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Robinson 3 44+A2 = SEF Man, the Unknown Man The Unknown BY ALEXIS CARREL CONTAINING A NEW INTRODUCTION New York and London HARPER € BROTHERS PUBLISHERS MAN, THE UNKNOWN Copyright, 1935, 1939, by Harper & Brothers Printed in the United States of America All rights in this book are reserved. No part of the book may be reproduced in any manner whatsoever without written permis- sion. For information address Harper & Brothers A-H To My Friends FREDERIC R. COUDERT CORNELIUS CLIFFORD and BORIS A. BAKHMETEFF this book is dedicated Contents II Wil VIII Introduċćtion Preface The Need of a Bétter Knowledge of Man The Science of Man Body and Physiological Activities Mental A tivities Inward Time Adaptive Functions The Individual The Remaking of Man 1X X1X 117 159 191 235 274. Introduction THIS BOOK is having the paradoxical destiny of becoming more timely while it grows older. Since its publication, its significance has increased continually. For the value of ideas, as of all things, is relative. It augments or decreases accord- ing to our state of mind. Under the pressure of the events that agitate Europe, Asia, and America, our mental attitude has progressively changed. We are beginning to understand the meaning of the crisis. We know that it does not consist simply in the cyclic recurrence of economic disorders. That neither prosperity nor war will solve the problems of modern sociéty. Like sheep at the approach of a storm, civilized hu- manity vaguely feels the presence of danger. And we are driven by anxiéty toward the ideas that deal with the mystery of our ills. This book originated from the observation of a simple fact—the high development of the sciences of inanimate matter, and our ignorance of life. Mechanics, chemistry, and physics have progressed much more rapidly than physi- ology, psychology, and sociology. Man has gained the mas- tery of the material world before knowing himself. Thus, modern sociéty has been built at random, according to the chance of scientific discoveries and to the fancy of ideolo- gies, without regard for the laws of our body and soul. We have been the victims of a disastrous illusion—the illusion of our ability to emancipate ourselves from natural laws. We have forgotten that nature never forgives. [ix] INTRODUCTION In order to endure, sociéty, as well as individuals, should conform to the laws of life. We cannot erect a house with- out a knowledge of the law of gravity. “In order to be commanded, nature must be obeyed,” said Bacon. The essential needs of the human being, the characteristics of his mind and organs, his relations with his environment are easily subjected to scientific observation. The juris diction of science extends to all observable phenomena— the spiritual as well as the intellectual and the physio logical. Man in his entiréty can be apprehended by the scientific method. But the science of man differs from all other sciences. It must be synthetic as well as analytic, since man is simultaneously unity and multiplicity. This science alone is capable of giving birth to a technique for the con- struction of sociéty. In the future organization of the in- dividual and collective life of humanity, philosophical and social doctrines must give precedence to the positive knowl- edge of ourselves. Science, for the first time in the history of the world, brings to a tottering civilization the power to renovate itself and to continue its ascension. The necessity for this renovation is becoming more evi- dent each year. Newspapers, magazines, cinema, and radio ceaselessly spread news illustrating the growing contrast bétween material progress and social disorder. The tri- umphs of science in some fields mask its impotence in others. For the marvels of technology, such as featured, for example, in the New York World’s Fair, create comfort, simplify our existence, increase the rapidity of communi- cations, put at our disposal quantities of new materials, synthesize chemical products that cure dangerous diseases [x] INTRODUCTION as if by magic. But they fail to bring us economic security, happiness, moral sense, and peace. These royal gifts of science have burst like a thunderstorm upon us while we are Still too ignorant to use them wisely. And they may become highly destructive. Will they not make war an unprecedented catastrophe? For they will be responsible for the death of millions of men who are the flower of civilization, for the destruction of priceless treasures ac- cumulated by centuries of culture on the soil of Europe, and for the ultimate weakening of the white race. Modern life has brought another danger, more subtle but still more formidable than war: the extinction of the best elements of the race. The birth rate is falling in all nations, except in Germany and Russia. France is becoming depopulated already. England and Scandinavia will soon be in the same condition. In the United States, the upper third of the population reproduces much less rapidly than the lower third. Europe and the United States are thus undergoing a qualitative as well as quantitative déterioration. On the contrary, the Asiatics and Africans, such as the Russians, the Arabs, the Hindus, are increasing with marked rapidity. Never have the European races been in such great peril as today. Even if a suicidal war is avoided, we will be faced with degeneration because of the sterility of the strongest and most intelligent stock. No conquests deserve so much admiration as those made by physiology and medicine. The civilized nations are now protected from the great epidemics, such as plague, cholera, typhus, and other infectious diseases. Owing to hygiene and to a growing knowledge of nutrition, the inhabitants of the overpopulated cities are clean, well-nourished, in bétter [xi] INTRODUCTION health, and the average duration of life has increased con- siderably. Nevertheless, hygiene and medicine, even with the aid of the schools, have not succeeded in improving the intellectual and moral quality of the population. Modern men and women manifest nervous weakness, mental in- Stability, lack of moral sense. About 15 per cent remain at the psychologic age of twelve years. There are hosts of feeble-minded and insane. ‘The number of misfits reaches perhaps thirty or forty million. Furthermore, criminality increases. ‘The recent statistics of J. Edgar Hoover show that this country actually contains nearly five million crim- inals. The tone of our civilization cannot help being in- fluenced by the prevalence of mental weakness, dishonesty, and criminality. It is significant that panic spread through the population when a radio cast enacted an invasion of the earth by the inhabitants of Mars. Also, that a former president of the Stock Exchange of New York was con- victed of theft, and an eminent Federal judge of selling his verdicts. At the same time, normal individuals are being crushed under the weight of those who are incapable of adapting themselves to life. The majority of the people lives on the work of the minority. Despite the enormous sums spent by the government, the economic crisis con- tinues. In the richest country of the world, millions are in want. It is evident that human intelligence has not in- creased simultaneously with the complexity of the prob- lems to be solved. ‘Today, as much as in the past, civilized humanity shows itself incapable of directing either its in- dividual or its collective existence. As a matter of fact, modern sociéty—that society pro- [xii] INTRODUCTION duced by science and technology—is committing the same mistake as have all the civilizations of antiquity. It has created conditions of life wherein life itself becomes im- possible. It justifies the sally of Dean Inge: “Civilization is a disease which is almost invariably fatal.” The real sig- nificance of the events that are taking place in Europe and in this country is not yet understood by the public. Never- theless, it is becoming obvious to those few who have the inclination and the time to think. Our civilization is in danger. And this danger menaces simultaneously the race, the nations, and the individuals. Each one of us will be Struck by the ruin brought about by a European war. Each one suffers already from the confusion in our life and in our social institutions, from the general weakening of moral sense, from economic insecurity, from the burden imposed upon the community by defectives and criminals. ‘The crisis is due neither to the presence of Mr. Roosevelt in the White House, nor to that of Hitler in Germany nor of Mussolini in Rome. It comes from the very Structure of civilization. It is a crisis of man. Man is not able to manage the world derived from the caprice of his intelligence. He has no other alternative than to remake this world accord- ing to the laws of life. He must adapt his environment to the nature of his organic and mental activities, and reno- vate his habits of existence. Otherwise, modern sociéty will join ancient Greece and the Roman Empire in the realm of nothingness. And the basis of this renovation can be found only in the knowledge of our body and soul. No lasting civilization will ever be founded upon philo- sophical and social ideologies. The democratic ideology it- [xiii | INTRODUCTION self, unless reconstructed upon a scientific basis, has no more chance of surviving than the fascist or marxist ideol- ogies. For none of these syStems embraces man in his entire reality. In truth, all political and economic doctrines have so far ignored the science of man. However, the power of the scientific méthod is obvious. Science has conquered the material world. And science will give man, if his will is indomitable, mastery over life and over himself. The domain of science comprises the totality of the observable and of the measurable. That is, all the things that are located in the spatio-temporal continuum—man, as well as the ocean, the clouds, the atoms, the stars. As man is endowed with mental activities, science reaches through him the world of the mind, that world which Sstrétches beyond space and time. Observation and experience are the only means of apprehending reality in a positive manner. For observation and experience give birth to concepts which, although incomplete, remain éternally true. These concepts are operational concepts, as defined by Bridgman. They proceed directly from the measurement or the accu- rate observation of things. They are applicable to the Study of man as well as to that of inanimate objects. For such a study, they must be constructed in as great a num- ber as possible, with the aid of all the techniques that we are capable of developing. In the light of these con- cepts, man appears as unity and multiplicity—a center of activities simultaneously material and spiritual, and Strictly dependent on the physicochemical and psychological en- vironment in which he is immersed. Considered thus in a concréte manner, he differs profoundly from the abstract being dreamed by political and social ideologies. It is upon [ xiv ] INTRODUCTION this concrete man, and not upon abstractions, that sociéty should be erected. There is no other road open to human progress than the optimum development of all the physio- logical, intellectual, and spiritual potentialities of the in- dividual. Only apprehension of the whole reality can save modern man. We must, therefore, give up philosophical systems, and rely exclusively upon scientific concepts. The natural fate of all civilizations is to rise and to de- cline—and to vanish into dust. Our civilization may per- haps escape the common fate, because it has at its disposal the unlimited resources of science. But science deals ex- clusively with the forces of intelligence. And intelligence never urges men to action. Only fear, enthusiasm, self- sacrifice, hatred, and love can infuse with life the products of our mind. The youth of Germany and Italy, for example, are driven by faith to sacrifice themselves for an ideal— even if that ideal is false. Perhaps the democracies will also engender men burning with the passion to create. Perhaps, in Europe and in America, there are such men, still young, poor, and unknown. But enthusiasm and faith, if not united to the knowledge of the whole reality, will remain Sterile. The Russian revolutionists had the will and the strength to build up a new civilization. They failed because they relied upon the incompléte vision of Karl Marx, instead of a truly scientific concept of man. ‘The renovation of mod- ern sociéty demands, besides a profound spiritual urge, the knowledge of man in his wholeness. But the wholeness of man has many different aspects. These aspects are the object of special sciences, such as physiology, psychology, sociology, eugenics, pedagogy, medi- [xv] INTRODUCTION cine, and many others. There are specialists for each of them. But none for man as a whole. Special sciences are incapable of solving even the most simple human problems. An architect, a schoolmaster, a physician, for example, are acquainted in an incompléte manner with the problems of habitation, education, and health. For each of these problems concerns all human activities, and transcends the frontiers of any special science. There is, at this moment, imperative need for men possessing, like Aristotle, univer- sal knowledge. But Aristotle himself could not embrace all modern sciences. We must, therefore, have recourse to com- posite Aristotles. That is, to small groups of men belonging to different specialties, and capable of welding their in- dividual thoughts into a synthétic whole. Such minds can certainly be found—minds endowed with that universalism which spreads its tentacles over all things. The technique of collective thinking requires much intelligence and dis- interestedness. Few individuals are apt at this type of re- search. But collective thinking alone will permit human problems to be solved. Today, mankind should be given an immortal brain, a permanent focus of thoughts to guide its faltering steps. Our institutions for scientific research are not sufficient, because their discoveries are always frag- mentary. In order to build a science of man, and a tech- nology of civilization, centers of synthesis must be created where collective thinking and integration of specialized data will forge a new knowledge. In this manner, both in- dividuals and sociéty will be given the immovable founda- tions of operational concepts, and the power to survive. To sum up, the events of the last few years have ren- [xvi] INTRODUCTION dered more evident the danger menacing the entire civili- zation of the Occident. However, the public does not yét fully understand the significance of the economic crisis, of the decline in the birth rate, of the moral, nervous, and mental decay of the individual. It does not conceive how immense a catastrophe a European war will be for human- ity—how urgent is our renovation. Nevertheless, in demo- cratic countries, the initiative for this renovation must emanate from the people, and not from the leaders. ‘This is the reason for presenting this book again to the public. Although, during the four years of its career, it has spread beyond the frontiers of the English-speaking countries through all civilized nations, the ideas that it contains have reached only a few million persons. To contribute, even in a humble manner, to the construction of the new City, these ideas must invade the population as the sea infiltrates the sands of the shore. Our renovation can come only from the effort of all. “To progress again, man must remake him- self. And he cannot remake himself without suffering. For he is both the marble and the sculptor. In order to uncover his true visage, he must shatter his own substance with heavy blows of his hammer.” New York, June 15, 1939 [xvii] Preface THE AUTHOR of this book is not a philosopher. He is only a man of science. He spends a large part of his time in a laboratory studying living matter. And another part in the world, watching human beings and trying to understand them. He does not prétend to deal with things that lie out- side the field of scientific observation. In this book he has endeavored to describe the known, and to separate it clearly from the plausible. Also to recog- nize the existence of the unknown and the unknowable. He has considered man as the sum of the observations and experiences of all times and of all countries. But what he describes he has either seen with his own eyes or learned directly from those with whom he associates. It is his good fortune to be in a position to study, without making any effort or deserving any credit, the phenomena of life in their bewildering complexity. He has observed practically every form of human activity. He is acquainted with the poor and the rich, the sound and the diseased, the learned and the ignorant, the weak-minded, the insane, the shrewd, the criminal, étc. He knows farmers, proletarians, clerks, shop- keepers, financiers, manufacturers, politicians, statesmen, soldiers, professors, school-teachers, clergymen, peasants, bourgeois, and aristocrats. The circumstances of his life have led him across the path of philosophers, artists, poéts, and scientists. And also of geniuses, heroes, and saints. At the same time, he has studied the hidden mechanisms which, in [xix ] PREFACE the depth of the tissues and in the immensity of the brain, are the substratum of organic and mental phenomena. He is indebted to the techniques of modern civilization for