In this book, the author seeks to give not only a fundamental (general) coverage of the topic, but also to trace how the unity of dialectics, logic and epistemology manifests itself in different spheres of human knowledge of the objective world. At the same time, B.M. Kedrov is trying to show (on material from the history of natural science) what great importance dialectical-materialistic methodology is for individual sciences. The book illuminates the unity and relationship of dialectics with the theory of knowledge of materialism.