We have spirit possession when a person assumes a state of apparent auto-hypnosis or dissociation, and his behaviour, which is not that of his ordinary self, is understood to be due to the control by some spiritual agent normally outside him. Possession by a spirit of some kind is often given as an explanation of illness or abnormality, especially in the case of states of mental derangement or dissociation, when the subject does seem to be ‘out of his mind’. The social history of Western Europe provides numerous examples of possession by evil spirits, especially in connection with witchcraft. Since possession is usually a bad thing the question then arises: what is to be done about it?
Different cultures give different answers. Sometimes a spiritual force conceived to be more powerful than the presumed spirit may compel it to leave its victim. Other times techniques of ‘peaceful persuasion’ may be used. A shaman may with soft words, cajole a minor spirit which is troubling a client to leave him and to enter an earthenware pot. The pot is then quickly sealed with clay, and is later destroyed or abandoned in the bush. In other cases, where the subject is not merely possessed but is also a medium, he may, as it were, come to terms with the spirit through the performance of appropriate ritual. Whether the spirit is the ghost of a deceased relative or some other kind of power, it may use its medium, while in a state of induced possession, to say what it requires if it is to leave its victim alone.