"Solaris" is the most famous of Lem's novels. It had been reviewed many times in various countries and in various languages. It belongs – probably as no other Polish literary work – to the core of its genre, to the canon: a novel about contact with aliens cannot be omitted in discussions of world science fiction. Why has "Solaris" achieved this status? Probably because the book not only present the most original vision of the alien world known to science fiction, but in the most interesting and emotional way present the drama of cognition and its entanglement in literature, in telling stories that is so inseparable for human culture.
Lem is both a polymath and a virtuoso storyteller and stylist. Put them together and they add up to a genius... He has been steadily producing fiction that follows the arcs and depths of his learning and a bewildering labyrinth of moods and attitudes. Like his protagonists, loners virtually to a man, his fiction seems at a distance from the daily cares and passions, and conveys the sense of a mind hovering above the boundaries of the human condition: now mordant, now droll, now arcane, now folksy, now skeptical, now haunted and always paradoxical. Yet his imagination is so powerful and pure that no matter what world he creates it is immediately convincing because of its concreteness and plentitude, the intimacy and authority with which it is occupied... read Lem for yourself. He is a major writer, and one of the deep spirits of our age.
Theodore Solotaroff "The New York Times Book Review"