A first book in organic evolution

Finally, in man (Plate XII), the whole brain has grown so enormously that it is three times larger than the brain of the highest simian creature. The cerebrum, especially, has increased enormously in size. It has grown not only backwards (overlapping cerebellum), upwards, and downwards on the sides, it has grown so far forwards as not only to cover the olfactory lobes, but also to project far beyond them. The cerebellum has also increased in size and complexity, especially the lateral lobes. The ideal vertical section (Fig. 23) shows diagrammatically in one figure all these stages in the evolution of the human brain through the geologic ages.

It is a very interesting and instructive fact that in the development of the human brain from the fertilized ovum these same stages, which are permanent conditions in the zoölogical (taxonomic) series, are passed through by it as transient stages.

One of the earliest conditions of the human brain is that in which it presents three swellings in a serial arrangement. They are known from behind, forwards as hindbrain, midbrain, and forebrain. For our purposes it is sufficiently accurate to say that the fœtal brain, in developing from this early condition to a later and higher condition, differentiates the hindbrain into the medulla (Fig. 24, m) and the cerebellum (cb); the midbrain becomes the optic lobes (ol); and the forebrain differentiates into the thalami (th) and the cerebrum (cr). A little later the cerebrum buds forth the olfactory lobes (of), so that the human brain will consist of six fundamental segments,—one behind the other. This is the fish stage in the growth of the human brain. (Compare Fig. 24 with Fig. 19.)

As development proceeds the most conspicuous growth of the brain is observed in connection with the cerebrum and cerebellum. The cerebrum particularly grows relatively and actually larger and larger, but does not yet cover any portion of the optic lobes. This is the reptile stage, represented in Fig. 25. The cerebrum, continuing to grow, finally covers the front portion of the optic lobes. This is the marsupial stage, and is shown in Figs. 26 and 27. Growing further, it soon covers a greater or less portion of the cerebellum. These are the prosimian (Lemur) and simian stages. Finally it grows so far backward as to completely cover the cerebellum, and so far forward as to project much beyond the olfactory lobes. This is the human stage (Plate XII).

In the study of the phylogeny of the brain we found that the cerebrum in fish, reptile, and lower marsupial is smooth. In the primitive primates (Lemuroidea) it is convoluted; in the simiidæ it is still more convoluted, while in man it reaches the climax of complexity in the size, number, and sinuosity of its convolutions. The object of these convolutions is to increase the surface of the cortex of the brain, the cortex being the seat of psychic phenomena. Other things being equal, the greater the amount of cortex the greater is the intelligence. During its embryonic development the human cerebrum passes also through the stage of smoothness to a convoluted condition; then through stages of increasing complexity of convolutions. Simultaneously with this advance of cerebral organization, there is an unfolding of increasing intelligence.

The cerebellum presides over the co-ordination of the muscular movements of the body. It also, like the cerebrum, passes through the fish, reptile, marsupial, lemur, and simian phases. At first it consists only of the median lobe; then the lateral lobes appear, at first small in size, but getting larger and larger until they greatly surpass in bulk the more primitive median portion. At first the cerebellum is smooth, but as it develops, its fissures become greater and greater, thus increasing its cortex, which presides over the muscular movements. With the developing cerebellum are associated increasing powers of muscular co-ordination; increasing delicacy and complexity of muscular movements. Thus the ontogeny of the brain recapitulates its phylogeny.

THE BRAIN AND PSYCHIC PHENOMENA.

The bearing of the theory of evolution on ideas of creation, design, and kindred subjects may briefly be referred to in connection with our views about the relation of psychic phenomena to the brain.

The study of the human brain in its anatomical, physiological and psychological aspects has brought great thinkers, in all ages, into the presence of phenomena that still baffle some of the most subtle philosophers. Here we meet with such realities as self-consciousness, perception, intellection and volition. Are these material entities of such character that we may say they are exclusively products of the activity of the brain, as the secretion of bile is the product of the activity of the liver, as Cabanis taught? To us it seems clear that such is not the case. One cannot take the specific gravity of love or hate, of fear or joy, as one can that of bile; one cannot find a single physical characteristic in any psychic phenomenon. The most physical of all mental processes, viz., perception, has its psychological as well as its physiological phases. The instreaming, through the senses, of impressions from the external world, may be traced by the physiologist along the different nerves of the body to the cortex cells of the brain. All the phenomena that occur at and between these cortex cells and the peripheral endings of the nerves may be formulated in terms of molecular physics. But not so with that consciousness of these impressions which we call perception. In the light of the present knowledge that we possess, it seems to us that the only induction which the physiologist is warranted in making is that, associated with molecular movements in the brain is the phenomenon of perception. This leaves the field clear for each thinker to speculate about the subject in such manner as seems to him most rational. And the history of philosophy shows that many thinkers have formulated theories upon the subject that range in character from the materialism of Büchner to the idealism of Berkeley.

