Abstract

Twin Earth thought experiments are a standard philosophical tool for those offering, or criticizing, metasemantic theories: theories that attempt explain why referring words have the particular referents they have. The general recipe for Twin Earth thought experiments centrally features the description of a planet and population just like Earth and Earthlings, but with some single crucial differeence. In Hilary Putnam’s original version of the experiment, the difference is that the chemical composition of the stuff that looks and behaves like (our) water is XYZ rather than H2O. Such cases show how variation in the physical environment can induce a corresponding variation in reference. In other versions, variations in the linguistic dispositions of speakers are shown to induce corresponding variations in reference. The extension of the word ‘red’ depends on how the linguistic community is disposed to apply that word, as against ‘purple’ or ‘orange’. Perhaps most interestingly, basic normative terms like ‘ought’ or ‘immoral’ seem to vary in neither of these ways. Even if Earthlings and Normative Twin Earthlings consistently made moral judgments in line with two quite distinct moral theories, they might still be talking about the very same property: moral wrongness. The present paper describes and applies a general metasemantic view that yields plausible claims about all three sorts of cases. The view I will defend—neopragmatism—is a fully generalized version of the sort of local expressivism defended in the past by people like Simon Blackburn and Allan Gibbard. Throughout the paper, a contrast is made with a rival approach to the same phenomena: an appeal to reference magnetism.