The Sepher Yetzirah or "Book of Formation," although very short, is probably the most important of the Kabalistic texts. Its secrets were passed on in the Hebrew oral tradition until it was written down in the 2nd century BCE. It lays out the principles of Kabalistic cosmology and the Tree of Life, how humankind (the microcosm) reflects the Divine (the macrocosm). It also sets forth the Hebrew doctrine of Logos--the creation of the world in numbers, letters, and sound, and therefore is a seminal text for all serious magicians. Stenring has made a word-for-word translation from several...