This 17^th century treatise on demonology, written by the respected theologian, Catholic priest, and exorcist, Rev. Father Sinistrari, examines a particular class of spirits known as the incubus and succubus. These minor demons crave sex and often attack their victims while they sleep. Though incubus and succubus are considered less dangerous than possessing demons, they can be relentless in pursuit of their desire and grow violent when resisted.

Demoniality advances novel theories about occult biology, claiming demons can reanimate corpses to have sex and impregnate victims with demonic seed to produce offspring who are "tall, hardy, bold and wicked." An expert on witchcraft and sexual sin, Rev. Father Sinistrari included sections on related phenomena, including: bestiality, necrophilia, demonic pacts, witchcraft, witches' marks, devil worship and magical beings such as fauns, centaurs and elves.

Father Sinistrari was a learned Franciscan Friar who used deductive reasoning to examine the characteristics of the spirit world. For example, do demons have mass? He concludes they do, but determines they are porous-allowing for their supernatural feats of passing through objects and appearing from nowhere. He also classified the demonic spirits by their actions, explaining that some seek out corrupt pacts with witches or wizards, while others are parasitic and indiscriminately attack the innocent.

As a primer on demonic behavior, Demonality is extremely detailed. Father Sinistrari was schooled in the sciences of the time, including herbalism, alchemy, elements, humors and the symptoms of witchcraft-even serving as an advisor to the notorious Inquisition. Because of this, he focuses on diagnoses and remedies to expel the pests, using his alchemical knowledge to devise herbal formulas for countering a demon's specific elemental nature. These elaborate herbal recipes are similar to the elixirs found in a magician's g