Science/Religion
This theme of science overlapping with religion is threaded clearly throughout the novel and can be clearly seen through the interactions of the explorers with the gestalt-intelligence ocean and the thought-homunculi it creates.The novel blurs a lot of genre lines between science fiction and philosophical, nearly religious, ruminations. Even the plot elements do not clearly fit into the science-fiction genre: deceased loved ones being resurrected by an inscrutable, completely alien, unknowable consciousness that is capable of knowing your innermost thoughts and being able to enact cataclysmic atmospheric phenomenon as a means of destroying the explorers—these sound like the realm of the supernatural, even echoing strongly certain Judeo-Christian imagery. The novel posits, albeit indirectly, that science, ultimately is a futile endeavor that creates more questions that it does answers and that sometimes, especially when met with phenomena that are beyond conventional means to answer, faith might just be the more acceptable response.
Exploration and the Human Condition
Solaris is a significant departure from traditional science fiction novels in that although it tackles the theme of exploration most of the the exploration that happens in the novel isn’t like that of Star Trek where they set down on a new planet to understand alien cultures and terrain; most of the exploration happens inside the minds and emotions of the explorers. The only dominant intelligent species on planet Solaris is a vast planet-sized amorphous liquid being who, although clearly intelligent, doesn’t communicate through any means traditionally understood by the human mind and each attempt it make to communicate with the human scientists, via the simulacra it creates, only damages the humans in profound and irreversible ways. Solaris, both the planet and the ocean-being, serve as a mirror through which humanity is able to evaluate itself and really question what it means to be human.
Otherness
In discussing the theme of otherness the novel posits a very interesting thought: perhaps the most alien frontier that humanity must first deal with and ultimately conquer before attempting to communicate with other sentient extra-terrestrial life is the human mind and the motivations that result from it. Traditional science fiction stories have often cast aliens beings as humanoid or possessing some chimerical qualities, but there will always be an element of the familiar to them, because more often than not these aliens are often parallels of humanity albeit with cosmetic and/or cultural departures. In the novel however the alien creature is as far from anything that the human mind might even remotely conceive of as a sentient being, what with the alien creature being akin to a very intelligent body of water whose means of communication is so completely off the human scale of understanding one has trouble defining the parameters of its cognizance. In fact, Solaris’ means of communication involves a frightening amount of retrospection and introspection—often resulting in a complete mental breakdown in the humans that it tries to reach out to.
Identity
Identity is another major theme in the novel and it is discussed through both the explorers that arrive on Solaris as well as through the thought-simulacra that it creates from deeply suppressed fears and memories of these unfortunate explorers via an unexplained process that can only be described as miraculous. The scientists that have made their way to Solaris suddenly find themselves at a crossroads when they are confronted by their ugliest, darkest, most tightly-guarded fears and memories. The result of being forced to confront these ghosts of the past are disastrous, and often fatal. The novel posits that a person’s identity is the result of carefully curated behaviors and socially acceptable responses. When confronted with a situation that shatters that carefully curated veneer suddenly a new question come to the fore: is a man just the sum total of his behaviors or is that a mere illusion created to maintain acceptability?
Isolation
The characters in the novel spend an immense amount of time alone or holed up with their nightmare homunculi. The homunculi, having been created from their fears and regrets, mean that in a manner of speaking the characters are locked away with their “thoughts.” Isolation is necessary as a theme as it is the catalyst that prompts the characters to confront their fears and to ruminate upon other recurring themes in the novel such as identity and being human.
