Epistemology of the Closet is considered a foundational work of queer theory. In it, Eve Kosofsky Sedgwick argues that the standard binary interpretation of human sexuality is too simplistic. She further argues that this oversimplification has damaging repercussions throughout Western culture.

Sedgwick uses the example of the words "public" and "private" to demonstrate a binary wherein each quantity's existence relies on the other. Through this example she illustrates the ways that "heterosexual" cannot exist without "homosexual" and "feminine" cannot exist without "masculine." Because of these intrinsic ties, Sedgwick demonstrates that these binaries are unstable and leave large gaps in understanding. She further illustrates this point by discussing how heterosexual male bonding and homosexual male bonding are indistinguishable from each other, except for the ways that the men involved posture their masculinity.

Through these deconstructions of the binary, Sedgwick demonstrates how the idea that some people are simply born with the allegedly deviant trait of homosexuality is a flawed view. Without the confines of the binary to uphold the idea that male–female relationships are fundamentally different from male–male or female–female relationships (which are also fundamentally different from each other), people's personal and erotic identities become much more complicated and less stable.

Sedgwick also argues that these binaries function to implicitly exclude women from discussions of homosexuality. She argues that the word "homosexual" itself has a male-leaning slant to it in cultural usage and that the word "gay," when claimed by women, indicates a separation from their other possible identity as "lesbian."

From this analysis, Sedgwick builds an argument that "the closet" is constructed out of a performance of obligatory "masculinity" (in gay men) in order to counteract the "femininity" of their actions in pursuing other men. These analyses rely on early modern texts that explore homosexual identity.

Analyses of the performance of straightness bridge into analysis of homosexual coding, or the behaviors and presentation choices that allow gay men to identify themselves to each other, while still remaining "in the closet" and appearing heterosexual to heterosexuals.