Title: 'The Metaphysics of De Re Modality and Modal Paradoxes'
Abstract: Transworld identity and counterpart theory are competing analysis of de re modality. Whilst modal paradoxes, focusing on the transitivity of identity, threaten transworld identity, counterpart theory avoids them altogether. Counterpart theorists hold that this is evidence for adopting counterpart theory, but transworld identity theorists argue that they too can easily solve the paradoxes. Particularly, Salmon (1979, 2005) arguably solves the paradoxes focusing on the transitivity of identity by rejecting the modal logic S4. I will argue that the stand-off between counterpart theory and transworld identity can be broken in favour of counterpart theory. To do this, I put forward a new modal paradox - the ``Two-Worlds Paradox" - which focuses on the symmetry of identity. To consistently solve my paradox, Salmon would have to reject the modal logic B. I argue that Salmon cannot provide independent motivation for rejecting both S4 and B, and thus cannot solve all the paradoxes that threaten transworld identity. The counterpart theorist, on the other hand, can easily avoid my paradox too. I conclude that this is evidence for abandoning transworld identity and accepting counterpart theory.
