The inspirational source of this text that Crowley called Liber AL vel Legis was a “superior intelligence” (or “Unknown Superiors”) that the Magus claimed...

Crowley was never able or willing to determine whether it was an autonomous entity or his own deeper magical identity in disguise… or a bit of both.
Through the doctrine of Liber AL vel Legis (which will later become the most sacred and accepted modern grimoire, studied by all of the O.T.O. branches), Crowley imported into the vast and dynamic syncretism of the O.T.O. some important aspects of the theurgic tradition of the Hermetic Order of the Golden Dawn, of which he was at one point a high ranking member. Crowley was also able to insert into the O.T.O.
his own formidable restoration work of pre-monotheistic Gnosis as well as a series of very original symbolic creations that were philosophically deflagrating and suitable to become the core elements of a new and integral vision of the world: magical and scientific at the same time.
Based on his own experience of contact with the main occult knowledge current, both Oriental and Western, as well as his vast philosophical and literary culture that was recognised even by his most fierce opponents, Crowley was able to elaborate (or received from his interior Daemon) a theoretical and practical body of instruments for the amplification of consciousness and exploration of the most obscure, secret and remote regions of the mind and the “supermind”. The Magus had put together this new operational Corpus in 1907 under the name of Silver Star or Astrum Argentinum (A∴A∴), the Brotherhood of the Silver Star which will become and still is today (although subdivided) the internal or parallel operational school to all the various initiatic families of the O.T.O. This school is the source that reifies and renews in a stellar sense the precious Rosicrucian heritage of the Golden Dawn and includes doctrines and operational content of the Magick of “Thélema”, along with techniques derived from Gnostic sources (both Alexandrian and Medieval) as well as Tantric, Sufi and Taoist sources.

From such a complex mix of doctrines and techniques, both magical and
psychoanalytical to the extreme, integrating the work of Randolph and the H.B. of Luxor, emerged an comprehensive method of Self-divinisation of Man and Woman that could have been applied o any proper philosophical and scientific system, ancient or modern. We can therefore state that Crowley gave the first impulse to this dynamic integration between the magical-initiatic culture and the Humanistic-scientific culture pursued by the O.T.O. until know, against the odds of the short-sighted mystical and spiritual ghettos that several philosophical and occult movements, inebriated with partialism, were litterally stuck in.

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Crowley called this system the Scientific Illuminism, defining it as the “the method of Science; the aim of Religion” and was able to merge this in the pre-existent tantric-magical syncretism of the Order, thus amplifying the already ambitious level of understanding and adapting its possible applications in the magical dimension as well as in the profane and daily life.
With the addition of Crowley to the O.T.O. and later on, his leadership of the Order in synergic connection with the Astrum Argentinum, the O.T.O. became the definite centre of reactivation of the pre-monotheistic Sacred. This was inherent to the speculative and operational treasures of the Sumerian, Egyptian, Indo-Tantric, Sino-Taoist, Cabalistic, Gnostic and Sufi traditions. These clandestine and secret traditions that were deeply engraved, although unwillingly, in the Judeo-Christian monotheism.
The O.T.O. therefore became the main European (and later on American) diffusion engine with regards to the studies of practical sexual Magick and the Neuro-psychological exploration through the controlled use of psychedelics and
psychoactive substances. Crowley was among the first in Europe to experiment with these substances in connection with his magical practices and he continued to do so throughout his life.