For Alfredo Ferrarin, reason is that ‘something in us which transcends nature’, which stands in opposition, but also in relation, to the givenness of our contingent, material condition (p. 284). More than a mere mechanism, responding to the brute facticity of our state as finite, sensible beings, reason is an active power that shapes, orders, constructs and even reforms the world we inhabit. ‘Reason is the institution of order and laws in its scopes of application for the sake of ends it sets itself’ (p. 283).

Throughout this rich, erudite and provocative work, Ferrarin seeks to illuminate ‘the powers of reason and the compatibility between our finitude and reason’s essence as a priori synthesis and activity’ (p. 283). Concomitantly, Ferrarin undertakes a thorough re-examination of Kant’s conception of reason’s structure, its internal articulation and its drive to unify both its experience of the world and its own activity. The questions of reason’s most fundamental powers and its ultimate unity are two aspects of the question of reason’s essence, and they prove to be interwoven, for reason is nothing but a synthesizing power active in multiple domains, the ultimate manifestation of which is reason’s reflexive concern with its own unity.

In three long chapters, each of which could stand alone as a short monograph, Ferrarin explores Kant’s ‘idea of a system of pure reason’ and ‘the philosophical problems that threaten its unity’ (pp. 9, 2). Though at first these three chapters appear somewhat disconnected, as one works through the book it becomes clear that each is an exercise in trying to ‘read Kant’s philosophy as a developing whole’ (p. 8). Accordingly, each provides a distinct window on the problem of reason’s unity. Ferrarin presents Kant as a zetetic philosopher continually probing this problem, searching for new insight into reason’s problematic unity, exemplifying the restlessness of reason that seeks to know itself through knowing its limits, which are not merely negative restrictions but also what gives reason a distinct eidetic structure.

Chapter 1, ‘The Architectontic and the Cosmic Concept of Philosophy’, provides a novel reading of the principal aims of the Critique of Pure Reason and Kant’s place in the history of modern philosophy. Rejecting the standard thesis that Kant is primarily concerned with refuting scepticism and providing a foundationalist epistemology, Ferrarin argues that Kant’s most fundamental innovation consists in expounding an account of reason as teleological, wherein all cognitive activity is conditioned by reason’s striving for totality.

This conceptual reorientation is explored through an analysis of the tension between two images found in the Architectonic: ‘reason is a seed from which an organism grows internally as a systematically articulated unity, and it is an architect who plans the edifice of reason’s laws’ (p. 22). Ferrarin observes how Kant, in attempting to describe the dialectic between these images, ‘employs analogies that shift from an edifice to an organism to personality … from the realms of art, living nature, and morality’ (p. 34). Reason’s systematic unity and its purposive activity seem to require aspects of each of these analogies since it is simultaneously like an independent, self-sustaining and internally organized organic being, driven by needs and interests, and a self-determining, legislative and poietic power that actively constructs its own order through its teleological projections.

The tension between organism and architect reflects the doubleness of an idea, as ‘both a totalizing drive based on reason’s need to project a whole as a unitary scope for its objects and a necessary guide for reason’s activities’ (p. 22). Ideas are the means by ‘which reason can think the completeness at which it aims in a determinate way’ (p. 28). Unlike a natural organism, which simply has determinate, given ends, reason generates its own ends to guide its activity and to bring the activity of its various faculties into some order, for ‘an idea is at once an end and a principle of organization of parts’ (p. 43). Moreover, in its projection of these ideal totalities, ‘reason becomes aware of its internal articulations and limits’ (p. 30). That is, reason obtains self-knowledge through the projection of and reflection on its ideas. Reason’s self-knowledge is concurrent with its striving for unity.

Ferrarin argues that properly attending to the significance of reason’s power to project ideas for the sake of directing and ordering its operations shows how even though ‘reason as a whole is divided into three faculties that direct themselves to different objects and function according to different rules’, ‘they are not disiecta membra, isolated faculties to be treated each as a separate substantial agent. They are the different modalities of a unitary power’ (p. 45).

Accordingly, the philosophic orientation complementing this understanding of reason must encompass the range of its activities while being pre-eminently concerned with the ultimate unity of this plurality. For Ferrarin, Kant’s cosmic concept of philosophy seeks to uncover how all of reason’s questions are connected to one another in a system and ultimately to the question of ‘our final destination and the highest good: a world in which morality and happiness can coincide. This is the idea underlying all other ideas that satisfies reason’s highest need and the idea behind a system of philosophy’ (pp. 58–9). That is, the highest good assures the coherence of reason’s multiple endeavours by providing a principle for ordering its various projects. Cosmic philosophy, guided by its Weltbegriff, i.e. ‘the idea of an absolute and unconditional totality’, coordinates all essential ends ‘in an organic unitary system’, through subordination to one final end, namely, ‘the ultimate destination of human beings’ (pp. 86, 81). Cosmic philosophy is, thus, ‘the science of the relation of all cognitions to the essential ends of human reason (teleologia rationis humanae)’, and the philosopher ‘the legislator of human reason’ (A839/B867).

