Psychography is the term applied to texts that have been written by disembodied spirits or beings. There are several forms of this, ranging from the spirit taking full motor control of the scribe to simply working from an intuitive influence. It is considered a form of automatic writing, but unique in that the scribe is generally aware of what is being written (as opposed to going into a trance state).
The Book of the Law is an interesting example of psychography, because it seems to exhibit several forms of it. For example, Crowley claims that the text was dictated to him by Aiwass, and he simply wrote what he heard (a perfectly legitimate form of psychography). However, as an example, the diagonal line drawn across sheet 60 (III:47) suggests that some of the writing was also "automatic" or "mechanical". Further, some of the text was intuitively inspired, and not through Crowley—his wife Rose afterwards wrote in her own hand, "The Five Pointed Star, with a Circle in the Middle, & the circle is Red" (I:60). Crowley even had the nerve to edit the divine author, saying of a dictated phrase (the unfragmentary non-atomic fact of my universality, the non-atomic omnipresence of my body), "people will never be able to understand this," (as if everything else in the text was clear!) to which the angel replied "Write this in whiter words. But go forth on," resulting in the final phrase, "the consciousness of the continuity of existence, the omnipresence of my body" (I:26).
Entire chunks of the text were added in later, mostly from Crowley's poetic transcription of the Stele 666 (e.g. III:37-38). There are also numerous corrections and changes made by Crowley and Rose, some at the time of the dictation and some later, mostly in the first and third chapters. Examples include: the tzaddi (I:57) from the original odd scribble, "clerk-house" (III:41) changed from "clerk-ship", and "Coph Nia" (III:72) from the initial "Copha" (later changed by Rose), plus multiple minor changes. A catalog of all these changes can be explored here.
Liber Legis was, at the time, not in the least bit odd for how it was generated. Psychographic texts had been all the rage for decades and continued in popularity through the 1920s. Several 19th c. treatises on the subject were written, perhaps the best known being The Spirits' Book (1861) by Allan Kardec, Practical Occultism [PDF] (1888) by J.J. Morse, and Psychography (1878) by William Stainton Moses. Well-known psychographic texts of the period include Oahspe: A New Bible (1882) by J.B. Newbrough, various works by Alice A. Bailey, Clothed with the Sun (1889) by Anna Kingsford, The Mahatma Letters by Madame Blavatsky, and A Vision (1925) by W. B. Yeats. A large list of online psychographic texts can be found here.
The practice of channeling messages from higher beings never really stopped, but had a revival in the latter half of the 20th century (who here over the age of 30 doesn't remember "Seth"?). It continues today, now more than ever. With the advent of blogs, psychographers can publish their divine messages as fast as they receive them, and there seems to be a wide audience hungry for it.
Naturally there are a wide range of attitudes regarding psychography, from unquestioning faith to curious skepticism to outright denial. A common explanation of psychography states that it is a product of the unconscious mind, that nothing written using this method can surpass what is already known by the author. It is not uncommon to hear this psychological perspective applied to Liber Legis as well.
From my own point of view, it seems obvious that AL was a product of Crowley's own mind (as are all psychographic texts). Multiple influences were involved in its writing (occult and literary knowledge, memories, attitudes, desires, wounds, etc.), which lends to its complexity and sense of depth. From a psychological frame, as an example, it's possible to interpret AL as Crowley's unconscious attempt to create a new family for himself to replace the cold and harsh one he grew up with. His new mother, Nuit, was—unlike the corporeal version—infinitely warm, loving, embracing, accepting, and sexual. His new father was more like his actual one—stern, merciless, strong, mysterious, and pious (even speaking pseudo-Biblical quotes)—but transformed into a joyful being, approving of his son's hedonistic appetites, as well as being immortal (his father died when he was 12). And then there is the god-child Ra-Hoor-Khuit. Into this divine character Crowley poured all his childish rage against the world, his desperate craving for power and control, and his desire to be respected and worshiped. The entire book is filled with messages giving himself praise, absolution, and authority, as well as permission to be cold and rejecting of others (just as his parents had treated him). From this one perspective, AL can be seen as a narcissistic fantasy—"Lift up thyself! for there is none like unto thee among men or among Gods! Lift up thyself, o my prophet, thy stature shall surpass the stars. They shall worship thy name..." (AL II:78). AL is notable in that most "inspired" texts do not go to nearly such lengths to aggrandize the scribe.
Of course, such an explanation has little import to one who sees value in any given psychographic text. Even those who admit that the product was likely a result of unconscious processes will often say that that doesn't matter, that what's important is the product itself, not the source. "So what if Aiwass was just a projection of Crowley's unconscious? That doesn't mean it has no value!" Too true, I fully admit. In such a case, Liber Legis can be thought of as art. It is certainly true that some pieces of art—whether visual, literary, or auditory—can have a profound spiritual impact on people, providing meaningful inspiration and guidance. But as in all cases with art, it is deeply subjective, even when it draws upon universal human themes. The spiritual spark does not reside within the work itself, but in the relational process between the work and the individual.
And what about the notion that AL isn't of purely psychological origin? This suggests that it is possible to receive divine messages from non-human intelligences and that such a message would have great universal import. Okay, fine; nearly every religion makes some version of this claim. But why should I accept AL on these terms, and not any of the other hundreds of psychographic texts? What tells me that the message of Aiwass is more reflective of reality than that of Seth or Ashtar or Metatron? Why should I not conclude that accepting this notion isn't simply superstition? In the end, I cannot accept that The Book of the Law is of supernatural origin, no more than I can of the Bible or Oahspe.
I certainly accept that AL is a work of art capable of providing meaningful inspiration and guidance—how could I not, since it was so for many years. Since it is my task as a Thelemite (perhaps I could adopt the term Thelemian to differentiate myself from adherents of AL and Crowley) to increase my awareness of Will as well as my ability to carry it out, then it follows that I should be able to employ any text that assists me in that goal. Ideally, I should be able to write my own Book that is applicable to me alone, an articulation of the Law that is my ever-emerging genuine self.
Perhaps that is all these psychographic works really are...folks laying out their own personal truths in the guise of divine inspiration. Of course, if we are each divine beings, then perhaps it's true that "All words are sacred and all prophets true; save only that they understand a little" (I:56). In Crowley's day, there were certainly many "prophets" to choose from. It's also true that not all their works are equal—some have a greater impact than others (although why this might be so is a matter for another essay).
As with nearly all aspects of Crowley's spiritual career, where he tried his hand in nearly everything that was popular in occult circles, he naturally also tried out psychography. It's interesting that his initial assessment was almost dismissive ("This MS...is a highly interesting example of genuine automatic writing. Though I am in no way responsible for any of these documents, except the verse translations of the stele inscription, I publish them among my works, because I believe that their intelligent study may be interesting and helpful."). It wasn't until years later that he considered AL important—curious to think what his legacy would've been like if he hadn't or if the document had remained lost. Still, we have it today, a "highly interesting example of genuine automatic writing" that certainly stands out among the stable of psychographic works of his day.