Metaphysics without Naturalness

This dissertation challenges the notion of metaphysical naturalness, roughly the idea that certain concepts, predicates, and logical vocabulary (such as quantifiers) carve reality closer to the joints than others. The notion of metaphysical naturalness is ubiquitous, playing a central role in accounts of laws of nature, intrinsicality, similarity, linguistic and mental content, and the substantivity of ontological disputes. In the first part of the dissertation I argue that metaphysics is methodologically well-founded, and that there is no need to appeal to irreducible metaphysical naturalness of quantifiers in order to resist arguments to the effect that ontological disputes (such as whether there are composite material objects, i.e., things with parts) aren’t substantive. My strategy involves offering a new proposal for securing the substantivity of ontological disputes that appeals only to theoretical virtues such as parsimony and explanatory power. The metaontological position I develop has a number of advantages over rivals, including providing a means to reconcile our commonsense beliefs about ordinary objects with the sometimes-wild claims made by ontologists (e.g., that there are no composite objects). In the second part of the dissertation I argue that one can secure determinacy of linguistic content without invoking metaphysically natural properties as “reference magnets.” Donald Davidson, David Lewis, and others have defended the view that linguistic content is determined by whatever interpretation assigns the correct semantic values to the sentences of a linguistic community. These simple interpretationist accounts of linguistic content face a problem with determinacy of reference: they imply that too many different interpretations of our language count as correct. The standard strategy to avoid the problem is to maintain that natural properties are more eligible to be the meanings of our terms (i.e. reference magnets). I argue that this solution is inadequate and defend a new version of interpretationism that appeals to facts about rationality and value to secure determinacy of reference. Although the invocation of these normative facts makes my strategy less naturalistic, I show that proponents of the standard strategy must presuppose the relevant normative facts anyway—the standard view is no more naturalistic in the end.