Edward B. Tylor,
Primitive culture, vol. 2 (of 2…
(1871)
“ That the two great effects ascribed to such spiritual influence in obsession and possession, namely, the infliction of ailments and the inspiration of oracles, are not only mixed up together but often run into absolute coincidence, accords with the view that both results are referred to one common cause. Also that the intruding or invading spirit may be either a human soul or may belong to some other class in the spiritual hierarchy, countenances the opinion that the possession-theory is derived from, and indeed modelled on, the ordinary theory of the soul acting on the body. ”
