In his Kant on Laws, Eric Watkins presents an account of reason on which the principles of specification and continuity are regulative instructions to search for different kinds of the unconditioned. I suggest that we correct Watkins’ account in two ways. First, we need to complete Watkins’ claim to the plurality of the unconditioned: reason aims for three kinds of the unconditioned, associated with the lowest, next and highest concepts. Second, we need to look beyond reason’s search for the unconditioned in order to properly understand the nature of the aim of reason. I argue that we construe reason’s aim as the systematic unity of cognition considered as a whole or, in Kant’s teleological terms, as the realization of an ‘idea’, or a ‘purposive unity’.

I draw attention to a 12-page Vorarbeit to Kant’s Prolegomena from the so-called Scheffner-Nachlaß and argue that the parallel Kant draws there between the possibility of theoretical and practical synthetic a priori propositions provides important insight into the development of his account of practical autonomy in the Groundwork. Based on a brief sketch of the role synthetic a priori propositions play in the development of Kant’s critical philosophy, I conclude that for Kant the objective validity of any science depends on the objective validity of a number of synthetic a priori propositions.

I discuss three sets of worries concerning Watkins’ account of laws of nature in Kant on Laws. First, I argue contra Watkins that Kant’s laws of nature do not depend on acts of prescription in any literal sense. Second, I question how his generic conception of laws applies to empirical laws of nature and suggest that the worries about unknowability or contingency that he raises for contemporary alternatives may equally arise for empirical laws on Kant’s account. Finally, I discuss his claim that Kant’s a priori laws depend on the immutability of human cognitive capacities and ask how this immutability should be understood.

This article explains Kant’s claim that sciences must take, at least as their ideal, the form of a ‘system’. I argue that Kant’s notion of systematicity can be understood against the background of de Jong and Betti’s Classical Model of Science (2010) and the writings of Georg Friedrich Meier and Johann Heinrich Lambert. According to my interpretation, Meier, Lambert and Kant accepted an axiomatic idea of science, articulated by the Classical Model, which elucidates their conceptions of systematicity. I show that Kant’s critique of the mathematical method is compatible with his adherence to this axiomatic conception of science. I further show that systematicity advances traditionally accepted logical ideals of scientific knowledge, which explains why Meier and Kant think that sciences must be ‘systematic’.

After summarizing the content of my book, Kant and Mysticism (Palmquist 2019), I warn against four preliminary misconceptions. The book never argues that Kant viewed himself as a mystic, fully acknowledges Kant’s negative view of mysticism, offers no comprehensive overview of mystical traditions, and aims to initiate a dialogue, not to have the final word. I then respond to the foregoing essays by the five critics.

The prohibition on using others ‘merely as means’ is one of the best-known and most influential elements of Immanuel Kant’s moral theory. But it is widely regarded as impossible to specify with precision the conditions under which this prohibition is violated. On the basis of a re-examination of Kant’s texts, the article develops a novel account of the conditions for using someone ‘merely as a means’. It is argued that this account has not only strong textual support but also significant philosophical advantages over alternative conceptions.

The nature of Kant’s criticism of his pre-Critical ‘possibility proof’ for the existence of God, implicit in the account of the Transcendental Ideal in the Critique of Pure Reason, is still under dispute. Two issues are at stake: the error in the proof and diagnosis of the reason for committing it. I offer a new way to connect these issues. In contrast with accounts that locate the motivation for the error in reason’s interest in an unconditioned causal ground of all contingent existence, I argue that it lies in reason’s interest in another kind of unconditioned ground, collective unity. Unlike the conception of the former, that of the latter directly explains the problematic ontological assumption of the possibility proof, the existence of intelligible objects as the ground of possibility. I argue that such Platonic entities are assumed because they are amenable to the kind of unity prescribed by reason. However, since the interest in collective unity has a legitimate regulative use when applied to the systematic unity of nature, the conception of God entailed by the possibility proof is retained as a regulative idea of reason.

Commentators disagree about Kant’s view on the proper treatment of emotions. In contrast to a tendency in this literature to treat them uniformly, I argue that, according to Kant, feelings (but not affects) require cultivation, and inclinations – although they can and perhaps may be cultivated – generally require discipline. The appropriate treatment for emotions depends on their susceptibility to rational constraint and on the threat they pose to rational deliberation. Although I read Kant as recommending that we cultivate certain emotions, I argue that my reading is not vulnerable to Thomason’s recent pertinent objections to such readings.