The idea of organizing an event which would focus on Graham Bird's The Revolutionary Kant (TRK) (2006)Footnote 1 was in a sense obvious. Bird's opus was one of the very few single-authored comprehensive commentaries on Kant's first Critique published during the last few decades (in fact, to our knowledge, the only one).Footnote 2 What other response would have been more appropriate to this new publication than an event gathering scholars from both the US and the UK in order to pursue critical discussion of this important work?

The idea of organizing a session devoted entirely to TRK first emerged during a workshop organized by the Kantian Standing Group of the European Consortium for Political Research in Pisa.Footnote 3 Soon thereafter, the Author Meets Critics session on Bird's book started to become a reality with both the UK Kant Society and the North American Kant Society supporting its organization. The session took place at the 2009 American Philosophical Association Central Division Meeting in Chicago on 19 February 2009, where Graham Bird was also awarded the Mary Gregor Prize by the North American Kant Society.

The articles by Gary Banham, Manfred Kuehn, Adrian W. Moore and Kenneth Westphal, as well as Bird's responses, are revised versions of the papers presented then. Gordon Brittan's article and Bird's response are the outcome of subsequent discussion. Articles touch on issues which can be found mainly in the Introduction, Analytic of Principles and the Transcendental Dialectic of the first Critique. We have therefore added at the end of this Introduction two short articles on issues in Bird's discussion of the Transcendental Aesthetic and the Analytic of Concepts. In this way, we can say that most parts of the first Critique and of Bird's commentary are at least touched on in this special issue devoted to his book.

This Introduction will centre on the initial exchange between Bird and his criticsFootnote 4 and, in particular, on one of the central distinctions of Bird's book, that between traditionalist and revolutionary approaches to Kant. This is a theme which runs through the exchange and also informs our subsequent discussion of Bird's treatment of the Transcendental Aesthetic and the Analytic of Concepts.

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With respect to Bird's account of the Analogies of Experience, Gary Banham (‘The Status of the Principles of the Analogies’) argues against what he takes to be Bird's rather ‘minimalist’ or ‘weak’ interpretation of the Analogies. The debate between Banham and Bird gets its momentum from the different ways in which the Second Analogy is to be construed. On more ‘traditionalist’ interpretations, the Second Analogy has often been taken to defend and justify not merely the very general causal law (‘Every event has some cause’), but additionally, to demonstrate that ‘the same causes produce (uniformly) the same effects’.

To this extent, some have taken Kant to be responding to a number of problems generated by Hume's well-known scepticism and his critique of both the causal law in general, but also of inductive generalizations, as well as particular claims about specific causal connections. And on this matter, many have gone so far as to read Kant's arguments in the Second Analogy as attempts to justify the uniformity principle (the claim that nature must behave in a uniform or regular way). Such interpretations constitute, on Bird's view, a ‘traditional’ interpretation of Kant.

In contrast to these traditional interpretations, Bird argues that the principle of the Second Analogy (which he takes to be quite simply the ‘general causal principle’) does not, and was not intended by Kant to, entail by itself alone any further principle of the uniformity of nature. Nor does it propose to justify any more concrete principle demonstrating the truth of very specific causal laws. In short, Bird rejects the general contention that Kant's aim in the Second Analogy was to refute Humean scepticism about induction. Rather, on Bird's view, the Second Analogy is designed to demonstrate a ‘non-analytic’ but nevertheless necessary connection between the concepts of a cause and an event. In this, Bird stresses the necessary connection in question not as one ‘between events, but within an event between different states of some substance’. To this extent, Bird is willing to accept and defend what has come to be called a more ‘weak’, that is to say, a more modest, interpretation of the aim of Kant's argument.

Banham seeks to show that Bird's position is problematic insofar as it limits our discussion to a very ‘abstract and austere’ reconstruction of the argument of the Second Analogy. Briefly, Banham's response is that Bird's understanding of the argument fails to appreciate fully the relation between the Second and Third Analogies. According to Banham, the universal laws expressed in the Second and Third Analogies ‘come together in a picture of a dynamical world-whole in which there is continuous action of causality between mutually dependent substances’. Taken together, the Analogies are thus said to ‘point in the direction of universal determinism’.

Moreover, according to Banham, the causal thesis of the Second Analogy, given its tight connection with the thesis of the Third Analogy, provides the basis for the arguments in favour of the kind of causality (universal determinism) later under consideration in the Third Antinomy. Bird, however, denies that the causal principle announced in the Second Analogy (even granting its relation to the other Analogies) bears such a tight connection to the deterministic position defended in the antithesis argument of the Third Antinomy, although he does agree that the general causal principle defended in the Second Analogy invites and encourages us to conceive of such determinism. The debate between Banham and Bird is thus carried over into a discussion about the different roles played by the regulative principles of reason, as opposed to the constitutive principles of the understanding.

