From Amazon
This definitive edition of Frater Achad's
Liber Thirty-one relies heavily on Achad's original manuscript and is annotated with T. Allen Greenfield's explanations of Achad's more obscure references. As a primary source,
Liber Thirty-one offers a glimpse into the psyche of the man best known as
Aleister Crowley's "magical child." Students of Thelema (the system of magic developed by Crowley) will find Achad's work profoundly eye opening, as he reveals the key to Crowley's cryptic
Liber Al vel Legis. The reflective nature of Achad's key is remarkably similar to Zen teachings, but its application to Qabalistic magic is nothing short of art.
--Brian Patterson