The town of Safed in the Galilee becomes the center of the greatest flowering of Jewish mysticism in history in the mid-16th century. The key figures: Joseph Karo (codifier of the Shulchan Aruch, the definitive code of Jewish law, also a mystic who received dictation from a celestial mentor), Moses Cordovero (systematic philosopher of Kabbalah), and above all Isaac Luria (the Ari, 1534–1572) — whose Lurianic Kabbalah introduces the concepts of tzimtzum (divine contraction), shevirat hakelim (shattering of the vessels), and tikkun olam (repair of the world through righteous acts). Lurianic Kabbalah reshapes all subsequent Jewish mysticism and its concept of tikkun olam enters modern Jewish social justice vocabulary.