The book, known as "The Logic of Por-Royal," was intended as a textbook guide to logic, but its place in the history of logic proved to be much more significant. The authors of the book created a logical teaching that develops the methodological principles of R. Descartes and B. Pascal. "Logic" is written in a living, accessible language, reflects the spiritual atmosphere of its time. Logical problems are considered in it against the background of philosophical, scientific, religious ideas of the era.