Paradigms and Certainty

In short, one might say that Wittgenstein's fundamental critcism of Moore's method was that he was wrong in believing that he could refute the skeptic by elucidating a series of propositions that were indubitable, known, and certain. In doing this Moore misused the word "know," since the way these propositions usually function is as paradigms for propositions which we can be said to know or not to know. Qua paradigms they do not themselves enter (directly) into the "known-is not known" language game. Doubt ends somewhere, and where it ends is not in propositions of which we are certain, or which we know, but in propositions A) which we do not doubt, because B) they do not enter directly into the language-game of doubting and knowing, but rather C) function as yardsticks or standards according to which such language-games are played. (C. G. Luckhardt, "Beyond Knowledge: Paradigms in Wittgenstein's Later Philosophy," p. 248.)