The book by the outstanding English thinker John Stuart Mill (1806–1873) is one of the most famous classic works of philosophy. This work, first published in the mid-19th century, examines problems whose solutions are still relevant in our time. These are the logical-semiotic analysis of natural languages, the development of inductive reasoning, and the use of logic for reasoned solutions to problems in the humanities and social sciences. These three problems are directly related to both the representation of knowledge and cognitive studies of the cognitive capabilities of man and his modern partners - computer systems. The reader will not be left indifferent by the general spirit and tone of the book - faith in knowledge, science, the power of its methods, the ability to make a discussion of the methodology of science and its problems fascinating and instructive. It is in this style that each page of the “System of Logic” appears before us. For philosophers, logicians, linguists, specialists in the field of artificial intelligence, as well as anyone interested in problems of logic and epistemology.