Metaphysical accounts of modality: A comparative evaluation of Lewisian and neo-Aristotelian modal metaphysics

Abstract

In this essay I comparatively evaluate two realist metaphysical accounts of modality: David Lewis’ (1986) genuine modal realism (GMR), and neo-Aristotelian modal realism (AMR) as put forth by Alexander Pruss (2011). GMR offers a reductive analysis of modal claims of possibility and necessity in terms of claims quantifying over concrete worlds and counterparts, and is in this way committed the existence of a plurality of concrete worlds other than the actual world; AMR, on the other hand, offers an analysis of modal claims in terms of claims about the causal powers of existing objects in the actual world, and identifies these powers and powerful properties as the truthmakers for modal truths of possibility and necessity. I consider two objections to GMR; firstly, that it leads to ethical paradoxes, and secondly, that the counterparts it offers as truthmakers for modal claims are fundamentally irrelevant to the de re modal properties of objects. I argue that AMR bears a prima facie advantage over GMR by reason of its avoidance of those two objections, before evaluating two objections faced by AMR itself, namely, that its analysis is not genuinely explanatory, and secondly, that the ontology of powers fails to account for the full range of metaphysical possibility. I argue that AMR has the resources to avoid these objections, that AMR on balance is more attractive, and that therefore AMR is worthy of serious consideration by advocates of GMR. References LEWIS, DAVID K. (1986). On the plurality of worlds. New York, NY, USA: B. Blackwell. PRUSS, ALEXANDER R. (2011). Actuality, Possibility, and Worlds. London: Continuum.