The conference focuses on the Jewish philosopher of religion Hans Jonas (1903-1993), who studied in Freiburg, Berlin and Marburg and received his doctorate under Martin Heidegger and Rudolf Bultmann. Among his most influential works, which also attract a large international readership, is “The Principle of Responsibility” (1979). It is impossible to imagine Jonas' philosophical career and thinking without the influential time he spent in Marburg in the 1920s. The recently published correspondence between Jonas and his teacher Bultmann, shows that the intellectual friendship between the two philosophers lasted a lifetime. The letters, edited by Andreas Großmann and sponsored by the Hessian State Chancellery, among others, are evidence of a fruitful philosophical-theological dialogue that originated in Marburg. (Rudolf Bultmann-Hans Jonas, Briefwechsel 1928-1976, Mohr Siebeck: Tübingen 2021).