Irena Backus offers the first examination of Leibniz as both scholar and theologian in more than four hundred years, illuminating the relationship between metaphysics and theology in Leibniz's handling of key theological issues of his time: predestination, sacred history, the Eucharist, andefforts for a union between Lutherans and Catholics and between Lutherans and Calvinists.Drawing on a wide range of Leibniz's writings, Backus carefully presents the philosophical points and counterpoints of Leibniz's positions. She shows how Leibniz's essentially Lutheran nonorthodox theology was reconciled with his philosophy and demonstrates that Leibniz was not a typical Lutheran:the solutions he sought to the problems of confessional division were more philosophical than theological, and his view of sacred history was intended to vindicate his theodicy. Leibniz's unique integration of theology into philosophy proved satisfactory neither to theologians nor to manyphilosophers of his time. This study delves into a wealth of previously unexplored material, and includes the first-ever English translation of the Unvorgreiffliches Bedencken. It will be an important contribution to the history of ideas, and to understanding Leibniz's place in the mainstream Protestant theology of histime.