What is it that led Ernst Troeltsch, who for a time belonged to Albrecht Ritschl's school, to break from the professor he so admired? On the one hand, Troeltsch found fault with Ritschl's historiography of early Lutheran theology. Where Ritschl saw Melanchthon as someone who had distorted Luther's original reformatory insights, Troeltsch praised Melanchton for having clarified and systematized Luther's thought. Troeltsch's critique of Ritschl's historiography is as closely connected to Troeltsch's own theological program as was Ritschl's interpretation of the development of early Lutheran theology to his (Ritschl's) own theological intention. The second half of the article examines Troeltsch's program by looking at the debate between Troeltsch and Julius Kaftan, a prominent Ritschlian in those years, on the supernatural basis of Christianity, the place and scope of metaphysics in theology, and the “absoluteness” of Christianity.