In the summer semester of 1949, Karl Rahner gave his first main lecture in Innsbruck on "De paenitentia," which he continued and expanded in later years. The topic of penance was part of his original interests. He was able to demonstrate the direct influence of the divine spirit on humans through the generation of insight and remorse, the initiative of God's grace, and at the same time the concrete embodiment that is present in the ecclesiastical-sacramental act. For this reason, Rahner also showed a strong interest in the history of the dogma of the sacrament of penance, to which he contributed numerous studies.