The author's most important and final treatise on the occult sciences and the summation of his esoteric philosophy. It contains two works, The Royal Mysteryor Art of Subduing the Powers,in which he discusses such topics as Evil, The Outer Darkness, The Great Secret, The Arcana of Solomon's Ring, and The Sacerdotal Mystery or the Art of Being Served by Spiritswhere he expounds on the subjects of Aberrant Forces, Divination, Dark Intelligence, and the Great Arcanum.