In critical theory, a binary opposition (also binary system) is a pair of related terms or concepts that are opposite in meaning. Binary opposition is the system by which, in language and thought, two theoretical opposites are strictly defined and set off against one another. It is the contrast between two mutually exclusive terms, such as on and off, up and down, left and right. Binary opposition is an important concept of structuralism, which sees such distinctions as fundamental to all language and thought. In structuralism, a binary opposition is seen as a fundamental organizer of human philosophy, culture, and language.
Binary opposition originated in Saussurean structuralist theory. According to Ferdinand de Saussure, the binary opposition is the means by which the units of language have value or meaning; each unit is defined in reciprocal determination with another term, as in binary code. It is not a contradictory relation but, a structural, complementary one. Saussure demonstrated that a sign's meaning is derived from its context (syntagmatic dimension) and the group (paradigm) to which it belongs. An example of this is that one cannot conceive of 'good' if we do not understand 'evil'. In post-structuralism, it is seen as one of several influential characteristics or tendencies of Western and Western-derived thought, and that typically, one of the two opposites assumes a role of dominance over the other. The categorization of binary oppositions is "often value-laden and ethnocentric", with an illusory order and superficial meaning. Furthermore, Pieter Fourie discovers that binary oppositions have a deeper or second level of binaries that help to reinforce meaning, for example : Hero and Villain involve secondary binaries: good/bad, handsome/ugly, liked/disliked, and so on.
Theory of binaries in Western thought
A classic example of a binary opposition is the presence-absence dichotomy. In much of Western thought, including structuralism, distinguishing between presence and absence, viewed as polar opposites, is a fundamental element of thought in many cultures. In addition, according to post-structuralist criticisms, presence occupies a position of dominance in Western thought over absence, because absence is traditionally seen as what you get when you take away presence. (Had absence been dominant, presence might have most naturally been seen as what you get when you take away an absence.) 
According to Jacques Derrida, meaning in the West is defined in terms of binary oppositions, “a violent hierarchy” where “one of the two terms governs the other.” Within the white/ black binary opposition in the United States, the African American is defined as a devalued other.
An example of a binary opposition is the male-female dichotomy. A post-structuralist view is that male can be seen, according to traditional Western thought, as dominant over female because male is the presence of a phallus, while the vagina is an absence or loss. John Searle has suggested that the concept of binary oppositions—as taught and practiced by postmodernists and poststructuralist—is specious and lacking in rigor.
Deconstruction of Western binaries
The political (rather than analytic or conceptual) critique of binary oppositions is an important part of third wave feminism, post-colonialism, post-anarchism, and critical race theory, which argue that the perceived binary dichotomy between man/woman, civilized/uncivilised, and white/black have perpetuated and legitimized Western power structures favoring "civilized white men." In the last fifteen years it has become routine for many social and/or historical analyses to address the variables of gender, class, sexuality, race and ethnicity. Within each of these categories there is usually an unequal binary opposition: bourgeoisie/ working class man; white/people of colour; men/women; heterosexual/homosexual.
Post-structural criticism of binary oppositions is not simply the reversal of the opposition, but its deconstruction, which is described as apolitical—that is, not intrinsically favoring one arm of a binary opposition over the other. Deconstruction is the "event" or "moment" at which a binary opposition is thought to contradict itself, and undermine its own authority.
Deconstruction assumes all binary oppositions need to be analyzed and criticized in all their manifestations; the function of both logical and axiological oppositions must be studied in all discourses provide meaning and values. But deconstruction does not only expose how oppositions work and how meaning and values are produced in a nihilistic or cynic position, "thereby preventing any means of intervening in the field effectively". To be effective, and simply as its mode of practice, deconstruction creates new notions or concepts, not to synthesize the terms in opposition, but to mark their difference, undecidability, and eternal interplay.
- Smith, G. (1996). "Binary opposition and sexual power in Paradise Lost". Midwest Quarterly 27 (4): 383.
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- Lacey, N 2000, Narrative and Genre, p.64, Palgrave, New York.
- Lacey, N 2000, Narrative and Genre, p. 65, Palgrave, New York
- Goody 1977, p. 36
- Fourie, Pieter (2001). Media Studies Volume 2: Content, Audiences and Production. Lansdowne: Juta Education.
- Britannica 2011, Binary opposition, viewed 9 March 2011, http://www.britannica.com/EBchecked/topic/65552/binary-opposition
- Derrida, Jacques (1992). Positions. p. 41.
- Hogue, W. (2008). "Radical democracy, African American subjectivity and John Edgar Wideman's Philadelphia Fire". Melus 33 (3): 48. doi:10.1093/melus/33.3.45.
- In 1983, American philosopher John Searle reviewed Johnathan Culler's On Deconstruction: Theory and Criticism after Structuralism for the New York Review of Books, writing,
- "In Culler's book, we get the following examples of knowledge and mastery [attained from analysis of binary opposites and deconstruction]: speech is a form of writing (passim), presence is a certain type of absence (p. 106), the marginal is in fact central (p. 140), the literal is metaphorical (p. 148), truth is a kind of fiction (p. 181), reading is a form of misreading (p. 176), understanding is a form of misunderstanding (p. 176), sanity is a kind of neurosis (p. 160), and man is a form of woman (p. 171). Some readers may feel that such a list generates not so much feelings of mastery as of monotony. There is in deconstructive writing a constant straining of the prose to attain something that sounds profound by giving it the air of a paradox, e.g., "truths are fictions whose fictionality has been forgotten" (p. 181).
- Dunk, T 1997, 'White guys: studies in post-modern domination and difference', Labour, vol. 40, p. 306, (online Infotrac).
- "One sometimes gets the impression that deconstruction is a kind of game that anyone can play. One could, for example, invent a deconstruction of deconstructionism as follows: In the hierarchical opposition, deconstruction/logocentrism (phono-phallo-logocentrism), the privileged term "deconstruction" is in fact subordinate to the devalued term "logocentrism," for, in order to establish the hierarchical superiority of deconstruction, the deconstructionist is forced to attempt to represent its superiority, its axiological primacy, by argument and persuasion, by appealing to the logocentric values he tries to devalue. But his efforts to do this are doomed to failure because of the internal inconsistency in the concept of deconstructionism itself, because of its very self-referential dependence on the authority of a prior logic. By an aporetical Aufhebung, deconstruction deconstructs itself." Searle, ibid.
- Cf., Jacques Derrida, “Positions” (The University of Chicago Press, 1981), pp. 41-43
- Goody, Jack (1977). The Domestication of the Savage Mind. Cambridge: Cambridge University Press. ISBN 978-0-521-29242-9.