The Biologist Speaks of Death


I TRIED during the war to tell the American people — so far, at least, as they might be reached through the Atlantic Monthly — something of the nature of the German arguments from biology why there must always be war, why there ought to be war, and even why Germany should win in the war then being waged. For I believed that Americans should know something of this feeling and attitude of the German people, or of a considerable, and certainly very influential, part of them. I do not wish to repeat too much of what I have already presented in Atlantic articles. But we need, for the purposes of our present discussion, to recall the essential features of this claim; for this argument from biology of the inevitableness, and even the desirability, of war has been used, and is used to-day, by others than Germans. Indeed, if the German people to-day admit the argument with all of its implications, the result of the war should be accepted by them as a revelation and proof of their evolutionary biological unfitness in comparison with nearly a score of other peoples; and the Germans should not care to recall the argument. But I have heard of no statement from German sources to this effect.

The argument to which I have referred is based on the assumption that natural selection is the all-powerful factor, almost the sole really important factor, in organic evolution. And that, as man as an animal species is subject to the control of the same major evolutionary factors which control the other animal kinds, his evolutionary progress, or fate, is to be decided on the basis of a rigid, relentless natural selection. It is the argument from a post-Darwinian point of view, of which Weismann, an eminent German biologist, was chief exponent, and which goes much beyond Darwin’s own conceptions.

Natural selection itself, as you know, is the outcome of a bitter and persistent struggle for existence, in which struggle the fittest, or fitter, survive, while the less fit become either much modified or extinguished. This struggle has three chief phases.

1. An inter-species struggle, or the lethal competition among different animal kinds for food, space, and opportunity to increase.

2. An intra-species struggle, or lethal competition among the individuals of a single species, resultant on the overproduction of individuals due to natural multiplication by geometric progression. And

3. The constant struggle of individuals and species against the rigors of climate and the danger of storm, flood, drought, cold, and heat.

Now any animal kind and its individuals may be continually exposed to all these phases of the struggle for existence, or, on the other hand, any one or more of these phases may be largely ameliorated, or even abolished, for a given species and its individuals. This amelioration may come about through a happy accident of time or place, or because of the adoption by the species of a habit or mode of life that continually protects it from a certain phase of the struggle.

For example, the adoption by two widely distinct, and perhaps originally antagonistic, species of a commensal or symbiotic life, based on the mutualaid principle, — thousands of such cases are familiar to naturalists, — would ameliorate or abolish the inter-specific struggle between these two species. Even more effective in the modification of the influence due to a bitter struggle for existence, is the adoption by a species of a social or communistic mode of existence, so far as its own individuals are concerned.

As a matter of fact, this reliance by animal kinds, for success in the world, upon a more or less extreme adoption of the mutual-aid principle, as contrasted with the mutual-fight principle, is much more widely spread among t he lower animals than is familiarly recognized; while in the case of man, it has been, in connection with high brain-development and the acquirement of the power of speaking and writing, the greatest single factor in the achievement of his proud biological position as king of living creatures.

Altruism — or mutual aid, as the biologists prefer to call it, to escape the implication of assuming too much consciousness in it — is just as truly a fundamental biologic factor of evolution as is the cruel, strictly self-regarding, exterminating kind of struggle for existence with which the Neo-Darwinists try to fill our eyes and ears, to the exclusion of the recognition of all other factors.

This mutual aid, as a biologic or natural factor, has influenced materially, as I have said, the mode of life, the biologic success, and the character of the evolution of many kinds of lower animals. In their case, it was not, we presume, consciously chosen or consciously developed. In the case of man, however, where also mutual aid has been a fundamental factor in determining the mode of life and the success and character of the evolution of the species, and where in the beginning also it may have been entirely unconsciously taken on, we face an important new thing in relation to it: that is, its conscious development. Indeed, it is the high development of mutual aid, plus a high degree of brain-power, plus the existence of something we call spirit or soul in man, all of these interacting on each other to the advantage of the further development of each, that really distinguishes man from other animals, and makes him human. This conscious development of mutual aid, or altruism, byman demands some further consideration of the problem of war as the biologist faces it.

Man differs markedly from other animal species in having two kinds of inheritance, often confused because of the use of the common term, inheritance, for both kinds. He has a biological inheritance — this is real heredity, inherent in him, and responsible for much of his physical and mental condition, and for that reflex and instinctive behavior, partly indispensable for the actual maintenance of his life and health, but partly no longer indispensable, in his present stage of evolution, as in the cases of various brute performances once necessary to his self-preservation.

