[Demonology in old medical manuscripts]

Demonology, i.e. the faith in the existence of mental diseases caused by demons was a medical problem from the 16th to the beginning of the 18th century. Two types of mental diseases were differentiated: those caused by natural causes and those caused by demonic obsession with attempts of clinical differentiation of the two groups. Among obsessions most frequently hallucinatory and hallucinotic mental diseases were included (in particular with demonic contents), mental disorders with a queer, unusual and antisocial behaviour, conditions of extreme unrest, vomiting of queer things, prediction of the future, "talking foreign languages" the subjects had not learned etc. The way to overcome demonological prejudices was an attempt to clear the obsessed of guilt, to prove that they are the victims of the devil whom they are unable to fight because of their impaired fantasy and because the devil is found of melancholic juice. Therefore gradually the idea was enforced that the obsessed should receive somatic treatment (in addition to magic and liturgical) which rids the obsessed of black bile. Demonology and witchcraft (which was revived during the renaissance along with demonology) are two different phenomena (witchcraft was a social phenomenon) which were frequently confounded or considered identical. This is why some mentally ill people were summoned in court and tried as sorcerers and witches.