Two new books on Immanuel Kant present such contrasting visions of the philosopher, his work, and his legacy that the uninitiated reader might wonder if they are really about the same person. The first, by the Frankfurt philosopher and general editor of Kant’s works, Markus Willaschek, offers a lucid and overwhelmingly positive account of a philosopher worth revisiting at a time when liberal internationalism, expertise, and even science and reason seem under threat. Ian Hunter’s challenging and sobering book, by contrast, seeks to burst this bubble—not as one would expect, by following the path of recent critiques of Kant’s problematic racism, antisemitism, or complicity in European colonial thinking. Rather, he argues that the supposedly secular philosophy of universal reason that should provide the foundation for a rational world order was in fact a new philosophical religion and was perceived as such by his contemporaries.

Willaschek’s book has received numerous glowing reviews, particularly in the leading cultural magazines and feuilletons in both the German and the Anglophone press, and for good reason. It is a good book: well written, clear, and accessible. It does a superb job of presenting an up-to-date orthodox view of a Kant who speaks to the world today. It shakes the cobwebs off a supposedly fusty eighteenth-century philosopher, revealing the man behind the works, and those of us who write on the period should be grateful that there are books such as this to demonstrate to skeptical friends, neighbors, and 20-year-old students that understanding the period, and the German Enlightenment in particular, is vital today. At times it is hard to tell if reviewers’ positive assessments are commenting on the book or on Kant himself. So well does Willaschek present the best case for Kant’s achievements that the line is not easily drawn between his account of Kant’s ideas and the ideas themselves. The goal of this review will not be to spoil the party, but to ask what it holds for historians and scholars of Central European history, and what a more measured, removed vision of Kant and his works might contribute to our understanding of the man and his era.

The book is structured around five major parts (plus a concluding section), each part with several chapters of about 10–12 pages each. These chapters are very digestible and make for easy reading. The German original appeared with CH Beck (2023), a publisher of well-received trade books written by prominent German academics marketed to Germany’s Bildungsbürger. This initial audience explains the rhetorical strategy of many of the early sections of the book. It is admirably translated by Peter Lewis into lucid English prose. Quotations from Kant’s work refer to both the authoritative Berlin-Brandenburg Academy edition (of which Willaschek is the general editor) and the standard Cambridge Edition of the Works of Immanuel Kant in Translation. Parts I–V treat, respectively: Kant’s political theory (including education and his thoughts on Enlightenment and progress); morality and moral autonomy; his social and religious theory (including his cosmopolitanism and thoughts on property); his anthropology, psychology and cosmology under the rubric of “Humans as a Part of Nature”; and finally metaphysics and the limits of knowledge. This structural and narrative choice has its strengths and weaknesses, depending on one’s perspective and agreement with Willaschek’s interpretations. For the lay reader, it has the great advantage of drawing one in through more relatable questions of international politics and morality, before moving on to topics that require much more historical contextualization (eighteenth-century religion, anthropology, and natural science) and saving the most abstruse (metaphysics and the limits of reason) for the end.

The intellectual range of the book is impressive. Willaschek’s knowledge of Kant’s oeuvre is unparalleled, and he deftly weaves the philosopher’s words into every chapter. Another strength of the book is its thematic rather than chronological arrangement. But this structure, at least for the earlier sections, is also a weakness, at least when considered from the point of view of intellectual history, because there is little room for historical development. More problematically, this peristaltic style lets the author indulge multiple levels of apology for Kant’s most unfortunate positions, utterances and stances and perhaps places too much pressure on him to justify the Enlightenment as a whole in the person of Kant. Willaschek employs multiple cross-references to where the problematic issues, such as antisemitism or racism, are discussed more at length. By no means is he trying to conceal Kant’s most problematic views. But Willaschek’s reliance on cross-referencing means that these important points are de-contextualized within individual book sections and not always confronted head-on.

This presentation style changes, however, in the last substantive section (Part V, on metaphysical knowledge), which is also the strongest. For here, Willaschek really does take the time to contextualize the development of Kant’s fundamental innovation in metaphysics and epistemology against the backdrop of the theories and works of Gottfried Wilhelm Leibniz, Christian Wolff, David Hume, and others. In this last section, Willaschek does not try too hard—as in the earlier chapters on politics, race and morality—to present Kant as modern or excuse his outmoded or offensive thoughts. Instead, Willaschek acknowledges that historical epistemology is inherently difficult to explain, and he does so in exemplary fashion.

The book is not intended as a replacement for Manfred Kuehn’s excellent Kant: A Biography (2002), to which the reader is often referred. While Willaschek fills out the philosopher’s life with details about his family, friends, social life and habits (and surprisingly large net worth toward the end of his career), the overwhelming focus is still on the ideas and writings. He opens by invoking three revolutions that characterize Kant’s life: his “volte-face” to becoming a political and ethical thinker in the 1760s; the “revolution in thinking” Kant effectuated with his claim that the structure of our minds shapes our perception of the world and not vice versa, a claim that reached its first mature expression in the Critique of Pure Reason (1781); and the French Revolution, which radicalized his political thought from the 1790s on.

