It is generally taken for granted that men inherited some guiding instincts from their beast ancestry, and it may be true, although it has never been proved. If there were such inheritances, they controlled and aided the first efforts to satisfy needs. Analogy makes it easy to assume that the ways of beasts had produced channels of habit and predisposition along which dexterities and other psycho-physical activities would run easily. Experiments with new born animals show that in the absence of any experience of the relation of means to ends, efforts to satisfy needs are clumsy and blundering. The method is that of trial and failure, which produces repeated pain, loss, and disappointments. Nevertheless, it is the method of rude experiment and selection. The earliest efforts of men were of this kind. Need was the impelling force. Pleasure and pain, on the one side and the other, were the rude constraints which defined the line on which efforts must proceed. The ability to distinguish between pleasure and pain is the only psychical power which is to be assumed. Thus ways of doing things were selected which were expedient. They answered the purpose better than other ways, or with less toil and pain. Along the course on which efforts were compelled to go, habit, routine, and skill were developed. The struggle to maintain existence was carried on, not individually, but in groups. Each profited by the other's experience; hence there was concurrence toward that which proved to be most expedient. All at last adopted the same way for the same purpose; hence the ways turned into customs and became mass phenomena. Instincts were developed in connection with them. In this way folkways arise. The young learn them by tradition, imitation, and authority. The folkways, at a time, provide for all the needs of life then and there. They are uniform, universal in the group, imperative, and invariable. The operation by which folkways are produced consists in the frequent repetition of petty acts, often by great numbers acting in concert or, at least, acting in the same way when face to face with the same need. The immediate motive is interest. It produces habit in the individual and custom in the group. It is, therefore, in the highest degree original and primitive. Out of the unconscious experiment which every repetition of the ways includes, there issues pleasure or pain, and then, so far as the men are capable of reflection, convictions that the ways are conducive to social welfare. When this conviction as to the relation to welfare is added to the folkways, they are converted into mores, and, by virtue of the philosophical and ethical element added to them, they win utility and importance and become the source of the science and the art of living.