Solaris is a 1961 Polish science fiction novel by Stanisław Lem. It is about the ultimate inadequacy of communication between human and non-human species.

In probing and examining the oceanic surface of the planet Solaris from a hovering research station the human scientists are, in turn, being studied by the sentient planet itself, which probes for and examines the thoughts of the human beings who are analyzing it. Solaris has the ability to manifest their secret, guilty concerns in human form, for each scientist to personally confront.

Solaris is one of Lem’s philosophic explorations of man’s anthropomorphic limitations. First published in Warsaw in 1961, the 1970 Polish-to-French-to-English translation of Solaris is the best-known of Lem's English-translated works.

extraterrestrial (alien) life on a far-distant planet. Solaris, with whom Terran scientists are attempting communication, is almost completely covered with an ocean that is revealed to be a single, planet-encompassing organism. What appears to be waves on its surface is later revealed to be the equivalent of muscle contractions.

Kris Kelvin arrives aboard the scientific research station hovering (via anti-gravity generators) near the oceanic surface of the planet Solaris. The scientists there have studied the planet and its ocean for many decades, a scientific discipline known as Solaristics, which over the years has degenerated to simply observe and record the complex phenomena that occur upon the surface of the ocean. They've thus far achieved only the formal classification of the phenomena with an elaborate nomenclature — yet do not understand what such activities really mean in a strictly scientific sense. Shortly before psychologist Kelvin's arrival, the crew has exposed the ocean to a more aggressive experimentation with a high-energy X-ray bombardment. Their experimentation give unexpected results and becomes psychologically traumatic for them as individually flawed humans.

The ocean's response to their aggression exposes the deeper, hidden aspects of the personalities of the human scientists — whilst revealing nothing of the ocean’s nature itself. To the extent that the ocean’s actions can be understood, the ocean then seems to test the minds of the scientists by confronting them with their most painful and repressed thoughts and memories. It does this via the materialization of physical human simulacra; Kelvin confronts memories of his dead lover and guilt about her suicide. The torments of the other researchers are alluded to and sound even worse than Kelvin’s personal purgatory.

The ocean’s intelligence experiences and expresses physical phenomena in ways difficult for their limited earth science to explain, emotionally upsetting the scientists and psychologically putting them on tilt. The alien (extraterrestrial) mind of Solaris is so greatly different from the human mind of (objective) consciousness that attempts at inter-species communications are a dismal failure.