In
Greek, the
word "
thelema" means variantly "
will" or "to cast a
magick spell". In
modern mysticism it refers to a
religious system created by
Aleister Crowley, and founded on
Liber AL vel Legis aka
The Book of the Law.
The basic belief of the system of Thelema is "Do what thou wilt shall be the whole of the law. Love is the law, love under will." Its techniques include yoga, zazen, and ritual, and its deities include Nuit, Hadit, and Ra-Hoor-Khuit. Practices revolve around communicating with one's Holy Guardian Angel (or Higher Self), and understanding and implementing one's Magick Will.
Thelema is related in its ancestry to the Golden Dawn system. In addition, it is historically connected with Wicca -- Aleister Crowley wrote ritual for Gerald Gardner, and the Wiccan "An it harm none, do what thou wilt" has a pretty obvious source. There are more tenuous historical links between Thelema and Freemasonry. Modern Discordianism, too, has some Thelema in it, thanks to Robert Anton Wilson.