Baumgarten’s practical philosophy has recently seen a revival. Given Kant’s long reliance on Baumgarten in his lectures, scholars seek a concise account of that influence. Key questions include the following: the sources of the categorical imperative and ‘universal practical philosophy’; the distinctiveness of Kantian obligation and why duty is often met with reluctance; whether Kant is a moral realist and how Baumgarten shaped that stance; Kant’s retention of ‘duties of religion’ despite denying ‘duties to God’ and the explanatory role of Baumgarten; the disagreement over whether conscience can err; the meaning of imputing actions and Kant’s indebtedness to Baumgarten on imputation; the notion of self-perfection and the inner/outer distinction; and finally, whether Baumgarten offers a just-war theory that sheds light on Kant’s view of right.
Baumgarten and Kant on the Foundations of Practical Philosophy offers a rich and wide-ranging exploration of these questions. While the book focuses mainly on Baumgarten’s Elements of First Practical Philosophy, which Kant used in his ethics lectures, it also examines Baumgarten’s Philosophical Ethics, an equally important source for understanding the development of Kant’s ethics. The volume is thus valuable primarily not only to Kant scholars interested in the genealogies of his ideas in practical philosophy but also to those concerned with contemporary debates informed by Baumgarten’s thought. Yet this richness is often obscured by Kant himself in his critical appropriation of Baumgarten – a problem the editors, Courtney Fugate and John Hymers, are well aware of (p. 2).
The book comprises the editors’ introduction and 13 chapters on key moral concepts – central to Baumgarten’s practical philosophy yet often unfamiliar to contemporary readers – such as perfection, necessitation, imputation, duties of religion, conscience, and the role of ‘right’ in his thought and its influence on Kant.
The opening chapter situates Baumgarten’s ethics – a branch of practical philosophy – in its historical context and outlines his fundamental concepts of obligation and duty in relation to Kant. Clemens Schwaiger underscores the urgency of studying Baumgarten’s practical philosophy, especially his ethics (pp. 17–19, 29), for readers in the English-speaking world and beyond, offering a fresh perspective despite the chapter’s prior availability in German.
In Chapter Two, Stefanie Buchenau traces how the mathematical model of philosophy, for which Wolff is known, passes from Wolff through Baumgarten to Kant in their practical philosophy. She emphasizes Baumgarten’s criticism of Wolff’s model and argues that Kant consolidated Wolff’s and Baumgarten’s projects of philosophia practica universalis, refining them into his metaphysics of morals (p. 56). Buchenau offers a more nuanced interpretation of the mathematical thread in Kant’s practical philosophy than the prevailing model, which has relied chiefly on Wolff.
In Chapter Three, Heiner Klemme examines the historical development of the distinction between necessity and necessitation (pp. 62–4), tracing its genealogy from Leibniz to Kant. In clarifying necessitation within each philosopher’s framework, he explores how Kant and his predecessors conceive moral obligation through this notion. Klemme also shows how Kant’s practical philosophy, grounded in pure reason, departs radically from the tradition of universal practical philosophy that preceded him (pp. 60–1).
In Chapter Four, Sonja Schierbaum and Michael Walschots compare the notion of obligation in Wolff, Baumgarten, and Kant. Building on the previous chapter’s theme, they examine in greater detail the distinction between necessity and necessitation in Baumgarten and how it sheds light on Kant’s conception of obligation in its historical context, showing how Kant defends freedom and choice against Wolff’s and Baumgarten’s psychological determinism (pp. 84, 89). The chapter also stands out for its treatment of constraint and reluctance in fulfilling obligation as Kant understands it and how this differs from Wolff’s and Baumgarten’s views.
Chapter Five, by Stefano Bacin, explores a key tension in eighteenth-century German philosophy: that between realism and rationalism (pp. 95, 104). Bacin examines this through the further tension between subjective and objective dimensions of morality in Baumgarten’s Elements. Central to his analysis is Baumgarten’s turn to subjective morality, marking his departure from his Scholastic heritage, though he retains objective morality. The chapter’s highlight is Bacin’s insight into Baumgarten’s moral realism – his unique notion of objective morality that accommodates subjective morality – and its impact on Kant.
In Chapter Six, Gualtiero Lorini offers an intriguing interpretation of how Baumgarten’s notion of self-legislation influenced Kant’s version. He argues that Kant’s moral theology owes more to Baumgarten than generally assumed. According to Lorini, while Kant ultimately rejects Baumgarten’s ‘doctrine of duties to God’, he retains reference to God because he views morality as fundamentally pointing to this notion (p. 127). This chapter contributes to the growing literature on Kant’s philosophy of religion by shedding new light on its precursor.
Allen Wood’s chapter addresses key philosophical tensions between Baumgarten and Kant regarding moral judgement, imputation, and conscience. Kant views imputation technically, treating a deed as always falling under obligation. In contrast, Baumgarten allows degrees of imputation, emphasizing how and under what conditions the agent understands the deed (p. 131). Wood carefully explores Kant’s nuanced shift in the latitude imputation permits, shedding light on differences in conscience’s latitude between the two philosophers. Given this, Wood concludes that Kant’s claim of conscience’s infallibility should be understood as conscience issuing the final verdict on a deed, beyond which no appeal is possible (pp. 132, 135–40).
Alexander Aichele’s chapter offers an in-depth analysis of imputation in Kant and Baumgarten, examining how practical norms are identified and applied in action. Aichele explores Baumgarten’s influence on Kant’s notion of practical norms, highlighting its significance through comparison with Baumgarten’s version. The chapter concludes by emphasizing what Kant’s focus on moral imputation and exclusion of physical imputation mean in light of Baumgarten’s inclusion of physical imputation in his practical philosophy (pp. 151, 155–8).