He has also a social inheritance, not a part of his heredity, but playing a very important and conspicuous rôle in his life, especially in his less material, his higher life, as we are accustomed to call it — the part of his life that especially characterizes him, and makes especially worth while being human. Man is not born with this social inheritance in him, as his biological inheritance is in him, but with it all about him, ready for him and certain to be, in some measure, imposed on him. He is born into it rather than with it in him.

This social inheritance consists of tradition, of recorded history, of precept and example — of education, in a word. It is possible because of mutual aid, and speech, writing, and printing. Other animals, especially a few of the higher ones, may also enjoy a certain social inheritance; but man’s social inheritance is so incomparably greater and more important in determining the character of his life, that he is in this respect qualitatively different from all other animals.


Now, with all this in his eyes, the biologist interested in the problem of the inevitability of war and the desirability of it sees the situation as reducible to rather simple terms. If man prefers, or surrenders himself, to be ruled in his relation to fighting and war by his biological inheritance, then war will persist. Or if he decides that the best way to develop the highest type of man and human culture is to depend primarily on the natural selection based on a ruthless, physical, life-or-death determining struggle for existence, with a survival and dominance of the materially strongest, then war is desirable.

But if he recognizes that he must take into account, in his study of human development, another evolution factor, not less natural, and of proved effectiveness, which is based on the mutual-aid principle instead of the mutual-murder principle, and one which can be backed by all the force of social inheritance to counteract certain opposing influences of biological inheritance, then war need be to him neither inevitable nor desirable.

The protagonists of inevitable war declare that human nature does not change. The biologist declares that human nature does change, both by virtue of the influences of strictly biological factors, and especially by virtue of the influences of social inheritance. Human nature to-day, which is certainly not the same as human nature in early Glacial time, is quite as much the resultant of the work of social-inheritance factors as it is of factors of biological inheritance. Human nature — not just the part that is inherited, but the whole of it, including the part that is acquired by each generation — not only changes, but can be made to change in definite direction by education; and it can be made to change with reasonable rapidity—a rapidity that seems very rapid indeed to the biologist accustomed to see change mostly depend on slowly modified heredity.

Let us turn now to one or two more of those problems which especially involve in their consideration this matter, introduced by our reference to the warproblem, of the two kinds of inheritance and the relations between them.

The problems that I have especially in mind at this moment introduce conspicuously the subject of human heredity. Is a man what he is because he is born so, or because he becomes so by education, using education in the broad sense of including all environment?

With the work and theories of Mendel and the three botanists, Tschermak, Correns, and DeVries, as stimulus and basis, there has been an energetic pushing on of heredity studies, with a rapid gaining of many facts and much understanding, until now we are able confidently to make statements about the heredity mechanism and behavior that are really startling in their preciseness and practical importance. We can make enough prophecies about the outcome of many cases of mating, to give us sufficient basis to warrant us in modifying our social inheritance in directions intended to increase advantages or decrease disadvantages derived from biological inheritance. Not all traits are inherited according to the Mendelian order, but many are. This order can be found out if it exists, and then from it can be predicted the outcome of certain matings.

It must be found out by experiment (in lower animals and plants), or observation (in human beings), for each specific trait in each species of plant and animal, and for man. It will take a long time to work out the order of heredity for all the Mendelizing traits, physical and mental, which the human species possesses; but it can be done; and then we can bring to bear the power of our social inheritance, to make human life rapidly better by encouraging the good and discouraging the bad in biological inheritance.

But we do not have to wait until we know the order of inheritance for all our traits before we can begin to use wisely this new knowledge of heredity, which began with the revelations of the Augustinian monk Mendel, about the inheritance of stem-length and pod-shape and seed-coat of garden peas. We can begin on a basis of the knowledge of the heredity behavior of a single trait. Let me give an example.

For a long time the characters considered in studies of heredity were exclusively physical ones. Just as in the beginning days of anatomical study man’s body was considered too sacred to be submitted to dissection, so in the beginning days of heredity study man’s mental traits were considered too sacred for scientific analysis. But ever since Galton, students of human heredity have paid attention to the inheritance of mental traits and general mental capacity. It is a fascinating thing to trace the descent of genius or great talent through the succeeding generations of a family. The Bach family contributed an extraordinary number of notable musicians to the world, in several generations. But, if mental capacity is inherited, so is mental incapacity. It has been fairly satisfactorily proved that the mental condition of feeble-mindedness not only is an inherited condition, but may be looked on as a unit human trait, following the general Mendelian order as to its mode of inheritance. If this is really so, — and it is hardly any longer open to doubt, — it has obviously a most important significance in connection with the whole problem of education. It must make us face squarely the situation that there are limits to the educability of certain individuals, and that we should somewhere call a halt on our vain efforts to put the same kind and amount of education into all kinds of pupils.

