Scientific Ontology: Integrating Naturalized Metaphysics and Voluntarist Epistemology contends that ontological commitments associated with scientific inquiry are infused with philosophical commitments. Interpretations of scientific ontology involve (what I call) metaphysical inferences, and furthermore, there are different ways of making these inferences, on the basis of different but nonetheless rational epistemic stances. If correct, this problematizes any neat distinction between naturalized and other metaphysics, and dissolves any presumption of there being a uniquely correct answer to ontological questions connected to the sciences. In this paper, I consider some weighty challenges to these contentions by Amanda Bryant, Stathis Psillos, and Matthew Slater.

Crispin Wright maintains that the architecture of perceptual justification is such that we can acquire justification for our perceptual beliefs only if we have antecedent justification for ruling out any sceptical alternative. Wright contends that this principle doesn't elicit scepticism, for we are non-evidentially entitled to accept the negation of any sceptical alternative. Sebastiano Moruzzi has challenged Wright's contention by arguing that since our non-evidential entitlements don't remove the epistemic risk of our perceptual beliefs, they don't actually enable us to acquire justification for these beliefs. In this paper I show that Wright's responses to Moruzzi are ineffective and that Moruzzi's argument is validated by probabilistic reasoning. I also suggest that Wright couldn't answer Moruzzi's challenge without weakening the support available for his conception of the architecture of perceptual justification.