Scientifically Responsible Metaphysics: A Program for the Naturalization of Metaphysics

There has been much recent work calling for the naturalization of metaphysics, including most famously James Ladyman and Don Ross’ polemic, Every Thing Must Go. But much work remains to adequately articulate and motivate the call to naturalize metaphysics. My dissertation contributes to that work. Its central questions are: What relationship should metaphysics have to current science? Must good metaphysics be responsive to current science, and if so, how? Why should metaphysics be naturalized and what should its naturalization consist in? I argue, first, that for that for epistemic purposes, as opposed to heuristic or pragmatic purposes, theories should be robustly constrained and adequately warranted. The negative portion of the dissertation attacks what I call free range metaphysics — metaphysics, the content of which is constrained not by science, but only by logical, aesthetic, and psychological demands, such as the demands for consistency, simplicity, intuitive plausibility, and explanatory power. I argue that, individually and jointly, the constraints on the content of free range metaphysics are insufficiently robust and their satisfaction fails to secure sufficient epistemic warrant. Therefore, free range metaphysics cannot claim to produce justified theories of reality. The positive portion of the dissertation prescribes scientifically responsible metaphysics — metaphysics conscientiously engaged with the theories and practices of the current sciences. I argue that scientifically responsible metaphysics is better constrained and supported than free range metaphysics and therefore can better claim to justify metaphysical theories. Finally, I consider potential problem cases — cases in which some metaphysical topic is not obviously apt for being made scientifically responsible — including modal metaphysics and grounding. I resolve the problem cases by showing how the topics can be made scientifically responsible. First, I articulate a methodology for scientifically responsible modal metaphysics that takes current science as an evidence-base for the justification of modal claims and as a model of good modal reasoning. Second, I synthesize a list of fruitful uses of science for grounding theorists, including among other things: to help in the identification of putative grounding relata, to show correlations among them, to demonstrate their non-identity, to provide a stock of explanatory patterns, to identify candidate essential properties, and to motivate agnosticism about particular grounding theses where scientific support is lacking. Having resolved the problem cases, I conclude that the prospects for making metaphysics scientifically responsible are bright