Why Do We Need a Theory of Truth

Abstract

Over the years, the discussions of what the concept of truth is, and of what a theory of truth can do or ought to be, have always been the important in Davidson's philosophy, but they have been so for different reasons and relative to different questions. At the beginning, when the question was asked about what the nature (or the meaning) of meaning is or what a theory of meaning is supposed to do, the concept of truth was fundamental as well as primitive because the Tarski-style theory of truth had to be implemented in order to accomplish Davidson's ingenious design for constructing his theory of meaning. Then, when the question was directly related to the concern with what a theory of truth ought to be or what Tarski's theory of truth amounts to, Davidson argued for that we should reject attempts to provide a ”right” or ”substantial” theory for the concept of truth, or to offer the so-called correct characterization of Tarski's view of truth. Finally, the concept of truth itself became one of Davidson's two main interests (the other one was ”objectivity”), because he was aware that Tarski's style truth definitions or theories didn't really exhaust the content of the concept of truth, and he wanted to answer the question as to whether truth is a goal of inquiry. From a Davidsonian point of view, instead of asking what a theory of meaning is a theory of, it is more appropriate to ask what a theory of meaning is a theory for. It seems as well to ask what a theory of truth is a theory for fits Davidson's philosophy far better than asking what a theory of truth is a theory of. Davidson's theory of meaning is not a theory for defining the general concept of meaning, neither is a theory of truth in Davidsonian style a theory for defining the general concept of truth. The concept of truth is essential and central, but it is not definable and cannot be reduced to other concepts that are simpler, clearer, or more basic. Davidson's arguments show that while correspondence, coherence and pragmatic theories inflate or pump too much unnecessary content into the concept of truth, deflationary theories ignore or underestimate its important role in our understanding of natural language. If, as Davidson claims, ”it is folly to try to define the concept of truth”, either in an explicit or in an implicit way, why do we still need a theory of truth? I want to argue that we may not need any theory of truth on the metaphysical level, but we do need a theory of truth on the linguistic level-that is, the language-involving level on which truth can explicate the concept of meaning, and has intimate connection with belief or other intentional attitudes. This useful theory of truth will be brought out by exploring a theory of truth based on Tarski's style and a theory of rational decision as developed by Ramsey's version of Bayesian decision theory.