The demand for an ethical orientation in banking theory is becoming increasingly clear in light of recent crises. Milena Valeva explores the question of the theoretical support for normative banking practices and reconstructs the deficient normative understanding of German banking theory. Building on this, she provides insights into the meaningful rationality of Islamic banking through a communicatively secured interpretation of Shari'ah. The author proposes a new systematics of ethical banking theory that contributes to the stabilization of practices in the banking sector.