earth shrinks into the -slender proportions of a "mote in the sunbeam," of which unnumbered -millions chase each other through the vast depths of space. Our own -"human nature," which exalted itself into an image of God in its -anthropistic illusion, sinks to the level of a placental mammal, which -has no more value for the universe at large than the ant, the fly of -a summer's day, the microscopic infusorium, or the smallest bacillus. -Humanity is but a transitory phase of the evolution of an eternal -substance, a particular phenomenal form of matter and energy, the true -proportion of which we soon perceive when we set it on the background -of infinite space and eternal time. - -Since Kant explained space and time to be merely "forms of -perception"--space the form of external, time of internal, -sensitivity--there has been a keen controversy, which still continues, -over this important problem. A large section of modern metaphysicians -have persuaded themselves that this "critical fact" possesses a great -importance as the starting-point of "a purely idealist theory of -knowledge," and that, consequently, the natural opinion of the ordinary -healthy mind as to the _reality_ of time and space is swept aside. This -narrow and ultra-idealist conception of time and space has become a -prolific source of error. It overlooks the fact that Kant only touched -one side of the problem, the _subjective_ side, in that theory, and -recognized the equal validity of its _objective_ side. "Time and -space," he said, "have empirical reality, but transcendental ideality." -Our modern monism is quite compatible with this thesis of Kant's, -but not with the one-sided exaggeration of the subjective aspect of -the problem; the latter leads logically to the absurd idealism that -culminates in Berkeley's thesis, "Bodies are but ideas; their essence -is in their perception." The thesis should be read thus: "Bodies are -only ideas for my personal consciousness; their existence is just -as real as that of my organs of thought, the ganglionic cells in -the gray bed of my brain, which receive the impress of bodies on my -sense-organs and form those ideas by association of the impressions." It -is just as easy to doubt or to deny the reality of my own consciousness -as to doubt that of time and space. In the delirium of fever, in -hallucinations, in dreams, and in double-consciousness, I take ideas -to be true which are merely fancies. I mistake my own personality for -another (_vide_ p. 185); Descartes' famous _Cogito ergo sum_ applies no -longer. On the other hand, the reality of time and space is now fully -established by that expansion of our philosophy which we owe to the -law of substance and to our monistic cosmogony. When we have happily -got rid of the untenable idea of "empty space," there remains as the -infinite "space-filling"-medium matter, in its two forms of ether and -mass. So also we find a "time-filling" event in the eternal movement, -or genetic energy, which reveals itself in the uninterrupted evolution -of substance, in the _perpetuum mobile_ of the universe. - -As a body which has been set in motion continues to move as long as no -external agency interferes with it, the idea was conceived long ago of -constructing an apparatus which should illustrate perpetual motion. The -fact was overlooked that every movement meets with external impediments -and gradually ceases, unless a new impetus is given to it from without -and a new force is introduced to counteract the impediments. Thus, for -instance, a pendulum would swing backward and forward for an eternity -at the same speed if the resistance of the atmosphere and the friction -at the point it hangs from did not gradually deprive it of the -mechanical kinetic energy of its motion and convert it into heat. We -have to furnish it with fresh mechanical energy by a spring (or, as in -the pendulum-clock, by the drag of a weight). Hence it is impossible to -construct a machine that would produce, without external aid, a surplus -of energy by which it could keep itself going. Every attempt to make -such a _perpetuum mobile_ must necessarily fail; the discovery of the -law of substance showed, in addition, the theoretical impossibility of -it. - -The case is different, however, when we turn to the world at large, the -boundless universe that is in eternal movement. The infinite matter, -which fills it objectively, is what we call _space_ in our subjective -impression of it; _time_ is our subjective conception of its eternal -movement, which is, objectively, a periodic, cyclic evolution. These -two "forms of perception" teach us the infinity and eternity of the -universe. That is, moreover, equal to saying that the universe itself -is a _perpetuum mobile_. This infinite and eternal "machine of the -universe" sustains itself in eternal and uninterrupted movement, -because every impediment is compensated by an "equivalence of energy," -and the unlimited sum of kinetic and potential energy remains always -the same. The law of the persistence of force proves also that the idea -of a _perpetuum mobile_ is just as applicable to, and as significant -for, the cosmos as a whole as it is impossible for the isolated action -of any part of it. Hence the theory of _entropy_ is likewise untenable. - -The able founder of the mechanical theory of heat (1850), Clausius, -embodied the momentous contents of this important theory in two theses. -The first runs: "The energy of the universe is constant"--that is -one-half of our law of substance, the principle of energy (_vide_ p. -230). The second thesis is: "The energy of the universe tends towards -a maximum." In my opinion this second assertion is just as erroneous -as the first is true. In the theory of Clausius the entire energy of -the universe is of two kinds, one of which (heat of the higher degree, -mechanical, electrical, chemical energy, etc.) is partly convertible -into work, but the other is not; the latter energy, already converted -into heat and distributed in the cooler masses, is irrevocably lost as -far as any further work is concerned. Clausius calls this unconsumed -energy, which is no longer available for mechanical work, _entropy_ -(that is, force that is directed _inward_); it is continually -increasing at the cost of the other half. As, therefore, the mechanical -energy of the universe is daily being transformed into heat, and this -cannot be reconverted into mechanical force, the sum of heat and energy -in the universe must continually tend to be reduced and dissipated. All -difference of temperature must ultimately disappear, and the completely -latent heat must be equally distributed through one inert mass of -motionless matter. All organic life and movement must cease when this -maximum of _entropy_ has been reached. That would be a real "end of the -world." - -If this theory of entropy were true, we should have a "beginning" -corresponding to this assumed "end" of the world--a minimum of -entropy, in which the differences in temperature of the various parts -of the cosmos would be at a maximum. Both ideas are quite untenable -in the light of our monistic and consistent theory of the eternal -cosmogenetic process; both contradict the law of substance. There is -neither beginning nor end of the world. The universe is infinite, and -eternally in motion; the conversion of kinetic into potential energy, -and _vicissim_, goes on uninterruptedly; and the sum of this actual and -potential energy remains constant. The second thesis of the mechanical -theory of heat contradicts the first, and so must be rejected. - -The representatives of the theory of entropy are quite correct as long -as they confine themselves to distinct processes, in which, _under -certain conditions_, the latent heat cannot be reconverted into work. -Thus, for instance, in the steam-engine the heat can only be converted -into mechanical work when it passes from a warmer body (steam) into a -cooler (water); the process cannot be reversed. In the world at large, -however, quite other conditions obtain--conditions which permit the -reconversion of latent heat into mechanical work. For instance, in the -collision of two heavenly bodies, which rush towards each other at -inconceivable speed, enormous quantities of heat are liberated, while -the pulverized masses are hurled and scattered about space. The eternal -drama begins afresh--the rotating mass, the condensation of its parts, -the formation of new meteorites, their combination into larger bodies, -and so on. - - -II.--MONISTIC GEOGENY - -The history of the earth, of which we are now going to make a brief -survey, is only a minute section of the history of the cosmos. Like -the latter, it has been the object of philosophic speculation and -mythological fantasy for many thousand years. Its true scientific -study, however, is much younger; it belongs, for the most part, to -the nineteenth century. The fact that the earth is a planet revolving -round the sun was determined by the system of Copernicus (1543); -Galilei, Kepler, and other great astronomers, mathematically determined -its distance from the sun, the laws of its motion, and so forth. -Kant and Laplace indicated, in their cosmogony, the way in which the -earth had been developed from the parent sun. But the later history -of the earth, the formation of its crust, the origin of its seas and -continents, its mountains and deserts, was rarely made the subject -of serious scientific research in the eighteenth century, and in the -first two decades of the nineteenth. As a rule, men were satisfied with -unreliable conjectures or with the traditional story of creation; once -more the Mosaic legend barred the way to an independent investigation. - -In 1822 an important work appeared, which followed the same method -in the scientific investigation of the history of the earth that -had already proved the most fertile--the _ontological_ method, or -the principle of "actualism." It consists in a careful study and -manipulation of _actual_ phenomena with a view to the elucidation of -the analogous historical processes of the past. The Society of Science -at Göttingen had offered a prize in 1818 for "the most searching and -comprehensive inquiry into the changes in the earth's crust which are -historically demonstrable, and the application which may be made of a -knowledge of them in the investigation of the terrestrial revolutions -which lie beyond the range of history." This prize was obtained by Karl -Hoff, of Gotha, for his distinguished work, _History of the Natural -Changes in the Crust of the Earth in the Light of Tradition_ (1822-34). -Sir Charles Lyell then applied this _ontological_ or _actualistic_ -method with great success to the whole province of geology; his -_Principles of Geology_ (1830) laid the firm foundation on which -the fabric of the history of the earth was so happily erected. The -important geogenetic research of Alexander Humboldt, Leopold Buch, -Gustav Bischof, Edward Süss, and other geologists, were wholly based -on the empirical foundation and the speculative principles of Karl -Hoff and Charles Lyell. They cleared the way for purely rational -science in the field of geology; they removed the obstacles that had -been put in the path by mythological fancy and religious tradition, -especially by the Bible and its legends. I have already discussed the -merits of Lyell, and his relations with his friend Charles Darwin, -in the sixteenth and seventeenth chapters of my _Natural History of -Creation_, and must refer the reader to the standard works on geology -for a further acquaintance with the history of the earth and the great -progress which dynamical and historical geology have made during the -century. - -The first division of the history of the earth must be a separation -of inorganic and organic geogeny; the latter begins with the first -appearance of living things on our planet. The earlier section, the -inorganic history of the earth, ran much the same course as that of the -other planets of our system. They were all cast off as rings of nebula -at the equator of the rotating solar mass, and gradually condensed -into independent bodies. After cooling down a little, the glowing ball -of the earth was formed out of the gaseous mass, and eventually, as -the heat continued to radiate out into space, there was formed at its -surface the thin solid crust on which we live. When the temperature at -the surface had gone down to a certain point, the water descended upon -it from the environing clouds of steam, and thus the first condition -was secured for the rise of organic life. Many million years--certainly -more than a hundred--have passed since this important process of -the formation of water took place, introducing the third section of -cosmogony, which we call _biogeny_. - - -III.--MONISTIC BIOGENY - -The third phase of the evolution of the world opens with the advent of -organisms on our planet, and continues uninterrupted from that point -until the present day. The great problems which this most interesting -part of the earth's history suggests to us were still thought insoluble -at the beginning of the nineteenth century, or, at least, so difficult -that their solution seemed to be extremely remote. Now, at the close of -the century, we can affirm with legitimate pride that they have been -substantially solved by modern biology and its theory of transformism; -indeed, many of the phenomena of the organic world are now interpreted -on physical principles as completely as the familiar physical phenomena -of inorganic nature. The merit of making the first important step -in this difficult path and of pointing out the way to the monistic -solution of all the problems of biology must be accorded to the great -French scientist, Jean Lamarck; it was in 1809, the year of the -birth of Charles Darwin, that he published his famous _Philosophie -Zoologique_. In this original work not only is a splendid effort made -to interpret all the phenomena of organic life from a monistic and -physical point of view, but the path is opened which alone leads to -the solution of the greatest enigma of this branch of science--the -problem of the natural origin of organic species. Lamarck, who had an -equally extensive empirical acquaintance with zoology and botany, drew -the first sketch of the theory of descent; he showed that all the -countless members of the plant and animal kingdoms have arisen by slow -transformation from simple, common ancestral types, and that it is the -gradual modification of forms by _adaptation_, in reciprocal action -with _heredity_, which has brought about this secular metamorphosis. - -I have fully appreciated the merit of Lamarck in the fifth chapter, and -of Darwin in the sixth and seventh chapters, of the _Natural History -of Creation_. Darwin, fifty years afterwards, not only gave a solid -foundation to all the essential parts of the theory of descent, but he -filled up the _lacunae_ of Lamarck's work by his theory of selection. -Darwin reaped abundantly the success that Lamarck had never seen, -with all his merit. His epoch-making work on _The Origin of Species -by Natural Selection_ has transformed modern biology from its very -foundations, in the course of the last forty years, and has raised it -to a stage of development that yields to no other science in existence. -Darwin is _the Copernicus of the organic world_, as I said in 1868, and -E. du Bois-Reymond repeated fifteen years afterwards.[27] - - -IV.--MONISTIC ANTHROPOGENY - -The fourth and last phase of the world's history must be for us men -that latest period of time which has witnessed the development of our -own race. Lamarck (1809) had already recognized that this evolution is -only rationally conceivable as the outcome of a natural process, by -"descent from the apes," our next of kin among the mammals. Huxley then -proved, in his famous essay on _The Place of Man in Nature_, that this -momentous thesis is an inevitable consequence of the theory of descent, -and is thoroughly established by the facts of anatomy, embryology, and -palæontology. He considered this "question of all questions" to be -substantially answered. Darwin followed with a brilliant discussion -of the question under many aspects in his _Descent of Man_ (1871). -I had myself devoted a special chapter to this important problem of -the science of evolution in my _General Morphology_ (1866). In 1874 I -published my _Anthropogeny_, which contains the first attempt to trace -the descent of man through the entire chain of his ancestry right up to -the earliest archigonous monera; the attempt was based equally on the -three great "documents" of evolutionary science--anatomy, embryology, -and palæontology. The progress we have made in anthropogenetic research -during the last few years is described in the paper which I read on -"Our Present Knowledge of the Origin of Man" at the International -Congress of Zoologists at Cambridge in 1898.[28] - - - - -CHAPTER XIV - -THE UNITY OF NATURE - - The Monism of the Cosmos--Essential Unity of Organic - and Inorganic Nature--Carbon-Theory--The Hypothesis of - Abiogenesis--Mechanical and Purposive Causes--Mechanicism and - Teleology in Kant's Works--Design in the Organic and Inorganic - Worlds--Vitalism--Neovitalism--Dysteleology (the Moral of the - Rudimentary Organs)--Absence of Design in, and Imperfection of, - Nature--Telic Action in Organized Bodies--Its Absence in Ontogeny - and Phylogeny--The Platonist "Ideas"--No Moral Order Discoverable - in the History of the Organic World, of the Vertebrates, or of the - Human Race--Prevision--Design and Chance - - -One of the first things to be proved by the law of substance is the -basic fact that any natural force can be directly or indirectly -converted into any other. Mechanical and chemical energy, sound and -heat, light and electricity, are mutually convertible; they seem to be -but different modes of one and the same fundamental force or _energy_. -Thence follows the important thesis of the unity of all natural -forces, or, as it may also be expressed, the "monism of energy." -This fundamental principle is now generally recognized in the entire -province of physics and chemistry, as far as it applies to inorganic -substances. - -It seems to be otherwise with the organic world and its wealth of -color and form. It is, of course, obvious that a great part of the -phenomena of life may be immediately traced to mechanical and chemical -energy, and to the effects of electricity and light. For other vital -processes, however, especially for psychic activity and consciousness, -such an interpretation is vigorously contested. Yet the modern science -of evolution has achieved the task of constructing a bridge between -these two apparently irreconcilable provinces. We are now certain that -all the phenomena of organic life are subject to the universal law of -substance no less than the phenomena of the inorganic universe. - -The unity of nature which necessarily follows, and the demolition of -the earlier dualism, are certainly among the most valuable results of -modern evolution. Thirty-three years ago I made an exhaustive effort -to establish this "monism of the cosmos" and the essential unity of -organic and inorganic nature by a thorough, critical demonstration, -and a comparison of the accordance of these two great divisions of -nature with regard to matter, form, and force.[29] A short epitome of -the result is given in the fifteenth chapter of my _Natural History -of Creation_. The views I put forward are accepted by the majority -of modern scientists, but an attempt has been made in many quarters -lately to dispute them and to maintain the old antithesis of the two -divisions of nature. The ablest of these is to be found in the recent -_Welt als That_ of the botanist Reinke. It defends _pure cosmological_ -dualism with admirable lucidity and consistency, and only goes to prove -how utterly untenable the teleological system is that is connected -therewith. According to the author, physical and chemical forces alone -are at work in the entire field of inorganic nature, while in the -organic world we find "intelligent forces," regulative or dominant -forces. The law of substance is supposed to apply to the one, but not -to the other. On the whole, it is a question of the old antithesis of -a mechanical and a teleological system. But before we go more fully -into it, let us glance briefly at two other theories, which seem to -me to be of great importance in the decision of that controversy--the -carbon-theory and the theory of spontaneous generation. - -Physiological chemistry has, after countless analyses, established the -following five facts during the last forty years: - -I. No other elements are found in organic bodies than those of the -inorganic world. - -II. The combinations of elements which are peculiar to organisms, -and which are responsible for their vital phenomena, are compound -protoplasmic substances, of the group of albuminates. - -III. Organic life itself is a chemico-physical process, based on the -metabolism (or interchange of material) of these albuminates. - -IV. The only element which is capable of building up these compound -albuminates, in combination with other elements (oxygen, hydrogen, -nitrogen, and sulphur), is carbon. - -V. These protoplasmic compounds of carbon are distinguished from -most other chemical combinations by their very intricate molecular -structure, their instability, and their jelly-like consistency. - -On the basis of these five fundamental facts the following -"carbon-theory" was erected thirty-three years ago: "The peculiar -chemico-physical properties of carbon--especially the fluidity and -the facility of decomposition of the most elaborate albuminoid -compounds of carbon--are the sole and the mechanical causes of -the specific phenomena of movement, which distinguish organic from -inorganic substances, and which are called life, in the usual sense -of the word" (see _The Natural History of Creation_). Although this -"carbon-theory" is warmly disputed in some quarters, no better monistic -theory has yet appeared to replace it. We have now a much better and -more thorough knowledge of the physiological relations of cell-life, -and of the chemistry and physics of the living protoplasm, than we had -thirty-three years ago, and so it is possible to make a more confident -and effective defence of the carbon-theory. - -The old idea of spontaneous generation is now taken in many different -senses. It is owing to this indistinctness of the idea, and its -application to so many different hypotheses, that the problem is one -of the most contentious and confused of the science of the day. I -restrict the idea of spontaneous generation--also called abiogenesis -or archigony--to the first development of living protoplasm out of -inorganic carbonates, and distinguish two phases in this "beginning -of biogenesis": (1) _autogony_, or the rise of the simplest -protoplasmic substances in a formative fluid, and (2) _plasmogony_, -the differentiation of individual primitive organisms out of these -protoplasmic compounds, in the form of _monera_. I have treated this -important, though difficult, problem so exhaustively in the fifteenth -chapter of my _Natural History of Creation_ that I may content myself -here with referring to it. There is also a very searching and severely -scientific inquiry into it in my _General Morphology_ (1866). Naegeli -has also treated the hypothesis in quite the same sense in his -mechanico-physiological theory of descent (1884), and has represented -it to be an indispensable thesis in any natural theory of evolution. -I entirely agree with his assertion that "to reject abiogenesis is to -admit a miracle." - -The hypothesis of spontaneous generation and the allied carbon-theory -are of great importance in deciding the long-standing conflict between -the _teleological_ (dualistic) and the _mechanical_ (monistic) -interpretation of phenomena. Since Darwin gave us the key to the -monistic explanation of organization in his theory of selection forty -years ago, it has become possible for us to trace the splendid variety -of orderly tendencies of the organic world to mechanical, natural -causes, just as we could formerly in the inorganic world alone. Hence -the supernatural and telic forces, to which the scientist had had -recourse, have been rendered superfluous. Modern metaphysics, however, -continues to regard the latter as indispensable and the former as -inadequate. - -No philosopher has done more than Immanuel Kant in defining the -profound distinction between efficient and final causes, with relation -to the interpretation of the whole cosmos. In his well-known earlier -work on _The General Natural History and Theory of the Heavens_ he -made a bold attempt "to treat the constitution and the mechanical -origin of the entire fabric of the universe according to Newtonian -laws." This "cosmological nebular theory" was based entirely on the -mechanical phenomena of gravitation. It was expanded and mathematically -established later on by Laplace. When the famous French astronomer -was asked by Napoleon I. where God, the creator and sustainer of all -things, came in in his system, he clearly and honestly replied: "Sire, -I have managed without that hypothesis." That indicated the atheistic -character which this mechanical cosmogony shares with all the other -inorganic sciences. This is the more noteworthy because the theory of -Kant and Laplace is now almost universally accepted; every attempt to -supersede it has failed. When atheism is denounced as a grave reproach, -as it so often is, it is well to remember that the reproach extends to -the whole of modern science, in so far as it gives a purely mechanical -interpretation of the inorganic world. - -Mechanicism (in the Kantian sense) alone can give us a true explanation -of natural phenomena, for it traces them to their real efficient -causes, to blind and unconscious agencies, which are determined in -their action only by the material constitution of the bodies we are -investigating. Kant himself emphatically affirms that "there can be -no science without this mechanicism of nature," and that the capacity -of human reason to give a mechanical interpretation of phenomena is -unlimited. But when he came subsequently to give an elucidation of -the complex phenomena of organic nature in his _critique_ of the -teleological system, he declared that these mechanical causes were -inadequate; that in this we must call _final causes_ to our assistance. -It is true, he said, that even here we must recognize the theoretical -faculty of the mind to give a mechanical interpretation, but its actual -competence to do so is restricted. He grants it this capacity to some -extent; but for the majority of the vital processes (and especially for -man's psychic activity) he thinks we are bound to postulate _final_ -causes. The remarkable §79 of the _critique_ of judgment bears the -characteristic heading: "On the Necessity for the Subordination of -the Mechanical Principle to the Teleological in the Explanation of a -Thing as a Natural End." It seemed to Kant so impossible to explain -the orderly processes in the living organism without postulating -supernatural final causes (that is, a purposive creative force) that -he said: "It is quite certain that we cannot even satisfactorily -understand, much less elucidate, the nature of an organism and its -internal faculty on purely mechanical natural principles; it is so -certain, indeed, that we may confidently say, 'It is absurd for a man -to conceive the idea even that some day a Newton will arise who can -explain the origin of a single blade of grass by natural laws which are -uncontrolled by design'--such a hope is entirely forbidden us." Seventy -years afterwards this impossible "Newton of the organic world" appeared -in the person of Charles Darwin, and achieved the great task that Kant -had deemed impracticable. - -Since Newton (1682) formulated the law of gravitation, and Kant (1755) -established "the constitution and mechanical origin of the entire -fabric of the world on Newtonian laws," and Laplace (1796) provided -a mathematical foundation for this law of cosmic mechanicism, the -whole of the inorganic sciences have become purely _mechanical_, and -at the same time purely _atheistic_. Astronomy, cosmogony, geology, -meteorology, and inorganic physics and chemistry are now absolutely -ruled by mechanical laws on a mathematical foundation. The idea of -"design" has wholly disappeared from this vast province of science. -At the close of the nineteenth century, now that this monistic view -has fought its way to general recognition, no scientist ever asks -seriously of the "purpose" of any single phenomenon in the whole of -this great field. Is any astronomer likely to inquire seriously to-day -into the purpose of planetary motion, or a mineralogist to seek design -in the structure of a crystal? Does the physicist investigate the -purpose of electric force, or the chemist that of atomic weight? We -may confidently answer in the negative--certainly not, in the sense -that God, or a purposive natural force, had at some time created these -fundamental laws of the mechanism of the universe with a definite -design, and causes them to work daily in accordance with his rational -will. The anthropomorphic notion of a deliberate architect and ruler of -the world has gone forever from this field; the "eternal, iron laws of -nature" have taken his place. - -But the idea of design has a very great significance and application -in the _organic_ world. We do undeniably perceive a purpose in the -structure and in the life of an organism. The plant and the animal -seem to be controlled by a definite design in the combination of their -several parts, just as clearly as we see in the machines which man -invents and constructs; as long as life continues the functions of the -several organs are directed to definite ends, just as is the operation -of the various parts of a machine. Hence it was quite natural that the -older naïve study of nature, in explaining the origin and activity -of the living being, should postulate a creator who had "arranged -all things with wisdom and understanding," and had constructed each -plant and animal according to the special purpose of its life. The -conception of this "almighty creator of heaven and earth" was usually -quite anthropomorphic; he created "everything after its kind." As long -as the creator seemed to man to be of human shape, to think with his -brain, see with his eyes, and fashion with his hands, it was possible -to form a definite picture of this "divine engineer" and his artistic -work in the great workshop of creation. This was not so easy when -the idea of God became refined, and man saw in his "invisible God" a -creator without organs--a gaseous being. Still more unintelligible -did these anthropomorphic ideas become when physiology substituted -for the conscious, divine architect an unconscious, creative "vital -force"--a mysterious, purposive, natural force, which differed from the -familiar forces of physics and chemistry, and only took these in part, -during life, into its service. This vitalism prevailed until about the -middle of the nineteenth century. Johannes Müller, the great Berlin -physiologist, was the first to menace it with a destructive dose of -facts. It is true that the distinguished biologist had himself (like -all others in the first half of the century) been educated in a belief -in this vital force, and deemed it indispensable for an elucidation of -the ultimate sources of life; nevertheless, in his classical and still -unrivalled _Manual of Physiology_ (1833) he gave a demonstrative proof -that there is really nothing to be said for this vital force. Müller -himself, in a long series of remarkable observations and experiments, -showed that most of the vital processes in the human organism (and in -the other animals) take place according to physical and chemical laws, -and that many of them are capable of mathematical determination. That -was no less true of the animal functions of the muscles and nerves, -and of both the higher and the lower sense-organs, than of the vegetal -functions of digestion, assimilation, and circulation. Only two -branches of the life of the organism, mental action and reproduction, -retained any element of mystery, and seemed inexplicable without -assuming a vital force. But immediately after Müller's death such -important discoveries and advances were made in these two branches -that the uneasy "phantom of vital force" was driven from its last -refuge. By a very remarkable coincidence Johannes Müller died in the -year 1858, which saw the publication of Darwin's first communication -concerning his famous theory. The theory of selection solved the great -problem that had mastered Müller--the question of the origin of orderly -arrangements from purely mechanical causes. - -Darwin, as we have often said, had a twofold immortal merit in the -field of philosophy--firstly, the reform of Lamarck's theory of -descent, and its establishment on the mass of facts accumulated in the -course of the half-century; secondly, the conception of the theory -of selection, which first revealed to us the true causes of the -gradual formation of species. Darwin was the first to point out that -the "struggle for life" is the unconscious regulator which controls -the reciprocal action of heredity and adaptation in the gradual -transformation of species; it is the great "selective divinity" which, -by a purely "natural choice," without preconceived design, creates -new forms, just as selective man creates new types by an "artificial -choice" with a definite design. That gave us the solution of the great -philosophic problem: "How can purposive contrivances be produced by -purely mechanical processes without design?" Kant held the problem to -be insoluble, although Empedocles had pointed out the direction of the -solution two thousand years before. His principle of "teleological -mechanism" has become more and more accepted of late years, and -has furnished a mechanical explanation even of the finest and most -recondite processes of organic life by "the functional self-production -of the purposive structure." Thus have we got rid of the transcendental -"design" of the ideological philosophy of the schools, which was the -greatest obstacle to the growth of a rational and monistic conception -of nature. - -Very recently, however, this ancient phantom of a mystic vital force, -which seemed to be effectually banished, has put in a fresh appearance; -a number of distinguished biologists have attempted to reintroduce it -under another name. The clearest presentation of it is to be found in -the _Welt als That_, of the Kiel botanist, J. Reinke. He takes upon -himself the defence of the notion of miracle, of theism, of the Mosaic -story of creation, and of the constancy of species; he calls "vital -forces," in opposition to physical forces, the directive or dominant -forces. Other neovitalists prefer, in the good old anthropomorphic -style, a "supreme" engineer, who has endowed organic substance with a -purposive structure, directed to the realization of a definite plan. -These curious teleological hypotheses, and the objections to Darwinism -which generally accompany them, do not call for serious scientific -refutation to-day. - -Thirty-three years ago I gave the title of "dysteleology" to the -science of those extremely interesting and significant biological -facts, which, in the most striking fashion, give a direct contradiction -to the teleological idea "of the purposive arrangement of the living -organism."