In this introductory article we reconstruct several broad developments in the scholarship on Kant’s theory of natural science with a particular focus on the Anglophone context over the past half-century. Our goal is to illuminate the co-development of Kant scholarship and the philosophy of science during this period and to identify points of influence in both directions. In section 2 we present an overview of the scholarship on Kant’s account of natural laws. In section 3 we survey the diverse interpretations of Kant’s views on biology and consider recent appeals to Kant by philosophers of biology. In section 4 we explore several recent developments in philosophy of science that have potential synergies with Kant scholarship. Our aim is not simply to establish that Kant’s philosophy can have relevance for philosophy of science but also to point out where it has been and continues to be relevant. Appreciating this relevance, we suggest, can help identify productive lines of inquiry for Kant studies.

An influential strand in philosophy of science claims that scientific paradigms can be understood as relativized a priori frameworks. Here, Kant’s constitutive a priori principles are no longer held to establish conditions of possibility for knowledge which are unchanging and universally true, but are restricted only to a given scientific domain. Yet it is unclear how exactly a relativized a priori can be construed as both stable and dynamical, establishing foundations for current scientific claims while simultaneously making intelligible the transition to a subsequent framework. In this article, I show that important resources for this problem have been overlooked in Kant’s theory of reflective judgement in the third Critique. I argue that Kant accorded the task of formulating new scientific laws to reflective judgement, which is charged with forming new ‘universals’ that guide the experience of nature. I show that this is the very task attributed to the relativized a priori: the constitution of a given conceptual framework, not of the conditions for object-reference as such. I conclude that Kant’s considered conception of science encompasses the operations of both reflective and determining judgement. Relativizations of the a priori should follow Kant’s lead.

Kant’s philosophy of natural science has traditionally concentrated on a host of issues including the role of laws of nature and teleological judgements. However, so far, the literature has made virtually no contact with the no less important tradition in Kant’s legal and political philosophy. This article explores one aspect of such connection in relation to the normative foundations of Kant’s notion of cosmopolitan right. I argue that Kant’s argument for cosmopolitan right is based on two main premises: the first is what I call the law of equilibrium, and the second is the premise of physical interaction (commercium in Latin) at work behind what Kant called the original ‘community of land’. The article argues that the relevant notion of community qua commercium should be understood in the context of Kant’s metaphysics of nature as a ‘real community of substances’ governed by a dynamical law of equality of action and reaction. This metaphysical-causal interpretive reading has far-reaching implications for the foundations of cosmopolitan right and its scope of applicability well beyond Kant’s envisaged right to universal hospitality.

Kant famously distinguishes between the methods of mathematics and of metaphysics, holding that metaphysicians err when they avail themselves of the mathematical method. Nonetheless, in the Metaphysical Foundations of Natural Science, he insists that mathematics and metaphysics must jointly ground ‘proper natural science’. This article examines the distinctive contributions and unity of mathematics and metaphysics to the foundations of the science of body. I argue that the two are distinct insofar as they involve distinctive sorts of grounding relations – mathematics pertains to formal grounding, while metaphysics concerns material grounding – while they are unified insofar as they treat motion, the fundamental determination of the science of body.

This article analyses a sceptical challenge resulting from metaphysical approaches to the problem of the necessity of empirical laws of nature in Kant’s critical philosophy (what I shall call ‘essentialist’ readings). I argue that this challenge may jeopardize the purpose of empirical enquiry (and therefore the plausibility of essentialist readings), but that Kant has internal resources to address it in the Dialectic of the Critique of Pure Reason. I show that reading this problem through the lens of the Dialectic allows us to reconcile the metaphysical question of necessitation of laws with a robust sense of empirical cognition.

Given the central place organisms occupy in Kant’s account of living nature, it might seem unlikely that his claims about biological wholes could be relevant to current debates over the problem of biological individuality. These debates acknowledge the multiple realizability of biological individuality in vastly different forms, including parts of organisms and complex groups of organisms at various levels of the biological hierarchy, sparking much controversy in attempts to characterize a biological individual. I argue that, far from being irrelevant to this controversy, Kant’s account provides a key insight for addressing the multiple realizability problem. I show how the reciprocal causality between a self-organizing whole and its parts, which Kant thinks characterizes a natural end, is not limited to organisms but is exhibited by numerous types of beings in living nature. Self-organizing wholes of various kinds, and at various biological levels, may count as biological individuals, depending on the degree to which their functionally integrated parts are represented by reflective judgement as a natural end.

In The Architectonic of Reason Lea Ypi argues that Kant ultimately fails in his attempt at grounding the systematic unity of reason because of the lack of the practical domain of freedom in the first Critique. I aim to advance a more nuanced reading of Kant’s alleged failure by (1) distinguishing between the schematism of the ideas in the Appendix to the Transcendental Dialectic and the schematism of pure reason in the Architectonic. (2) I suggest that, while the practical domain of freedom is not established in the first Critique, the Canon and the Architectonic do account for its condition: the practical employment of reason and its unity with the theoretical. I point out that while (3) the schematism of the ideas accounts for the sole systematic arrangement of the understanding’s cognitions and the regulative role of the ideas and the ideal, in the Architectonic, (4) the schematism of pure reason instead bears more generally on systematicity as reason’s way of proceeding in framing its own unitary whole and the unity between its two lawful employments.

According to Lea Ypi, Kant’s attempt in the first Critique to unify reason via the practical route fails because his notion of purposiveness as design commits him to a dogmatic metaphysics. I challenge this claim on two grounds. First, I argue that practical reason does not have an interest in a strong modal connection that guarantees the unity of freedom and nature rather than a weak modal connection that merely affirms the possibility of our ends. Second, I highlight that the epistemic status of practical ideas is one of faith or hope rather than knowledge. Hence, Kant’s attempt to unify reason via the practical route can be reconstructed in a way that is largely in line with the commitments of his critical philosophy.

In The Architectonic of Reason, Lea Ypi provides an illuminating and innovative interpretation of the Architectonic in the first Critique. Ypi argues that Kant’s project of uniting practical and theoretical uses of reason in a critical metaphysics ultimately fails because practical reason does not have its own domain in which to legislate. This article challenges Ypi’s objection to practical reason’s lack of a domain in the first Critique. Its main contention is that reason’s need for unity in legislation may be satisfied by a belief in God as a necessary practical presupposition rather than a dogmatic metaphysical reality.