contacts is by so much enlarged; the social world is by so much extended. In other words, the realm of the social is the realm of circuits of reciprocal influence between individuals and the groups which individuals compose. The general term "contact" is proposed to stand for this realm, because it is a colorless word that may mark boundaries without prejudging contents. Wherever there is physical or spiritual contact between persons, there is inevitably a circuit of exchange of influence. The realm of the social is the realm constituted by such exchange. It extends from the producing of the baby by the mother, and the simultaneous producing of the mother by the baby, to the producing of merchant and soldier by the world-powers, and the producing of the world-powers by merchant and soldier. The most general and inclusive way in which to designate all the phenomena that sociology proper considers, without importing into the term premature hypotheses by way of explanation, is to assert that they are the phenomena of "contact" between persons. In accordance with what was said about the division of labor between psychology and sociology, it seems best to leave to the psychologist all that goes on inside the individual and to say that the work of the sociologist begins with the things that take place between individuals. This principle of division is not one that can be maintained absolutely, any more than we can hold absolutely to any other abstract classification of real actions. It serves, however, certain rough uses. Our work as students of society begins in earnest when the individual has become equipped with his individuality. This stage of human growth is both cause and effect of the life of human beings side by side in greater or lesser numbers. Under those circumstances individuals are produced; they act as individuals; by their action as individuals they produce a certain type of society; that type reacts on the individuals and helps to transform them into different types of individuals, who in turn produce a modified type of society; and so the rhythm goes on forever. Now the medium through which all this occurs is the fact of contacts, either physical or spiritual. In either case, contacts are collisions of interests in the individuals. 2. The Land and the People[122]