Within the archives of the Royal College of Psychiatrists were recently discovered about 80 MD theses on psychiatric topics dating from the 18th century. They are in Latin, come from locations across Europe and must have been specially collected, although unfortunately the donor is not recorded.

I looked more closely at a thesis entitled ‘Dissertatio inauguralis practico-medica de Daemonomania et variis ejus speciebus’ (‘Inaugural medical dissertation on Demonomania and its various subclasses’). The author, Martinus Martini from Saxon Transylvania, presented this at the University of Vienna in 1782. His tone is that of a young man who, while presenting a sensational topic in an apparently challenging way, makes considerable use of earlier sources and expects the approval of at least some of his seniors.

Martini explains that the name ‘Demonomania’ was given to conditions in which ‘a Demon is said to have exercised its force in various ways on men and other animate and inanimate things’. He distinguishes demonomania from other forms of insanity first by their psychopathology:

and also sociologically:

He classifies the condition into three: first ‘True Demonomania’, the existence of which he questions; second ‘Feigned Demonomania’ in which he includes witches, vampires, religious or political fanaticism, and amok due to opium; third, ‘Falsely Ascribed Demonomania’, which includes causes such as worms, hysteria, the ‘Polish Plait’ and ‘cardiac’.

Martini's structure and many of his descriptions are essentially taken from Francois Boissier de Sauvages de Lacroix (1706–1767). The latter was professor of physiology and pathology, and later also of botany, at Montpellier University. He was a friend of Linnaeus, whose classification system Sauvages developed as a pattern for medical diagnosis in his Nosologia Methodica, published in 1763. This classification of 2400 medical diseases was divided into 10 ‘classes’, one of which comprised the bulk of the mental diseases, divided into four ‘orders’ and 23 ‘genera’, one of which was Demonomania. Linnaeus also classified diseases in Genera Morborum (1763) and included Demonomania, which he characterised as a ‘chronic insanity, partial, furious, meticulous and concerning demons’, but does not include vampirism.

In Britain, William Cullen (1710–1790), professor at Edinburgh, disagreed in his Synopsis Nosologia Methodica (1769), remarking that:

This is similar to Martini's grouping although Martini does not reference Cullen.

Cullen's scheme influenced Philippe Pinel, who developed his own classification of what he called mental alienation (Treatise on Insanity, 1806). He did not use the terminology of demonomania except in reference to the belief of religious rituals, which he set largely in the unenlightened past:

Martini himself is entirely sceptical of the supernatural, and offers alternative biological and psychological explanations in some detail, especially in the case of vampirism – but that is another story …