Chapter 2, ‘A Priori Synthesis’, complements the examination of reason’s unity by illuminating ‘how reason’s a priori synthesis is the effect of an innerly articulated reason, that is, a reason that is inclusive of pure intuition, understanding, and reason proper’ (p. 108). Moreover, in keeping with his holistic interpretation of Kant’s oeuvre, Ferrarin argues that the problem of the possibility of synthetic a priori judgements is not confined to the first Critique, but remains ‘the problem of Kant’s critical philosophy’ (p. 108).

Ferrarin begins from the thesis that all thought entails synthesis. All thought is, in some way or another, the activity of unifying a multiplicity. This act of forming an ordered whole from a preliminarily given manifold is ‘a pure spontaneity’ and constitutes ‘pure reason’s power to go out of itself and determine something real that was not implicit or given in its starting position’ (pp. 113, 107). Ferrarin introduces what he calls a ‘form-content’ pair to describe what is created in any a priori synthesis and to distinguish the activity of reason in this mode of judging from a purely logical one, where reason, disregarding content, looks for merely formal consistency in its analysis of conceptual relations.

While Ferrarin explains how the generation of ‘the pair form-content, [which] is a rule, a law, a principle we constitute’, works in various domains (moral, mathematical, transcendental, aesthetic and metaphysical), his account of how this productive activity grounds objectivity is especially interesting (p. 106). Arguing that every empirical synthesis presupposes and corresponds to an a priori synthesis, Ferrarin shows that objectivity is ‘a universal and necessary projection’ and that ‘knowing objectivity is the a priori cognition of a frame in which individual experience’ may occur (p. 122). Thus even the ostensible passivity of sensibility’s receptivity depends on the spontaneous power of reason, on a synthetic a priori activity, which ‘produces judgments that extend our cognitions’ (p. 180).

This power of extending our cognitions, however, underlies ‘both the positive and immanent part of metaphysics, that is, the production of objectivity in the Analytic, and its negative and transcendent part, that is, the vain pretension to determine the noumenon that we need to censor in the Dialectic’ (p. 126). Thus the same power underlies both what makes experience possible and what can carry us beyond all possible experience. Reason’s a priori synthetic capacity is the source of intelligibility and of reason’s ‘peculiar fate’.

Chapter 3, ‘Kant on Kant’, provides a meta-level analysis of Kant’s reflection on his own work and raises questions about ambiguities and equivocations encountered in his writings. Painstakingly tracing subtle changes in the meanings of important notions and technical terms such as concept, intuition, idea, knowledge, faculty and objectivity, Ferrarin meticulously reconstructs various shifts and developments in Kant’s mature thought. His remarkable display of erudition, which ranges across Kant’s whole corpus, serves the philosophic purpose of trying to understand ‘why Kant proves so indecisive about the definition of knowledge, the status of transcendental philosophy, the role of metaphysics, and the propaedeutic function that the critique of pure reason has with regard to metaphysics’ (p. 23).

Though Ferrarin does not shy away from acknowledging the problems generated by such ambiguities, he never simply criticizes Kant. Rather than an indication of confusion or carelessness, changes in the meaning or application of a term are often the effect of what Ferrarin calls Kant’s ‘hunger for relentless [philosophic] progress’ (p. 3). This hunger, however, always remains guided by the idea of a unity of reason, which Ferrarin compares ‘to a palimpsest, written upon many times with remnants of earlier, imperfectly erased writing and marks still visible’ (p. 5).

Ferrarin’s careful deciphering of this palimpsest helps, in particular, to illuminate Kant’s recasting of the relations between reason’s faculties. For example, he calls attention to how, from the vantage point of the Critique of Judgement, the two previous critiques take on a new relation to one another and how ‘the power of judgment mediates between the legislations of the understanding and of reason’ (p. 275).

Ferrarin’s work overflows with challenging arguments, helpful observations and provocative questions. His magisterial presentation of reason as ‘a legislative, end-setting, self-organizing, architectonic, unifying and autonomous power’ will certainly open up new paths for Kant scholarship and new ways of understanding the revolutionary significance of Kant’s thought (p. 292). In conclusion, I would like to illustrate the fecundity of Ferrarin’s work by focusing on one tacitly suggested line of thought. Ferrarin cites, as the epigram to the first chapter, Kant’s famous statement on theodicy from the Bemerkungen in den Beobachtungen über das Gefühl des Schönen und Erhabenen:

Given the prominent location of this citation, it is notable that neither the subject of theodicy nor the notion of providence receives any explicit treatment. Why then does Ferrarin choose this passage for the first chapter’s epigram?

Ferrarin seems to be suggesting that the account of reason’s unity that lies at the heart of Kant’s critical project is a kind of theodicy. However, rather than seeking to justify God’s ways, it is reason itself that is on trial. Critical philosophy asks reason to give an account of itself and its activity. If Ferrarin intends for the reader to draw a comparison between Kant’s endeavour and his description of Newton and Rousseau, then Kant justifies reason by uncovering an order or unity, where there ostensibly was only chaotic multiplicity. This raises the question: is the mere discovery of reason’s essential unity sufficient to ‘make Pope’s theorem true’ or must reason justify itself through actively bringing order into the world? If the latter, then the misuse of reason’s powers would leave the world unjustified. This possibility makes the criticism and discipline of reason all the more significant. In other words, is Kant’s philosophic project, which intends to promote the right use of reason, i.e. to encourage us to follow ‘the critical path’, an exercise in theodicy?