Thelema (/θəˈliːmə/) is a social or spiritual philosophy derived from Western esotericism. While it is most often regarded as a religion—a new religious movement in particular—it is also referred to as a philosophy, "religious philosophy", "spiritual philosophy", or "religious matrix".
The fundamental principle underlying Thelema, known as the "law of Thelema", is "Do what thou wilt shall be the whole of the Law. Love is the law, love under will." This phrase can be, and usually is, interpreted universally, having moral, mystical, and socio-political implications.
Thelema was developed in the early 1900s by Aleister Crowley, an English writer, mystic, and ceremonial magician. He believed himself to be the prophet of a new age, the Æon of Horus, based upon a spiritual experience that he and his wife, Rose Edith, had in Egypt in 1904. By his account, a possibly non-corporeal or "praeterhuman" being that called itself Aiwass contacted him and dictated a text known as The Book of the Law or Liber AL vel Legis, which outlined the principles of Thelema. An adherent of Thelema is a Thelemite.
The Thelemic pantheon includes a number of deities, primarily a trio adapted from ancient Egyptian religion, who are the three speakers of The Book of the Law: Nuit, Hadit and Ra-Hoor-Khuit. Crowley described these deities as a "literary convenience". The religion is founded upon the idea that the 20th century marked the beginning of the Aeon of Horus, in which a new ethical code would be followed; "Do what thou wilt shall be the whole of the Law". This statement indicates that adherents, who are known as Thelemites, should seek out and follow their own true path in life, known as their True Will. The philosophy also emphasizes the ritual practice of Magick.