I offer a new reconstruction of Hegel’s criticism of Kant’s idealism. Kant held that we impose categorial form on experience, while sensation provides its matter. Hegel argues that the matter we receive cannot guide our imposition of form on it. Contra recent interpretations, Hegel’s argument does not depend on a conceptualist account of perception or a view of the categories as empirically conditioned. His objection is that given Kant’s dualistic metaphysics, the categories cannot have material conditions for correct application. This (...) leads to subjectivism in the content of experience: the subject is given an implausibly strong role in determining what is the case. Hegel’s own absolute idealism solves this problem. (shrink)

The book addresses two main areas of Kant’s theoretical philosophy: the doctrine of transcendental idealism and various central aspects of the arguments from the Metaphysical and Transcendental Deductions, as well as the relation between the deduction argument and idealism. -/- Among the topics covered are the nature of objective validity, the role and function of transcendental logic in relation to general or formal logic, the possibility of contradictory thoughts, the meaning of the Leitfaden at A79 and the unity of cognition, (...) the two-steps-in-one-proof interpretation and categorial instantiation, categorial illusion, Strawson’s transcendental argument, the persistently perplexing question of the derivation of the categories, and the relation between apperception, objectivity, judgement, and idealism. -/- With regard to idealism in particular, the focus is on the metaphysical two-aspect interpretation and its problems, on the merits and demerits of the controversial phenomenalist reading of Kant’s idealism, and on the topic of subjectivism and epistemic humility. -/- In all of the aforementioned topics, the book presents wholly novel interpretations compared to the standard or mainstream interpretations. (shrink)

A historical and philosophical reassessment of the impact of Aristotle and early-modern Aristotelianism on the development of Kant’s transcendental philosophy. Kant and Aristotle reassesses the prevailing understanding of Kant as an anti-Aristotelian philosopher. Taking epistemology, logic, and methodology to be the key disciplines through which Kant’s transcendental philosophy stood as an independent form of philosophy, Marco Sgarbi shows that Kant drew important elements of his logic and metaphysical doctrines from Aristotelian ideas that were absent in other philosophical traditions, such as (...) the distinction of matter and form of knowledge, the division of transcendental logic into analytic and dialectic, the theory of categories and schema, and the methodological issues of the architectonic. Drawing from unpublished documents including lectures, catalogues, academic programs, and the Aristotelian-Scholastic handbooks that were officially adopted at Königsberg University where Kant taught, Sgarbi further demonstrates the historical and philosophical importance of Aristotle and Aristotelianism to these disciplines from the late sixteenth century to the first half of the eighteenth century. (shrink)

Overview of the (non)conceptualism debate in Kant studies.

The metaphysical “Law of Continuity of Alterations” says that whenever an object alters from one state to another, it passes through a continuum of intermediate states. Kant treated LCA as a transcendental law of understanding. The primary purpose of the paper is to reconstruct and evaluate Kant’s three arguments for LCA. All three are found to be inadequate. However, a secondary goal of the paper is to show that LCA would have more naturally been construed as a regulative principle of (...) reason. I conclude with some remarks about how this could work. (shrink)

Kant holds that the applicability of the moral ‘ought’ depends on a kind of agent-causal freedom that is incompatible with the deterministic structure of phenomenal nature. I argue that Kant understands this determinism to threaten not just morality but the very possibility of our status as rational beings. Rational beings exemplify “cognitive control” in all of their actions, including not just rational willing and the formation of doxastic attitudes, but also more basic cognitive acts such as judging, conceptualizing, and synthesizing.

