Demoniality is a Latin theological work by Ludovico Maria Sinistrari, the Italian Franciscan friar and Catholic theologian who lived from 1622 to 1701. The original Latin work was De Daemonialitate et Incubis et Succubis and was written during the late seventeenth century, although it remained unpublished until a manuscript was discovered in London in the late nineteenth century and was published in 1875 in a bilingual Latin French edition by Isidore Liseux.
Sinistrari was a substantial figure in late seventeenth century Italian Catholic theology and canon law. He served as a consultor to the Roman Inquisition and produced substantial works on canon law, on the practical questions of inquisitorial procedure, and on various theological subjects. His best known work during his lifetime was De Delictis et Poenis, a substantial treatise on crimes and punishments under canon law that was widely used in Italian ecclesiastical legal practice for several generations after his death.
Demoniality addresses the theological and canon legal status of sexual relations between human beings and demonic beings, particularly the incubi and succubi of late medieval and early modern European demonological tradition. The subject had a long history in European Christian theology going back to the early Church Fathers, with substantial scholastic theological literature on the question developing in the medieval and early modern periods. The general theological position by the early modern period was that demons could not produce true sexual relations with humans in the natural sense but that various forms of demonic deception and assault were nonetheless theologically and legally significant.
Sinistrari’s particular contribution to the discussion was a substantially original position. He argued that incubi and succubi were not actually demons in the strict theological sense but were instead a separate class of intelligent created beings, intermediate between angels and humans, who possessed material bodies of an unusual kind and who were capable of producing actual offspring through their sexual relations with humans. The position was controversial in his own time and was substantially at odds with the dominant theological consensus, which is probably why the work remained unpublished during his lifetime.
The book is of interest now to historians of early modern European demonology, of Catholic theological and canon legal tradition, and of the broader history of European thinking about sex, gender, and supernatural beings. It pairs naturally with the broader early modern demonological literature and with modern academic studies of the field.