3. Imitation and Social Psychology. We have already noted the defects of a psychology of learning which places the individual mind naked, as it were, in contact with physical objects, and which believes that knowledge, ideas, and beliefs accrue from their interaction. Only comparatively recently has the predominating influence of association with fellow beings in the formation of mental and moral disposition been perceived. Even now it is usually treated as a kind of adjunct to an alleged method of learning by direct contact with things, and as merely supplementing knowledge of the physical world with knowledge of persons. The purport of our discussion is that such a view makes an absurd and impossible separation between persons and things. Interaction with things may form habits of external adjustment. But it leads to activity having a meaning and conscious intent only when things are used to produce a result. And the only way one person can modify the mind of another is by using physical conditions, crude or artificial, so as to evoke some answering activity from him. Such are our two main conclusions. It is desirable to amplify and enforce them by placing them in contrast with the theory which uses a psychology of supposed direct relationships of human beings to one another as an adjunct to the psychology of the supposed direct relation of an individual to physical objects. In substance, this so-called social psychology has been built upon the notion of imitation. Consequently, we shall discuss the nature and role of imitation in the formation of mental disposition. According to this theory, social control of individuals rests upon the instinctive tendency of individuals to imitate or copy the actions of others. The latter serve as models. The imitative instinct is so strong that the young devote themselves to conforming to the patterns set by others and reproducing them in their own scheme of behavior. According to our theory, what is here called imitation is a misleading name for partaking with others in a use of things which leads to consequences of common interest. The basic error in the current notion of imitation is that it puts the cart before the horse. It takes an effect for the cause of the effect. There can be no doubt that individuals in forming a social group are like-minded; they understand one another. They tend to act with the same controlling ideas, beliefs, and intentions, given similar circumstances. Looked at from without, they might be said to be engaged in "imitating" one another. In the sense that they are doing much the same sort of thing in much the same sort of way, this would be true enough. But "imitation" throws no light upon why they so act; it repeats the fact as an explanation of itself. It is an explanation of the same order as the famous saying that opium puts men to sleep because of its dormitive power.