German theologian. Born in Stettin (now Szczecin), Poland, he studied at the universities of Berlin, Göttingen, and Basel, lectured at Heidelberg (1955–58), then was successively professor of systematic theology at Wuppertal (1958–61), Mainz (1961–68), and Munich (1968– ). Originally a student of philosophy, he came to Christian faith through rational reflection concerning the meaning of human existence and history. In Revelation as History (1960) he voiced a strong protest against irrationalism in theology. This book provides the key to much of his later development, for example, the “from-below” approach to Christology (Jesus—God and Man), the apologetic approach to Christian doctrine (The Apostles’ Creed), the concern to lead theology out of its isolation to meet the substantial challenge of the sciences (Theology and the Philosophy of Science), and the eschatological orientation which earned him the description, “a mysterious figure in the background” of “The Theology of Hope” (Theology and the Kingdom of God). Contending that he is a Christian because he is a modern and rational man, he has set himself the courageous and controversial task of demonstrating the reasonableness of Christian faith in the modern world.