Moses ben Jacob Cordovero, the Jewish legalist and mystic, was the outstanding systematizer of the kabbalah. The place of his birth is not known; his father probably was among the Jews expelled from Cordova, Spain. Cordovero's career centers in Safad, the little town in Palestine that had a period of glory in the sixteenth century. Here, after studying with three distinguished rabbinical teachers—Joseph Caro, Jacob Berab, and Moses di Trani—he was ordained at an early age and became one of the leading figures of the community. His kabbalistic studies were begun at the age of twenty, under the direction of his brother-in-law, Solomon Alkabez, and became the major concern of the remainder of his life. Isaac Luria, who was to become the key figure in a new, more theosophic version of kabbalistic teachings, was originally a pupil of...