The Great Secret completes a trilogy of books by Eliphas Levi published in his "Studies in Hermetic Tradition" series, the two previous volumes being The Book of Splendours and The Mysteries of the Qabalah. Taken together these writings represent a fitting memorial to one who "has been both the keeper of the hermetic tradition and the absolute renovator of esoteric thinking in Europe in the 19th century".

"You will be as gods, knowing good and evil".

So concludes what Eliphas Levi considered to be his last testament, his most important and final treatise, and a summation of his esoteric philosophy. This volume is the conclusion of the work he started with Book One, The Hieratic Mystery or the Traditional Documents of High Initiation, published as The Book of Splendours (Weiser, 1984). The Great Secret contains his final two works: Book Two, The Royal Mystery or Art of Subduing the Powers, in which Levi discusses such topics as Evil, the Outer Darkness, the Great Secret, Magical Sacrifice, Evocations, the Arcana of Solomon's Ring, and the Terrible Secret. Book Three, The Sacerdotal Mystery or the Art of Being Served by Spirits, covers Aberrant Forces, the Chaining of the Devil, Sacred and Accursed Rites, Divination, Dark Intelligence, and the Great Arcanum.