Boris Alexandrovich Focht - a well-known at the beginning of the 20th century, and now almost forgotten Russian neo-Kantian philosopher of the Marburg school, translator of philosophical classics, propagandist of the ideas of criticism and rationalism. He is the author of works on the history of ancient Greek philosophy, on the problems of German philosophy, logic and aesthetics. This book is the first to publish the works of B.A. Focht of the 1920s, devoted to the history and theory of Marburg neo-Kantianism.