In this book, Catherine Wilson provides both a ‘survey’ and a critical appraisal of Kant’s philosophy from the wide historical perspective of eighteenth-century philosophy. The characteristic strategy of the book is to avoid ‘some of the complexities of structure and terminology that impede a deep and intuitive understanding of his thought’ (p. 2) and to emphasise the connection and the opposition of Kant’s views to his contemporaries concerning a variety of topics ranging from the origins of the world to the principles of morals and politics. Thus, about half of the space of each chapter is devoted to expositions of the views of these precedents (which are very instructive for the non-specialist). Against this background, according to Wilson, two features of Kant’s philosophy stand out:

With respect to the historical context, Wilson’s characteristic claim is that the major objective of Kant’s philosophy was the critique of the rising naturalism and materialism:

In her Introduction, Wilson tells how the picture of Kant as engaging with pure metaphysical and epistemological issues puzzled her as a student and turned out to be abstract. As a historian, moreover, she wants to question the celebrated picture of Kant as a leading philosopher of the Enlightenment. According to Wilson, in fact, Kant was mainly worried by the moral and religious implications of naturalism and materialism and hence he was at odds with a major trend of the Enlightenment. In this perspective, Wilson brackets Kant’s lifelong confrontation with German academic philosophy and with the writings of Newton, Euler, Haller, Boerhaave, and other scientists, and she focuses on materialist and radical political thinkers following the ‘interpretive hypothesis that Kant’s critical philosophy is a response to these other critical philosophies – those of the radical enlightenment – whose representatives opposed academic philosophy more consistently and decisively than Kant did’ (p. 264). Wilson takes for granted that the ideas of the radical enlightenment are closer to ours and points out that Kant had unpleasant opinions, for example, concerning race, sex, and social inequalities, in contrast with ‘a hagiography that characterizes much Kant scholarship’ (p. 21). This approach produces both interesting and problematic results. As I will argue, the most problematic conclusions concern Kant’s transcendental philosophy and theory of natural science, while the most effective results of Wilson’s reconstruction concern Kant’s morals, doctrine of rights, and philosophy of history.

In Chapter 1 (Discoveries and Controversies), Wilson introduces her argument concerning Kant’s programme focusing on the declared intention, in the Critique of Pure Reason, to ‘cut off, at the very root, materialism, fatalism, atheism, freethinking lack of faith, fanaticism, and superstition’ (Bxxxiv) and the remarks in the Transcendental Dialectic on the ‘interest of reason’ of limiting the denial of the ‘foundation stones of morality and religion’ such as freedom of the will and the idea of God. In this perspective, Kant’s phenomenalism is conceived as motivated by his anti-materialism. However, this focus on materialism strikes me as unilateral. Kant’s first motivation in critical philosophy – as Wilson occasionally grants – was the critique of all kinds of metaphysical dogmatic theories, from spiritualism to materialism. In the Transcendental Aesthetic and Analytic, as is well known, Kant singles out different doctrines: he rejects the views of Newtonian and Leibnizian philosophers, and he focuses on the role of mathematics in the foundation of scientific knowledge; in the Antinomy, the anti-metaphysical doctrine that he directly examines is empiricism rather than materialism.

The weakness of Wilson’s hypothesis in this regard is evident in Chapter 2. Wilson correctly shows that Kant’s investigation of these topics, crossing all his philosophical writings, originates in an engagement with Newtonian science and Leibnizian monadology. However, Wilson maintains that ‘by arguing that the Newtonian science of matter and motion, though exact, was not a representation of ultimate reality, and that materialism was a speculative, rather than a hard-headed empirical doctrine, Kant intended to deprive the naturalistic image of the human being, as it was being shaped by his opponents, of its substance’ (p. 2). Concerning the system of critical philosophy, in particular, ‘to describe this vindication of empirical methods as offering needed foundations for Newtonian science is to miss the point: the aim was to provide foundations for a physics purified of unwanted implications’ (p. 20). The dangers of materialism were certainly an important element in Kant’s intellectual development, for the very category of materialism had become a central target of German academic philosophy, as physical monadology turned out to be a possible support for materialism and the activity of La Mettrie and Maupertuis in Berlin raised concerns and debates. However, Kant’s genuine interest in the possibility of metaphysics and the foundations of natural science dominates both his pre-Critical and Critical writings, and there is no evidence that materialism and naturalism were the main aims of these investigations; they were rather important implications of the latter.

