Andrew Chignell recently proposed an original reconstruction of Kant's ‘Only Possible Argument’ for the existence of God. Chignell claims that what motivates the ‘Grounding Premise’ of Kant's proof, ‘real possibility must be grounded in actuality’, is the requirement that the predicates of a really possible thing must be ‘really harmonious’, i.e. compatible in an extra-logical or metaphysical sense. I take issue with Chignell's reconstruction. First, the pre-Critical Kant does not present ‘real harmony’ as a general condition of real possibility. Second, the real harmony requirement is not what motivates the ‘Grounding Premise’ of the proof. Instead, this premise is sufficiently motivated by what Chignell labels the ‘content’ requirement. Finally, Kant's downgrading of the proof in his Critical period is not based on a concern regarding the real harmony of the predicates of God, but on his Critical restrictions on cognition in general and modal cognition in particular.

There has been a groundswell of interest in the account of modality that Kant sets forth in his pre-Critical Only Possible Argument. Andrew Chignell's reconstruction of Kant's theistic argument in terms of what he calls ‘real harmony’ has a prima facie advantage in that it appears to be able to block the plurality objection (namely, that even if every modal fact presupposes some ground, this does not entail that all modal facts share the same ground). I argue that it is both textually and philosophically problematic to interpret Kant's argument in terms of real harmony. Then, I set forth an alternative response to the plurality objection which does not require the adoption of the problematic notion of real harmony. Instead, I argue that the objection can be overcome by observing that the argument seeks to ground modal facts as a totality and that, according to Kant, such relations can be accounted for only by their schematization in a single intellect.

I reply to recent criticisms by Uygar Abaci and Peter Yong, among others, of my reading of Kant's pre-Critical ‘possibility proof’ of God's existence, and of its fate in the Critical period. Along the way I discuss some implications of this debate for our understanding of Kant's modal metaphysics and modal epistemology generally.

Surprisingly often Kant asserts that it is possible to behave in such a degrading way that one ‘throws oneself away’ and turns oneself ‘into a thing’, as a result of which others may treat one ‘as they please’. Rather than dismiss these claims out of hand, I argue that they force us to reconsider what is meant and required by ‘respect for humanity’. I argue that to ‘throw away’ humanity is not to lose or extinguish it, but rather to refuse or otherwise fail to claim the respect that it authorizes one to claim. If I refuse or fail to make this claim, there is a sense in which I become a thing, and I leave others no choice but to treat me as such. This is compatible with their respect for humanity in my person.

According to the standard reading of Kant's formula of universal law (FUL), positive duties can be derived from FUL. In this article, I argue that the standard reading does not work. In the first section, I articulate FUL and what I mean by a positive duty. In the second section, I set out an intuitive version of the standard reading of FUL and argue that it does not work. In the third section, I set out a more rigorous version of the standard reading of FUL and argue that even this more rigorous version does not work.

A core thesis of Kitcher's is that thinking about objects requires awareness of necessary connections between one's object-directed representations ‘as such’ and that this is what Kant means by the transcendental unity of apperception. I argue that Kant's main point is the spontaneity or ‘self-made-ness’ of combination rather than the requirement of reflexive awareness of combination, that Kitcher provides no plausible account of how recognition of representations ‘as such’ should be constituted and that in fact Kant himself appears to lack the theoretical resources to clearly distinguish between (first-level) consciousness and self-consciousness or apperception properly so-called.

In her new book, Patricia Kitcher supports Onora O'Neill's view that the categorical imperative is the highest principle of both practical and theoretical reason. I claim that neither O'Neill's original interpretation nor Kitcher's additional evidence in favour of it are convincing. At its core, this misconception of Kant's position consists in the identification of self-referential critique of reason with the concept of autonomy. It will be shown that the ‘common principle’ (Kant) of both practical and theoretical reason is not the categorical imperative, but the reflective power of judgement, as Kant claims in the Critique of the Power of Judgement.

I argue that Patricia Kitcher's Kant-inspired account of self-consciousness overintellectualizes the requirements for rational cognition. Kitcher claims that a person can only believe something on the ground of another belief if she is able to recognize the grounding belief as grounding the first belief and as one of her own. I criticize this claim by arguing that (i) someone can believe something for a certain reason without recognizing this reason as a reason (the possibility of unreflected reasons), and that (ii) she can recognize something as a reason for something else without being able to self-ascribe either her original belief or the belief that grounds it (the possibility of reflected but not self-conscious reasons).

In chapter 15 of Kant's Thinker, Patricia Kitcher claims that we can treat Kant as ‘our contemporary’, and that his theory of apperception ‘offers “new” and plausible perspectives on issues of considerable recent interest’. I question this with respect to two of her four chosen topics. First, I address her attempt to show that Kant's theory of apperceptive self-knowledge is immune to sceptical doubts of the sort Barry Stroud presents. Second, I turn to her argument that this theory is superior to current accounts of the special authority of self-knowledge. Over and above specific weaknesses, it seems that Kitcher's considerations generally lack sufficient reflection on how philosophical arguments of the past can be relevant to current agendas.

The article deals with Kant's theory of the self in Patricia Kitcher's Kant's Thinker in three respects: (1) I argue that it is doubtful whether accompanying representations with the ‘I think’ as such yields a principle for the categories since it does not require any strong kind of connection between them. (2) I discuss textual evidence for and against Kitcher's attempt to make sense of Kant's claim that the ‘I think’ requires the continued existence of cognizers per se. (3) I ask whether Kitcher's understanding of Kant's positive theory of the self leans towards minimal substantialism or towards functionalism.