the possibility of witnessing such a gigantic spectacle. These techniques have enabled him simultaneously to give his attention to several subjects. He lives in the New World, and also in the Old. He has the privilege of spending most of his time in the Rockefeller Institute for Medical Re- search, as one of the scientists brought together in that In- stitute by Simon Flexner. ‘There he has contemplated the phenomena of life while they were analyzed by incom- parable experts such as Meltzer, Jacques Loeb, Noguchi, and many others. Owing to the genius of Flexner, the study of living things has been undertaken with a broadness of vision so far unequaled. Matter is investigated in those laboratories at every level of its organization, of its ascension toward the making of man. With the help of X-rays, physi- cists are unveiling the architectonic of the molecules of the simpler substances of our tissues—that is, the spatial rela- tions of the atoms constituting those molecules. Chemists and physical chemists devote themselves to the analysis of the more complex substances encountered within the body, such as the hemoglobin of the blood, the proteins of the tissues and the humors, and the ferments responsible for the un- ceasing splitting and building up of those enormous aggre- gates of atoms. Instead of directing their attention to the molecular edifices themselves, other chemists consider the relations of those edifices with one another when they en- ter the fluids of the body. In short, the physicochemical equilibria that maintain constant the composition of blood serum in spite of the perpétual changes of the tissues. Thus [xx ] PREFACE are brought to light the chemical aspects of physiological phenomena. Several groups of physiologists, with the aid of the most varied techniques, are studying the larger structures resulting from the aggregation and organization of mole- cules, the cells of the tissues and of the blood—that 1s, living matter itself. They examine those cells, their ways of associa- tion, and the laws governing their relations with their sur- roundings; the whole made up of the organs and humors; the influence of the cosmic environment on this whole; and the effects of chemical substances on tissues and conscious- ness. Other specialists devote themselves to the investigation of those small beings, the viruses and bacteria, whose pres- ence in our tissues is responsible for infectious diseases; of the marvelous méthods used by the organism in its fight against them; of the degenerative diseases, such as cancer, heart lesions, nephritis. Finally, the momentous problem of indi- viduality and of its chemical basis is being successfully at- tacked. The writer has had the exceptional opportunity of listening to great men specialized in these researches, and of following the results of their experiments. ‘Thus, the effort of inert matter toward organization, the properties of living beings, and the harmony of our body and our mind ap- peared to him in their beauty. In addition, he himself has Studied the most diverse subjects, from surgery to cell physi- ology and to métapsychics. ‘This was made possible by fa- cilities which, for the first time, were put at the disposal of science for the performance of its task. It seems that the subtle inspiration of Welch and the practical idealism of Frederick T. Gates caused new conceptions of biology and new formulas for research to spring from Flexner’s mind. To ihe pure spirit of science Flexner gave the help of new [xxi] PREFACE méthods designed to save the workers’ time, to facilitate their free coöperation, and to create bétter experimental tech- niques. Owing to these innovations, one cannot only under- take extensive researches of one’s own, but also acquire a first-hand knowledge of subjects whose mastery in former days necessitated the whole lifétime of several scientists. We now possess such a large amount of information on human beings that its very immensity prevents us from using it properly. In order to be of service, our knowledge must be synthétic and concise. This book, therefore, was not intended to be a treatise on Man. For such a treatise would run into dozens of volumes. The author’s intention was merely to build up an intelligible synthesis of the data which we pos- sess about ourselves. He has attempted to describe a large number of fundamental facts in a very simple manner, and still not to be elementary. Not to indulge in scientific popu- larization or to offer to the public a weak and childish aspect of reality. He has written for the scholar as well as for the layman. He fully understands the difficulties inherent in the temerity of his undertaking. He has tried to confine all knowledge of man within the pages of a small book. Of course, he has not succeeded. He will not satisfy the spe- cialists, because they know far more than he does, and they will regard him as superficial. Neither will he please the general public, for this volume contains too many technical détails. However, in order to acquire a synthétic knowledge of ourselves, it was indispensable to summarize the data of several sciences, and also to depict with bold and rapid Strokes the physical, chemical, and physiological mechanisms hidden under the harmony of our acts and our thoughts. Cxxii | PREFACE We must realize that an attempt, however awkward and though partly a failure, is bétter than no attempt at all. The necessity of compressing a large amount of informa- tion into a short space has important drawbacks. It gives a dogmatic appearance to propositions which are nothing but conclusions of observations and experiments. Subjects that have engrossed physiologists, hygienists, physicians, edu- cators, economists, sociologists for years have often had to be described in a few lines or a few words. Almost every sentence of this book is the expression of the long labor of a scientist, of his patient researches, sométimes of his entire lifétime spent in the study of a single problem. For the sake of conciseness, the writer has been obliged briefly to sum- marize gigantic masses of observations. Thus, descriptions of facts have been given the form of assertions. To a similar cause may be attributed a seeming lack of accuracy. Most organic and mental phenomena have been treated in a dia- grammatic manner. ‘Therefore, things that markedly differ appear to be grouped togéther. As, at a distance, houses, rocks, and trees are not distinguishable from one another. It must not be forgotten that in this book the expression of reality is only approximately accurate. A brief description of an immense subject involves inevitable defects. But the skétch of a landscape should not be expected to contain all the détails of a photograph. Before beginning this work the author fenied its diff- culty, its almost impossibility. He undertook it merely be- cause somebody had to undertake it. Because men cannot follow modern civilization along its present course, because they are degenerating. ‘hey have been fascinated by the beauty of the sciences of inert matter. They have not under- [ xxiii | PREFACE stood that their body and consciousness are subjected to natural laws, more obscure than, but as inexorable as, the laws of the sidereal world. Neither have they understood that they cannot transgress these laws without being pun- ished. They must, therefore, learn the necessary relations of the cosmic universe, of their fellow men, and of their inner selves, and also those of their tissues and their mind. Indeed, man stands above all things. Should he degenerate, the beauty of civilization, and even the grandeur of the physical universe, would vanish. For these reasons this book was written. It was not written in the peace of the country, but in the confusion, the noise, and the weariness of New York. The author has been urged to carry out this work by his friends, philosophers, scientists, jurists, economists, with whom he has for years discussed the great problems of our time. From Frederic R. Coudert, whose penetrating vision reaches, beyond the horizons of America, those of Europe, came the impulse responsible for this book. Indeed, the majority of the nations follow the lead of North America. ‘Those countries that have blindly adopted the spirit and the techniques of industrial civilization, Russia as well as England, France, and Germany, are exposed to the same dangers as the United States. Humanity’s atten- tion must turn from the machines and the world of inanimate matter to the body and the soul of man, to the organic and mental processes which have created the ma- chines and the universe of Newton and Einstein. The only claim of this book is to put at everyone’s dis- posal an ensemble of scientific data concerning the human beings of our time. We are beginning to realize the weak- ness of our civilization. Many want to shake off the dogmas [xxiv] PREFACE imposed upon them by modern sociéty. This book has been written for them, and also for those who are bold enough to understand the necessity, not only of mental, political, and social changes, but of the overthrow of industrial civilization and of the advent of another conception of human progress. This book is, therefore, dedicated to all whose everyday task is the rearing of children, the forma- tion or the guidance of the individual. To school-teachers, hygienists, physicians, clergymen, social workers, professors, judges, army officers, engineers, economists, politicians, in- dustrial leaders, étc. Also to those who are interested in the mere knowledge of our body and our mind. In short, to every man and every woman. It is offered to all as a simple account of facts revealed about human beings by scientific observation. Man, the Unknown Chapter I THE NEED OF A BETTER KNOWLEDGE OF MAN 1. The sciences of life have progressed more slowly than those of inert matter. Our ignorance of ourselves. 2. This ignorance is due to our ancestors’ mode of existence, to the complexity of man, and to the structure of our mind. 3. How mechanical, physical, and chemical sciences have modified our environment. 4. The results of such a change. 5. This change is harmful, having been made without due consideration of our nature. 6. Need of a more complete knowledge of ourselves. I THERE is a Strange disparity bétween the sciences of inert matter and those of life. Astronomy, mechanics, and physics are based on concepts which can be expressed, tersely and elegantly, in mathematical language. They have built up a universe as harmonious as the monuments of ancient Greece. They weave about it a magnificent texture of calculations and hypotheses. ‘They search for reality beyond the realm of common thought up to unutterable abstrac- tions consisting only of equations of symbols. Such is not the position of biological sciences. Those who investigate the phenomena of life are as if lost in an inextricable jungle, in the midst of a magic forest, whose countless trees unceasingly change their place and their shape. They are crushed under a mass of facts, which they can describe but are incapable of defining in algebraic equations. From the [1] MAN, THE UNKNOWN things encountered in the material world, whéther atoms or stars, rocks or clouds, steel or water, certain qualities, such as weight and spatial dimensions, have been abstracted. These abstractions, and not the concrete facts, are the mat- ter of scientific reasoning. The observation of objects con- stitutes only a lower form of science, the descriptive form. Descriptive science classifies phenomena. But the unchang- ing relations bétween variable quantities—that is, the natural laws, only appear when science becomes more abstract. It is because physics and chemistry are abstract and quantitative that they had such great and rapid success. Although they do not prétend to unveil the ultimate nature of things, they give us the power to predict future events, and often to détermine at will their occurrence. In learning the secret of the constitution and of the properties of mat- ter, we have gained the mastery of almost everything which exists on the surface of the earth, excepting ourselves. The science of the living beings in general, and especially of the human individual, has not made such great progress. It Still remains in the descriptive state. Man is an indivisible whole of extreme complexity. No simple representation of him can be obtained. There is no méthod capable of appre- hending him simultaneously in his entiréty, his parts, and his relations with the outer world. In order to analyze ourselves, we are obliged to seek the help of various tech- niques and, therefore, to utilize several sciences. Naturally, all these sciences arrive at a different conception of their common object. They abstract only from man what is at- tainable by their special méthods. And those abstractions, after they have been added together, are Still less rich than the concréte fact. They leave behind them a residue, too [2] THE NEED OF A BETTER KNOWLEDGE OF MAN important to be neglected. Anatomy, chemistry, physiology, psychology, pedagogy, history, sociology, political economy do not exhaust their subject. Man, as known to the spe- cialisis, is far from being the concréte man, the real man. He is nothing but a schema, consisting of other schemata built up by the techniques of each science. He is, at the same time, the corpse dissected by the anatomists, the con- sciousness observed by the psychologists and the great teach- ers of the spiritual life, and the personality which intro- spection shows to everyone as lying in the depth of himself. He is the chemical substances constituting the tissues and humors of the body. He is the amazing community of cells and nutrient fluids whose organic laws are studied by the physiologists. He is the compound of tissues and conscious- ness that hygienists and educators endeavor to lead to its optimum development while it extends into time. He is the homo e@conomicus who must ceaselessly consume manu- factured products in order that the machines, of which he is made a slave, may be kept at work. But he is also the poet, the hero, and the saint. He is not only the prodigiously complex being analyzed by our scientific techniques, but also the tendencies, the conjectures, the aspirations of hu- manity. Our conceptions of him are imbued with méta- physics. They are founded on so many and such imprecise data that the temptation is great to choose among them those which please us. Therefore, our idea of man varies according to our feelings and our beliefs. A materialist and a spiritualist accept the same definition of a crystal of sodium chloride. But they do not agree with one another upon that of the human being. A mechanistic physiologist and a vitalistic physiologist do not consider the organism [3] MAN, THE UNKNOWN in the same light. The living being of Jacques Loeb differs profoundly from that of Hans Driesch. Indeed, mankind has made a gigantic effort to know itself. Although we possess the treasure of the observations accumulated by the scientists, the philosophers, the poéts, and the great mystics of all times, we have grasped only certain aspects of our- selves. We do not apprehend man as a whole. We know him as composed of distinct parts. And even these parts are created by our méthods. Each one of us is made up of a procession of phantoms, in the midst of which Strides an unknowable reality. In fact, our ignorance is profound. Most of the questions put to themselves by those who study human beings remain without answer. Immense regions of our inner world are still unknown. How do the molecules of chemical sub- Stances associate in order to form the complex and tem- porary organs of the cell? How do the genes contained in the nucleus of a fertilized ovum détermine the character- istics of the individual deriving from that ovum? How do cells organize themselves by their own efforts into sociéties, such as the tissues and the organs? Like the ants and the bees, they have advance knowledge of the part they are destined to play in the life of the community. And hidden mechanisms enable them to build up an organism both complex and simple. What is the nature of our duration, of psychological time, and of physiological time? We know that we are a compound of tissues, organs, fluids, and con- sciousness. But the relations bétween consciousness and cerebrum are still a mystery. We lack almost entirely a knowledge of the physiology of nervous cells. To what ex- tent does will power modify the organism? How is the mind influenced by the state of the organs? In what manner can [4] THE NEED OF A BETTER KNOWLEDGE OF MAN the organic and mental characteristics, which each in- dividual inherits, be changed by the mode of life, the chemical substances contained in food, the climate, and the physiological and moral disciplines? We are very far from knowing what relations exist be- tween skeléton, muscles, and organs, and mental and spiritual activities. We are ignorant of the factors that bring about nervous equilibrium and resistance to fatigue and to diseases. We do not know how moral sense, judgment, and audacity could be augmented. What is the relative impor- tance of intellectual, moral, and mystical activities? What is the significance of esthétic and religious sense? What form of energy is responsible for telepathic communica- tions? Without any doubt, certain physiological and mental factors détermine happiness or misery, success or failure. But we do not know what they are. We cannot artificially give to any individual the aptitude for happiness. As yét, we do not know what environment is the most favorable for the optimum development of civilized man. Is it pos- sible to suppress struggle, effort, and suffering from our physiological and spiritual formation? How can we prevent the degeneracy of man in modern civilization? Many other questions could be asked on subjects which are to us of the utmost interest. They would also remain unanswered. It is quite evident that the accomplishments of all the sciences having man as an object remain insufficient, and that our knowledge of ourselves is still most rudimentary. 