In this regard, Wilson’s use of a broad selection of Kantian texts ranging from early to late writings and including Nachschriften of lectures and the Opus postumum correctly suggests that Kant’s thought cannot be reduced to the picture of the closed critical system, but occasionally obscures the main points of Kant’s works, because many manuscript reflections and indirect testimonies cannot be taken at face value where they significantly depart from Kant’s published works. One example of this problem is in Chapter 3 concerning the theory of matter – as Wilson asks ‘why would Kant remain firmly wedded to the inertness of matter, the exclusive intelligibility of mechanical explanations, and the incomprehensibility of life when his immediate predecessors and his contemporaries were exploring creative and varied forms of “vital materialism”? Only in the Opus postumum did these theories really engage his attention’ (p. 85). Wilson’s answer is ‘that Kant sought acceptable reasons to believe that natural science could never fully understand life and thought in order to create room for faith in supersensible teleological principles. By refusing to align himself with any of the existing theories of life and matter, whether spiritual, vital, or materialistic, and by insisting that the human understanding was exclusively adapted to explanation in terms of mechanical causality, Kant turned the gaps in eighteenth-century empirical science into a moral and political opportunity’ (ibid.). Kant indeed dealt with vital materialism in many (published and unpublished) writings, starting from the peculiar superposition of monadology and materialism that his own early cosmology could allow, and tried to make sense of the notion of life-force until the Opus postumum with no conclusive result. However, one wonders why he should ‘align’ with available theories. In fact, the problem continued to be debated across the whole nineteenth century, and Kant’s approach inspired the physicalist epistemology of prominent scientists such as Alexander von Humboldt and Hermann von Helmholtz, who were arguably not motivated by the ‘moral and political opportunity’ of turning scientific problems into anti-materialist arguments.

One last example of these interpretative limits and problematic use of the corpus is Chapter 5, where Wilson examines Kant’s views on the physiology of mind. After a long survey of the precedents, Wilson examines Kant’s views without mentioning the essay on Sömmering’s ‘On the organ of the soul’, which is Kant’s most detailed account of the matter in the late works and includes a positive appraisal of the physiology of mind. Wilson draws from passages on the soul in the metaphysical Nachschriften, although she grants that Kant did not care about the afterlife.

The contrast between Kant’s transcendental philosophy and the moral and political issues of Kant’s time is much more effective in the following chapters. The gap between Kant’s moral imperative and the pure doctrine of rights, on the one hand, and Kant’s views about how these principles apply to the natural and historical world is correctly emphasised and casts light on Kant’s intellectual profile. In Chapter 6, for example, Wilson argues that Kant’s insistence on retributive justice was politically backward with respect to the views of advocates of the Enlightenment, such as Cesare Beccaria. Wilson is also right to point out the gap between Kant’s moral universalism and his acceptance of common prejudices about the inferiority of non-European people and women, conceived as results of natural dispositions. In the transition from pure rational principles to phenomenal reality, Kant takes many current views concerning race, society, and sex as natural features of the world, thus distancing himself from the more reformative and revolutionary trends of the Enlightenment (this example suggests, by the way, that the resort to nature in the eighteenth century could be controversial).

In Chapter 7, Wilson also notices a fundamental gap in Kant’s moral philosophy, disputing Kant’s claim that ‘everyone grasps an objective distinction between hypothetical imperatives of prudence and the categorical imperatives of morality and that everyone feels the force of this law’ (p. 173). This points to a problematic side of Kant’s universalism. However, Wilson is less convincing in insisting on Kant’s alleged belief that faith in God is a necessary motivation for moral actions, failing to correctly recognise Kant’s sharp separation of pure moral motivation and postulates in the Critique of Practical Reason, as well as Kant’s theory of ‘moral theology’ and ‘moral faith’, which was based precisely on the idea of reversing the traditional direction of implication from faith to morality.

