Two-dimensional (2D) semantics is a formal framework that is used to characterize the meaning of certain linguistic expressions and the entailment relations among sentences containing them. 2D semantics has also been applied to thought contents. In contrast with standard possible worlds semantics, 2D semantics assigns extensions and truth-values to expressions relative to two possible world parameters, rather than just one. So a 2D semantic framework provides finer-grained semantic values than those available within standard possible world semantics, while using the same (...) basic model-theoretic resources. The 2D framework itself is just a formal tool. To develop a semantic theory for someone’s language, a proponent of 2D semantics must do three things: (i) explain what exactly the two possible world parameters represent, (ii) explain the rules for assigning 2D semantic values to a person’s words and sentences, and (iii) explain how 2D semantic values help in understanding the meanings of the person’s words and sentences. (shrink)

It is a core commitment of Epistemic Two-Dimensionalism that an utterance is 1-necessary iff it is a priori. But Jeff Speaks's Argument from Misclassification proves that, on a natural interpretation, E2D assigns necessary 1-intensions to many utterances that speakers deem a posteriori. Given that 1-intensions are meant to formalize a speaker's own understanding of the words she utters, this proof raises serious difficulties for E2D. In response, Elliott, McQueen, and Weber point out that the Argument from Misclassification presupposes a controversial (...) theory of reference-fixation for proper names and argue that E2Dists ought to reject this theory. They discuss three alternatives to the theory that render E2D immune to the Argument from Misclassification. I demonstrate here that each of these alternatives either replicates the faults of the original theory by assigning necessary 1-intensions to a posteriori utterances, or makes 1-intensions creatures of darkness. I argue that, although the A.. (shrink)

This note argues that Laura Schroeter's [2005] critique of David Chalmers's epistemic two-dimensional semantics is not touched by a reply by Edward Elliott, Kelvin McQueen, and Clas Weber [2013].

The principle of mass additivity states that the mass of a composite object is the sum of the masses of its elementary components. Mass additivity is true in Newtonian mechanics but false in special relativity. Physicists have explained why mass additivity is true in Newtonian mechanics by reducing it to Newton’s microphysical laws. This reductive explanation does not fit well with deducibility theories of reductive explanation such as the modern Nagelian theory of reduction, and the a priori entailment theory of (...) reduction that is prominent in the philosophy of mind. Nonetheless, I argue that a reconstruction of the explanation that incorporates distinctively philosophical concepts in fact fits both theories. I discuss the implications of this result for both theories and for the reductive explanation of consciousness. (shrink)

Some opponents of epistemic two-dimensionalism say that the view should be rejected on the grounds that it misclassifies certain a posteriori claims as a priori. Elliott, McQueen, & Weber [2013] have argued that any argument of this form must fail. I argue that this conclusion is mistaken, and defend my argument [Speaks (2010] against their criticisms.