2 Our ignorance may be attributed, at the same time, to the mode of existence of our ancestors, to the complexity {5] MAN, THE UNKNOWN of our nature, and to the structure of our mind. Before all, man had to live. And that need demanded the conquest of the outer world. It was imperative to secure food and shelter, to fight wild animals and other men. For immense periods, our forefathers had neither the leisure nor the inclination to study themselves. ‘They employed their in- telligence in other ways, such as manufacturing weapons and tools, discovering fire, training cattle and horses, in- venting the wheel, the culture of cereals, étc., étc. Long before becoming interested in the constitution of their body and their mind, they meditated on the sun, the moon, the Stars, the tides, and the passing of the seasons. Astronomy was already far advanced at an epoch when physiology was totally unknown. Galileo reduced the earth, center of the world, to the rank of a humble satellite of the sun, while his contemporaries had not even the most elementary no- tion of the structure and the functions of brain, liver, or thyroid gland. As, under the natural conditions of life, the human organism works satisfactorily and needs no atten- tion, science progressed in the direction in which it was led by human curiosity—that is, toward the outer world. From time to time, among the billions of human beings who have successively inhabited the earth, a few were born endowed with rare and marvelous powers, the intuition of unknown things, the imagination that creates new worlds, and the faculty of discovering the hidden relations existing bétween certain phenomena. These men explored the physical universe. This universe is of a simple constitution. Therefore, it rapidly gave in to the attack of the scientists and yielded the secrét of certain of its laws. And the knowledge of these laws enabled us to utilize the world of [6] THE NEED OF A BETTER KNOWLEDGE OF MAM matter for our own profit. The practical applications of scientific discoveries are lucrative for those who promote them. They facilitate the existence of all. They please the public, whose comfort they augment. Everyone became, of course, much more interested in the inventions that lessen human effort, lighten the burden of the toiler, accelerate the rapidity of communications, and soften the harshness of life, than in the discoveries that throw some light on the intricate problems relating to the constitution of our body and of our consciousness. The conquest of the mate- rial world, which has ceaselessly absorbed the attention and the will of men, caused the organic and the spiritual world to fall into almost complete oblivion. In fact, the knowledge of our surroundings was indispensable, but that of our own nature appeared to be much less immediately useful. How- ever, disease, pain, death, and more or less obscure aspira- tions toward a hidden power transcending the visible uni- verse, drew the attention of men, in some measure, to the inner world of their body and their mind. At first, medicine contented itself with the practical problem of relieving the sick by empiric recipes. It realized only in recent times that the most effective méthod of preventing or curing illness is to acquire a complete understanding of the normal and diseased body—that is, to construct the sciences that are called anatomy, biological chemistry, physiology, and pa- thology. However, the mystery of our existence, the moral sufferings, the craving for the unknown, and the méta- psychical phenomena appeared to our ancestors as more important than bodily pain and diseases. The study of spiritual life and of philosophy attracted greater men than the study of medicine. The laws of mysticity became known [7] MAN, THE UNKNOWN before those of physiology. But such laws were brought to light only when mankind had acquired sufficient leisure to turn a little of his attention to other things than the con- quest of the outer world. There is another reason for the slow progress of the knowl. edge of ourselves. Our mind is so constructed as to delight in contemplating simple facts. We feel a kind of repugnance in attacking such a complex problem as that of the con- stitution of living beings and of man. The intellect, as Bergson wrote, is characterized by a natural inability to comprehend life. On the contrary, we love to discover in the cosmos the geométrical forms that exist in the depths of our consciousness. ‘The exactitude of the proportions of our monuments and the precision of our machines express a fundamental character of our mind. Geométry does not exist in the earthly world. It has originated in ourselves. The methods of nature are never so precise as those of man. We do not find in the universe the clearness and accuracy of our thought. We attempt, therefore, to abstract from the com- plexity of phenomena some simple systems whose com- ponents bear to one another certain relations susceptible of being described mathematically. This power of abstraction of the human intellect is responsible for the amazing progress of physics and chemistry. A similar success has rewarded the physicochemical study of living beings. The laws of chemistry and of physics are identical in the world of living things and in that of inanimate matter, as Claude Bernard thought Jong ago. This fact explains why modern physiology has dis- covered, for example, that the constancy of the alkalinity of the blood and of the water of the ocean is expressed by identical laws, that the energy spent by the contracting [8] THE NEED OF A BETTER KNOWLEDGE OF MAN muscle is supplied by the fermentation of sugar, étc. The physicochemical aspects of human beings are almost as easy to investigate as those of the other objects of the terrestrial world. Such is the task which general physiology succeeds in accomplishing. The study of the truly physiological phenomena—that is, of those resulting from the organization of living matter— mects with more important obstacles. On account of the ex- treme smallness of the things to be analyzed, it is impossible to use the ordinary techniques of physics and of chemistry. What method could bring to light the chemical constitution of the nucleus of the sexual cells, of its chromosomes, and of the genes that compose these chromosomes? Nevertheless, those very minute aggregates of chemicals are of capital im- portance, because they contain the future of the individual and of the race. The fragility of certain tissues, such as the nervous substance, is so great that to study them in the living state is almost impossible. We do not possess any technique capable of penetrating the mysteries of the brain, and of the harmonious association of its cells. Our mind, which loves the simple beauty of mathematical formulas, is bewildered when it contemplates the stupendous mass of cells, humors, and consciousness which make up the individual. We try, therefore, to apply to this compound the concepts that have proved useful in the realm of physics, chemistry, and me. chanics, and in the philosophical and religious disciplines, Such an attempt does not meét with much success, because we can be reduced neither to a physicochemical system nor to a spiritual entity. Of course, the science of man has to use the concepts of all the other sciences. But it must also [9 | MAN, THE UNKNOWN develop its own. For it is as fundamental as the sciences of the molecules, the atoms, and the electrons. In short, the slow progress of the knowledge of the human being, as compared with the splendid ascension of physics, astronomy, chemistry, and mechanics, is due to our ancestors’ lack of leisure, to the complexity of the subject, and to the Structure of our mind. Those obstacles are fundamental. There is no hope of eliminating them. They will always have to be overcome at the cost of strenuous effort. The knowl- edge of ourselves will never attain the elegant simplicity, the abstractness, and the beauty of physics. The factors that have rétarded its development are not likely to vanish. We must realize clearly that the science of man is the most difficult of all sciences. 3 The environment which has molded the body and the soul of our ancestors during many millenniums has now been replaced by another. This silent revolution has taken place almost without our noticing it. We have not realized its importance. Nevertheless, it is one of the most dramatic events in the history of humanity. For any modification in their surroundings inevitably and profoundly disturbs all living beings. We must, therefore, ascertain the extent of the transformations imposed by science upon the ancestral mode of life, and consequently upon ourselves. Since the advent of industry, a large part of the population has been compelled to live in restricted areas. The workmen are herded together, either in the suburbs of the large cities or in villages built for them. They are occupied in the fac- [10] THE NEED OF A BETTER KNOWLEDGE OF MAN tories during fixed hours, doing easy, monotonous, and well- paid work. The cities are also inhabited by office workers, employees of stores, banks, and public administrations, physicians, lawyers, school-teachers, and the multitude of those who, directly or indirectly, draw their livelihood from commerce and industry. Factories and offices are large, well lighted, clean. Their temperature is uniform. Modern heat- ing and refrigerating apparatuses raise the temperature dur- ing the winter and lower it during the summer. The sky- scrapers of the great cities have transformed the streéts into gloomy canyons. But inside of the buildings, the light of the sun is replaced by electric bulbs rich in ultra-violét rays. In- Stead of the air of the streét, polluted by gasoline fumes, the offices and workshops receive pure air drawn in from the up- per atmosphere by ventilators on the roof. The dwellers of the modern city are protected against all inclemencies of the weather. But they are no longer able to live as did our an- cestors, near their workshops, their stores, or their offices. The wealthier inhabit the gigantic buildings of the main avenues. At the top of dizzy towers, the kings of the business world possess delightful homes, surrounded by trees, grass, and flowers. They live there, as sheltered from noise, dust, and all disturbances, as if they dwelt on the summit of a mountain. They are more completely isolated from the com- mon herd than were the feudal lords behind the walls and the moats of their fortified castles. ‘The less wealthy, even those with quite modest means, lodge in apartments whose comfort surpasses that which surrounded Louis XIV or Frederick the Great. Many have their residence far from the city. Each evening, express trains transport innumerable crowds to suburbs, where broad roads running bétween green [11] MAN, THE UNKNOWN Strips of grass and rows of trees are bordered with prétty and comfortable houses. ‘The workmen and the humblest em- ployees live in dwellings bétter appointed than those of the rich of former times. The heating apparatuses that auto- matically regulate the temperature of the houses, the bath- rooms, the refrigerators, the electric stoves, the domestic ma- chinery for preparing food and cleaning rooms, and the garages for the automobiles, give to the abode of everybody, not only in the city and the suburbs, but also in the country, a degree of comfort which previously was found only in that of very few privileged individuals. Simultaneously with the habitat, the mode of life has been transformed. This transformation is due chiefly to the in- crease in the rapidity of communications. Indeed, it is evi- dent that modern trains and steamers, airplanes, automobiles, telegraph, telephone, and wireless have modified the relations of men and of nations all over the world. Each individual does a great many more things than formerly. He takes part in a much larger number of events. Every day he comes into contact with more people. Quiét and unemployed moments are exceptional in his existence. The narrow groups of the family and of the parish have been dissolved. Intimacy no longer exists. For the life of the small group has been sub- Stituted that of the herd. Solitude is looked upon as a punish- ment or as a rare luxury. The frequent attendance at cinema, theatrical, or athlétic performances, the clubs, the meétings of all sorts, the gigantic universities, factories, department Stores, and hotels have engendered in all the habit of living in common. The telephone, the radio, and the gramophone records carry unceasingly the vulgarity of the crowd, as well as its pleasures and its psychology, into everyone’s house, [12] THE NEED OF A BETTER KNOWLEDGE OF MAN even in the most isolated and remote villages. Each in- dividual is always in direct or indirect communication with other human beings, and keeps himself constantly informed about the small or important events taking place in his town, or his city, or at the other end of the world. One hears the chimes of Westminster in the most rétired houses of the French countryside. Any farmer in Vermont, if it pleases him to do so, may listen to orators speaking in Berlin, Lon- don, or Paris. Everywhere, in the cities, as well as in the country, in private houses as in factories, in the workshop, on the roads, in the fields, and on the farms, machines have decreased the intensity of human effort. Today, it is not necessary to walk. Elevators have replaced stairs. Everybody rides in buses, motors, or street cars, even when the distance to be covered is very short. Natural bodily exercises, such as walking and running over rough ground, mountain-climbing, tilling the land by hand, clearing forests with the ax, working while exposed to rain, sun, wind, cold, or heat, have given place to well-regulated sports that involve almost no risk, and to machines that abolish muscular effort. Everywhere there are tennis-courts, golf-links, artificial skating-rinks, heated swimming-pools, and sheltered arenas where athlétes train and fight while protected against the inclemencies of the weather. In this manner all can develop their muscles with- out being subjected to the fatigue and the hardships involved in the exercises pertaining to a more primitive form of life. The aliments of our ancestors, which consisted chiefly of coarse flour, meat, and alcoholic drinks, have been replaced by much more delicate and varied food. Beef and mutton are no longer the staple foods. The principal elements of [13] MAN, THE UNKNOWN modern diét are milk, cream, butter, cereals refined by the elimination of the shells of the grain, fruits of tropical as well as of temperate countries, fresh or canned vegétables, salads, large quantities of sugar in the form of pies, candies, and puddings. Alcohol alone has kept its place. The food of children has undergone a profound change. It is now very artificial and abundant. The same may be said of the diét of adults. The regularity of the working-hours in offices and factories has entailed that of the meals. Owing to the wealth which was general until a few years ago, and to the decline in the religious spirit and in the observance of ritualistic fasts, human beings have never been fed so punctually and un- interruptedly. It is also to the wealth of the post-war period that the enormous diffusion of education is due. Everywhere, schools, colleges, and universities have been erected, and immediately invaded by vast crowds of students. Youth has understood the rôle of science in the modern world. “Knowledge is power,” wrote Bacon. All institutions of learning are devoted to the intellectual development of children and young peo- ple. At the same time, they give great attention to their physical condition. It is obvious that the main interest of these educational establishments consists in the promotion of mental and muscular strength. Science has demonstrated its usefulness in such an evident manner that it has obtained the first place in the curriculum. A great many young men and women submit themselves to its disciplines. Scientific institutions, universities, and industrial corporations have built so many laboratories that every scientific worker has a chance to make use of his particular knowledge. The mode of life of modern men is profoundly influenced [14] THE NEED OF A BETTER KNOWLEDGE OF MAN by hygiene and medicine and the principles resulting from the discoveries of Pasteur. The promulgation of the Pastorian doctrines has been an event of the highest importance to humanity. Their application rapidly led to the suppression of the great infectious diseases which periodically ravaged the civilized world, and of those endemic in each country. The necessity for cleanliness was demonstrated. Infantile mortality at once decreased. The average duration of life has augmented to an amazing extent and has reached fifty- nine years