Thelema forms the core guiding principle for the OAV. Thelema is a philosophy put forth in The Book of Law by Aleister Crowley in 1904. The Book of Law was dictated to Crowley by a being called Aiwass and was described as the Law of the New Aeon.
Initiates read the Book of Law and through meditation and the practice of Magick determine what it means to them individually. It is regarded as forbidden to interpret the book for others. Thelema is generally regarded as a spiritual philosophy that emphasizes personal choice and personal responsibility.
One of the core concepts of Thelema is that each man or woman has a divine Will which they work to discover and accomplish. Thelema as a basis for ethical behavior is based on performing one's Will while not infringing upon anyone's right to do their Will. This is a sharp contrast to religions in which ethical behavior is defined by a series of rules and dogmas.
Generally, the Law of Thelema is summarized in the phrases:
Do What Thou Wilt Shall Be the Whole of the LawLove is the Law, Love Under Will