Aleister Crowley (1875-1947) was the most widely read author in 20th-century occultism. He single-handedly redefined magic as a field of inquiry and endeavor through his books and the order that he led--the A.A. and the O.T.O. He is the author several books including The Book of the Law, 777 & Other Qabalistic Writings, and The Book of Thoth. Lon Milo DuQuette has been involved with occult studies since the late 60s, and has become an acknowledged and widely recognized authority within the world of modern occultism. His previous publications include Magick of Thelema, The Tarot of Ceremonial Magick, Angels, Demons & Gods of the New Millennium, and the humorous, biographical My Life with the Spirits.