The most famous work of the "first encyclopedist of the Middle Ages" Isidore, Bishop of Seville (c. 57036 AD. ), is an all-encompassing system of human knowledge, which has become a link between the spiritual world of antiquity and subsequent eras The translation of the first three of the twenty books offered to the reader covers the field of science. which in medieval universities was called the "family of free arts" and is an ancient Latin grammar textbook, Rhetoric, Logic, Arithmetic, Geometry, Theory of Music and Astronomy . For the first time for a Russian-speaking reader, these disciplines are presented as they were seen by teachers and students in the Middle Ages. The author compiled his books on the materials of ancient science, and even more broadly - the entire cultural universe of antiquity, systematizing, classifying it and converting it for educational purposes. The publication is intended for a wide range of readers interested in the spiritual culture of antiquity and the Middle Ages, with articles, notes and signs.