Belief in the existence of Satan has been evidenced throughout the history of the Church by the extraordinary cases of diabolic possession reported from Biblical times through to the present day. This volume presents these cases anew in the light of modern psychiatric study. The author brings to light the teachings of the Church in relation to the attitudes of contemporary medicine. Epileptic attacks, psychoneurosis, hysteria, convulsions and witchcraft are each examined as possible explanations of the symptoms of these cases of presumed diabolical possession. Cases of both true and false possession do exist. In this detailed study, the author makes the distinction very clear.