[30] This "science of rudimentary, abortive, arrested, -distorted, atrophied, and cataplastic individuals" is based on an -immense quantity of remarkable phenomena, which were long familiar to -zoologists and botanists, but were not properly interpreted, and their -great philosophic significance appreciated, until Darwin. - -All the higher animals and plants, or, in general, all organisms which -are not entirely simple in structure, but are made up of a number of -organs in orderly co-operation, are found, on close examination, to -possess a number of useless or inoperative members, sometimes, indeed, -hurtful and dangerous. In the flowers of most plants we find, besides -the actual sex-leaves that effect reproduction, a number of other -leaf-organs which have no use or meaning (arrested or "miscarried" -pistils, fruit, corona, and calix-leaves, etc.). In the two large and -variegated classes of flying animals, birds and insects, there are, -besides the forms which make constant use of their wings, a number of -species which have undeveloped wings and cannot fly. In nearly every -class of the higher animals which have eyes there are certain types -that live in the dark; they have eyes, as a rule, but undeveloped and -useless for vision. In our own human organism we have similar useless -rudimentary structures in the muscles of the ear, in the eye-lid, in -the nipple and milk-gland of the male, and in other parts of the body; -indeed, the vermiform appendix of our cæcum is not only useless, but -extremely dangerous, and inflammation of it is responsible for a number -of deaths every year. - -Neither the old mystic vitalism nor the new, equally irrational, -neovitalism can give any explanation of these and many other -purposeless contrivances in the structure of the plant and the animal; -but they are very simple in the light of the theory of descent. It -shows that these rudimentary organs are atrophied, owing to disuse. -Just as our muscles, nerves, and organs of sense are strengthened by -exercise and frequent use, so, on the other hand, they are liable to -degenerate more or less by disuse or suspended exercise. But, although -the development of the organs is promoted by exercise and adaptation, -they by no means disappear without leaving a trace after neglect; the -force of heredity retains them for many generations, and only permits -their gradual disappearance after the lapse of a considerable time. -The blind "struggle for existence between the organs" determines their -historical disappearance, just as it effected their first origin and -development. There is no internal "purpose" whatever in the drama. - -The life of the animal and the plant bears the same universal character -of incompleteness as the life of man. This is directly attributable -to the circumstance that nature--organic as well as inorganic--is -in a perennial state of evolution, change, and transformation. This -evolution seems on the whole--at least as far as we can survey the -development of organic life on our planet--to be a progressive -improvement, an historical advance from the simple to the complex, -the lower to the higher, the imperfect to the perfect. I have proved -in my _General Morphology_ that this historical progress--or gradual -perfecting (_teleosis_)--is the inevitable result of selection, and not -the outcome of a preconceived design. That is clear from the fact that -no organism is perfect; even if it does perfectly adapt itself to its -environment at a given moment, this condition would not last very long; -the conditions of existence of the environment are themselves subject -to perpetual change and they thus necessitate a continuous adaptation -on the part of the organism. - -Under the title of _Design in the Living Organism_, the famous -embryologist, Karl Ernst Baer, published a work in 1876 which, together -with the article on Darwinism which accompanied it, proved very -acceptable to our opponents, and is still much quoted in opposition -to evolution. It was a revival of the old teleological system under -a new name, and we must devote a line of criticism to it. We must -premise that, though Baer was a scientist of the highest order, his -original monistic views were gradually marred by a tinge of mysticism -with the advance of age, and he eventually became a thorough dualist. -In his profound work on "the evolution of animals" (1828), which he -himself entitled _Observation and Experiment_, these two methods of -investigation are equally applied. By careful observation of the -various phenomena of the development of the animal ovum Baer succeeded -in giving the first consistent presentation of the remarkable changes -which take place in the growth of the vertebrate from a simple -egg-cell. At the same time he endeavored, by far-seeing comparison -and keen reflection, to learn the causes of the transformation, and -to reduce them to general constructive laws. He expressed the general -result of his research in the following thesis: "The evolution of -the individual is the story of the growth of individuality in every -respect." He meant that "the one great thought that controls all the -different aspects of animal evolution is the same that gathered the -scattered fragments of space into spheres and linked them into solar -systems. This thought is no other than life itself, and the words and -syllables in which it finds utterance are the varied forms of living -things." - -Baer, however, did not attain to a deeper knowledge of this great -genetic truth and a clearer insight into the real efficient causes of -organic evolution, because his attention was exclusively given to -one half of evolutionary science, the science of the evolution of the -individual, embryology, or, in a wider sense, _ontogeny_. The other -half, the science of the evolution of species, _phylogeny_, was not yet -in existence, although Lamarck had already pointed out the way to it in -1809. When it was established by Darwin in 1859, the aged Baer was no -longer in a position to appreciate it; the fruitless struggle which he -led against the theory of selection clearly proved that he understood -neither its real meaning nor its philosophic importance. Teleological -and, subsequently, theological speculations had incapacitated the -ageing scientist from appreciating this greatest reform of biology. The -teleological observations which he published against it in his _Species -and Studies_ in his eighty-fourth year are mere repetitions of errors -which the teleology of the dualists has opposed to the mechanical or -monistic system for more than two thousand years. The "telic idea" -which, according to Baer, controls the entire evolution of the animal -from the ovum, is only another expression for the eternal "idea" of -Plato and the _entelecheia_ of his pupil Aristotle. - -Our modern biogeny gives a purely physiological explanation of the -facts of embryology, in assigning the functions of heredity and -adaptation as their causes. The great biogenetic law, which Baer -failed to appreciate, reveals the intimate causal connection between -the _ontogenesis_ of the individual and the _phylogenesis_ of its -ancestors; the former seems to be a recapitulation of the latter. -Nowhere, however, in the evolution of animals and plants do we find any -trace of design, but merely the inevitable outcome of the struggle for -existence, the blind controller, instead of the provident God, that -effects the changes of organic forms by a mutual action of the laws of -heredity and adaptation. And there is no more trace of "design" in the -embryology of the individual plant, animal, or man. This _ontogeny_ -is but a brief epitome of _phylogeny_, an abbreviated and condensed -recapitulation of it, determined by the physiological laws of heredity. - -Baer ended the preface to his classical _Evolution of Animals_ (1828) -with these words: "The palm will be awarded to the fortunate scientist -who succeeds in reducing the constructive forces of the animal body -to the general forces or life-processes of the entire world. The tree -has not yet been planted which is to make his cradle." The great -embryologist erred once more. That very year, 1828, witnessed the -arrival of Charles Darwin at Cambridge University (for the purpose of -studying theology!)--the "fortunate scientist" who richly earned the -palm thirty years afterwards by his theory of selection. - -In the philosophy of history--that is, in the general reflections which -historians make on the destinies of nations and the complicated course -of political evolution--there still prevails the notion of a "moral -order of the universe." Historians seek in the vivid drama of history -a leading design, an ideal purpose, which has ordained one or other -race or state to a special triumph, and to dominion over the others. -This teleological view of history has recently become more strongly -contrasted with our monistic view in proportion as monism has proved -to be the only possible interpretation of inorganic nature. Throughout -the whole of astronomy, geology, physics, and chemistry there is no -question to-day of a "moral order," or a personal God, whose "hand hath -disposed all things in wisdom and understanding." And the same must -be said of the entire field of biology, the whole constitution and -history of organic nature, if we set aside the question of man for the -moment. Darwin has not only proved by his theory of selection that the -orderly processes in the life and structure of animals and plants have -arisen by mechanical laws without any preconceived design, but he has -shown us in the "struggle for life" the powerful natural force which -has exerted supreme control over the entire course of organic evolution -for millions of years. It may be said that the struggle for life is the -"survival of the fittest" or the "victory of the best"; that is only -correct when we regard the strongest as the best (in a moral sense). -Moreover, the whole history of the organic world goes to prove that, -besides the predominant advance towards perfection, there are at all -times cases of retrogression to lower stages. Even Baer's notion of -"design" has no moral feature whatever. - -Do we find a different state of things in the history of peoples, which -man, in his anthropocentric presumption, loves to call "the history of -the world"? Do we find in every phase of it a lofty moral principle or -a wise ruler, guiding the destinies of nations? There can be but one -answer in the present advanced stage of natural and human history: No. -The fate of those branches of the human family, those nations and races -which have struggled for existence and progress for thousands of years, -is determined by the same "eternal laws of iron" as the history of the -whole organic world which has peopled the earth for millions of years. - -Geologists distinguish three great epochs in the organic history of -the earth, as far as we can read it in the monuments of the science of -fossils--the primary, secondary, and tertiary epochs. According to a -recent calculation, the first occupied at least thirty-four million, -the second eleven million, and the third three million years. The -history of the family of vertebrates, from which our own race has -sprung, unfolds clearly before our eyes during this long period. Three -different stages in the evolution of the vertebrate correspond to the -three epochs; the _fishes_ characterized the primary (palæozoic) age, -the _reptiles_ the secondary (mesozoic), and the _mammals_ the tertiary -(cænozoic). Of the three groups the fishes rank lowest in organization, -the reptiles come next, and the mammals take the highest place. We -find, on nearer examination of the history of the three classes, that -their various orders and families also advanced progressively during -the three epochs towards a higher stage of perfection. May we consider -this progressive development as the outcome of a conscious design or -a moral order of the universe? Certainly not. The theory of selection -teaches us that this organic progress, like the earlier organic -differentiation, is an inevitable consequence of the struggle for -existence. Thousands of beautiful and remarkable species of animals and -plants have perished during those forty-eight million years, to give -place to stronger competitors, and the victors in this struggle for -life were not always the noblest or most perfect forms in a moral sense. - -It has been just the same with the history of humanity. The splendid -civilization of classical antiquity perished because Christianity, -with its faith in a loving God and its hope of a better life beyond -the grave, gave a fresh, strong impetus to the soaring human mind. The -Papal Church quickly degenerated into a pitiful caricature of real -Christianity, and ruthlessly scattered the treasures of knowledge -which the Hellenic philosophy had gathered; it gained the dominion -of the world through the ignorance of the credulous masses. In time -the Reformation broke the chains of this mental slavery, and assisted -reason to secure its right once more. But in the new, as in the -older, period the great struggle for existence went on in its eternal -fluctuation, with no trace of a moral order. - -And it is just as impossible for the impartial and critical observer -to detect a "wise providence" in the fate of individual human beings -as a moral order in the history of peoples. Both are determined with -iron necessity by a mechanical causality which connects every single -phenomenon with one or more antecedent causes. Even the ancient Greeks -recognized _ananke_, the blind _heimarmene_, the fate "that rules -gods and men," as the supreme principle of the universe. Christianity -replaced it by a conscious Providence, which is not blind, but sees, -and which governs the world in patriarchal fashion. The anthropomorphic -character of this notion, generally closely connected with belief in -a personal God, is quite obvious. Belief in a "loving Father," who -unceasingly guides the destinies of one billion five hundred million -men on our planet, and is attentive at all times to their millions of -contradictory prayers and pious wishes, is absolutely impossible; that -is at once perceived on laying aside the colored spectacles of "faith" -and reflecting rationally on the subject. - -As a rule, this belief in Providence and the tutelage of a "loving -Father" is more intense in the modern civilized man--just as in the -uncultured savage--when some good fortune has fallen him: an escape -from peril of life, recovery from a severe illness, the winning of the -first prize in a lottery, the birth of a long-delayed child, and so -forth. When, on the other hand, a misfortune is met with, or an ardent -wish is not fulfilled, "Providence" is forgotten. The wise ruler of the -world slumbered--or refused his blessing. - -In the extraordinary development of commerce of the nineteenth century -the number of catastrophes and accidents has necessarily increased -beyond all imagination; of that the journal is a daily witness. -Thousands are killed every year by shipwreck, railway accidents, mine -accidents, etc. Thousands slay each other every year in war, and the -preparation for this wholesale massacre absorbs much the greater part -of the revenue in the highest civilized nations, the chief professors -of "Christian charity." And among these hundreds of thousands of annual -victims of modern civilization strong, industrious, courageous workers -predominate. Yet the talk of a "moral order" goes on. - -Since impartial study of the evolution of the world teaches us that -there is no definite aim and no special purpose to be traced in it, -there seems to be no alternative but to leave everything to "blind -chance." This reproach has been made to the transformism of Lamarck and -Darwin, as it had been to the previous systems of Kant and Laplace; -there are a number of dualist philosophers who lay great stress on it. -It is, therefore, worth while to make a brief remark upon it. - -One group of philosophers affirms, in accordance with its teleological -conception, that the whole cosmos is an orderly system, in which every -phenomenon has its aim and purpose; there is no such thing as chance. -The other group, holding a mechanical theory, expresses itself thus: -The development of the universe is a monistic mechanical process, in -which we discover no aim or purpose whatever; what we call design in -the organic world is a special result of biological agencies; neither -in the evolution of the heavenly bodies nor in that of the crust of -our earth do we find any trace of a controlling purpose--all is the -result of chance. Each party is right--according to its definition of -chance. The general law of causality, taken in conjunction with the law -of substance, teaches us that every phenomenon has a mechanical cause; -in this sense there is no such thing as chance. Yet it is not only -lawful, but necessary, to retain the term for the purpose of expressing -the simultaneous occurrence of two phenomena, which are not causally -related to each other, but of which each has its own mechanical cause, -independent of that of the other. Everybody knows that chance, in its -monistic sense, plays an important part in the life of man and in the -universe at large. That, however, does not prevent us from recognizing -in each "chance" event, as we do in the evolution of the entire -cosmos, the universal sovereignty of nature's supreme law, _the law of -substance_. - - - - -CHAPTER XV - -GOD AND THE WORLD - - The Idea of God in General--Antithesis of God and the World; the - Supernatural and Nature--Theism and Pantheism--Chief Forms of - Theism--Polytheism--Triplotheism--Amphitheism--Monotheism--Religious - Statistics--Naturalistic Monotheism--Solarism--Anthropistic - Monotheism--The Three Great Mediterranean - Religions--Mosaism--Christianity--The Cult of the Madonna and - the Saints--Papal Polytheism--Islam--Mixotheism--Nature of - Theism--An Extra-mundane and Anthropomorphic God; a Gaseous - Vertebrate--Pantheism--Intramundane God (Nature)--The Hylozoism - of the Ionic Monists (Anaximander)--Conflict of Pantheism and - Christianity--Spinoza--Modern Monism--Atheism - - -For thousands of years humanity has placed the last and supreme basis -of all phenomena in an efficient cause, to which it gives the title of -God (_deus_, _theos_). Like all general ideas, this notion of God has -undergone a series of remarkable modifications and transformations in -the course of the evolution of reason. Indeed, it may be said that no -other idea has had so many metamorphoses; for no other belief affects -in so high a degree the chief objects of the mind and of rational -science, as well as the deepest interests of the emotion and poetic -fancy of the believer. - -A comparative criticism of the many different forms of the idea of God -would be extremely interesting and instructive; but we have not space -for it in the present work. We must be content with a passing glance -at the most important forms of the belief and their relation to the -modern thought that has been evoked by a sound study of nature. For -further information on this interesting question the reader would do -well to consult the distinguished work of Adalbert Svoboda, _Forms of -Faith_ (1897). - -When we pass over the finer shades and the variegated clothing of -the God-idea and confine our attention to its chief element, we can -distribute all the different presentations of it in two groups--the -_theistic_ and _pantheistic_ group. The latter is closely connected -with the monistic, or rational, view of things, and the former is -associated with dualism and mysticism. - - -I.--THEISM - -In this view God is distinct from, and opposed to, the world as its -creator, sustainer, and ruler. He is always conceived in a more or -less human form, as an organism which thinks and acts like a man--only -on a much higher scale. This anthropomorphic God, polyphyletically -evolved by the different races, assumes an infinity of shapes in their -imagination, from fetichism to the refined monotheistic religions -of the present day. The chief forms of theism are polytheism, -triplotheism, amphitheism, and monotheism. - -The polytheist peoples the world with a variety of gods and goddesses, -which enter into its machinery more or less independently. _Fetichism_ -sees such subordinate deities in the lifeless body of nature, in rocks, -in water, in the air, in human productions of every kind (pictures, -statues, etc.). _Demonism_ sees gods in living organisms of every -species--trees, animals, and men. This kind of polytheism is found in -innumerable forms even in the lowest tribes. It reaches the highest -stage in Hellenic polytheism, in the myths of ancient Greece, which -still furnish the finest images to the modern poet and artist. At a -much lower stage we have Catholic polytheism, in which innumerable -"saints" (many of them of very equivocal repute) are venerated as -subordinate divinities, and prayed to to exert their mediation with the -supreme divinity. - -The dogma of the "Trinity," which still comprises three of the chief -articles of faith in the creed of Christian peoples, culminates in the -notion that the one God of Christianity is really made up of _three_ -different persons: (1) God the Father, the omnipotent creator of heaven -and earth (this untenable myth was refuted long ago by scientific -cosmogony, astronomy, and geology); (2) Jesus Christ; and (3) the Holy -Ghost, a mystical being, over whose incomprehensible relation to the -Father and the Son millions of Christian theologians have racked their -brains in vain for the last nineteen hundred years. The Gospels, which -are the only clear sources of this _triplotheism_, are very obscure as -to the relation of these three persons to each other, and do not give a -satisfactory answer to the question of their unity. On the other hand, -it must be carefully noted what confusion this obscure and mystic dogma -of the Trinity must necessarily cause in the minds of our children even -in the earlier years of instruction. One morning they learn (in their -religious instruction) that three times one are one, and the very next -hour they are told in their arithmetic class that three times one are -three. I remember well the reflection that this confusion led me to in -my early school-days. - -For the rest, the "Trinity" is not an original element in Christianity; -like most of the other Christian dogmas, it has been borrowed from -earlier religions. Out of the sun-worship of the Chaldean magi was -evolved the Trinity of Ilu, the mysterious source of the world; its -three manifestations were Anu, primeval chaos; Bel, the architect of -the world; and Aa, the heavenly light, the all-enlightening wisdom. -In the Brahmanic religion the Trimurti is also conceived as a "divine -unity" made up of three persons--Brahma (the creator), Vishnu (the -sustainer), and Shiva (the destroyer). It would seem that in this -and other ideas of a Trinity the "sacred number, three," as such--as -a "symbolical number"--has counted for something. The three first -Christian virtues--Faith, Hope, and Charity--form a similar _triad_. - -According to the _amphitheists_, the world is ruled by two different -gods, a good and an evil principle, God and the Devil. They are engaged -in a perpetual struggle, like rival emperors, or pope and anti-pope. -The condition of the world is the result of this conflict. The -loving God, or good principle, is the source of all that is good and -beautiful, of joy and of peace. The world would be perfect if His work -were not continually thwarted by the evil principle, the Devil; this -being is the cause of all that is bad and hateful, of contradiction and -of pain. - -Amphitheism is undoubtedly the most rational of all forms of belief in -God, and the one which is least incompatible with a scientific view -of the world. Hence we find it elaborated in many ancient peoples -thousands of years before Christ. In ancient India Vishnu, the -preserver, struggles with Shiva, the destroyer. In ancient Egypt the -good Osiris is opposed by the wicked Typhon. The early Hebrews had a -similar dualism of Aschera (or Keturah), the fertile mother-earth, -and Elion (Moloch or Sethos), the stern heavenly father. In the Zend -religion of the ancient Persians, founded by Zoroaster two thousand -years before Christ, there is a perpetual struggle between Ormuzd, the -good god of light, and Ahriman, the wicked god of darkness. - -In Christian mythology the Devil is scarcely less conspicuous as the -adversary of the good deity, the tempter and seducer, the prince of -hell, and lord of darkness. A personal devil was still an important -element in the belief of most Christians at the beginning of the -nineteenth century. Towards the middle of the century he was gradually -eliminated by being progressively explained away, or he was restricted -to the subordinate _rôle_ he plays as Mephistopheles in Goethe's great -drama. To-day the majority of educated people look upon "belief in a -personal devil" as a mediæval superstition, while "belief in God" (that -is, the personal, good, and loving God) is retained as an indispensable -element of religion. Yet the one belief is just as much (or as little) -justified as the other. In any case, the much-lamented "imperfection of -our earthly life," the "struggle for existence," and all that pertains -to it, are explained much more simply and naturally by this struggle of -a good and an evil god than by any other form of theism. - -The dogma of the unity of God may in some respects be regarded as the -simplest and most natural type of theism; it is popularly supposed to -be the most widely accepted element of religion, and to predominate -in the ecclesiastical systems of civilized countries. In reality, -that is not the case, because this alleged "monotheism" usually turns -out on closer inquiry to be one of the other forms of theism we have -examined, a number of subordinate deities being generally introduced -besides the supreme one. Most of the religions which took a purely -monotheistic stand-point have become more or less polytheistic in the -course of time. Modern statistics assure us that of the one billion -five hundred million men who people the earth the great majority -are monotheists; of these, _nominally_, about six hundred millions -are Brahma-Buddhists, five hundred millions are called Christians, -two hundred millions are heathens (of various types), one hundred -and eighty millions are Mohammedans, ten millions are Jews, and ten -millions have no religion at all. However, the vast majority of -these nominal monotheists have very confused ideas about the deity, -or believe in a number of gods and goddesses besides the chief -god--angels, devils, etc. - -The different forms which monotheism has assumed in the course of its -polyphyletic development may be distributed in two groups--those of -_naturalistic_ and _anthropistic_ monotheism. Naturalistic monotheism -finds the embodiment of the deity in some lofty and dominating natural -phenomenon. The sun, the deity of light and warmth, on whose influence -all organic life insensibly and directly depends, was taken to be -such a phenomenon many thousand years ago. Sun-worship (solarism, -or heliotheism) seems to the modern scientist to be the best of all -forms of theism, and the one which may be most easily reconciled -with modern monism. For modern astrophysics and geogeny have taught -us that the earth is a fragment detached from the sun, and that it -will eventually return to the bosom of its parent. Modern physiology -teaches us that the first source of organic life on the earth is the -formation of protoplasm, and that this synthesis of simple inorganic -substances, water, carbonic acid, and ammonia, only takes place under -the influence of sunlight. On the primary evolution of the plasmodomous -plants followed, secondarily, that of the plasmophagous animals, which -directly or indirectly depend on them for nourishment; and the origin -of the human race itself is only a later stage in the development of -the animal kingdom. Indeed, the whole of our bodily and mental life -depends, in the last resort, like all other organic life, on the -light and heat rays of the sun. Hence in the light of pure reason, -sun-worship, as a form of naturalistic monotheism, seems to have a much -better foundation than the anthropistic worship of Christians and of -other monotheists who conceive their god in human form. As a matter of -fact, the sun-worshippers attained, thousands of years ago, a higher -intellectual and moral standard than most of the other theists. When -I was in Bombay, in 1881, I watched with the greatest sympathy the -elevating rites of the pious Parsees, who, standing on the sea-shore, -or kneeling on their prayer-rugs, offered their devotion to the sun at -its rise and setting.