On the Operation of Daemons (Pseudo-Psellos)

De operatione daemonum · Peri energeias daimonōn dialogos · Timotheus, or On Demons

Byzantine miniature of Michael Psellos — Michael Psellos, to whom On the Operation of Daemons was traditionally attributed, in a Byzantine manuscript miniature.Unknown/Άγνωστος · Public domain · Wikimedia Commons

Attribution: Traditionally attributed to Michael Psellos (1018–c. 1078); now generally considered pseudonymous
Date: Traditionally 11th century; possibly late 13th or early 14th century; English translation 1843
Language: Greek
Manuscripts & printings: Byzantine Greek manuscripts edited by P. Gautier (1980); Marcus Collisson, English translation, Sydney, 1843

On the Operation of Daemons is a Byzantine Greek dialogue in which a character named Timothy questions a Thracian who has travelled widely and learned about demons, partly from a former monk who had lived among the heretical Euchites. It was long attributed to Michael Psellos, the eleventh-century philosopher, statesman and historian who did write genuinely on demonology and on the Chaldean Oracles. In 1980 Paul Gautier argued from its language and content that it is a later work, perhaps of the late thirteenth or early fourteenth century, and the treatise is now usually cited as Pseudo-Psellos. The dialogue describes accusations of orgiastic rites against the Euchites, then sets out a classification of demons into six kinds according to the elements and regions they inhabit, from the fiery and aerial to the subterranean and the light-hating, and discusses whether demons have bodies, how they perceive, how they influence human imagination and how they cause disease and possession. The treatise combines Christian demonology with Neoplatonic ideas about subtle bodies and daemonic hierarchies. Translated into Latin by Marsilio Ficino in the fifteenth century, it became a standard source on the nature of demons for Renaissance writers on magic and witchcraft, including Agrippa and the demonologists. The archive presents Marcus Collisson's English translation published in Sydney in 1843. Richard Greenfield's study of late Byzantine demonology provides context.

What it contains

Dialogue between Timothy and a Thracian traveller
Accusations against the Euchites
Sixfold classification of demons by element and region
Whether demons have bodies and senses
How demons act on imagination, health and possession
Neoplatonic background of the demonology