The view which teaches that psychic phenomena are correlated with the physiological phenomena of the brain; that these phenomena have undergone parallel[17] evolution, and “are as inseparable as are the two sides of a sheet of paper” (Dr. Carus), appeals to us as the most comprehensible one and at the same time the one most in consonance with the known phenomena. We accept the view, then, that there is a mind immanent in the brain.[18] The mind is conscious of its personality; conscious of the external world through the innumerable perceptions which reach it through the nervous system; conscious of its power to build its percepts into concepts, and to reason about them; conscious of its power of choice and of causing motion; and conscious of itself, therefore, as a cause in producing effects; and, finally, it is conscious of its power to adapt means to an end,—in short, it knows that it has the power to design.

These facts are at the bottom of much of the philosophy of the present and the past. The untutored savage, knowing that his personality can cause motion, and beholding moving objects in nature, instinctively made the induction that all these objects had personalities behind them. He saw a spirit in his own voice that came back to him as an echo from the rocks; he saw a personality in his shadow; he saw personalities in falling stones, in running brooks, in waving foliage; he beheld them in the raging tempest, in the thunder and the lightning, as well as in the blazing sun and the twinkling stars; he saw spirits in the dead that came back to him in dreams. In short, he recognized a separate personality in every isolated phenomenon in nature. The child talking to its doll, petting it, rebuking it, or whipping it; Xerxes castigating the ocean for wrecking his ships, are illustrations of the strong human tendency to project (or eject)[19] personalities into the inanimate objects of nature. This natural, but lowly, phase of culture and philosophy is known as Fetichism.

As encephalic and psychic evolution advanced; as men, with wider knowledge and broadening experience, ascertained the laws that govern the isolated phenomena of nature, the separate beings in every distinct object and occurrence vanished from thought; but they still beheld a separate personality in every great department of nature. The Romans, for instance, saw Neptune as God of the Ocean, Pluto as God of the lower world, Jupiter as God of the Heavens, and so on. This phase of culture and philosophy, and therefore of religion, is Polytheism.

In the two phases of culture now briefly outlined the personalities were grossly anthropomorphic. They were like human beings, capricious, revengeful, subject to flattery, good and evil, and were therefore to be placated and cajoled by sacrifices and offerings.

Psychic evolution continuing, there appeared from time to time great thinkers who saw one “Infinite Personality” behind the cosmos.[20] This “personality” is still in every phenomenon, though no longer as a separate soul, but only as the separate manifestation of the Soul of the Universe. This is Monotheism, a phase of culture which marks the culmination of philosophy and religion through psychic evolution.

Our knowledge of the universe can be only a shadowy symbol of the reality. The poverty of language is so great and the power of thought so limited that the most subtle philosopher can form only an empty symbol of the cosmic soul. The most ethereal symbols of the greatest thinkers are necessarily incomplete in detail and anthropomorphic, in order to be intelligible. The history of philosophy and religion shows that with the evolution of mind and the acquisition of knowledge, the anthropomorphic ideas of the soul of the cosmos become less crudely coarse and vulgar, until the most elevated and refined ideas of monotheism are reached. But even these refined ideas about the soul of the universe are necessarily anthropomorphic, though in a vastly less degree than in the lower phases of culture. One’s conceptions of this all-pervading soul immanent in the universe are therefore profoundly modified by one’s kind and degree of culture. In the words of Professor Fiske, the great scholar and subtle thinker who has delved in the deepest mines of philosophy and come forth weary and heavy-laden with their boasted treasures, has framed a very different conception of God from that entertained by the priest at the confessional.

A study of the human brain, then, and the soul resident therein prepares us to believe that the cosmos has a soul (God) immanent in it. We can readily grasp the idea that the soul of the cosmos may be self-conscious, wills, thinks, acts, and designs.

