Not only are the bodies, but also the minds of man constructed on the same pattern as those of the lower animals. And if we examine the minds of the lower animals, we find in them the rudiments of our talents and our virtues. As the beautiful yet imperfect human body has been slowly developed from the base and hideous creatures of the water and the earth, so the beautiful yet imperfect human mind has been slowly developed from the instincts of the lower animals. All that is elevated, all that is lovely in human nature has its origin in the lower kingdom. The philosophic spirit of inquiry may be traced to brute curiosity, and that to the habit of examining all things in search of food.
Artistic genius is an expansion of monkey imitativeness.
Loyalty and piety, the reverential virtues, are developed from filial love. Benevolence and magnanimity, the generous virtues, from parental love. There is a certain class of people who prefer to say that their fathers came down in the world through their own follies rather than to boast that they rose in the world through their own industry and talents. It is the same shabby-genteel sentiment, the same vanity of birth which makes men prefer to believe that they are degenerated angels, rather than elevated apes. In scientific investigations such whims and fancies must be set aside.