The O.T.O is the first of the Old Aeon orders to accept The Book of the Law, received by Aleister Crowley in 1904 e.v. , with its message of a revolution in human thought, culture and religion based upon a single supreme injunction: the Law of Thelema, which is "Do What thou Wilt". This law is not to be interpreted as a license to indulge every passing whim, but rather as the mandate to discover one's True Will and accomplish it, leaving others to do the same in their own unique ways. "Every man and every woman is a star".

The Law of Thelema can ultimately be fulfilled only through the efforts of each individual. Nevertheless, many worthy aspirants to the Great Work of Thelema have a genuine need for information, guidance, fellowship, or the opportunity to assist their fellow aspirants and serve humanity. Such aspirants will find welcome in the order.

The structure of the O.T.O., like that of Freemasonry and the ancient mystery schools, is based on a staged series of initiations or degrees, most of which are conferred ceremonially. In the Rituals of these degrees, O.T.O. seeks to instruct the individual by allegory and symbol in the profound mysteries of Nature, and thereby to assist each to discover his or her own true Identity.

Every man and woman of full age, free, and of good report, has an indefeasible right to the first three Degrees of O.T.O. These Degrees follow a pattern based on the symbolism of the Chakras and the rising of the Kundalini. They also represent, in dramatic form, the Individual's Path in Eternity. In the higher Degrees, there is instruction in Hermetic Philosophy, Qabalah, Magick and Yoga, all aimed at preparing the Initiate for the revelation and application of one Supreme Secret.

In addition to the official O.T.O. instructions, many of the local O.T.O. Lodges, Oases, and Camps offer supplementary instruction to their members. The particular form of this supplementary instruction depends on the character and capabilities of the particular local body; it may be provided in the form of classes, seminars, study programs, or publications.

O.T.O. is a California charitable corporation and a federally recognized tax-exempt religious entity under IRS section 501c (3). We have proven ourselves to be the genuine O.T.O. of Aleister Crowley, both in the U.S. Federal Courts, and more importantly by our demonstrated success in faithfully promulgating practical Thelemic philosophy through a careful implementation of Aleister Crowley's vision of the mission of the Order.

O.T.O. currently operates in 17 countries worldwide and has approximately 3,000 active members.Within the broad context of Thelema, O.T.O. functions as a fraternal, initiatory, social and educational organization of a religious nature.

Ecclesia Gnostica Catholica (E.G.C.), or the Gnostic Catholic Church, is the ecclesiastical arm of Ordo Templi Orientis (O.T.O.). The E.G.C. is a Thelemic religious environment, dedicated to the advancement of Light, Life, Love, and Liberty through alignment with the Law of Thelema.

The central activity of the E.G.C. is the celebration of the Gnostic Mass, as set forth in Liber XV, composed by Crowley for O.T.O. and E.G.C. in 1913 e.v. Lay membership in E.G.C. is available through baptism and confirmation. Members of O.T.O. in good standing are eligible for clerical ordination in E.G.C. Members of II° and higher (or even I°, in some situations) are eligible for ordination as Deacon, and those who have reached K.E.W. are eligible for ordination as Priest or Priestess. Many O.T.O. local bodies celebrate the Gnostic Mass on a regular basis. In most locations, no formal affiliation is required to attend the Mass.