The theory of natural selection as expounded by Darwin was so completely successful in explaining the origin of the almost infinitely varied forms of the organic world, step by step, during the long succession of the geological ages, that it was naturally supposed to be equally applicable to mankind. This was thought to be almost certain when, in his later work, The Descent of Man, Darwin proved by a series of converging facts and convincing arguments that the physical structure of man was in all its parts and organs so extremely similar to that of the anthropoid apes as to demonstrate the descent of both from some common ancestor.
So close is this resemblance that every bone and muscle in the human body has its counterpart in that of the apes, the only differences being slight modifications in their shape and position; yet these differences lead to external forms, attitudes, and modes of life so divergent that we can hardly recognise the close affinity that really exists. This affinity is so real and unmistakable that such a great and conservative zoologist as the late Sir Richard Owen declared that to discover and define any important differences between them was the anatomist's difficulty. It was in the dimensions, the shape, and the proportions of the brain that Owen found a sufficient amount of distinctive characters to enable him to place Man in a separate order of mammals—Bimana, or two-handed—while the remainder of the whole monkey tribe—including the apes, baboons, monkeys, and lemurs—formed the order Quadrumana, or four-handed animals. This classification has been rejected by most modern biologists, who consider man to form a distinct family only—Hominidæ—of the order Primates, which order includes all four-handed animals as well as man.
But if we recognise the brain as the organ of the mind, and give due weight to the complete distinctness and enormous superiority of the mind of man as compared with that of all other mammals, we shall be inclined to accept Owen's view as the most natural; and this becomes almost certain when we realise the enormous effect his mind has produced, in modifying and almost neutralising the action of that great law of natural selection which has held supreme sway in every other portion of the organic world.
We have seen in the preceding chapter how every form of organic life during all the vast extent of geological time has been subject to the law of natural selection, which has incessantly moulded their bodily form and structure, external and internal, in strict adaptation to the successive changes of the world around them; while that world was itself hardly, if at all, modified by them. A few isolated cases—such as the formation of islands by the coral-forming zoophytes, or the damming of a few rivers by the rude though very remarkable labours of the beaver—can hardly be considered as forming exceptions to this law.
But so soon as man appeared upon the earth, even in the earliest periods at which we have any proofs of his existence, or in the lowest state of barbarism in which we are now able to study him, we find him able to use and act upon the forces of Nature, and to modify his environment, both inorganic and organic, in ways which formed a completely new departure in the entire organic world.
Among the very rudest of modern savages the wounded or the sick are assisted, at least with food and shelter, and often in other ways, so that they recover under circumstances that to most of the higher animals would be fatal. Neither does less robust health or vigour, or even the loss of a limb or of eyesight, necessarily entail death. The less fit are therefore not eliminated as among all other animals; and we behold, for the first time in the history of the world, the great law of natural selection by the survival only of "the fittest" to some extent neutralised.
But this is only the first and least important of the effects produced by the superior faculties of man. In the whole animal world, as we have seen, every species is preserved in harmony with the slowly changing environment by modifications of its own organs or faculties, thus gradually leading to the production of new species equally adapted to the new environment as its ancestor was before the change occurred.
In the case of man, however, such bodily adaptations were unnecessary, because his greatly superior mind enabled him to meet all such difficulties in a new and different way. As soon as his specially human faculties were developed (and we have as yet no knowledge of him in any earlier condition), he would cease to be influenced by natural selection in his physical form and structure. Looked at as a mere animal he would remain almost stationary, the changes in the surrounding universe ceasing to produce in him that powerful modifying effect which they exercise over all other members of the entire organic world. In order to protect himself from the larger and fiercer of the mammalia he made use of weapons, such as stone-headed clubs, wooden spears, bows and arrows, and various kinds of traps and snares, all of which are exceedingly effective when families or larger groups combine in their use. Against the severity of the seasons he protected himself with a clothing of skins, and with some form of shelter or well-built house, in which he could rest securely at night, free from tempestuous rains or the attacks of wild beasts. By the use of fire he was enabled to render both roots and flesh more palatable and more digestible, thus increasing the variety and abundance of his food far beyond that of any species of the lower animals. Yet further, by the simplest forms of cultivation, he was able to increase the best of the fruits, the roots, the tubers, as well as the more nutritious of the seeds, such as those of rice and maize, of wheat and of barley, thus securing in convenient proximity to his dwelling-place an abundance of food to supply all his wants and render him almost always secure against scarcity or famine or disastrous droughts.
