Deflationary Theory of Truth - Disquotationalism

Disquotationalism

On the basis of Tarski's semantic conception, W.V.O. Quine developed what eventually came to be called the disquotational theory of truth. Quine interpreted Tarski's theory as essentially deflationary. He accepted Tarski's treatment of sentences as the only truth-bearers. Consequently, Quine suggested that the truth-predicate could only be applied to sentences within individual languages. The basic principle of disquotationalism is that an attribution of truth to a sentence undoes the effects of the quotation marks that have been used to form sentences. Instead of (T) above then, Quine's reformulation would be something like the following "Disquotation Schema":

(DS) Sentence "S" is true if and only if S.

Disquotationalists are able to explain the existence and usefulness of the truth predicate in such contexts of generalization as "John believes everything that Mary says" by asserting, with Quine, that we cannot dispense with the truth predicate in these contexts because the convenient expression of such generalization is precisely the role of the truth predicate in language. In the case of "John believes everything that Mary says", if we try to capture the content of John's beliefs, we would need to form an infinite conjunction such as the following:

If Mary says that lemons are yellow, then lemons are yellow, and if Mary says that lemons are green, then lemons are green, and...

The disquotation schema (DS), allows us to reformulate this as:

If Mary says that lemons are yellow, then the sentence "lemons are yellow" is true, and if Mary says that lemons are green, then the sentence "lemons are green" is true, and...

Since x is equivalent to "x" is true, for the disquotationalist, then the above infinite conjunctions are also equivalent. Consequently, we can form the generalization:

For all sentences "S", if Mary said S, then "S" is true.

Since we could not express this statement without a truth-predicate along the lines of the those defined by deflationary theories, it is the role of the truth predicate in forming such generalizations that characterizes all that needs to be characterized about the concept of truth.