後期ウィトゲンシュタインの真理論

Abstract

In his later thought, Wittgenstein abandoned his earlier truth conditional account of meaning and adopted the one that characterizes meaning as use. On the latter view, unlike the former, the concept of truth is not taken as basic concept for the explanation of the concept of meaning. In such a view, then, contrary to the former, we are entitled to understand truth as characterized in light of meaning. By applying this semantic viewpoint to the conception of truth, we can understand his conversion from his earlier view. In the latter, Wittgenstein regards the problem of truth as the problem of the meaning of a truth predicate. According to Wittgenstein, instances of the primary use (i.e. primary meaning) of the truth predicate "is true" are provided by the instances of the disquotation scheme, " 'p' is true=p". As all we can say about truth is exhausted by these instances of the scheme, we should not look for further underlying nature of truth. Such a view has a certain intimacy with the deflationary theory of truth. The first concern of my paper is to show the detail of this deflationaristic aspect in Wittgenstein's later works. Secondly, I argue that this deflationary view, connected with his claim on normativity concerning with meaning, leads to the internalism about truth, the position which claims that we can consider a statement as true only when we can obtain appropriate evidence(s) /ground(s)/reason(s) for the statement. In this case, truth is regarded as a kind of warranted assertalility, an epistemic concept. So, thirdly, I address a question of how Wittgenstein can distinguish the concept of truth from bare justification, and fourth, I propose Wittgenstein's conception of truth following from the considerations.