Willaschek writes that Kant’s philosophy mediated two “opposing trends in Western philosophy” that stretch back to antiquity, through the medieval scholastics into early modernity. While his account is as clear as any textbook and generally sound, in its efforts to present complex philosophical stances on objectivism and subjectivism, he sometimes too easily invokes simplistic analogies such as comparing the latter two positions to contemporary “religious fundamentalism” and “superficial cultural relativism,” without really explaining what those are. (9)

A similar tendency to simplify in the name of establishing Kant’s contemporary relevance is apparent in the ways Willaschek turns his account of the philosopher’s famous essay Perpetual Peace (1795) into a brief for the effectiveness of the United Nations and, more problematically, the League of Nations. There is too much water under the bridge for this to be a serious scholarly argument. It is not false, but also not really true either. Moreover, this argument does not take into account recent interpretations of the League of Nations that see it as a perpetuation of European colonial supremacy. Willaschek’s sometimes glib association of Kant with liberal internationalism leaves it vulnerable to questions of value.

Willaschek also fails to convince when discussing Kant’s attack on Moses Mendelssohn’s critique of progress. Kant famously admitted that transforming Judaism into a rational religion would be tantamount to the “euthanasia of Judaism.” Willaschek condemns the antisemitic sentiment yet somehow turns it into an argument for Kant’s idea of progress, arguing that even someone “as astute and critical as Kant” was unable to escape the prejudices of the day. (34)

A similar pattern is apparent in the author’s approach to Kant’s racism—for example, as articulated in his 1775 “On the Different Races of Human Beings”—which he condemns but also tries a little too hard to excuse for not being “modern.” Willaschek observes that there are three prevailing views on Kant’s racism: first, it is a regrettable but historic prejudice that nonetheless does not impugn his basic ethical theories; second, that his philosophy was thoroughly racist, and that Kant’s version of autonomy really only applies to Whites; and third, that Kant changed his mind in the 1790s. Willaschek seems to choose a mix of options 1 and 3. He writes that Kant should have known better, since he understood how prejudice works (138). He presents Kant as a pioneer of globalization and cosmopolitanism who only voiced anti-colonial sentiments in his later political theory, even while maintaining Eurocentric views of racial and civilizational hierarchy. Due to his stature, the influence of Kant’s “epigenetic” theory of racial formation was particularly pernicious and damaging. Gliding over these issues makes other claims, such as Kant’s theories providing a source for contemporary debates about postcolonial restitution, particularly jarring. Abstracted from historical context, Kant’s political philosophy may indeed provide intellectual justification for beneficial international legal theories and actions. But intellectual historians and those aware of the complex history of legal reform in the centuries following Kant will find such pronouncements unsatisfying.

A final example of the book’s elision of recent contextual and nuanced histories of the German Enlightenment relates to his treatment of religion and the notorious Edict on Religions of 1788. The characterization of Johann Christoph Woellner, minister of justice and spiritual affairs, as a “sworn enemy of the Enlightenment” is rather simplistic and ignores decades of scholarship on the varieties of Enlightenments, which include not just Kantian liberalism or materialist atheism, but also conservative and religious strains of which Woellner can be considered a representative. Willaschek’s handling of religion is awkward (though he insists, contra Manfred Kuehn, that Kant was not an atheist) and often ahistorical—for example, when he characterizes Kant’s use of anti-Catholic formulations as somehow “ecumenical.” (164)

Despite these shortcomings, this book is well worth reading. While intellectual historians may lament some of the decontextualization and lack of nuance, Willaschek’s lucid guide to the orthodox liberal interpretation of Kant is nonetheless valuable to have at hand.

How different is the Kant we meet in Ian Hunter’s The Kantian Religion! In Rival Enlightenments: Civil and Metaphysical Philosophy in Early Modern Germany (2001), Hunter observed that philosophical historiography has cast Kant as the solution to a problem—that he had harmonized two intellectual traditions in the early Enlightenment between civil philosophy (which lacked grounding in universal reason), and Wolffian philosophy (which was grounded in reason but vulnerable to Humean skepticism). By rooting knowledge in the structure of our minds instead of the external world and then showing how morality too could emerge from this new version of reason, Kant had “saved” the Enlightenment. Instead, Hunter argued, this success story was in fact a suppression of an eclectic philosophical tradition, and that a rival civil Enlightenment tradition forged by Samuel Pufendorf and Christian Thomasius intentionally avoided the question of universal reason in favor of an immanent, secular rationality intended to avoid sectarian supremacy. In aiming to separate theology from politics and law, Pufendorf’s civil philosophy sought the destruction of Protestant scholasticism. In focusing on the persona of the philosopher, Hunter’s innovative approach in that book was to examine the “ascetic” or self-transformative work that philosophers performed on themselves. He argued that there existed rival intellectual cultures (paideia) meant to form the disposition of philosophers and jurists of increasing importance in the post-Westphalian secular state.