This cosmic soul has been and is active in creation. In a low phase of culture every distinct object of nature is looked upon as a separate creation—a manufacture. With the progress of science the conception of separate creative acts becomes greatly modified. The creative acts are judged to be fewer in number and nobler in character. Finally, that phase of highest culture which recognizes the law of universal evolution, formulates the view of one continuous creative act, in which every object is still a creation but not a separate creation,—only a separate manifestation of one eternal act of creative energy. The history of creation, which means the same thing as the history of evolution, shows innumerable adaptations which may surely be considered as the work of a cosmos designer. Evolution has profoundly modified our conceptions of design in nature as it has those of creation. Every separate work of nature, presents a separate, distinct and man-like design to the uncultured. But, with advancing science, all these separate and petty designs are swallowed up into fewer and grander designs, until at last, through evolution, we reach the magnificent and ennobling conception of one infinite and all-embracing design, persisting through infinite time and extending throughout infinite space, which embraces every apparently separate design.

Thus, while evolution destroys low anthropomorphic notions of the mode of working of the Designer and simplifies while it purifies and vastly ennobles our conceptions of this Designer, it yet replaces as much teleology as it destroys. But the highest conceptions that the subtlest philosophers are able to form of a cosmic Designer are necessarily anthropomorphic in some degree, for they can only think in man-like ways.

We have seen in earlier pages of this book how, throughout the incalculable ages of geologic time, innumerable living forms have come upon the stage at different epochs, the forms of one epoch being transmutations from those of an earlier one, and so on, back to the beginning of life. The theory of universal evolution teaches that in the abysmal depths of still earlier æons there was a time when no life existed on the globe, for the globe was then a whirling ball of intensely hot vapor; still further back there was a time when this ball of vapor had not yet been born from that giant nebula—the primitive sun. Through all the sweep of infinite time we see the multitudinous objects of nature coming into existence, one after another, from primeval vapor, and in accordance with laws the character and scope of which we begin to partially understand. It is after the recounting of such well-known facts as these that Professor Fiske makes the statement that Paley’s simile of the watch is no longer applicable to such a world as ours. It must be replaced, he says, by the simile of the flower; for the universe is not a machine, but an organism with an indwelling principle of life; the world was not made offhand, it has grown from more primitive conditions.

In studying the Diagram of Development (Fig. 18) it will be observed that man is the highest and greatest fruitage of the tree of animal life. He is the highest animal in the taxonomic series, as he is in the phylogenic series. He has been the goal, and is the completion of organic evolution. As Dana says, “there is a prophecy of man which runs through the whole of geologic history, which was uttered by the winds and waves at their work over the sands, by the rocks in each movement of the earth’s crust, and by every living thing in the long succession, until man appeared to make the mysterious announcements intelligible.”

The vital path from primitive protozoan to man has been a straight and narrow one, and innumerable groups of animals have branched off laterally. In so doing they departed forever from the man-ward path, and developed obliquely along the diverging roads and bypaths of lower life organizations. They may diverge still farther from the original parting point, but can never get back into the man-ward road. They have lost the golden opportunity and can never regain it.

Man is not only the highest creature that has ever appeared on the globe, but it seems a safe induction to say that he is also the highest animal that evolution will ever develop here.[21] Evolution, through Natural Selection and other agencies, having spent most of its force in creating the innumerable species of animals and plants that have lived in the past and that are now living on the globe to-day, and having had as its goal the creation of that highest and noblest of all creatures—man—is now concentrating its force in further evolving man. Anatomists have reasons to believe that man is now evolving, in many portions of his body, as rapidly as did the horse through Tertiary Ages. Evolution is pushing him on to higher and higher planes, along the straight and perpendicular man-ward track that he has traveled from his protozoan ancestors; while his simian relatives are diverging obliquely more and more from the man-ward track. Through Natural Selection and rational selection evolution seems now to be spending its main force especially on one particular part of man’s body, viz.: his brain and its immanent mind.

The brain of a living, highly civilized man is larger than the brains of men of the tenth century; the brains of these latter are larger than those of palæolithic men. Evolution, having raised the body of man to nearly its highest possible level, is now perfecting more and more his brain, and therefore his thinking power, or, better, his mind. Through his intelligence he is eliminating more and more the noxious plants and dangerous animals that surround him, and is preserving and improving those that are useful to him, and thereby making the organic world more and more subservient to his purposes. He is even getting larger and larger control over the mechanical, physical, and chemical forces of nature, and the possibilities of his improvement in these directions are almost boundless. Evolution for man now means psychic evolution, social evolution; in short, civilization.

