My impressions: Looks full of highbrow flourishes. Since all we have is this excerpt, the part at the end about "authority of origins" is kinda hilarious and mysterious, since it doesn't follow from the rest.
Except for the mysterious end part, my understanding is he's just illustrating the difference between syntax and semantics. I got this from skimming, which was much easier than a close reading.
The author goes on:
"But suppose that it is a DE-bunker rather than a 'Bunker', and a debunker of the arche (or origin), an archie Debunker such as Nietzche or Jacques Derrida, for instance, who asks the question 'What is the Difference' --- and we cannot even tell from his grammar whether he 'really' wants to know 'what' difference is or is just telling us that we shouldn't even try to find out. Confronted with the question of the difference between grammar and rhetoric, grammar allows us to ask the question, but the sentence by means of which we ask it may deny the very possibility of asking. For what is the use of asking, I ask, when we cannot even authoritatively decide whether a question asks or doesn't ask?"
Tayssir