Counterparts and Actuality
1 Sage School of Philosophy, 218 Goldwin Smith Hall, Cornell University, Ithaca, NY 14853, USA michael.fara{at}cornell.edu, 2 New College, Oxford OX1 3BN, UK timothy.williamson{at}philosophy.oxford.ac.uk
Many philosophers, following David Lewis, believe that we should look to counterpart theory, not quantified modal logic, as a means of understanding modal discourse. We argue that this is a mistake. Significant parts of modal discourse involve either implicit or explicit reference to what is actually the case, raising the question of how talk about actuality is to be represented counterpart-theoretically. By considering possible modifications of Lewis's counterpart theory, including actual modifications due to Graeme Forbes and Murali Ramachandran, we argue that no coherent version of counterpart theory can provide a plausible representation of talk about actuality, and so, we conclude, counterpart theory should be rejected.