Natures, ideas, and essentialism in Kant

Despite recent essentialist approaches to Kant’s laws of nature, it is unclear whether Kant’s critical philosophy is compatible with core tenets of essentialism. In this paper, I first reconstruct Kant’s position by identifying the key metaphysical and epistemological features of his notion of ‘nature’ or ‘essence’. Two theses about natures can be found in the literature, namely that they are noumenal in character (_noumenal thesis_) and that they guide scientific investigation as regulative ideas of reason (_regulative thesis_). I argue that Kant’s notion of nature does not entail the noumenal thesis and, based on his model of causal explanation, I propose a novel, _phenomenal thesis_, that allows for a better understanding of the function of natures as regulative ideas. In the last part of the paper, I show that Kant’s ‘essentialism’ is a genuine form of essentialism committed to _de re_ modality, although it differs in several respects from major contemporary essentialist accounts. I conclude by suggesting that Kant’s essentialism (if appropriately updated) can be relevant to the contemporary debate, which has so far been dominated by Humean and Aristotelian proposals.