Classical theism and modal realism are incompatible
Abstract The classical conception of God is that of a necessary being. On a possible worlds semantics, this entails that God exists at every possible world. According to the modal realist account of David Lewis, possible worlds are understood to be real, concrete worlds no different in kind from the actual world. But, modal realism is equipped to accommodate the existence of a necessary being in only one of three ways: (1) By way of counterpart theory, or (2) by way of a special case of trans world identity for causally inert necessary beings (e.g. pure sets) or else (3) causally potent ones which lack accidental intrinsic properties. I argue that each of these three options entails unacceptable consequences (1) and (2) are incompatible with theism, and (3) is incompatible with modal realism. I conclude that (at least) one of these views is false.
Religious Studies