This fact of the heritability of feeblemindedness has also an important significance in connection with a particular social problem — that of juvenile delinquency; for it has been proved beyond much doubt, by the studies of Goddard, Davenport, Kuhlmann, Williams, and others, that feeble-mindedness and delinquency are all too often closely linked in terms of cause and effect.


Now these three matters of war and juvenile delinquency and racial wellbeing are but three examples of the many problems of human life having obvious and fundamental biological aspects. But how little has the world, although intensely interested in these problems and anxiously trying to solve them, taken any advantage of the special knowledge offered by the biologist in connection with them. And this despite the fact that it has been in recent years quite the fashion to invite the biologist to talk about such problems, and even to listen to him with a tolerant interest. But why this fashion of listening to his advice, and at the same time the fashion of not acting on it? Well, it is not all the fault of the public: it is partly the fault of the biologist.

In the first place, the biologist seems unable to escape from the use of a terminology that is to be found only in the larger dictionaries — and these dictionaries are at home, while the public is in the lecture-hall. There are hundreds of interesting and pertinent facts of biology that are to-day awaiting intelligible telling in order to be made use of!

In the second place, the biologist apparently has difficulty in estimating the varying degrees of practicalness of his knowledge. Take the very examples I have used in this paper. If the biologist has nothing more to contribute to the discussion of the tremendously important and pressing problem of war than the assurance that human evolution will carry us beyond war in another geologic epoch or two, he may be listened to with tolerant interest, but he will start nothing to help put an end to war.

Of course, I think that he really has more to offer. I have even tried to indicate what it is that he can suggest, namely, to fight the false notion that human evolution must be left to natural selection, and that war produces natural selection; as a matter of fact, war produces artificial selection more than natural selection, and a bad or reversed artificial selection at that. He can also encourage the right notion that a certain biological inheritance, especially that already vestigial, can be largely offset by social inheritance. In fact, it is social evolution, not biological evolution, that we must chiefly look to for future human progress. Most anthropologists agree that the major difference between present man and primitive man — not man of the early Ice Age, but primitive man of late pre-historic times — lies less in physical differences and mental capacity, than in the possession by present man of methods and technique based on scientific knowledge not possessed by primitive man; that the difference is chiefly one of social inheritance, and modern man has gained over primitive man in this regard with ever-increasing acceleration. His movement of advance has been like that of a snowball, rolling faster as it gets bigger. Many biologists believe that man is already so specialized an end-product of his evolutionary line, that, as regards physical change and actual mental capacity, he has reached the standing-still stage. Certainly man to-day, as individual, is not to be regarded as superior to man of early historic times, of the times of Greek greatness, or, probably, even of the times of early Egypt and Asia Minor.

In connection with the matter of juvenile delinquency and racial well-being the biologist’s contribution of facts and suggestions is of tangible practicability. The biologist says that the normal man who married a feeble-minded woman and started a line of descendants of whom four out of five were socially incompetent, and hence burdens and dangers to society, and who then married a normal woman and started another line of descendants, all socially competent, should have been prevented from making the first mating. Don’t call this eugenics — call it an application of scientific knowledge and common sense. Think of it as just as important and just as possible as the enforced isolation of a victim of infectious disease, or of homicidal mania.

But not all the problems of human life, in the discussion of which the biologist ventures to take part, exhibit their biological aspects so clearly as the examples thus far referred to. The approach of the biologist to these other problems, even his right to approach them, becomes more debatable - but, for that very reason, perhaps, more interesting. Can the biologist, with his methods of analysis and his knowledge of other kinds of life than human life, make any, even least, contribution to those things which most of us demand first from existence, namely, personal achievement, personal service to humanity, personal happiness? Can he show us wiser ways of living? He can unquestionably show us safer ways; and presumably for that reason alone it is quite worth our while to call on him to give us the benefit of his special knowledge and his reasoned recommendations. But merely being safer amid danger is not what many, very many of us, are chiefly concerned with. We want continuing to live to mean something continually larger. Has the biologist anything helpful to suggest about this? Or will listening to him mean more pessimism, hopelessness, fatalism? If so, perhaps we would prefer to be blindly hopeful, ignorantly happy.


