Abrahadabra

Abrahadabra is a word coined by Aleister Crowley, who respelled the ancient magical word abracadabra with a d in place of its second c to yield an eleven-lettered form he invested with elaborate significance. In his system of Thelema it is presented as a key word of the new age he proclaimed, the word of the Aeon, its eleven letters and their arrangement read through numerical and symbolic correspondences as expressing the union of opposites, of the human and the divine, the microcosm and the macrocosm, that his teaching sought.

The older abracadabra from which he formed it was a genuine word of ancient magic, written in a diminishing triangular pattern and worn as an amulet against fever, attested in a late-antique medical text. Crowley's reworking is characteristic of his method of taking traditional magical material and recasting it within the framework of his own revealed system, and Abrahadabra holds a central place in Thelemic symbolism.

Abracadabra itself long predates Crowley by many centuries: its first securely dated appearance is in a medical text by the Roman physician Serenus Sammonicus in the second century CE, where it is prescribed as a cure for fever, written repeatedly on an amulet in a shrinking triangular form, one letter removed with each successive line, so the word visually diminishes as the fever it is meant to banish is meant to diminish. Nothing in that ancient use ties the word to the eleven letter significance Crowley later assigned it, and the word's ultimate linguistic origin before Serenus Sammonicus, whether Aramaic, Hebrew or something else, remains genuinely uncertain and is not settled by any surviving source, despite popular folk etymologies asserting one confidently.

Crowley's 1904 respelling in Liber AL vel Legis, changing the second c to a d, is presented within Thelemic doctrine as prescribed directly by the text itself, which states that the word of the Aeon is abrahadabra and identifies the correct spelling as the Word of the Law, distinguishing it explicitly from the older folk magic abracadabra. Thelemic commentary reads the resulting eleven letters as numerologically significant, eleven being treated in Crowley's system as the number of magick, and further analyses the word as encoding a formula of six letters and five letters representing the union of macrocosm and microcosm, an interpretive structure entirely absent from the ancient fever amulet and specific to Crowley's own twentieth century occult system rather than inherited from the word's much older history.