In his lectures on Logic and Metaphysics, Kant distinguishes between logical and real essences. While the former is related to concepts and is knowable, the latter is related to things and is unknowable. In this paper, I argue that the unknowability is explained by the modal characteristic of real essences as a necessitating ground on which a priori knowledge is impossible. I also show how this claim is related to the unknowable necessity of particular laws of nature. Since laws of (...) nature are conceived as grounded in real essences, the unknowability of the latter is equivalent to Kant's other claim that there can be no knowledge of the necessity of particular laws of nature. Necessity can only be known a priori, and therefore, the necessity of particular laws is only assumed and conceived as grounded in something unknowable, a real essence. This conclusion will allow me to attribute to Kant a position I label as “regulative essentialism”, meaning that real essences have an indispensable role in accordance with the rational interest to explain nature as a system of laws and natural kinds, combined with an epistemic humility about the correspondence of our empirical concepts to real essences. (shrink)

Kant's theory of the regulative use of ideas of reason has been clarified considerably in recent scholarship. Little attention has been paid, however, to the question of whether the three classes of transcendental ideas—psychological, cosmological, and theological—may differ with regard to their regulative use. This article argues that there is a fundamental difference between the classes of ideas in this respect and that an examination of this heterogeneity can provide much‐needed insight into Kant's account of the utility of the cosmological (...) ideas. First, I set out Kant's distinction between the cosmological ideas and their psychological and theological counterparts. Second, I clarify the two distinct regulative uses of each cosmological idea. I argue that the two opposed sides of the cosmological antinomies provide two different heuristic functions, aligned with the theoretical and practical interests of reason. (shrink)

In this paper I extend the case for a necessitation account of particular laws in Kant's philosophy of science by examining the relation between reason's hypothetical use in the Appendix to the Transcendental Dialectic and the legitimate hypotheses identified in the Doctrine of Method. Building on normative accounts of reason's ideas, I argue that reason's hypothetical use does not describe the connections between objects and their grounds, which lie beyond the reach of the understanding, but merely prescribes the relations between (...) appearances and their conditions, for which the understanding must seek. A legitimate hypothesis, I suggest, is a proposition we hold to be true that fills in one or several of those relations. The problematic character of hypotheses requires that we evaluate our reasons for holding them to be true. While natural modality is grounded in the nature of things, which cannot be fully known, our reasons for assent can and must be grounded on features of objects that are epistemically available to us. (shrink)