I can understand, although I do not share, a certain feeling of repugnance to accepting the situation forced on us by scientific fact and logical induction. I can sympathize with, although I do not accept, the position of those who persist in wishing and trying to look on themselves and human kind in general as of a different clay, endowed with a different breath, and existing in a different sphere from the rest of life. I can feel the egocentric urge that leads to this position perhaps as strongly as those who take it, but I cannot surrender to it as easily. Scientific observation and cool reason prevent. How can one accept eagerly and gratefully that knowledge about our bodily makeup and functioning which t he biologist gives us, and, on the basis of it, proceed to modify our behavior so as to protect ourselves from accident and disease, and help ourselves in the attempt to adapt ourselves to the actual conditions of the world we live in, and yet reject other no less well-demonstrated facts of the same general category, brought to us by the same biologist, but the acceptance of which involves the recognition on our part of our true place in Nature.

I am inclined to find an explanation for this popular inconsistency in two or three different causes. For one thing, some biologists have gone ahead of the actual facts with their justifiable significance, and have presented the world with hypotheses instead of demonstrations, and have insisted on an acceptance of unjustifiable significance. For another thing, one can never get away from letting one’s own observations, with all their limitations as to both scope and accuracy, play a too large part in determining one’s judgments about any matter, however technical, and however demanding, for correct understanding, a certain special training and equipment on the part of the observer. This is one of the reasons why the professors of political economy and sociology have such a hard row to hoe. Everyone is his own economist and sociologist, because the subjects are, perforce, under everyone’s observation, although this observation may really be very limited, and usually is of a most untrained and unmethodical kind. Professors of astronomy, on the other hand, are accepted unhesitatingly as authorities — so few of us have telescopes.

Now the biologists have a position between these extremes. When they talk about microbes and dinosaurs, their statements are accepted at facevalue. But when they talk about human beings, whom they can study quite as carefully as they can other kinds of beings, there are reservations. When the biologists’ talk about human beings is limited to statements about lungs and liver, skeleton and ductless glands, it is not questioned. But when their talk is about the behavior of human beings, about their psychology, their heredity, their responses to environment and education, and their position in nature, then it is tested by the miscellaneous personal observations and prejudices and desires and hopes and beliefs of each individual, and it is accepted or not as it confirms or contradicts each one’s notions derived from these things. We all, or most of us, think we know human beings as well as the biologist does. Most assuredly the biologist does not know ail that is to be known about human beings; and about that which he does not know we must certainly be permitted to accept our own guess as likely to be as good as his. But we are too likely to think our own guess even better than his.

This latter attitude comes largely, I think, from a feeling, after hearing the biologist talk about human life, that his consideration of this life is too academic, too technical, too detached from most of those things that make up our immediate interests and fill our present moments. The matters that occupy our principal attention arc our work and recreation, our clothes and food, our household affairs, our health and our looks, our income, expenditures, and savings, the growing-up of our children and the growing old of ourselves, our family and social relations, our personal contacts with people, and our opinions of them. We think and talk about books and music and pictures, about railways and bridges and motorcars, about scenery and climate and hotels, about politics and diplomacy and governments. And all the time we give a fascinated attention to the particular human beings connected with these things, especially the ones we personally know or see. We note and discuss their particular idiosyncracies, their likenesses and differences; we compare them with each other and with ourselves. We are concerned, constantly and immensely, with individuals.

It is right at this point, I believe, that we have a clue to the explanation of the gulf between the biologist-student of human life and the everyday observer of human life. One deals primarily with the species, the other with individuals. One gives his attention to human-kind, the other to particular human creatures. If we knew other kinds of animals as individuals, — and we do occasionally, as when we have a particular horse or dog or cat or canary for companion, or scrape literary acquaintance with Lobo the Wolf, or Bre’r Rabbit; I have even come to know individual bees in my glass-sided observation hives, — if we knew other animals as individuals, I say, we should have another point of view regarding them. But, as species, they do not interest many of us very much; although it is exactly as such that they do interest the biologist. And it is primarily as species that the biologist is interested in human-kind. That is why the biologist’s information to us about man leaves us cold. And why the daily newspaper’s information about men fascinates and thrills us. And yet — and yet — the biologist’s information, so far as he can confidently go with it, is of huge importance to us as individuals. Taken into account and acted on, it can make wiser, less wasteful, more capable, happier individuals of us. And it need not rob us of the hopes and beliefs that many of us cherish. It may do nothing to encourage them, but it cannot, certainly at present, make us give them up. And I do not think it ever will.


