The author of the book, one of the creators of quantum mechanics, Nobel Prize laureate in physics (1933), draws attention to the need to study the scientific thought of the ancient Greeks, which forms the foundation of modern scientific knowledge and has the integrity that the latter lacks. The author talks about the crisis in which the scientific picture of the world finds itself, about the enormous influence of quantum mechanics on a person’s understanding of the world around him. The book is addressed to a wide range of readers interested in the history and global problems of science.