From what has been said it can readily be perceived that man, zoölogically and psychologically, is by far the most important creature on the globe. He seems to be the goal towards which evolution has been steadily advancing throughout the geologic ages. It is for these reasons that we believe no higher animal than man will be evolved on the earth. Man himself will continue to evolve higher and higher. Well may we say, with Sir William Hamilton, that there is nothing great in the world but man, and nothing great in man but mind. Is it a shallow philosophy which teaches that it was through design that this most important creature was evolved as the topmost flower on the highest and straightest branch of the tree of life? We do not think so. One of the most profoundly interesting facts to be observed in that higher evolution—psychic evolution—which is now mostly molding man, is the fact of rational selection supplementing and largely replacing Natural Selection. With the creation of man, choice or will comes in as a factor of ever-increasing importance. The active will to use certain capacities and disuse others will play a part in the further development of man of ever-increasing importance and widening influence. Use and disuse have been factors of commanding importance in modifying the bodies and minds of the animal forms that led up to man. Use and disuse will be factors of commanding influence in profoundly modifying the brain, and therefore the mental constitution of man as he advances in social evolution. The use of the brain along chosen lines will, on well-known physiological principles, increase its organization and therefore its power for manifesting psychic phenomena. These two factors will continue to act and react in the future as they have in the past, increased psychical activity enlarging the brain, and the more highly organized brain augmenting the psychic phenomena. What is true of the mind in general is also true of its varied manifestations. The history of psychic evolution gives reason to believe that not only will the capacity for thought be augmented and the power of the will increased in future, but also the strength of selfishness will still further be weakened by disuse and the power of sympathy augmented by practice. As our half-human ancestors were evolving man-ward, and Natural Selection was augmenting their brains, thus increasing their capacity for thought and, therefore, their capacities for more varied experiences through life, there was a concomitant increase in the period of infancy. The activities of the lower animals are mostly of a simple character. They are for the purpose of securing food, escaping enemies, and reproducing their kind. These activities are comparatively so simple and have been repeated so often, generation after generation for ages, that they have become thoroughly organized, by heredity, in the offspring before they are born. When the offspring are born they seek their food, they endeavor to avoid enemies, and in due time procreate their kind without any teaching. With them heredity is almost everything, and experience exceedingly small. These facts can well be exemplified in studying the young of such animals as fishes, amphibians, and reptiles. In the higher birds and mammals Natural Selection has so augmented the size of the brain that their psychic capacities are greatly increased. This increased intelligence is accompanied with an augmented variety and complication of experiences. The acts performed by animals now become so complex, numerous, and varied that they are repeated with much less frequency than are the acts of animals lower in the scale. Consequently, heredity has not had sufficient time to so mold them into the germ-cells that they unfold as perfect reflex or instinctive acts at birth. The hereditary units that carry these acquired experiences of the parents in the developing embryo lie dormant for a while and unfold slowly under the teaching and protection of the parents for a varying period known as infancy. As Natural Selection still further evolved the brains of our advancing half-human ancestors, thus increasing their intelligence and making their lives more replete with complex and varied experiences, there was a concomitant prolongation of the period of infancy—the period of helplessness and dependency. During this evolution of infancy Natural Selection compelled the parents, especially the mother, to possess feelings other than those of utter selfishness. They had to give thought not only to themselves but also to the helpless creatures they brought into the world. The offspring increasing in numbers, all associated together in varying degrees of helpless infancy and dependent upon the care and protection of common parents, the relationships of mother and father, brother and sister, must by degrees have become more and more intimate as evolution proceeded, until finally that social unit appears—the family. In the family personal selfishness can no longer be the exclusively dominant motive to action. Rudimentary sympathies appear. The individuals must conduct themselves so as not to jeopardize the interests of the family. Thus other interests than those of a purely personal character must influence their actions. And thus, finally, the adumbrations of right and wrong conduct appear, and we now find in the newly-created human species the germs of morality and conscience. As social evolution proceeded, the self-regarding faculties were more and more curtailed, and the other-regarding sentiments were extended with ever-enlarging amplitude. Sympathy and helpfulness for others were broadened more and more, including first the clan, then the tribe, then the nation, and, finally, groups of the latter were welded into empires. And the writing on the wall seems to indicate the future federation of all the nations.

