Aleister Crowley was a poet, magician, mountaineer, and polemicist, the most famous, or infamous, name in twentieth century occultism. Crowley's greatest legacy is his eclectic occult system: his Magick persists, a potent synthesis of Golden Dawn magic, oriental esoteric techniques, sexual magic, and the all-encompassing Law of Thelema with its two fundamental principles, 'Every man and woman is a star' and the notorious 'Do What Thou Wilt Shall Be the Whole of the Law'.