Kripkean Counterpart Theory
University of Sussex
Lewis’s counterpart-theoretic semantics for quantified modal logic is
motivated originally by worries about identifying objects across
possible worlds; the counterpart relation is grounded more cautiously on
comparative similarity. The possibility of contingent identity
is an unsought—and in some eyes, unwelcome—consequence of this approach.
In this paper I motivate a Kripkean counterpart theory by way of
defending the prior, pre-theoretical, coherence of
contingent distinctness. Contingent identity follows for free. The
theory is Kripkean in that the counterpart relation is in a sense
stipulated rather than grounded on similarity, and is such
that no object has more than one counterpart at a world. This avoids a
number of objections Fara and Williamson have recently levelled against
counterpart theory generally; their other objections are addressed by
enriching the theory with special quantifiers and actuality operators.