So, to the end now -- as always, guess work is involved, and this is provisional. I think I get the gist, though the reasoning of the paragraph on page 87, where you were referring
@Metaphysics Undercover I'm still smudgy on.
Starting where I just left off:
"How does difference give itself to be thought?" What does all this mean?
Husserl, according to the previous, makes Derrida believe that he never believed in the achievement of an absolute knowledge as presence nearby to itself -- but Derrida also states that even though this is the case, that even though sense and the sign are not anchored by wanting to say-the-truth, the metaphysics of presence weaves its way through Husserl's project and tries to make the sign, difference, derived from presence.
The indefiniteness of differance appears only by way of the positive infinity previously discussed, the telos of language. And, likewise, the Ideal as infinite differance is only produced in relationship to death (generally speaking) -- where said Ideal is the infinite differance of presence, in the case of my-death.
Comparing the ideality of the positive infinite to the relation between my-death and the Ideal (as infinite differance) makes this realtion between my-death and the Ideal finite, an empirical matter. So once infinite differance appears, it is finite, rather than infinite. Differance is the finitude of life as the essential relation to itself as to its death. "The infinite differance is finite" -- a contradiction, of course, but a contradiction meant to elucidate differance as play between oppositional concepts -- finite:infinite, absence:presence, negation:affirmation.
If differance appears between, outside, or points to a place that is not dominated by these oppositions, by the metaphysics of presence, then the metaphysics of presence is the end of history. Or, perhaps a better way of saying it, it is a closed history whereupon we master it as we master an object. And, furthermore, even "history" has this quality of mastering, of knowledge as a relation to an object, and is the production of the being in presence.
And full presence is meant to go to infinity to where we have absolute presence to itself -- where we achieve absolute knowledge. But this is only possible in an ideal sense. Hence the oppositional categories which "passes over" ((to use a Heideggerian phrase)) differance and the play between. Metaphysics is wanting-to-hear-itself speak (autoaffection). And this voice, being without differance, is both alive and dead.
2nd paragraph, page 88: Seems to me to be speculating on what this outside of a closure would mean, and acknowledges that if we were to encounter such a question it would sound unheard-of, that it would not be either knowledge or not-knowledge, and that it would seem as if we were wanting to say nothing. I believe the reference to "old signs" is the sort of phenomenological etymology that Heidegger practices, but clearly Derrida believes something more must be done in order to escape this closure. It seems to me that this paragraph acknowledges that we must use signs such as "knowledge", "objectivity", "affirmation:negation", "absence:presence", "finite:infinite" because these oppositions structure our very way of thinking. But there is some hope that through differance we can "break free" of these hierarchies.
Since this is the case we don't know when using these old signs if they are used in the metaphysics of presence or in some novel way. We do not know if the classical distinctions which we have inherited are actually true, or if they are a way of suppressing the truth (since they are so totalizing of our way of thinking, but differance shows us that this totalization, to be cryptic about it, is not total).
The concluding paragraphs seem to be wrapping up these conclusions through metaphore, and noting that, yes, we must speak, yes, we are engaging philosophy in the same manner as it has always been engaged, through the opposition of these concepts -- but what Derrida is after is outside of the concepts of intuition and presentation, outside of sense and non-sense. In fact, given what was just said, it would sound like non-sense.
And though Husserl is the foil through which we are able to see this, he, like others in the philosophical tradition, makes a choice and secures the thing itself -- when the thing itself is infinitely deffered and in each deferal there is a difference from it, something which defines it. Therefore, "the look" (present-at-hand) cannot "remain" (itself a sign steeped in the metaphysic of presence).