The Kantian Religion serves as a bookend to Rival Enlightenments. Kantian philosophical hermeneutics, Hunter argues, concealed the historical emergence of Kantianism. He argues first that Kantianism was a philosophical religion, formed from historical sources and not from timeless principles of universal human reason available to anyone upon reflection and introspection. Kant’s notoriously difficult language and intellectual exercises in the first two critiques served as ascetic practices for “spiritual athletes” and were intended to form the right disposition for a new generation of philosophers who could supplant the traditional roles of Germany’s clerical elite. Having grounded his interpretation in a close reading of the philosopher’s work and its intellectual sources, Hunter next—in a series of revelatory chapters—shows how Kant’s philosophical religion was perceived precisely as such by contemporary Lutheran, Catholic, and Jewish thinkers. In Hunter’s account, there is no “elegant magister,” no charming stories of Kant and his social scene. There is little to no discussion of the major controversies of the day, such as the question of “the fate of reason” unleashed by the Pantheism controversy, and the French Revolution barely raises its head. Rather, Hunter goes straight for the ideas, dissecting them with a scalpel before smashing them with a sledgehammer.

This book is based on a series of difficult but necessary technical arguments. These will be best judged by readers well-versed in the arcana of Kant’s difficult and rigorous language, especially concerning the transcendental deduction and the transcendental dialectic in the Critique of Pure Reason, and archetypical intellection of the moral law in the Critique of Practical Reason. Hunter’s overarching point is that—regardless of their philosophical or logical truth values—they prima facie (because of their difficulty) are a kind of intellectual gymnastics or psychagogy (Seelenführung). As an intellectual historian, this reviewer is predisposed to be convinced by his argument. But because they offer such a direct challenge to a firmly established professional philosophical literature, this review will not offer a final word of adjudication. Instead, the aim of this review is to present the structure of Hunter’s argument and its significance for the intellectual history of the period, underscoring its methodological challenge to histories of philosophy. Hunter’s argument is exceedingly clear but requires close attention. As such, this is a book for specialists and advanced readers, but also one that promises to make a deep impression on the field and enjoy a long shelf life.

Parts I–III relate to Kant’s theoretical, moral, and religious philosophy, respectively. Kant’s “Copernican Revolution,” Hunter argues, is not self-evident. It demands a suspension of common sense and requires an initial ascetic practice that can only be performed by a select cohort of adepts. It also presumes the divided nature of human beings into their sensible and rational natures, an image dependent on Christian-Lutheran metaphysics. (21) Through an extremely close reading, Hunter argues that the transcendental deduction—his derivation of the conditions of the possibility of experience by which our minds experience the world—serves as a practice of self-clarification. The transcendental dialectic—Kant’s parade of the paralogisms and antinomies of pure reason—Hunter argues, serves as a kind of philosophical therapy leading to a “cathartic epiphany” in which the philosopher reaches a state of inner equipoise after cycling through irreconcilable intellectual positions. In Part II, Hunter traces the sources of autonomy in Kant’s moral philosophy to intellectual intuition of an archetypical humanity, of which actual humans are corrupted ectypes (or imperfect copies). Morality is thus not about the law, but about the philosopher’s inward relation to his own concealed higher self.

In Part III, centered on Religion within the Boundaries of Mere Reason (1794), Hunter argues that Kant perceives two paths to pure moral religion: ascetic intellectual exercises for the elite and a new biblical hermeneutics for everyone else. (261) In uncovering a pure moral religion hidden within the core of Biblical Christianity (in reality, Protestant ecclesiastical history and theology), Kant assumes the serendipity of the bible—it just happened to contain the core of pure moral religion that was only properly excavated in Kant’s own day. This view, Hunter points out, entirely ignores the humanistic historical and philological biblical studies that had reached such maturity in the eighteenth century and were particularly associated with Göttingen scholars such as Johann David Michaelis and Johann Gottfried Eichhorn. Pointedly, Kant’s vision ignored—almost aggressively so—the Jewish-Christian link established by humanist biblical history and philology, a dangerous development, as noted later by Jewish thinkers such as Saul Ascher and Moses Mendelssohn. (285–6)

