Hyperphysical Animism may be easiest understood as having arisen with the belief in human ghosts. The causes of this belief have been fully set forth by Herbert Spencer[177] and Sir E. B. Tylor[178] in a way that to my mind is convincing. Amongst those causes dreams predominate; wherein the dead are met again as in the flesh. The living body having always been for the savage a conscious force-thing, at death the conscious force leaves the thing or corpse. This might be accepted by him as a fact of the same kind as the loss of its virtue by a talisman or amulet (which is known sometimes to happen), were it not for dreams in which the dead still live. That this conscious force that has left the body is not visible except in dreams need excite little wonder, since many forces natural and magical are invisible. A dream not being common to two men at the same time, the things that are seen in it cannot be pointed out, nor therefore directly named (in this resembling subjective experiences). It was for ages impossible to narrate a dream as a dream: there was no way of distinguishing it from external events, either for the dreamer himself or (were that possible) in reporting it to another. He was far away and met his father, yet had lain by the fire all night! Hence to find names with which to describe such things men turned to other ways in which they seemed to have a double existence, to shadows and reflections: which in their sudden appearance and disappearance, and sometimes faint, sometimes distorted outlines, bear some resemblance to dream-images; and probably it is felt to be significant that shadows and reflections disappear at night, just when dreams occur. Shadows and reflections are not necessarily identified with the ghost derived from the dream-image, because their names are given to it; but sometimes they certainly are; so that a man who, on looking into water, happens not to see his reflection may believe that his spirit has gone away, and that he himself must be ill, and accordingly he becomes ill; or if at noon near the equator he notices that he has no shadow, he may think his soul is gone, and run to a medicine-man to get it back; and dead bodies may be believed to have no shadows.[179] Inasmuch as a body even lying on the ground casts a shadow, except at tropical noon, the belief that it does not do so at any time implies an acquired inability to see what is before one’s eyes; as sometimes happens in hypnosis and other conditions of negative hallucination.