Aleister Crowley, born Edward Alexander Crowley, (12 October 1875 – 1 December 1947; was an English occultist, prolific writer, mystic, hedonist, and sexual revolutionary. He claimed to be a Freemason, but the legitimacy of his claim has been disputed. Other interests and accomplishments were wide-ranging—he was a chess master, mountain climber, poet, painter, astrologer, drug experimenter, and social critic. He is perhaps best known today for his occult writings, especially The Book of the Law, the central sacred text of Thelema.