Volume 112, Issue 8, August 2015
Actualist Counterpart Theory
Actualist counterpart theory replaces David Lewis’s concrete possible worlds and individuals with ersatz worlds and individuals, but retains counterpart theory about de re modality. While intuitively attractive, this view has been rejected for two main reasons: (i) the problem of indiscernibles and (ii) the Humphrey objection. I argue that in insisting that ersatz individuals play the same role as Lewisian individuals, actualists commit the particularist fallacy. The actualist should not (as commonly believed) require stand-ins for every Lewisian individual. Ersatz individuals should instead be construed as representations of actually existing qualitative ways for individuals to be, or qualitative properties individuals can instantiate. This necessitates changes elsewhere. Non-instrumental uses of Kripke semantics and standard counterpart semantics also require stand-ins for particular non-actual individuals. I argue that the actualist should instead adopt a non-standard counterpart semantics that more clearly illuminates the role that actual properties and relations play in explaining de re possibilities and necessities. The result is an intuitive and forceful reply to both the problem of indiscernibles and the Humphrey objection.