This book presents a collection of texts by the German philosopher and physicist Carl Friedrich von Weizsäcker (1912-2007), for use in seminars on philosophy, mainly epistemology and the philosophy of physics or foundations of quantum mechanics, but also for courses on German philosophy of the 20th century or the philosophy of science. Most texts appear in English for the first time. Weizsäcker became famous through his works in physics, later becoming well known as a philosopher and an analyst of contemporary culture and politics. He worked intensively on projects for the prevention of nuclear war and for peace in general. – Texts about classical philosophy are included as well as on logic, on the philosophy of biology and on the philosophy of mathematics, on “death� as well as on “power�.