The psychology of civilised man, though derived from that of the savage, and hence resembling it fundamentally, is, nevertheless, very different from it, both in character and in what it contains. The mind of the savage is rude, unresourceful, vicious, and childlike, while that of the civilised man or woman may be overflowing with wisdom and benignity. This gulf has not been covered by a stride, but by the slow operation of the same laws of Inheritance, Variation, and Selection by which all progress has been brought about. 7. Degeneration is a necessary part of the process of organic evolution. All progress, whether anatomical, intellectual, or social, takes place through selection, and selection means the pining and ultimate passing away of that which is left. In individual evolution it is organs, ideas, and traits of character that are eliminated, and in social evolution it is customs and institutions. One of the reasons given in the preceding chapter for the belief in the evolution of structures is the existence in man and other animals of _vestigial organs_, organs which in lower forms of life are useful, but which in higher forms are represented by useless or even injurious remnants. Similar remnants are found in the _psychology_ of man and other animals. These vestiges of mind are not so easily recognised as the vestiges of structure, but they are everywhere. We find them in the antiquated instincts of man and the domestic animals, in the silent letters and worn-out words of languages, and in the emaciated remains of abandoned beliefs and institutions. The hunting and fishing instinct of civilised man is a vestigial instinct, normal in the savage, but without either sense or decency among men devoted to industrial pursuits. The savage hunts and fishes because he is hungry, never for pastime; civilised men and women do so because they are too mechanical to assort their impulses. Civilised man is a mongrel, a cross between a barbarian and a god. His psychology is a compound of the jungle and the sky. In their loftier moments, many men are able to obscure the cruder facts of their origin and to put into temporary operation those more splendid processes of mind which characterise their ideals. But even the most civilised are forever haunted by the returning ghosts of departed propensities—propensities which grew up in ages of hate, which are now out-of-date, but which in the trying tedium of daily life come back and usurp the high places in human nature. Revenge, hate, cruelty, pugnacity, selfishness, vanity, and the like, are all more or less vestigial among men who have entered seriously on the life of altruism. Like the vermiform appendix and the human tail, these old obsolete parts of the human mind are destined, in the ripening of the ages, to waste away and disappear through disuse.