- Nicholas, of Cusa, Cardinal, 1401-1464 (5)
- Klibansky, Raymond, 1905- (3)
- Descartes, René, 1596-1650 (2)
- Senger, Hans Gerhard (2)
- Springmeyer, Heinrich (2)
- Wilpert, Paul, 1906-1967 (2)
- Zekl, Hans Günter (2)
- Aristotle (1)
- Bormann, Karl, 1928- (1)
- Galen (1)
- Gäbe, Lüder, 1927- (1)
- Happ, Winfried, 1954- (1)
- Koch, Josef (1)
- Kraus, Paul, 1904-1944 (1)
- Plato, 427-347 B.C. (1)
- Walzer, Richard, 1900- (1)
- Willelmus, L. Lorimer (1)