I have had, during the very writing of this paper, the distressing experience of being brought, suddenly and dramatically, to face that problem of human life which to most of us is the greatest of all its problems — I mean the problem of death. One evening, on a train from Chicago to Washington, returning with a companion from a week’s association with hundreds of other scientific men, I spent the hours between dinner and bed-time discussing with my companion the possibilities of science in helping us to understand Nature and Life. He was a man who had given thirty years, with all the advantage of great ability and highly perfected training, to scientific study. He was withal a most attractive and lovable personality. We parted at the evening’s end with smiles of friendship and mutual encouragement to push on with the task that we had in common. In the morning I found him dead in his berth.

What does the biologist have to tell us of death? Well, first, true to his professional interest, he tells us of the facts and the significance of the death of species. Death of species is at once the revelation and the proof of the struggle for existence, with the consequent survival of the fit. Dead species have been the stepping-stones to new species; their history is the history of organic evolution. Species are unfit, or become unfit, for various reasons; among them, the reason of over-specialization. This is rather surprising, for all organic evolution is a movement from generalization toward specialization; yet, in the very acquirement of this specialization are sown the seeds of speciesdeath. What organisms gain in specialization they lose in plasticity. They become so adapted that they lose adaptability. Progress in one direction involves, as someone has said, the closing of the gates in countless other directions; progression thus means a succession of lost opportunities. The Irish stag, specializing in antlers, was brought by too large antlers to species-death. The great dinosaurs, lords of their epoch, extinguished themselves by too much muchness. There are even analogies of these biologic happenings in human history. And there are even biologists who see the triumphantly superspecialized species, man, in actual danger of species-death from too much specialization.

But one of the major lines of human specialization is what might be called a specialization in the direction of safety from over-specialization; it is a specialization in general adaptability, not in particular adaptation. Man has become able to follow varying natural conditions. Man’s narrow biologic specialization — think of the narrow limits of temperature, oxygen, food, and other conditions, in relation to his mere maintenance of life — is offset by his wide social inheritance and his educability. This gives him the power to withstand and dominate antagonistic nature — even the power to add the forces of nature to his own forces. He fights against natural selection; he substitutes a purposeful artificial selection for it. His possession of consciousness, reason and volition, by which he makes effective a scientific method or technique of successful struggle with nature, seems to insure him against species-death, at any rate in any geologically near future. Cataclysmic world-change would wipe him out easily, so specific is his biological adaptation to present conditions; but slow change — and that seems the geologic rule — finds him well protected, so developed is his power of conscious adaptability and his partial control of the conditions of life. ‘What a plastic little creature man is!’ said Emerson. ‘So shifty, so adaptive! His body a chest of tools, and he making himself comfortable in every climate, in every condition.’

But it is not human species-death but human individual-death that most of us look on as the problem of death. It is here, as always, in individuals, including our individual selves, not in species, that most of us are principally interested. What has the biologist to say about this kind of death?

Truly, very little. To explain to us that the human body is a machine that differs from other machines with which it may be compared in that, when it is once stopped, it cannot be set going again, is not in the least to solve for most of us the great problem. Is death really just what it seems, and what the biologist describes it to be, or is it what so many would like it to be, hope it is, and even firmly believe it is? Can the human individual have an ethereal spirit existence apart from, or after, his bodily-machine existence? Is man immortal? That is what we insist upon asking the biologist, who assumes a knowledge beyond that of most of us concerning human life.

The biologist, unless he is a scientific bigot, confesses at once the limitations of his knowledge. He does not claim that his description of individual death necessarily tells the whole story. But he claims that it tells it so far as the kind of evidence which he can accept as telling him things he can rely on now permits. Just because a single part in the complex material machine, or association of engines, that was my friend’s body, suddenly breaks down, is that the end of his story? One evening, all that nature and man had done for him were available for our good and his happiness. The next morning, because a trivial mechanical disharmony prevailed during the night over what had been for fifty years mechanical harmony, he is nothing more to us or himself. This seems preposterous, incredible. Must we accept it, biologist?

