For centuries, the ceremonial evocation of spiritual beings has been Magic's darkest corner. Reputed to fulfil the Magician's material desires, evocation has been the topic of the most famous Grimoires -- the Grammars of Magic. From the Sworn Book of Honorius the Magician, to the Greater Key of Solomon and the Goetia; from the Grand Grimoire, to the complete treatise of the Lemegeton, all give direct, yet difficult, directions to the individual desiring to have the 'good life' in the here-and-now. But the simplest of Grimoires, the Heptameron of Peter de Abano, has escaped the attention of modern Ceremonialists. Its simplicity and power in summoning the Aerial Spirits is second to none. This book lays bare the operation of the Heptameron. Its Magical Axioms, extensive Commentaries, copious notes, and personal instructions to the reader -- all gained from Dr Lisiewski's forty-years of study and practice in Ceremonial Magic -- make this a resource that no serious student.