[...] Deconstruction in this, its most rigorous form acts as a constant reminder of the ways in which language deflects or complicates the philosopher's project. Above all, deconstruction works to undo the idea--according to Derrida, the ruling illusion of Western metaphysics--that reason can somehow dispense with language and arrive at a pure, self-authenticating truth or method. Though philosophy strives to efface its textual or 'written' character, the signs of that struggle are there to be read in its blind-spots of metaphor and other rhetorical strategies.

[...] Once alerted to the rhetorical nature of philosophic arguments, the critic is in a strong position to reverse the age-old prejudice against literature as a debased or merely deceptive form of language. It now becomes possible to argue--indeed, impossible to deny--that literary texts are less deluded than the discourse of philosophy, precisely because they implicitly acknowledge and exploit their own rhetorical status. Philosophy comes to seem, in de Man's work, 'an endless reflection on its own destruction at the hands of literature'.

[...] Thus Barthes (drawing on Saussure) refers metaphorically to 'the speaking mass' in a context which purportedly invokes the totality of language, but which appeals even so to actual speakers and their speech as the source of that totality. Barthes may state, as a matter of principle, that language is at once the 'product and the instrument' of speech, that their relationship is always 'dialectical' and not to be reduced to any clear-cut priority. In practice, however, his theorizing leans upon metaphors which implicitly privilege individual speech above the system of meaning that sustains is.

Derrida's line of attack is to pick out such loaded metaphors and show how they work to support a whole powerful structure of presuppositions. [...]

[...] Deconstruction is therefore an activity performed by texts which in the end have to acknowledge their own partial complicity with what they denounce. The most rigorous reading, it follows, is one that holds itself provisionally open to further deconstruction of its own operative concepts.

[...] Nietzsche saw nothing but blindness and multiplied error in the various attempts to arrive at truth through logic or abstract reason. Philosophy had based itself unwittingly on a series of buried metaphors none the less potent and beguiling for their common and commonsense usage. Nietzsche carries out what amounts to a full-scale programme of deconstruction, attacking every last vestige of philosophic truth and certainty. The fundamental 'laws' of Aristotelian logic are held to be expressions of our present inability to think beyond them, rather than possessing an absolute validity. [...]

[...] The end-point of deconstructive thought, as Derrida insists, is to recognize that there is no end to the interrogative play between text and text. Deconstruction can never have the final word because its insights are inevitably couched in a rhetoric which itself lies open to further deconstruction reading. Criticism can only be deluded in its claim to operate (as Eagleton puts it) 'outside the space of the text' on a plane of scientific knowledge. There is no metalanguage.

[...] Deconstruction neither denies nor really affects the commonsense view that language exists to communicate meaning. It suspends that view for its own specific purpose of seeing what happens when the writs of convention no longer run.