Kant’s account of cognitive judgment is sophisticated, sound and philosophically far more illuminating than is often appreciated. Key features of Kant’s account of cognitive judgment are widely dispersed amongst various sections of the Critique of Pure Reason, whilst common philosophical proclivities have confounded these interpretive difficulties. This paper characterises Kant’s account of causal-perceptual judgment concisely to highlight one central philosophical achievement: Kant’s finding that, to understand and investigate empirical knowledge we must distinguish between predication as a grammatical form of sentences, (...) statements or judgments, and predication as a cognitive act of ascribing some characteristic to some localised particular. With Kant’s finding in view, I then elucidate how we have occluded his achievement. My results are not merely interpretive, but philosophical, because they show that Kant’s account of perceptual judgment accords with – and indeed justifies – a central and sound point regarding language, thought and reference advocated by apparently unlikely philosophical comrades. These finding highlight some methodological cautions which require re-emphasis today. (shrink)

According to received wisdom, Kant takes the laws of logic to be normative laws of thought. This has been challenged by Tolley (2006). In this paper, I defend the received wisdom, but with an important modification: Kant's logical laws are constitutive norms for thought. The laws of logic do tell us what thinking is, not because all thoughts are in conformity with logical laws, but because all thoughts are, by nature, subject to the standard of logic.

I present an argument for an interpretation ofKant's views on the nature of the ‘content [Inhalt]’ of ‘cognition [Erkenntnis]’. In contrast to one of the longest standing interpretations ofKant's views on cognitive content, which ascribes toKant a straightforwardly psychologistic understanding of content, and in contrast as well to the more recently influential reading ofKant put forward byMcDowell and others, according to whichKant embraces a version ofRussellianism, I argue thatKant's views on this topic are of a much moreFregean bent than has (...) traditionally been admitted or appreciated. I conclude by providing a sketch of how a better grasp ofKant's views on cognitive content in general can help bring into sharper relief what is, and what is not, at stake in the recent debates over whether Kant accepts a particular kind of cognitive content—namely, non‐conceptual content. (shrink)

In this chapter I highlight the apparent tensions between Kant’s very stringent critique of metaphysical speculation in the “Discipline of Pure Reason” chapter and his endorsement of Belief (Glaube) and hope (Hoffnung) regarding metaphysical theses in the subsequent “Canon of Pure Reason.” In the process I will examine his distinction between the theoretical and the practical bases for holding a “theoretical” conclusion (i.e. a conclusion about “what exists” rather than “what ought to be”) and argue that the position is subtle (...) but coherent. In the second part of the paper I focus on Kant’s account of rational hope in the Doctrine of Method: its nature, scope, conditions, and role in the philosophy of religion generally. (shrink)

One of the central debates in contemporary Kant scholarship concerns whether Kant endorses a “conceptualist” account of the nature of sensory experience. Understanding the debate is crucial for getting a full grasp of Kant's theory of mind, cognition, perception, and epistemology. This paper situates the debate in the context of Kant's broader theory of cognition and surveys some of the major arguments for conceptualist and non-conceptualist interpretations of his critical philosophy.

Call the idea that states of perceptual awareness have intentional content, and in virtue of that aim at or represent ways the world might be, the ‘Content View.’ I argue that though Kant is widely interpreted as endorsing the Content View there are significant problems for any such interpretation. I further argue that given the problems associated with attributing the Content View to Kant, interpreters should instead consider him as endorsing a form of acquaintance theory. Though perceptual acquaintance is controversial (...) in itself and in attribution to Kant, it promises to make sense of central claims within his critical philosophy. (shrink)

The notion of ‘power of judgement’ in the title of Kant'sCritique of the Power of Judgementis commonly taken to refer to a cognitive power inclusive of both determining judgement and reflecting judgement. I argue, first, that this seemingly innocuous view is in conflict both with the textual fact that Kant attempts a Critical justification of the reflecting power of judgement – only – and with the systematic impossibility of a transcendentally grounded determining power of judgement. The conventional response to these (...) difficulties is to point out that, Kant's systematic ambitions in the thirdCritiquenotwithstanding, reflection, qua concept-forming synthesis, is too closely tied to determination to be a cognitive power in its own right. I argue, second, that this response is question-begging, since the notion of reflection it employs is not only not one central to the thirdCritiquebut one antecedently tied to the understanding. I argue, third, that Kant's discussion, in the pivotal § § 76–7, of our cognitive relation to sensible particularity addresses an epistemic problem present (but not raised) in theCritique of Pure Reason. This is the problem of the synthesizability, qua absolute unity, of unsynthesized intuitions. Solving this problem requires Critical justification of a principle of reflection. It follows that Kant's systematic ambitions in the thirdCritiqueare appropriate. Given the problem Kant seeks to address, he must offer what he takes himself to be offering: aCritique of the(Reflecting)Power of Judgement. (shrink)

