The German language has two words for courageous, tapfer and mutig. Tapfer originally means firm, weighty, important, pointing to the power of being in the upper strata of feudal society. Mutig is derived from Mut, the movement of the soul suggested by the English word “mood.” Thus words like Schwermut, Hochmut, Kleinmut (the heavy, the high, the small “spirit”). Mut is a matter of the “heart,” the personal center. Therefore mutig can be rendered by beherzt (as the French-English “courage” is derived from the French coeur, heart). While Mut has preserved this larger sense, Tapferkeit became more and more the special virtue of the soldier—who ceased to be identical with the knight and the nobleman. It is obvious that the terms Mut and courage directly introduce the ontological question, while Tapferkeit and fortitude in their present meanings are without such connotations. The title of these lectures could not have been “The Fortitude to Be” (Die Tapferkeit zum Sein); it had to read “The Courage to Be” (Der Mut zum Sein). These linguistic remarks reveal the medieval situation with respect to the concept of courage, and with it the tension between the heroic-aristocratic ethics of the early Middle Ages on the one hand and on the other the rational-democratic ethics which are a heritage of the Christian-humanistic tradition and again came to the fore at the end of the Middle Ages. This situation is classically expressed in Thomas Aquinas’ doctrine of courage. Thomas realizes and discusses the duality in the meaning of courage. Courage is strength of mind, capable of conquering whatever threatens the attainment of the highest good. It is united with wisdom, the virtue which represents the unity of the four cardinal virtues (the two others being temperance and justice). A keen analysis could show that the four are not of equal standing. Courage, united with wisdom, includes temperance in relation to oneself as well as justice in relation to others.