The Appendix to the Transcendental Dialectic in the Critique of Pure Reason has rarely been discussed by commentators writing about the first Critique. Its placement between the Doctrine of Elements and the Doctrine of Method and its ostensible status as a mere ‘appendix’ are partly responsible for this. A more substantial reason is that it poses several exegetical problems, leading Kemp Smith (Reference Kemp Smith1984: 547) to conclude famously that ‘[t]he teaching of this section is extremely self-contradictory’. While interest in the Appendix has steadily increased over the last forty years, its structure and its place in the first Critique have not been examined in much detail. Meer's timely book fills this lacuna and helpfully discusses most exegetical difficulties concerning the Appendix. That said, Meer primarily sets out to investigate how the regulative a priori use of reason is possible given the methodological strictures of the first Critique. To avoid misunderstanding, it must be emphasized that Meer's aim is not (as the title of the book might suggest) to support the thesis that Kant can or does allow purely regulative transcendental principles; rather, Meer seeks to explain how the system of the first Critique is supposed to accommodate such principles. The book will thus disappoint those looking for a contribution to the debate on the transcendental status of the regulative principle of reason between, for example, Horstmann (Reference Horstmann1997) and Allison (Reference Allison2004) or Wartenberg (Reference Wartenberg1979). Nonetheless, it provides a valuable guide for those trying to understand this long, obscure and difficult section.

The book is divided into three parts: the first and the third parts comprise one chapter each and the middle part is composed of three chapters. The first part argues that the question how there can be regulative but transcendental principles of reason arises from within the text of the first Critique. More precisely, Kant first introduces the question of the regulative use of reason in sections 8 and 9 of the Antinomies chapter. Kant's argument in the Antinomy, according to Meer, is that only transcendental idealism can escape the dichotomy of dogmatism and scepticism (p. 52). As Meer reads it, Kant's analysis of the mistake on which the Antinomy rest is that the principle of reason is understood constitutively, i.e. as guaranteeing that any series of conditions terminates with something unconditioned. So whereas the constitutive use of reason leads to the Antinomy, the regulative use does not. This, Meer argues, raises the question he wishes to examine: how are the regulative but transcendental principles of pure reason to be reconciled with the motivation for transcendental idealism derived from the Antinomy chapter?

The second part provides three ‘analyses’ (p. 67) of the text, which collectively seek to answer that question. Chapter 3 examines the architectonic place of the ideas and principles of pure reason in the system of the first Critique. These are not simply imported from traditional metaphysics, the argument goes, but are given a metaphysical deduction in the first book of the Transcendental Dialectic. Meer transposes this term to the Dialectic in order to highlight that the three ideas of pure reason – soul, world, God – supposedly correspond to three types of syllogistic inference, which Kant labels categorical, hypothetical, and disjunctive. Meer does not attempt to illuminate this correspondence, but he does show that Kant has a systematic reason for discussing precisely these three ideas throughout the Transcendental Dialectic. Notably, however, this does not explain why the Appendix is also concerned with a triad of principles: homogeneity, specificity and continuity. According to Meer, these are derived from the logical relations between species and genera: every concept falls under some more general concept and every concept subsumes some further concepts. Meer, ingeniously, connects this to the considerations of the first book of the Dialectic. Inferences to ever more general concepts are akin to inferences from the conditioned to its conditions; the former aim at finding a most general concept, the latter at finding an unconditioned condition (p. 95).

Chapter 4 considers how the ideas and principles of pure reason are related to Kant's concepts of a system and of purposiveness. This question arises naturally, since, according to Kant, the regulative use of reason aims at the systematicity of the cognitions of the understanding and a purposive system is the most systematic. Meer helpfully outlines the parallels between the hypothetical use of reason discussed in the first part of the Appendix and its as-if use discussed in the second part. He also offers an instructive reconstruction of the relation between the concepts of systematicity and purposiveness.