in the United States, and sixty-five years in New Zealand. People do not live longer, but more people live to be old. Hygiene has considerably increased the quantity of human beings. At the same time, medicine, by a bétter con- ception of the nature of diseases and a judicious application of surgical techniques, has extended its beneficent influence to the weak, the defective, those predisposed to microbial infections, to all who formerly could not endure the condi- tions of a rougher life. It has permitted civilization to multi- ply its human capital enormously. It has also given to each individual much greater security against pain and disease. The intellectual and moral surroundings in which we are immersed have equally been molded by science. There is a profound difference bétween the world that permeates the mind of modern men and the world wherein our ancestors lived. Before the intellectual victories that have brought us wealth and comfort, moral values have naturally given ground. Reason has swept away religious beliefs. The knowl- edge of the natural laws, and the power given us by this knowledge over the material world, and also over human beings, alone are of importance. Banks, universities, labora- tories, medical schools, hospitals, have become as beautiful [15] MAN, THE UNKNOWN as the Greek temples, the Gothic cathedrals, and the palaces of the Popes. Until the recent economic crisis, bank or rail- road presidents were the ideals of youth. The president of a great university still occupies a very high place in the esteem of the public because he dispenses science. And science is the mother of wealth, comfort, and health. However, the intellectual atmosphere, in which modern men live, rapidly changes. Financial magnates, professors, scientists, and eco- nomic experts are losing their hold over the public. The people of today are sufficiently educated to read newspapers and magazines, to listen to the speeches broadcasted by poli- ticians, business men, charlatans, and apostles. They are saturated with commercial, political, or social propaganda, whose techniques are becoming more and more perfect. At the same time they read articles and books wherein science and philosophy are popularized. Our universe, through the great discoveries of physics and astronomy, has acquired a marvelous grandeur. Each individual is able, if it so pleases him, to hear about the theories of Einstein, or to read the books of Eddington and of Jeans, the articles of Shapley and of Millikan. The public is as interested in the cosmic rays as in cinema stars and baseball-players. Everyone is aware that space is curved, that the world is composed of blind and unknown forces, that we are nothing but infinitely small particles on the surface of a grain of dust lost in the im- mensity of the cosmos, and that this cosmos is totally deprived of life and consciousness. Our universe is exclusively me- chanical. It cannot be otherwise, since it has been created from an unknown substratum by the techniques of physics and astronomy. Just as are all the surroundings of modern [16] THE NEED OF A BETTER KNOWLEDGE OF MAN men, it is the expression of the amazing development of the sciences of inert matter. 4 The profound changes imposed on the habits of men by the applications of science have occurred recently. In fact, we are Still in the midst of the industrial revolution. It is difficult, therefore, to know exactly how the substitution of an artificial mode of existence for the natural one and a com- pléte modification of their environment have acted upon civilized human beings. There is, however, no doubt that such an action has taken place. For every living thing de- pends intimately on its surroundings, and adapts itself to any modification of these surroundings by an appropriate change. We mutt, therefore, ascertain in what manner we have been influenced by the mode of life, the customs, the diét, the education, and the intellectual and moral habits imposed on us by modern civilization. Have we benefited by such progress? This momentous question can be answered only after a careful examination of the state of the nations which were the first to profit by the application of scientific discoveries. It is evident that men have joyfully welcomed modern civilization. They have abandoned the countryside and flocked to the cities and the factories. ‘They eagerly adopt the mode of life and the ways of acting and of thinking of the new era. They lay aside their old habits without hesita- tion, because these habits demand a greater effort. It is less fatiguing to work in a factory or an office than on a farm. But even in the country, new techniques have relieved the [17] MAN, THE UNKNOWN harshness of existence. Modern houses make life easier for everybody. By their comfort, their warmth, and their pleas- ant lighting, they give their inmates a feeling of rest and contentment. Their up-to-date appointments considerably decrease the labor that, in bygone days, housekeeping de- manded from women. Besides the lessening of muscular ef- fort and the possession of comfort, human beings have ac- cepted cheerfully the privilege of never being alone, of enjoying the innumerable distractions of the city, of living among huge crowds, of never thinking. They also appreciate being released, through a purely intellectual education, from the moral restraint imposed upon them by Puritan discipline and religious principles. In truth, modern life has sét them free. It incites them to acquire wealth by any and every pos- sible means, provided that these means do not lead them to jail. It opens to them all the countries of the earth. It has liberated them from all superstitions. It allows them the fre- quent excitation and the easy satisfaction of their sexual appetites. It does away with constraint, discipline, effort, everything that is inconvenient and laborious. The people, especially those belonging to the lower classes, are happier from a material standpoint than in former times. However, some of them progressively cease to appreciate the distrac- tions and the vulgar pleasures of modern life. Occasionally, their health does not permit them to continue indefinitely the alimentary, alcoholic, and sexual excesses to which they are led by the suppression of all discipline. Besides, they are haunted by the fear of losing their employment, their means of subsistence, their savings, their fortune. They are unable to satisfy the need for security that exists in the depth of each of us. In spite of social insurances, they feel uneasy about [18] THE NEED OF A BETTER KNOWLEDGE OF MAN their future. Those who are capable of thinking become discontented. It is certain, nevertheless, that health is improving. Not only has mortality decreased, but each individual is hand- somer, larger, and stronger. Today, children are much taller than their parents. An abundance of good food and physical exercises have augmented the size of the body and its mus- cular strength. Often the best athlétes at the international games come from the United States. In the athlétic teams of the American universities, there are many individuals who are really magnificent specimens of human beings. Un- der the present educational conditions, bones and muscles develop perfectly. America has succeeded in reproducing the most admirable forms of ancient beauty. However, the longevity of the men proficient in all kinds of sports and enjoying every advantage of modern life is not greater than that of their ancestors. It may even be less. ‘Their resistance to fatigue and worry seems to have decreased. It appears that the individuals accustomed to natural bodily exercise, to hardships, and to the inclemencies of the weather, as were their fathers, are capable of harder and more sustained efforts than our athlétes. We know that the products of modern education need much sleep, good food, and regular habits. Their nervous system is delicate. They do not endure the mode of existence in the large cities, the confinement in offices, the worries of business, and even the everyday difh- culties and sufferings of life. They easily break down. Per- haps the triumphs of hygiene, medicine, and modern educa- tion are not so advantageous as we are led to believe. We should also ask ourselves whéther there are no in- conveniences attached to the great decrease in the death rate [19] MAN, THE UNKNOWN during infancy and youth. In fact, the weak are saved as well as the Strong. Natural selection no longer plays its part. No one knows what will be the future of a race so well pro- tected by medical sciences. But we are confronted with much graver problems, which demand immediate solution. While infantile diarrhea, tuberculosis, diphtheria, typhoid fever, étc., are being eliminated, they are replaced by degenerative diseases. There are also a large number of affections of the nervous system and of the mind. In certain states the mul- titude of the insane confined in the asylums exceeds that of the patients kept in all other hospitals. Like insanity, nerv- ous disorders and intellectual weakness seem to have become more frequent. They are the most active factors of individual misery and of the destruction of families. Mental déteriora- tion is more dangerous for civilization than the infectious diseases to which hygienists and physicians have so far ex- clusively devoted their attention. In spite of the immense sums of money expended on the education of the children and the young people of the United States, the intellectual élite does not seem to have increased. The average man and woman are, without any doubt, better educated and, superficially at least, more refined. The taste for reading is greater. More reviews and books are bought by the public than in former times. ‘The number of people who are interested in science, létters, and art has grown. But most of them are chiefly attracted by the lowest form of liter- ature and by the imitations of science and of art. It seems that the excellent hygienic conditions in which children are reared, and the care lavished upon them in school, have not raised their intellectual and moral standards. There may possibly be some antagonism bétween their physical develop- [20] THE NEED OF A BETTER KNOWLEDGE OF MAN ment and their mental size. After all, we do not know whéther a larger Stature in a given race expresses a State of progress, as is assumed today, or of degeneracy. There is no doubt that children are much happier in the schools where compulsion has been suppressed, where they are allowed exclusively to study the subjects in which they are interested, where in- tellectual effort and voluntary attention are not exacted. What are the results of such an education? In modern civiliza- tion, the individual is characterized chiefly by a fairly great activity, entirely directed toward the practical side of life, by much ignorance, by a certain shrewdness, and by a kind of mental weakness which leaves him under the influence of the environment wherein he happens to be placed. It appears that intelligence itself gives way when character weakens. For this reason, perhaps, this quality, characteristic of France in former times, has so markedly failed in that coun- try. In the United States, the intellectual standard remains low, in spite of the increasing number of schools and uni- versities. Modern civilization seems to be incapable of producing people endowed with imagination, intelligence, and cour- age. In practically every country there is a decrease in the intellectual and moral caliber of those who carry the re- sponsibility of public affairs. The financial, industrial, and commercial organizations have reached a gigantic size. They are influenced not only by the conditions of the country where they are established, but also by the State of the neigh- boring countries and of the entire world. In all nations, economic and social conditions undergo extremely rapid changes. Nearly everywhere the existing form of government is again under discussion. The great democracies find them- [21] MAN, THE UNKNOWN selves face to face with formidable problems—problems con- cerning their very existence and demanding an immediate solution. And we realize that, despite the immense hopes which humanity has placed in modern civilization, such a civilization has failed in developing men of sufficient intelli- gence and audacity to guide it along the dangerous road on which it is Stumbling. Human beings have not grown so rapidly as the institutions sprung from their brains. It is chiefly the intellectual and moral deficiencies of the political leaders, and their ignorance, which endanger modern na- tions. Finally, we must ascertain how the new mode of life will influence the future of the race. ‘The response of the women to the modifications brought about in the ancestral habits by industrial civilization has been immediate and decisive. The birth rate has at once fallen. This event has been felt most precociously and seriously in the social classes and in the nations which were the first to benefit from the progress brought about, directly or indirectly, by the applications of scientific discoveries. Voluntary sterility 1s not a new thing in the history of the world. It has already been observed in a certain period of past civilizations. It is a classical symptom. We know its significance. It is evident, then, that the changes produced in our en- vironment by technology have influenced us profoundly. Their effects assume an unexpected character. They are Strikingly different from those which were hoped for and which could legitimately be expected from the improve- ments of all kinds brought to the habitat, the mode of life, the diét, the education, and the intellectual atmosphere of [22] THE NEED OF A BETTER KNOWLEDGE OF MAN human beings. How has such a paradoxical result been obtained? 5 A simple answer could be given to this question. Modern civilization finds itself in a difficult position because it does not suit us. It has been erected without any knowledge of our real nature. It was born from the whims of scientific discoveries, from the appétites of men, their illusions, their theories, and their desires. Although constructed by our ef- forts, it is not adjusted to our size and shape. Obviously, science follows no plan. It develops at random. Its progress depends on fortuitous conditions, such as the birth of men of genius, the form of their mind, the direction taken by their curiosity. It is not at all actuated by a desire to improve the state of human beings. The discoveries re- sponsible for industrial civilization were brought forth at the fancy of the scientists’ intuitions and of the more or less casual circumstances of their careers. If Galileo, Newton, or Lavoisier had applied their intellectual powers to the Study of body and consciousness, our world probably would be different today. Men of science do not know where they are going. They are guided by chance, by subtle reasoning, by a sort of clairvoyance. Each one of them is a world apart, governed by his own laws. From time to time, things obscure to others become clear to him. In general, discoveries are developed without any prevision of their consequences. These consequences, however, have revolutionized the world and made our civilization what it is. From the wealth of science we have selected certain parts. [23] MAN, THE UNKNOWN And our choice has in no way been influenced by a considera- tion of the higher interests of humanity. It has simply fol- lowed the direction of our natural tendencies. The prin- ciples of the greatest convenience and of the least effort, the pleasure procured by speed, change, and comfort, and also the need of escaping from ourselves, are the détermining factors in the success of new inventions. But no one has ever asked himself how we would stand the enormous accelera- tion of the rhythm of life resulting from rapid transportation, telegraph, telephone, modern business méthods, machines that write and calculate, and those that do all the housekeep- ing drudgery of former times. The tendency responsible for the universal adoption of the airplane, the automobile, the cinema, the telephone, the radio, and, in the near future, of television, is as natural as that which, in the night of the ages, led our ancestors to drink alcohol. Steam-heated houses, electric lighting, elevators, biological morals, and chemical adulteration of foodstuffs have been accepted solely because those innovations were agreeable and convenient. But no account whatever has been taken of their probable effect on human beings. In the organization of industrial life the influence of the factory upon the physiological and mental state of the work- ers has been completely neglected. Modern indusiry is based on the conception of the maximum production at lowest cost, in order that an individual or a group of individuals may earn as much money as possible. It has expanded without any idea of the true nature of the human beings who run the machines, and without giving any consideration to the effects produced on the individuals and on their descendants by the artificial mode of existence imposed by the factory. The [24] THE NEED OF A BETTER KNOWLEDGE OF MAN great cities have been built with no regard for us. The shape and dimensions of the skyscrapers depend entirely on the necessity of obtaining the maximum income per square foot of ground, and of offering to the tenants offices and apart- ments that please them. This caused the construction