them, it is admitted that the souls of the dead come back to the living during their sleep. This theory was the more readily accepted because no fact of experience could invalidate it. But these dreams were possible only where the ideas of spirits, souls and a land of the dead were already existent, that is to say, where religious evolution was relatively advanced. Thus, far from having been able to furnish to religion the fundamental notion upon which it rests, they suppose a previous religious system, upon which they depended.[113] III We now arrive at that which constitutes the very heart of the doctrine. Wherever this idea of a double may come from, it is not sufficient, according to the avowal of the animists themselves, to explain the formation of the cult of the ancestors which they would make the initial type of all religions. If this double is to become the object of a cult, it must cease to be a simple reproduction of the individual, and must acquire the characteristics necessary to put it in the rank of sacred beings. It is death, they say, which performs this transformation. But whence comes the virtue which they attribute to this? Even were the analogy of sleep and death sufficient to make one believe that the soul survives the body (and there are reservations to be made on this point), why does this soul, by the mere fact that it is now detached from the organism, so completely change its nature? If it was only a profane thing, a wandering vital principle, during life, how does it become a sacred thing all at once, and the object of religious sentiments? Death adds nothing essential to it, except a greater liberty of movement. Being no longer attached to a special residence, from now on, it can do at any time what it formerly did only by night; but the action of which it is capable is always of the same sort. Then why have the living considered this uprooted and vagabond double of their former companion as anything more than an equal? It was a fellow-creature, whose approach might be inconvenient; it was not a divinity.[114]