[31] - -Moon-worship (lunarism and selenotheism) is of much less importance -than sun-worship. There are a few uncivilized races that have adored -the moon as their only deity, but it has generally been associated with -a worship of the stars and the sun. - -The humanization of God, or the idea that the "Supreme Being" feels, -thinks, and acts like man (though in a higher degree), has played a -most important part, as _anthropomorphic monotheism_, in the history -of civilization. The most prominent in this respect are the three -great religions of the Mediterranean peoples--the old Mosaic religion, -the intermediate Christian religion, and the younger Mohammedanism. -These three great Mediterranean religions, all three arising on the -east coast of the most interesting of all seas, and originating in an -imaginative enthusiast of the Semitic race, are intimately connected, -not only by this external circumstance of an analogous origin, but by -many common features of their internal contents. Just as Christianity -borrowed a good deal of its mythology directly from ancient Judaism, so -Islam has inherited much from both its predecessors. All the three were -originally monotheistic; all three were subsequently overlaid with a -great variety of polytheistic features, in proportion as they extended, -first along the coast of the Mediterranean with its heterogeneous -population, and eventually into every part of the world. - -The Hebrew monotheism, as it was founded by Moses (about 1600 B.C.), is -usually regarded as the ancient faith which has been of the greatest -importance in the ethical and religious development of humanity. -This high historical appreciation is certainly valid in the sense -that the two other world-conquering Mediterranean religions issued -from it; Christ was just as truly a pupil of Moses as Mohammed was -afterwards of Christ. So also the New Testament, which has become the -foundation of the belief of the highest civilized nations in the short -space of nineteen hundred years, rests on the venerable basis of the -Old Testament. The Bible, which the two compose, has had a greater -influence and a wider circulation than any other book in the world. -Even to-day the Bible--in spite of its curious mingling of the best and -the worst elements--is in a certain sense the "book of books." Yet when -we make an impartial and unprejudiced study of this notable historical -source, we find it very different in several important respects from -the popular impression. Here again modern criticism and history have -come to certain conclusions which destroy the prevalent tradition in -its very foundations. - -The monotheism which Moses endeavored to establish in the worship -of Jehovah, and which the prophets--the philosophers of the Hebrew -race--afterwards developed with great success, had at first to sustain -a long and severe struggle with the dominant polytheism which was -in possession. Jehovah, or Yahveh, was originally derived from the -heaven-god, which, under the title of Moloch or Baal, was one of -the most popular of the Oriental deities (the Sethos or Typhon of -the Egyptians, and the Saturn or Cronos of the Greeks). There were, -however, other gods in great favor with the Jewish people, and so the -struggle with "idolatry" continued. Still, Jehovah was, in principle, -the only God, explicitly claiming, in the first precept of the -decalogue: "I am the Lord thy God; thou shalt have no other gods beside -me." - -Christian monotheism shared the fate of its mother, Mosaism; it was -generally only monotheistic in theory, while it degenerated practically -into every kind of polytheism. In point of fact, monotheism was -logically abandoned in the very dogma of the Trinity, which was adopted -as an indispensable foundation of the Christian religion. The three -persons, which are distinguished as Father, Son, and Holy Ghost, are -three distinct individuals (and, indeed, anthropomorphic persons), just -as truly as the three Indian deities of the Trimurti (Brahma, Vishnu, -and Shiva) or the Trinity of the ancient Hebrews (Anu, Bel, and Aa). -Moreover, in the most widely distributed form of Christianity the -"virgin" mother of Christ plays an important part as a fourth deity; -in many Catholic countries she is practically taken to be much more -powerful and influential than the three male persons of the celestial -administration. The cult of the madonna has been developed to such an -extent in these countries that we may oppose it to the usual masculine -form of monotheism as one of a feminine type. The "Queen of Heaven" -becomes so prominent, as is seen in so many pictures and legends of the -madonna, that the three male persons practically disappear. - -In addition, the imagination of the pious Christian soon came to -increase this celestial administration by a numerous company of -"saints" of all kinds, and bands of musical angels, who should see -that "eternal life" should not prove too dull. The popes--the greatest -charlatans that any religion ever produced--have constantly studied to -increase this band of celestial satellites by repeated canonizations. -This curious company received its most interesting acquisition in 1870, -when the Vatican Council pronounced the popes, as the vicars of Christ, -to be infallible, and thus raised them to a divine dignity. When we add -the "personal Devil" that they acknowledge, and the "bad angels" who -form his court, we have in modern Catholicism, still the most extensive -branch of Christianity, a rich and variegated polytheism that dwarfs -the Olympic family of the Greeks. - -Islam, or the Mohammedan monotheism, is the youngest and purest form of -monotheism. When the young Mohammed (born 570) learned to despise the -polytheistic idolatry of his Arabian compatriots, and became acquainted -with Nestorian Christianity, he adopted its chief doctrines in a -general way; but he could not bring himself to see anything more than -a prophet in Christ, like Moses. He found in the dogma of the Trinity -what every emancipated thinker finds on impartial reflection--an -absurd legend which is neither reconcilable with the first principles -of reason nor of any value whatever for our religious advancement. He -justly regarded the worship of the immaculate mother of God as a piece -of pure idolatry, like the veneration of pictures and images. The -longer he reflected on it, and the more he strove after a purified idea -of deity, the clearer did the certitude of his great maxim appear: "God -is the only God"--there are no other gods beside him. - -Yet Mohammed could not free himself from the anthropomorphism of the -God-idea. His one only God was an idealized, almighty man, like the -stern, vindictive God of Moses, and the gentle, loving God of Christ. -Still, we must admit that the Mohammedan religion has preserved the -character of pure monotheism throughout the course of its historical -development and its inevitable division much more faithfully than the -Mosaic and Christian religions. We see that to-day, even externally, -in its forms of prayer and preaching, and in the architecture and -adornment of its mosques. When I visited the East for the first time, -in 1873, and admired the noble mosques of Cairo, Smyrna, Brussa, and -Constantinople, I was inspired with a feeling of real devotion by the -simple and tasteful decoration of the interior, and the lofty and -beautiful architectural work of the exterior. How noble and inspiring -do these mosques appear in comparison with the majority of Catholic -churches, which are covered internally with gaudy pictures and gilt, -and are outwardly disfigured by an immoderate crowd of human and -animal figures! Not less elevated are the silent prayers and the -simple devotional acts of the Koran when compared with the loud, -unintelligible verbosity of the Catholic Mass and the blatant music of -their theatrical processions. - -Under the title of _mixotheism_ we may embrace all the forms of -theistic belief which contain mixtures of religious notions of -different, sometimes contradictory, kinds. In theory this most widely -diffused type of religion is not recognized at all; in the concrete -it is the most important and most notable of all. The vast majority -of men who have religious opinions have always been, and still are, -_mixotheists_; their idea of God is picturesquely compounded from the -impressions received in childhood from their own sect, and a number -of other impressions which are received later on, from contact with -members of other religions, and which modify the earlier notions. In -educated people there is also sometimes the modifying influence of -philosophic studies in maturer years, and especially the unprejudiced -study of natural phenomena, which reveals the futility of the theistic -idea. The conflict of these contradictory impressions, which is -very painful to a sensitive soul, and which often remains undecided -throughout life, clearly shows the immense power of the _heredity_ of -ancient myths on the one hand and the early _adaptation_ to erroneous -dogmas on the other. The particular faith in which the child has been -brought up generally remains in power, unless a "conversion" takes -place subsequently, owing to the stronger influence of some other -religion. But even in this supersession of one faith by another the new -name, like the old one, proves to be merely an outward label covering -a mixture of the most diverse opinions and errors. The greater part -of those who call themselves Christians are not monotheists (as they -think), but amphitheists, triplotheists, or polytheists. And the same -must be said of Islam and Mosaism, and other monotheistic religions. -Everywhere we find associated with the original idea of a "sole and -triune God" later beliefs in a number of subordinate deities--angels, -devils, saints, etc.--a picturesque assortment of the most diverse -theistic forms. - -All the above forms of theism, in the proper sense of the word--whether -the belief assumes a naturalistic or an anthropistic form--represent -God to be an extramundane or a supernatural being. He is always opposed -to the world, or nature, as an independent being; generally as its -creator, sustainer, and ruler. In most religions he has the additional -character of personality, or, to put it more definitely still, God as -a person is likened to man. "In his gods man paints himself." This -anthropomorphic conception of God as one who thinks, feels, and acts -like man prevails with the great majority of theists, sometimes in a -cruder and more naïve form, sometimes in a more refined and abstract -degree. In any case the form of theosophy we have described is sure -to affirm that God, the supreme being, is infinite in perfection, and -therefore far removed from the imperfection of humanity. Yet, when we -examine closely, we always find the same psychic or mental activity in -the two. God feels, thinks, and acts as man does, although it be in an -infinitely more perfect form. - -The _personal anthropism_ of God has become so natural to the majority -of believers that they experience no shock when they find God -personified in human form in pictures and statues, and in the varied -images of the poet, in which God takes human form--that is, is changed -into a vertebrate. In some myths, even, God takes the form of other -mammals (an ape, lion, bull, etc.), and more rarely of a bird (eagle, -dove, or stork), or of some lower vertebrate (serpent, crocodile, -dragon, etc.). - -In the higher and more abstract forms of religion this idea of bodily -appearance is entirely abandoned, and God is adored as a "pure spirit" -without a body. "God is a spirit, and they who worship him must worship -him in spirit and in truth." Nevertheless, the psychic activity of this -"pure spirit" remains just the same as that of the anthropomorphic -God. In reality, even this immaterial spirit is not conceived to be -incorporeal, but merely invisible, gaseous. We thus arrive at the -paradoxical conception of God as a _gaseous vertebrate_. - - -II.--PANTHEISM - -Pantheism teaches that God and the world are one. The idea of God is -identical with that of nature or substance. This pantheistic view is -sharply opposed in principle to all the systems we have described, and -to all possible forms of theism although there have been many attempts -made from both sides to bridge over the deep chasm that separates the -two. There is always this fundamental contradiction between them, that -in theism God is opposed to nature as an _extramundane_ being, as -creating and sustaining the world, and acting upon it from without, -while in pantheism God, as an _intramundane_ being, is everywhere -identical with nature itself, and is operative _within_ the world -as "force" or "energy." The latter view alone is compatible with -our supreme law--the law of substance. It follows necessarily that -pantheism is _the world-system of the modern scientist_. There are, -it is true, still a few men of science who contest this, and think it -possible to reconcile the old theistic theory of human nature with the -pantheistic truth of the law of substance. All these efforts rest on -confusion or sophistry--when they are honest. - -As pantheism is a result of an advanced conception of nature in the -civilized mind, it is naturally much younger than theism, the crudest -forms of which are found in great variety in the uncivilized races of -ten thousand years ago. We do, indeed, find the germs of pantheism in -different religions at the very dawn of philosophy in the earliest -civilized peoples (in India, Egypt, China, and Japan), several thousand -years before the time of Christ; still, we do not meet a definite -philosophical expression of it until the hylozoism of the Ionic -philosophers, in the first half of the sixth century before Christ. -All the great thinkers of this flourishing period of Hellenic thought -are surpassed by the famous Anaximander, of Miletus, who conceived the -essential unity of the infinite universe (_apeiron_) more profoundly -and more clearly than his master, Thales, or his pupil, Anaximenes. -Not only the great thought of the original unity of the cosmos and the -development of all phenomena out of the all-pervading primitive matter -found expression in Anaximander, but he even enunciated the bold idea -of countless worlds in a periodic alternation of birth and death. - -Many other great philosophers of classical antiquity, especially -Democritus, Heraclitus, and Empedocles, had, in the same or an -analogous sense, a profound conception of this unity of nature and -God, of body and spirit, which has obtained its highest expression -in the law of substance of our modern monism. The famous Roman poet -and philosopher, Lucretius Carus, has presented it in a highly poetic -form in his poem "De Rerum Natura." However, this true pantheistic -monism was soon entirely displaced by the mystic dualism of Plato, and -especially by the powerful influence which the idealistic philosophy -obtained by its blending with Christian dogmas. When the papacy -attained to its spiritual despotism over the world, pantheism was -hopelessly crushed; Giordano Bruno, its most gifted defender, was -burned alive by the "Vicar of Christ" in the Campo dei Fiori at Rome on -February 17, 1600. - -It was not until the middle of the seventeenth century that pantheism -was exhibited in its purest form by the great Baruch Spinoza; he gave -for the totality of things a definition of substance in which God -and the world are inseparably united. The clearness, confidence, and -consistency of Spinoza's monistic system are the more remarkable when -we remember that this gifted thinker of two hundred and fifty years -ago was without the support of all those sound empirical bases which -have been obtained in the second half of the nineteenth century. We -have already spoken, in the first chapter, of Spinoza's relation to the -materialism of the eighteenth and the monism of the nineteenth century. -The propagation of his views, especially in Germany, is due, above -all, to the immortal works of our greatest poet and thinker, Wolfgang -Goethe. His splendid _God and the World_, _Prometheus_, _Faust_, etc., -embody the great thoughts of pantheism in the most perfect poetic -creations. - -Atheism affirms that there are no gods or goddesses, assuming that -god means a personal, extramundane entity. This "godless world-system" -substantially agrees with the monism or pantheism of the modern -scientist; it is only another expression for it, emphasizing its -negative aspect, the non-existence of any supernatural deity. In this -sense Schopenhauer justly remarks: "Pantheism is only a polite form -of atheism. The truth of pantheism lies in its destruction of the -dualist antithesis of God and the world, in its recognition that the -world exists in virtue of its own inherent forces. The maxim of the -pantheist, 'God and the world are one,' is merely a polite way of -giving the Lord God his _congé_." - -During the whole of the Middle Ages, under the bloody despotism of the -popes, atheism was persecuted with fire and sword as a most pernicious -system. As the "godless" man is plainly identified with the "wicked" -in the Gospel, and is threatened--simply on account of his "want of -faith"--with the eternal fires of hell, it was very natural that every -good Christian should be anxious to avoid the suspicion of atheism. -Unfortunately, the idea still prevails very widely. The atheistic -scientist who devotes his strength and his life to the search for -the truth, is freely credited with all that is evil; the theistic -church-goer, who thoughtlessly follows the empty ceremonies of Catholic -worship, is at once assumed to be a good citizen, even if there be no -meaning whatever in his faith and his morality be deplorable. This -error will only be destroyed when, in the twentieth century, the -prevalent superstition gives place to rational knowledge and to a -monistic conception of the unity of God and the world. - - - - -CHAPTER XVI - -KNOWLEDGE AND BELIEF - - The Knowledge of the Truth and Its Sources: the Activity of the - Senses and the Association of Presentations--Organs of Sense and - Organs of Thought--Sense-Organs and their Specific Energy--Their - Evolution--The Philosophy of Sensibility--Inestimable Value of the - Senses--Limits of Sensitive Knowledge--Hypothesis and Faith--Theory - and Faith--Essential Difference of Scientific (Natural) and - Religious (Supernatural) Faith--Superstition of Savage and of - Civilized Races--Confessions of Faith--Unsectarian Schools--The - Faith of Our Fathers--Spiritism--Revelation - - -Every effort of genuine science makes for a knowledge of the truth. Our -only real and valuable knowledge is a knowledge of nature itself, and -consists of presentations which correspond to external things. We are -incompetent, it is true, to penetrate into the innermost nature of this -real world--the "thing in itself"--but impartial critical observation -and comparison inform us that, in the normal action of the brain and -the organs of sense, the impressions received by them from the outer -world are the same in all rational men, and that in the normal function -of the organs of thought certain presentations are formed which are -everywhere the same. These presentations we call _true_, and we are -convinced that their content corresponds to the knowable aspect of -things. We _know_ that these facts are not imaginary, but real. - -All knowledge of the truth depends on two different, but intimately -connected, groups of human physiological functions: firstly, on the -_sense-impressions_ of the object by means of sense-action, and, -secondly, on the combination of these impressions by an association -into _presentations_ in the subject. The instruments of sensation are -the sense-organs (_sensilla_ or _aestheta_); the instruments which -form and link together the presentations are the organs of thought -(_phroneta_). The latter are part of the central, and the former part -of the peripheral, nervous system--that important and elaborate system -of organs in the higher animals which alone effects their entire -psychic activity. - -Man's sense-activity, which is the starting-point of all knowledge, -has been slowly and gradually developed from that of his nearest -mammal relatives, the primates. The sense-organs are of substantially -the same construction throughout this highest animal group, and their -function takes place always according to the same physical and chemical -laws. They have had the same historical development in all cases. In -the mammals, as in the case of all other animals, the _sensilla_ were -originally parts of the skin; the sensitive cells of the epidermis are -the sources of all the different sense-organs, which have acquired -their specific energy by adaptation to different stimuli (light, heat, -sound, chemical action, etc.). The rod-cells in the retina of the eye, -the auditory cells in the cochlea of the ear, the olfactory cells in -the nose, and the taste-cells on the tongue, are all originally derived -from the simple, indifferent cells of the epidermis, which cover the -entire surface of the body. This significant fact can be directly -proved by observation of the embryonic development of man or any of the -higher animals. And from this ontogenetic fact we confidently infer, -in virtue of the great biogenetic law, the important phylogenetic -proposition, that in the long historical evolution of our ancestors, -likewise, the higher sense-organs with their specific energies were -originally derived from the epidermis of lower animals, from a simple -layer of cells which had no trace of such differentiated sensilla. - -A particular importance attaches to the circumstance that different -nerves are qualified to perceive different properties of the -environment, and these only. The optic nerve accomplishes only the -perception of light, the auditory nerve the perception of sound, the -olfactory nerve the perception of smell, and so on. No matter what -stimuli impinge on and irritate a given sense-organ, its reaction -is always of the same character. From this specific energy of the -sense-nerves, which was first fully appreciated by Johannes Müller, -very erroneous inferences have been drawn, especially in favor of a -dualistic and _à priori_ theory of knowledge. It has been affirmed -that the brain, or the soul, only perceives a certain condition of the -stimulated nerve, and that, consequently, no conclusion can be drawn -from the process as to the existence and nature of the stimulating -environment. Sceptical philosophy concluded that the very existence of -an outer world is doubtful, and extreme idealism went on positively to -deny it, contending that things only exist in our impressions of them. - -In opposition to these erroneous views, we must recall the fact that -the "specific energy" was not originally an innate, special quality of -the various nerves, but it has arisen by adaptation to the particular -activity of the epidermic cells in which they terminate. In harmony -with the great law of "division of labor" the originally indifferent -"sense-cells of the skin" undertook different tasks, one group of them -taking over the stimulus of the light rays, another the impress of the -sound waves, a third the chemical impulse of odorous substances, and so -on. In the course of a very long period these external stimuli effected -a gradual change in the physiological, and later in the morphological, -properties of these parts of the epidermis, and there was a correlative -modification of the sensitive nerves which conduct the impressions they -receive to the brain. Selection improved, step by step, such particular -modifications as proved to be useful, and thus eventually, in the -course of many million years, created those wonderful instruments, -the eye and the ear, which we prize so highly; their structure is -so remarkably purposive that they might well lead to the erroneous -assumption of a "creation on a preconceived design." The peculiar -character of each sense-organ and its specific nerve has thus been -gradually evolved by use and exercise--that is, by _adaptation_--and -has then been transmitted by _heredity_ from generation to generation. -Albrecht Rau has thoroughly established this view in his excellent -work on _Sensation and Thought_, a physiological inquiry into the -nature of the human understanding (1896). It points out the correct -significance of Müller's law of specific sense-energies, adding -searching investigations into their relation to the brain, and in the -last chapter there is an able "philosophy of sensitivity" based on the -ideas of Ludwig Feuerbach. I thoroughly agree with his convincing work. - -Critical comparison of sense-action in man and the other vertebrates -has brought to light a number of extremely important facts, the -knowledge of which we owe to the penetrating research of the -nineteenth century, especially of the second half of the century. This -is particularly true of the two most elaborate "æsthetic" organs, -the eye and the ear. They present a different and more complicated -structure in the vertebrates than in the other animals, and have also -a characteristic development in the embryo. This typical ontogenesis -and structure of the sensilla of all the vertebrates is only explained -by _heredity_ from a common ancestor. Within the vertebrate group, -however, we find a great variety of structure in points of detail, and -this is due to _adaptation_ to their manner of life on the part of the -various species, to the increasing or diminishing use of various parts. - -In respect of the structure of his sense-organs man is by no means -the most perfect and most highly-developed vertebrate. The eye of the -eagle is much keener, and can distinguish small objects at a distance -much more clearly than the human eye. The hearing of many mammals, -especially of the carnivora, ungulata, and rodentia of the desert, is -much more sensitive than that of man, and perceives slight noises at a -much greater distance; that may be seen at a glance by their large and -very sensitive cochlea. Singing birds have attained a higher grade of -development, even in respect of musical endowment, than the majority of -men. The sense of smell is much more developed in most of the mammals, -especially in the carnivora and the ungulata, than in man; if the dog -could compare his own fine scent with that of man, he would look down -on us with compassion. Even with regard to the lower senses--taste, -sex-sense, touch, and temperature--man has by no means reached the -highest stage in every respect. - -We can naturally only pass judgment on the sensations which we -ourselves experience. However, anatomy informs us of the presence in -the bodies of many animals of other senses than those we are familiar -with. Thus fishes and other lower aquatic vertebrates have peculiar -sensilla in the skin which are in connection with special sense-nerves. -On the right and left sides of the fish's body there is a long canal, -branching into a number of smaller canals at the head. In this "mucous -canal" there are nerves with numerous branches, the terminations of -which are connected with peculiar nerve-aggregates. This extensive -epidermic sense-organ probably serves for the perception of changes in -the pressure, or in other properties, of the water. Some groups are -distinguished by the possession of other peculiar sensilla, the meaning -of which is still unknown to us. - -But it is already clear from the above facts that our human -sense-activity is limited, not only in quantity, but in quality also. -We can thus only perceive with our senses, especially with the eye -and the sense of touch, a part of the qualities of the objects in our -environment. And even this partial perception is incomplete, in the -sense that our organs are imperfect, and our sensory nerves, acting -as interpreters, communicate to the brain only a translation of the -impressions received. - -However, this acknowledged imperfection of our senses should not -prevent us from recognizing their instruments, and especially the eye, -to be organs of the highest type; together with the thought-organs in -the brain, they are nature's most valuable gift to man. Very truly does -Albrecht Rau say: "All science is sensitive knowledge in the ultimate -analysis; it does not deny, but interpret, the data of the senses. -The senses are our first and best friends. Long before the mind is -developed the senses tell man what he must do and avoid. He who makes -a general disavowal of the senses in order to meet their dangers acts -as thoughtlessly and as foolishly as the man who plucks out his eyes -because they once fell on shameful things, or the man who cuts off -his hand lest at any time it should reach out to the goods of his -neighbor." Hence Feuerbach is quite right in calling all philosophies, -religions, and systems which oppose the principle of sense-action not -only erroneous, but really pernicious. Without the senses there is -no knowledge--"_Nihil est in intellectu, quod non fuerit in sensu_," -as Locke said. Twenty years ago I pointed out, in my chapter "On the -Origin and Development of the Sense-Organs,"[32] the great service of -Darwinism in giving us a profounder knowledge and a juster appreciation -of the senses. - -The thirst for knowledge of the educated mind is not contented with -the defective acquaintance with the outer world which is obtained -through our imperfect sense-organs. He endeavors to build up the -sense-impressions which they have brought him into valuable knowledge. -He transforms them into specific sense-perceptions in the sense-centres -of the cortex of the brain, and combines them into presentations, -by association, in the thought-centres. Finally, by a further -concatenation of the groups of presentations he attains to connected -knowledge. But this knowledge remains defective and unsatisfactory -until the imagination supplements the inadequate power of combination -of the intelligence, and, by the association of stored-up images, -unites the isolated elements into a connected whole. Thus are produced -new general presentative images, and these suffice to interpret the -facts perceived and satisfy "reason's feeling of causality." - -The presentations which fill up the gaps in our knowledge, or take its -place, may be called, in a broad sense, "faith." That is what happens -continually in daily life. When we are not sure about a thing we say, I -believe it. In this sense we are compelled to make use of faith even in -science itself; we conjecture or assume that a certain relation exists -between two phenomena, though we do not know it for certain. If it is -a question of a _cause_, we form a _hypothesis_; though in science -only such hypotheses are admitted as lie within the sphere of human -cognizance, and do not contradict known facts. Such hypotheses are, for -instance--in physics the theory of the vibratory movement of ether, in -chemistry the hypothesis of atoms and their affinity, in biology the -theory of the molecular structure of living protoplasm, and so forth. - -The explanation of a great number of connected phenomena by the -assumption of a common cause is called a _theory_. Both in theory and -hypothesis "faith" (in the scientific