For decades, this book served as a basic textbook on logic and scientific method in most American universities and is still in demand (the latter re-release in English was published in 2007). The authors managed to organically combine the syllogistic of Aristotle formalized language of mathematical logic and methodology of knowledge presents them in close connection with the logic. It covers all the standard themes taught in basic courses in logic, and their presentation is more detailed than in the standard textbooks. As a synthetic course of logic and scientific method has no analogue among Russian textbooks.