Kant's <i>Critique of Pure Reason</i> and the Method of Metaphysics By GabrieleGava.Cambridge: Cambridge University Press, 2023. xii + 286 pp. <scp>ISBN</scp>: 9781009172127

Gava's book substantially contributes to the study of Kant's meta-metaphysics by advancing two main theses. The primary thesis states that “the critique of pure reason,” as the project carried out in the Critique of Pure Reason,1 is “the doctrine of method of the whole of metaphysics” (208; see also 2, 4, 8, 11, 15, 41, 63, 65, 223, 267). Crucially, the main task of a doctrine of method is not to clarify argumentative procedures, but “to show that a body of cognition has ‘architectonic unity’,” which is required to establish that “a science is indeed a science” (11).2 The critique therefore establishes “that metaphysics can attain the status of a science because it is capable of achieving ‘architectonic unity’” (267). To achieve this unity, metaphysics must be oriented towards its “fundamental ‘idea’” (7), which Gava identifies as the “‘worldly concept’ (Weltbegriff) of philosophy” (17–8). Gava supports his primary thesis by citing two chief passages, which are “often completely overlooked” (41). In the B-Preface, Kant characterises the critique of pure reason as “a treatise on the method, not a system of the science itself” (Bxxii).3 And likewise, in the Guiding Thread chapter, Kant seems to identify the critique with a “doctrine of method” (A83/B108). Over the course of his book, Gava seeks to show that “these claims should be taken literally” (15). The critique of pure reason literally is a doctrine of method, specifically the doctrine of method of metaphysics—nothing more, nothing less. The Critique of Pure Reason does not, however, provide a “system” of transcendental philosophy, but is “a treatise on method.” This does not mean a doctrine of the technique of procedure, but rather a complete determination of the “whole outline” and the “whole inner articulation” of ontology. In this groundwork of metaphysics as a plan for the inner possibility of ontology, the “whole sketch of a system of metaphysics is mapped out.” (1951/2010: 16). This shift, however, also invites the main objection to Gava's primary thesis. Why, if the critique of pure reason is a doctrine of method, should the book, Critique of Pure Reason, also contain a doctrine of elements? And indeed, why should the Doctrine of Elements make up the main bulk of the Critique, taking up 701 of the B-Edition's 884 pages? Gava acknowledges this objection, framing it as a puzzle: “an additional challenge comes from the fact that Kant characterizes both the whole Critique and one part of it as a ‘doctrine of method’, which is confusing.” (2). To solve this puzzle and defend his primary thesis, Gava advances the secondary thesis of his book: transcendental philosophy, as established in the Doctrine of Elements, is merely instrumental in achieving the goal of the critique of pure reason, i.e., showing that metaphysics has architectonic unity. In Gava's own words: “the Critique contains elements of transcendental philosophy because they are instrumental to its role as the doctrine of method of metaphysics” (5; see also 2, 4, 15, 41, 54, 63, 74, 175–7, 191–2, 267–8); and accordingly, “the Transcendental Doctrine of Elements has the sole purpose of enabling the Transcendental Doctrine of Method to do its job” (59; my emphasis4). The secondary thesis draws on a specific understanding of transcendental philosophy and its relation to the doctrine of method. Gava contends that “the chief purpose of transcendental philosophy is to investigate ‘root’ concepts and to show that they are valid, which implies that synthetic a priori judgements based on them are also valid.” (258) In so doing, transcendental philosophy provides some of the material to be brought into architectonic unity. This is crucial because, as Gava notes, “a doctrine of method rests on the previous establishment of at least some parts of the science of which it is a doctrine of method,” and thus “the Critique of Pure Reason requires that at least some parts of metaphysics be established in its ‘Doctrine of Elements’” (2).5 Let's restate Gava's two main theses as follows: ‘Nothing-Other’ Thesis (NOT) Kant's project of a critique of pure reason is nothing other than a doctrine of method of metaphysics: the critique's entire goal is to show that metaphysics can achieve architectonic unity. ‘Mere-Instrumentality’ Thesis (MIT) Kant's transcendental philosophy is merely instrumental towards the goal of a critique of pure reason: to show that metaphysics can achieve architectonic unity, we must establish some of its materials. Taken together, NOT and MIT offer a new and exciting reading of the Critique, to which I will refer as ‘Gava's reading’. Gava's reading—if true—would quite drastically alter our understanding of the critique's ultimate purpose and structure. The book thus deserves, and will no doubt attract, careful scholarly engagement, of which this review is only a small part. My review focuses on Gava's main theses, which do not exhaust the book's contribution. In working out the textual details, Gava most notably reconstructs “a metaphysical and a transcendental deduction of space and time in the Aesthetic, […] of the categories in the Analytic, and […] of the ideas of reason in the Dialectic.” (6) These reconstructions, which constitute Part II of the book, are both nuanced and ambitious. I wish to probe Gava's reading by contrasting it with, what I call, the ‘Neo-Kantian reading’ of the Critique.6 The Neo-Kantian reading agrees with Gava that the critique of pure reason must show that metaphysics has architectonic unity to achieve the status of a science. But while Gava appears to think that architectonic unity is both necessary and sufficient for being a science, the Neo-Kantian reading introduces a second necessary condition: metaphysics can only be a science if its cognitions count as knowledge. Given this extra condition, we should deny NOT because the critique also aims to demonstrate that metaphysical knowledge is possible; moreover, insofar as this is done by establishing transcendental philosophy in the Doctrine of Elements, we should also deny MIT. The Neo-Kantian reading, I venture, is well supported by the text, and retains the textual insights of Gava's reading, while overcoming some of its limitations. But let's take things step-by-step. In Part I of his book, Gava argues that the critique aims to show that metaphysics has architectonic unity because: first, “[w]hen Kant describes the project of the Critique of Pure Reason, he often stresses that its main aim is to establish whether and how metaphysics is possible as a science” (16); and second, “Kant submits that having ‘architectonic unity’ is a condition for becoming a science, which means that the Critique must show that metaphysics is capable of this unity.” (15). I agree with both these premises. First, I agree with Gava that the main aim of the critique of pure reason is to show how metaphysics is possible as a science. Kant explicitly says so in numerous passages. Both in the B-Preface and in the Prolegomena—which is, after all, the prolegomena to any future metaphysics that will be able to come forward as a science—Kant asks: “How is metaphysics possible as a science?” (B22, 4:280) In the Prolegomena, he adds that answering this question is “the essential content of the critique” (4:280),7 which is why, as he clarifies in the B-Preface, “the critique of reason ultimately leads to science” (B22). We find similar claims in many other passages.8 Second, I agree with Gava that “one condition for attaining the status of a science is possessing ‘architectonic unity’.” (16). In the Architectonic of Pure Reason, Kant notes that “systematic unity,” or specifically architectonic unity, “is what transforms common cognition into science” (A832/B860). Similarly, in the Jäsche Logic: “Science is a whole of cognition as a system and not merely as an aggregate.” (9:139) Or more succinctly in the Vienna Logic: “A science is a system.” (24:813) Kant also specifies that the system of a science “rests on an idea of the whole, which precedes the parts” (9:72). And this is just the tip of the textual iceberg.9 But although I agree with Gava that architectonic unity is one condition of a science, I argue that it is not the only condition for Kant. Specifically, Kant insists that the cognitions we systematise must qualify as knowledge. This is not only supported by the close etymological link between the German terms for science (Wissenschaft) and knowledge (Wissen), but also by abundant text: “From knowledge derives science” (9:72); “Science is nothing other than the cognition by which we know something.” (24:440); and conversely, if “we don't know the rules” of a discipline, “then it cannot be a science” (24:791). And again, we find many more such passages.10 There are hence two necessary conditions for a science (which are, presumably, jointly sufficient). Put precisely: Kant's Account of Science We thus have strong textual grounds for the Neo-Kantian reading, which moreover anticipates the Critique's two-part structure. To establish metaphysics as a science, the critique must show: (i) that metaphysical cognitions can achieve architectonic unity; and (ii) that metaphysical cognitions qualify as knowledge. I concur with Gava that the former is done in the Doctrine of Method, yet I add that the latter is achieved in the Doctrine of Elements; after all, it is in the Doctrine of Elements that Kant demonstrates the possibility of metaphysical knowledge by advancing his transcendental philosophy. The Neo-Kantian reading thus denies NOT: the critique is not just a doctrine of method, but also a doctrine of elements; and accordingly, it also denies MIT: transcendental philosophy is not merely instrumental to the project of the critique, but a constitutive part. A brief terminological clarification: while there is a salient sense in which constitutive parts are also instrumental, this is not the intended sense. Of course, transcendental philosophy is instrumental to the critique in that it shows how metaphysical cognitions can be knowledge which satisfies the second condition of metaphysics being a science. However, in this same sense, showing that metaphysics has architectonic unity is also instrumental to the critique because it satisfies the first condition. So, when Gava advances MIT, he must mean to say that transcendental philosophy is merely instrumental in that it is instrumental and not constitutive. That is the sense of ‘instrumental’ intended throughout this review, and it is the sense in which the Neo-Kantian reading denies that transcendental philosophy is merely instrumental to the critique. The Neo-Kantian reading, thus established, claims further benefits. For one, it can deny NOT while accommodating Gava's two chief passages, thereby preserving the textual insight of Gava's reading. We can take Kant literally when he calls the critique “a treatise on the method” in the B-Preface (Bxxii) and a “doctrine of method” in the Guiding Thread chapter (A83/B109). For neither passage must be read as giving an exhaustive account of the critique. The critique may literally be a doctrine of method while also being a doctrine of elements—as the Neo-Kantian reading suggests. Importantly, then, neither passage forces Gava's formulation of NOT, on which “Kant equates the whole Critique to a doctrine of method” (60; my emphasis). The Neo-Kantian reading also benefits from rejecting MIT. Most notably, it can acknowledge that the bulk of the Critique actually belongs to the critique: transcendental philosophy, as developed in the doctrine of elements, is not just a mere means to the critique's end, but constitutively belongs to it. Accordingly, the Neo-Kantian reading can also take literally Kant's claim that transcendental philosophy is a constitutive part of the critique of pure reason: “Everything that constitutes transcendental philosophy […] belongs to the critique of pure reason.” (A14/B28) By contrast, Gava would have to either tweak passages like this one or sweep them under the proverbial rug, since he holds that transcendental philosophy is merely instrumental to the critique.14 Given his commitment to MIT, Gava also struggles to explain why the critique must answer the question: “How are synthetic propositions a priori possible?” (B73; 4:276). Kant clarifies that doing so is not just the “general task of transcendental philosophy” (B73), but also “the proper task […] to which my critique […] was entirely directed” (4:377; my emphasis). Answering the question thus constitutively belongs to the critique. Gava addresses this task in his reply to Land's (2024) review.15 There, Gava acknowledges that, on his reading, explaining the possibility of synthetic propositions a priori “is not what characterizes the critique of pure reason” (2024: 139); this explanation belongs to transcendental philosophy, and so serves the critique merely instrumentally. If [metaphysics] is to claim to be a science based not merely on deceptive persuasion but on insight and conviction [Überzeugung18], a critique of reason must […] demonstrate the possibility of synthetic a priori cognition […]. Thus critique, and it alone, contains the entire well-tested and proven plan, indeed all the means of execution, by which metaphysics can be brought about as a science. (4:365). In closing, I would like to draw out an implication of the Neo-Kantian reading for Gava's discussion of belief (Glaube). In the Architectonic, Kant curiously includes transcendental cosmology and transcendental theology—as parts of “transcendent physiology”—inside the system of metaphysics (A846/B874). This is puzzling.19 If metaphysics is to count as a science proper, rather than a pseudo-science, it should not include “pseudo [scheinbare] […] philosophical cognition” (A841/B869). Gava addresses this puzzle by arguing (i) that the claims of transcendent physiology, while falling short of knowledge, are justified as articles of belief (7–8, 153, 161); and (ii) that “the critique uses [these articles] to establish that metaphysics can become a science” (228; see also 208). While I don't claim to have a better solution to this general puzzle, Gava's solution doesn't work either—(i) is true, but (ii) is false. As the Neo-Kantian reading has highlighted, the critique aims to demonstrate that metaphysics is possible as a science—a point Gava acknowledges. But given Kant's own account of science, this requires that all cognitions within metaphysics count as knowledge. Kant insists: “Metaphysics must be science, not only as a whole, but also in all its parts, otherwise it is nothing at all” (4:371).20 Belief, by contrast, cannot secure the status of a science, as Kant makes clear in the Prolegomena: if metaphysics were to “speak the humble language of rational belief,” it would “not conduct its business as a science” (4:278; see also 4:371; 24:852).21 But even if science only needed belief, Gava seems to be of two minds about the required species of belief. At first, he argues that Kant instrumentally justifies the soul, world, and God relative to the ends of theoretical reason as “what Kant calls ‘doctrinal belief’” (159; see also 161–3). But later, Gava suggests that the ideas are included in the system of metaphysics relative to the ends of practical reason as “moral beliefs” (221; see also 215–26). While Kant accepts, of course, that we have both doctrinal and moral belief in, say, God's existence (A826–8/B854–6), Gava doesn't explain how the two relate in the system of metaphysics. Moral belief in God doesn't, pace Gava (225–6), explain why the system includes transcendental theology, which Kant contrasts with moral theology (28:1012; 28:1071). Doctrinal belief in God may avoid this problem.22 This concludes my review. Gava's book presents an ambitious and illuminating interpretation of the critique of pure reason as a doctrine of method for metaphysics. While I remain unconvinced that this interpretation fully captures the critique's nature—which must, by its constitution, also demonstrate the possibility of metaphysical knowledge—I'm in no doubt that the book makes a significant contribution to current debates on Kant's meta-metaphysics. I recommend it to anyone working on Kant's account of critique and its relation to transcendental philosophy. The book is clearly written, carefully argued, textually attentive, and rich in insight, both in detail and in scope.23