Volume 16

Astral Magic and Adelard of Bath’s Liber Prestigiorum; or Why Werewolves Change at the Full Moon

Patricia Aakhus*

Abstract

Astral magic, the capturing of celestial spirits or rays in engraved stones at astronomically propitious times, enters the West with Adelard of Bath’s 12th century translation of Thabit ibn Qurra’s treatise on talismanic magic, Liber Prestigiorum. Derived from Greek, Babylonian, Sabian, Egyptian and Neo-Platonic magical theory and practice, astral magic requires profound knowledge of astronomy. Talismans draw down planetary spirits along stellar rays, the vehicles of transmission, following sympathetic correspondences between astronomical and terrestrial phenomena. In the 12th century works Guillaume de Palerne and Le Chevalier au Lion, magic rings and werewolves are tied to astral magic. These works were written for the English court that supported Adelard, and Gervase of Tilbury’s Otia Imperialia where ‘in England we have often seen men change into wolves according to the phases of the moon’ and ‘there is no precious stone which may not be consecrated for the exercise of its extrinsic power with the herb of the same name or with the blood of the bird or animal, combined with spells’. Adelard’s version of Thabit’s text, along with the Latin Picatrix, also derived from Thabit, had the greatest impact on learned magic in the medieval and early modern periods.

* Patricia Aakhus sadly died during the editing of these proceedings.