of gigantic buildings where too large masses of human beings are crowded togéther. Civilized men like such a way of liv- ing. While they enjoy the comfort and bznal luxury of their dwelling, they do not realize that they are deprived of the necessities of life. The modern city consists of monstrous edifices and of dark, narrow Streéts full of gasoline fumes, coal dust, and toxic gases, torn by the noise of the taxicabs, trucks, and trolleys, and thronged ceaselessly by great crowds. Obviously, it has not been planned for the good of its inhabi- tants. Our life is influenced in a large measure by commercial advertising. Such publicity is undertaken only in the interest of the advertisers and not of the consumers. For example, the public has been made to believe that white bread is bétter than brown. Then, flour has been bolted more and more thoroughly and thus deprived of its most useful com- ponents. Such treatment permits its preservation for longer periods and facilitates the making of bread. The millers and the bakers earn more money. The consumers eat an inferior product, believing it to be a superior one. And in the coun- tries where bread is the principal food, the population degenerates. Enormous amounts of money are spent for pub- licity. As a result, large quantities of alimentary and pharma- ceutical products, at the least useless, and often harmful, have become a necessity for civilized men. In this manner the greediness of individuals, sufficiently shrewd to create a [25] MAN, THE UNKNOWN popular demand for the goods that they have for sale, plays a leading part in the modern world. However, the propaganda that directs our ways of living is not always inspired by selfish motives. Instead of being prompted by the financial interests of individuals or of groups of individuals, it often aims at the common good. But its effect may also be harmful when it emanates from people having a false or incompléte conception of the human being. For example, should physicians, by prescribing special foods, as most of them do, accelerate the growth of young children? In such an instance, their action is based on an incomplete knowledge of the subject. Are larger and heavier children bétter than smaller ones? Intelligence, alertness, audacity, and resistance to disease do not depend on the same factors as the weight of the body. The education dispensed by schools and universities consists chiefly in a training of the memory and of the muscles, in certain social manners, in a worship of athlétics. Are such disciplines really suitable for modern men who need, above all other things, mental equilibrium, nerv- ous Stability, sound judgment, audacity, moral courage, and endurance? Why do hygienists behave as though human beings were exclusively liable to infectious diseases, while they are also exposed to the attacks of nervous and mental disorders, and to the weakening of the mind? Although physicians, educators, and hygienists most generously lavish their efforts for the benefit of mankind, they do not attain their goal. For they deal with schemata containing only a part of the reality. The same may be said of all those who substitute their desires, their dreams, or their doctrines for the concrete human being. These theorists build up civiliza- [26] THE NEED OF A BETTER KNOWLEDGE OF MAN tions which, although designed by them for man, fit only an incompléte or monstrous image of man. The systems of government, entirely constructed in the minds of doc- trinaires, are valueless. ‘The principles of the French Revolu- tion, the visions of Marx and Lenin, apply only to abstract men. It must be clearly realized that the laws of human re- lations are still unknown. Sociology and economics are con- jectural sciences—that is, pseudo-sciences. Thus, it appears that the environment, which science and technology have succeeded in developing for man, does not suit him, because it has been constructed at random, with- out regard for his true self. 6 To summarize. The sciences of inert matter have made immense progress, while those of living beings remain in a rudimentary state. The slow advance of biology is due to the conditions of human existence, to the intricacy of the phenomena of life, and to the form of our intelligence, which delights in mechanical constructions and mathematical abstractions. The applications of scientific discoveries have transformed the material and mental worlds. These trans- formations exert on us a profound influence. Their un- fortunate effect comes from the fact that they have been made without consideration for our nature. Our ignorance of ourselves has given to mechanics, physics, and chemistry the power to modify at random the ancestral forms of life. Man should be the measure of all. On the contrary, he is a Stranger in the world that he has created. He has been in- [27] MAN, THE UNKNOWN capable of organizing this world for himself, because he did not possess a practical knowledge of his own nature. Thus, the enormous advance gained by the sciences of inanimate matter over those of living things is one of the greatest catas- trophes ever suffered by humanity. The environment born of our intelligence and our inventions is adjusted neither to our stature nor to our shape. We are unhappy. We degener- ate morally and mentally. The groups and the nations in which industrial civilization has attained its highest develop- ment are precisely those which are becoming weaker. And whose return to barbarism is the most rapid. But they do not realize it. They are without protection against the hostile surroundings that science has built about them. In truth, our civilization, like those preceding it, has created certain conditions of existence which, for reasons still obscure, ren- der life itself impossible. The anxiéty and the woes of the inhabitants of the modern city arise from their political, economic, and social institutions, but, above all, from their own weakness. We are the victims of the backwardness of the sciences of life over those of matter. The only possible remedy for this evil is a much more profound knowledge of ourselves. Such a knowledge will enable us to understand by what mechanisms modern exist- ence affects our consciousness and our body. We shall thus learn how to adapt ourselves to our surroundings, and how to change them, should a revolution become indispensable. In bringing to light our true nature, our potentialities, and the way to actualize them, this science will give us the explana- tion of our physiological weakening, and of our moral and intellectual diseases. We have no other means of learning the inexorable rules of our organic and spiritual activities, of [28] THE NEED OF A BETTER KNOWLEDGE OF MAN distinguishing the prohibited from the lawful, of realizing that we are not free to modify, according to our fancy, our environment, and ourselves. Since the natural conditions of existence have been destroyed by modern civilization, the science of man has become the moŝt necessary of all sciences. [2g] Chapter II THE SCIENCE OF MAN 1. Necessity of a choice among the heterogeneous data concerning man. The operational concept of Bridgman. Its application to living beings. Confusion of concepts. Rejection of philosophical and scientific systems. Function of conjectures. 2. The need of a com- plete survey. Every aspect of man to receive attention. No exag- gerated importance to be given to any one part. Simple phenomena not to be preferred to complex ones. Unexplainable facts not to be ignored. Man in his entirety is within the jurisdiction of science. 3. The science of man is more important than all other sciences. Its analytic and synthetic character. 4. The analysis of man requires various techniques. Those techniques create body and soul, structure and functions, and divide the body into parts. The specialists. The need for non-specialized scientists. How to promote human biological research. 5. Technical difficulties en- countered in the study of man. Utilization of animals of high intelligence. How experiments of long duration should be or- ganized. 6. The character of a utilizable synthesis of our data about man. I Our ignorance of ourselves is of a peculiar nature. It does not arise from difficulty in procuring the necessary informa- tion, from its inaccuracy, or from its scarcity. On the con- trary, it is due to the extreme abundance and confusion of the data accumulated about itself by humanity during the course of the ages. Also to the division of man into an almost infinite number of fragments by the sciences that have en- [30] THE SCIENCE OF MAN deavored to Study his body and his consciousness. This knowl- edge, to a large extent, has not been utilized. In fact, it is barely utilizable. Its sterility manifests itself in the meager- ness of the classical abstractions, of the schemata that are the basis of medicine, hygiene, education, sociology, and politi- cal economy. There is, however, a living and rich reality buried in the enormous mass of definitions, observations, doctrines, desires, and dreams representing man’s efforts toward a knowledge of himself. In addition to the systems and speculations of scientists and philosophers, we have the positive results of the experience of past generations, and also a multitude of observations carried out with the spirit and, occasionally, with the techniques of science. But we must make a judicious choice from these héterogeneous things. Among the numerous concepts relating to the human being, some are mere logical constructs of our mind. We do not find in the outer world any being to whom they apply. The others are purely and simply the result of experience. They have been called by Bridgman operational concepts. An operational concept is equivalent to the operation or to the sét of operations involved in its acquisition. Indeed, all positive knowledge demands the use of a certain technique, of certain physical or mental operations. When we say that an object is one méter long, we mean that it has the same length as a rod of wood or of métal, whose dimension is, in its turn, equal to that of the standard méter kept at the Inter- national Bureau of Weights and Measures in Paris. It is quite evident that the things we can observe are the only ones we really know. In the foregoing example, the concept of length is synonymous with the measurement of such [31] MAN, THE UNKNOWN length. According to Bridgman, concepts dealing with things situated outside the experimental field are meaningless. Thus, a question has no signification if it is not possible to discover the operations permitting us to answer it. The precision of any concept whatsoever depends upon that of the operations by which it is acquired. If man is defined as a being composed of matter and consciousness, such a proposition is meaningless. For the relations bétween consciousness and bodily matter have not, so far, been brought into the experimental field. But an operational defi- nition is given of man when we consider him as an organism capable of manifesting physicochemical, physiological, and psychological activities. In biology, as in physics, the con- cepts which will always remain real, and must be the basis of science, are linked to certain méthods of observation. For example, our present idea of the cells of the cerebral cortex, their pyramidal body, their dendritic processes, and their smooth axon, results from the techniques invented by Ramon y Cajal. This is an operational concept. Such a concept will change only when new and more perfect techniques will be discovered. But to say that cerebral cells are the seat of mental processes 1s a worthless affirmation, for there is no possibility of observing the presence of mental processes in the body of cerebral cells. Operational concepts are the only solid foundation upon which we can build. From the im- mense fund of knowledge we possess about ourselves, we must select the data corresponding to what exists not only in our mind, but also in nature. We know that among the concepts relating to man, some are specific of him, others belong to all living beings, and Still others are those of chemistry, physics, and mechanics. [32] THE SCIENCE OF MAN There are as many systems of concepts as of strata in the organization of living matter. At the level of the electronic, atomic, and molecular structures found in man’s tissues, as well as in trees, stones, or clouds, the concepts of space-time continuum, energy, force, mass, entropy, should be used. And also those of osmotic tension, electric charge, ions, capillarity, permeability, diffusion. The concepts of micella, dispersion, adsorption, and flocculation appear at the level of the ma- terial aggregates larger than molecules. When the molecules and their combinations have erected tissue cells, and when these cells have associated togéther to form organs and organ- isms, the concepts of chromosome, gene, heredity, adaptation, physiological time, reflex, instinct, étc., must be added to those already mentioned. They are the very concepts of physiology. They exist simultaneously with the physicochemical con- cepts, but cannot be reduced to them. At the highest level of organization, in addition to electrons, atoms, molecules, cells, and tissues, we encounter a whole composed of organs, humors, and consciousness. ‘Then, physicochemical and phys- iological concepts become insufficient. To them we must join the psychological concepts characteristic of man, such as intelligence, moral sense, esthetic sense, and social sense. The principles of minimum effort and of maximum production or of maximum pleasure, the quest for liberty, for equality, étc., have to be substituted for the thermodynamic laws and those of adaptation. Each system of concepts can only be legitimately used in the domain of the science to which it belongs. The concepts of physics, chemistry, physiology, and psychology are applica- ble to the superposed levels of the bodily organization. But the concepts appropriate at one level should not be mingled [33] MAN, THE UNKNOWN indiscriminately with those specific of another. For exam- ple, the second law of thermodynamics, the law of dissipation of free energy, indispensable at the molecular level, is useless at the psychological level, where the principles of least effort and of maximum pleasure are applied. The concepts of capil- larity and of osmotic tension do not throw any light on problems pertaining to consciousness. It is nothing but word play to explain a psychological phenomenon in terms of cell physiology, or of quantum mechanics. However, the mechanistic physiologists of the ninéteenth century, and their disciples who still linger with us, have committed such an error in endeavoring to reduce man entirely to physical chemistry. This unjustified generalization of the results of sound experiments i is due to Orpea lization: Concepts should not be misused. They must be kept in their place in the hierarchy of sciences. The confusion in our knowledge of ourselves comes chiefly from the presence, among the positive facts, of the remains of scientific, philosophic, and religious systems. If our mind adheres to any system whatsoever, the aspect and the signifi- cance of concréte phenomena are changed. At all times, humanity has contemplated itself through glasses colored by doctrines, beliefs, and illusions. ‘These false or inexact ideas must be discarded. Long ago, Claude Bernard in his writings mentioned the necessity of gétting rid of philosophical and scientific systems as one would break the chains of intellec- tual slavery. But such freedom has not yét been attained. Biologists and, above all, educators, economists, and sociolo- gists, when facing extremely complex problems, have often yielded to the temptation to build up theories and afterwards [34] THE SCIENCE OF MAN to turn them into articles of faith. And their sciences have crystallized in formulas as rigid as the dogmas of a religion. We meét with troublesome reminders of such mistakes in all the departments of knowledge. The quarrel of the vital- ists and the mechanists, the futility of which astounds us today, arose from one of the most famous of these errors. The vitalists thought that the organism was a machine whose parts were integrated with one another by a factor that was not physicochemical. According to them, the processes re- sponsible for the unity of the living being were governed by an independent spiritual principle, an entelechy, an idea analogous to that of an engineer who designs a machine. This autonomous factor was not a form of energy and did not produce energy. It was only concerned with the manage- ment of the organism. Evidently, entelechy is not an opera- tional concept. It is purely a mental construct. In short, the vitalists considered the body as a machine, guided by an engi- neer, whom they called entelechy. And they did not realize that this engineer was nothing but the intelligence of the observer. As for the mechanists, they believed that all physi- ological and psychological activities could be explained by the laws of physics, chemistry, and mechanics. Theythus built a machine, and, like the vitalists, they were the engineer of this machine. Then, as Woodger pointed out, they forgot the existence of that engineer. Such a concept is not operational. It is evident that mechanism and vitalism should be rejected for the same reason as all other systems. At the same time, we must free ourselves from the mass of illusions, errors, and badly observed facts, from