sense) is indispensable; for -here again it is the imagination that fills up the gaps left by the -intelligence in our knowledge of the connection of things. A theory, -therefore, must always be regarded only as an approximation to the -truth; it must be understood that it may be replaced in time by another -and better-grounded theory. But, in spite of this admitted uncertainty, -theory is indispensable for all true science; it elucidates facts by -postulating a cause for them. The man who renounces theory altogether, -and seeks to construct a pure science with certain facts alone -(as often happens with wrong-headed representatives of our "exact -sciences"), must give up the hope of any knowledge of causes, and, -consequently, of the satisfaction of reason's demand for causality. - -The theory of gravitation in astronomy (Newton), the nebular theory -in cosmogony (Kant and Laplace), the principle of energy in physics -(Meyer and Helmholtz), the atomic theory in chemistry (Dalton), the -vibratory theory in optics (Huyghens), the cellular theory in histology -(Schleiden and Schwann), and the theory of descent in biology (Lamarck -and Darwin), are all important theories of the first rank; they explain -a whole world of natural phenomena by the assumption of a common cause -for all the several facts of their respective provinces, and by showing -that all the phenomena thereof are inter-connected and controlled by -laws which issue from this common cause. Yet the cause itself may -remain obscure in character, or be merely a "provisional hypothesis." -The "force of gravity" in the theory of gravitation and in cosmogony, -"energy" itself in its relation to matter, the "ether" of optics -and electricity, the "atom" of the chemist, the living "protoplasm" -of histology, the "heredity" of the evolutionist--these and similar -conceptions of other great theories may be regarded by a sceptical -philosophy as "mere hypotheses" and the outcome of scientific "faith," -yet they are indispensable for us, until they are replaced by better -hypotheses. - -The dogmas which are used for the explanation of phenomena in the -various religions, and which go by the name of "faith" (in the narrower -sense), are of a very different character from the forms of scientific -faith we have enumerated. The two types, however--the "natural" -faith of science and the "supernatural" faith of religion--are not -infrequently confounded, so that we must point out their fundamental -difference. Religious faith means always belief in a miracle, and as -such is in hopeless contradiction with the natural faith of reason. -In opposition to reason it postulates supernatural agencies, and, -therefore, may be justly called superstition. The essential difference -of this superstition from rational faith lies in the fact that it -assumes supernatural forces and phenomena, which are unknown and -inadmissible to science, and which are the outcome of illusion and -fancy; moreover, superstition contradicts the well-known laws of -nature, and is therefore _irrational_. - -Owing to the great progress of ethnology during the century, we -have learned a vast quantity of different kinds and practices of -superstition, as they still survive in uncivilized races. When they are -compared with each other and with the mythological notion of earlier -ages, a manifold analogy is discovered, frequently a common origin, and -eventually one simple source for them all. This is found in the "demand -of causality in reason," in the search for an explanation of obscure -phenomena by the discovery of a cause. That applies particularly to -such phenomena as threaten us with danger and excite fear, like thunder -and lightning, earthquakes, eclipses, etc. The demand for a causal -explanation of such phenomena is found in uncivilized races of the -lowest grade, transmitted from their primate ancestors by heredity. It -is even found in many other vertebrates. When a dog barks at the full -moon, or at a ringing bell, of which it sees the hammer moving, or at a -flag that flutters in the breeze, it expresses not only fear, but also -the mysterious impulse to learn the cause of the obscure phenomenon. -The crude beginnings of religion among primitive races spring partly -from this hereditary superstition of their primate ancestors, and -partly from the worship of ancestors, from various emotional impulses, -and from habits which have become traditional. - -The religious notions of modern civilized peoples, which they esteem -so highly, profess to be on a much higher level than the "crude -superstition" of the savage; we are told of the great advance which -civilization has made in sweeping it aside. That is a great mistake. -Impartial comparison and analysis show that they only differ in -their special "form of faith" and the outer shell of their creed. -In the clear light of reason the refined faith of the most liberal -ecclesiastical religion--inasmuch as it contradicts the known and -inviolable laws of nature--is no less irrational a superstition than -the crude spirit-faith of primitive fetichism on which it looks down -with proud disdain. - -And if, from this impartial stand-point, we take a critical glance at -the kinds of faith that prevail to-day in civilized countries, we find -them everywhere saturated with traditional superstition. The Christian -belief in Creation, the Trinity, the Immaculate Conception, the -Redemption, the Resurrection and Ascension of Christ, and so forth, is -just as purely imaginative as the belief in the various dogmas of the -Mohammedan, Mosaic, Buddhistic, and Brahmanic religions, and is just -as incapable of reconciliation with a rational knowledge of nature. -Each of these religions is for the sincere believer an indisputable -truth, and each regards the other as heresy and damnable error. The -more confidently a particular sect considers itself "the only ark -of salvation," and the more ardently this conviction is cherished, -the more zealously does it contend against all other sects and give -rise to the fearful religious wars that form the saddest pages in the -book of history. And all the time the unprejudiced "critique of pure -reason" teaches us that all these different forms of faith are equally -false and irrational, mere creatures of poetic fancy and uncritical -tradition. Rational science must reject them all alike as the outcome -of superstition. - -The incalculable injury which irrational superstition has done -to credulous humanity is conspicuously revealed in the ceaseless -conflict of confessions of faith. Of all the wars which nations have -waged against each other with fire and sword the religious wars have -been the bloodiest; of all the forms of discord that have shattered -the happiness of families and of individuals those that arise from -religious differences are still the most painful. Think of the millions -who have lost their lives in Christian persecutions, in the religious -conflicts of Islam and of the Reformation, by the Inquisition, and -under the charge of witchcraft. Or think of the still greater number -of luckless men who, through religious differences, have been plunged -into family troubles, have lost the esteem of their fellow-citizens -and their position in the community, or have even been compelled to -fly from their country. The official confession of faith becomes most -pernicious of all when it is associated with the political aims of -a modern state, and is enforced as "religious instruction" in our -schools. The child's mind is thus early diverted from the pursuit of -the truth and impregnated with superstition. Every friend of humanity -should do all in his power to promote unsectarian schools as one of the -most valuable institutions of the modern state. - -The great value which is, none the less, still very widely attached -to sectarian instruction is not only due to the compulsion of a -reactionary state and its dependence on a dominant clericalism, but -also to the weight of old traditions and "emotional cravings" of -various kinds. One of the strongest of these is the devout reverence -which is extended everywhere to sectarian tradition, to the "faith -of our fathers." In thousands of stories and poems fidelity to it -is extolled as a spiritual treasure and a sacred duty. Yet a little -impartial study of the history of faith suffices to show the absurdity -of the notion. The dominant evangelical faith of the second half of -the nineteenth century is essentially different from that of the first -half, and this again from that of the eighteenth century. The faith of -the eighteenth century diverges considerably from the "faith of our -fathers" of the seventeenth, and still more from that of the sixteenth, -century. The Reformation, releasing enslaved reason from the tyranny of -the popes, is naturally regarded by them as darkest heresy; but even -the faith of the papacy itself had been completely transformed in the -course of a century. And how different is the faith of the Christian -from that of his heathen ancestors. Every man with some degree of -independent thought frames a more or less personal religion for -himself, which is always different from that of his fathers; it depends -largely on the general condition of thought in his day. The further we -go back in the history of civilization, the more clearly do we find -this esteemed "faith of our fathers" to be an indefensible superstition -which is undergoing continual transformation. - -One of the most remarkable forms of superstition, which still takes a -very active part in modern life, is _spiritism_. It is a surprising -and a lamentable fact that millions of educated people are still -dominated by this dreary superstition; even distinguished scientists -are entangled in it. A number of spiritualist journals spread the -faith far and wide, and our "superior circles" do not scruple to hold -_séances_ in which "spirits" appear, rapping, writing, giving messages -from "the beyond," and so on. It is a frequent boast of spiritists that -even eminent men of science defend their superstition. In Germany, A. -Zöllner and Fechner are quoted as instances; in England, Wallace and -Crookes. The regrettable circumstance that physicists and biologists -of such distinction have been led astray by spiritism is accounted -for, partly by their excess of imagination and defect of critical -faculty, and partly by the powerful influence of dogmas which a -religious education imprinted on the brain in early youth. Moreover, -it was precisely through the famous _séances_ at Leipzig, in which the -physicists, Zöllner, Fechner, and Wilhelm Weber, were imposed on by -the clever American conjuror, Slade, that the fraud of the latter was -afterwards fully exposed; he was discovered to be a common impostor. -In other cases, too, where the alleged marvels of spiritism have been -thoroughly investigated, they have been traced to a more or less clever -deception; the mediums (generally of the weaker sex) have been found to -be either smart swindlers or nervous persons of abnormal irritability. -Their supposed gift of "telepathy" (or "action at a distance of thought -without material medium") has no more existence than the "voices" or -the "groans" of spirits, etc. The vivid pictures which Carl du Prel, of -Munich, and other spiritists give of their phenomena must be regarded -as the outcome of a lively imagination, together with a lack of -critical power and of knowledge of physiology. - -The majority of religions have, in spite of their great differences, -one common feature, which is, at the same time, one of their strongest -supports in many quarters. They declare that they can elucidate the -problem of existence, the solution of which is beyond the natural power -of reason, by the supernatural way of revelation; from that they derive -the authority of the dogmas which in the guise of "divine laws" control -morality and the practical conduct of life. "Divine" inspirations of -that kind form the basis of many myths and legends, the human origin of -which is perfectly clear. It is true that the God who reveals himself -does not always appear in human shape, but in thunder and lightning, -storm and earthquake, fiery bush or menacing cloud. But the revelation -which he is supposed to bring to the credulous children of men is -always anthropomorphic; it invariably takes the form of a communication -of ideas or commands which are formulated and expressed precisely as is -done in the normal action of the human brain and larynx. In the Indian -and Egyptian religions, in the mythologies of Greece and Rome, in the -Old and the New Testaments, the gods think, talk, and act just as men -do; the revelations, in which they are supposed to unveil for us the -secrets of existence and the solution of the great world-enigma, are -creations of the human imagination. The "truth" which the credulous -discover in them is a human invention; the "childlike faith" in these -irrational revelations is mere superstition. - -The true revelation--that is, the true source of rational knowledge--is -to be sought in nature alone. The rich heritage of truth which forms -the most valuable part of human culture is derived exclusively from -the experiences acquired in a searching study of nature, and from the -rational conclusions which it has reached by the just association of -these empirical presentations. Every intelligent man with normal brain -and senses finds this true revelation in nature on impartial study, and -thus frees himself from the superstition with which the "revelations" -of religion had burdened him. - - - - -CHAPTER XVII - -SCIENCE AND CHRISTIANITY - - Increasing Opposition between Modern Science and Christian - Theology--The Old and the New Faith--Defence of Rational Science - against the Attacks of Christian Superstition, especially against - Catholicism--Four Periods in the Evolution of Christianity: - I. Primitive Christianity (the First Three Centuries)--The - Four Canonical Gospels--The Epistles of Paul--II. The Papacy - (Ultramontane Christianity)--Retrogression of Civilization in the - Middle Ages--Ultramontane Falsification of History--The Papacy and - Science--The Papacy and Christianity--III. The Reformation--Luther - and Calvin--The Year of Emancipation--IV. The Pseudo-Christianity - of the Nineteenth Century--The Papal Declaration of War against - Reason and Science: (_a_) Infallibility, (_b_) The Encyclica, (_c_) - The Immaculate Conception - - -One of the most distinctive features of the expiring century is -the increasing vehemence of the opposition between science and -Christianity. That is both natural and inevitable. In the same -proportion in which the victorious progress of modern science has -surpassed all the scientific achievements of earlier ages has the -untenability been proved of those mystic views which would subdue -reason under the yoke of an alleged revelation; and the Christian -religion belongs to that group. The more solidly modern astronomy, -physics, and chemistry have established the sole dominion of inflexible -natural laws in the universe at large, and modern botany, zoology, -and anthropology have proved the validity of those laws in the entire -kingdom of organic nature, so much the more strenuously has the -Christian religion, in association with dualistic metaphysics, striven -to deny the application of these natural laws in the province of the -so-called "spiritual life"--that is, in one section of the physiology -of the brain. - -No one has more clearly, boldly, and unanswerably enunciated this -open and irreconcilable opposition between the modern scientific and -the outworn Christian view than David Friedrich Strauss, the greatest -theologian of the nineteenth century. His last work, _The Old Faith -and the New_, is a magnificent expression of the honest conviction of -all educated people of the present day who understand this unavoidable -conflict between the discredited, dominant doctrines of Christianity -and the illuminating, rational revelation of modern science--all -those who have the courage to defend the right of reason against the -pretensions of superstition, and who are sensible of the philosophic -demand for a unified system of thought. Strauss, as an honorable and -courageous free-thinker, has expounded far better than I could the -principal points of difference between "the old and the new faith." -The absolute irreconcilability of the opponents and the inevitability -of their struggle ("for life or death") have been ably presented on -the philosophic side by E. Hartmann, in his interesting work on _The -Self-Destruction of Christianity_. - -When the works of Strauss and Feuerbach and _The History of the -Conflict between Religion and Science_ of J. W. Draper have been read, -it may seem superfluous for us to devote a special chapter to the -subject. Yet we think it useful, and even necessary for our purpose, -to cast a critical glance at the historical course of this great -struggle; especially seeing that the attacks of the "Church militant" -on science in general, and on the theory of evolution in particular, -have become extremely bitter and menacing of late years. Unfortunately, -the mental relaxation which has lately set in, and the rising flood of -reaction in the political, social, and ecclesiastical world, are only -too well calculated to give point to those dangers. If any one doubts -it, he has only to look over the conduct of Christian synods and of the -German Reichstag during the last few years. Quite in harmony are the -recent efforts of many secular governments to get on as good a footing -as possible with the "spiritual regiment," their deadly enemy--that -is, to submit to its yoke. The two forces find a common aim in the -suppression of free thought and free scientific research, for the -purpose of thus more easily securing a complete despotism. - -Let us first emphatically protest that it is a question for us of the -necessary defence of science and reason against the vigorous attacks -of the Christian Church and its vast army, not of an unprovoked -attack of science on religion. And, in the first place, our defence -must be prepared against Romanism or Ultramontanism. This "one ark -of salvation," this Catholic Church "destined for all," is not only -much larger and more powerful than the other Christian sects, but it -has the exceptional advantage of a vast, centralized organization -and an unrivalled political ability. Men of science are often heard -to say that the Catholic superstition is no more astute than the -other forms of supernatural faith, and that all these insidious -institutions are equally inimical to reason and science. As a matter -of general theoretical principle the statement may pass, but it is -certainly wrong when we look to its practical side. The deliberate and -indiscriminate attacks of the ultramontane Church on science, supported -by the apathy and ignorance of the masses, are, on account of its -powerful organization, much more severe and dangerous than those of -other religions. - -In order to appreciate correctly the extreme importance of Christianity -in regard to the entire history of civilization, and particularly -its fundamental opposition to reason and science, we must briefly -run over the principal stages of its historical evolution. It may be -divided into four periods: (1) primitive Christianity (the first three -centuries), (2) papal Christianity (twelve centuries, from the fourth -to the fifteenth), (3) the Reformation (three centuries, from the -sixteenth to the eighteenth), and (4) modern pseudo-Christianity. - - -I.--PRIMITIVE CHRISTIANITY - -Primitive Christianity embraces the first three centuries. Christ -himself, the noble prophet and enthusiast, so full of the love of -humanity, was far below the level of classical culture; he knew nothing -beyond the Jewish traditions; he has not left a single line of writing. -He had, indeed, no suspicion of the advanced stage to which Greek -philosophy and science had progressed five hundred years before. - -All that we know of him and of his original teaching is taken from the -chief documents of the New Testament--the four gospels and the Pauline -epistles. As to the four canonical gospels, we now know that they were -selected from a host of contradictory and forged manuscripts of the -first three centuries by the three hundred and eighteen bishops who -assembled at the Council of Nicæa in 327. The entire list of gospels -numbered forty; the canonical list contains four. As the contending -and mutually abusive bishops could not agree about the choice, they -determined to leave the selection to a miracle. They put all the books -(according to the _Synodicon_ of Pappus) together underneath the -altar, and prayed that the apocryphal books, of human origin, might -remain there, and the genuine, inspired books might be miraculously -placed on the table of the Lord. And that, says tradition, really -occurred! The three synoptic gospels (Matthew, Mark, and Luke--all -written _after_ them, not _by_ them, at the beginning of the second -century) and the very different fourth gospel (ostensibly "after" -John, written about the middle of the second century) leaped on the -table, and were thenceforth recognized as the inspired (with their -thousand mutual contradictions) foundations of Christian doctrine. If -any modern "unbeliever" finds this story of the "leap of the sacred -books" incredible, we must remind him that it is just as credible as -the table-turning and spirit-rapping that are believed to take place -to-day by millions of educated people; and that hundreds of millions of -Christians believe just as implicitly in their personal immortality, -their "resurrection from the dead," and the Trinity of God--dogmas that -contradict pure reason no more and no less than that miraculous bound -of the gospel manuscripts. - -The most important sources after the gospels are the fourteen separate -(and generally forged) epistles of Paul. The genuine Pauline epistles -(_three_ in number, according to recent criticism--to the Romans, -Galatians, and Corinthians) were written before the canonical gospels, -and contain less incredible miraculous matter than they. They are -also more concerned than the gospels to adjust themselves with a -rational view of the world. Hence the advanced theology of modern times -constructs its "ideal Christianity" rather on the base of the Pauline -epistles than on the gospels, so that it has been called "Paulinism." - -The remarkable personality of Paul, who possessed much more culture -and practical sense than Christ, is extremely interesting, from the -anthropological point of view, from the fact that the racial origin -of the two great religious founders is very much the same. Recent -historical investigation teaches that Paul's father was of Greek -nationality, and his mother of Jewish.[33] The half-breeds of these two -races, which are so very distant in origin (although they are branches -of the same species, the _homo mediterraneus_), are often distinguished -by a happy blending of talents and temperament, as we find in many -recent and actual instances. The plastic Oriental imagination and the -critical Western reason often admirably combine and complete each -other. That is visible in the Pauline teaching, which soon obtained a -greater influence than the earliest Christian notions. Hence it is not -incorrect to consider Paulinism a new phenomenon, of which the father -was the philosophy of the Greeks, and the mother the religion of the -Jews. Neoplatonism is an analogous combination. - -As to the real teaching and aims of Christ (and as to many important -aspects of his life) the views of conflicting theologians diverge -more and more, as historical criticism (Strauss, Feuerbach, Baur, -Renan, etc.) puts the accessible facts in their true light, and draws -impartial conclusions from them. Two things, certainly, remain beyond -dispute--the lofty principle of universal charity and the fundamental -maxim of ethics, the "golden rule," that issues therefrom; both, -however, existed in theory and in practice centuries before the time -of Christ (cf. chap. xix.). For the rest, the Christians of the early -centuries were generally pure Communists, sometimes "Social Democrats," -who, according to the prevailing theory in Germany to-day, ought to -have been exterminated with fire and sword. - - -II.--PAPAL CHRISTIANITY - -Latin Christianity, variously called Papistry, Romanism, Vaticanism, -Ultramontanism, or the Roman Catholic Church, is one of the most -remarkable phenomena in the history of civilized man; in spite of -the storms that have swept over it, it still exerts a most powerful -influence. Of the four hundred and ten million Christians who are -scattered over the earth the majority--that is, two hundred and -twenty-five millions--are Roman Catholics; there are seventy-five -million Greek Catholics and one hundred and ten million Protestants. -During a period of one thousand two hundred years, from the fourth to -the sixteenth century, the papacy has almost absolutely controlled and -tainted the spiritual life of Europe; on the other hand, it has won but -little territory from the ancient religions of Asia and Africa. In Asia -Buddhism still counts five hundred and three million followers, the -Brahmanic religion one hundred and thirty-eight millions, and Islam one -hundred and twenty millions. - -It is the despotism of the papacy that lent its darkest character to -the Middle Ages; it meant death to all freedom of mental life, decay -to all science, corruption to all morality. From the noble height to -which the life of the human mind had attained in classical antiquity, -in the centuries before Christ and the first century after Christ, -it soon sank, under the rule of the papacy, to a level which, in -respect of the knowledge of the truth, can only be termed barbarism. -It is often protested that other aspects of mental life--poetry and -architecture, scholastic learning and patristic philosophy--were richly -developed in the Middle Ages. But this activity was in the service of -the Church; it did not tend to the cultivation, but to the suppression, -of free mental research. The exclusive preparing for an unknown -eternity beyond the tomb, the contempt of nature, the withdrawal from -the study of it, which are essential elements of Christianity, were -urged as a sacred duty by the Roman hierarchy. It was not until the -beginning of the sixteenth century that a change for the better came in -with the Reformation. - -It is impossible for us here to describe the pitiful retrogression -of culture and morality during the twelve centuries of the spiritual -despotism of Rome. It is very pithily expressed in a saying of the -greatest and the ablest of the Hohenzollerns; Frederick the Great -condensed his judgment in the phrase that the study of history led -one to think that from Constantine to the date of the Reformation the -whole world was insane. L. Büchner has given us an admirable, brief -description of this "period of insanity" in his work on _Religious -and Scientific Systems_. The reader who desires a closer acquaintance -with the subject would do well to consult the historical works of -Ranke, Draper, Kolb, Svoboda, etc. The truthful description of the -awful condition of the Christian Middle Ages, which is given by these -and other unprejudiced historians, is confirmed by all the reliable -sources of investigation, and by the historical monuments which -have come down from the saddest period of human history. Educated -Catholics, who are sincere truth-seekers, cannot be too frequently -recommended to study these historical sources for themselves. This is -the more necessary as ultramontane literature has still a considerable -influence. The old trick of deceiving the faithful by a complete -reversal of facts and an invention of miraculous circumstances is -still worked by it with great success. We will only mention Lourdes -and the "Holy Coat" of Trêves. The ultramontane professor of history -at Frankfurt, Johannes Janssen, affords a striking example of the -length they will go in distorting historical truth; his much-read works -(especially his _History of the German People since the Middle Ages_) -are marred by falsification to an incredible extent. The untruthfulness -of these Jesuitical productions is on a level with the credulity and -the uncritical judgment of the simple German nation that takes them for -gospel. - -One of the most interesting of the historical facts which clearly prove -the evil of the ultramontane despotism is its vigorous and consistent -struggle with science. This was determined on, in principle, from the -very beginning of Christianity, inasmuch as it set faith above reason -and preached the blind subjection of the one to the other; that was -natural, seeing that our whole life on earth was held to be only a -preparation for the legendary life beyond, and thus scientific research -was robbed of any real value. The deliberate and successful attack on -science began in the early part of the fourth century, particularly -after the Council of Nicæa (327), presided over by Constantine--called -the "Great" because he raised Christianity to the position of a state -religion, and founded Constantinople, though a worthless character, -a false-hearted hypocrite, and a murderer. The success of the papacy -in its conflict with independent scientific thought and inquiry is -best seen in the distressing condition of science and its literature -during the Middle Ages. Not only were the rich literary treasures -that classical antiquity had bequeathed to the world destroyed for -the most part, or withdrawn from circulation, but the rack and the -stake insured the silence of every heretic--that is, every independent -thinker. If he did not keep his thoughts to himself, he had to look -forward to being burned alive, as was the fate of the great monistic -philosopher, Giordano Bruno, the reformer, John Huss, and more than a -hundred thousand other "witnesses to the truth." The history of science -in the Middle Ages teaches us on every page that independent thought -and empirical research were completely buried for twelve sad centuries -under the oppression of the omnipotent papacy. - -All that we esteem in true Christianity, in the sense of its founder -and of his noblest followers, and that we must endeavor to save from -the inevitable wreck of this great world religion for our new monistic -religion, lies on its ethical and social planes. The principles of -true humanism, the golden rule, the spirit of tolerance, the love -of man, in the best and highest sense of the word--all these true -graces of Christianity were not, indeed, first discovered and given -to the world by that religion, but were successfully developed in the -critical period when classical antiquity was hastening to its doom. -The papacy, however, has attempted to convert all those virtues into -the direct contrary, and still to hang out the sign of the old firm. -Instead of Christian charity, it introduced a fanatical hatred of the -followers of all other religions; with fire and sword it has pursued, -not only the heathen, but every Christian sect that dared resist the -imposition of ultramontane dogma. Tribunals for heretics were erected -all over Europe, yielding unnumbered victims, whose torments seemed -only to fill their persecutors, with all their Christian charity, with -a peculiar satisfaction. The power of Rome was directed mercilessly -for centuries against everything that stood in its way. Under the -notorious Torquemada (1481-98), in Spain alone eight thousand heretics -were burned alive and ninety thousand punished with the confiscation -of their goods and the most grievous ecclesiastical fines; in the -Netherlands, under the rule of Charles V., at least fifty thousand -men fell victims to the clerical bloodthirst. And while the heavens -resounded with the cry of the martyrs, the wealth of half the world was -pouring into Rome, to which the whole of Christianity paid tribute, and -the self-styled representatives of God on earth and their accomplices -(not infrequently Atheists themselves) wallowed in pleasure and vice -of every description. "And all these privileges," said the frivolous, -syphilitic Pope, Leo X., "have been secured to us by the fable of Jesus -Christ." - -Yet, with all the discipline of the Church and the fear of God, the -condition of European society was pitiable. Feudalism, serfdom, the -grace of God, and the favor of the monks ruled the land; the poor -helots were only too glad to be permitted to raise their miserable -huts under the shadow of the castle or the cloister, their secular and -spiritual oppressors and exploiters. Even to-day we suffer from the -aftermath of these awful ages and conditions, in which there was no -question of care for science or higher mental culture save in rare -circumstances and in secret. Ignorance, poverty, and superstition -combined with the immoral operation of the law of celibacy, which -had been introduced in the eleventh century, to consolidate the -ever-growing power of the papacy. It has been calculated that there -were more than ten million victims of fanatical religious hatred during -this "Golden Age" of papal domination; and how many more million human -victims must be put to the account of celibacy, oral confession, and -moral constraint, the most pernicious and accursed institutions of -the papal despotism! Unbelieving philosophers, who have collected -disproofs of the existence of God, have overlooked one of the strongest -arguments in that sense--the fact that the Roman "Vicar of Christ" -could for twelve centuries perpetrate with impunity the most shameful -and horrible deeds "in the name of God." - - -III.