Magic in the Thirteenth Century: Albertus Magnus, Thomas Aquinas and Roger Bacon

Abstract

Having considered the Arabic theories of astral influences and their appropriation in twelfth-century cosmology, we can say that astral dynamics obtained three interpretive levels: aetiological, considering them as causes of generation, corruption, and terrestrial events; semiological, the celestial bodies constituting signs to be interpreted by the astrologer;1 and operational, astral influences harnessed by the magician to control and divert nature. The first two levels occupied a considerable space in the cosmological works of the twelfth century as we saw in the previous chapter. Magic was only subtly present. In many cases, translators of medical, astrological and philosophical texts also translated magic works: Constantine the African translated Qusta ibn Luqa’s book on Physical Ligatures which is concerned with the occult properties of natural things. It formed part of the Pantegni and was diffused as such in the twelfth and thirteenth centuries, leading to its attribution during these centuries to Constantine himself.2 Adelard of Bath and John of Seville produced independent translations of Thabit ibn Qurra’s Treatise on Talismans.3 In Adelard’s Natural Questions we read about the time when he and his nephew approached an old sorcereress to learn natural magic.4 He wore a green cloak and a ring set with an engraved emerald.5