Strangely, however, the discussion of this chapter does not seem to contribute to the book's broader aim. So, it is not at all obvious how Meer's reconstruction helps to explain how there is room for a transcendental principle of pure reason in the first Critique. Clearly, Kant considers the systematic unity of cognitions, which are provided by the understanding, to be the legitimate, non-illusory and original contribution of reason. But to illuminate how reason makes such a contribution, one must consider the results of the Transcendental Analytic from the perspective of the Appendix. Kant indeed refers to the results of the Analytic both in the first and in the last paragraph of the Appendix (A642/B670, A703/B731). Unfortunately, Meer considers the chief difficulty for an interpretation of the Appendix to arise from within the Transcendental Dialectic. As a consequence, his efforts to ‘contextualise’ (pp. 12, 278) the Appendix focus on its links with the Dialectic. It is certainly true that the question as to how Kant can allow for a transcendental principle of reason arises primarily in relation to the Dialectic. However, as for instance Horstmann (Reference Horstmann1997: 168–9) points out, the Analytic already raises the question of how there can be a purely regulative transcendental principle. It would thus be worthwhile to examine how Kant's positive doctrines in the Appendix complement the results of the Transcendental Analytic. Given that the concept of purposiveness further links the Appendix to the Introduction to the Critique of the Power of Judgement, it is that much more regrettable that Meer does not take up the opportunity to consider their relation.

Chapter 5 examines the transcendental deduction of the ideas of pure reason. Meer notes that Kant allows a ‘subjective deduction’ of the ideas ‘from the nature of our reason’ (cf. A336/B393). According to Meer, Kant in fact presents two justifications in the Appendix, though neither of them succeeds. The first appeals to the principle that reason cannot operate counter to its nature, which implies that there must therefore be a legitimate use of the ideas. As Meer notes, this fails to justify the particular regulative use of reason that Kant aims to defend. The second deduction makes use of the concept of an object in the idea. As Meer reads him, Kant offers the same kind of deduction as in the Analytic, but restricts the argument to objects in the idea. But this, Meer argues, is incompatible with Kant's criticism of traditional metaphysics in the Dialectic, which points out that the ideas of reason are not objects. Here, however, Meer's reconstruction of the arguments is unsatisfactory as it largely consists of paraphrases or direct quotations of Kant's claims and little effort is undertaken to make these comprehensible to the reader. Nor does Meer attempt to capture the spirit of Kant's arguments. From a dialectical point of view, the argument Meer bills as a first justification appears not so much justificatory in intent as motivational: it seems to argue for the importance of a transcendental deduction of the ideas, not to provide one. Meer's objection to the second argument he discusses neglects Kant's repeated insistence that ‘objects in the idea’ are merely schemata (e.g. A670/B698, A674/B702, A682/B710).

The third part of the book, consisting of the final chapter, discusses the ‘concrete functions of the regulative principle of reason’ (p. 215). Meer places the examples from chemistry, anthropology and astronomy that Kant presents in the first part of the Appendix in their historical context, traces Kant's engagement with these sciences through several of Kant's works and provides explanatory illustrations. This part is thus a helpful guide to the scientific examples discussed in the Appendix.

The chief strength of Meer's book is indeed that it provides an instructive and scholarly survey of the many themes that are interwoven in the Appendix and diligently traces them to other passages, albeit mainly in the Transcendental Dialectic. It is regrettable that the book does not aim to contribute to the debates surrounding the Appendix, although Meer's careful textual analyses would enable him to do so. There are also, as I have said, various missed opportunities to discuss passages outside the Transcendental Dialectic. As it stands, the book neither defends a particular interpretation of the Appendix, nor is it a comprehensive commentary. It is therefore difficult to recommend it in its entirety to anyone but specialists, though chapters 3 and 6 may appeal to a wider audience, and the latter chapter in particular will be a useful resource for anyone reading or teaching the Appendix for the first time.