Nick Stang,University of Toronto :: Abducting Metaphysics
Friday, October 28, 2022

Abstract: A notable feature of analytic philosophy in the past few decades has been the resurgence of metaphysics and the return of many classical topics of rationalist metaphysics (e.g. modality, grounding, the principle of sufficient reason). The dominant view within this resurgence is that metaphysics is, methodologically and epistemically, based on abduction (inference to the best explanation). I call this view abductivism about metaphysics. I begin by pointing out that explanations are sensitive to the language in which they are couched. Even if the world is replete with explanatory structure (e.g. the PSR holds), if our language does not 'carve' that structure 'at its joints,' abductive inferences carried out in that language will not be explanatorily succesful (they will not infer the real explanans), even if they are systematically truth-tracking (they infer true conclusion). Abductive metaphysics, I argue, will thus fail if our language does not carve the world at its metaphysical joints. I then turn to the most prominent theory of why our language carves the world at its joints, the theory of structure in Sider 2011. I argue that, appearances to the contrary, Sider merely assumes that our language carves at the structural joints, and does not genuinely explain why this is the case. Abductive metaphysics, I conclude, cannot explain its own possibility.