Commemorating the 100th birthday of one of the most influential philosophers of post-war Germany, Carl Friedrich von Weizsäcker, my contribution wishes to reflect upon his ideas concerning the capacities and responsibilities of philosophy with view to some of the issues raised in the questionnaire. Weizsäcker was deeply involved – morally and technically - in Hitler’s striving for the atomic bomb. After the war he put effort in preventing Germany’s atomic armament and became spokesmen of the German Pugwash initiative. Later he founded the Max-Planck Institute in Starnberg, which became an interdisciplinary hodgepodge of mission oriented research, assessment of the predicament of contemporary world society, and reasoning on fundamental questions. I wish to take the opportunity to reconstruct his positioning of philosophy with view to the challenges of techno-scientific progress, the responsibilities of science, and his understanding of fundamental questions of ‘men and world’. Whether or not this is guiding to fruitful ideas for contemporary discussion I have no idea yet.