Kant's notion of ‘discipline’ has received considerable attention from scholars of his philosophy of education, but its role in his theoretical philosophy has been largely ignored. This omission is surprising since his discussion of discipline in the first Critique is not only more extensive and expansive in scope than his other discussions but also predates them. The goal of this essay is to provide a comprehensive reading of the Discipline that emphasizes its systematic importance in the first Critique. I argue (...) that its goal is to establish a set of rules for the use of pure reason that, if followed, will mitigate and perhaps even eliminate our tendency to make judgments about supersensible objects. Since Kant's justification for these rules relies crucially on claims he has defended in the Doctrine of Elements, I argue further that, far from being a dispensable part of the Critique as commentators have tended to claim, the Discipline is, in fact, the culmination of Kant's critique of metaphysics. (shrink)

Hume’s account of causation is often regarded a challenge Kant must overcome if the Critical philosophy is to be successful. But from Kant’s time to the present, Hume’s denial of our ability to cognize supersensible objects, a denial that relies heavily on his account of causation, has also been regarded as a forerunner to Kant’s critique of metaphysics. After identifying reasons for rejecting Wayne Waxman’s recent account of Kant’s debt to Hume, I present my own, more modest account of this (...) debt, an account that seeks to unite the two very different pictures of Kant’s relationship to Hume sketched above. (shrink)

Dennis Schulting offers a thoroughgoing, analytic account of the first half of the Transcendental Deduction of the Categories in the B-edition of Kant's Critique of Pure Reason that is different from existing interpretations in at least one important aspect: its central claim is that each of the 12 categories is wholly derivable from the principle of apperception, which goes against the current view that the Deduction is not a proof in a strict philosophical sense and the standard reading that in (...) the Deduction Kant only gives an account of the global applicability of the categories to experience. This novel approach enables a reappraisal of Kant's controversial claim that transcendental self-consciousness is not only a necessary condition of objective experience but also sufficient for it. The book provides an extensive analysis of Kant's theory of transcendental apperception and also explains why the argument of the Transcendental Deduction is both a regressive and a progressive argument. (shrink)

I present an argument for an interpretation of Kant's views on the nature of the ‘content [Inhalt]’ of ‘cognition [Erkenntnis]’. In contrast to one of the longest standing interpretations of Kant's views on cognitive content, which ascribes to Kant a straightforwardly psychologistic understanding of content, and in contrast as well to the more recently influential reading of Kant put forward by McDowell and others, according to which Kant embraces a version of Russellianism, I argue that Kant's views on this topic (...) are of a much more Fregean bent than has traditionally been admitted or appreciated. I conclude by providing a sketch of how a better grasp of Kant's views on cognitive content in general can help bring into sharper relief what is, and what is not, at stake in the recent debates over whether Kant accepts a particular kind of cognitive content—namely, non-conceptual content. (shrink)

This paper gives an interpretation of Kant's argument for transcendental idealism in the Transcendental Aesthetic. I argue against a common way of reading this argument, which sees Kant as arguing that substantive a priori claims about mind-independent reality would be unintelligible because we cannot explain the source of their justification. I argue that Kant's concern with how synthetic a priori propositions are possible is not a concern with the source of their justification, but with how they can have objects. I (...) argue that Kant's notion of intuition needs to be understood as a kind of representation which involves the presence to consciousness of the object it represents, and that this means that a priori intuition cannot present us with a mind-independent feature of reality. (shrink)

