First published in 1913, the book is widely considered to be without equal in occult literature due to its simplicity, clarity, and depth. In his foreword to this Weiser Books edition, first published in 1980, the famed occultist and ceremonial magician Israel Regardie (1907-1985) writes that "a throughgoing comprehension of this smaller work is required" to truly understand Crowley's magnum opus on magick, Magick in Theory and Practice.

The second part of Book Four offers a concise encyclopedia of magical symbolism, the working tools in practical magick. All of the paraphernalia employed in ritual magick are carefully explained in both psychological and mystical terms. The Wand is the human will. Wisdom is the word. The Cup is understanding, the vehicle of grace. The Sword is reason, the analytical faculty. And the Pentacle is the body, the temple of the Holy Ghost, the great storehouse from which the Magician draws. All phenomena are sacraments, writes Crowley.