Kant’s regulative metaphysics of particular laws of nature: reconciling best-system and necessitation accounts

Abstract Kant maintains that particular laws of nature are discovered empirically yet are taken to be necessary. This raises the question of how to account for their necessity. Two leading interpretations emerged: the best system account (BSA) and the necessitation account (NA). BSA provides a methodological-epistemological account for the regularities that can be justifiably considered as laws of nature. On the other hand, NA provides an account of what it is to be a law of nature in terms of metaphysical explanatory grounds. While the interpretations are different in nature, there is textual evidence in Kant for both. In this paper, I aim to explain the duality of the interpretations and reconcile them. I present how they are intertwined in Kant’s works, first by pointing out the metaphysical content of the idea of God which grounds the unity and necessity of the laws of nature. Secondly, I argue that both accounts share an epistemic status as regulative ideas which I interpret as expressing rational norms of scientific inquiry. Thus, Kant maintains that scientific inquiry encompasses a single norm of explanation in which the systematicity and necessity of the laws of nature are interdependent. This norm is expressed in metaphysical concepts such as essences, powers, and most importantly the regulative idea of God. Finally, I consider the relevance of this unified account to contemporary debates about the laws of nature by suggesting that the Kantian regulative framework could explain and deflate questionable ontological commitments by identifying metaphysical terms as expressions of norms.