For Kant, the human cognitive faculty has two sub-faculties: sensibility and the understanding. Each has pure forms which are necessary to us as humans: space and time for sensibility; the categories for the understanding. But Kant is careful to leave open the possibility of there being creatures like us, with both sensibility and understanding, who nevertheless have different pure forms of sensibility. They would be finite rational beings and discursive cognizers. But they would not be human. And this raises a (...) question about the pure forms of the understanding. Does Kant leave open the possibility of discursive cognizers who have different categories? Even if other discursive cognizers might not sense like us, must they at least think like us? We argue that textual and systematic considerations do not determine the answers to these questions and examine whether Kant thinks that the issue cannot be decided. Consideration of his wider views on the nature and limits of our knowledge of mind shows that Kant could indeed remain neutral on the issue but that the exact form his neutrality can take is subject to unexpected constraints. The result would be an important difference between what Kant says about discursive cognizers with other forms of sensibility and what he is in a position to say about discursive cognizers with other forms of understanding. Kantian humility here takes on a distinctive character. (shrink)

This paper analyses the features of Kant’s transcendental philosophy, which Kant himself described as transcendental idealism. On the one hand, Kant’s transcendentalism rests on the distinction between things in themselves and appearances. On the other hand, our ‘mode of cognition’ [Critique, B25] cognition is representative in that is based on representations — subjective and objective ones. A synthesis of the above considerations suggests that Kant’s transcendentalism rests on the conceptual triad “[objective] object — appearance — and [mental] representation “. Kant’s (...) transcendentalism is impossible without the ‘premise’ of appearance. The correct interpretation of Kant’s transcendental philosophy should keep the double difference of appearance both from thing–in–itself and representation. In this transcendental triad, the Kantian appearance has an intermediate status since it is located between objective things and subjective representations. However, the conceptual status of the appearance needs to be clarified, since Kant himself does not give a clear answer to this question, and at present there are several interpretations, differing primarily in the definition of the concept of the appearance. For me, appearance can be correlated with objective–objectual representation. It would be unwise to identify appearance with thing in itself, which was characteristic of pre–Kantian philosophy, or appearance with representation, which was the case in phenomenalist interpretations of transcendental idealism à la Berkley. The Kantian appearance, as emphasised in BXXVII of his Critique, is an appearance of an object, which — although implicitly — suggests a semantic relationship of reference. In this case, the appearance is not an object, but just ‘a designation of an object’ [Critique, B235]. Appearance is impossible without what appears in it. This paper puts forward a number of arguments in favour of the objectual status of Kant’s concept of appearance. (shrink)

Does epistemology collapse for lack of resources other than logic, conceptual analysis and descriptions of one’s own apparent experiences, thoughts and beliefs? No, but understanding how and why not requires, Kant noted, a ‘changed method of thinking’. Some of these methodological changes are summarised in §2 in order to identify a philosophical role for thought experiments to help identify logically contingent, though cognitively fundamental capacities and circumstances necessary to human thought, experience and knowledge. As Kant also noted, experiments are only (...) informative in response to posing the right question, indeed: the right kind of question. Accordingly, preparations for these epistemological thought experiments fill half of this chapter. The second half, examines three such thought experiments, variously developed by Kant, Hegel, C. I. Lewis, Austin, Wittgenstein and F. L. Will. (shrink)

A tese de que o conceito espinosista de ideia de afecção, introduzido na Ética, expressa o sentido mais preciso do que seja, para o autor, o conceito de ideia da imaginação. Este texto pretende problematizar essa leitura, procurando fornecer subsídios para a hipótese de que ela não é nem inequivocamente corroborada pelo texto da Ética, nem exigida pela doutrina aí apresentada. -/- It is widely accepted by scholars that Spinoza’s concept of idea of affection, introduced in the Ethics, states his (...) notion of the idea of imagination. In this paper I address this reading, claiming that it is not either unequivocally corroborated by the text of the Ethics, or required by the doctrine developed there. (shrink)

The aim of this paper is to apply Charles S. Peirce's pragmatic method to establishing if proponents of transcendental arguments could hold the conclusions of their arguments to be fallibly known. I will thus propose a pragmatic clarification of the concepts of a priority, necessity, and infallibility in order to ascertain if these concepts are unavoidably related or not. I will argue that an a priori knowable necessary proposition is not in principle indubitable, whereas a proposition infallibly known is so. (...) Finally, I will apply these reflections to transcendental philosophy. (shrink)

