[...] 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'.

what de Man calls the 'dialectical interplay' set up between text and interpreter

Language is in this sense diacritical, or dependent on a structured economy of differences which allows a relatively small range of linguistic elements to signify a vast repertoire of negotiable meanings

the 'diachronic' methods of historical research and speculation which had dominated nineteenth-century linguistics

[...] 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. [...]

It is not a question, he repeats, of rejecting the entire Saussurian project or denying its historical significance

Difference [...] remains suspended between the two French verbs 'to differ' and 'to defer', both of which contribute to its textual force but neither of which can fully capture its meaning

the harmonic or contrapuntal, which typified the supposed weakness and decadence of French tradition

The deadlocked prolixity of Rousseau's text is also a lesson