Gotthold Ephraim Lessing (1729-81) stands as a key figure in German intellectual history, a bridge joining Luther, Leibniz, and German idealism. Despite his well-recognized importance in the history of thought, Lessing as theologian or philosopher of religion remains an enigmatic figure. Scholars refer to the riddle or mystery of Lessing, a mystery that has proved intractable because of his reticence on the subject of the final conclusions of his intellectual project. Toshimasa Yasukata seeks to unravel this mystery. Based on intensive study of the entire corpus of Lessings philosophical and theological writings as well as the extensive secondary literature, Yasukatas work takes us into the systematic core of Lessings thought. From his penetrating and sophisticated analysis of Lessings developing position on Christianity and reason, there emerges a fresh image of Lessing as a creative modern mind, who is both shaped by and gives shape to the Christian heritage. The first comprehensive study in English of Lessings theological and philosophical thought, this book will appeal to all those interested in the history of modern theology, as well as specialists in the Enlightenment and the German romantic movement.