Derrida, from “A Number of Yes”

p 121

For essential reasons, it is always risky to say “the ‘yes,'” to make just another name or word of the adverb ‘yes’, an object about which constative statements might pronounce the truth. Because a yes doesn’t suffer any metalanguage,it engages the “performative” of an originary affirmation and thus is supposed by every utterance about the yes. Indeed—to put it aphoristically—for Michel de Certeau there is no subject of any kind which does not arise from the scene of the yes. (121)

p 130

All ontological or transcendental statements suppose the yes or the Zusage. Thus they can only fail in any attempt to thematize it. And yet, one must—yes—uphold the ontological-transcendental exigency in order to uncover the dimensions of a yes which is neither empirical nor ontic. . . .Presupposed by every proposition, it cannot be confused with the position, thesis or theme of any discourse. It is through and through the fable which, almost [quasiment] before the act and before the logos, remains almost at the beginning: “Par le mot par commence donc ce texte” (Fable, by Ponge) (“A Number of Yes” 130). [“With the word with begins this text.”]

p 130 again:

But the yes never lets itself be reduced to any ultimate simplicity. Here we rediscover the fatality of repetition, and of repetition as an incisive opening. Let us suppose a first yes, the arche-originary yes, which engages, promises and acquiesces before all else. On the one hand, it is originarily, in its very structure, a response. It is firstly second, coming after a demand, a question or another yes. On the other hand, as an engagement or a promise, it must at least bind itself beforehand to a confirmation in a next yes. Yes, to the next, or to the other yes, already there but nonetheless to come. The “I” does not pre-exist this movement, nor does the subject: they are instituted in it. I (“I”) can only say yes (yes-I) by promising to keep the memory of the yes and to confirm it immediately. Promise of memory and memory of promise. This “second” yes is a priori enveloped in the “first.” (130).