Wilson’s discussion of teleology and biology in Chapter 8 deals once more with this connection between pure philosophy and empirical reality, with mixed results. Wilson dismisses as ‘an impossible position’ (p. 192) Kant’s effort to construct a ‘grand system of nature’ based, at the same time, on the fundamental ignorance of the ultimate grounds of reality and the reality of the will and the formative drive. This is a disputable conclusion. A Kantian approach of combining metaphysical ignorance, mechanism, and teleology turned out to be seminal for generations of scientists in the nineteenth century, and it is certainly too far-fetched to conclude that ‘the repetitious phraseology and disorganization of the Critique of Judgment of 1790, and the wild speculation of the Opus postumum not only reflected the inadequacy of metaphysics to deal with some of the most complex problems of biology but foreshadowed the oncoming health crises’ (p. 197).

Wilson’s examination of Kant’s account of the problem of evil and warfare also points out that the gap between supersensible ideas and nature allowed the introduction of Kant’s occasionally biased opinions, such as the ‘pessimistic image of humanity’ and ‘continual antagonism’ as a condition of the development of human capacities. The compatibility of mechanism, individual ends, and the course of history is presented as a kind of secular theodicy. Wilson points out that ‘in “Perpetual Peace” he seems to abandon his view of war as an instrument of progress—at least where inter-European warfare is concerned’ (p. 256). However, Wilson downplays this turn and its possible connection to Kant’s late views on the French Revolution as the opportunity for a display of universal ‘moral dispositions’ in the Conflict of the Faculties. By presenting antagonism as the guiding thread of Kant’s philosophy of history, Wilson connects the latter to Hegel and to ‘nineteenth-century political philosophy with its faith in higher purposes, superior and inferior types, necessary sacrifices and suspensions of the moral’ (p. 258). However, this is just one side of Kant’s legacy in this field (which is more properly bound to Hegelian notions of the ethical State transcending individual morality). Kant’s legacy in philosophy of history and political theory also included, for example, Friedrich Lange’s ideas of social reform, Hermann Cohen’s secular messianism, Ernst Cassirer’s cosmopolitical critique of culture, and Carlo Cattaneo’s project of the ‘United States of Europe’ as a realisation of Kant’s ‘federation of states’.

On the whole, Wilson’s book is instructive and provides important historical and critical insights, but its general claim is not justified. ‘The Kant who emerges from my study’ – as Wilson clearly spells out – ‘is a powerfully revisionary philosopher, launching a revolution conservatrice against the materialism, atheism, and hedonism that underwrote the moral and political ideals of the radical Enlightenment’ (p. 21). To be sure, as Wilson also admits – using once more Jonathan Israel’s categories – Kant is usually considered as a representative of the ‘moderate’ Enlightenment, that is the non-materialist, non-democratic trend of Enlightenment exemplified among others by Voltaire. Wilson coherently rejects this ranking, arguing that ‘What is Enlightenment?’ focuses ‘almost exclusively (8:41) on the right of scholars to publish uncensored, unorthodox materials on religion and on taxation’ (p. 202). In fact, Kant’s focus on the autonomy of reason ranged far beyond these particular issues, from the notions of rational religion and morals to the (conditional) approval of political Revolutions, and these are the reasons why Kant was understood as a philosopher of the Enlightenment by both followers and conservative critics. It is thus historically inappropriate to talk, as Wilson does, of ‘Kant’s revisionary programme’, and plainly wrong to talk of his ‘revolution conservatrice’. Kant was participating in the ongoing controversy in the field of Enlightenment, and it is historically unfit to ask rhetorically, as Wilson does, ‘why not take the view that although materialism and mortalism were true, and moral effort could not be philosophically justified, one might nevertheless live virtuously as Spinoza had, or at least live controlled by public opinion and the law, as Hume implied was sufficient for pleasant social functioning?’ (p. 263), as if Kant’s failure to subscribe to all the ideas of radical Enlightenment and naturalism made him a conservative thinker.

Wilson’s objective, in fact, goes beyond historical analysis. She wants to question the very importance of Kant in the light of contemporary views, in contrast to past ‘hagiography’, except for some general insights such as ‘the deeply rooted will to harm and exploit others for one’s own benefit; the feeling for morality that is the counterweight to it; and the transmissibility of acquired knowledge and practice from generation to generation’ (p. 267). On the negative side, Wilson concludes her analysis with one more rhetorical question:

Kantian scholarship, with its persisting interest in Kant’s intricate accounts of the knowledge of nature and its limits, appears to have dropped that veneration long ago and to be currently engaged in the same reappraisal of the role of naturalism and materialism in Kant’s philosophical development that is the pursuit of Wilson’s book.