But science also may become mere animal training. Each science is a profession, acquired as a technical training like learning a trade. Of things outside his own trade the scientist may be quite ignorant and lacking in curiosity. He is often unable to see the significance of his specialty for knowledge as a whole. Within his chosen field of study he may come to resent new discovery--especially if it fails to confirm some favorite theory. In some of the sciences, notably psychology, biology, medicine and the social sciences, there are intense partisan divisions, often rivalling in dogmatism and bitterness, those of theology. Each “school” develops its cult ideas, its jargon credo, and ritual. Herd opinion holds sway over scientists as over other men. Certain phrases and mannerisms are adopted, just as among Rotarians, because they show that one belongs to the crowd. The psychologist today, for instance, must boast his ignorance of philosophy and make a noise like a biologist. The advancement of knowledge is by no means the sole motive in scientific training; there is also much molding to type even though this latter objective is in conflict with the spirit of science itself. Much contemporary educational philosophy is openly and avowedly a technique of animal training; so much so that it quite properly borrows its pedagogical principles from animal psychology. It would be difficult to over estimate the importance of animal experimentation for modern theories of education. Schools of education are deeply interested in the psychology of the learning process. Education is learning, and learning is habit formulation. Habits are the acquired modes of response of men and animals. They may be organized in the nervous tissue by any environmental factors which “condition” certain reflexes; that is, chain certain responses to given stimuli. It is possible for an animal experimenter or an educator of children to organize the environmental situation in such a manner that definite systems of desired responses may be regularly obtained whenever a stimulus of a certain kind is given. A simple and well-known experiment which will serve to explain what we mean by the conditioned reflex is that of Pavlov. A hungry dog when shown meat secretes saliva. At the time the dog sees the meat a bell is rung. This is repeated a number of times until the dog will secrete saliva at the sound of the bell, without the presence of the meat stimulus. The saliva response, induced by the bell stimulus, is the conditioned reflex.