Sadly he answers, 1I can give you no comfort. That same waste of Nature’s efforts — if it really is waste — is apparent all through the realm of life. This unconscious waste of Nature is no less preposterous, incredible to me,’ he says, ‘than that every now and then, consciously flying in the face of what seems to be all self-interest, all enjoyment of life, all reason, millions of men swarm out of their homes, to use all their energy, all their native cunning, all their hard-won scientific knowledge, to kill each other, to bring intense suffering to their wives and children, to destroy their accumulated material possessions, to burn the created glories of their artist geniuses, to work, in a word, all the waste and misery that are the inevitable accompaniments of war. Is this less incredible,’ he asks, ‘than that Nature should tolerate the extinguishing, after a period of functioning, of the complex of elaborately built-up machines which is the human body?’ And he adds that the same extinguishing comes to every other animal machine, to all other living bodies. Do you ask for something to continue after death of the pet dog, the favorite riding-horse, the bird you shoot as game, or the insect you crush under your feet? ‘ I find no proof, scientific proof,’ he says, ‘that death is not the end of these creatures. And you do not ask me to believe otherwise because of any desire or belief on your part that death is not their end. Well, no more do I find any proof, of the kind I am familiar with and content to accept, that death is not the end of man. I do not say that death is the end, that I have scientific proof that it really is the end; but I have no proof, yet, that it is not the end. The strong desire and hope, and that next conscious state, belief, which you suggest to me as proof to you that death does not end all, are not the kind of proof on the basis of which I ask you to accept what I do really feel able to tell you as facts about human life, facts many of which you are inclined to accept on my word.

‘Nor have I been able to find proof — the kind of proof that proves things to me — of immortality, by attending spiritist séances, or by reading the volumes of the Society for Psychical Research, or the many other books that recite the experiences of alleged participators in, or observers of, things of after death. I should, indeed, truly be appalled by death,’ the biologist says, ‘ and it would have a terror for me greater than it has even as a possible complete extinguisher of my personality, if it meant that it was the beginning for me of a perpetual personal spirit-existence, in which my thoughts and conversations were to be of the kind exam pled by those recorded in the Psychical Research and spiritist books. I do not wish t o spend a spirit-existence responding to calls from earth to describe the quality of the cigars that I am permitted to enjoy in my eternal life beyond.’

But in the same breath the biologist says, if he is not a bigoted biologist, that he has no right to say, and will not say, that there cannot be a human spirit-life.

He cannot authoritatively, and hence will not try to, affirm that there cannot be human immortality. He simply remains agnostic. He does not know.


Then there is the cognate matter of soul in the living body. The biologist sometimes has a difficult time trying to understand what other people understand by soul. If sweetness of disposition or amiability of character is a symptom of soul, as he is told by some, then he finds soul in many animals. I had two tarantulas once in my laboratory, one of whom was an ugly-tempered morose brute, who, whenever I approached him with playful finger, became angry and, rearing on his hinder two pairs of legs and unfolding his great poisonfangs, made ready to lunge and strike whenever his malicious intelligence assured him that he could reach and wound me. But the other tarantula, of the same kind and found in the same field, would let me fondle him and would walk in friendly fashion up my bare arm, without ever a thought of hurting me. He was a sweetly dispositioned tarantula.

If you say that I should not attribute character or disposition to these spiders, but should limit myself to describing their manner of behavior, because we do not know that their behavior was controlled by their disposition, — chemical or physical stimuli may have controlled it, — then I reply that I can quite as easily and much more confidently describe the similarly contrasting behavior of two human individuals in terms that we usually limit ourselves to in describing animal behavior. The difference is, we have had so much experience with human individuals, that is, have made so many observations and so many experiments on them, that, in our search for the springs of this behavior, we have become accustomed to saying that such and such behavior indicates such and such kind of disposition, a large or small possession of kindliness, or, as some might interpret it, soul. If we knew tarantulas better, we might be able to use the same generalization, and discriminate among them as fairly.

Mother-love reveals the human soul, says one; but mother-love is a commonplace among the higher animals and some of the less high. Love and sacrifice of self for family and community prove soul: well, the worker bee works till it falls dead on the threshold of the hive, with honey-sac or pollen baskets filled with food, which it is bringing home to feed the babies and queen and drones of the hive. Faith in an all-wise and all-kind God proves the soul in us. The primitive Africans have no less faith, although their God is made of wood or mud. John Muir’s dog, Stickeen, seems to have had no less faith in his master, at whose insistence he leaped the dangerous glacier crevasse that seemed too wide. Had Stickeen a soul?

