Thoughts on Twin Earth

Abstract

Abstract The questions at issue in this discussion of Hilary Putnam’s Twin Earth thought experiment include the scope and limits of narrow versus wide meaning, the role of attempting to successfully refer as opposed to successfully referring in determining where meaning resides and how thought functions in relation to the meanings of words and sentences. Twin Earth is supposed to challenge the Fregean thesis that intensional sense (Sinn) determines extensional reference (Bedeutung), and that meanings are ‘in the head’. Putnam in ‘The Meaning of “Meaning”’ (1975) concludes emphatically that the Twin Earth thought experiment definitively shows that meanings are not in the head. It is argued here in a previously unexplored criticism that there are several senses in which meanings can appropriately be said to reside in the intending thinker’s head, especially under available interpretations of the metaphysics of and identity conditions for intending mental acts and their intended objects. The thought experiment loses force if it is said that the identity requirements for a ‘simultaneously’ intending mental act involving ‘Water’ imply achieved reference to H20 on Earth and to XYZ on Twin-Earth. Then the intending mental acts on Earth and Twin-Earth involving the thought ‘Water’ will not in fact, despite superficial appearances, belong even to the same relevant general types or kinds of psychological events.