The article is a review of the publication: Okolovsky P. Stanislav Lem and reason. Philosophical studies. Minsk: Galiafi, 2022. 224 p. The author is a professor at the University of Warsaw, researching the philosophical legacy of Stanislaw Lem. The book is a collection of essays and interviews that reveal Lem's vision of resolving ontological, epistemological and axiological questions. The Russian-speaking reader is offered an analysis of the philosophy of the mature Lem: it is little known and does not fit into the canonical approaches expressing the history of philosophy of the 20th century. This publication makes a significant contribution to Lemology, allowing one to get an idea of the principles and approaches of Lem as a philosopher, and to look at his philosophical heritage against the background of the ancient classics.