My contribution to a book symposium on Graham’s commentary on Kant’s Critique of Pure Reason, sponsored by the North American and the UK Kant Societies, held in conjunction with the Central Division Meeting of the American Philosophical Association, Chicago, 20 February 2009. Comments also delivered by Adrian Moore, Gary Banham, Jill Buroker and Manfred Kuehn, with relplies by Graham Bird.

While the debate about whether Kant's idealism requires a ‘Two Worlds’ or ‘Two Aspect’ interpretation has reached a seeming impasse, I argue that the account of intelligible possession found in the ‘Doctrine of Right’ provides novel and compelling evidence in favour of an epistemic ‘Two Aspect’ reading of Kant's position.

RÉSUMÉ : Afin de circonscrire lescepticisme qui lui paraît miner l'entreprise métaphysique des Lumières, il est apparu nécessaire au Kant de la période critique de répondre à trois formes de scepticisme : au scepticisme baylien, qui s'interroge sur la capacité de la raison à parvenir à définir une vérité en rapport avec les idées de cette même raison; au scepticisme humien, ce qui le conduit à distinguer la question soulevée par Hume de son scepticisme pour parvenir à dégager la possibilité (...) de jugements synthétiques a priori; et au scepticisme cartésien, qui met en jeu le lien entre concepts empiriques et choses du monde extérieur. L,'analyse du traitement qu'il en propose montre que le scepticisme joue un rôle fondamental au sein de l'entreprise critique si bien qu'il peut être considéré comme un allié possible afin de rabattre les prétentions du dogmatisme idéaliste.ABSTRACT: In his critical period, Kant thought that scepticism was a threat to the metaphysical enterprise of Enlightenment. He consequently tried to tackle three of its species: Baylean scepticism, which doubts that reason could establish any truth concerning its ideas; Humean scepticism, which must be distinguished from Hume's formulation of the problem if we want to show that synthetic a priori judgements are possible; and Cartesian scepticism, which puts in doubt the reference of empirical concepts to things in the external world. Kant's treatment reveals the fundamental role played by scepticism in his critical enterprise not only as a tripIe challenge to the critical project, but also as an ally against idealist dogmatism. (shrink)

Standard interpretations of Kant’s transcendental idealism take it as a commitment to the view that the objects of cognition are structured or made by conditions imposed by the mind, and therefore to what Van Cleve calls “honest-to-God idealism”. Against this view, many more recent investigations of Kant’s theory of representation and cognitive significance have been able to show that Kant is committed to a certain form of Mental Content Externalism, and therefore to the realist view that the objects involved in (...) experience and empirical knowledge are mind-independent particulars. Some of these recent interpreters have taken this result to demonstrate an internal incompatibility between Kant‘s transcendental idealism and his own model of cognitive content and the environmental conditions of empirical knowledge. Against this suggestion, this article argues that, while Kant’s theory of content is indeed best construed as externalist, an adequately adjusted form of transcendental idealism is not only compatible with this externalism, but in fact supports it. More generally, the article develops the position that mental content externalism cannot force the adoption of metaphysical realism. (shrink)

ABSTRACT One of the core issues where interpreters of Kant disagree concerns his alleged Noumenalism—the claim that the objects of our experience, which are in space and time, are underpinned by entities that are not spatio-temporal and that non-spatio-temporally cause our representations of empirical objects. Although there is much textual evidence in favour of Noumenalism, non-Noumenalists have also gathered a significant number of philosophical and exegetical challenges to such a reading of Kant. I present a novel way of understanding the (...) Noumenalist view, which characterises the distinction between appearances and things in themselves as the distinction between referents and truthmakers. I show that, on this interpretation of Kant, the most pressing problems for the Noumenalist reading are primarily based on equivocations between features of reference and features of truthmaking. (shrink)