Part IV is almost an entirely new work—in both tone and argumentation. If any reader were skeptical about Hunter’s reading of Kant’s philosophical religion and ascetic practice, his exploration of its reception by Kant’s contemporaries—by Lutherans, Catholics, and Jews, as well as by the early absolute idealists—shows that they understood him in precisely this way. The initial reception of Kant’s philosophy took place almost entirely within the culture of German Lutheranism—that is, the upper-level educational strata in seminaries and universities that focused on the training of clergy. (293) This Lutheran reception seemed natural enough, given that Kant’s model of human nature was rooted in a Lutheran/Pietist dual nature of mankind as sensible and intellectual. (The idealists, incidentally, were wrong to perceive this as an error to be “fixed” in Kant—for Hunter, the split is the core starting point for the Kantian askesis.) There were various factions, however, within Lutheranism, even though externally it was largely regulated by the common doctrines of the Formula of Concord. In the 1780s and 90s, complex and competing strains pushed the boundaries of this intellectual and religious culture, including strains of Leibnizian and Spinozistic philosophy, Wolffianism, Pietism, and Enlightenment theology (neology), as well as a rich historical and philological biblical criticism and ecclesiastical history. To many early adopters, Kantianism promised to supersede these rival intellectual currents through a pure religion of reason. And while young hotheads—especially the talented minds in the Tübingen Stift such as Hegel, Hölderlin, or Schelling—excitedly embraced the new philosophy as an answer to the intellectual contradictions they experienced, important factions among their teachers saw the danger. Hunter offers revealing accounts of the anti-Kantian efforts of Gottlob Storr and Christian Wilhelm Flügge. The latter portrayed Kantianism as playing a role similar to neo-Platonism in early Christianity or Thomism in the medieval Church—as a philosophy that eschews pluralism and seeks a role as the dominant interpretation. (314)

Hunter’s account of Kant’s Catholic reception shows in the clearest relief the function of Kantianism as a rival school philosophy for a religious system—one that linked doctrinal commitments to a series of spiritual grooming practices. The Catholic reception was factional, shaped by religious orders and ecclesiastical geography and governance. Attention to the Catholic reception of Kant is revealing because it throws into relief the felt need for a school philosophy, and what happened to an academic-religious culture (in which the training of clergy as intellectual and religious mediators was crucial) when its institutional pedagogy is shaken by outside forces. Jesuit Thomism did not fall because it was weak inherently, but because of the suppression of the Society of Jesus in 1773. Catholic seminaries and universities needed both a new teaching corps and a new school philosophy. Kantianism was there for the potential taking. And some Catholic theologians did indeed try to adopt or adapt it, even if Kant’s Christology was a bridge too far. Ex-Jesuit Benedict Stattler’s wholesale rejection shows how contemporaries recognized Kantianism for what, in Hunter’s view, it really was: a rival religious system.

Finally, Hunter’s account of the Jewish reception is as revelatory as it is sobering. Key Jewish thinkers clearly saw that Kant’s religion of pure reason was nothing other than a philosophical reincarnation of Christian supersessionism, the doctrine that Christianity has taken the place of Judaism in the covenant with God. The Jewish reception also occurred in a more haphazard fashion, that is, by individual scholars and teachers at the margins of Jewish society. Judaism did not have the same institutional system equivalent to Catholic and Lutheran universities, seminaries, or orders, which required state recognition, constitutional protection, and significant financial resources. Its intellectual culture was rooted in rabbinical commentary and scriptural study. Moses Mendelssohn saw Kant’s call for natural religion as a masked conversion test for Jews seeking citizenship. Saul Ascher (whose pamphlet Die Germanomanie would be burned at the Wartburg Festival in 1817) argued that by elevating Christianity as a religion of reason in nuce, Idealism and Kantianism had legitimized Jew-hatred. Kant was not the major source of antisemitic sentiment, but read this way, his philosophy allowed it to flourish in new ways.

One minor objection to his historical contextualization: does Hunter overemphasize imperial law? While its formulation in the Westphalian settlement does provide a useful heuristic and historical definition of religion and desired limits on confessional proselytism, there is little evidence that Prussian leaders were concerned about religious civil war or imperial sanction. Why could not a state Church determine its own theological direction—as indeed they did, even aside from Kantian philosophy. Yes, one could characterize the infamous Woellner Edict as merely enforcing the Westphalian Settlement in the interest of religious peace. But given that the Frederician state had tolerated and then actively encouraged the flourishing of enlightenment theology (“neology”) for decades, the issuance of the edict upon the change of regime seems more likely in response to the concerns of the Prussian state, not pressure imagined or real from imperial courts.

As Markus Willaschek notes, the annual Kant bibliography lists some 700 to 1000 new publications. Among them, these rival interpretations of the philosopher stand out for their relevance and lucidity. Willaschek’s accessible and masterful overview will be of great value to a broad range of readers, while Hunter’s forceful polemic will no doubt generate vigorous discussion for years to come.