[Carl Friedrich von Weizsäcker: nuclear disarmament and the search for freedom].

Carl Friedrich von Weizsäcker's comprehensive contributions to nuclear disarmament and arms control, as well as his peace policy impulses are to be understood primarily in the context of his family origin, his comprehensive thinking and the historical circumstances of the emerging nuclear age. They have a scientific, political and a strong philosophical-moral component. Beside the factual problems (nuclear energy, military strategy) he was interested in political power issues and their ambivalence and perception. His actual work is not only based on general academic knowledge, but also serve the immediate political influence on a scientific basis. Weizsäcker was not committed to nuclear disarmament or arms control per se, but about creating a lasting peace policy in the nuclear age. The paper discusses in chronological order of Weizsäcker's work within the policy field peace and disarmament. Family origin, study and work on the nuclear programme by Nazi-Germany laid the foundations for his later career. As a young physicist, he was directly involved in the political and ethical dilemma of the military and civilian use of nuclear energy. After the war, in Göttingen and Hamburg the reflections of the Nazi phase and the discussion of ways out of the dangers of the Cold War followed. The Max-Planck Institute in Starnberg dealt with the science-based treatment of global world problems, including the dangers of nuclear proliferation. Finally, Weizsäcker initiated a Peace Council in 1985. He urged both the perception of the moral responsibility of scientists as well as an ethics of the scientific-technological age. According to him, a general and profound change in the consciousness of humankind is needed to solve the existing power problems and the problem of war.