The interpretation of Kant's Critical philosophy as a version of traditional idealism has a long history. In spite of Kant's and his commentators’ various attempts to distinguish between traditional and transcendental idealism, his philosophy continues to be construed as committed to various features usually associated with the traditional idealist project. As a result, most often, the accusation is that his Critical philosophy makes too strong metaphysical and epistemological claims.In his The Revolutionary Kant, Graham Bird engages in a systematic and thorough (...) evaluation of the traditionalist interpretation, as part of perhaps the most comprehensive and compelling defence of a revolutionary reading of Kant's thought. In the third part of this special issue, the exchanges between, on the one hand, Graham Bird and, on the other, Gary Banham, Gordon Brittan, Manfred Kuehn, Adrian Moore and Kenneth Westphal focus on specific aspects of Bird's interpretation of Kant's first Critique. More exactly, the emphasis is on specific aspects of Bird's interpretation of the Introduction, Analytic of Principles and Transcendental Dialectic of Kant's first Critique.The second part of the special issue is devoted to discussions of particular topics in Bird's construal of the remaining significant parts of the first Critique, namely, of the Transcendental Aesthetic and the Analytic of Concepts. Written by Sorin Baiasu and Michelle Grier, these articles examine specific issues in these two remaining parts of the Critique, from the perspective of the debate between the traditionalist and revolutionary interpretation. The special issue begins with an Introduction by the guest co-editors. This provides a summary of the exchanges between Bird and his critics, with a particular focus on the debates stemming from the differences between traditional and revolutionary interpretations of Kant. (shrink)

In this Paper I interpret Charles S. Peirce’s method of prescision as a transcendental method. In order to do so, I argue that Peirce’s pragmatism can be interpreted in a transcendental light only if we use a non‐justificatory understanding of transcendental philosophy. I show how Peirce’s prescision is similar to some abstracting procedure that Immanuel Kant used in his Critique of Pure Reason. Prescision abstracts from experience and thought in general those elements without which such experience and thought would be (...) unaccountable. Similarly, in the Aesthetics, Kant isolated the a priori forms of intuition by showing how they could be abstracted from experience in general, while experience in general cannot be thought without them. However, if Peirce’s and Kant’s methods are similar in this respect, they reached very different conclusions. (shrink)

The interpretation of Kant's Critical philosophy as a version of traditional idealism has a long history. In spite of Kant's and his commentators’ various attempts to distinguish between traditional and transcendental idealism, his philosophy continues to be construed as committed to various features usually associated with the traditional idealist project. As a result, most often, the accusation is that his Critical philosophy makes too strong metaphysical and epistemological claims.In his The Revolutionary Kant, Graham Bird engages in a systematic and thorough (...) evaluation of the traditionalist interpretation, as part of perhaps the most comprehensive and compelling defence of a revolutionary reading of Kant's thought. In the third part of this special issue, the exchanges between, on the one hand, Graham Bird and, on the other, Gary Banham, Gordon Brittan, Manfred Kuehn, Adrian Moore and Kenneth Westphal focus on specific aspects of Bird's interpretation of Kant's first Critique. More exactly, the emphasis is on specific aspects of Bird's interpretation of the Introduction, Analytic of Principles and Transcendental Dialectic of Kant's first Critique.The second part of the special issue is devoted to discussions of particular topics in Bird's construal of the remaining significant parts of the first Critique, namely, of the Transcendental Aesthetic and the Analytic of Concepts. Written by Sorin Baiasu and Michelle Grier, these articles examine specific issues in these two remaining parts of the Critique, from the perspective of the debate between the traditionalist and revolutionary interpretation. The special issue begins with an Introduction by the guest co-editors. This provides a summary of the exchanges between Bird and his critics, with a particular focus on the debates stemming from the differences between traditional and revolutionary interpretations of Kant. (shrink)

The interpretation of Kant's Critical philosophy as a version of traditional idealism has a long history. In spite of Kant's and his commentators’ various attempts to distinguish between traditional and transcendental idealism, his philosophy continues to be construed as committed (whether explicitly or implicitly and whether consistently or inconsistently) to various features usually associated with the traditional idealist project. As a result, most often, the accusation is that his Critical philosophy makes too strong metaphysical and epistemological claims.