the false problems investigated by the weak-minded of the realm of science, and from the [35] MAN, THE UNKNOWN pseudo-discoveries of charlatans and scientists extolled by the daily press. Also from the sadly useless investigations, the long studies of meaningless things, the inextricable jumble that has been standing mountain high ever since biological research became a profession like those of the school-teacher, the clergyman, and the bank clerk. This elimination compléted, the results of the patient labor of all sciences concerning themselves with man, the accumulated wealth of their experience, will remain as the unshakable basis of our knowledge. In the history of human- ity, the expression of all our fundamental activities can be read at a single glance. In addition to positive observations, to sure facts, there are many things neither positive nor in- dubitable. They should not be rejected. Of course, opera- tional concepts are the only foundation upon which science can be solidly built. But creative imagination alone is capa- ble of inspiring conjectures and dreams pregnant with the worlds of the future. We must continue asking questions which, from the point of view of sound, scientific criticism, are meaningless. And even if we tried to prevent our mind from pursuing the impossible and the unknowable, such an effort would be vain. Curiosity is a necessity of our nature, a blind impulse that obeys no rule. Our mind turns around all external objects and penétrates within the depths of our- selves, as instinctively and as irresistibly as a raccoon ex- plores, with its clever little paws, the slightest détails of its narrow world. Curiosity impels us to discover the universe. It inexorably draws us in its train to unknown countries. And unclimbable mountains vanish before it like smoke be- fore the wind. [ 36] THE SCIENCE OF MAN 2 A thorough examination of man is indispensable. The barrenness of classical schemata is due to the fact that, despite the great scope of our knowledge, we have never appre- hended our whole being with a sufficiently penétrating ef- fort. Thus, we must do more than consider the aspect of man at a certain period of his history, in certain conditions of his life. We must grasp him in all his activities, those that are ordinarily apparent as well as those that may remain poten- tial. Such information can only be obtained by looking care- fully in the present and in the past for all the manifestations of our organic and mental powers. Also by an examination, both analytic and synthetic, of our constitution and of our physical, chemical, and mental relations with our environ- ment. We should follow the wise advice that Descartes, in his Discourse on Méthod, gave to those who seek the truth, and divide our subject into as many parts as are necessary in order to make a complete inventory of each one of them. But it should be clearly understood that such a division is only a methodological expedient, created by ourselves, and that man remains indivisible. There is no privileged territory. In the abysses of our inner world everything has a meaning. We cannot choose only those things that please us, according to the dictates of our feelings, our imagination, the scientific and philosophical form of our mind. A difficult or obscure subject must not be neglected just because it is difficult and obscure. All méthods should be employed. The qualitative is as true as the quantitative. The relations that can be expressed in [37] MAN, THE UNKNOWN mathematical terms do not possess greater reality than those that cannot be so expressed. Darwin, Claude Bernard, and Pasteur, whose discoveries could not be described in alge- braic formulas, were as great scientists as Newton and Ein- Stein. Reality is not necessarily clear and simple. It is not even sure that we are always able to understand it. In addi- tion, it assumes infinitely varied aspects. A state of conscious- ness, the humeral bone, a wound, are equally real things. A phenomenon does not owe its importance to the facility with which scientific techniques can be applied to its study. It must be conceived in function, not of the observer and his méthod, but of the subject, the human being. The grief of the mother who has lost her child, the distress of the mys- tical soul plunged in the “dark night,” the suffering of the patient tortured by cancer, are evident realities, although they are not measurable. The study of the phenomena of clairvoyance should not be neglected any more than that of the chronaxy of nerves, though clairvoyance can neither be produced at will nor measured, while it is possible to meas- ure chronaxy exactly by a simple méthod. In making this inventory, we should utilize all possible means and be con- tent with observing the phenomena that cannot be measured. It often happens that undue importance is given to some part at the expense of the others. We are obliged to consider all the different aspects of man, physicochemical, anatomical, physiological, métapsychical, intellectual, moral, artistic, re- ligious, economic, and social. Every specialist, owing to a well-known professional bias, believes that he understands the entire human being, while in reality he only grasps a tiny part of him. Fragmentary aspects are considered as repre- senting the whole. And these aspects are taken at random, [38] THE SCIENCE OF MAN following the fashion of the moment, which in turn gives more importance to the individual or to sociéty, to physio- logical appétites or to spiritual activities, to muscular devel- opment or to brain power, to beauty or to utility, étc. Man, therefore, appears with many different visages. We arbitra- rily choose among them the one that pleases us, and forgét the others. Another mistake consists in suppressing a part of reality from the inventory. ‘There are many reasons accounting for this. We prefer to study systems that can easily be isolated and approached by simple méthods. We generally neglect the more complex. Our mind has a partiality for precise and definitive solutions and for the resulting intellectual secu- rity. We have an almost irresistible tendency to select the sub- jects of our investigations for their technical facility and clearness rather than for their importance. ‘Thus, modern physiologists principally concern themselves with physico chemical phenomena taking place in living animals, and pay less attention to physiological and functional processes. The same thing happens with physicians when they special- ize in subjects whose techniques are easy and already known, rather than in degenerative diseases, neuroses, and psychoses, whose study would require the use of imagination and the creation of new méthods. Everyone realizes, however, that the discovery of some of the laws of the organization of living matter would be more important than, for example, that of the rhythm of the cilia of tracheal cells. Without any doubt, it would be much more useful to free humanity from cancer, tuberculosis, arteriosclerosis, syphilis, and the innumerable misfortunes caused by nervous and mental diseases, than to engross oneself in the minute study of physicochemical phe- [39] MAN, THE UNKNOWN nomena of secondary importance manifesting themselves in the course of diseases. On account of technical difficulties, certain matters are banished from the field of scientific re- search, and refused the right of making themselves known. Important facts may be completely ignored. Our mind has a natural tendency to reject the things that do not fit into the frame of the scientific or philosophical beliefs of our time. After all, scientists are only men. They are saturated with the prejudices of their environment and of their epoch. They willingly believe that facts that cannot be explained by current theories do not exist. During the period when phys- iology was identified with physical chemistry, the period of Jacques Loeb and of Bayliss, the study of mental functions was neglected. No one was interested in psychology and in mind disorders. At the present time, scientists who are con- cerned solely in the physical, chemical, and physicochemical aspects of physiological processes still look upon telepathy and other métapsychical phenomena as illusions. Evident facts having an unorthodox appearance are suppressed. By reason of these difficulties, the inventory of the things which could lead us to a bétter understanding of the human being, has been left incompléte. We must, then, go back to a naive observation of ourselves in all our aspects, reject nothing, and describe simply what we see. At first glance, the scientific méthod seems not to be ap- plicable to the analysis of all our activities. It is obvious that we, the observers, are unable to follow human person- ality into every region where it extends. Our techniques do not grasp things having neither dimensions nor weight. They only reach those situated in space and time. They are incapable of measuring vanity, hatred, love, beauty, or the [40] THE SCIENCE OF MAN dreams of the scientist, the inspiration of the poet, the eleva- tion of the mystical soul toward God. But they easily record the physiological aspects and the material results of these psychological states. Mental and spiritual activities, when they play an important part in our life, express themselves by a certain behavior, certain acts, a certain attitude toward our fellow men. It is only in this manner that the moral, esthétic, and mystic functions can be explored by scientific methods. We also have at our disposal the statements of those who have traveled in these almost unknown regions. But the verbal expression of their experiences is, in general, dis- concerting. Outside the domain of intelligence, nothing is clearly definable. Of course, the elusiveness of a thing does not signify its non-existence. When one sails in dense fog, the invisible rocks are none the less present. From time to time their menacing forms emerge from the white mist. And at once they are swallowed up again. To this phenomenon can be truthfully compared the evanescent visions of artists and, above all, of great mystics. Those things which our tech- niques are incapable of grasping nevertheless Stamp the in- itiated with a visible mark. In such indirect ways does science know the spiritual world which, by definition, it is forbidden to enter. Man in his entiréty is located within the jurisdic- tion of the scientific techniques. 3 The critical review of the data concerning man yields a large amount of positive information. We are thus enabled to make a complete inventory of human activities. Such an in- ventory will lead to the building up of new schemata, richer [41] MAN, THE UNKNOWN than the classical ones. But our knowledge will not, in this manner, progress very strikingly. We shall have to go farther and build up a real science of man. A science capable of un- dertaking, with the help of all known techniques, a more exhaustive examination of our inner world, and also of real- izing that each part should be considered as a function of the whole. In order to develop such a science, we mutt, for some time, turn our attention away from mechanical inven- tions and even, in a certain measure, from classical hygiene and medicine, from the purely material aspects of our ex- istence. Everybody is interested in things that increase wealth and comfort. But no one understands that the struc- tural, functional, and mental quality of each individual has to be improved. The health of the intelligence and of the affective sense, moral discipline, and spiritual development are just as necessary as the health of the body and the pre- vention of infectious diseases. No advantage is to be gained by increasing the number of mechanical inventions. It would perhaps be as well not to accord so much importance to discoveries of physics, astron- omy, and chemistry. In truth, pure science never directly brings us any harm. But when its fascinating beauty domi- nates our mind and enslaves our thoughts in the realm of inanimate matter, it becomes dangerous. Man must now turn his attention to himself, and to the cause of his moral and intellectual disability. What is the good of increasing the comfort, the luxury, the beauty, the size, and the com- plications of our civilization, if our weakness prevents us from guiding it to our best advantage? It is really not worth while to go on elaborating a way of living that is bringing about the demoralization and the disappearance of the [42] THE SCIENCE OF MAN noblest elements of the great races. It would be far bétter to pay more attention to ourselves than to construct faster steamers, more comfortable automobiles, cheaper radios, or telescopes for examining the structure of remote nebulez. What real progress will be accomplished when aircraft take us to Europe or to China in a few hours? Is it necessary to in- crease production unceasingly, so that men may consume larger and larger quantities of useless things? There is not the shadow of a doubt that mechanical, physical, and chem- ical sciences are incapable of giving us intelligence, moral discipline, health, nervous equilibrium, security, and peace. Our curiosity must turn aside from its present path, and take another direction. It must leave the physical and physi- ological in order to follow the mental and the spiritual. So far, sciences concerning themselves with human beings have confined their activities to certain aspects of their subject. They have not succeeded in escaping from Cartesian dual- ism. They have been dominated by mechanism. In physiol- ogy, hygiene, and medicine, as well as in the study of education and of political and social economy, scientists have been chiefly absorbed by organic, humoral, and intellectual aspects of man. They have not paid any great attention to his affective and moral form, his inner life, his character, his esthetic and religious needs, the common substratum of or- ganic and psychological activities, the intimate relations of the individual and of his mental and spiritual environment. A radical change is indispensable. This change requires both the work of specialists devoting their efforts to the particular knowledge related to our body and our mind, and of scien- tists capable of integrating the discoveries of the specialists in function of man as a whole. The new science must pro- [43] MAN, THE UNKNOWN gress, by a double effort of analysis and synthesis, toward a conception of the human individual at once sufficiently com- plete and sufficiently simple to serve as a basis for our action. 4 Man cannot be separated into parts. He would cease to exist if his organs were isolated from one another. Although indivisible, he assumes different aspects. His aspects are the héterogeneous manifestations of his unity to our sense or- gans. He can be compared to an electric lamp whose pres- ence is recorded in a different manner by a thermométer, a voltméter, a photographic plate, or a selenium cell. We are incapable of direclly apprehending him in his simplicity. We can only grasp him through our senses and our scientific instruments. According to our means of investigation, his activity appears to be physical, chemical, physiological, or psychological. The analysis of his manifoldness naturally de- mands the help of various techniques. As he manifests him- self exclusively through the agency of these techniques, he necessarily takes on the appearance of being multiple. The science of man makes use of all other sciences. ‘This 1s one of the reasons for its slow progress and its difficulty. For example, in order to study the influence of a psychological factor on a sensitive individual, the méthods of medicine, physiology, physics, and chemistry have to be employed. Lét us suppose that our subject receives bad news. This psycho- logical event may express itself simultaneously by moral suf- fering, nervous agitation, circulatory disturbances, lesions of the skin, physicochemical modifications of the blood, étc. When dealing with man we are obliged to employ the meth- [44] THE SCIENCE OF MAN ods and concepts of several sciences, even for the simplest experiment. If we study the effects of a given food, either animal or vegétable, on a group of individuals, we must first learn the chemical composition of that food. And also the physiological and psychological states, and the ancestral char- acteristics of the individuals who are to be the subjects of the investigation. Then we have to record accurately the changes in weight, in height, in the form of the skeléton, in muscular strength, in susceptibility to diseases, in the phys- ical, chemical, and anatomical characteristics of the blood, in nervous equilibrium, in intelligence, courage, fertility, lon- gevity, which take place during the course of the experiment. Obviously, no one scientist is capable of mastering all the techniques indispensable to the study of a single human problem. Therefore, progress in knowledge of ourselves re- quires the simultaneous efforts of various specialists. Each specialist confines himself to one part of the body, or con- sciousness, or of their relations with the environment. He is anatomist, physiologist, chemist, psychologist, physician, hygienist, educator, clergyman, sociologist, economist. Each speciality is divided into smaller and smaller parts. There are specialists in glandular physiology, in vitamines, in diseases of the rectum, in those of the nose, in education of small chil- dren or of adults, in hygiene of factories