Rudolf Otto (1869–1937), well known for his book The Idea of the Holy, and Rudolf Bultmann (1884–1976), even more famous for his hermeneutical programs of demythologization and existential interpretation, had, according to Bultmann himself, “been friends at Breslau.” Although Bultmann admitted in 1969 with incorruptible fairness that “the calling of the systematic theologian Rudolf Otto was a great gain for the theological faculty at Marburg,” he also had to state that “Otto and I grew so far apart that our students, too, were aware of the antithesis between his work and mine.” Already ten years earlier, in his first autobiographical draft of 1959, Bultmann mentioned “tensions with R. Otto, Hermann's successor,” which “led to lively discussions” among the students at Marburg. Those tensions date back at least to the early twenties, as two letters of Bultmann to Karl Barth reveal. In the first letter, written at the end of 1922, Bultmann stigmatizes the notes of Otto to F. Schleiermacher's Reden, Über die Religion, as “totally misleading.” In a letter written in April 1927 Bultmann expresses the hope that the opposition at Marburg to the Swiss theologian Eduard Thurneysen might be overcome “in six months, when Otto will be in India.” Thurneysen belonged to the new movement of so-called Dialectical Theology.