With respect to the distinction between the regulative principles of reason and the constitutive principles of the understanding, on Bird's account, the universal determinism at issue in the Third Antinomy may well be allowed, but only if it is understood as a regulative principle which enjoins us to seek further conditions or causes. Such regulative principles are thus taken to be different in aim and scope from the constitutive principles of the Analogies which make experience possible. Banham, on the other hand, holds that Bird's account does not and cannot articulate the ‘way in which specific laws of nature relate to the transcendental principles of the Analogies’, and he thus argues that the ‘regulative’ principles of reason also play an essential role in making experience possible, and securing a criterion of empirical truth.

In his paper (‘Graham Bird, The Revolutionary Kant: Introduction’), Gordon Brittan focuses on Bird's discussion of one of the central problems of the first Critique, the problem of the possibility of synthetic a priori judgements. One question Brittan raises is whether the two distinctions implicit here (a priori/a posteriori and analytic/synthetic) are sufficiently different to make the notion of a synthetic a priori judgement non-contradictory. This challenge comes, in fact, from those philosophers (mainly empiricists) who claim that all a priori judgements are analytic and all analytic judgements a priori. If extensionally the class of ‘a priori’ judgements and that of ‘analytic’ judgements are the same, then synthetic a priori judgements would seem impossible.

There is, however, an even more serious question on this topic. The issue is no longer whether the two distinctions are sufficiently different, but whether we can draw any distinction at all. Brittan takes the second part of Bird's response to be more significant. Thus, in Bird's view, even if analytic and a priori judgements are co-extensive, it does not follow that the distinction between them cannot be drawn intensionally. Yet Brittan thinks this is a particularly problematic aspect of Bird's account.

According to Brittan, Bird characterizes the analytic/synthetic distinction in terms of types of truths. By contrast, Kant seems to claim something quite distinct, namely, that truth is the agreement of cognition with its object and that an analytic judgement leaves undecided whether the concept even has any relation to objects. This suggests the analytic/synthetic distinction cannot be drawn in terms of types of truth.

One implication is that concept analysis cannot determine reference, a claim Brittan thinks sets Kant apart from Leibniz. Moreover, this claim shows that, in spite of all the differences between Kripke and Kant, there is also a significant point of intersection that Bird misses in his discussion of Kripke. In Brittan's account, Kripke's notion of rigid designation is formulated as an answer to descriptive theories of reference, and Kant's question in his 1772 letter to Herz is precisely a question about the possibility for singular terms, particularly those without empirical elements, to refer to objects that exist independently from our conception and perception of them.

For Kripke, rigid designation is a feature of genuinely singular terms, terms which refer to the same individual in all possible worlds. Kant is concerned with reference, but he disagrees there are such singular terms – intuitions are always required. Like Kripke, however, he tries to identify the conditions with respect to which designation is possible.

In response, Bird expresses two related worries. First, he thinks in Kant's theory there is no comparable effort to provide a conceptual framework able to distinguish between reference in some and reference in all possible worlds. Secondly, Bird finds Brittan's claim that both Kant and Kripke attempt to provide accounts of objective reference more likely to distort Kant's view than to illuminate it. This is because, as presented by Brittan, the project of an account of objective reference is usually pursued in the attempt to avoid Kant's so-called psychologism (the allocation of transcendental elements of experience to one or another psychological faculty). Yet Bird thinks this distinctive feature of Kant's account helps in fact as a counterweight to a twentieth-century overemphasis on language.

Brittan also formulates some objections to Bird's understanding of the a priori. One of these concerns the definition of the a priori as that which does not require presented experience. Yet, Brittan says, while a feature of a priori judgements is their necessity and universality, it is difficult to understand how the negative characterization of such judgements as not requiring presented experience can lead to necessity and universality.

In reply, Bird draws a distinction between transcendental and synthetic a priori judgements (a distinction used also in his reply to Westphal). He thinks that the former are necessary conditions which make experience possible and they are indeed synthetic a priori. Yet, he thinks synthetic a priori judgements need not be transcendental, that is, experience-enabling. In the Introduction to the Critique, Bird says, Kant is indeed concerned to define (what Bird calls) the ‘analytic apparatus’ of his Critical philosophy (for instance, a priori/a posteriori and synthetic/analytic distinctions). But this enterprise is quite distinct from the argument Kant talks about in the Analytic of Principles, where the focus is on transcendental principles.