and of prisons, in psychology of all categories of individuals, in domestic econ- omy, rural economy, étc. Such a division of the work has made possible the development of the particular sciences. Specialization is imperative. Scientists have to devote their attention to one department of knowledge. And it is impos- sible for a specialist, actively engaged in the pursuit of his own task, to understand the human being as a whole. Indeed, [45] MAN, THE UNKNOWN such a state of affairs is rendered necessary by the vast extent of the field of each science. But it presents a certain danger. For example, Calmétte, who had specialized in bacteriology, wished to prevent the spread of tuberculosis among the French population. He, naturally, prescribed the use of the vaccine he had invented. If, in addition to being a bacteri- ologist, he had possessed a moregeneral knowledge of hygiene and medicine, he would have advised also the adoption of measures with regard to dwellings, food, working conditions, and the way of living of the people. A similar occurrence took place in the United States in the organization of the ele- mentary schools. John Dewey,)who is a philosopher, under- took to improve The education of American children. But his méthods were suited to the schema, the abstraction, which his professional bias made him take for the concrete child. Still more harm is caused by the extreme specialization of the physicians. Medicine has separated the sick human being into small fragments, and each fragment has its spe- cialist. When a specialist, from the beginning of his career, confines himself to a minute part of the body, his knowledge of the rest is so rudimentary that he is incapable of thor- oughly understanding even that part in which he specializes. A similar thing happens to educators, clergymen, econo- mists, and sociologists who, before limiting themselves en- tirely to their particular domain, have not taken the trouble _to acquire a general knowledge of man. The more eminent the specialist, the more dangerous he is. Scientists who have Strikingly distinguished themselves by great discoveries or useful inventions often come to believe that their knowledge of one subject extends to all others. Edison, for example, did not hesitate to impart to the public his views on philosophy [46] THE SCIENCE OF MAN and religion. And the public listened to his words with re- spect, imagining them to carry as much weight on these new subjects as on the former ones. ‘Thus, great men, in speaking about things they do not thoroughly understand, hinder human progress in one of its fields, while having contributed to its advancement in another. The daily press often gives us the dubious benefit of the sociological, economic, and scien- tific opinions of manufacturers, bankers, lawyers, professors, physicians, whose highly specialized minds are incapable of apprehending in their breadth the momentous problems of our time. However, modern civilization absolutely needs spe- cialists. Without them, science could not progress. But, be- fore the result of their researches is applied to man, the scattered data of their analyses must be integrated in an in- telligible synthesis. Such a synthesis cannot be obtained by a simple round- table conference of the specialists. It requires the efforts of one man, not merely those of a group. A work of art has never been produced by a committee of artists, nor a great discov- ery made by a committee of scholars. ‘The syntheses needed for the progress of our knowledge of man should be elabo- rated in a single brain. It is impossible to make use of the mass of information accumulated by the specialists. For no one has undertaken to codrdinate the data already obtained, and to consider the human being in his entiréty. ‘Today there are many scientific workers, but very few real scientists. This peculiar situation is not due to lack of individuals capable of high intellectual achievements. Indeed, syntheses, as well as discoveries, demand exceptional mental power and physio- logical endurance. Broad and strong minds are rarer than precise and narrow ones. It is easy to become a good chemist, [47] MAN, THE UNKNOWN a good physicist, a good physiologist, a good psychologist, or a good sociologist. On the contrary, very few individuals are capable of acquiring and using knowledge of several differ- ent sciences. However, such men do exist. Some of those whom our scientific institutions and universities have forced to specialize narrowly could apprehend a complex subject both in its entirety and in its parts. So far, scientific workers devoting themselves, within a minute field, to prolonged Study of a generally insignificant détail, have always been the most favored. An original piece of work, without any real importance, 1s considered of greater value than a thorough knowledge of an entire science. Presidents of universities and their advisers do not realize that synthétic minds are as indispensable as analytic ones. If the superiority of this kind of intellect were recognized, and its development encour- aged, specialists would cease to be dangerous. For the sig- nificance of the parts in the organization of the whole could then be correctly estimated. At the beginning of its history more than at its zenith a science needs superior minds. To become a great physician requires more imagination, judgment, and intelligence than to become a great chemist. At the present time our knowl- edge of man can only progress by attracting a powerful intel- lectual élite. Great mental capacities should be required from the young men who desire to devote themselves to biol- ogy. It seems that the increased number of scientific work- ers, their being split up into groups whose studies are lim- ited to a small subject, and over-specialization have brought about a shrinking of intelligence. There is no doubt that the quality of any human group decreases when the number of the individuals composing this group increases beyond cer- [48] THE SCIENCE OF MAN tain limits. The Supreme Court of the United States con- sists of nine men whose professional value and character are truly eminent. But if it were composed of nine hundred jurists instead of nine, the public would immediately lose, and rightly, its respect for the highest court of this country. The best way to increase the intelligence of scientists would be to decrease their number. After all, the knowledge of man could be developed by a very small group of workers, pro- vided that they were endowed with creative imagination and given powerful means for carrying out their researches. Great sums of money are wasted every year on scientific re- search, in America as well as in Europe, because those who are entrusted with this work do not generally possess the qualities necessary to the conquerors of new worlds. And also because the few individuals endowed with this excep- tional power live under conditions precluding intellectual creation. Neither laboratories, nor apparatus, nor organiza- tion can give to scientists the surroundings indispensable to their success. Modern life is opposed to the life of the mind. However, men of science have to be mere units of a herd whose appetites are purely material and whose habits are entirely different from theirs. They vainly exhaust their Strength and spend their time in the pursuit of the condi- tions demanded by the elaboration of thought. No one of them is wealthy enough to procure the isolation and the silence which in former times everybody could have for nothing, even in the largest cities. No attempt has so far been made to create, in the midst of the agitation of the new city, islands of solitude where meditation would be possible. Such an innovation, however, is an obvious necessity. The construction of vast syntheses is beyond the reach of minds [49] MAN, THE UNKNOWN unceasingly dispersed in the confusion of our present modes of existence. The development of the science of man, even more than that of the other sciences, depends on immense intellectual effort. The need of such an effort demands a revision, not only of our conception of the scientist, but also of the conditions under which scientific research is car- ried on. 5 Human beings are not good subjects for scientific investi- gation. One does not easily find people with identical char- acteristics. It is almost impossible to verify the results of an experiment by referring the subject to a sufficiently similar control. Lét us suppose, for example, that we wish to com- pare two methods of education. For such a study we choose two groups of children, as nearly alike as possible. If these children, although of the same age and the same size, belong to different social classes, if their food is not the same, if they live in different psychological atmospheres, the results can- not be compared. In a like manner, the effects of two modes of life on children belonging to one family have little value. For, human races not being pure, there are often profound differences bétween the offspring of the same parents. On the contrary, the results will be conclusive when the chil- dren, whose behavior is compared under different condi- tions, are twins from a single ovum. We are generally obliged to be content with approximate information. This is one of the factors that have impeded the progress of the science of man. In researches dealing with physics and chemistry, and also [50] THE SCIENCE OF MAN with physiology, one always attempts to isolate relatively simple systems, and to détermine their exact conditions. But when the human being has to be studied as an entiréty, and in his relations with his environment, such a limitation of the subject is impossible. ‘The observer must be endowed with sound judgment in order not to lose his way in the complexity of the facts. The difficulties become almost in- surmountable in rétrospective investigations. Such studies require a very experienced mind. Of course, we should as rarely as possible utilize the conjectural science which is called history. But there have been in the past certain events, revealing the existence in man of extraordinary potentiali- ties. A knowledge of the genesis of these qualities would be of great importance. What factors caused, during the epoch of Pericles, the simultaneous appearance of so many gen- iuses? A similar event occurred at the time of the Renais- sance. Whence sprang the immense expansion, not only of intelligence, scientific imagination, and esthétic intuition, but also of physical vigor, audacity, and the spirit of adven- ture in the men of this period? Why did they possess such mighty physiological and mental activities? One easily real- izes how useful would be precise information regarding the mode of life, the food, the education, the intellectual, moral, esthetic, and religious surroundings of the people who lived during the time immediately preceding the appearance of a pleiad of great men. Another cause of the difficulties in experimenting on human beings is the fact that the observer and his subject live at about the same rhythm. The effects of a certain diet, of an intellectual or moral discipline, of political or social changes, are felt but slowly. It is only after a lapse of thirty or [51] MAN, THE UNKNOWN forty years that the value of an educational méthod can be estimated. The influence of a given mode of living upon the physiological and mental activities of a human group does not manifest itself before a generation has passed. Inventors of new systems of diét, physical culture, hygiene, education, morals, social economy, are always too early in publishing the success of their own inventions. It is only now that the result of the Montessori system, or of the educational prin- ciples of John Dewey, could be profitably analyzed. We should wait another quarter of a century to know the sig- nificance of the intelligence tests which psychologists have made in the schools during these past years. The only way to ascertain the effect of a given factor on man is to follow a great number of individuals through the vicissitudes of their life right up to their death. And even then the knowledge thus obtained will be grossly approximate. The progress of humanity appears to us to be very slow because we, the observers, are units of the herd. Each one of us can make but few observations. Our life is too short. Many experiments should be conducted for a century at the least. Institutions should be established in such a way that observations and experiments commenced by one scientist would not be interrupted by his death. Such organizations are Still unknown in the realm of science. But they already exist in other lines of endeavor. In the monastery of Solesmes three successive generations of Benedictine monks have de- voted themselves, over a period of about fifty-five years, to the reconstruction of Gregorian music. A similar méthod should be applied to the investigation of certain problems of human biology. Institutions, in some measure immortal, like religious orders, which would allow the uninterrupted [52] THE SCIENCE OF MAN continuation of an experiment as long as might be necessary, should compensate for the too short duration of the existence of individual observers. Certain data, urgently needed, can be procured with the help of short-lived animals. For this purpose, mice and rats have been chiefly used. Colonies consisting of many thou- sands of these animals have been employed to study different diets, their influence on the rapidity of growth, on size, dis- ease, longevity, étc. Unfortunately, rats and mice have only very remote analogies with man. It is dangerous, for exam- ple, to apply to children, whose constitution is so different, conclusions of researches made on these animals. Besides, the mental states accompanying anatomical and functional changes in bones, tissues, and humors under the influence of food and mode of life, cannot be properly investigated on such low types of animals. By observing more intelligent animals, such as monkeys and dogs, one would obtain more détailed and important information. Monkeys, despite their cerebral development, are not good subjects for experimentation. Their pedigree is not available. They cannot be bred easily or in sufficiently large numbers. They are difficult to handle. On the contrary, intelligent dogs can be procured readily. Their ancestral character- istics are easily traced. Such animals propagate rapidly. They mature in a year. Generally, they do not live beyond fifteen years. Détailed psychological observations can be made with- out trouble, especially on shepherd dogs, which are sensitive, intelligent, alert, and attentive. With the aid of these animals of pure breed, and in sufficient number, the complex and important problem of the influence of environment on the individual could be elucidated. For example, we should [53] MAN, THE UNKNOWN ascertain whether the increase in stature, which is taking place in the population of the United States, is an advantage or a disadvantage. It is also imperative to know what effect modern life and food have on the nervous system of children, and on their intelligence, alertness, and audacity. An exten- sive experiment carried out on several hundred dogs over a period of twenty years would give some precise information on these subjects, which are of paramount importance to millions of people. It would indicate, more rapidly than the observation of human beings, in what direction the diét and mode of living of the population should be changed. Such study would effectively supplement the incompléte and brief experiments which now appear to satisfy nutrition spe- cialists. However, the observation of even the highest type of animal cannot entirely replace that of man. In order to develop definitive knowledge, experiments on groups of human beings should be started under such conditions that they could be continued by several generations of scientists. 