Early Chinese works prescribe that during the performance of ancestral rites, the ghosts are to be represented by people known as the personators of the dead who receive the offerings and are supposed to be temporarily possessed by spirits and to be their mouthpieces. Possession by ghosts or other spirits is, in popular esteem, of frequent occurrence in India, China, Japan and Indo-China. It is one of the many factors which have contributed to the ideas of incarnation and deification, that is, that gods can become men and men gods. In Europe the spheres of the human and divine are strictly separated: to pass from one to the other is exceptional: a single incarnation is regarded as an epoch-making event of universal importance. But in Asia the frontiers are not thus rigidly delimitated, nor are God and man thus opposed. The ordinary dead become powers in the spirit world and can bless or injure here: the great dead become deities: in another order of ideas, the dead immediately become reincarnate and reappear on earth: the gods take the shape of men, sometimes for the space of a human life, sometimes for a shorter apparition. Many teachers in India have been revered as partial incarnations of Vishnu and most of the higher clergy in Tibet claim to be Buddhas or Bodhisattvas manifest in the flesh. There is no proof that the doctrine of metempsychosis existed in Eastern Asia independently of Indian influence but the ready acceptance accorded to it was largely due to the prevalent feeling that the worlds of men and spirits are divided by no great gulf. It is quite natural to step into the spirit world and back again into this.