But other people mean other things by soul: they mean the creative imagination, the capacity for self-expression of the wonderful things in them. Yet a simple physical injury or disharmony in these material body-tissues means a prompt end to all these wonders. A boy companion of mine was called, because of what he could do in music, a genius. He fell one day from a gate-post and struck his head against a stone. In a few weeks he was as strong a boy as he had been before, but he was no longer a genius. There was no longer any soul in his music. Was it his soul that struck the stone? Soul seems to mean, or at least to require, continuing mental balance.

The brain is a wonderful instrument in some human beings; in others, whole communities or tribes of others, it now enables its possessors to count no more than five. Trained human reason does wonders; so does the untrained instinct of the social wasps and the fungusfarming ants. The Brooklyn Bridge is a triumph of engineering; so is the orbweb of the garden spider. I do not mean that there is no difference between the brain of man, on which seems to depend a part at least of his soul, and the cephalic ganglion of the ant. But may not this difference be one of mass and histologic differentiation and organization, rather than of fundamental kind or quality; may it not be quantitative rather than qualitative? For all practical purposes, this difference may be such as to make two very different sorts of creatures out of men and ants; but is one to be assumed to be fundamentally foreign to the other? so fundamentally foreign that one means soul and immortality and the other only carnality and clay? Perhaps it is: I do not know.

Much that means soul and human attributes assumed to be peculiarly and fundamentally derived from somesource other than one common to other forms of life, has been plausibly shown by biologists and sociologists to be a highly developed derivative of more animallike attributes. Love may be a beautiful outgrowth from the animal necessities of reproduction and protection; charity, from the requirements of an advantageous development and exercise of altruism in the case of an animal species that has adopted the mutual-aid principle in evolution rather than the mutual-fight principle; hope and belief may be the by-products of a brain-development that has outrun utility, even as the Irish stag’s antlers out ran advantage in size.

Emotion itself is a great problem. There are fundamental emotions or conscious states, such as fear and hunger and sex-interest, which are plainly closely related to the animal part of our life; and other less fundamental, or derived, emotions, such as desire, hope, and confidence leading to belief, and doubt and depression leading to despondency, which are apparently a product of our more intellectual life. But that is to say that they differ from the fundamental emotions common to other animals as well as ourselves only because of our more elaborate and superior nervous development. These derived emotions are among the particularly distinguishing attributes of human life as compared with animal life, and play a great part in all of our everyday living. We see more of them, are impressed more by them and think more about them, under ordinary circumstances, than we do about the more fundamental emotions; but how quickly and powerfully the fundamental emotions dominate us, under circumstances that strip off for the moment our veneer of social inheritance and of so-called peculiarly human qualities. The war revealed this vividly, although it also revealed how some individuals had arrived at a stage in human evolution which enabled them to dominate their brute-inheritance in a most wonderful and encouraging way.

An authorized lecturer, representing a certain organization with many adherents, stated in an address in Washington the other evening, that the world is a mental phenomenon, and hence that all the things we know in it are controllable by mind, or, indeed, are simply manifestations of mind. That rat her seems to put in the hands of each person possessing mentality the power to do things to, or with, this old world, and the conditions of life on it, much as he wills to do them.

I must confess that the biologist sees the world differently. He finds it composed of a lot of things, and sees going on, in and about it, a lot of things that are hard to reduce to mental phenomena and hard to make amenable to his desires and control.

In Stanford University a number of years ago, I used to walk through an avenue lined with trees — I believe they were trees — to the beautiful quadrangle of buildings, with a companion, now a distinguished professor of philosophy in an important Eastern university, who proved during our walk each morning, by what was to me a verbally irrefutable logical argument, that there were no trees along our way and no quadrangle before us. However, when, after successfully avoiding the treetrunks, we reached the quadrangle, we entered it quite naturally and unsurprised, and went on under its arcades to take up our duties in our respective classrooms in it. We, or rather the professor of philosophy, had simply had a pleasant after-breakfast exercise in mental gymnastics. I had done my gymnastics — other gymnastics — before breakfast.

