Is there any truth in the age-old belief that human beings can be “possessed" by devils? Or has modern knowledge of psychology and the way in which the nervous system works provided an explanation of the phenomenon in purely natural terms? And, if there is anything in it, how can the fake be distinguished from the real? These and similar questions are discussed in this book by Dr Jean Lhermitte, an internationally known neurologist. Stringent scientific standards of investigation have produced over the past hundred years a critical sense that was usually lacking in the past, but as Dr Lhermitte shows in his examination of famous cases that include Sister Jeanne of the Angels at Loudun, the convulsionaries of St Médard and Magdalen of the Cross of Cordova, the problem is fraught with difficulties that cannot just be explained away, although these cases-exhibit clearly defined symptoms. These symptoms of epilepsy, hysteria, mythomania and frenzied eroticism are discussed in detail by Dr Lhermitte together with the psychological structure of lucid possession. Dr Lhermitte also examines the evidence for genuine diabolical possession in the New Testament and the opinions of authorities ranging from St John of the Cross to Sigmund Freud.