Abstract

A model of metaphysics associated with EJ Lowe and Tuomas Tahko sees metaphysics as involving a priori knowledge of possible essences, or at least modal facts, and delimiting the actual ‘ontological categories,’ the ultimate and essential divisions of what exists, based on the results of a posteriori scientific investigation. Their approach to metaphysics has been criticized by those who argue that such metaphysics is unsuitably a priori, disconnected with empirical research in natural science, and ends up failing to provide meaningful constraints on metaphysical theorization. I present different epistemological and semantic worries about these accounts to motivate an alternative perspective on which metaphysics centers on form, rather than possibility. This scholastic perspective is shown to incorporate the skeptical insights as constitutive of its approach to existence, by way of the position that ‘being’ is not a genus. Rather, ‘being’ is a determinable. The scholastic approach can thus provide responses to the skeptics, since it denies that ontological categories – in the Lowe/Tahko sense – are what metaphysicians investigate and proposes a different view of ontological categories as classes of forms.