Plantinga's defence of serious actualism

Abstract

IN a series of papers ([2], [3], [4]) Alvin Plantinga has argued for serious actualism, the thesis that necessarily everything is such that necessarily if it has a property, then it exists. In this paper I argue that Plantinga's latest argument for serious actualism is flawed in two respects. Serious actualism entails that no actual object has a property in a possible world in which it does not exist. (I follow Plantinga in using modal operators and quantification over possible worlds interchangeably.) So serious actualism is false if Socrates has a property in a world in which he does not exist. There are certainly worlds in which Socrates does not exist, and it at least seems that in those worlds Socrates does have some properties, for example, the property of non-existence. Plantinga defends serious actualism against the apparent counterexample posed by non-existence in reply to papers by Pollock and Fine ([4], pp. 318-19, 345-6). Building on this defence, Plantinga goes on to give a positive argument for serious actualism. I believe that both the defence and the positive argument are flawed.