A fact confirms this interpretation. We have seen that according to the testimony of Strehlow, the Arunta distinguish two sorts of souls: on the one hand are those of the ancestors of the Alcheringa, on the other, those of the individuals who actually compose the active body of the tribe at each moment in history. The second sort only survive the body for a relatively short time; they are soon totally annihilated. Only the former are immortal; as they are uncreated, so they do not perish. It is also to be noticed that they are the only ones whose immortality is necessary to explain the permanence of the group; for it is upon them, and upon them alone, that it is incumbent to assure the perpetuity of the clan, for every conception is their work. In this connection, the others have no part to play. So souls are not said to be immortal except in so far as this immortality is useful in rendering intelligible the continuity of the collective life. Thus the causes leading to the first beliefs in a future life had no connections with the functions to be filled at a later period by the institutions beyond the tomb. But when that had once appeared, they were soon utilized for other purposes besides those which had been their original reasons for existence. Even in the Australian societies, we see them beginning to organize themselves for this other purpose. Moreover, there was no need of any fundamental transformation for this. How true it is that the same social institution can successively fulfil different functions without changing its nature! VI The idea of the soul was for a long time, and still is in part, the popular form of the idea of personality.[865] So the genesis of the former of these ideas should aid us in understanding how the second one was formed. From what has already been said, it is clear that the notion of person is the product of two sorts of factors. One of these is essentially impersonal: it is the spiritual principle serving as the soul of the group. In fact, it is this which constitutes the very substance of individual souls. Now this is not the possession of any one in particular: it is a part of the collective patrimony; in it and through it, all consciousnesses communicate. But on the other hand, in order to have separate personalities, it is necessary that another factor intervene to break up and differentiate this principle: in other words, an individualizing factor is necessary. It is the body that fulfils this function. As bodies are distinct from each other, and as they occupy different points of space and time, each of them forms a special centre about which the collective representations reflect and colour themselves differently. The result is that even if all the consciousnesses in these bodies are directed towards the same world, to wit, the world of the ideas and sentiments which brings about the moral unity of the group, they do not all see it from the same angle; each one expresses it in its own fashion.