Kant and Sartre are two of the most significant figures in modern philosophy, and yet there has, until very recently, been little comparative research undertaken on them. Despite dealing with many shared philosophical issues, they have traditionally been taken to be too opposed to each other to render any search for possible parallels between their works a useful enterprise. Indeed, Sartre is often taken to be one of Kant’s most vocal critics in the literature, and as rather indebted to other (...) major figures, such as Husserl and Heidegger. As a consequence, often, where comparative analysis has been done upon Kant and Sartre, the emphasis has been on their differences, rather than on their similarities. However, as recent research has begun to show, the story is not that straightforward and there is much to be explored with regard to parallels between Kant and Sartre. Baiasu has characterised Sartre’s relation to Kant as one of an “anxiety of influence” – Sartre desires to explicitly distance himself from Kant, but this obscures some deeper underlying parallels between them1. Such parallels can form a foundation for productive dialogue, more widely, between the schools of Kantian “Critical philosophy” and existentialism2. (shrink)

In this chapter, I show that there is at least one crucial, non-short, argument, which does not involve arguments about spatiotemporality, why Kant’s subjectivism about the possibility of knowledge, argued in the Transcendental Deduction, must lead to idealism. This has to do with the fact that given the implications of the discursivity thesis, namely, that the domain of possible determination of objects is characterised by limitation, judgements of experience can never reach the completely determined individual, i.e. the thing in itself (...) or the unlimited real, but only objects as objects of possible experience. As such, it can be shown by reference to a key argument from Kant, that Hegel’s famous criticism that Kant is not licensed, on the basis of his core arguments concerning the original-synthetic unity of apperception, to restrict our knowledge to appearances, is mistaken on purely systematic grounds. More specifically, I argue that idealism follows already from the constraints that the use of the categories, in particular the categories of quality, places on the very conceivability of things in themselves. My claim is that, although it is not only possible but also necessary to think things in themselves, it does not follow that by merely thinking them we have a full grasp of the nature of things in themselves, as some important commentators claim we have. We must therefore distinguish between two kinds of conceiving of things in themselves: conceiving in the standard sense of ‘forming the notion of’, and conceiving in the narrow sense of ‘having a determinate intellectual grasp’. So although we must be able notionally to think things in themselves, as the grounds of their appearances, we cannot even conceive, through pure concepts, of how they are in themselves in any determinate, even if merely intellectual, sense. To put it differently, we cannot have a positive conception of things in themselves (this is in line with Kant’s distinction between noumena in the negative and positive senses; cf. B307–9). For support, I resort to a much overlooked chapter in the Critique, concerning the transcendental Ideal, where Kant discusses what it is for a thing to be a thing in itself proper, namely, something that is thoroughly determined. This concerns the real ontological conditions of things, which are not satisfied by the modal categories alone, namely, their existence conditions. I claim that the chief reason why, given Kant’s view of determinative judgement, we cannot determine a thing in itself is because of two connected reasons: (1) a thing in itself is already fully determined and therefore not further determinable and (2) we cannot possibly determine all of the thing’s possible determinations. In this context, I also discuss the notion of material (not: empirical) synthesis—of which Kant speaks in the chapter on the transcendental Ideal—which must be presupposed as the ground of the formal a priori synthesis that grounds possible experience. This material synthesis, which is an idea of reason that defines a thing as thoroughly determined with regard to all of its possible predicates and has mere regulative status, can by implication not be determined by the forms of the understanding, which synthesise only a limited set of predicates. As a result, given this definition of ‘thing in itself’, any object (appearance) as at best44 a limited set of determinations of the thing can never be numerically identical to the thing in itself as thoroughly determined individual. This undercuts a standard assumption about the identity relation between appearances and things in themselves in many contemporary interpretations of Kant’s transcendental idealism. (shrink)