The Ikhwān al-Ṣafāʾ (Brethren of Purity), the anonymous adepts of a tenth-century esoteric fraternity based in Basra and Baghdad, hold an eminent position in the history of science and philosophy in Islam due to the wide reception and assimilation of their monumental enyclopaedia, the Rasāʾil Ikhwān al-Ṣafāʾ (Epistles of the Brethren of Purity). This compendium contains fifty-two epistles offering synoptic accounts of the classical sciences and philosophies of the age; divided into four classificatory parts, it treats themes in mathematics, logic, natural philosophy, psychology, metaphysics, and theology, in addition to didactic fables.This edition of Epistle 52b and 52c On Magic, Part II, complements Epistle 52a. With this volume the epistle 'On Magic' is reconstituted in its complex heterogeneous variations. The Brethren of Purity's treatment of the theoretical and practical aspects of the occult science of magicians and diviners carries some resonances with the prophetic healing arts, the pseudo-Aristotelian corpus, and the Hermetica. It also covers incantations, divinations, astrology, alchemy, necromancy, phantasmagoria, prestidigitation, omens, spells, talismans, and auguries. The Brethren themselves state that 'this epistle of ours "On Magic and Incantations" was written for the Brethren's sake in such a way that, once they have reached the summits of the sciences and the noble arts, they will by [doing] this dispense with the need for anyone but themselves for whichever affair of this mundane existence they would need this.' The present edition is accompanied by comprehensive footnotes and a substantial introduction.