Sir Karl Popper (1902-1994) is one of the most controversial and widely read philosophers of the 20th century. His influence has been enormous in the fields of epistemology, logic, metaphysics, methodology of science, the philosophy of physics and biology, political philosophy, and the social sciences, and his intellectual achievement has stimulated many scholars in a wide range of disciplines. These three volumes of previously unpublished essays, based on lectures given at the congress KARL POPPER 2002 held in Vienna to mark the centenary of Popper's birth, provide an up-to-date examination of many aspects of Popper's life and thought. Volume I discusses a variety of topics in Popper's early intellectual history, and considers also some features of his remarkable influence outside philosophy. The second part of the volume contains papers that from different political perspectives tackle problems raised by Popper's prncipal contribution to political theory, democracy and community, "The Open Society and its Enemies".