But if this theory of totemism has enabled us to explain the most characteristic beliefs of this religion, it rests upon a fact not yet explained. When the idea of the totem, the emblem of the clan, is given, all the rest follows; but we must still investigate how this idea has been formed. This is a double question and may be subdivided as follows: What has led the clan to choose an emblem? and why have these emblems been borrowed from the animal and vegetable worlds, and particularly from the former? That an emblem is useful as a rallying-centre for any sort of a group it is superfluous to point out. By expressing the social unity in a material form, it makes this more obvious to all, and for that very reason the use of emblematic symbols must have spread quickly when once thought of. But more than that, this idea should spontaneously arise out of the conditions of common life; for the emblem is not merely a convenient process for clarifying the sentiment society has of itself: it also serves to create this sentiment; it is one of its constituent elements. In fact, if left to themselves, individual consciousnesses are closed to each other; they can communicate only by means of signs which express their internal states. If the communication established between them is to become a real communion, that is to say, a fusion of all particular sentiments into one common sentiment, the signs expressing them must themselves be fused into one single and unique resultant. It is the appearance of this that informs individuals that they are in harmony and makes them conscious of their moral unity. It is by uttering the same cry, pronouncing the same word, or performing the same gesture in regard to some object that they become and feel themselves to be in unison. It is true that individual representations also cause reactions in the organism that are not without importance; however, they can be thought of apart from these physical reactions which accompany them or follow them, but which do not constitute them. But it is quite another matter with collective representations. They presuppose that minds act and react upon one another; they are the product of these actions and reactions which are themselves possible only through material intermediaries. These latter do not confine themselves to revealing the mental state with which they are associated; they aid in creating it. Individual minds cannot come in contact and communicate with each other except by coming out of themselves; but they cannot do this except by movements. So it is the homogeneity of these movements that gives the group consciousness of itself and consequently makes it exist. When this homogeneity is once established and these movements have once taken a stereotyped form, they serve to symbolize the corresponding representations. But they symbolize them only because they have aided in forming them.