“Every concept is necessarily and essentially inscribed in a chain or a system, within which it refers to another and to other concepts, by the systematic play of differences.  Such a play, then—difference—is no longer simply a concept, but the possibility of conceptuality, of the conceptual system and process in general.  […] Within a language, within the system of language, there are only differences.  A taxonomic operation can accordingly undertake its systematic, statistical, and classificatory inventory.”

—Jacques Derrida, “Differance”

The major move of deconstruction is to interrogate binary oppositions in Western thought (good/evil, man/woman, black/white, right/wrong, and so on) to determine how certain ideas have gained credence over others (by social construction).  Derrida deals with signification and the inability of the sign to signify the referent because of the constant chain of deferred meaning—that is to say, the constant slippage between articulations or representations of the thing and the thing as it exists in the phenomenal world.  Put another way, the slippage is between the production of difference without origin and the actual quality of the referent that precedes thought and articulation.  Derrida gives this slippage the name “differance,” a hybrid and invented term that implicates what he elsewhere calls “metaphysics of presence.”

Derrida draws on the dualisms of Western and Platonic philosophy to suggest that all concepts are understood by their inverse.  If all concepts are understood by their inverse, then any understanding of an inverse concept necessarily depends upon another inverse concept.  Every opposing concept is itself intelligible because of additional opposing concepts, and no concept is absolute or transcendental such that it has no inverse; therefore, the search for an origin of meaning reveals that there are only networks of differences, each of which has been produced by humans.  There is no starting or stopping point to this constant deferral of meaning, or what Derrida calls “a chain or system.”  There is, in other words, no pure present.

Meaning, although never present in the sense of being fixed in time and space, resides in whatever taxonomic operation has created and arranged signifiers that humans use to communicate and mobilize.  Language and codes constitute and utilize systems of difference, even if language and codes cannot realize some transcendental signifier.  The most that language and codes can realize is the trace of a presence.  Derrida refers to this strategic realization as, among other things, “protowriting,” an economical exercise that enables humans to convey messages, but that does not bring about an organic unity of meaning.

All positive understanding of words or things comes through negation: the devaluing of one inverse and the privileging of another.  When Derrida says (above) that the play of difference is “no longer a concept,” but the “possibility of conceptuality, of the conceptual system and process in general,” he is hinting at this social constitution of words and their value of exchange.  Even if “there are only differences” in a system of language or meaning, humans still harness certain concepts in the service of certain ends.  Humans are not paralyzed by difference; indeed, difference might even enable human action.  It is the aim of deconstruction—which is in principle a value neutral methodology and not a crusading ideology—to show how humans have dealt with difference and organized around (and because of) certain significations that privilege some concepts (or sets of concepts) over other concepts (or sets of concepts).