The book by a world-famous philosopher is devoted to the detailed development of a realistic concept of the philosophy of science. The author explores the problems of the objectivity of scientific knowledge, referents of observable and non-observable objects, the structure and dynamics of scientific theories, the problem of truth in science, issues of ethics of science, social dimensions of scientific activity, the relationship between science and technology, science and metaphysics. As part of his position, E. Agazzi analyzes almost all the main problems of modern philosophy of science and gives a detailed critical analysis of various realist and anti-realist concepts. The author formulates a number of original ideas and proposes his own concept of the semantics of empirical theories. The book is intended for specialists in the field of epistemology, logic, philosophy and history of science.