Aleister Crowley, born Edward Alexander Crowley on October 12, 1875, was an English occultist, writer, and ceremonial magician. He is best known for his involvement in various occult and esoteric practices, as well as his writings on the subject. Crowley was a highly controversial figure during his lifetime and remains influential in occult circles to this day. He was a member of several occult organizations, including the Hermetic Order of the Golden Dawn, an influential esoteric group that focused on ritual magic and spiritual development. Throughout his life, Crowley explored and practiced various forms of ritual magic, including ceremonial magic, divination, and alchemy. He developed his own system of magic called Thelema, based on the central principle of “Do what thou wilt shall be the whole of the Law.” Thelema emphasizes individual freedom, self-realization, and the pursuit of one’s true will.