What is more, the distinction between synthetic a priori and transcendental judgements suggests also that transcendental principles are those which are necessary and universal insofar as they make experience possible; by contrast, synthetic a priori judgements need not be necessary and universal in this sense. Finally, in Bird's account, classifying a judgement as a priori does not automatically establish its truth, since we can know judgements to be false a priori. To establish the truth of an a priori judgement one needs a proof which depends on the appropriate kind of warrant.

We said that the debate between traditionalist and revolutionary interpretations of Kant's work is the guiding thread that we are following in this introductory piece. But how is this reflected by Brittan's contribution? The answer is not immediately clear as the distinction is not explicitly mentioned or addressed in his text. Brittan's understanding of Kant's project as that of providing an account of objective reference is informed by the linguistic turn and, as Bird suggests, is part of an attempt to regard Kant's epistemology as a normative epistemology in need of justification for its psychologistic assumptions. From this perspective, Brittan's reading of Kant seems to advance or give indirect support to the traditionalist interpretation.

Manfred Kuehn (‘How, or Why, do we Come to Think of a World of Things in Themselves?’) focuses directly on Bird's distinction between traditionalist and revolutionary accounts of Kant's first Critique. On Kuehn's account, the distinction is too exclusionary to be useful. He discusses in particular Kant's distinction between appearances and things in themselves, and argues against Bird's central claim that the two main interpretations of this distinction, the two-world and the two-aspect accounts, are thoroughly misleading and should be given up. To abandon these and in particular the first one, Kuehn argues, means to give up on a significant part of Kant's work too.

The first standard interpretation regards appearances and things in themselves as two distinct worlds. To this view, Bird objects that it implies a commitment to the existence and knowledge of these worlds, although Kant denies any such commitment to things in themselves. Secondly, Bird adds, even without the assumption of such a commitment why would we need reference to a possible world of which in principle we can have no knowledge?

Bird's own interpretation refers to two points of view or standpoints, rather than to two worlds, and is supposed to avoid the problems of the two-world view and to provide a more accurate interpretation. For instance, Bird thinks that, in Kant's view, things in themselves are only correlates of appearances, since the only objects we can identify and know are the objects of experience. In fact, according to Kuehn, Kant justifies the distinction between appearances and things in themselves by introducing a principle according to which experience cannot be all there is and experience cannot set a boundary for itself. A boundary can only be set by reason from beyond the realm of experience.

As set from a realm beyond that of experience, this so-called ‘boundary principle’ is related to the transcendental distinction between appearances and things in themselves and to the limit of the sensible world. Kant's discussion of things in themselves, therefore, is not merely meant to indicate that we can have no knowledge of them, but also to assert that the objects of experience, the things we perceive, are precisely not the things in themselves, which are non-spatial and non-temporal, and which should belong to a realm beyond what is merely sensed.

Hence, for Kant, the two-standpoint account is quite closely connected with the two-world account. The two-world account should not be rejected so quickly. On the contrary, the more appropriate task would be that of clarifying the relationship between these accounts. Only in this way, Kuehn claims, can we make sense of those passages in Kant (the first Critique, but also the Prolegomena, the Groundwork and the second Critique) where he seems to talk precisely about two worlds.

In addition to this debate concerning how to use the distinction, a second debate between Kuehn and Bird centres on the question of whether the distinction is in fact justified. Bird's answer is an appeal to Kant's claim that we must be able to think of the objects of experience as things in themselves, since otherwise we end up with the absurd conclusion that there can be appearances without anything that appears. This necessity of the talk about things in themselves, however, does not commit Kant to their existence, but to their conceivability. The concept of such things is necessarily implied as a correlate of objects of experience.

Kuehn finds Bird's argument here quite weak. The argument that without things in themselves talk about appearances would be absurd (what Kuehn calls the ‘absurdity or inconceivability claim’) is open to various objections. First, Kant thinks that, as such, talk about appearances is innocuous – in our everyday experience, certain things appear to be in a certain way and then turn out to be different. Moreover, Kuehn adds, perspectival talk is equally innocuous: a circle may appear as an ellipse from a certain perspective. Furthermore, physicists of the early modern period tried to take a step further than common sense. They thought models of physical objects should not depend on the point of view of the modeller or observer, so descriptions of such objects should be invariant with rotations in space and differences in time. This perspective-invariant scientific ideal seems also unproblematic: the perspective-invariant description refers to the thing as it is independently from spatial position and temporal location of the observer, whereas the perspective-affected description would provide an appearance.

