Rorty defends his claim that we need no theory of truth, and his consequent rejection of the entire discipline of epistemology, by appealing to Donald Davidsons philosophy of language. Davidson is a philosophical descendent of Quine, and thus, he bears some of the imprint of pragmatism. Davidson himself abjures the epithet "pragmatist," but Rorty argues that he deserves it nonetheless.
We must begin with Tarskis famous Convention (T):
(T) "S" is true iff S,
where "S" is a variable ranging over sentences. Tarski offered Convention (T) as a constraint on theories of truth: any theory of truth that doesnt entail (T) is surely wrong. Now, think of a theory of truth not as an analysis of the concept of truth or of the meaning of the predicate " is true," but rather, as a full blown theory of some particular language, L. Such a theory will take it upon itself to determine which sentences of L are true. That is, it will entail a "T-Sentence" that instantiates (T) for each sentence of L. So, a theory of truth for the English language should entail, inter alia:
"The cat is on the mat" is true iff the cat is on the mat.
Now, suppose that Jones, who speaks English, is developing a theory of truth for German. If her theory is correct, it must entail this T-Sentence for German:
"Der Apfel ist rot" is true iff the apple is red.
A complete theory of this sort would be pretty impressive.
In fact -- and here is a basic Davidsonic insight, or claim, depending on how sympathetic you are to his views -- such a complete truth-theory for German would seem very much like a translation manual for that language. It would tell Jones just when every German sentence is true; it would correlate German sentences with states of affairs that Jones can recognize by way of her own linguistic capacities. Davidson suggests that if we are "field linguists," such a truth-theory as just described is all we can have. A "field linguist" is someone whom we suppose has gone into a community of speakers of a language under study. This linguist has no antecedent knowledge of this language. Davidson labels this enterprise "radical interpretation." The field linguist cannot describe the "inner experiences" of speakers of L, nor tell us antecedently what the significance of their behavior is. All the field linguist can do is correlate the linguistic behavior of speakers of L with situations experienceable by them in the world around them. And these situations would be, of course, characterized in the linguists own language.
Davidson develops his philosophy of language in two ways that Rorty seizes upon. First, such a truth-theory is exhausted by the T-Sentences it entails and does not offer us anything that might be called an "analysis of the concept of truth." This is Rortys "less is more" theme. And theres more: a truth-theory does involve spelling out how nouns and other referring expressions of L correlate with objects, as well as how predicates correlate with properties or classes of objects. (It must do that, because language is compositional: its sentences are composed of, inter alia, referring expressions and predicates.) But such correlations are (a) merely what Rorty calls "fallout" from the truth-theory, i.e., adjustable instruments for making the truth-theory work, and (b) no more analyzed by the theory than is truth.
Second, Davidson puts this line of thought to dramatic use in his argument in "On the Very Idea of a Conceptual Scheme." He is there concerned with the thought, suggested by Kant and Hegel, and popular now amongst many philosophers and especially social scientists (anthropologists come in for especially rough treatment by Davidsonians), that different communities "see the world through different lenses," that they experience the world mediated by different conceptual schemes. A conceptual scheme is a network of concepts that interprets experience, or the world, for us. Davidson wants to argue that the very idea of a conceptual scheme is confused: there cannot be divergent conceptual schemes, and thus, the concept has no utility to us, or the field linguist.
Furthermore, it follows from the conclusion that to the extent that we and the speakers of L differ, one of us is wrong. (This is the Davidsonic rejection of relativism.)
Davidson's "Truth and Meaning" (1967) and "On the Very Idea of a Conceptual Scheme" (1974), are both collected in his Inquiries into Truth and Interpretation (Oxford, 1984).