The problem of intentional identity, as originally offered by Peter Geach, says that there can be an anaphoric link between an indefinite term and a pronoun across a sentential boundary and across propositional attitude contexts, where the actual existence of an individual for the indefinite term is not presupposed. In this paper, a semantic resolution to this elusive puzzle is suggested, based on a new quantified intensional logic and game-theoretic semantics (GTS) of imperfect information. This constellation leads to an expressive (...) intensional language with a property of informational independence, argued to produce a purely semantic explication to intentional identity statements. One consequence is that various extra-logical and pragmatic factors become of secondary concern; it is possible to solve the puzzle by logico-semantic methods, albeit somewhat radically renewed ones. (shrink)

Even after yet another grand conjecture has been proved or refuted, any omniscience principle that had trivially settled this question is just as little acceptable as before. The significance of the constructive enterprise is therefore not affected by any gain of knowledge. In particular, there is no need to adapt weak counterexamples to mathematical progress.

The truth-conditional theory of sense holds that a theory of truth for a natural language can serve as a theory of sense: if knowledge of a theory of truth for a language L is sufficient for understanding utterance of L-sentences, the T-sentences of the theory 'show' the sense of the uttered object-language sentences. In this paper I aim to show that indexicals create a serious problem for this prima facie attractive theoretical option. The so-called 'instantiation problem' is that a truth-theory (...) for indexical languages needs to contain universal statements that show how the reference of indexicals depends on features of the utterance context. Now one can deduce from such statements T-sentences that do not show the sense of an indexical sentence on an occasion of use. I survey proposed solutions to the instantiation problem by Evans and Sainsbury and, unfortunately, find them all wanting. Perhaps there is nothing like the sense-giving truth-condition for an indexical sentence. (shrink)

This papers aims to analyse sentences of a self-referential language containing a truth-predicate by means of a Smullyan-style tableau system. Our analysis covers three variants of Kripke's partial-model semantics (strong and weak Kleene's and supervaluational) and three variants of the revision theory of truth (Belnap's, Gupta's and Herzberger's).

This paper rebuts criticisms by Hintikka of the author's account of game-theoretic semantics for classical logic. At issue are (i) the role of the axiom of choice in proving the equivalence of the game-theoretic account with the standard truth-theoretic account; (ii) the alleged need for quantification over strategies when providing a game-theoretic semantics; and (iii) the role of Tarski's Convention T. As a result of the ideas marshalled in response to Hintikka, the author puts forward a new conjecture concerning the (...) relationship among truth, meaning and translation. (shrink)

Wittgenstein's later rejection of the externalist Tractarian picture of logic according to which all rationally analysable discourse is properly understood as truth-functional rules out any conception of logic as the study of universal features of discourse. Given later references to 'the logic of our language', some conception of logic appears to survive even on Wittgenstein's later view. However, given his rejection of any conception of philosophical theory as explanatory or hypothetical, Wittgenstein seems to be forced into descriptivism. Despite these constraints, (...) I attempt to show that a valuable account of logic consistent with Wittgenstein's critique can be identified. That possibility raises the question: can any conception of formal logic as valuable modulo natural language survive Wittgenstein's later change of heart? Taking Wittgenstein's rejection of Tractarian conceptions seriously, logic is relativised to language-games in general and, perhaps, localised to particular language-games. Looking at logic in this way opens up the possibility of uncovering inferential structures distinct from those which form the traditional logical-epistemological dichotomy. Here I outline a formal logical framework consistent with all of the foregoing points in terms of which analogues of inferential structures (traditional and non-traditional) can be constructed. Taking third-person ascriptions of psychological predicates as a testcase, I try to show that the formal framework (a system of formal dialogue) has a flexibility which augurs well for future logical investigations into linguistic practices without presupposing knowledge of the kinds of inferential structures which such investigations might reveal. Hence, my claim that the system in question represents logic after (the later) Wittgenstein. (shrink)