This edition presents five books of the treatise “On the Teachings of Hippocrates and Plato” by Galen, an outstanding Roman physician and philosopher of the 2nd–3rd centuries, the creator of a theoretical and practical system that became the basis for the development of medicine and natural science in general until the scientific revolutions of the 17th–3rd centuries. 19th century These works represent a valuable source of information on the history of medicine of the proto-scientific period. The published translations are provided with an extensive introductory article, notes and bibliography, which examine Galen's main ideas from the perspective of interdisciplinary analysis. The work is a typical example of the connection between Galen’s general theoretical, natural philosophical views and his practical activities as a doctor. The published work is a demonstration of excellent mastery of the empirical method and the skills of synthetic thinking, built on the principles of rational medicine. All this allows us to comprehensively comprehend the historical significance of Galen’s works.