The Logic and Metaphysics Workshop will meet on March 5th from 4:15-6:15 in room 3309 of the CUNY Graduate Center for a talk by Vera Flocke (NYU).

Title: The Metasemantics of Indefinite Extensibility

Abstract: Indefinite extensibility is the thesis that any domain of quantification can always be expanded. But how is the possibility of expanding domains of quantification reflected in the semantics of quantified sentences? This paper discusses the relevant meta-semantic options within a framework that distinguishes between semantic values and assertoric contents. This choice of a framework is independently motivated, helps received accounts of indefinite extensibility to escape weighty objections and adds to the available metasemantic options. I then argue for a hitherto overlooked view according to which quantified sentences express stable semantic values but variable assertoric contents. Specifically, the semantic value of quantified sentences are sets of possible worlds that are structured by two equivalence relations, one of which models counterfactual necessity and the other one of which models objectivity. Assertoric contents however are ordinary possible worlds propositions. The advantage of this view is that it explains succinctly what’s at issue in the debate between generality-absolutists, who think that quantification over absolutely everything is possible, and generality-relativists. If the box expresses objectivity, this disagreement concerns the Barcan formula, which entails that domains do not grow as one moves to objectively-accessible worlds.

The Logic and Metaphysics Workshop will meet on February 26th from 4:15-6:15 in room 3309 of the CUNY Graduate Center for a talk by Martin Pleitz (Muenster).

Title: A Dynamic Solution to the Liar Paradox

Abstract: The Liar paradox arises when we combine the assumption that a sentence can refer to itself with our naïve notion of truth and apply our unrevised logic. Most current approaches to the Liar paradox focus on revising our notion of truth and logic because nowadays almost everyone is convinced that there are self-referential sentences. I will argue against this conviction. My argument starts from observations about the metaphysics of expressions: A meaningful expression is based in a syntactic expression which in turn is based in a non-semiotic object, and these are pairwise distinct. As all objects of this three-fold ontology exist only relative to contexts, we can import ideas from tense logic about how existence and reference can interact in a contextualist metaphysics. Semantico-metaphysical reasoning then shows that in this dynamic setting, an object can be referred to only after it has started to exist. Hence the self-reference needed in the Liar paradox cannot occur, after all. As this solution is contextualist, it evades the expressibility problems of other proposals.

Please note that Roy Sorensen (Washington University in St. Louis) will be replacing Graham Priest (CUNY) as the speaker on March 12.