Thelema is an English transliteration of the Greek word for "Will". In the modern day its usage has become synonymous with the philosophical, religious and magickal system founded by the poet, mystic, mountaineer and magician Aleister Crowley.

Whilst touring Egypt with his wife in April of 1904 Crowley received a text in three chapters entitled "The Book of the Law". The entity that dictated this text to Crowley, which went by the name of Aiwass, claimed that it spoke on behalf of the forces whose period of governance over the affairs of the world was just commencing. These forces were anthropomorphised in the forms of the ancient Egyptian gods Nuit, Hadit and Horus. It is important to note that although these deity-forms are of paramount importance in the Thelemic cosmology they are not always worshipped in the traditional sense.

The full implications of the information transmitted to Crowley during the three days over which the book was received have been subject to analyses of far greater size than the original text itself. It is not our intent to go into a detailed explanation here, but to provide the visitor with a sufficient understanding of Thelema to place the existence and activity of the OTOF in an appropriate context.

The Book of the Law lays down the ethical system by which all individuals should attempt to govern themselves during the coming two millennia, a period referred to by those who accept the book's classification of historical periods as "The Aeon of Horus". This system can be summarised as follows: