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.

In this article we examine Kant’s understanding of toleration by including a study of all instances in which he directly uses the language of toleration and related concepts. We use this study to resolve several key areas of interpretative dispute concerning Kant’s views on toleration. We argue that Kant offers a nuanced and largely unappreciated approach to thinking about toleration, and related concepts, across three normative spheres: the political, the interpersonal and the personal. We examine shortcomings in earlier interpretations and conclude by arguing that the theme of toleration in Kant’s work, while coherent and important, is neither as central nor as peripheral as suggested by previous interpretations. Further, while Kant is critical of the arrogance of toleration in the political sphere, he is more positive toward the role of toleration in the interpersonal and personal spheres since it promotes virtue.

In a lecture that Habermas gave on his 90th birthday he ironically, but with serious intent, called a good Kant a sufficiently Marxist educated Kant. This dialectical Kant is the only one of the many Kants who maintains the idea of an unconditioned moral autonomy but completely within evolution, history and in the middle of societal class and other struggles. The article tries to show what Kant could have learned from his later critics to enable him to become a member of the Frankfurt School’s neo-Marxist theory of society.

This article discusses five attempts at justifying the provision of welfare on Kantian grounds. I argue that none of the five proposals is satisfactory. Each faces a serious challenge on textual or systematic grounds. The conclusion to draw from this is not that a Kantian cannot defend the provision of welfare. Rather, the conclusion to draw is that the task of defending the provision of welfare on Kantian grounds is a difficult one whose success we should not take for granted.

Many of us are all too familiar with the experience of taking pleasure in things we feel we ought not, and of finding it frustratingly hard to bring our pleasures into line with our moral judgements. As a value dualist, Kant draws a sharp contrast between the two sources of practical motivation: pleasure in the agreeable and respect for the moral law. His ethics might thus seem to be an unpromising source for help in thinking about how we can bring our agreeable pleasures into line with our moral values. But I argue that a careful reading of Kant’s texts reveals a helpfully realistic view about the extent to which we can modify our agreeable pleasures. On my interpretation, Kant shows us how to hold together two seemingly incompatible ideas: on the one hand, that pleasure in the agreeable is resistant to rational direction, and on the other hand, that we can cultivate these pleasures with a view to ethical self-transformation.

Kant’s discussion of the highest good is subject to continuous disagreement between the proponents of two interpretations of this concept. According to the secular interpretation, Kant conceived of the highest good as a political ideal which can be realized through human agency alone, albeit only from the Critique of the Power of Judgement onwards. By way of contrast, proponents of the theological interpretation find Kant’s treatment of the highest good in his later works to be wholly coherent with the discussions of this concept found in the second Critique. In their view, however, Kant never conceived of the highest good as a political ideal, and some go as far as to argue that it is the work of God alone. In this article, I defend a theologico-political account of the highest good that avoids the pitfalls of both readings.

Kant’s anthropological lectures introduce scepticism about our psychological capacity to experience happiness conceived as gratification or contentment. Aesthetic experience is in a position to inform an alternative conception of happiness that not only is more adequate to the idea of happiness than either gratification or contentment but also may more easily conform to the moral law’s constraints than gratification. As an ‘ideal feeling’, pleasure in beauty serves as a model for how best to enjoy even sensual pleasures and otherwise ‘private’ sensations. In the end, the third Critique suggests that this alternative conception is more ‘appropriate’ to humankind (§60, 5: 355).

Theodor W. Adorno often made reference to Immanuel Kant’s famous essay on enlightenment. Although he denied that immaturity is self-incurred, the first section of this article will show that he adopted many of Kant’s ideas about maturity in his philosophically informed critique of monopoly conditions under late capitalism. The second section will explore Adorno’s claim that the educational system could foster maturity by encouraging critical reflection on the social conditions that have made us what we are. Finally, this article will demonstrate that Adorno links enlightenment to Kant’s idea of a realm of ends.

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.

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.

Habermas dialogically recasts the Kantian conception of moral autonomy. In a legal-political context, his dialogical approach has the potential to redress certain troubling features of liberal and communitarian approaches to democratic politics. Liberal approaches attach greater normative weight to negatively construed individual freedoms, which they seek to protect against the interventions of political authority. Communitarian approaches prioritize the positively construed freedoms of communal political participation, viewing legal-political institutions as a means for collective ethical self-realization. Habermas’ discourse theory of law and democracy seeks to overcome this competition between the negative and positive liberties. Doing so entails reconciling private and public autonomy at a fundamental conceptual level. This is his co-originality thesis, which seeks to show that private and public autonomy are internally connected and evenly balanced. I support his aim but argue that he fails to achieve it due to an unsatisfactory account of private autonomy. I suggest an alternative dialogical conception of autonomy as ethically self-determining agency that would enable him to establish his thesis.

The so-called ‘possibility proof’ in Kant's pre-Critical Beweisgrund has been widely discussed in the literature, and it is a common view that he never really abandoned it. As I shall argue, this reading is mistaken. I aim to show that the natural illusion in the Critique of Pure Reason, which is usually taken to be the possibility proof turned into a transcendental illusion, has both a different conclusion and a different argument than the possibility proof. Rather, what remains from Beweisgrund is what I will call the ‘proof a posteriori’, which the Critique turns into a transcendental illusion that is of regulative use for reason.

Scholars working on Kant’s Anticipations of Perception generally attribute to him an argument that invalidly infers that objects have degrees of intensive magnitude from the premise that sensations do. I argue that this rests on an incorrect disambiguation of Kant’s use of Empfindung (sensation) as referring to the mental states that are our sensings, rather than the objects that are thereby sensed. Kant’s real argument runs as follows. The difference between a representation of an empty region of space and/or time and a representation of that same region as occupied by an object entails that, in addition to their extensive magnitude, objects must be represented as having a matter variable in intensive magnitude. Since it is the presence of sensation (sensing) in a cognition that marks the difference between representing only the extensive magnitude of the object and the object as a whole, it is sensation that represents its intensive magnitude.

The article argues that Kant’s argument for ownership entails a standard of meaningful use by which property regimes can be evaluated: a regime must make it possible for usable objects to be meaningfully used. A particular form of fully communal ownership can satisfy this standard. Further, this form of communal ownership is compatible with Kantian freedom more broadly. I conclude that, if this is so, there is a great deal of space for further consideration of the rightfulness of diverse regimes of ownership and exchange within a Kantian framework.

An influential interpretation of Kant’s Doctrine of Right suggests that the relationship between public right and freedom is constitutive rather than instrumental. The focus has been on domestic right and members’ relations to their own state. This has resulted in a statist bias which has not adequately dealt with the fact that Kant regards public right as a system composed of three levels – domestic, international and cosmopolitan right. This article suggests that the constitutive relationship is between all levels of right, on the one hand, and ‘freedom in the external relation’ of all human beings, on the other hand.

In this article I press four different objections on Forst’s theory of the ‘Right to Justification’. These are (i) that the principle of justification is not well-formulated; (ii) that ‘reasonableness and reciprocity’, as these notions are used by Rawls, are not apt to support a Kantian conception of morality; (iii) that the principle of justification, as Forst understands it, gives an inadequate account of what makes actions wrong; and (iv) that, in spite of his protestations to the contrary, Forst’s account veers towards a version of moral realism that is prima facie incompatible with Kantian constructivism. I then evaluate Forst’s theory in the light of a distinction made by Sharon Street between restricted and unrestricted constructivism. I show that Forst has reason to deny that it is either the one or the other, but he is not able to show that it is both or neither. I conclude that the arguments Forst advances in support of his constructivist theory of the right to justification entail that it is a metaphysical and comprehensive conception in the relevant, Rawlsian sense. Forst’s theory of the right to justification therefore fails to fulfil one of the main stated aims.

Must we ascribe hope for better times to those who (take themselves to) act morally? Kant and later theorists in the Frankfurt School tradition thought we must. In this article, I disclose that it is possible – and ethical – to refrain from ascribing hope in all such cases. I draw on two key examples of acting irrespective of hope: one from a recent political context and one from the life of Jean Améry. I also suggest that, once we see that it is possible to make sense of (what I call) ‘merely expressive acts’, we can also see that the early Frankfurt School was not guilty of a performative contradiction in seeking to enlighten Enlightenment about its (self-)destructive tendencies, while rejecting the (providential) idea of progress.

Both critics and defenders of Kant’s Religion within the Boundaries of Mere Reason have raised worries about its alleged employment of an ‘Augustinian’ conception of moral evil as well as the accounts of grace and moral regeneration consequent to it. Combined, these aspects of the Religion are often seen as responsible for its principal ‘wobble’, ‘conundrum’ or ‘internal contradiction’, and are likewise among the key reasons why the Religion is commonly seen as at odds with the epistemic strictures and moral principles which shape Kant’s broader Critical corpus. It is the purpose of this article to reassess these charges and to show thereby that rather than accepting this alleged Augustinianism, Kant engages with and ultimately rejects its core tenets.

Recently, a number of Kantians have argued that despite Kant’s own disparaging comments about same-sex intercourse and marriage, his ethical and legal philosophy lacks the resources to show that they are impermissible. I go further by arguing that his framework is in fact more open to same-sex than to different-sex marriage. Central is Kant’s claim that marriage requires equality between spouses. Kant himself thought that men and women are not equal, and some of his more insightful remarks on the issue reveal that he was also aware that, as a matter of fact, women were disenfranchised by society, and suffer legal and other forms of discrimination. Kant, according to his own account, cannot approve of heterosexual marriage. Same-sex couples, by contrast, can satisfy the crucial equality condition. I conclude with a suggestion for refocus with respect to the issues at hand, calling for attention to more complex and insidious forms of inequality than deprivation of rights and full civil participation.

Marcus Willaschek’s new book Kant on the Sources of Metaphysics: The Dialectic of Pure Reason (Cambridge University Press, 2018) is a penetrating analysis of the Transcendental Dialectic of Kant’s Critique of Pure Reason. In his comments, the author first raises some questions concerning the structure of the Transcendental Dialectic (and Willaschek’s reconstruction of it) and then proposes that looking at the second Critique and continuing on into the third Critique will reveal more roles for the idea of God in Kant’s reconstruction of traditional metaphysics than Willaschek’s treatment suggests.