The distinct existences argument revisited

The aim of this paper is to take a fresh look at a discussion about the distinct existences argument that took place between David Armstrong and Frank Jackson more than 50 years ago. I will try to show that Armstrong’s argument can be successfully defended against Jackson’s objections (albeit at the price of certain concessions concerning Armstrong’s view on the meaning of psychological terms as well as his conception of universals). Focusing on two counterexamples that Jackson put forward against Hume’s principle (which is central to Armstrong’s argument), I will argue that they are either compatible with Hume’s principle, or imply a false claim. I will also look at several other considerations that go against Hume’s principle, such as, for example, Kripke’s origin essentialism and counterexamples from aposteriori necessity.