Derrida offers a new way of seeing the binary system of structuralism, which neatly divides everything into mutually exclusive categories, such as: good/evil, presence/absence, mind/body, spirit/matter, inside/outside, high/low, light/dark, male/female, etc. In each binary relationship, one is privileged over the other and is defined by what the other lacks. Thus, meaning is relational and defined by how it differs from its opposite (Eagleton 84). If man is strong, positive, rational, and present, then woman must necessarily be weak, negative, emotional, and absent. These categories are fixed and privilege one category over the other, implying a sexist, ethnocentric, and rigid hierarchy.
Rather than seeing binaries as separate and opposite forces, Derrida states that each member of the pair is necessary to the other and to the overall structural system they occupy. In examining the male/female binary, Eagleton states, "Man therefore needs this other even as he spurns it, is constrained to give a positive identity to what he regards as no-thing. Not only is his own being parasitically dependent upon the women, and upon the act of excluding and subordinating her, but one reason why such exclusion is necessary is because she may not be quite so other after all. Perhaps she stands as a sign of something in man himself which he needs to repress, expel beyond his own being, relegate to a securely alien region beyond his own definitive limits. Perhaps what is outside is also somehow inside" (115). Each member of the binary pair is defined by and depends on the other. Sometimes they draw closer together and sometimes they repel, expel, and exclude one another. There is a constant striving between each member of the binary pair, a push–pull relationship of constant movement, unsettled tension, and of becoming, rather than being. This is in stark contrast with the simple, static structuralist model with clearly defined boundaries between each member of the pair who belong to a settled and immovable hierarchy.
The relationship between David Dunn and Mr. Glass in M. Night Shyamalan's Unbreakable illustrates the post-structuralist model of binary opposition. Mr. Glass, the arch villain, identifies his opposite in David Dunn, the superhero, and leads Dunn to discover his identity over the course of the movie. In this scene, Mr. Glass explains that he earned his name because he suffers from a rare disease that attacks his bones and makes them as fragile as glass. He is physically weak and has searched all of his life for his opposite in the world—someone who would not only be physically strong, but absolutely unbreakable. In order to find this superman, he bombed buildings, caused plane crashes, engineered mudslides and finally finds his indestructible opposite when David Dunn miraculously walks away unharmed from a large train wreck Mr. Glass masterminded. He tells Dunn, " Your bones don't break, mine do. That's clear. Your cells react to bacteria and viruses differently than mine. You don't get sick, I do. That's also clear. But for some reason, you and I react the exact same way to water. We swallow it too fast, we choke. We get some in our lungs, we drown. However unreal it may seem, we are connected, you and I. We're on the same curve, just on opposite ends." Mr. Glass points out that although they are on opposite ends of the spectrum, they have more similarities than differences, connecting them and making them like two sides of a coin, rather than two separate and opposite members of a pair. The two define and sustain each other. Mr. Glass tried to make sense of his physical weakness by finding someone as extraordinary as himself. In searching for his counterpart, he blew up buildings, derailed trains, and killed thousands of people, defining himself as evil and casting himself in the role of "villain". In finding Dunn, Mr. Glass has affirmed this identity as "villain" and proceeds to tell Dunn who he is. Dunn then defines himself against Mr. Glass and becomes the good member of this binary pair, as he is not only Mr. Glass's physical opposite, but his moral opposite as well. If Mr. Glass is the evil destroyer, then Dunn must be the good protector. Mr. Glass asks Dunn, "Do you know what the scariest thing is? To not know your place in this world, to not know why you're here. Now that we know who you are... I know who I am. I'm not a mistake! It all makes sense, in the comic you know how you can tell who the arch villain is going to be? He's the exact opposite of the hero! And most times they're friends, like you and me. I should've known way back when. You know why David? Because of the kids! They called me Mr. Glass." By the end of the movie, both characters have a clear understanding of who they are and what their purpose is. Each has defined himself against the other. Each is linked to the other, representing the good/evil, strong/weak, hero/anti-hero binaries who must strive against, but remain forever linked to one another.
Eagleton, Terry. Literary Theory: An Introduction. Minneapolis: University of Minnesota Press, 2008.