Triton hinges upon Tritonian society’s novel acceptance. Sexual freedom, the freedom to change one’s body at will, freedom from government influence, freedom from discrimination, and even freedom from one’s own thoughts and desires are all avenues Delany uses to explore the importance of free and open self-expression. The freedom and permissiveness of this world appear liberating and exciting, but for the main character, it is oppressive and confusing. The tension between the narrator and his setting builds throughout the novel, coming to a head as he faces existential crises due to his failure to understand or accurately identify himself. Even after the adaptations and operations he has considered and undertaken, Bron remains uncertain. For him, the guidelines, restrictions, and traditions of his home world offer a comforting veil that disguises such distressing questions, for he is unequipped to handle the critical self-reflection that free self-expression demands. Bron's hesitancy explains Delany chose to employ the phrase “heterotopia” rather than “utopia”. Although his futuristic setting permits unprecedented freedom of expression, its inhabitants must face the questions such lax permissiveness evokes. 

Another common thread interwoven through Triton’s interpersonal and intergalactic conflicts is the theme of fluidity. Across such simple lines as likes and dislikes and extended into complex ideas such as gender and sexuality, the novel argues that the tokens and markers of self-identity are neither concrete nor monolithic. People have a propensity to change and evolve, and as Bron observes, the Tritonians allow themselves to do so with ease. They repeatedly change their gender, adapt to new sexual mores, and inhabit new selves.

Even though Bron worked as a male prostitute servicing both male and female clientele, Mars, his home planet, is only so liberal and promiscuous, and the world of Triton is entirely foreign to him. Though he seems more than set in his ways, Bron’s encounters with liberated Tritonians—his neighbor, Lawrence, an older gay man; the Spike, a liberated, deeply independent woman; Miriamne, a lesbian who spurns his advances—slowly convince him otherwise. He begins to spiral, questioning who he is and why he feels that way, searching for answers that he had never before considered.

Tolerance for the wealth and variety of human experience is the element that backgrounds Delany’s exploration of Triton’s speculative future. With the notable exception of Bron, the characters remain unflappable. Even conversations about sexuality and morality or interactions with those who have changed their gender or adapted their sexual preferences do not shake them. Bron’s lack of tolerance makes life on Triton incredibly difficult, as he struggles to relate with those around him. He cannot comprehend others’ needs because he cannot understand or even begin to imagine what their lives are like. The familiar mores of gender and sexuality are so ingrained in him that he is incapable of adapting his mindset to other avenues of being. At first, Bron is unbothered by his close-mindedness, seeing it as proof that his worldview is accurate, but he soon begins to feel abandoned and isolated, so he strives to be more understanding and aware of others. Ultimately, he struggles unsuccessfully; however, his effort to change for the better and accept the differences in others indicates the novel’s key theme: tolerance and the effort required to achieve it.