What led to the formulation of these names is the insight into the very remarkable conceptions of nature and the world of those primitive races known to us from history and from our own times. These races populate the world with a multitude of spiritual beings which are benevolent or malevolent to them, and attribute the causation of natural processes to these spirits and demons; they also consider that not only animals and plants, but inanimate things as well are animated by them. A third and perhaps the most important part of this primitive ‘nature philosophy’ seems far less striking to us because we ourselves are not yet far enough removed from it, though we have greatly limited the existence of spirits and to-day explain the processes of nature by the assumption of impersonal physical forces. For primitive people believe in a similar ‘animation’ of human individuals as well. Human beings have souls which can leave their habitation and enter into other beings; these souls are the bearers of spiritual activities and are, to a certain extent, independent of the ‘bodies’. Originally souls were thought of as being very similar to individuals; only in the course of a long evolution did they lose their material character and attain a high degree of ‘spiritualization’[92]. Most authors incline to the assumption that these soul conceptions are the original nucleus of the animistic system, that spirits merely correspond to souls that have become independent, and that the souls of animals, plants and things were formed after the analogy of human souls. How did primitive people come to the peculiarly dualistic fundamental conceptions on which this animistic system rests? Through the observation, it is thought, of the phenomena of sleep (with dreams) and death which resemble sleep, and through the effort to explain these conditions, which affect each individual so intimately. Above all, the problem of death must have become the starting point of the formation of the theory. To primitive man the continuation of life--immortality--would be self-evident. The conception of death is something accepted later, and only with hesitation, for even to us it is still devoid of content and unrealizable. Very likely discussions have taken place over the part which may have been played by other observations and experiences in the formation of the fundamental animistic conceptions such as dream imagery, shadows and reflections, but these have led to no conclusion[93].