But besides this lofty intellect, man is gifted with what we term a moral sense: an insistent perception of justice and injustice, of right and wrong, of order and beauty and truth, which as a whole constitute his moral and æsthetic nature, the origin and progress of which I have endeavoured to throw some light upon in the present volume. The long course of human history leads us to the conclusion that this higher nature of man arose at some far distant epoch, and though it has developed in various directions, does not seem yet to have elevated the whole race much above its earliest condition, at the time when, by the influx of some portion of the spirit of the Deity, man became "a living soul." We will now consider some of the changes which this higher nature of man has produced in the action of the laws of variation and natural selection. These are very important, and are so little understood that almost all popular writers on the subject of the future of mankind are led into stating as scientific conclusions what are wholly opposed to the actual teaching of evolution. CHAPTER XIV SELECTION AS MODIFIED BY MIND 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.