Crowley's belief system, Thelema, has been described by scholars as a religion,[215] and more specifically as both a new religious movement,[216] and as a "magico-religious doctrine".[217] Although holding The Book of the Law—which was composed in 1904—as its central text, Thelema took shape as a complete system in the years after 1904.[218]
Crowley believed in the objective existence of magic, which he chose to spell as "Magick", which is an archaic spelling of the word.[230] He provided various different definitions of this term over his career.[231] In his book Magick in Theory and Practice, Crowley defined Magick as "the Science and Art of causing change to occur in conformity with Will".[232] He also told his disciple Karl Germer that "Magick is getting into communication with individuals who exist on a higher plane than ours. Mysticism is the raising of oneself to their level."[233] Crowley saw Magick as a third way between religion and science, giving The Equinox the subtitle of The Method of Science; the Aim of Religion.[234] Within that journal, he expressed positive sentiments toward science and the scientific method,[235] and urged magicians to keep detailed records of their magical experiments, having said: "The more scientific the record is, the better."[236] His understanding of magic was also influenced by the work of the anthropologist James Frazer, in particular the belief that magic was a precursor to science in a cultural evolutionary framework.[237] Unlike Frazer, however, Crowley did not see magic as a survival from the past that required eradication, but rather he believed that magic had to be adapted to suit the new age of science.[235] In Crowley's alternative schema, old systems of magic had to decline (per Frazer's framework) so that science and magic could synthesize into magick, which would simultaneously accept the existence of the supernatural and an experimental method.[238] Crowley deliberately adopted an exceptionally broad definition of magick that included almost all forms of technology as magick, adopting an instrumentalist definition of magic, science, and technology.[239]