Among primeval men, who obtained their food by hunting out such edible objects as were already in existence, war was universal. The supply of fruit, fish, and game being strictly limited, men were compelled to fight under penalty of starvation. As intelligence advanced and men learned to cultivate useful plants and to domesticate animals, and as they learned further to exchange by barter the products of their labor, a much greater population could live upon a given area. These tribes would be more powerful than their neighbors who still lived by hunting, fishing, and such like, and would flourish at their expense. Through agriculture and commerce men slowly learned that one man’s interest was not necessarily opposed to another’s; they also learned, though it may be ever so feebly, that fighting and plundering one another hindered rather than promoted their welfare. Thus man slowly evolved from a primitive, predatory civilization, in which war was universal and chronic, to the higher industrial civilization, in which war is much less frequent and less universal. Out of this primitive industrial civilization, which has grown more and more complex with the passing years, have come the arts and sciences, which give such added interest and value to modern life. This evolving industrial civilization, by furnishing a wider basis for political union through community of interest instead of mere blood-relationship, has greatly extended the field over which moral obligations are recognized as binding.[22] Social evolution is tending to eradicate more and more, through disuse, the brutish instincts of man; weakening his fighting propensities, his cruelty, his selfishness, his passions; and strengthening, by use, his sympathies, his kindness, his mercy, his sense of justice and honor, and his charity. The goal of social evolution seems to be men of character,—men with the widest possible knowledge of the laws of nature, physical, intellectual, and moral; and with the desire and will to rightly obey these laws. Such men will be both loving and lovable characters. In view of this may we not supplement Sir William Hamilton’s aphorism, and say that there is nothing great in mind but character? Since evolution is producing such characters, though it may be seemingly ever so slowly, is it again a shallow philosophy which teaches that there is a designer unfolding these characters? We do not think so. And if there is a designer who has been making towards this goal throughout the infinite sweep of bygone ages, do we not have at least some faint adumbration of knowledge as to the character of this designer? It seems to us that we do. Well may we say, with Matthew Arnold, that there is immanent in the cosmos an eternal soul, not ourselves, that makes for righteousness. This double assertion, that there is a soul in the universe outside of ourselves, and that this soul makes for right conduct, is the basis of fundamental importance in all religions. There are many religions in the world, and many creeds of the one great religion of christendom. They differ in many of the transcendental doctrines that they teach, and in many of the rules of conduct that they prescribe for their adherents; but they all contain as their most fundamental and vitally important basis the double assertion that there is a soul of the universe, and that this soul makes for right conduct. The assertion may be thickly overlaid with superstitions and petty rites by the untrained and dull intelligence of low races, as in the Eskimos; or it may attain a high degree of development and perfection, as among the Jews. The refinement and beauty of the double conception are more and more enhanced with social evolution. Just in proportion as civilization advances, and men come to reason more carefully and entertain wider views of life, just to that extent do they come to value more highly the essential truths of religion, while they attach less and less importance to many superficial details. It is of vastly greater moment to us that there is a cosmic soul in the universe that makes for righteousness than that this soul is threefold or onefold in its transcendental nature. Also of vastly more moment to us is a belief in this soul than any opinions we may entertain about eating meat on Friday or listening to attractive music on Sunday. A thoughtful mind, penetrated with the conviction of the truth of evolution, entertains views on all subjects pertaining to man, very different from those held by one not familiar with the great theory. His conceptions of the first Adam are profoundly modified by a flood of facts. If this flood sweep him on irresistibly, and equally profoundly modifies his conceptions of the second Adam, can it not be seen that even this is a fact of small significance compared with that other fact of overwhelming importance, viz.: the fact of the existence in the universe of a cosmic soul that makes for righteousness? Man is essentially a religious animal, and there is a very substantial philosophical basis for his religion.[23] His religion may be highly colored with emotion, or it may be coldly philosophical. When Herbert Spencer speaks of the eternal Power in the universe which makes for righteousness and is manifested in every event of the universe as the Unknowable, does he not do what Holy Writ has already done? “Canst thou find out the Almighty unto perfection?” When Carlyle speaks of the Universe as in very truth the star-domed city of God, and reminds us that through every crystal and through every grass blade, but most through every living soul, the glory of a present God still beams, he means much the same thing that Mr. Spencer does when he speaks of a Power that is inscrutable in itself, yet is revealed from moment to moment in every throb of the mighty rhythmic life of the universe. The only difference is that Mr. Spencer speaks in the colorless, precise, and formal language of science, while Carlyle’s language is colored by emotion; is, in fact, poetical.[24]

EVOLUTION AND SOCIAL PROBLEMS.