We see, then, that with the advent of Man there had come into existence a being in whom that subtle force we term mind became of far more importance than mere bodily structure. Though with a naked and unprotected body, this gave him clothing against the varied inclemencies of the seasons. Though unable to compete with the deer in swiftness or with the wild bull in strength, this gave him weapons with which to capture or overcome both. Though less capable than most other animals of living on the herbs and the fruits that unaided Nature supplies, this wonderful faculty taught him to govern and direct Nature to his own benefit, and compelled her to produce food for him almost where and when he pleased. From the moment when the first skin was used as a covering, when the first rude spear was formed to assist him in the chase, when fire was first used to cook his food, when the first seed was sown or shoot planted, a grand revolution was effected in Nature—a revolution which in all previous ages of the earth's history had had no parallel. A being had arisen who was no longer subject to bodily change with changes of the physical universe—a being who was in some degree superior to Nature, inasmuch as he knew how to control and regulate her action, and could keep himself in harmony with her, not through any change in his body, but by means of his vast superiority in mind.
The view above expounded of the transference of the action of natural selection from the bodily structure to the mind of early man was my first original modification of that theory, having been communicated to the Anthropological Review in 1864. It received the approval both of Darwin himself and of Herbert Spencer, and I am not aware that anyone has shown any flaw in the reasoning by which it is established. It is certainly of high importance, since if true it renders impossible any important change in the external form of mankind, while it serves as an explanation of the complete identity of specific type of the three great races of man—the Caucasian or white, the Mongolian or yellow, and the Negroid or black—in every essential of human form and structure, while in their best examples they approach very nearly to the same ideal of symmetry and of beauty. Yet so little attention has been given to this view that most popular and even some scientific writers take it for granted that no such difference exists between man and the lower animals. They assume that we are destined to have our bodies modified in the remote future in some unknown way, and that the idea that there is anything approaching final perfection in the human form is a mere figment of the imagination.
Others are so imbued with the universality of natural selection as a beneficial law of Nature that they object to our interfering with its action in, as they urge, the elimination of the unfit by disease and death, even when such diseases are caused by the insanitary conditions of our modern cities or the misery and destitution due to our irrational and immoral social system. Such writers entirely ignore the undoubted fact that affection, sympathy, compassion form as essential a part of human nature as do the higher intellectual and moral faculties; that in the very earliest periods of history and among the very lowest of existing savages they are fully manifested, not merely between the members of the same family, but throughout the whole tribe, and also in most cases to every stranger who is not a known or imagined enemy. The earliest book of travels I remember hearing read by my father was that of Mungo Park, one of the first explorers of the Niger. He was once alone and sick there, and some negro women nursed him, fed him, and saved his life; and while lying in their hut he heard them singing about him as the poor white man, of whom they said:—
Hospitality is, in fact, one of the most general of all human virtues, and in some cases is almost a religion. It is an inherent part of what constitutes "human nature," and it is directly antagonistic to the rigid law of natural selection which has universally prevailed throughout the lower animal world. Those who advocate our allowing natural selection to have free play among ourselves on the ground that we are interfering with Nature, are totally ignorant of what they are talking about. It is Nature herself, untaught, unsophisticated human nature, which they are seeking to interfere with. They seek to degrade the higher nature to the level of the lower, to bring down Heaven-born humanity, in its essential characteristics only a little lower than the angels, to the infinitely lower level of the beasts that perish.
The conclusion reached in the earlier portion of this volume, that the higher intellectual and moral nature of man has been approximately stationary during the whole period of human history, and that the cause of the phenomenon has been the absence of any selective agency adequate to increase it, renders it necessary to give some further explanation as to the probable or possible origin of this higher nature, and also of that admirable human body which also appears to have reached a condition of permanent stability.