Within the subject of occultism Crowley wrote widely, penning commentaries on the Tarot (The Book of Thoth), yoga (Book Four), the Kabbalah (Sepher Sephiroth), astrology (The General Principles of Astrology), and numerous other subjects. He also wrote a Thelemic "translation" of the Tao Te Ching, based on earlier English translations since he knew little or no Chinese. Like the Golden Dawn mystics before him, Crowley evidently sought to comprehend the entire human religious and mystical experience in a single philosophy. He self-published many of his books, expending the majority of his inheritance to disseminate his views. Many of his fiction works, such as the "Simon Iff" detective stories and Moonchild have not received significant notice outside of occult circles. However his fictional work Diary Of A Drug Fiend has received acclaim from those involved in the field of substance abuse rehabilitation.

Crowley's most grandiose work is The Equinox, a large bi-annual periodical that served as the official organ of the Argenteum Astrum (A∴A∴), and, later, the O.T.O. It was subtitled "The Review of Scientific Illuminism" and remains one of the definitive works on occultism.

Crowley's other major works include:

• The Book of Lies
• The Holy Books of Thelema
• Konx om Pax

He also wrote a short, highly readable introduction to yoga (Eight Lectures on Yoga) and a polemic arguing against George Bernard Shaw's interpretation of the Gospels in his preface to Androcles and the Lion. Crowley's piece was edited by Francis King and published as Crowley on Christ, and shows him at his erudite and witty best.

Crowley had a peculiar sense of humour. In his Book Four he includes a chapter purporting to illuminate the Qabalistic significance of Mother Goose nursery rhymes. In re Humpty Dumpty, for instance, he recommends the occult authority "Ludovicus Carolus" -- better known as Lewis Carroll. In a footnote to the chapter he admits that he had invented the alleged meanings, to show that one can find occult "Truth" in everything.

Many Crowley biographies relate the story of L. Ron Hubbard and Jack Parsons and their attempt to create a "moonchild" (from Crowley's novel of that name). In Crowley's own words, "Apparently Parsons and Hubbard or somebody is producing a moonchild. I get fairly frantic when I contemplate the idiocy of these louts." Clearly the admiration Hubbard had for Crowley was not reciprocated.

More famously still, he baited Christians by naming himself To Mega Therion, or "The Great Beast" of the Book of Revelation.

Crowley was also a published, if minor, poet. He wrote the 1929 Hymn to Pan [1], perhaps his most widely read and anthologised poem. Three pieces by Crowley, "The Quest [2]", "The Neophyte [3]", and "The Rose and the Cross [4]", appear in the 1917 collection The Oxford Book of English Mystical Verse. Crowley's unusual sense of humour is on display in White Stains [5], an 1898 collection of pornographic verse pretended to be "the literary remains of George Archibald Bishop, a neuropath of the Second Empire;" the volume is prefaced with a notice that says that " The Editor hopes that Mental Pathologists, for whose eyes alone this treatise is destined, will spare no precaution to prevent it falling into other hands."