--THE REFORMATION - -The history of civilization, which we are so fond of calling "the -history of the world," enters upon its third period with the -Reformation of the Christian Church, just as its second period begins -with the founding of Christianity. With the Reformation begins the -new birth of fettered reason, the reawakening of science, which the -iron hand of the Christian papacy had relentlessly crushed for twelve -hundred years. At the same time the spread of general education had -already commenced, owing to the invention of printing about the -middle of the fifteenth century; and towards its close several great -events occurred, especially the discovery of America in 1492, which -prepared the way for the "renaissance" of science in company with -that of art. Indeed, certain very important advances were made in the -knowledge of nature during the first half of the sixteenth century, -which shook the prevailing system to its very foundations. Such were -the circumnavigation of the globe by Magellan in 1522, which afforded -empirical proof of its rotundity, and the founding of the new system of -the world by Copernicus in 1543. - -Yet the 31st of October in the year 1517, the day on which Martin -Luther nailed his ninety-five theses to the wooden door of Wittenburg -Cathedral, must be regarded as the commencement of a new epoch; for -on that day was forced the iron door of the prison in which the Papal -Church had detained fettered reason for twelve hundred years. The -merits of the great reformer have been partly exaggerated, partly -underestimated. It has been justly pointed out that Luther, like all -the other reformers, remained in manifold subjection to the deepest -superstition. Thus he was throughout life a supporter of the rigid -dogma of the verbal inspiration of the Bible; he zealously maintained -the doctrines of the resurrection, original sin, predestination, -justification by faith, etc. He rejected as folly the great discovery -of Copernicus, because in the Bible "Joshua bade the sun, not the -earth, stand still." He utterly failed to appreciate the great -political revolutions of his time, especially the profound and just -agitation of the peasantry. Worse still was the fanatical Calvin, of -Geneva, who had the talented Spanish physician, Serveto, burned alive -in 1553, because he rejected the absurd dogma of the Trinity. The -fanatical "true believers" of the reformed Church followed only too -frequently in the blood-stained footsteps of their papal enemies; as -they do even in our own day. Deeds of unparalleled cruelty followed -in the train of the Reformation--the massacre of St. Bartholomew and -the persecution of the Huguenots in France, bloody heretic-hunts in -Italy, civil war in England, and the Thirty Years War in Germany. Yet, -in spite of those grave blemishes, to the sixteenth and seventeenth -centuries belongs the honor of once more opening a free path to the -thoughtful mind, and delivering reason from the oppressive yoke of the -papacy. Thus only was made possible that great development of different -tendencies in critical philosophy and of new paths in science which -won for the subsequent eighteenth century the honorable title of "the -century of enlightenment." - - -IV.--THE PSEUDO-CHRISTIANITY OF THE NINETEENTH CENTURY - -As the fourth and last stage in the history of Christianity we oppose -our nineteenth century to all its predecessors. It is true that the -enlightenment of preceding centuries had promoted critical thought in -every direction, and the rise of science itself had furnished powerful -empirical weapons; yet it seems to us that our progress along both -lines has been quite phenomenal during the nineteenth century. It -has inaugurated an entirely new period in the history of the human -mind, characterized by the development of the monistic philosophy -of nature. At its very commencement the foundations were laid of a -new anthropology (by the comparative anatomy of Cuvier) and of a new -biology (by the _Philosophie Zoologique_ of Lamarck). The two great -French scientists were quickly succeeded by two contemporary German -scholars--Baer, the founder of the science of evolution, and Johannes -Müller, the founder of comparative morphology and physiology. A -pupil of Müller, Theodor Schwann, created the far-reaching cellular -theory in 1838, in conjunction with M. Schleiden. Lyell had already -traced the evolution of the earth to natural causes, and thus proved -the application to our planet of the mechanical cosmogony which Kant -had sketched with so much insight in 1755. Finally, Robert Mayer and -Helmholtz established the principle of energy in 1842--the second, -complementary half of the great law of substance, the first half of -which (the persistence of matter) had been previously discovered by -Lavoisier. Forty years ago Charles Darwin crowned all these profound -revelations of the intimate nature of the universe by his new theory -of evolution, the greatest natural-philosophical achievement of our -century. - -What is the relation of modern Christianity to this vast and -unparalleled progress of science? In the first place, the deep gulf -between its two great branches, conservative Romanism and progressive -Protestantism, has naturally widened. The ultramontane clergy (and -we must associate with them the orthodox "evangelical alliance") had -naturally to offer a strenuous opposition to this rapid advance of -the emancipated mind; they continued unmoved in their rigid literal -belief, demanding the unconditional surrender of reason to dogma. -Liberal Protestantism, on the other hand, took refuge in a kind of -monistic pantheism, and sought a means of reconciling two contradictory -principles. It endeavored to combine the unavoidable recognition of -the established laws of nature, and the philosophic conclusions that -followed from them, with a purified form of religion, in which scarcely -anything remained of the distinctive teaching of faith. There were -many attempts at compromise to be found between the two extremes; but -the conviction rapidly spread that dogmatic Christianity had lost every -foundation, and that only its valuable ethical contents should be saved -for the new monistic religion of the twentieth century. As, however, -the existing external forms of the dominant Christian religion remained -unaltered, and as, in spite of a progressive political development, -they are more intimately than ever connected with the practical needs -of the State, there has arisen that widespread religious profession -in educated spheres which we can only call "pseudo-Christianity"--at -the bottom it is a "religious lie" of the worst character. The great -dangers which attend this conflict between sincere conviction and the -hypocritical profession of modern pseudo-Christians are admirably -described in Max Nordau's interesting work on _The Conventional Lies of -Civilization_. - -In the midst of this obvious falseness of prevalent pseudo-Christianity -there is one favorable circumstance for the progress of a rational -study of nature: its most powerful and bitterest enemy, the Roman -Church, threw off its mask of ostensible concern for higher mental -development about the middle of the nineteenth century, and declared -a _guerre à l'outrance_ against independent science. This happened -in three important challenges to reason, for the explicitness and -resoluteness of which modern science and culture cannot but be -grateful to the "Vicar of Christ." (1) In December, 1854, the pope -promulgated the dogma of the immaculate conception of Mary. (2) Ten -years afterwards--in December, 1864--the pope published, in his -famous _encyclica_, an absolute condemnation of the whole of modern -civilization and culture; in the _syllabus_ that accompanied it he -enumerated and anathematized all the rational theses and philosophical -principles which are regarded by modern science as lucid truths. (3) -Finally, six years afterwards--on July 13, 1870--the militant head of -the Church crowned his folly by claiming _infallibility_ for himself -and all his predecessors in the papal chair. This triumph of the Roman -_curia_ was communicated to the astonished world five days afterwards, -on the very day on which France declared war with Prussia. Two months -later the temporal power of the pope was taken from him in consequence -of the war. - -These three stupendous acts of the papacy were such obvious assaults on -the reason of the nineteenth century that they gave rise, from the very -beginning, to a most heated discussion even within orthodox Catholic -circles. When the Vatican Council proceeded to define the dogma of -infallibility on July 13, 1870, only three-fourths of the bishops -declared in its favor, 451 out of 601 assenting; many other bishops, -who wished to keep clear of the perilous definition, were absent from -the council. But the shrewd pontiff had calculated better than the -timid "discreet Catholics": even this extraordinary dogma was blindly -accepted by the credulous and uneducated masses of the faithful. - -The whole history of the papacy, as it is substantiated by a thousand -reliable sources and accessible documents, appears to the impartial -student as an unscrupulous tissue of lying and deceit, a reckless -pursuit of absolute mental despotism and secular power, a frivolous -contradiction of all the high moral precepts which true Christianity -enunciates--charity and toleration, truth and chastity, poverty and -self-denial. When we judge the long series of popes and of the Roman -princes of the Church, from whom the pope is chosen, by the standard of -pure Christian morality, it is clear that the great majority of them -were pitiful impostors, many of them utterly worthless and vicious. -These well-known historical facts, however, do not prevent millions -of educated Catholics from admitting the infallibility which the pope -has claimed for himself; they do not prevent Protestant princes from -going to Rome, and doing reverence to the pontiff (their most dangerous -enemy); they do not prevent the fate of the German people from being -intrusted to-day to the hands of the servants and followers of this -"pious impostor" in the Reichstag--thanks to the incredible political -indolence and credulity of the nation. - -The most interesting of the three great events by which the papacy has -endeavored to maintain and strengthen its despotism in the nineteenth -century is the publication of the encyclica and the syllabus in -December, 1864. In these remarkable documents all independent action -was forbidden to reason and science, and they were commanded to submit -implicitly to faith--that is, to the decrees of the infallible pope. -The great excitement which followed this sublime piece of effrontery in -educated and independent circles was in proportion with the stupendous -contents of the encyclica. Draper has given us an excellent discussion -of its educational and political significance in his _History of the -Conflict between Science and Religion_. - -The dogma of the immaculate conception seems, perhaps, to be less -audacious and significant than the encyclica and the dogma of the -infallibility of the pope. Yet not only the Roman hierarchy, but -even some of the orthodox Protestants (the Evangelical Alliance, for -instance), attach great importance to this thesis. What is known -as the "immaculate oath"--that is, the confirmation of faith by an -oath taken on the immaculate conception of Mary--is still regarded by -millions of Christians as a sacred obligation. Many believers take the -dogma in a twofold application; they think that the mother of Mary was -impregnated by the Holy Ghost as well as Mary herself. Comparative and -critical theology has recently shown that this myth has no greater -claim to originality than most of the other stories in the Christian -mythology; it has been borrowed from older religions, especially -Buddhism. Similar myths were widely circulated in India, Persia, -Asia Minor, and Greece several centuries before the birth of Christ. -Whenever a king's unwedded daughter, or some other maid of high degree, -gave birth to a child, the father was always pronounced to be a god, or -a demi-god; in the Christian case it was the Holy Ghost. - -The special endowments of mind or body which often distinguished these -"children of love" above ordinary offspring were thus partly explained -by "heredity." Distinguished "sons of God" of this kind were held in -high esteem both in antiquity and during the Middle Ages, while the -moral code of modern civilization reproaches them with their want of -honorable parentage. This applies even more forcibly to "daughters of -God," though the poor maidens are just as little to blame for their -want of a father. For the rest, every one who is familiar with the -beautiful mythology of classical antiquity knows that these sons and -daughters of the Greek and Roman gods often approach nearest to the -highest ideal of humanity. Recollect the large legitimate family, and -the still more numerous illegitimate offspring, of Zeus. - -To return to the particular question of the impregnation of the Virgin -Mary by the Holy Ghost, we are referred to the gospels for testimony -to the fact. The only two evangelists who speak of it, Matthew and -Luke, relate in harmony that the Jewish maiden Mary was betrothed to -the carpenter Joseph, but became pregnant without his co-operation, -and, indeed, "by the Holy Ghost." As we have already related, the -four canonical gospels which are regarded as the only genuine ones -by the Christian Church, and adopted as the foundation of faith, -were deliberately chosen from a much larger number of gospels, the -details of which contradict each other sometimes just as freely as the -assertions of the four. The fathers of the Church enumerate from forty -to fifty of these spurious or apocryphal gospels; some of them are -written both in Greek and Latin--for instance, the gospel of James, of -Thomas, of Nicodemus, and so forth. The details which these apocryphal -gospels give of the life of Christ, especially with regard to his birth -and childhood, have just as much (or, on the whole, just as little) -claim to historical validity as the four canonical gospels. - -Now we find in one of these documents an historical statement, -confirmed, moreover, in the _Sepher Toldoth Jeschua_, which probably -furnishes the simple and natural solution of the "world-riddle" of the -supernatural conception and birth of Christ. The author curtly gives us -in one sentence the remarkable statement which contains this solution: -"Josephus Pandera, the Roman officer of a Calabrian legion which was in -Judæa, seduced Miriam of Bethlehem, and was the father of Jesus." Other -details given about Miriam (the Hebrew name for Mary) are far from -being to the credit of the "Queen of Heaven." - -Naturally, these historical details are carefully avoided by the -official theologian, but they assort badly with the traditional myth, -and lift the veil from its mystery in a very simple and natural -fashion. That makes it the more incumbent on impartial research and -pure reason to make a critical examination of these statements. It -must be admitted that they have much more title to credence than all -the other statements about the birth of Christ. When, on familiar -principles of science, we put aside the notion of supernatural -conception through an "overshadowing of the Most High" as a pure myth, -there only remains the widely accepted version of modern rational -theology--that Joseph, the Jewish carpenter, was the true father of -Christ. But this assumption is explicitly contradicted by many texts -of the gospels; Christ himself was convinced that he was a "Son of -God," and he never recognized his foster-father, Joseph, as his real -parent. Joseph, indeed, wanted to leave his betrothed when he found her -pregnant without his interference. He gave up this idea when an angel -appeared to him in a dream and pacified him. As it is expressly stated -in the first chapter of Matthew (vv. 24, 25), there was no sexual -intercourse between Joseph and Mary until after Jesus was born. - -The statement of the apocryphal gospels, that the Roman officer, -Pandera, was the true father of Christ, seems all the more credible -when we make a careful anthropological study of the personality -of Christ. He is generally regarded as purely Jewish. Yet the -characteristics which distinguish his high and noble personality, -and which give a distinct impress to his religion, are certainly not -Semitical; they are rather features of the higher Arian race, and -especially of its noblest branch, the Hellenes. Now, the name of -Christ's real father, "Pandera," points unequivocally to a Greek -origin; in one manuscript, in fact, it is written "Pandora." Pandora -was, according to the Greek mythology, the first woman, born of -the earth by Vulcan and adorned with every charm by the gods, who -was espoused by Epimetheus, and sent by Zeus to men with the dread -"Pandora-box," containing every evil, in punishment for the stealing of -divine fire from heaven by Prometheus. - -And it is interesting to see the different reception that the -love-story of Miriam has met with at the hands of the four great -Christian nations of civilized Europe. The stern morality of the -Teutonic races entirely repudiates it; the righteous German and the -prudish Briton prefer to believe blindly in the impossible thesis of a -conception "by the Holy Ghost." It is well known that this strenuous -and carefully paraded prudery of the higher classes (especially in -England) is by no means reflected in the true condition of sexual -morality in high quarters. The revelations which the _Pall Mall -Gazette_, for instance, made on the subject twelve years ago vividly -recalled the condition of Babylon. - -The Romantic races, which ridicule this prudery and take sexual -relations less seriously, find _Mary's Romance_ attractive enough; -the special cult which "Our Lady" enjoys in France and Italy is often -associated with this love-story with curious naïveté. Thus, for -example, Paul de Regla (Dr. Desjardin), author of _Jesus of Nazareth -considered from a Scientific, Historical, and Social Standpoint_ -(1894), finds precisely in the illegitimate birth of Christ a special -"title to the halo that irradiates his noble form." - -It seemed to me necessary to enter fully into this important question -of the origin of Christ in the sense of impartial historical science, -because the Church militant itself lays great emphasis on it, and -because it regards the miraculous structure which has been founded -on it as one of its strongest weapons against modern thought. The -highest ethical value of pure primitive Christianity and the ennobling -influence of this "religion of love" on the history of civilization are -quite independent of those mythical dogmas. The so-called "revelations" -on which these myths are based are incompatible with the firmest -results of modern science. - - - - -CHAPTER XVIII - -OUR MONISTIC RELIGION - - Monism as a Connecting Link between Religion and Science--The - _Cultur-Kampf_--The Relations of Church and State--Principles - of the Monistic Religion--Its Three-fold Ideal: the Good, the - True, and the Beautiful--Contradiction between Scientific and - Christian Truth--Harmony of the Monistic and the Christian Idea - of Virtue--Opposition between Monistic and Christian Views - of Art--Modern Expansion and Enrichment of Our Idea of the - World--Landscape-Painting and the Modern Enjoyment of Nature--The - Beauties of Nature--This World and Beyond--Monistic Churches - - -Many distinguished scientists and philosophers of the day, who share -our monistic views, consider that religion is generally played out. -Their meaning is that the clear insight into the evolution of the world -which the great scientific progress of the nineteenth century has -afforded us will satisfy, not only the causal feeling of our reason, -but even our highest emotional cravings. This view is correct in the -sense that the two ideas, religion and science, would indeed blend -into one if we had a perfectly clear and consecutive system of monism. -However, there are but a few resolute thinkers who attain to this most -pure and lofty conception of Spinoza and Goethe. Most of the educated -people of our time (as distinct from the uncultured masses) remain in -the conviction that religion is a separate branch of our mental life, -independent of science, and not less valuable and indispensable. - -If we adopt this view, we can find a means of reconciling the two -great and apparently quite distinct branches in the idea I put forward -in "Monism, as a Connecting-Link between Religion and Science," -in 1892. In the preface to this _Confession of Faith of a Man of -Science_ I expressed myself in the following words with regard to -its double object: "In the first place, I must give expression to -the rational system which is logically forced upon us by the recent -progress of science; it dwells in the intimate thoughts of nearly every -impartial and thoughtful scientist, though few have the courage or -the disposition to avow it. In the second place, I would make of it a -connecting-link between religion and science, and thus do away with -the antithesis which has been needlessly maintained between these two -branches of the highest activity of the human mind. The ethical craving -of our emotion is satisfied by monism no less than the logical demand -for causality on the part of reason." - -The remarkable interest which the discourse enkindled is a proof that -in this monistic profession of faith I expressed the feeling not only -of many scientists, but of a large number of cultured men and women -of very different circles. Not only was I rewarded by hundreds of -sympathetic letters, but by a wide circulation of the printed address, -of which six editions were required within six months. I had the more -reason to be content with this unexpected success, as this "confession -of faith" was originally merely an occasional speech which I delivered -unprepared on October 9, 1892, at Altenburg, during the jubilee of the -Scientific Society of East Germany. Naturally there was the usual -demonstration on the other side; I was fiercely attacked, not only by -the ultramontane press, the sworn defenders of superstition, but also -by the "liberal" controversialists of evangelical Christianity, who -profess to defend both scientific truth and purified faith. In the -seven years that have ensued since that time the great struggle between -modern science and orthodox Christianity has become more threatening; -it has grown more dangerous for science in proportion as Christianity -has found support in an increasing mental and political reaction. In -some countries the Church has made such progress that the freedom -of thought and conscience, which is guaranteed by the laws, is in -practice gravely menaced (for instance, in Bavaria). The great historic -struggle which Draper has so admirably depicted in his _Conflict -between Religion and Science_ is to-day more acute and significant than -ever. For the last twenty-seven years it has been rightly called the -"_cultur-kampf_." - -The famous encyclica and syllabus which the militant pope, Pius IX., -sent out into the entire world in 1864 were a declaration of war on -the whole of modern science; they demanded the blind submission of -reason to the dogmas of the infallible pope. The enormity of this -crude assault on the highest treasures of civilization even roused -many indolent minds from the slumber of belief. Together with the -subsequent promulgation of the papal infallibility (1870), the -encyclica provoked a deep wave of irritation and an energetic repulse -which held out high hopes. In the new German empire, which had attained -its indispensable national unity by the heavy sacrifices of the wars -of 1866 and 1871, the insolent attacks of the pope were felt to be -particularly offensive. On the one hand, Germany is the cradle of -the Reformation and the modern emancipation of reason; on the other -hand, it unfortunately has in its 18,000,000 Catholics a vast host of -militant believers, who are unsurpassed by any other civilized people -in blind obedience to their chief shepherd. - -The dangers of such a situation were clearly recognized by the -great statesman who had solved the political "world-riddle" of the -dismemberment of Germany, and had led us by a marvellous statecraft -to the long-desired goal of national unity and power. Prince Bismarck -began the famous struggle with the Vatican, which is known as the -_cultur-kampf_, in 1872, and it was conducted with equal ability and -energy by the distinguished Minister of Worship, Falk, author of the -May laws of 1873. Unfortunately, Bismarck had to desist six years -afterwards. Although the great statesman was a remarkable judge of men -and a realistic politician of immense tact, he had underestimated the -force of three powerful obstacles--first, the unsurpassed cunning and -unscrupulous treachery of the Roman _curia_; secondly, the correlative -ingratitude and credulity of the uneducated Catholic masses, on which -the papacy built; and, thirdly, the power of apathy, the continuance -of the irrational, simply because it is in possession. Hence, in 1878, -when the abler Leo XIII. had ascended the pontifical throne, the fatal -"To Canossa" was heard once more. From that time the newly established -power of Rome grew in strength; partly through the unscrupulous -intrigues and serpentine bends of its slippery Jesuitical politics, -partly through the false Church-politics of the German government and -the marvellous political incompetence of the German people. We have, -therefore, at the close of the nineteenth century to endure the -pitiful spectacle of the Catholic "Centre" being the most important -section of the Reichstag, and the fate of our humiliated country -depending on a papal party, which does not constitute numerically a -third part of the nation. - -When the _cultur-kampf_ began in 1872, it was justly acclaimed by -all independent thinkers as a political renewal of the Reformation, -a vigorous attempt to free modern civilization from the yoke of -papal despotism. The whole of the Liberal press hailed Bismarck as a -"political Luther"--as the great hero, not only of the national unity, -but also of the rational emancipation of Germany. Ten years afterwards, -when the papacy had proved victorious, the same "Liberal press" changed -its colors, and denounced the _cultur-kampf_ as a great mistake; and -it does the same thing to-day. The facts show how short is the memory -of our journalists, how defective their knowledge of history, and how -poor their philosophic education. The so-called "Peace between Church -and State" is never more than a suspension of hostilities. The modern -papacy, true to the despotic principles it has followed for the last -sixteen hundred years, is determined to wield sole dominion over the -credulous souls of men; it must demand the absolute submission of -the cultured State, which, as such, defends the rights of reason and -science. True and enduring peace there cannot be until one of the -combatants lies powerless on the ground. Either the Church wins, and -then farewell to all "free science and free teaching"--then are our -universities no better than jails, and our colleges become cloistral -schools; or else the modern rational State proves victorious--then, -in the twentieth century, human culture, freedom, and prosperity will -continue their progressive development until they far surpass even the -height of the nineteenth century. - -In order to compass these high aims, it is of the first importance that -modern science not only shatter the false structures of superstition -and sweep their ruins from the path, but that it also erect a new -abode for human emotion on the ground it has cleared--a "palace of -reason," in which, under the influence of our new monistic views, we do -reverence to the real trinity of the nineteenth century--the trinity of -"the true, the good, and the beautiful." In order to give a tangible -shape to the cult of this divine ideal, we must first of all compare -our position with the dominant forms of Christianity, and realize -the changes that are involved in the substitution of the one for the -other. For, in spite of its errors and defects, the Christian religion -(in its primitive and purer form) has so high an ethical value, and -has entered so deeply into the most important social and political -movements of civilized history for the last fifteen hundred years, -that we must appeal as much as possible to its existing institutions -in the establishment of our monistic religion. We do not seek a mighty -_revolution_, but a rational _reformation_, of our religious life. And -just as, two thousand years ago, the classic poetry of the ancient -Greeks incarnated their ideals of virtue in divine shapes, so may -we, too, lend the character of noble goddesses to our three rational -ideals. We must inquire into the features of the three goddesses of the -monist--truth, beauty, and virtue; and we must study their relation -to the three corresponding ideals of Christianity which they are to -replace. - -I. The preceding inquiries (especially those of the first and third -sections) have convinced us that truth unadulterated is only to be -found in the temple of the study of nature, and that the only available -paths to it are critical observation and reflection--the empirical -investigation of facts and the rational study of their efficient -causes. In this way we arrive, by means of pure reason, at true -science, the highest treasure of civilized man. We must, in accordance -with the arguments of our sixteenth chapter, reject what is called -"revelation," the poetry of faith, that affirms the discovery of truth -in a supernatural fashion, without the assistance of reason. And since -the entire structure of the Judæo-Christian religion, like that of the -Mohammedan and the Buddhistic, rests on these so-called revelations, -and these mystic fruits of the imagination directly contradict the -clear results of