The Spirits' Book
Book Two - The Spirit World
Chapter IX - Intervention of Spirits on the Physical World
474. If there is no such thing as possession or the cohabitation of two spirits in the same body, is it possible for one soul to be overpowered by another so that it sees itself “subjugated” or “obsessed” to the point of having its will somehow paralyzed?
“Yes, and it is this domination that constitutes what you call possession. You must understand that this domination is never established without the willing participation of the spirit who subjects to it, either due to its weakness or by its desire. People often have misidentified cases of epilepsy or insanity for possession, when they really need a physician rather than an exorcist.”
The word possession, as popularly understood, presumes the existence and cohabitation of demons, that is, a category of beings of a wicked nature, with a person’s soul in his or her body. Since demons do not exist in the aforementioned sense, and since two spirits cannot simultaneously inhabit the same body, there is no such thing as possession according to the idea normally attached to that word.. You should understand the word possessed defined only as the absolute domination of a soul by an imperfect spirit to whom it has surrendered.