Deconstruction involves the close reading of texts in order to demonstrate that any given text has irreconcilably contradictory meanings, rather than being a unified, logical whole. As J. Hillis Miller, the preeminent American deconstructor, has explained in an essay entitled "Stevens' Rock and Criticism as Cure" (1976), "Deconstruction is not a dismantling of the structure of a text, but a demonstration that it has already dismantled itself. Its apparently solid ground is no rock but thin air."
Deconstruction was both created and has been profoundly influenced by the French philosopher on language Jacques Derrida. Derrida, who coined the term deconstruction, argues that in Western culture, people tend to think and express their thoughts in terms of binary oppositions. Something is white but not black, masculine and therefore not feminine, a cause rather than an effect. Other common and mutually exclusive pairs include beginning/end, conscious/unconscious, presence/absence, and speech/writing. Derrida suggests these oppositions are hierarchies in miniature, containing one term that Western culture views as positive or superior and another considered negative or inferior, even if only slightly so. Through deconstruction, Derrida aims to erase the boundary between binary oppositions—and to do so in such a way that the hierarchy implied by the oppositions is thrown into question.
Although its ultimate aim may be to criticize Western logic, deconstruction arose as a response to structuralism and formalism. Structuralists believed that all elements of human culture, including literature, may be understood as parts of a system of signs. Derrida did not believe that structuralists could explain the laws governing human signification and thus provide the key to understanding the form and meaning of everything from an African village to Greek myth to a literary text. He also rejected the structuralist belief that texts have identifiable "centers" of meaning—a belief structuralists shared with formalists.
Formalist critics, such as the New Critics, assume that a work of literature is a freestanding, self-contained object whose meaning can be found in the complex network of relations between its parts (allusions, images, rhythms, sounds, etc.). Deconstructors, by contrast, see works in terms of their undecidability. They reject the formalist view that a work of literary art is demonstrably unified from beginning to end, in one certain way, or that it is organized around a single center that ultimately can be identified. As a result, deconstructors see texts as more radically heterogeneous than do formalists. Formalists ultimately make sense of the ambiguities they find in a given text, arguing that every ambiguity serves a definite, meaningful, and demonstrable literary function. Undecidability, by contrast, is never reduced, let alone mastered. Though a deconstructive reading can reveal the incompatible possibilities generated by the text, it is impossible for the reader to decide among them.

Adapted from The Bedford Glossary of Critical and Literary Terms by Ross Murfin and Supryia M. Ray. Copyright 1998 by Bedford Books.