English summary: In this two-volume work, Karl Popper deals mainly with the development of historicism, which is the idea there are laws of historical development that describe the stages we must pass through, as it is found in the works of Plato (Volume I) and of Hegel, Marx and their successors (Volume II). In addition, it contains a wide variety of discussions about epistemological, philosophical, ethical and political questions which are of continuing relevance. The fact that this book has been translated into 23 languages since 1945 demonstrates that Popper's 'war effort' is much more...