Kant's distinction between appearances and things in themselves, Kuehn continues, is however deeper. Kant wants to consider the perspective-invariant thing as an appearance and to distinguish it from things in themselves in a transcendental sense. This, Kuehn says, raises more acutely the problem of the necessity of a thing in itself in the transcendental sense. In the empirical sense, a thing in itself is the empirical object we get to know and distinguish from mere appearances. But in the transcendental sense, the object remains in principle unknown – so why do we need to postulate this thing in itself? Even if it is correct that, in the transcendental sense, we can only speak of appearances when we distinguish them from things in themselves, the question is why we would need to engage in transcendental talk to begin with.

In his response, Bird emphasizes the relation between appearances and sensibility, on the one hand, and between things in themselves and understanding, on the other. Since for Kant, Bird argues, appearances are indeterminate objects of intuition, the obvious question is how to explain the differentiation into objects which appearances are appearances of. The answer is of course that the understanding's concepts and principles introduce this differentiation. As determinate merely by concepts, these things are independent from sensibility and accessed through understanding or reason. This is one direction in which the question of differentiation can be taken.

In a different sense, the question can be answered by emphasizing that objects are accessed through sensibility and differentiated through the conceptual resources of the understanding. Furthermore, Bird adds, Kant stresses that while we may colloquially talk about things we experience as actually existing, and thereby in using ‘existence’ assume independence from sensibility, in a philosophical context we cannot simply claim actual existence. This leads inevitably to the idea of things which are conceivable, but unknowable.

One conclusion is that the justification for the talk about things in themselves is not necessarily related to the absurdity claim, but can be rephrased on the basis of the distinction between sensibility and understanding, a distinction which leads to the concept of things in themselves. A second conclusion concerns the notion of appearance and its link to sensibility. According to Bird, what is important is not so much Kant's choice of this term, but the fact that he uses it to distinguish between indeterminate and differentiated objects, as well as between colloquial and philosophical contexts of its use.

Bird acknowledges that Kant talks about two worlds and also that he does allow a more positive appeal to things in themselves beyond its negative and therapeutic value. He notes that Kant does assert a more determinate practical knowledge of freedom through the moral law, yet he thinks Kant is not thereby committed to any theoretical insight with regard to the possibility of this freedom.

The objective reality of the idea of a moral law, Kant says, does not refer to an object of an intelligible intuition, but it refers to the sensible world viewed as being an object of pure reason in its practical employment. Hence, Bird claims, Kant's intention is not to separate two worlds, but to integrate them better, as suggested by the Third Antinomy, where Kant tries to reconcile our moral, intelligible and our sensory, material judgements. The commitment this implies is similar, Bird says, to that we have in theoretical philosophy when we need to introduce schemata in order to realize unschematized categories in immanent experience. In the case of morality, we also have an additional interest in appealing to a supersensible freedom as a defence against determinism.

A. W. Moore (‘Bird on Kant's Mathematical Antinomies’) also questions some of the ‘revolutionary’ aspects of Bird's view. Moore focuses his discussion on the mathematical Antinomies. In particular he takes issue with what he considers to be Bird's contention that we cannot settle issues about the ‘physical universe’ by pure reason. On Moore's view, even granting that Kant denies that we can ever achieve a priori knowledge of transcendent objects, pure reason nevertheless has a significant role to play in adducing knowledge about the physical universe. Moore cites both mathematics and the Analogies as examples wherein pure reason can and does yield knowledge about the physical universe.

Another example, according to Moore, would be Kant's ostensible claim that we can know that there must be something unconditioned which corresponds to the conditioned available to us in the physical universe (under the proviso that this unconditioned cannot be itself physical). Citing the dynamical antinomies as an example, Moore contends that Kant is utterly committed not only to this claim but also to a view according to which we do have some knowledge of things in themselves, including knowledge of their existence. In the dynamical antinomies, for example, the dispute is resolved by appealing to the transcendental distinction between appearances and things in themselves. The thesis positions and the antithesis positions may both be allowed to stand, providing that we properly distinguish the domain within which the claims hold, to wit, either the domain of things in themselves or that of the ‘physical universe’.

The fact that the thesis arguments of the dynamical Antinomies can only hold for ‘things in themselves’, which we cannot determinately know, makes it clear that pure reason cannot ‘settle’ this particular issue ‘about the character of the physical universe’. Moore's contention is that it is only and particularly in the case of the mathematical antinomies that this strategy does not succeed. According to Moore, the mathematical antinomies cannot be resolved by appeal to the transcendental distinction between appearances and things in themselves precisely because in these cases the error involves a ‘confused amalgam of an idea of reason with some concept that can be applied only to objects of possible experience’.

