Meta Ontology

In his two recent books on ontology, Universals: an Opinionated Introduction, and A World of States of Affairs, David Armstrong gives a new argument against nominalism. That argument seems, on the face of it, to be similar to another argument that he used much earlier against Rylean behaviourism: the Truthmaker Argument, stemming from a certain plausible premise, the Truthmaker Principle. Other authors have traced the history of the truthmaker principle, its appearance in the work of Aristotle [10], Bradley [16], and even Husserl [15]. But that is not my task --- in this paper I argue that Armstrong's new argument is not logically analogous to the old, and, in particular, that it is quite possible to be a thoroughgoing nominalist, and hold a truthmaker principle