empirical research, it is obvious that we shall -only attain to a knowledge of the truth by the rational activity of -genuine science, not by the poetic imagining of a mystic faith. In this -respect it is quite certain that the Christian system must give way -to the monistic. The goddess of truth dwells in the temple of nature, -in the green woods, on the blue sea, and on the snowy summits of the -hills--not in the gloom of the cloister, nor in the narrow prisons of -our jail-like schools, nor in the clouds of incense of the Christian -churches. The paths which lead to the noble divinity of truth and -knowledge are the loving study of nature and its laws, the observation -of the infinitely great star-world with the aid of the telescope, and -the infinitely tiny cell-world with the aid of the microscope--not -senseless ceremonies and unthinking prayers, not alms and Peter's -Pence. The rich gifts which the goddess of truth bestows on us are the -noble fruits of the tree of knowledge and the inestimable treasure of a -clear, unified view of the world--not belief in supernatural miracles -and the illusion of an eternal life. - -II. It is otherwise with the divine ideal of eternal goodness. In our -search for the truth we have entirely to exclude the "revelation" of -the churches, and devote ourselves solely to the study of nature; but, -on the other hand, the idea of the good, which we call virtue, in -our monistic religion coincides for the most part with the Christian -idea of virtue. We are speaking, naturally, of the primitive and -pure Christianity of the first three centuries, as far as we learn -its moral teaching from the gospels and the epistles of Paul; it -does not apply to the Vatican caricature of that pure doctrine which -has dominated European civilization, to its infinite prejudice, for -twelve hundred years. The best part of Christian morality, to which we -firmly adhere, is represented by the humanist precepts of charity and -toleration, compassion and assistance. However, these noble commands, -which are set down as "Christian" morality (in its best sense), are by -no means original discoveries of Christianity; they are derived from -earlier religions. The Golden Rule, which sums up these precepts in -one sentence, is centuries older than Christianity. In the conduct of -life this law of natural morality has been followed just as frequently -by non-Christians and atheists as it has been neglected by pious -believers. Moreover, Christian ethics was marred by the great defect -of a narrow insistence on altruism and a denunciation of egoism. Our -monistic ethics lays equal emphasis on the two, and finds perfect -virtue in the just balance of love of self and love of one's neighbor -(cf. chap. xix.). - -III. But monism enters into its strongest opposition to Christianity -on the question of beauty. Primitive Christianity preached the -worthlessness of earthly life, regarding it merely as a preparation -for an eternal life beyond. Hence it immediately followed that all we -find in the life of man here below, all that is beautiful in art and -science, in public and in private life, is of no real value. The true -Christian must avert his eyes from them; he must think only of a worthy -preparation for the life beyond. Contempt of nature, aversion from all -its inexhaustible charms, rejection of every kind of fine art, are -Christian duties; and they are carried out to perfection when a man -separates himself from his fellows, chastises his body, and spends all -his time in prayer in the cloister or the hermit's cell. - -History teaches us that this ascetical morality that would scorn the -whole of nature had, as a natural consequence, the very opposite effect -to that it intended. Monasteries, the homes of chastity and discipline, -soon became dens of the wildest orgies; the sexual commerce of monks -and nuns has inspired shoals of novels, as it is so faithfully depicted -in the literature of the Renaissance. The cult of the "beautiful," -which was then practised, was in flagrant contradiction with the -vaunted "abandonment of the world"; and the same must be said of the -pomp and luxury which soon developed in the immoral private lives of -the higher ecclesiastics and in the artistic decoration of Christian -churches and monasteries. - -It may be objected that our view is refuted by the splendor of -Christian art, which, especially in the best days of the Middle Ages, -created works of undying beauty. The graceful Gothic cathedrals and -Byzantine basilicas, the hundreds of magnificent chapels, the thousands -of marble statues of saints and martyrs, the millions of fine pictures -of saints, of profoundly conceived representations of Christ and the -madonna--all are proofs of the development of a noble art in the Middle -Ages, which is unique of its kind. All these splendid monuments of -mediæval art are untouched in their high æsthetic value, whatever we -say of their mixture of truth and fancy. Yes; but what has all that -to do with the pure teaching of Christianity--with that religion of -sacrifice that turned scornfully away from all earthly parade and -glamour, from all material beauty and art; that made light of the life -of the family and the love of woman; that urged an exclusive concern as -to the immaterial goods of eternal life? The idea of a Christian art -is a contradiction in terms--a _contradictio in adjecto_. The wealthy -princes of the Church who fostered it were candidly aiming at very -different ideals, and they completely attained them. In directing the -whole interest and activity of the human mind in the Middle Ages to the -Christian Church and its distinctive art they were diverting it _from -nature_ and from the knowledge of the treasures that were hidden in it, -and would have conducted to independent science. Moreover, the daily -sight of the huge images of the saints and of the scenes of "sacred -history" continually reminded the faithful of the vast collection of -myths that the Church had made. The legends themselves were taught -and believed to be true narratives, and the stories of miracles to be -records of actual events. It cannot be doubted that in this respect -Christian art has exercised an immense influence on general culture, -and especially in the strengthening of Christian belief--an influence -which still endures throughout the entire civilized world. - -The diametrical opposite of this dominant Christian art is the new -artistic tendency which has been developed during the present century -in connection with science. The remarkable expansion of our knowledge -of nature, and the discovery of countless beautiful forms of life, -which it includes, have awakened quite a new æsthetic sense in our -generation, and thus given a new tone to painting and sculpture. -Numerous scientific voyages and expeditions for the exploration -of unknown lands and seas, partly in earlier centuries, but more -especially in the nineteenth, have brought to light an undreamed -abundance of new organic forms. The number of new species of animals -and plants soon became enormous, and among them (especially among the -lower groups that had been neglected before) there were thousands -of forms of great beauty and interest, affording an entirely new -inspiration for painting, sculpture, architecture, and technical -art. In this respect a new world was revealed by the great advance -of microscopic research in the second half of the century, and -especially by the discovery of the marvellous inhabitants of the -deep sea, which were first brought to light by the famous expedition -of the _Challenger_ (1872-76). Thousands of graceful radiolaria and -thalamophora, of pretty medusæ and corals, of extraordinary molluscs, -and crabs, suddenly introduced us to a wealth of hidden organisms -beyond all anticipation, the peculiar beauty and diversity of which -far transcend all the creations of the human imagination. In the -fifty large volumes of the account of the _Challenger_ expedition a -vast number of these beautiful forms are delineated on three thousand -plates; and there are millions of other lovely organisms described in -other great works that are included in the fast-growing literature of -zoology and botany of the last ten years. I began on a small scale to -select a number of these beautiful forms for more popular description -in my _Art Forms in Nature_ (1899). - -However, there is now no need for long voyages and costly works to -appreciate the beauties of this world. A man needs only to keep his -eyes open and his mind disciplined. Surrounding nature offers us -everywhere a marvellous wealth of lovely and interesting objects of all -kinds. In every bit of moss and blade of grass, in every beetle and -butterfly, we find, when we examine it carefully, beauties which are -usually overlooked. Above all, when we examine them with a powerful -glass or, better still, with a good microscope, we find everywhere in -nature a new world of inexhaustible charms. - -But the nineteenth century has not only opened our eyes to the æsthetic -enjoyment of the microscopic world; it has shown us the beauty of -the greater objects in nature. Even at its commencement it was the -fashion to regard the mountains as magnificent but forbidding, and -the sea as sublime but dreaded. At its close the majority of educated -people--especially they who dwell in the great cities--are delighted -to enjoy the glories of the Alps and the crystal splendor of the -glacier world for a fortnight every year, or to drink in the majesty -of the ocean and the lovely scenery of its coasts. All these sources -of the keenest enjoyment of nature have only recently been revealed -to us in all their splendor, and the remarkable progress we have -made in facility and rapidity of conveyance has given even the less -wealthy an opportunity of approaching them. All this progress in the -æsthetic enjoyment of nature--and, proportionately, in the scientific -understanding of nature--implies an equal advance in higher mental -development and, consequently, in the direction of our monistic -religion. - -The opposite character of our _naturalistic_ century to that of the -_anthropistic_ centuries that preceded is especially noticeable in -the different appreciation and spread of illustrations of the most -diverse natural objects. In our own days a lively interest in artistic -work of that kind has been developed, which did not exist in earlier -ages; it has been supported by the remarkable progress of commerce -and technical art which have facilitated a wide popularization of -such illustrations. Countless illustrated periodicals convey along -with their general information a sense of the inexhaustible beauty of -nature in all its departments. In particular, landscape-painting has -acquired an importance that surpassed all imagination. In the first -half of the century one of our greatest and most erudite scientists, -Alexander Humboldt, had pointed out that the development of modern -landscape-painting is not only of great importance as an incentive -to the study of nature and as a means of geographical description, -but that it is to be commended in other respects as a noble educative -medium. Since that time the taste for it has considerably increased. -It should be the aim at every school to teach the children to enjoy -scenery at an early age, and to give them the valuable art of -imprinting on the memory by a drawing or water-color sketch. - -The infinite wealth of nature in what is beautiful and sublime offers -every man with open eyes and an æsthetic sense an incalculable sum of -choicest gifts. Still, however valuable and agreeable is the immediate -enjoyment of each single gift, its worth is doubled by a knowledge of -its meaning and its connection with the rest of nature. When Humboldt -gave us the "outline of a physical description of the world" in his -magnificent _Cosmos_ forty years ago, and when he combined scientific -and æsthetic consideration so happily in his standard _Prospects of -Nature_, he justly indicated how closely the higher enjoyment of nature -is connected with the "scientific establishment of cosmic laws," and -that the conjunction of the two serves to raise human nature to a -higher stage of perfection. The astonishment with which we gaze upon -the starry heavens and the microscopic life in a drop of water, the awe -with which we trace the marvellous working of energy in the motion of -matter, the reverence with which we grasp the universal dominance of -the law of substance throughout the universe--all these are part of our -emotional life, falling under the heading of "natural religion." - -This progress of modern times in knowledge of the true and enjoyment -of the beautiful expresses, on the one hand, a valuable element of our -monistic religion, but is, on the other hand, in fatal opposition to -Christianity. For the human mind is thus made to live on this side of -the grave; Christianity would have it ever gaze beyond. Monism teaches -that we are perishable children of the earth, who for one or two, -or, at the most, three generations, have the good fortune to enjoy -the treasures of our planet, to drink of the inexhaustible fountain -of its beauty, and to trace out the marvellous play of its forces. -Christianity would teach us that the earth is "a vale of tears," in -which we have but a brief period to chasten and torment ourselves in -order to merit the life of eternal bliss beyond. Where this "beyond" -is, and of what joys the glory of this eternal life is compacted, no -revelation has ever told us. As long as "heaven" was thought to be the -blue vault that hovers over the disk of our planet, and is illumined -by the twinkling light of a few thousand stars, the human imagination -could picture to itself the ambrosial banquets of the Olympic gods -above or the laden tables of the happy dwellers in Valhalla. But now -all these deities and the immortal souls that sat at their tables are -"houseless and homeless," as David Strauss has so ably described; for -we know from astrophysical science that the immeasurable depths of -space are filled with a prosaic ether, and that millions of heavenly -bodies, ruled by eternal laws of iron, rush hither and thither in the -great ocean, in their eternal rhythm of life and death. - -The places of devotion, in which men seek the satisfaction of their -religious emotions and worship the objects of their reverence, are -regarded as sacred "churches." The pagodas of Buddhistic Asia, the -Greek temples of classical antiquity, the synagogues of Palestine, -the mosques of Egypt, the Catholic cathedrals of the south, and the -Protestant cathedrals of the north, of Europe--all these "houses of -God" serve to raise man above the misery and the prose of daily life, -to lift him into the sacred, poetic atmosphere of a higher, ideal -world. They attain this end in a thousand different ways, according -to their various forms of worship and their age. The modern man who -"has science and art"--and, therefore, "religion"--needs no special -church, no narrow, enclosed portion of space. For through the length -and breadth of free nature, wherever he turns his gaze, to the whole -universe or to any single part of it, he finds, indeed, the grim -"struggle for life," but by its side are ever "the good, the true, and -the beautiful"; his church is commensurate with the whole of glorious -nature. Still, there will always be men of special temperament who will -desire to have decorated temples or churches as places of devotion -to which they may withdraw. Just as the Catholics had to relinquish a -number of churches to the Reformation in the sixteenth century, so a -still larger number will pass over to "free societies" of monists in -the coming years. - - - - -CHAPTER XIX - -OUR MONISTIC ETHICS - - Monistic and Dualistic Ethics--Contradiction of Pure and - Practical Reason in Kant--His Categorical Imperative--The - Neo-Kantians--Herbert Spencer--Egoism and Altruism--Equivalence - of the Two Instincts--The Fundamental Law of Ethics: the Golden - Rule--Its Antiquity--Christian Ethics--Contempt of Self, the - Body, Nature, Civilization, the Family, Woman--Roman Catholic - Ethics--Immoral Results of Celibacy--Necessity for the Abolition of - the Law of Celibacy, Oral Confession, and Indulgences--State and - Church--Religion a Private Concern--Church and School--State and - School--Need of School Reform - - -The practical conduct of life makes a number of definite ethical claims -on a man which can only be duly and naturally satisfied when they are -in complete harmony with his view of the world. In accordance with this -fundamental principle of our monistic philosophy, our whole system of -ethics must be rationally connected with the unified conception of the -cosmos which we have formed by our advanced knowledge of the laws of -nature. Just as the infinite universe is one great whole in the light -of our monistic teaching, so the spiritual and moral life of man is -a part of this cosmos, and our naturalistic ordering of it must also -be monistic. There are not two different, separate worlds--the one -physical and material, and the other moral and immaterial. - -The great majority of philosophers and theologians still hold the -contrary opinion. They affirm, with Kant, that the moral world is quite -independent of the physical, and is subject to very different laws; -hence a man's conscience, as the basis of his moral life, must also be -quite independent of our scientific knowledge of the world, and must be -based rather on his religious faith. On that theory the study of the -moral world belongs to _practical_ reason, while that of nature, or of -the physical world, is referred to _pure_ or theoretical reason. This -unequivocal and conscious dualism of Kant's philosophy was its greatest -defect; it has caused, and still causes, incalculable mischief. First -of all the "critical Kant" had built up the splendid and marvellous -palace of pure reason, and convincingly proved that the three great -central dogmas of metaphysics--a personal God, free will, and the -immortal soul--had no place whatever in it, and that no rational proof -could be found of their reality. Afterwards, however, the "dogmatic -Kant" superimposed on this true crystal palace of _pure_ reason the -glittering, ideal castle in the air of _practical_ reason, in which -three imposing church-naves were designed for the accommodation of -those three great mystic divinities. When they had been put out at the -front door by rational knowledge they returned by the back door under -the guidance of irrational faith. - -The cupola of his great cathedral of faith was crowned by Kant with his -curious idol, the famous "categorical imperative." According to it, -the demand of the universal moral law is unconditional, independent of -any regard to actuality or potentiality. It runs: "Act at all times in -such wise that the maxim (or the subjective law of thy will) may hold -good as a principle of a universal law." On that theory all normal men -would have the same sense of duty. Modern anthropology has ruthlessly -dissipated that pretty dream; it has shown that conceptions of duty -differ even more among uncivilized than among civilized nations. All -the actions and customs which we regard as sins or loathsome crimes -(theft, fraud, murder, adultery, etc.) are considered by other nations -in certain circumstances to be virtues, or even sacred duties. - -Although the obvious contradiction of the two forms of reason in Kant's -teaching, the fundamental antagonism of pure and practical reason, was -recognized and attacked at the very beginning of the century, it is -still pretty widely accepted. The modern school of neo-Kantians urges a -"return to Kant" so pressingly precisely on account of this agreeable -dualism; the Church militant zealously supports it because it fits -in admirably with its own mystic faith. But it met with an effective -reverse at the hands of modern science in the second half of the -nineteenth century, which entirely demolished the theses of the system -of practical reason. Monistic cosmology proved, on the basis of the law -of substance, that there is no personal God; comparative and genetic -psychology showed that there cannot be an immortal soul; and monistic -physiology proved the futility of the assumption of "free will." -Finally, the science of evolution made it clear that the same eternal -iron laws that rule in the inorganic world are valid too in the organic -and moral world. - -But modern science gives not only a negative support to practical -philosophy and ethics in demolishing the Kantian dualism, but it -renders the positive service of substituting for it the new structure -of ethical monism. It shows that the feeling of duty does not rest -on an illusory "categorical imperative," but on the solid ground of -_social instinct_, as we find in the case of all social animals. It -regards as the highest aim of all morality the re-establishment of a -sound harmony between egoism and altruism, between self-love and the -love of one's neighbor. It is to the great English philosopher, Herbert -Spencer, that we owe the founding of this monistic ethics on a basis of -evolution. - -Man belongs to the social vertebrates, and has, therefore, like all -social animals, two sets of duties--first to himself, and secondly -to the society to which he belongs. The former are the behests of -self-love or egoism, the latter of love for one's fellows or altruism. -The two sets of precepts are equally just, equally natural, and equally -indispensable. If a man desire to have the advantage of living in an -organized community, he has to consult not only his own fortune, but -also that of the society, and of the "neighbors" who form the society. -He must realize that its prosperity is his own prosperity, and that it -cannot suffer without his own injury. This fundamental law of society -is so simple and so inevitable that one cannot understand how it can be -contradicted in theory or in practice; yet that is done to-day, and has -been done for thousands of years. - -The equal appreciation of these two natural impulses, or the moral -equivalence of self-love and love of others, is the chief and the -fundamental principle of our morality. Hence the highest aim of all -ethics is very simple--it is the re-establishment of "the natural -equality of egoism and altruism, of the love of one's self and the -love of one's neighbor." The Golden Rule says: "Do unto others as you -would that they should do unto you." From this highest precept of -Christianity it follows of itself that we have just as sacred duties -towards ourselves as we have towards our fellows. I have explained -my conception of this principle in my _Monism_, and laid down three -important theses. (1) Both these concurrent impulses are natural -laws, of equal importance and necessity for the preservation of the -family and the society; egoism secures the self-preservation of the -individual, altruism that of the species which is made up of the chain -of perishable individuals. (2) The social duties which are imposed -by the social structure of the associated individuals, and by means -of which it secures its preservation, are merely higher evolutionary -stages of the social instincts, which we find in all higher social -animals (as "habits which have become hereditary"). (3) In the case of -civilized man all ethics, theoretical or practical, being "a science -of rules," is connected with his view of the world at large, and -consequently with his religion. - -From the recognition of the fundamental principle of our morality -we may immediately deduce its highest precept, that noble command, -which is often called the Golden Rule of morals, or, briefly, the -Golden Rule. Christ repeatedly expressed it in the simple phrase: -"Thou shalt love thy neighbor as thyself." Mark adds that "there is -no greater commandment than this," and Matthew says: "In these two -commandments is the whole law and the prophets." In this greatest and -highest commandment our monistic ethics is completely at one with -Christianity. We must, however, recall the historical fact that the -formulation of this supreme command is not an original merit of Christ, -as the majority of Christian theologians affirm and their uncritical -supporters blindly accept. The Golden Rule is five hundred years -older than Christ; it was laid down as the highest moral principle by -many Greek and Oriental sages. Pittacus, of Mylene, one of the seven -wise men of Greece, said six hundred and twenty years before Christ: -"Do not that to thy neighbor that thou wouldst not suffer from him." -Confucius, the great Chinese philosopher and religious founder (who -rejected the idea of a personal God and of the immortality of the -soul), said five hundred years B.C.: "Do to every man as thou wouldst -have him do to thee; and do not to another what thou wouldst not have -him do to thee. This precept only dost thou need; it is the foundation -of all other commandments." Aristotle taught about the middle of the -fourth century B.C.: "We must act towards others as we wish others -to act towards us." In the same sense, and partly in the same words, -the Golden Rule was given by Thales, Isocrates, Aristippus, Sextus, -the Pythagorean, and other philosophers of classic antiquity--several -centuries before Christ. From this collection it is clear that the -Golden Rule had a _polyphyletic_ origin--that is, it was formulated by -a number of philosophers at different times and in different places, -quite independently of each other. Otherwise it must be assumed that -Jesus derived it from some other Oriental source, from ancient Semitic, -Indian, Chinese, or especially Buddhistic traditions, as has been -proved in the case of most of the other Christian doctrines. - -As the great ethical principle is thus twenty-five hundred years old, -and as Christianity itself has put it at the head of its moral teaching -as the highest and all-embracing commandment, it follows that our -monistic ethics is in complete harmony on this important point, not -only with the ethics of the ancient heathens, but also with that of -Christianity. Unfortunately this harmony is disturbed by the fact that -the gospels and the Pauline epistles contain many other points of moral -teaching, which contradict our first and supreme commandment. Christian -theologians have fruitlessly striven to explain away these striking -and painful contradictions by their ingenious interpretations. We need -not enter into that question now, but we must briefly consider those -unfortunate aspects of Christian ethics which are incompatible with the -better thought of the modern age, and which are distinctly injurious -in their practical consequences. Of that character is the contempt -which Christianity has shown for self, for the body, for nature, for -civilization, for the family, and for woman. - -I. The supreme mistake of Christian ethics, and one which runs -directly counter to the Golden Rule, is its exaggeration of love of -one's neighbor at the expense of self-love. Christianity attacks and -despises egoism on principle. Yet that natural impulse is absolutely -indispensable in view of self-preservation; indeed, one may say that -even altruism, its apparent opposite, is only an enlightened egoism. -Nothing great or elevated has ever taken place without egoism, and -without the passion that urges us to great sacrifices. It is only -the excesses of the impulse that are injurious. One of the Christian -precepts that were impressed upon us in our early youth as of great -importance, and that are glorified in millions of sermons, is: "Love -your enemies, bless them that curse you, do good to them that hate you, -and pray for them which despitefully use you and persecute you." It is -a very ideal precept, but as useless in practice as it is unnatural. -So it is with the counsel, "If any man will take away thy coat, let -him have thy cloak also." Translated into the terms of modern life, -that means: "When some unscrupulous scoundrel has defrauded thee of -half thy goods, let him have the other half also." Or, again, in the -language of modern politics: "When the pious English take from you -simple Germans one after another of your new and valuable colonies in -Africa, let them have all the rest of your colonies also--or, best of -all, give them Germany itself." And, while we touch on the marvellous -world-politics of modern England, we may note in passing its direct -contradiction of every precept of Christian charity, which is more -frequently on the lips of that great nation than of any other nation in -the world. However, the glaring contradiction between the theoretical, -_ideal_, altruistic morality of the human individual and the _real_, -purely selfish morality of the human community, and especially of the -civilized Christian state, is a familiar fact. It would be interesting -to determine mathematically in what proportion among organized men the -altruistic ethical ideal of the individual changes into its contrary, -the purely egoistic "real politics" of the state and the nation. - -II. Since the Christian faith takes a wholly dualistic view of the -human organism and attributes to the immortal soul only a temporary -sojourn in the mortal frame, it very naturally sets a much greater -value on the soul than on the body. Hence results that neglect of the -care of the body, of training, and of cleanliness which contrasts the -life of the Christian Middle Ages so unfavorably with that of pagan -classical antiquity. Christian ethics contains none of those firm -commands as to daily ablutions which are theoretically laid down and -practically fulfilled in the Mohammedan, Hindoo, and other religions. -In many monasteries the ideal of the pious Christian is the man who -does not wash and clothe himself properly, who never changes his -malodorous gown, and who, instead of regular work, fills up his useless -life with mechanical prayers, senseless fasts, and so forth. As a -special outgrowth of this contempt of the body we have the disgusting -discipline of the flagellants and other ascetics. - -III. One source of countless theoretical errors and practical -blemishes, of deplorable crudity and privation, is found in the false -anthropism of Christianity--that is, in the unique position which -it gives to man, as the image of God, in opposition to all the rest -of nature. In this way it has contributed, not only to an extremely -injurious isolation from our glorious mother "nature," but also to -a regrettable contempt of all other organisms. Christianity has no -place for that well-known love of animals, that sympathy with the -nearly related and friendly mammals (dogs, horses, cattle, etc.), -which is urged in the ethical teaching of many of the older religions, -especially Buddhism. Whoever has spent much time in the south of Europe -must have often witnessed those frightful sufferings of animals which -fill us friends of animals with the deepest sympathy and indignation. -And when one expostulates with these brutal "Christians" on their -cruelty, the only answer is, with a laugh: "But the beasts are not -Christians." Unfortunately Descartes gave some support to the error in -teaching that man only has a sensitive soul, not the animal. - -How much more elevated is our monistic ethics than the Christian in -this regard! Darwinism teaches us that we have descended immediately -from the primates, and, in a secondary degree, from a long series -of earlier mammals, and that, therefore, they are "our brothers"; -physiology informs us that they have the same nerves and sense-organs -as we, and the same feelings of pleasure and pain. No sympathetic -monistic scientist would ever be guilty of that brutal treatment of -animals which comes so lightly to the Christian in his anthropistic -illusion--to the "child of the God of love." Moreover, this Christian -contempt of nature on principle deprives man of an abundance of the -highest earthly joys, especially of the keen, ennobling enjoyment of -nature. - -IV. Since, according to Christ's teaching, our planet is "a vale of -tears," and our earthly life is valueless and a mere preparation for a -better life to come, it has succeeded in inducing men to sacrifice all -happiness on this side of eternity and make light of all earthly goods. -Among these "earthly goods," in the case of the modern civilized man, -we must include the countless great and small conveniences of technical -science, hygiene, commerce, etc., which have made modern life cheerful -and comfortable; we must include all the gratifications of painting, -sculpture, music, and poetry, which flourished exceedingly even during -the Middle Ages (in spite of its principles), and which we esteem -as "ideal pleasures"; we must include all that invaluable progress -of science, especially the study of nature, of which the nineteenth -century is justly proud. All these "earthly goods," that have so high a -value in the eyes of the monist, are worthless--nay, injurious--for the -most part, according to Christian teaching; the stern code of Christian -morals should look just as unfavorably on the pursuit of these -pleasures as our humanistic ethics fosters and encourages it. Once -more, therefore, Christianity is found to be an enemy to civilization, -and the struggle which modern thought and science are compelled to -conduct with it is, in this additional sense, a "_cultur-kampf_." - -V. Another of the most deplorable aspects of Christian morality is -its belittlement of the life of the family, of that natural living -together with our next of kin which is just as necessary in the case -of man as in the case of all the higher social animals. The family -is justly regarded as the "foundation of society," and the healthy -life of the family is a necessary condition of the prosperity of the -State. Christ, however, was of a very different opinion: with his gaze -ever directed to "the beyond," he thought as lightly of woman and the -family as of all other goods of "this life." Of his infrequent contact -with his parents and sisters the gospels have very little to say; but -they are far from representing his relations with his mother to have -been so tender and intimate as they are poetically depicted in so many -thousands of pictures. He was not married himself. Sexual love, the -first foundation of the family union, seems to have been regarded by -Jesus as a necessary evil. His most enthusiastic apostle, Paul, went -still farther in the same direction, declaring it to be better not to -marry than to marry: "It is good for a man not to touch a woman." If -humanity were to follow this excellent counsel, it would soon be rid -of all earthly misery and suffering: it would be killed off by such a -"radical cure" within half a century. - -VI. As Christ never knew the love of woman, he had no personal -acquaintance with that refining of man's true nature that comes only -from the intimate life of man with woman. The intimate sexual union, on -which the preservation of the human race depends, is just as important -on that account as the spiritual penetration of the two sexes, or -the mutual complement which they bring to each other in the practical -wants of daily life as well as in the highest ideal functions of the -soul. For man and woman are two different organisms, equal in worth, -each having its characteristic virtues and defects. As civilization -advanced, this ideal value of sexual love was more appreciated, and -woman held in higher honor, especially among the Teutonic races; she -is the inspiring source of the highest achievements of art and poetry. -But Christ was as far from this view as nearly the whole of antiquity; -he shared the idea that prevailed everywhere in the East--that -woman is subordinate to man, and intercourse with her is "unclean." -Long-suffering nature has taken a fearful revenge for this blunder; its -sad consequences are written in letters of blood in the history of the -papal Middle Ages. - -The marvellous hierarchy of the Roman Church, that never disdained any -means of strengthening its spiritual despotism, found an exceptionally -powerful instrument in the manipulation of this "unclean" idea, and in -the promotion of the ascetic notion that abstinence from intercourse -with women is a virtue of itself. In the first few centuries after -Christ a number of priests voluntarily abstained from marriage, and -the supposed value of this celibacy soon rose to such a degree that it -was made obligatory. In the Middle Ages the seduction of women of good -repute and of their daughters by Catholic priests (the confessional -was an active agency in the business) was a public scandal: many -communities, in order to prevent such things, pressed for a license -of concubinage to be given to the clergy. And it was done in many, -and sometimes very romantic, ways. Thus, for instance, the canon law -that the priest's cook should not be less than forty years old was -very cleverly "explained" in the sense that the priest might have two -cooks, one in the presbytery, another without; if one was twenty-four -and the other eighteen, that made forty-two together--two years above -the prescribed age. At the Christian councils, at which heretics were -burned alive, the cardinals and bishops sat down with whole troops -of prostitutes. The private and public debauchery of the Catholic -clergy was so scandalous and dangerous to the commonwealth that there -was a general rebellion against it before the time of Luther, and a -loud demand for a "reformation of the church in head and members." It -is well known that these immoral relations still continue in Roman -Catholic lands, although more in secret. Formerly proposals were -made from time to time for the definitive abrogation of celibacy, as -was done, for instance, in the chambers of Baden, Bavaria, Hesse, -Saxony, and other lands; but they have, unfortunately, hitherto proved -unavailing. In the German Reichstag, in which the ultramontane Centre -is now proposing the most ridiculous measures for the suppression of -sexual immorality, there is now no party that will urge the abolition -of celibacy in the interest of public morality. The so-called -"Freethought" Party and the utopian social democracy coquette with the -favor of the Centre. - -The modern state that would lift not only the material, but the moral, -life of its people to a higher level is entitled, and indeed bound, -to sweep away such unworthy and harmful conditions. The obligatory -celibacy of the Catholic clergy is as pernicious and immoral as the -practice of auricular confession or the sale of indulgences. All -three have nothing whatever to do with primitive Christianity. All -three are directly opposed to true Christian morality. All three are -disreputable inventions of the papacy, designed for the sole purpose of -strengthening its despotic rule over the credulous masses and making as -much material profit as possible out of them. - -The Nemesis of history will sooner or later exact a terrible account -of the Roman papacy, and the millions who have been robbed of their -happiness by this degenerate religion will help to give it its -death-blow in the coming twentieth century--at least, in every truly -civilized state. It has been recently calculated that the number of -men who lost their lives in the papal persecutions of heretics, the -Inquisition, the Christian religious wars, etc., is much more than -ten millions. But what is this in comparison with the tenfold greater -number of the unfortunate _moral_ victims of the institutions and -the priestly domination of the degenerate Christian Church--with the -unnumbered millions whose higher mental life was extinguished, whose -conscience was tortured, whose family life was destroyed, by the -Church? We may with truth apply the words of Goethe in his _Bride of -Corinth_: - - "Victims fall, nor lambs nor bulls, - But human victims numberless." - -In the great _cultur-kampf_, which must go on as long as these sad -conditions exist, the first aim must be the absolute separation of -Church and State. There shall be "a free Church in a free State"--that -is, every Church shall be free in the practice of its special worship -and ceremonies, and in the construction of its fantastic poetry and -superstitious dogmas--with the sole condition that they contain no -danger to social order or morality. Then there will be equal rights -for all. Free societies and monistic religious bodies shall be equally -tolerated, and just as free in their movements as Liberal Protestant -and orthodox ultramontane congregations. But for all these "faithful" -of the most diverse sects religion will have to be a private concern. -The state shall supervise them, and prevent excesses; but it must -neither oppress nor support them. Above all, the ratepayers shall not -be compelled to contribute to the support and spread of a "faith" which -they honestly believe to be a harmful superstition. In the United -States such a complete separation of Church and State has been long -accomplished, greatly to the satisfaction of all parties. They have -also the equally important separation of the Church from the school; -that is, undoubtedly, a powerful element in the great advance which -science and culture have recently made in America. - -It goes without saying that this exclusion of the Church from the -school only refers to its sectarian principles, the particular form -of belief which each Church has evolved in the course of its life. -This sectarian education is purely a private concern, and should be -left to parents and tutors, or to such priests or teachers as may -have the personal confidence of the parents. Instead of the rejected -sectarian instruction, two important branches of education will be -introduced--monistic or humanist ethics and comparative religion. -During the last thirty years an extensive literature has appeared -dealing with the new system of ethics which has been raised on the -basis of modern science--especially evolutionary science. Comparative -religion will be a natural companion to the actual elementary -instruction in "biblical history" and in the mythology of Greece and -Rome. Both of these will remain in the curriculum. The reason for -that is obvious enough; the whole of our painting and sculpture, the -chief branches of monistic æsthetics, are intimately blended with -the Christian, Greek, and Roman mythologies. There will only be this -important difference--that the Christian myths and legends will not -be taught as truths, but as poetic fancies, like the Greek and Roman -myths; the high value of the ethical and æsthetical material they -contain will not be lessened, but increased, by this means. As regards -the Bible, the "book of books" will only be given to the children in -carefully selected extracts (a sort of "school Bible"); in this way we -shall avoid the besmirching of the child's imagination with the unclean -stories and passages which are so numerous in the Old Testament. - -Once the modern State has freed itself and its schools from the -fetters of the Church, it will be able to devote more attention to the -improvement of education. The incalculable value of a good system of -education has forced itself more and more upon us as the many aspects -of modern civilized life have been enlarged and enriched in the -course of the century. But the development of the educational methods -has by no means kept pace with life in general. The necessity for a -comprehensive reform of our schools is making itself felt more and -more. On this question, too, a number of valuable works have appeared -in the course of the last forty years. We shall restrict ourselves to -making a few general observations which we think of special importance. - -1. In all education up to the present time _man_ has played the chief -part, and especially the grammatical study of his language; the study -of _nature_ was entirely neglected. - -2. In the school of the future nature will be the chief object of the -study; a man shall learn a correct view of the world he lives in; he -will not be made to stand outside of and opposed to nature, but be -represented as its highest and noblest product. - -3. The study of the classical tongues (Latin and Greek), which has -hitherto absorbed most of the pupils' time and energy, is indeed -valuable; but it will be much restricted, and confined to the mere -elements (obligatory for Latin, optional for Greek). - -4. In consequence, modern languages must be all the more cultivated in -all the higher schools (English and French to be obligatory, Italian -optional). - -5. Historical instruction must pay more attention to the inner -mental and spiritual life of a nation, and to the development of its -civilization, and less to its external history (the vicissitudes of -dynasties, wars, and so forth). - -6. The elements of evolutionary science must be learned in conjunction -with cosmology, geology must go with geography, and anthropology with -biology. - -7. The first principles of biology must be familiar to every educated -man; the modern training in observation furnishes an attractive -introduction to the biological sciences (anthropology, zoology, and -botany). A start must be made with descriptive system (in conjunction -with ætiology or bionomy); the elements of anatomy and physiology to be -added later on. - -8. The first principles of physics and chemistry must also be taught, -and their exact establishment with the aid of mathematics. - -9. Every pupil must be taught to draw well, and from nature; and, -wherever it is possible, the use of water-colors. The execution of -drawings and of water-color sketches from nature (of flowers, animals, -landscapes, clouds, etc.) not only excites interest in nature and helps -memory to enjoy objects, but it gives the pupil his first lesson in -_seeing_ correctly and understanding what he has seen. - -10. Much more care and time must be devoted than has been done hitherto -to corporal exercise, to gymnastics and swimming; but it is especially -important to have walks in common every week, and journeys on foot -during the holidays. The lesson in observation which they obtain in -this way is invaluable. - -The chief aim of higher education up to the present time, in most -countries, has been a preparation for the subsequent profession, and -the acquisition of a certain amount of information and direction -for civic duties. The school of the twentieth century will have for -its main object the formation of independent thought, the clear -understanding of the knowledge acquired, and an insight into the -natural connection of phenomena. If the modern state gives every -citizen a vote, it should also give him the means of developing his -reason by a proper education, in order to make a rational use of his -vote for the commonweal. - - - - -CHAPTER XX - -SOLUTION OF THE WORLD-PROBLEMS - - A Glance at the Progress of the Nineteenth Century in Solving - Cosmic Problems--I. Progress of Astronomy and Cosmology--Physical - and Chemical Unity of the Universe--Cosmic Metamorphoses--Evolution - of the Planetary System--Analogy of the Phylogenetic Processes - on the Earth and on Other Planets--Organic Inhabitants of - Other Heavenly Bodies--Periodic Variation in the Making of - Worlds--II. Progress of Geology and Palæontology--Neptunism and - Vulcanism--Theory of Continuity--III. Progress of Physics and - Chemistry--IV. Progress of Biology--Cellular Theory and Theory of - Descent--V. Anthropology--Origin of Man--General Conclusion - - -At the close of our philosophic study of the riddles of the universe -we turn with confidence to the answer to the momentous question, How -nearly have we approached to a solution of them? What is the value of -the immense progress which the passing nineteenth century has made in -the knowledge of nature? And what prospect does it open out to us for -the future, for the further development of our system in the twentieth -century, at the threshold of which we pause? Every unprejudiced thinker -who impartially considers the solid progress of our empirical science, -and the unity and clearness of our philosophic interpretation of it, -will share our view: the nineteenth century has made greater progress -in knowledge of the world and in grasp of its nature than all its -predecessors; it has solved many great problems that seemed insoluble a -hundred years ago; it has opened out to us new provinces of learning, -the very existence of which was unsuspected at the beginning of the -century. Above all, it has put clearly before our eyes the lofty aim of -monistic cosmology, and has pointed out the path which alone will lead -us towards it--the way of the exact empirical investigation of facts, -and of the critical genetic study of their causes. The great abstract -law of mechanical causality, of which our cosmological law--the law -of substance--is but another and a concrete expression, now rules -the entire universe, as it does the mind of man; it is the steady, -immovable pole-star, whose clear light falls on our path through the -dark labyrinth of the countless separate phenomena. To see the truth -of this more clearly, let us cast a brief glance at the astonishing -progress which the chief branches of science have made in this -remarkable period. - - -I.--PROGRESS OF ASTRONOMY - -The study of the heavens is the oldest, the study of man the youngest, -of the sciences. With regard to himself and the character of his being -man only obtained a clear knowledge in the second half of the present -century; with regard to the starry heavens, the motions of the planets, -and so on, he had acquired astonishing information forty-five hundred -years ago. The ancient Chinese, Hindoos, Egyptians, and Chaldæans in -the distant East knew more of the science of the spheres than the -majority of educated Christians did in the West four thousand years -after them. An eclipse of the sun was astronomically observed in China -in the year 2697 B.C., and the plane of the ecliptic was determined -by means of a gnome eleven hundred years B.C., while Christ himself -had no knowledge whatever of astronomy--indeed, he looked out upon -heaven and earth, nature and man, from the very narrowest geocentric -and anthropocentric point of view. The greatest advance of astronomy -is generally, and rightly, said to be the founding of the heliocentric -system of Copernicus, whose famous work, _De Revolutionibus Orbium -Celestium_, of itself caused a profound revolution in the minds of -thoughtful men. In overthrowing the Ptolemaic system, he destroyed the -foundation of the Christian theory, which regarded the earth as the -centre of the universe and man as the godlike ruler of the earth. It -was natural, therefore, that the Christian clergy, with the pope at its -head, should enter upon a fierce struggle with the invaluable discovery -of Copernicus. Yet it soon cleared a path for itself, when Kepler and -Galileo grounded on it their true "mechanics of the heavens," and -Newton gave it a solid foundation by his theory of gravitation (1686). - -A further great advance, comprehending the entire universe, was the -application of the idea of evolution to astronomy. It was done by -the youthful Kant in 1755; in his famous general natural history and -theory of the heavens he undertook the discussion, not only of the -"constitution," but also of the "mechanical origin" of the whole -world-structure on Newtonian principles. The splendid _Système du -Monde_ of Laplace, who had independently come to the same conclusions -as Kant on the world-problem, gave so firm a basis to this new -_Mécanique Céleste_ in 1796 that it looked as if nothing entirely -new of equal importance was left to be discovered in the nineteenth -century. Yet here again it had the honor of opening out entirely -new paths and infinitely enlarging our outlook on the universe. The -invention of photography and photometry, and especially of spectral -analysis (in 1860 by Bunsen and Kirchoff), introduced physics and -chemistry into astronomy and led to cosmological conclusions of the -utmost importance. It was now made perfectly clear that matter is -the same throughout the universe, and that its physical and chemical -properties in the most distant stars do not differ from those of the -earth under our feet. - -The monistic conviction, which we thus arrived at, of the physical -and chemical unity of the entire cosmos is certainly one of the most -valuable general truths which we owe to astrophysics, the new branch -of astronomy which is honorably associated with the name of Friedrich -Zöllner. Not less important is the clear knowledge we have obtained -that the same laws of mechanical development that we have on the -earth rule throughout the infinite universe. A vast, all-embracing -metamorphosis goes on continuously in all parts of the universe, -just as it is found in the geological history of the earth; it can -be traced in the evolution of its living inhabitants as surely as in -the history of peoples or in the life of each human individual. In -one part of space we perceive, with the aid of our best telescopes, -vast nebulæ of glowing, infinitely attenuated gas; we see in them the -embryos of heavenly bodies, billions of miles away, in the first stage -of their development. In some of these "stellar embryos" the chemical -elements do not seem to be differentiated yet, but still buried in the -homogeneous primitive matter (_prothyl_) at an enormous temperature -(calculated to run into millions of degrees); it is possible that the -original basic "substance" (_vide_ p. 229) is not yet divided into -ponderable and imponderable matter. In other parts of space we find -stars that have cooled down into glowing fluid, and yet others that -are cold and rigid; we can tell their stage of evolution approximately -by their color. We find stars that are surrounded with rings and moons -like Saturn; and we recognize in the luminous ring of the nebula the -embryo of a new moon, which has detached itself from the mother-planet, -just as the planet was released from the sun. - -Many of the stars, the light of which has taken thousands of years to -reach us, are certainly suns like our own mother-sun, and are girt -about with planets and moons, just as in our own solar system. We -are justified in supposing that thousands of these planets are in a -similar stage of development to that of our earth--that is, they have -arrived at a period when the temperature at the surface lies between -the freezing and boiling point of water, and so permits the existence -of water in its liquid condition. That makes it possible that carbon -has entered into the same complex combinations on those planets as -it has done on our earth, and that from its nitrogenous compounds -protoplasm has been evolved--that wonderful substance which alone, -as far as our knowledge goes, is the possessor of organic life. The -monera (for instance, chromacea and bacteria), which consist only of -this primitive protoplasm, and which arise by spontaneous generation -from these inorganic nitrocarbonates, may thus have entered upon the -same course of evolution on many other planets as on our own; first of -all, living cells of the simplest character would be formed from their -homogeneous protoplasmic body by the separation of an inner nucleus -from the outer cell body (cytostoma). Further, the analogy that we -find in the life of all cells--whether plasmodomous plant-cells or -plasmophagous animal-cells--justifies the inference that the further -course of organic evolution on these other planets has been analogous -to that of our own earth--always, of course, given the same limits of -temperature which permit water in a liquid form. In the glowing liquid -bodies of the stars, where water can only exist in the form of steam, -and on the cold extinct suns, where it can only be in the shape of ice, -such organic life as we know is impossible. - -The similarity of phylogeny, or the analogy of organic evolution, -which we may thus assume in many stars which are at the same stage of -biogenetic development, naturally opens out a wide field of brilliant -speculation to the constructive imagination. A favorite subject for -such speculation has long been the question whether there are men, or -living beings like ourselves, perhaps much more highly developed, in -other planets? Among the many works which have sought to answer the -question, those of Camille Flammarion, the Parisian astronomer, have -recently been extremely popular; they are equally distinguished by -exuberant imagination and brilliant style, and by a deplorable lack -of critical judgment and biological knowledge. We may condense in the -following thesis the present condition of our knowledge on the subject: - -I. It is very probable that a similar biogenetic process to that of our -own earth is taking place on some of the other planets of our solar -system (Mars and Venus), and on many planets of other solar systems; -first simple monera are formed by spontaneous generation, and from -these arise unicellular protists (first plasmodomous primitive plants, -and then plasmophagous primitive animals). - -II. It is very probable that from these unicellular protists arise, -in the further course of evolution, first social cell-communities -(coenobia), and subsequently tissue-forming plants and animals -(metaphyta and metazoa). - -III. It is also very probable that thallophyta (algæ and fungi) were -the first to appear in the plant-kingdom, then diaphyta (mosses and -ferns), finally anthophyta (gymnosperm and angiosperm flowering plants). - -IV. It is equally probable that the biogenetic process took a similar -course in the animal kingdom--that from the blastæads (catallacta) -first gastræads were formed, and from these lower animal forms -(coelenteria) higher organisms (coelomaria) were afterwards evolved. - -V. On the other hand, it is very questionable whether the different -stems of these higher animals (and those of the higher plants as well) -run through the same course of development on other planets as on our -earth. - -VI. In particular, it is wholly uncertain whether there are vertebrates -on other planets, and whether, in the course of their phyletic -development, taking millions of years, mammals are formed as on earth, -reaching their highest point in the formation of man; in such an event, -millions of changes would have to be just the same in both cases. - -VII. It is much more probable, on the contrary, that other planets -have produced other types of the higher plants and animals, which are -unknown on our earth; perhaps from some higher animal stem, which is -superior to the vertebrate in formation, higher beings have arisen who -far transcend us earthly men in intelligence. - -VIII. The possibility of our ever entering into direct communication -with such inhabitants of other planets seems to be excluded by the -immense distance of our earth from the other heavenly bodies, and the -absence of the requisite atmosphere in the intervening space, which -contains only ether. - -But while many of the stars are probably in a similar stage of -biogenetic development to that of our earth (for the last one hundred -million years at least), others have advanced far beyond this stage, -and, in their planetary old age, are hastening towards their end--the -same end that inevitably awaits our own globe. The radiation of heat -into space gradually lowers the temperature until all the water is -turned into ice; that is the end of all organic life. The substance -of the rotating mass contracts more and more; the rapidity of its -motion gradually falls off. The orbits of the planets and of their -moons grow narrower. At length the moons fall upon the planets, and -the planets are drawn into the sun that gave them birth. The collision -again produces an enormous quantity of heat. The pulverized mass of the -colliding bodies is distributed freely through infinite space, and the -eternal drama of sun-birth begins afresh. - -The sublime picture which modern astrophysics thus unveils before the -mind's eye shows us an eternal birth and death of countless heavenly -bodies, a periodic change from one to the other of the different -cosmogenetic conditions, which we observe side by side in the universe. -While the embryo of a new world is being formed from a nebula in -one corner of the vast stage of the universe, another has already -condensed into a rotating sphere of liquid fire in some far distant -spot; a third has already cast off rings at its equator, which round -themselves into planets; a fourth has become a vast sun whose planets -have formed a secondary retinue of moons, and so on. And between them -are floating about in space myriads of smaller bodies, meteorites, -or shooting-stars, which cross and recross the paths of the planets -apparently like lawless vagabonds, and of which a great number fall -onto the planets every day. Thus there is a continuous but slow change -in the velocities and the orbits of the revolving spheres. The frozen -moons fall onto the planets, the planets onto their suns. Two distant -suns, perhaps already stark and cold, rush together with inconceivable -force and melt away into nebulous clouds. And such prodigious heat -is generated by the collision that the nebula is once more raised to -incandescence, and the old drama begins again. Yet in this "perpetual -motion" the infinite substance of the universe, the sum total of its -matter and energy, remains eternally unchanged, and we have an eternal -repetition in infinite time of the periodic dance of the worlds, the -metamorphosis of the cosmos that ever returns to its starting-point. -Over all rules the law of substance. - - -II.--PROGRESS OF GEOLOGY - -The earth and its origin were much later than the heavens in becoming -the object of scientific investigation. The numerous ancient and modern -cosmogonies do, indeed, profess to give us as good an insight into the -origin of the earth as into that of the heavens; but the mythological -raiment, in which all alike are clothed, betrays their origin in -poetic fancy. Among the countless legends of creation which we find in -the history of religions and of thought there is one that soon took -precedence of all the rest--the Mosaic story of creation as told in -the first book of the Hexateuch. It did not exist in its present form -until long after the death of Moses (probably not until eight hundred -years afterwards); but its sources are much older, and are to be found -for the most part in Assyrian, Babylonian, and Hindoo legends. This -Hebrew legend of creation obtained its great influence through its -adoption into the Christian faith and its consecration as the "Word of -God." Greek philosophers had already, five hundred years before Christ, -explained the natural origin of the earth in the same way as that of -other cosmic bodies. Xenophanes of Colophon had even recognized the -true character of the fossils which were afterwards to prove of such -moment; the great painter, Leonardo da Vinci, of the fifteenth century, -also explained the fossils as the petrified remains of animals which -had lived in earlier periods of the earth's history. But the authority -of the Bible, especially the myth of the deluge, prevented any further -progress in this direction, and insured the triumph of the Mosaic -legend until about the middle of the last century. It survives even at -the present day among orthodox theologians. However, in the second half -of the eighteenth century, scientific inquiry into the structure of the -crust of the earth set to work independently of the Mosaic story, and -it soon led to certain conclusions as to the origin of the earth. The -founder of geology, Werner of Freiberg, thought that all the rocks were -formed in water, while Voigt and Hutton (1788) rightly contended that -only the stratified, fossil-bearing rocks had had an aquatic origin, -and that the Vulcanic or Plutonic mountain ranges had been formed by -the cooling down of molten matter. - -The heated conflict of these "Neptunian" and "Plutonic" schools was -still going on during the first three decades of the present century; -it was only settled when Karl Hoff (1822) established the principle of -"actualism," and Sir Charles Lyell applied it with signal success to -the entire natural evolution of the earth. The _Principles of Geology_ -of Lyell (1830) secured the full recognition of the supremely important -theory of continuity in the formation of the earth's crust, as opposed -to the catastrophic theory of Cuvier.