138 OPENINGS OF WISDOM is considered by leading scholars to be the classic exposition of the kabbalistic system, providing the student with all the concepts and understandings necessary to navigate and find meaning in the Zohar, the teachings of the ARI and other kabbalistic literature. Luzzatto's outstanding kabbalistic work is Kelah (=138) Pithei Hokhmah, a systematic exposition of the Lurianic Kabbalah. There Luzzatto demonstrates the task which he has undertaken in the history of the Kabbalah: to reveal the internal meaning (nimshal) of the paradigms (meshalim) so numerous in the Lurianic writings, to which they tend to give an anthropomorphic coloring. Luzzatto often quotes from the works of Maimonides; in the same spirit he believes that it will be thus possible to get rid of the main cause of error concerning what is divine: materialization (hagshamah). Rejecting an interpretation which would accept the Lurianic descriptions literally (ki-feshuto) and in a materialistic sense, is for Luzzatto also part of the fight he is leading against Shabbateanism. Kelaḥ Pitḥei Ḥokhmah is the perfect illustration of the close connection between logic and Kabbalah in the works of Luzzatto. The very structure of that treatise is built on the gradation rule. Each petaḥ door or chapter - opens with a general principle (kelal), the details or particular aspects of which are then exposed. Before turning to commentary and explaining the themes which are unique to the Lurianic Kabbalah (such as ẓimẓum), Luzzatto innovates by exposing the principle on which his own kabbalistic doctrine is based: divine unity conceived both as the origin and the finality of creation. He uses the distinction rule to delineate with precision the object of Kabbalah, and details what he means by "divine" (Elohut). He thus refines a principle which was already present in the works of his predecessors, such as Menahem Azarya de Fano, while giving a completely novel interpretation of ẓimẓum, the act of contraction or withdrawal of the divine infinity (Ein-Sof) which preceded the emanation of sefirot.