Thelema is a magickal philosophy of life based on Will. The individual Will in Thelema is called Had or Hadit. The Way, or the pleroma of infinite potentiality is called Nu or Nuit.
Thelema is unique but also syncretic. Nu and Had correspond with the Tao and Teh of Taoism, Shakti and Shiva of the Hindu Tantras, Shunyata and Bodhicitta of Buddhism, Ain Soph and Kether in the Qabalah. Followers of the philosophy of Thelema may make use of the methods and practices derived from other traditions, including Alchemy, Astrology, Qabalah, Tantra, Tarot, and Yoga.
Thelema was first presented to the world as a philosophy by François Rabelais. In 1904, Aleister Crowley received via magical means a book commonly known as the Book of the Law. This book states that "The word of the Law is Θελημα." (AL.I.39) and is taken by the modern Thelemite as a basis for understanding and manifesting the Will.
Some consider Thelema a religion (see Thelema (religion)) with its own theology, canon and rites.