David Lewis is typically interpreted as a class nominalist. One consequence of class nominalism, which he embraced, is that the reduction of ordered pairs, triples, etc to unordered sets of sets is conventional. The reaction by his Australian counterparts D.M. Armstrong and Peter Forrest was that Lewis was not being ontologically serious. This chapter evaluates this debate over serious ontology. It is argued that in one sense Lewis is ontologically serious, but that his additional commitment to structuralism about classes should (...) push him to adopt a trope-theoretic account of naturalness, which opens up another way to respond to the charge of not doing serious ontology. This conclusion is supported by certain remarks he makes in his correspondence, thus revealing how his thinking about properties appears to have evolved from property-egalitarianism to a sparse theory of tropes. (shrink)

David Lewis is widely known for maintaining the bizarre thesis known as genuine modal realism (hereafter, modal realism). He argued for modal realism on grounds of serviceability in On the Plurality of Worlds. However, earlier in Counterfactuals, he proposed a different kind of argument: from talk of ways things might be to possible worlds. In this paper, I examine the evolution of the latter argument in Lewis’s thought and evaluate its place in his overall case for modal realism, especially in (...) light of the alternative theory of modality known as magical ersatzism. I argue that Lewis turns the argument on its head in his critique of magical ersatzism, but that his later commitment to Ramseyan humility subjects him to a similar criticism. Therefore, the argument is, ultimately, a poisoned pawn for Lewis. (shrink)

This chapter by Fisher continues the theme of the relation between Armstrong and Lewis, only Fisher casts the net far wider. He begins by arguing that there were at least two different lines of influence from early twentieth-century behaviourism to the identity theory: one through logical positivism and the other through ordinary language philosophy, the latter involving Place and Smart, and Lewis and Armstrong. It was Armstrong and Lewis who were to have a profound influence on subsequent developments in analytic (...) philosophy, both methodologically and in metaphysics, and it is for this reason that Fisher devotes the rest of his chapter to tracing the origins of their theories of mind and the manner in which the emphases and methodologies deployed in developing their respective theories became the hallmarks of their wider impact on analytic philosophy. (shrink)