The biologist is willing to bet his life that much of the world really exists in a material sense. If the philosopher and I were standing on a railway track, with a locomotive engine tearing toward us at fifty miles an hour, he might prove to me, if there was time, by his interesting play of words and logic, that nothing was there, and hence nothing was going to happen if our non-existent bodies continued to stand still on the non-existent railway. But I should win my bet that something very distressing would happen, unless we stepped off the track, and that pretty quickly.

The biologist is a homely and practical-minded person, who is little given to over-refined logic and debate, but much given to observation and experiment. His laboratory tells him what a precarious and fragile thing life is, how material and condition-ruled and circumscribed a living creature is. But his wife and child and his own consciousness tell him how much more, how immeasurably more, there is in life than he learns in his laboratory. It is this extralaboratory observation and realization of the possibilities and actualities of human life that make it, even to the biologist, the vivid, many-colored, suggestive, and thrilling thing it is — the thing so full of occasionally realized great moments and of glimpses of infinitely great possibilities, that sometimes it seems all mystery, all something more than of this world, and hence all something quite hopeless to study by the methods of his science, indeed quite hopeless even profitably to wonder about. Why not take it and make the most of it?

And then comes the insistent question: Ah, how make the most of it? And he becomes again the patient, struggling student of biology, the student of the laws or conditions of life.


The goal of the biologist — however unattainable, or most limitedly attainable, arrival at it may now seem to be — is to be able to speak with confidence of the future behavior or fate of living things; of living things as individuals and as groups and kinds. The biologist really aims at being able some time to speak confidently about the future and destiny of human-kind.

If the biologist finds himself quite unable to say much that is worth listening to about the future of human beings after death, he is at least ready to venture some suggestions about the future of the human species in its material relations to the world and world-conditions it lives in, and about the possibilities or probabilities of its further development or evolution.

This evolution is a fundamental element in life. Primarily, it simply means change; but history — geologic and biologic history — has shown that this change has been progressive; it is change forward and upward. What causes it, we do not know, despite our glimpse of some of its factors; what it really is, we do not know, despite our sight of its results. ‘Some call it Evolution, and others call it God,’ sings William Carruth. But it is real. Human life to-day is what it is, because of it; human life will be to-morrow what it will be, because of it. Is the biologist in a position to hazard prophecy as to the future course of human evolution?

As Conklin has pointed out, progressive evolution of special lines of animals and plants has limits fixed by its very nature. Now man has gone a long, long way in the progressive evolution of his body and its functions. But it is apparently true, that for ten thousand years there has been no notable progress in this evolution. If evolution is carrying man forward, — and we do not doubt it, — it is doing it in a different way. This way seems to be the way of social evolut ion, based on man’s social inheritance and the biologic factor of mutual aid. If so, we have to see man of the future as the possessor of an ever more elaborate and higher development of social inheritance, and more and more capable, by virtue of this social inheritance, of an inhibition of the vestigial brute carry-overs in his biological inheritance. That means, in the ultimate analysis, that future man can be consciously determined by man to-day; that human evolution has been turned over to human-kind itself to direct. What an opportunity, but, at the same time, what a responsibility!

Here is where the biologist becomes the preacher and exhorter. Here is where biology and the appeal to reason, where technical knowledge and common sense, where science and religion join. The soundest of science leads us to the conclusion that man, by virtue of the possession of a social inheritance, as contrasted with the biological inheritance which is all the inheritance that other animal species have,—a social inheritance which gives him the present realities and the future possibilities of a social evolution, in addition to his more personal evolution,—has in his own hands a great instrument for determining the fate of himself as species, the future of mankind. This, of course, is what the preacher and the poet have always said about man, though on a basis of other conceptions as to how man has been given this power. But whatever the foundations may be for the agreement between scientist and preacher in their common conclusion, the interesting and important thing is that they do agree, and hence that they can reinforce each other in appealing to man consciously to direct his efforts, with all his advantage of scientific knowledge and all his strength of belief, to the production of a higher — a socially and morally higher — future-man type.

Biology is not a science for its own sake alone. It is a science eminently useful and practical to man, and at the same time it is a science highly inspiring to him. For if it be depressing, as it may be to some, though it is not to me, in that it teaches him that man’s life is close brother to all the rest of life; yet it is inspiring, in that at the same time it reveals how wonderfully much has been done by Nature in making man, and how now man has been let into partnership with Nature for making better man.

We are not a foreign matter, or being, imposed on Nature, but Nature’s own proudest product. And the power we have for our further and higher development is not our own unaided power, but our own and Nature’s in combination. It is a combination that should have almost limitless possibilities.