The Magus; or, Celestial Intelligencer, by Francis Barrett, is widely recognized as one of the fi rst infl uential texts concerning ritualistic magic and the occult in the English- speaking world. Originally printed in 1801, The Magus for the fi rst time brought together sections (or complete translations) of many previously rare and diffi cult-to-fi nd texts in a format that was easily accessible. The works collected in The Magus include a previously translated edition of The Heptameron; or, Magical Elements, by the medieval Italian physician Peter de Abano; The Key of Solomon, a book on magic credited to King Solomon; and, most famously, the De occulta philosophia libri tres (Three Books on Occult Philosophy) by the early-sixteenth-century mystic Cornelius Agrippa, along with the Fourth Book on Occult Philosophy, which has been attributed to Agrippa. Although it was originally divided into three books, The Magus is most commonly printed in one single volume.