Known most widely for his role in the civil rights and peace movements of the 1960s, Abraham Joshua Heschel made major scholarly contributions to the fields of biblical studies, rabbinics, medieval Jewish philosophy, Hasidism, and mysticism. Yet his most ambitious scholarly achievement, his three-volume study of Rabbinic Judaism, is only now appearing in English. Heschel's great insight is that the world of rabbinic thought can be divided into...