[34] Palæontology, which had -been founded by Cuvier's work on fossil bones (1812), was of the -greatest service to geology; by the middle of the present century it -had advanced so far that the chief periods in the history of the earth -and its inhabitants could be established. The comparatively thin crust -of the earth was now recognized with certainty to be the hard surface -formed by the cooling of an incandescent fluid planet, which still -continues its slow, unbroken course of refrigeration and condensation. -The crumpling of the stiffened crust, "the reaction of the molten fiery -contents on the cool surface," and especially the unceasing geological -action of water, are the natural causes which are daily at work in the -secular formation of the crust of the earth and its mountains. - -To the brilliant progress of modern geology we owe three extremely -important results of general import. In the first place, it has -excluded from the story of the earth all questions of miracle, all -questions of supernatural agencies, in the building of the mountains -and the shaping of the continents. In the second place, our idea of -the length of the vast period of time which had been absorbed in their -formation has been considerably enlarged. We now know that the huge -mountains of the palæozoic, mesozoic, and cenozoic formations have -taken, not thousands, but millions of years in their growth. In the -third place, we now know that all the countless fossils that are found -in those formations are not "sports of nature," as was believed one -hundred and fifty years ago, but the petrified remains of organisms -that lived in earlier periods of the earth's history, and arose by -gradual transformation from a long series of ancestors. - - -III.--PROGRESS OF PHYSICS AND CHEMISTRY - -The many important discoveries which these fundamental sciences have -made during the nineteenth century are so well known, and their -practical application in every branch of modern life is so obvious, -that we need not discuss them in detail here. In particular, the -application of steam and electricity has given to our nineteenth -century its characteristic "machinist-stamp." But the colossal -progress of inorganic and organic chemistry is not less important. All -branches of modern civilization--medicine and technology, industry -and agriculture, mining and forestry, land and water transport--have -been so much improved in the course of the century, especially in the -second half, that our ancestors of the eighteenth century would find -themselves in a new world, could they return. But more valuable and -important still is the great theoretical expansion of our knowledge -of nature, which we owe to the establishment of the law of substance. -Once Lavoisier (1789) had established the law of the persistence of -matter, and Dalton (1808) had founded his new atomic theory with its -assistance, a way was open to modern chemistry along which it has -advanced with a rapidity and success beyond all anticipation. The same -must be said of physics in respect of the law of the conservation of -energy. Its discovery by Robert Mayer (1842) and Hermann Helmholtz -(1847) inaugurated for this science also a new epoch of the most -fruitful development; for it put physics in a position to grasp the -universal unity of the forces of nature and the eternal play of natural -processes, in which one force may be converted into another at any -moment. - - -IV.--PROGRESS OF BIOLOGY - -The great discoveries which astronomy and geology have made during the -nineteenth century, and which are of extreme importance to our whole -system, are, nevertheless, far surpassed by those of biology. Indeed, -we may say that the greater part of the many branches which this -comprehensive science of organic life has recently produced have seen -the light in the course of the present century. As we saw in the first -section, during the century all branches of anatomy and physiology, -botany and zoology, ontogeny and phylogeny, have been so marvellously -enriched by countless discoveries that the present condition of -biological science is immeasurably superior to its condition a hundred -years ago. That applies first of all _quantitatively_ to the colossal -growth of our positive information in all those provinces and their -several parts. But it applies with even greater force _qualitatively_ -to the deepening of our comprehension of biological phenomena, and -our knowledge of their efficient causes. In this Charles Darwin -(1859) takes the palm of victory; by his theory of selection he has -solved the great problem of "organic creation," of the natural -origin of the countless forms of life by gradual transformation. It -is true that Lamarck had recognized fifty years earlier that the -mode of this transformation lay in the reciprocal action of heredity -and adaptation. However, Lamarck was hampered by his lack of the -principle of selection, and of that deeper insight into the true -nature of organization which was only rendered possible after the -founding of the theory of evolution and the cellular theory. When we -collated the results of these and other disciplines, and found the -key to their harmonious interpretation in the ancestral development -of living beings, we succeeded in establishing the monistic biology, -the principles of which I have endeavored to lay down securely in my -_General Morphology_. - - -V.--PROGRESS OF ANTHROPOLOGY - -In a certain sense, the true science of man, rational anthropology, -takes precedence of every other science. The saying of the ancient -sage, "Man, know thyself," and that other famous maxim, "Man is the -measure of all things," have been accepted and applied from all time. -And yet this science--taking it in its widest sense--has languished -longer than all other sciences in the fetters of tradition and -superstition. We saw in the first section how slowly and how late -the science of the human organism was developed. One of its chief -branches--embryology--was not firmly established until 1828 (by Baer), -and another, of equal importance--the cellular theory--until 1838 (by -Schwann). And it was even later still when the answer was given to the -"question of all questions," the great riddle of the origin of man. -Although Lamarck had pointed out the only path to a correct solution -of it in 1809, and had affirmed the descent of man from the ape, it -fell to Darwin to establish the affirmation securely fifty years -afterwards, and to Huxley to collect the most important proofs of it -in 1863, in his _Place of Man in Nature_. I have myself made the first -attempt, in my _Anthropogeny_ (1874), to present in their historical -connection the entire series of ancestors through which our race has -been slowly evolved from the animal kingdom in the course of many -millions of years. - - - - -CONCLUSION - - -The number of world-riddles has been continually diminishing in the -course of the nineteenth century through the aforesaid progress of a -true knowledge of nature. Only one comprehensive riddle of the universe -now remains--the problem of substance. What is the real character of -this mighty world-wonder that the realistic scientist calls Nature or -the Universe, the idealist philosopher calls Substance or the Cosmos, -the pious believer calls Creator or God? Can we affirm to-day that the -marvellous progress of modern cosmology has solved this "problem of -substance," or at least that it has brought us nearer to the solution? - -The answer to this final question naturally varies considerably -according to the stand-point of the philosophic inquirer and his -empirical acquaintance with the real world. We grant at once that the -innermost character of nature is just as little understood by us as it -was by Anaximander and Empedocles twenty-four hundred years ago, by -Spinoza and Newton two hundred years ago, and by Kant and Goethe one -hundred years ago. We must even grant that this essence of substance -becomes more mysterious and enigmatic the deeper we penetrate into the -knowledge of its attributes, matter and energy, and the more thoroughly -we study its countless phenomenal forms and their evolution. We do not -know the "thing in itself" that lies behind these knowable phenomena. -But why trouble about this enigmatic "thing in itself" when we have -no means of investigating it, when we do not even clearly know whether -it exists or not? Let us, then, leave the fruitless brooding over this -ideal phantom to the "pure metaphysician," and let us instead, as "real -physicists," rejoice in the immense progress which has been actually -made by our monistic philosophy of nature. - -Towering above all the achievements and discoveries of the century -we have the great, comprehensive "law of substance," the fundamental -law of the constancy of matter and force. The fact that substance is -everywhere subject to eternal movement and transformation gives it the -character also of the universal law of evolution. As this supreme law -has been firmly established, and all others are subordinate to it, we -arrive at a conviction of the universal unity of nature and the eternal -validity of its laws. From the gloomy _problem_ of substance we have -evolved the clear _law_ of substance. The monism of the cosmos which we -establish thereon proclaims the absolute dominion of "the great eternal -iron laws" throughout the universe. It thus shatters, at the same time, -the three central dogmas of the dualistic philosophy--the personality -of God, the immortality of the soul, and the freedom of the will. - -Many of us certainly view with sharp regret, or even with a profound -sorrow, the death of the gods that were so much to our parents and -ancestors. We must console ourselves in the words of the poet: - - "The times are changed, old systems fall, - And new life o'er their ruins dawns." - -The older view of idealistic dualism is breaking up with all its mystic -and anthropistic dogmas; but upon the vast field of ruins rises, -majestic and brilliant, the new sun of our realistic monism, which -reveals to us the wonderful temple of nature in all its beauty. In the -sincere cult of "the true, the good, and the beautiful," which is the -heart of our new monistic religion, we find ample compensation for the -anthropistic ideals of "God, freedom, and immortality" which we have -lost. - -Throughout this discussion of the riddles of the universe I have -clearly defined my consistent monistic position and its opposition -to the still prevalent dualistic theory. In this I am supported by -the agreement of nearly all modern scientists who have the courage to -accept a rounded philosophical system. I must not, however, take leave -of my readers without pointing out in a conciliatory way that this -strenuous opposition may be toned down to a certain degree on clear -and logical reflection--may, indeed, even be converted into a friendly -harmony. In a thoroughly logical mind, applying the highest principles -with equal force in the entire field of the cosmos--in both organic and -inorganic nature--the antithetical positions of theism and pantheism, -vitalism and mechanism, approach until they touch each other. -Unfortunately, consecutive thought is a rare phenomenon in nature. The -great majority of philosophers are content to grasp with the right hand -the pure knowledge that is built on experience, but they will not part -with the mystic faith based on revelation, to which they cling with the -left. The best type of this contradictory dualism is the conflict of -pure and practical reason in the critical philosophy of the most famous -of modern thinkers, Immanuel Kant. - -On the other hand, the number is always small of the thinkers who -will boldly reject dualism and embrace pure monism. That is equally -true of consistent idealists and theists, and of logical realists and -pantheists. However, the reconciliation of these apparent antitheses, -and, consequently, the advance towards the solution of the fundamental -riddle of the universe, is brought nearer to us every year in the -ever-increasing growth of our knowledge of nature. We may, therefore, -express a hope that the approaching twentieth century will complete -the task of resolving the antitheses, and, by the construction of a -system of pure monism, spread far and wide the long-desired unity -of world-conception. Germany's greatest thinker and poet, whose one -hundred and fiftieth anniversary will soon be upon us--Wolfgang -Goethe--gave this "philosophy of unity" a perfect poetic expression, -at the very beginning of the century, in his immortal poems, _Faust_, -_Prometheus_, and _God and the World_: - - "By eternal laws - Of iron ruled, - Must all fulfil - The cycle of - Their destiny." - - - - -FOOTNOTES: - -[1] There are two English translations, _The Evolution of Man_ (1879) -and _The Pedigree of Man_ (1880). - -[2] The English translation, by Dr. Hans Gadow, bears the title of _The -Last Link_. - -[3] English translation, by J. Gilchrist, with the title of _Monism_. - -[4] E. Haeckel, _Systematische Phylogenie_, 1895, vol. iii., pp. -646-50. (Anthropolatry means "A divine worship of human nature.") - -[5] Cf. my Cambridge lecture, _The Last Link_, "Geological Time and -Evolution." - -[6] As to induction and deduction, _vide_ _The Natural History of -Creation_. - -[7] Rudolph Virchow, _Die Gründung der Berliner Universität und der -Uebergang aus dem Philosophischen in das naturwissenschaftliche -Zeitalter_. (Berlin; 1893.) - -[8] Cf. chap. iv. of my _General Morphology_, 1866; _Kritik der -naturwissenschaftlichen Methoden_. - -[9] _Systematische Phylogenie_, 1896, part iii., pp. 490, 494, and 496. - -[10] Translated in the International Science Series, 1872. - -[11] _Zell-Seelen und Seelen-Zellen._ Ernst Haeckel, _Gesammelte -populäre Vorträge. I. Heft._ 1878. - -[12] Cf. E. Haeckel, _The Systems of Darwin, Goethe, and Lamarck_. -Lecture given at Eisenach in 1882. - -[13] _Vide_ the translation of Dr. Hans Gadow: _The Last Link_. (A. & -C. Black.) - -[14] Cf. Max Verworn, _Psychophysiologische Protisten-Studien_, pp. -135, 140. - -[15] E. Haeckel, "General Natural History of the Radiolaria"; 1887. - -[16] _Vide Natural History of Creation_, E. Haeckel. - -[17] Law of individual variation. _Vide_ _Natural History of Creation_. - -[18] Cf. E. Haeckel, _Systematic Phylogeny_, vol. i. - -[19] Cf. _Anthropogeny_ and _Natural History of Creation_. - -[20] Cf. _Natural History of Creation_. - -[21] See chaps. xvi. and xvii. of my _Anthropogeny_. - -[22] E. Haeckel, _A Visit to Ceylon_. - -[23] Cf. _Monism_, by Ernst Haeckel. - -[24] Cf. _Monism_, by Ernst Haeckel. - -[25] Cf. _Monism_, by Ernst Haeckel. - -[26] Reinke, _Die Welt als That_ (1899). - -[27] Cf. _Monism_, by Ernst Haeckel. - -[28] _The Last Link_, translated by Dr. Gadow. - -[29] _General Morphology_, book 2, chap. v. - -[30] Cf. _General Morphology_, vol. ii., and _The Natural History of -Creation._ - -[31] _Vide_ _A Visit to Ceylon_, E. Haeckel, translated by C. Bell. - -[32] _Collected Popular Lectures_; Bonn, 1878. - -[33] As to the Greek paternity of Christ, _vide_ p. 328. - -[34] Cf. _The Natural History of Creation_, chaps. iii., vi., xv., and -xvi. - - - - -INDEX - - - Abiogenesis, 257, 369. - - Abortive organs, 264. - - Accidents, 216. - - Acrania, 166. - - Action at a distance, 217. - - Actualism, 249. - - Æsthesis, 225. - - Affinity, 224. - - Altruism, 350. - - Amphibia, 167. - - Amphimixis, 141. - - Ampitheism, 278. - - Ananke, 272. - - Anatomy, 22, etc. - comparative, 24. - - Anaximander, 289, 379. - - Anthropism, 11. - - Anthropistic illusion, 14, etc. - world-theory, 13. - - Anthropocentric dogma, 11, etc. - - Anthropogeny, 83. - - Anthropolatric dogma, 12. - - Anthropomorpha, 36. - - Anthropomorphic dogma, 12. - - Apes, 36, 37, 167. - anthropoid, 37. - - Archæus, 43. - - Archigony, 257. - - Aristotle, 23, 268. - - Association, centres of, 183. - of ideas, 121. - of presentations, 121, 122. - - Astronomy, progress of, 366. - - Astro-physics, 368. - - Atavism, 142. - - Athanatism, 189. - - Athanatistic illusions, 205. - - Atheism, 290. - - Atheistic science, 260. - - Atom, the, 222. - - Atomism, 223. - - Atomistic consciousness, 187. - - Attributes of ether, 227. - of substance, 216. - - Augustine of Hippo, 130. - - Auricular confession, 319, 359. - - Autogony, 257. - - - Baer (Carl Ernst), 57. - - Bastian (Adolf), 103. - - Beginning of the world, 240, 247. - - Bible, the, 282, 362. - - Biogenesis, 257. - - Biogenetic law, 81, 143. - - Bismarck, 334. - - Blastoderm, 150, 155. - - Blastosphere, 153. - - Blastula, 153. - - Bruno (Giordano), 290, 317. - - Büchner (Ludwig), 93. - - Buddhism, 326, 355. - - - Calvin, 130. - - Canonical gospels, 312. - - Carbon as creator, 256. - theory, 257. - - Catarrhinæ, 35. - - Catastrophic theory, 74. - - Categorical imperative, 350. - - Causes, efficient, 258. - final, 258. - - Celibacy, 358. - - Cell-love, 137. - community, soul of the, 155. - soul, 151. - state, 157. - - Cellular pathology, 50. - physiology, 48. - psychology, 153, 177. - theory, 26. - - Cenobitic soul, 155. - - Cenogenesis, 82. - of the psyche, 144. - - Chance, 274. - - Chemicotropism, 64, 136. - - Chordula, 64. - - Chorion, 68. - - Christ, father of, 327. - - Christian art, 339. - civilization, 356. - contempt of the body, 354. - animals, 355. - nature, 355. - self, 353. - the family, 357. - woman, 358. - ethics, 352. - - Christianity, 347. - - Church and school, 362. - state, 361. - - Cnidaria, 161. - - Conception, 64. - - Concubinage of the clergy, 358. - - Confession of faith, 302. - - Consciousness, 170. - animal, 176. - atomistic, 178. - biological, 176. - cellular, 177. - development of, 185. - dualistic, 182. - human, 173. - monistic, 182. - neurological, 174. - ontogeny of, 186. - pathology of, 182. - physiological, 180. - transcendental, 180. - - Constancy of energy, 212, 231. - matter, 212. - - Constantine the Great, 316. - - Constellations of substance, 218. - - Conventional lies, 323. - - Copernicus, 24, 320, 367. - - Cosmic immortality, 191. - - Cosmogonies, 234. - - Cosmological dualism, 257. - creationism, 235. - law, 211. - perspective, 14. - - Cosmos, the, 229. - - Creation, 73, 79, 234. - cosmological, 235. - dualistic, 236. - heptameral, 237. - individual, 237. - myths of, 236. - periodic, 237. - trialistic, 237. - - Cultur-kampf, 334. - - Cuvier, 74. - - Cyclostomata, 167. - - Cynopitheci, 46. - - Cytology, 26, etc. - - Cytopsyche, 151. - - Cytula, 64. - - - Darwin (Charles), 78, etc. - - Decidua, 69. - - Deduction, 16. - - Demonism, 276. - - Descartes, 99, 355. - - Descent of the ape, 85, etc. - of man, 87. - theory of, 77. - - Design, 264, 266. - in nature, 260. - in organisms, 266. - in selection, 261. - - Destruction of heavenly bodies, 243. - - Determinists, 130. - - Diaphragm, 31. - - Division of labor in matter, 229. - - Draper, 309, 333. - - Dualism, 20, etc. - - Du Bois-Reymond, 15 180, 235. - - Du Prel (Carl), 305. - - Duty, feeling of, 350. - - Dynamodes, 216. - - Dysteleology, 260. - - Echinodermata, 62. - - Ectoderm, 160. - sense-cells in the, 293. - - Egoism, 350. - - Elements, chemical, 222. - system of the, 222. - - Embryo, human, 64. - - Embryology, 54. - - Embryonic psychogeny, 144. - sleep, 146. - - Empedocles, 23, 224. - - Encyclica (of Pius IX.), 323. - - End of the world, 247. - - Energy, kinetic, 231. - potential, 231. - principle of, 230. - specific, 294. - - Entelecheia, 268. - - Entoderm, 160. - - Entropy of the universe, 247. - - Epigenesis, 56, 133. - - Ergonomy of matter, 229. - - Eternity of the world, 242. - - Ether, 225. - - Etheric souls, 199. - - Ethics, fundamental law of, 350. - - Evolution, theory of, 54, 239, 243. - chief element in, 267. - - Experience, 16. - - Extra-mundane God, 288. - - - Faith, confession of, 303. - of our fathers, 304. - - Family, the, and Christianity, 357. - - Fate, 272. - - Fechner, 97, etc. - - Fecundation, 63. - - Fetishism, 276. - - Feuerbach (Ludwig), 295. - - Flechsig, 183. - - Foetal membranes, 66. - - Folk-psychology, 103. - - Forces, conversion of, 231. - - Frederick the Great, 194, 315. - - - Galen, 23, 40. - - Gaseous souls, 199. - vertebrates, 288. - - Gastræa, 160. - theory of the, 60. - - Gastræads, 159. - - Gastrula, 61. - - Gegenbaur, 25, 30. - - Generation, theory of, 55. - - Genus, 73. - - Geology, periods of, 270. - progress of, 373. - - Germinal disk, 57. - - Gills, 65. - - God, 275. - the father, 277. - the son, 277, 328. - - Goethe, 20, etc. - - Goethe's monism, 331. - - Golden Rule, the, 351. - - Gospels, 312. - - Gravitation, theory of, 217. - - Gut-layer, 159. - - - Haller, 42. - - Harvey, 42. - - Helmholtz (Hermann), 213, 230. - - Heredity, psychic, 138. - - Hertz (Heinrich), 225. - - Hippocrates, 23. - - Histology, 26. - - Histopsyche, 156. - - Hoff (Carl), 250. - - Holbach (Paul), 193. - - Holy Ghost, 277, 326. - - Humboldt (Alexander), 343. - - Hydra, 161. - - Hylozoism, 289. - - Hypothesis, 299. - - - Iatrochemicists, 45. - - Iatromechanicists, 45. - - Ideal of beauty, 338. - of truth, 337. - of virtue, 339. - - Ignorabimus, 180. - - Immaculate conception, 326. - - Immaterial substance, 221. - - Immortality of animals, 201. - of the human soul, 188. - of unicellular organisms, 190. - personal, 192. - - Imperfection of nature, 264. - - Imponderable matter, 225. - - Impregnation, 64. - - Indeterminists, 130. - - Induction, 16. - - Indulgences, 359. - - Infallibility of the pope, 324. - - Instinct, 105, 123. - - Intellect, 125, etc. - - Intramundane God, 288. - - Introspective psychology, 95. - - Islam, 284. - - - Janssen (Johannes), 316. - - Jehovah, 283. - - Journeys on foot, 364. - - - Kant, 258, etc. - - Kant's metamorphosis, 92, etc. - - Kinetic energy, 231. - theory of substance, 216. - - Kölliker, 26, 48. - - - Lamarck, 76, etc. - - Lamettrie, 194. - - Landscape-painting, 343. - - Language, 126. - study of, 363. - - Last judgment, 209. - - Lavoisier, 212. - - Leap of the gospels, miraculous, 312. - - Leydig, 27. - - Life, definition of, 39. - - Limits of our knowledge, 182. - - Love, 357. - of animals, 355. - of neighbor, 350. - of self, 350. - - Lucretius Carus, 290. - - Lunarism, 281. - - Luther, 320. - - Lyell, 77, 250. - - - Madonna, cult of the, 284, 327. - - Malphigi, 54. - - Mammals, 30, etc. - - Mammary glands, 31. - - Man, ancestors of, 82. - - Marsupials, 32, 86. - - Mass, 222. - - Materialism, 20. - - Mayer (Robert), 213, 377. - - Mechanical causality, 366. - explanation, 259. - theory of heat, 247. - - Mechanicism, 259. - - Mediterranean religions, the, 282. - - Memory, cellular, 12O. - conscious, 121. - histionic, 121. - unconscious, 121. - - Mephistopheles, 279. - - Metabolism, 232. - - Metamorphoses of the cosmos, 372. - of philosophers, 92. - - Metaphyta, 156. - - Metasitism, 153. - - Metazoa, 60, 157. - - Middle Ages, 315, 358. - - Mixotheism, 286. - - Mohammedanism, 284. - - Mohr (Friedrich), 213. - - Monera, 257, 369. - - Monism, 20, and _passim_. - of energy, 254. - of Spinoza, 331. - of the cosmos, 255. - - Monistic anthropogeny, 252. - art, 341. - biogeny, 251. - churches, 345. - cosmology, 368. - ethics, 347. - geogeny, 248. - - Monotheism, 279. - - Monotrema, 32. - - Moon-worship, 281. - - Moral order of the universe, 269. - - Morula, 155. - - Mosaism, 283. - - Müller (Johannes), 25, 45, 262. - - Mythology of the soul, 135. - - - Natural religion, 344. - - Navel-cord, 69. - - Neokantians, 349. - - Neovitalism, 264. - - Neptunian geology, 375. - - Neuro-muscular cells, 114. - - Neuroplasm, 91, 109. - - Neuropsyche, 162. - - Nomocracy, 9. - - - Ontogenetic psychology, 103. - - Ontological creationism, 235. - methods, 249. - - Orbits of the heavenly bodies, 241. - - Origin of movement, 15, 241. - of feeling, 15, 241. - - Ovary, 63. - - - Palingenesis, 82. - of the psyche, 143. - - Pandera (the father of Christ), 328. - - Pantheism, 288. - - Papacy, 314. - - Papal ethics, 359. - - Papiomorpha, 37. - - Paul, 313, 357. - epistles of, 312. - - Paulinism, 313. - - Pedicle of the allantois, 69. - - Perpetual motion, 245. - - Persistence of force, 212, 231. - of matter, 212. - - Phroneta, 293. - - Phylogeny, 71, 81. - of the apes, 51. - systematic, 81. - - Physiology, 39. - - Phytopsyche, 157. - - Pithecanthropus, 87. - - Pithecoid theory, 82, etc. - - Pithecometra-thesis, 69, 85. - - Placenta, 32, 68. - - Placentals, 32, 86. - - Plasmodoma, 153. - - Plasmogony, 257. - - Plasmophaga, 154. - - Plato, 99, 197. - - Plato's theory of ideas, 269. - - Platodaria, 160. - - Platodes, 160. - - Platyrrhinæ, 35. - - Pneuma zoticon, 40. - - Polytheism, 276. - - Ponderable matter, 222. - - Preformation theory, 54. - - Primaria, 33. - - Primates, 33, 86. - - Primitive Christianity, 311. - gut, 61, 161. - - Prodynamis, 216. - - Progaster, 161. - - Proplacentals, 85. - - Prosimiæ, 34. - - Prostoma, 161. - - Prothyl, 223. - - Protoplasm, 90. - - Protozoa, 60. - - Provertebræ, 166. - - Pseudo-Christianity, 321. - - Psychade theory, 178. - - Psyche, 88. - - Psychogeny, 135. - phyletic, 149. - post-embryonic, 146. - - Psychology, 88 et seqq. - ontogenetic, 104. - phylogenetic, 104. - - Psychomonism, 226. - - Psychophysics, 97. - - Psychoplasm, 91, 110. - - Pupa, sleep of the, 146. - - Pyknosis, 218. - - Pyknotic theory of substance, 218. - - - Reason, 17, 125. - - Reflex action, 112. - arches, 114. - - Reformation, the, 319. - - Religion a private concern, 361. - - Remak, 58. - - Revelation, 306. - - Reversion, 142. - - Romance of the Virgin Mary, 327. - - Romanes, 106. - - Rudimentary organs, 264. - - - Saints, 284. - - Scale of emotion, 127. - of memory, 120. - of movement, 111. - of presentation, 118. - of reason, 122. - of reflex action, 113. - of will, 127. - - Scatulation theory, 55. - - Schleiden, 26, 47. - - School, and Church, 361. - and State, 362. - reform of the, 363. - - Schwann, 26, 47. - - Selachii, 166. - - Selection, theory of, 79. - - Self-consciousness, 171. - - Sense-knowledge, 297. - organs, 293. - - Senses, philosophy of the, 295. - - Sentiment, 17, etc., 331. - - Siebold, 27. - - Simiæ, 34. - - Social duties, 351. - instincts, 350. - - Solar systems, 241, 369. - - Solarism, 280. - - Soul, 88 _et seqq._ - apparatus of the, 162. - blending of the, 141. - creation of the, 135. - division of the, 135. - etheric, 199. - gaseous, 199. - histionic, 157. - history of the, 167. - hydra, 161. - life of the, 90. - liquid, 200. - mammal, 167. - nerve, 162. - origin of the, 135. - of the plant, 157. - personal, 162. - solid, 201. - substance of the, 198. - transmigration of the, 135. - - Sources of knowledge, 293. - - Space and time, 244. - infinity of, 242. - reality of, 244. - - Species, 73. - - Spectral analysis, 241. - - Spermarium, 63. - - Spermatozoa, 58. - - Spinal cord, 165. - - Spinoza, 21, 215, 290. - - Spirit world, 221. - - Spirit-rapping, 305. - - Spiritism, 304. - - Spiritualism, 20. - - Sponge, soul of the, 161. - - Stem-cell, 63, 138, 151. - - Stimulated movement, 113, 116. - - Stimuli, conduction of, 158. - - Strauss (David), 309, 313. - - Struggle for life, 270. - - Substance, 215. - law of, 211, etc. - structure of, 229. - - Superstition, 301. - - Süss (Edward), 250. - - Syllabus, 323. - - Synodikon (of Pappus), 312. - - - Table-turning, 305. - - Teleological explanation, 259. - - Teleology, 258. - - Tetrapoda, 29. - - Thanatism, 189. - primary, 192. - secondary, 192. - - Theism, 276. - - Theocracy, 9. - - Theory, 299. - - Thought, organs of, 126, 183, 293. - - Time and space, 244. - reality of, 246. - - Tissue, theory of, 26. - - Tissue-forming animals, 157. - plants, 156. - - Transformism, 76. - - Trimurti, 278. - - Trinity, dogma of the, 277. - monistic, 336. - - Triplotheism, 277. - - Tropesis, 225. - - Tropismata, 128. - - Tunicata, 165. - - Turbellaria, 161. - - - Ultramontanism, 310. - - Understanding, 125. - - Unity of natural forces, 231. - of substance, 214. - - Universum perpetuum mobile, 245. - - Uterus, 34. - - - Vaticanism, 314. - - Vertebrates, 27, _passim_. - - Verworn (Max), 48, 116. - - Vesalius, 24. - - Vibration, theory of, 216. - - Virchow, 26, 50. - - Virchow's metamorphosis, 93. - - Vital force, 42, 262. - - Vitalism, 43, 262. - - Vivisection, 41. - - Vogt (Carl), 93. - - Vogt (J.E.), 218. - - - Water-color drawing, 364. - - Weismann, 190. - - Will, liberty of the, 129. - scale of the, 128. - - Wolff (C.F.), 56. - - Woman and Christianity, 358. - - World-consciousness, 171. - - World-riddles, number of, 15. - - Wundt (Wilhelm), 100, 171. - - - THE END - - - - - Transcriber's notes: - - The following is a list of changes made to the original. - The first line is the original line, the second the corrected one. - - (12) Consequently, the so-called history of the world" - (12) Consequently, the so-called "history of the world" - - structure of the primates forces us to distingiush two - structure of the primates forces us to distinguish two - - of the geneaology of our race; for man bears all the - of the genealogy of our race; for man bears all the - - world of which we have direct and certain cognizanze - world of which we have direct and certain cognizance - - the law of substance by Robert Mayer and Helmholz - the law of substance by Robert Mayer and Helmholtz - - The more impotant of these works we owe to Romanes - The more important of these works we owe to Romanes - - Formerly assistant and pupil of Helmholz, Wundt had early - Formerly assistant and pupil of Helmholtz, Wundt had early - - all other viviporous animals, precisely because the complete - all other viviparous animals, precisely because the complete - - recent students of the protists, afford conlcusive evidence - recent students of the protists, afford conclusive evidence - - a thinker is very striking; in explaning it, it is not - a thinker is very striking; in explaining it, it is not - - "have no individuals and no generations in the matazoic sense." - "have no individuals and no generations in the metazoic sense." - - in his _Species and Studies_ in his eighty-fouth year - in his _Species and Studies_ in his eighty-fourth year - - Chief Forms of Theism--Polytheism--Tritheism--Ampitheism - Chief Forms of Theism--Polytheism--Triplotheism--Amphitheism - - faith, and that all these insiduous institutions are - faith, and that all these insidious institutions are - - nor in the narnow prisons of our jail-like schools, - nor in the narrow prisons of our jail-like schools, - - And it was done in many, and sometimes very romatic, ways. - And it was done in many, and sometimes very romantic, ways. - - - - - -End of the Project Gutenberg EBook of The Riddle of the Universe at the -close of the nineteenth century, by Ernst Haeckel - -*** END OF THIS PROJECT GUTENBERG EBOOK THE RIDDLE OF THE UNIVERSE *** - -***** This file should be named 42968-8.txt or 42968-8.zip ***** -This and all associated files of various formats will be found in: - http://www.gutenberg.org/4/2/9/6/42968/ - -Produced by Charlene Taylor, Paul Clark, Marilynda -Fraser-Cunliffe and the Online Distributed Proofreading -Team at http://www.pgdp.net - - -Updated editions will replace the previous one--the old editions -will be renamed. - -Creating the works from public domain print editions means that no -one owns a United States copyright in these works, so the Foundation -(and you!) can copy and distribute it in the United States without -permission and without paying copyright royalties. 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