The relation of evolution to many social problems of vital importance is a fascinating as well as very extensive subject. We have only space to say that in order to understand the normal actions, as well as the abnormal ones, of the members of society, and in order, therefore, to understand and inaugurate rational methods of conducting education, minimizing pauperism, vice, disease, and crime, it must constantly be borne in mind that two great streams of tendencies have come down from the ages in the germ cells—what we may call the diseased and animal tendencies on the one hand, and the distinctively human and healthy tendencies on the other.

The most characteristic of the human tendencies are abstract thought and reflection, and therefore the power of choice or will, and altruism.

Also it must be borne in mind that environment is a force of commanding influence. This environment (which the individual may make for himself to a limited extent) may be propitious or adverse to the best human and normal tendencies. The relative preponderance of the animal or the human, the healthy, or the diseased tendencies, taken in conjunction with the character of the environment, stamp man’s actions as normal (and therefore right or wrong) or as abnormal, and therefore irresponsible. Not to discriminate between such normal and abnormal persons is not in accordance with either common morality or common sense. Neither is it in accord with common sense, or morality, or humanity, for society to deal with its habitual criminals and paupers, and subjects of hereditary disease, in the utterly irrational manner that it does. When society takes away from the criminal his personal liberty and places him in an environment that theoretically reforms him and protects itself, why does it not take cognizance of the fact that its theories are often woful failures in practice? The criminal is often not reformed and he gets into the category of habitual offenders; but society permits him, during his intervals of freedom, to procreate his kind and send his polluted cargoes of vicious heritages to helpless offspring. Is this humanity to these offspring? It is the grossest inhumanity! Does society protect itself by its intermittent detentions of habitual criminals? It probably breeds three habitual criminals while it is failing in its efforts to reform one. It is mostly by Nature’s prematurely killing off incorrigible criminals by their diseases and intemperance, that these social pests are kept within due bounds, and not through reformations accomplished in improperly conducted prisons. It seems to us that every consideration of justice and humanity cries aloud for the destruction of the procreating glands in habitual criminals.[25] Castration should go hand in hand with detention behind prison bars. Why should the habitual drunkard, for instance, be permitted to evolve his poisoned germ cells into helpless beings, giving them diseased bodies and vitiated moral characters, thus foredooming them to life-long physical ailments and moral turpitude? Removal of the procreating glands should be the penalty for chronic alcoholism. In objection to this suggestion, some may prate of personal liberty. What a multitude of outrages and brutalities the broad mantle of personal liberty is often made to cover! In allowing personal liberty to an undeserving individual, which more often means unbridled license to that individual, a whole generation of offspring are frequently enslaved by poverty, vice, crime, and disease in its manifold manifestations. During organic evolution Natural Selection has been incessantly on the watch for weaknesses of any kind, ruthlessly exterminating the helpless, the weak, the sick, and those that in any way are unfit. In social evolution Natural Selection has often been of necessity no less ruthless. But during social evolution characters that are unfolding more and more loving and lovable traits have so largely subordinated Natural Selection as to permit the helpless, the old, the sick, and the unfit, to live, thus strengthening those highest attributes of the greatest minds, viz.: intelligent sympathy, pity and love.

But it seems to us that the highest altruism, in dealing kindly with an abnormal, possible parent, will not continue long to stupidly overlook the weighty rights of unborn children. Human selection of the socially unfit will be dominated more and more, as social evolution unfolds its fruits, by those minds that are advancing to the highest goals of evolution, viz.: large minds of high character—widely informed minds, of strong will and broad sympathies. And under these circumstances we may hope that unborn generations will not be given over to total oblivion.

Well may we repeat, before concluding this little book, that man is not only a creature of the present, but profoundly a product of the abysmal ages of a bygone eternity. He is not only a composite chip of many old human blocks, but of innumerable geologic ancestral blocks. He has in his constitution simian, reptilian, piscine, and innumerable other chips, so to speak, and is indeed of the earth earthy; for studies in heredity not only illustrate the continuity of the human race, but also clearly indicate the continuity of this race with more lowly animals. Man has in his structure the indelible impress of the handiwork of these lowly relatives. Upon him, as upon them, and upon all living creatures, the forces of heredity and variation, of use and disuse, of environment and Natural Selection, have been and are perpetually playing, evolving him in one direction and innumerable creatures in other directions.

The goal of evolution seems to be men with Great Minds of High Character. There is nothing great in the world but man, nothing great in man but mind, and nothing great in mind but character.