6 A bétter knowledge of ourselves cannot be acquired merely by selecting positive facts in the mass of information con- cerning man, and by making a complete inventory of his activities. Neither would the completion of these data by new observations and experiments, and the building up of a true science of man be sufficient. Above all, we need a synthesis that can be utilized. ‘The purpose of this knowledge is not to satisfy our curiosity, but to rebuild ourselves and our surroundings. Such a purpose is essentially practical. The acquisition of a large quantity of new data, if these data [54] THE SCIENCE OF MAN remain scattered in the brains and in the books of special- ists, is absolutely useless. A dictionary does not confer a lit- erary or philosophical culture upon its owner. Our ideas must be assembled as a living whole, within the intelligence and the memory of a few superior individuals. ‘Thus, the ef- forts which humanity has made, and is ceaselessly making, to attain a bétter knowledge of itself would become productive. The science of man will be the task of the future. We must now be content with an initiation, both analytic and synthetic, into those characteristics of the human being which scientific criticism has demonstrated to be true. In the following pages man will appear to us as naively as to the observer and to his techniques. We shall view him in the form of fragments carved by these techniques. But as far as is possible, these fragments will be replaced in the whole. Such knowledge is, of course, most inadequate. But it is cer- tain. It contains no métaphysical elements. It is also em- pirical, because no principle governs the choice and the order of the observations. We do not seek to prove or to dis- prove any theory. The different aspects of man are consid. ered as simply as, when ascending a mountain, one considers the rocks, torrents, meadows, and pines, and even, above the shadows of the valley, the light of the peaks. In both cases, the observations are made as the chances of the way decide. These observations are, however, scientific. They constitute a more or less syStematized body of knowledge. Naturally, they do not have the precision of those of astronomers and physicists. But they are as exact as is permitted by the tech- niques employed, and the nature of the object to which the techniques are applied. For instance, we know that men are endowed with memory and esthetic sense. Also that the pan- [55] MAN, THE UNKNOWN creas secretes insulin, that certain mental diseases depend on lesions of the brain, that some individuals manifest phe- nomena of clairvoyance. Memory, and the activity of in- sulin can be measured. But not esthétic emotion or moral sense. The characteristics of telepathy, or the relations be- tween mental diseases and the brain, lend themselves Still less to exact study. Nevertheless, all these data, although ap- proximate, are sure. This knowledge may be reproached with being common- place and incompléte. It is commonplace because body and consciousness, duration, adaptation, and individuality are well known to specialists in anatomy, physiology, psychology, métapsychics, hygiene, medicine, education, religion, and sociology. It is incompléte because a choice had to be made among an immense number of facts. And such a choice is bound to be arbitrary. It is limited to what appears to be most important. The rest is neglected, for a synthesis should be short and understandable at a single glance. Human in- telligence is capable of rétaining only a certain number of détails. It would, then, seem that our knowledge of man, in order to be useful, must be incompléte. The likeness of a portrait is due to the selection of détails, and not to their number. A drawing more forcibly expresses the character of an individual than a photograph does. We are going to trace only rough skétches of ourselves, similar to anatomical figures chalked on a blackboard. Our skétches will be true, in spite of the intentional suppression of détails. They will be based on positive data and not on theories and dreams. They will ignore vitalism and mechanism, realism and nomi- nalism, soul and body, mind and matter. But they will con- tain all that can be observed. Even the inexplicable facts left [56] THE SCIENCE OF MAN out by classical conceptions of man, those facts that stub- bornly refuse to enter the frame of conventional thought, and therefore may lead to unknown realms. Thus, our in- ventory will include all actual and potential activities of the human being. In this manner we shall become initiated into a knowledge of ourselves, which is only descriptive and still not far from the concréte. Such knowledge does not claim definitiveness or infallibility. It is empirical, approximative, commonplace, and incomplete. But also scientific and intelligible to every- body. [57] Chapter III BODY AND PHYSIOLOGICAL ACTIVITIES 1. Man. His dual aspect. Human activities and their substratum. 2. The dimensions of the body. Its form. 3. Its outer and inner surfaces. 4. Its constitution. Cells and their societies. Their struc- ture. Cell types. 5. Blood and organic medium. 6. Nutrition of tissues. Metabolism. 7. Circulatory apparatus, lungs, and kidneys. 8. Chemical relations of the body with its environment. Digestion. Nature of food. 9. Sexual functions. 10. Physical relations of the body with its environment. Voluntary nervous system. Skeletal and muscular systems. 11. Visceral nervous system. Sympathetic and parasympathetic. Automatism of the organs. 12. Complexity and simplicity of the body. Structural and functional limits of organs. Anatomical heterogeneity and physiological homogeneity. 13. Mode of organization of the body. Mechanical analogy. An- titheses and illusions. 14. Fragility and robustness of the body. Silence of the body during health. Factors which weaken the body. 15. The causes of disease. Infectious and degenerative diseases. I WE ARE conscious of existing, of possessing an activity of our own, a personality. We know that we are different from all other individuals. We believe that our will is free. We feel happy or unhappy. These intuitions constitute for each of us the ultimate reality. Our States of consciousness glide through time as a river through a valley. Like the river, we are both change and permanence. We are independent of our environment, much [58] BODY AND PHYSIOLOGICAL ACTIVITIES more so than are the other animals. Our intelligence has s& us free. Man is, above all, the inventor of tools, arms, and machines. With the aid of these inventions he was able to manifest his specific characteristics, and to distinguish him- self from all other living beings. He has expressed his inner tendencies in an objective manner by erecting Statues, temples, theaters, cathedrals, hospitals, universities, labora- tories, and factories. He has, in this way, Stamped the sur- face of the earth with the mark of his fundamental activities —that is, of his esthetic and religious feelings, his moral sense, his intelligence, and his scientific curiosity. This focus of mighty activities can be observed from within or from without. Seen from within, it shows to the lone observer, who is our self, his own thoughts, tendencies, desires, joys, and sorrows. Seen from without, it appears as the human body, our own, and also that of all our fellow creatures. Thus, man assumes two totally different aspects. For this reason, he has been looked upon as being made up of two parts, the body and the soul. However, no one has ever observed a soul without a body, or a body without a soul. Only the outer surface of our body is visible to us. We perceive our functional activities as a vague sense of well-being. But we are not conscious of any of our organs. The body obeys mechanisms entirely hidden from us. It dis- closes its constitution only through the techniques of anatomy and physiology. Then, a stupendous complexity appears under its seeming simplicity. Man never allows himself to be observed simultaneously in his outer and public aspect, and in his inner and private one. Even if we penetrate the inextricable maze of the brain and the nervous functions, nowhere do we meét with consciousness. Soul and body are [59] MAN, THE UNKNOWN creations of our méthods of observation. They are carved by those méthods from an indivisible whole. This whole consists of tissues, organic fluids, and con- sciousness. It extends simultaneously in space and in time. It fills the three dimensions of space, and that of time with its héterogeneous mass. However, it is not comprised fully within these four dimensions. For consciousness is located both within the cerebral matter and outside the physical continuum. The human being is too complex to be ap- prehended in his entiréty. We have to divide him into small parts by our méthods of observation. Technological necessity obliges us, therefore, to describe him as being composed of a corporal substratum and of various activities. And also to consider separately the temporal, adaptive, and individual aspects of these activities. At the same time we must avoid making the classical errors of reducing him to a body, or a consciousness, or an association of both, and of believing in the concréte existence of the parts abstracted from him by our mind. 2 The human body is placed, on the scale of magnitudes, halfway bétween the atom and the Star. According to the size of the objects selected for comparison, it appears either large or small. Its length is equivalent to that of two hundred thousand tissue cells, or of two millions of ordinary microbes, or of two billions of albumin molecules, placed end to end. Man is gigantic in comparison with an electron, an atom, a molecule, or a microbe. But, when compared with a moun- tain, or with the earth, he is tiny. More than four thousand [60] BODY AND PHYSIOLOGICAL ACTIVITIES individuals would have to stand one upon the other in order to equal the height of Mount Everest. A terrestrial meridian is approximately equivalent to twenty millions of them placed end to end. Light, as is well known, travels about one hun- dred and fifty million times the length of our body in one second. The interstellar distances are such that they have to be measured in light years. Our stature, in relation to such a system of reference, becomes inconceivably small. For this reason, Eddington and Jeans, in their books of popular astronomy, always succeed in impressing their readers with the complete insignificance of man in the universe. In reality, our spatial greatness or smallness is without importance. For what is specific of man has no physical dimensions. The meaning of our presence in this world assuredly does not depend upon our size. Our Stature seems to be appropriate to the character of the tissue cells, and to the nature of the chemical exchanges, or metabolism, of the organism. As nerve impulses propagate in everybody at the same speed, men of a very much larger frame than ours would have too slow a perception of external things, and their muscular reactions would be too sluggish. At the same time the rate of their chemical exchanges would be profoundly modified. It is well known that the metabolism of large animals is lower than that of small ones. The horse, for instance, has a lesser métabolic activity than the mouse. A great increase in our stature would diminish the intensity of our exchanges. And probably deprive us of our agility and of the rapidity of our perceptions. Such an accident will not happen, because the size of human beings varies only within narrow limits. The dimensions of our body are détermined simultaneously by heredity and developmental conditions. [61] MAN, THE UNKNOWN In a given race, one observes tall and short individuals. These differences in the length of the skeléton come from the state of the endocrine glands and from the correlation of their activities in space and time. They are of profound significance. It is possible, by means of proper diét and mode of living, to augment or diminish the stature of the individ- uals composing a nation. Likewise, to modify the quality of their tissues and probably also of their mind. We must not blindly change the dimensions of the human body in order to give it more beauty and muscular strength. In fact, seem- ingly unimportant alterations of our size and form could cause profound modifications of our physiological and mental activities. There is no advantage in increasing man’s Stature by artificial means. Alertness, endurance, and audac- ity do not grow with the volume of the body. Men of genius are not tall. Mussolini is of medium size, and Napoleon was short. Each man is characterized by his figure, his way of carrying himself, the aspect of his face. Our outward form expresses the qualities, the powers, of our body and our mind. In a given race, it varies according to the mode of life of the in- dividuals. The man of the Renaissance, whose life was a constant fight, who was exposed continuously to dangers and to inclemencies, who was capable of as great an enthusiasm for the discoveries of Galileo as for the masterpieces of Leonardo da Vinci or Michelangelo, did not resemble mod- ern man who lives in a steam-heated apartment, an air- conditioned office, a closed car, who contemplates absurd films, listens to his radio, and plays golf and bridge. Each epoch puts its seal on human beings. We begin to observe the new types created by motor-cars, cinemas, and athletics. [62 ] BODY AND PHYSIOLOGICAL ACTIVITIES Some, more frequent in Latin countries, are characterized by an adipose aspect, flabby tissues, discolored skin, protruding abdomen, thin legs, awkward posture, unintelligent and brutal face. Others appear, especially among Anglo-Saxons, and show broad shoulders, narrow waist, and birdlike cranium. Our form is molded by our physiological habits, and even by our usual thoughts. Its characteristics are partly due to the muscles running under the skin or along the bones. ‘The size of these muscles depends on the exercise to which they are submitted. ‘The beauty of the body comes from the harmonious development of the muscles and the skeléton. It reached the height of perfection at the epoch of Pericles, in the Greek athlétes whom Phidias and his disciples immortalized in their statues. The shape of the face, the mouth, the cheeks, the eyelids, and the lines of the visage are détermined by the habitual condition of the flat muscles, which move in the adipose tissue underlying the skin. And the state of these muscles depends on that of our mind. In- deed, each individual can give his face the expression that he chooses. But he does not keep such a mask permanently. Unwittingly, our visage progressively models itself upon our States of consciousness. With the advance of age it becomes more and more pregnant with the feelings, the appéetites, and the aspirations of the whole being. ‘The beauty of youth comes from the natural harmony of the lineaments of the human face. That, so rare, of an old man, from his soul. The visage expresses still deeper things than the hidden activities of consciousness. In this open book one can read not only the vices, the virtues, the intelligence, the stupidity, the feelings, the most carefully concealed habits, of an in- dividual, but also the constitution of his body, and his ten- [63] MAN, THE UNKNOWN dencies to organic and mental diseases. In fact, the aspect of bones, muscles, fat, skin, and hair depends on the nutrition of tissues. And the nutrition of tissues is regulated by the composition of blood plasma, that is, by the activity of the glandular and digestive systems. The state of the organs is revealed by the aspect of the body. The surface of the skin reflects the functional conditions of the endocrine glands, the stomach, the intestines, and the nervous system. It points out the morbid tendencies of the individual. In fact, people who belong to different morphological classes—for instance, to the cerebral, digestive, muscular, or respiratory types— are not liable to the same organic or mental diseases. ‘There are great functional disparities bétween tall and spare men, and broad and short ones. The tall type, either asthenic or athlétic, is predisposed to tuberculosis and to dementia precox. The short, pycnic type, to cyclic mania, diabétes, rheumatism, and gout. In the diagnosis and prognosis of diseases, ancient physicians, quite rightly, attributed great importance to temperament, idiosyncrasies, and diatheses. Each man bears on his face the description of his body and his soul. 3 The skin, which covers the outer surface of the body, is impermeable to water and to gases. It does not allow the microbes living on its surface to enter the organism. It is capable of destroying them with the aid of substances secréted by its glands. But it can be crossed by the minute and deadly beings, which we call viruses. Its external face is exposed to light, wind, humidity, dryness. heat, and cold. Its internal [64] BODY AND PHYSIOLOGICAL ACTIVITIES face is in contact with an aquatic world, warm and deprived of light, where cells live like marine animals. Despite its thinness, the skin effectively protects the organic fluids against the unceasing variations of cosmic surroundings. It is moist, supple, extensible, elastic, durable. Its durability is due to its mode of constitution, to its several layers of cells, which slowly and endlessly multiply. These cells die while remaining united to one another like the slates of a roof— like slates ceaselessly blown away by the wind and continually replaced by new slates. The skin, nevertheless, retains its moistness and suppleness, because small glands secréte on its surface both water and fatty substances. At the nostrils, mouth, anus, uréthra, and vagina, it joins the mucosas, those membranes that cover the inner surface of the body. All its orifices, with the exception of the nostrils, are closed by elastic and contractile rings, the sphincters. ‘Thus, it is the almost perfectly fortified frontier of a closed world. Through its outer surface, the body enters into communi- cation with all the things of the cosmic universe. In fact, the skin is the dwelling-place of an immense quantity of small receptor organs, each of which registers, according to its own Structure, the changes taking place in the environment. Tactile corpuscles scattered all over its surface are sensitive to pressure, to pain, to heat, or to cold. Those situated in the mucosa of the tongue are affected by certain qualities of food, and also by temperature. Air vibrations act on the ex- tremely complex apparatus of the internal ear by the me- dium of the tympanic membrane and the bones of the mid- dle ear. The nétwork of olfactory nerves, which extends into the nasal mucous membrane, is sensitive to odors. A strange phenomenon occurs in the embryo. The brain causes a part of [65 ] MAN, THE UNKNOWN itself, the optic nerve and the rétina, to shoot out toward the surface of the body. The part of the skin overlying the young rétina undergoes an astonishing modification. It becomes