The next chapter, by Paul Guyer, refines his earlier work on Kantian perfectionism (Guyer Reference Guyer, Jost and Wuerth2011) by incorporating Baumgarten’s concepts of general and self-perfection. This chapter serves as a transition to the book’s later section on political philosophy, linking the foundation of morality to the right of humanity understood as preservation of inter- and intra-personal relations (p. 172).
In Chapter Ten, Courtney Fugate highlights Baumgarten’s unique perfectionism, which transforms the pre-Kantian tradition and sets the stage for Kant’s mature moral theory. Fugate’s key contribution is showing how Baumgarten’s innovations influence Kant’s later development. Baumgarten differs from Wolff in several ways: he retains some Leibnizian doctrines Wolff rejects or downplays; he develops a new ontology offering a mathematically precise account of degrees of perfection, unlike Wolff, who is usually known for his mathematical method, and, unlike Wolff, Baumgarten holds that something is good by being perfect even in isolation from nature (pp. 189–97). Fugate argues that understanding these differences enhances our grasp of key Kantian concepts like virtue, moral law, and the kingdom of ends.
The eleventh chapter explores the difference between the adjectives ‘inner’ and ‘outer’, fundamental to Kant’s conceptions of freedom and law. Frederick Rauscher shows how Kant structures his practical philosophy around this contrast found in Baumgarten’s Elements. Rauscher identifies ten distinctions between inner and outer in Baumgarten (pp. 204–8), summarized into four key features: inner as natural vs. outer as contingent; inner as a material result of internal law vs. outer as from external law; inner as one’s own choice vs. outer as another’s choice; and inner as occurring in the soul or mind vs. outer as physically expressed (p. 208). Using this framework, Rauscher analyses Kant’s reconfiguration of practical philosophy’s divisions – such as right and ethics – highlighting categories like the good in general, private good, and duties to oneself and others, and identifies an overarching structure for them.
Chapter Twelve examines the concept of natural right, comparing the theories of Baumgarten, Achenwall, and Kant, and offers an original interpretation of Kant’s solution to the ambiguity between juridical and ethical principles. For Baumgarten, the principles of right are not qualitatively distinct from those of ethics (p. 228). Achenwall, by contrast, defines strict right as the moral capacity to coerce (p. 229). Tracing the development of the notion of natural right up to Kant, Fiorella Tomassini makes a bold claim: Kant finds Achenwall’s doctrine more effective in delimiting juridical duties and justifying coercion in these duties – something Baumgarten fails to do (p. 239). Those interested in Kant’s doctrine of right, particularly in relation to Achenwall, will find much to study here.
In the final chapter, John Hymers presents an original account of Baumgarten’s theory of war and peace – something virtually untouched in previous research, apart from Osawa (Reference Osawa, Schierbaum and Schotte2024a). Hymers argues that contemporary just-war theory has roots in Baumgarten’s thought, a bold challenge to the prevailing view that Kant is the intellectual father of the UN (pp. 266–7). Drawing on an unparalleled command of Baumgarten’s practical philosophy, Hymers brings to bear his intimate knowledge of the Elements and Philosophical Ethics – works he has translated (the Elements with Courtney Fugate) – and, most notably, the Ius naturae, which has received little serious attention. This gives his argument exceptional depth, and readers will find Baumgarten’s contemporary relevance convincingly demonstrated.
Much more could be said about these chapters, and the summaries here hardly do justice to the breadth and depth of their arguments. In conclusion, let me turn to three issues that seem to me especially worthy of further attention.
First, one concern is the contributors’ relative unfamiliarity with Baumgarten’s Philosophical Ethics, except for Hymers. Readers will find Baumgarten’s fuller accounts of concepts discussed in many chapters – such as duties to God, an erring conscience, and self-perfection – in that work. Chapters addressing these notions would benefit from fuller discussion that considers Baumgarten’s treatment in Philosophical Ethics.
Second, although most contributors focus on fundamental moral issues such as the nature of perfection and moral necessitation, essential questions about moral life fall outside the book’s scope. These include the following: What does it mean to love humanity itself, and how does this differ from affection for those close to us? How do love and respect relate, and why might excessive love be problematic if unchecked by respect? Why are we sometimes prone to believe what is false and act on that misconception? Kant scholars will recognize these as issues Kant addresses in his moral writings. Since Baumgarten also engages them, especially in Philosophical Ethics, Kant scholarship would benefit from fuller engagement with and refinement of these questions in light of his influence.
Third, a further concern is the heavy reliance on Kant’s diagnosis of Baumgarten. Tomassini claims Kant holds that Baumgarten fails to distinguish right from ethics, but she supports this mainly by citing Kant’s own diagnosis (p. 228). Admittedly, the principle of right is part of Baumgarten’s broader ethical project, and he does not clearly define its relation to ethics. Yet, if we attend to the distinction between right and virtue in Baumgarten – the latter being another element of his ethics alongside right – we may need to reconsider Kant’s flat dismissal of Baumgarten’s failure to distinguish the two.
Despite these concerns, the book offers an engaging introduction to Baumgarten’s practical philosophy, largely neglected in previous research apart from some contributors’ earlier work and another recent study from a different angle (Osawa Reference Osawa2024b). It demonstrates the relevance of these views for refining our understanding of Kant’s practical philosophy, given his nuanced appropriation of Baumgarten despite his seemingly blunt dismissal.