In Moore's words, unlike the conflicts in the dynamical antinomies (which are, at least ‘well-conceived’, if problematic), the vexing problems which concern the mathematical antinomies are entirely ‘ill conceived’. They thus have no answer. But this does not entail that for Kant there is no answer issuing from pure reason relating to other features of the physical universe. Indeed, insofar as Kant claims to demonstrate that in the cases of the mathematical antinomies, both positions are (and must be) false, he is committed to the claim that pure reason can resolve the conflict, and it can do so by pointing out that the underlying presupposition to these debates (that the physical universe exists as a whole and is all-encompassing) is incoherent. On Moore's view, this demonstrates (contra Bird) the ‘decidability’ of the mathematical antinomies by pure reason.

Whereas Moore contends that the mathematical antinomies cannot be resolved by any constructive appeal to the appearances/things in themselves distinction, Bird contends that these, just as with the dynamical antinomies, do get ‘resolved’ by an appeal to this distinction. More specifically, he argues that Kant's philosophy allows us (those who have been instructed in the transcendental epistemology) to resolve the issues under consideration, issues which (apart from Kant's transcendental epistemology) would remain unsettled.

Moreover, in response to Moore, Bird argues that his claim is not that pure a priori reasoning has no role to play in knowledge of the ‘physical universe’, but rather that pure (a priori) reasoning alone cannot give us knowledge about the physical universe. To attempt to use pure reason alone in this regard is tantamount to deploying the concepts and principles of transcendental logic as an actual ‘organon’ for knowledge.

In his piece (‘Comments on Graham Bird's The Revolutionary Kant’), Kenneth Westphal also takes issue with some of the features of Bird's ‘revolutionary’ interpretation of Kant. As with Banham, many of Westphal's concerns are in connection with the Analogies of Experience. In this case, however, the concern is not with the general orientation of Bird's interpretation, but with the implications his interpretation has with respect to our understanding of the relation between the three Analogies of Experience on the one hand, and their subsequent relation to the later Metaphysical Foundations of Natural Science on the other. Along these lines, Westphal applauds Bird's ‘revolutionary’ interpretation in general, arguing (in agreement with Bird) that Kant's aim in the first Critique is to provide a non-Cartesian ‘descriptive metaphysics of experience’.

Nevertheless, Westphal contends that in some cases Bird does not pursue the ‘key issues far enough’, and he appeals in particular to Bird's treatment of the Analogies. Although he agrees with Bird that there are very important links between Kant's three Analogies of Experience, Westphal suggests, along, perhaps, with Banham, that the relations among the Analogies are even more close and significant than has been recognized. Following Guyer, he argues that the conjoint use of each of the three Analogies is required for us to be able to identify spatio-temporal particulars, and he thus takes issue with Bird's contention that the arguments in the Analogies are restricted to establishing merely the necessity of those a priori (transcendental) concepts and principles that are necessary for general experience.

More specifically, Westphal argues (contra Bird) that the ‘empirical criteria for using the principles of the Analogies’ are already contained in the arguments of the Analogies. According to Westphal, then, Bird's account floats at a far too general level, for he (Bird) does not claim that the Analogies by themselves provide empirical criteria for using the Analogies. Westphal disagrees. This fundamental charge provides the basis for Westphal's claim that Bird has failed to understand properly the relation between the first Critique and the Metaphysical Foundations of Natural Science. On Westphal's reading, Bird relies too heavily on a view according to which the Analogies in the first Critique are interpreted backwards from a reading of the Metaphysical Foundations.

Bird, on the other hand, takes the discussion of ‘empirical criteria’ to be supplemental to (though not inconsistent with) the pure a priori account of the categories and their principles announced in the Analytic of the first Critique. And in this, he asseverates that the general ‘transcendental’ conditions of experience presented in the Analogies differ from the ‘impure a priori’ (but not transcendental) conditions of experience which ‘belong to Newtonian physics’.

Thus, although Bird takes the Metaphysical Foundations of Natural Science to consistently implement the general principles of the Critique, he does not take the fundamental principles of Newtonian science to be ‘transcendental conditions of the possibility of experience generally’. He thus challenges Westphal's suggestion that he has conflated the role of the Critique (especially the Analogies) with that of the later Metaphysical Foundations.

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The exchange between Bird and his critics focuses on several specific issues which are central in Kantian scholarship and more broadly in epistemology and metaphysics. In addition, the debates which follow open up new avenues for further discussions in these areas. These are sufficient illustrations of the significance and richness of Bird's TRK.