Gottfried Achenwall (1719–72) was a German philosopher, jurist, historian, economist and statistician whose primary academic appointment was at the University of Göttingen. His importance for the development of Kant’s juridical and political thought is uncontroversial, but access to Achenwall’s work for present-day scholars is impeded by the fact that it is written in Latin. This English translation of the fifth edition of Achenwall’s Jus naturae (1763) by Corinna Vermeulen provides an excellent opportunity for a broader readership to explore the text that served as the basis for Kant’s lectures on natural law. The edition helpfully makes it available without requiring specific acquaintance with the peculiarities of the legal terminology of eighteenth-century German academic practice. Along with this valuable translation, the edition includes two prefaces, an introduction, as well as detailed Latin–English and English–Latin subject indices, an index of names and a sketch of topical and chronological concordances between Achenwall’s text, Kant’s lectures and the related references in Kant’s Reflections.

The first preface, by the series’ editors, introduces the impressive project of the series as aiming not only ‘to offer the tools necessary for reconstructing the context of Kant’s thought’ (p. viii) but also ‘to give Anglophone scholars a more comprehensive picture of the intellectual world that made possible the German Enlightenment’ (p. ix). The second preface, by Pauline Kleingeld, argues for the relevance of Achenwall’s text given its importance for understanding Kant’s lectures on natural law and formative influence on Kant’s legal, political and moral philosophy, and on account of Achenwall’s own contributions within the history of legal and political philosophy in general. The preface also gives an explanation for the lateness of the interest of Kant scholarship in a translation of Achenwall as due in part to the relative unavailability, until very recently, of the student notes to Kant’s Feyerabend lectures.

The introduction by Guyer makes the case for how thorough acquaintance with Achenwall’s text can provide a better understanding of Kant’s legal and political theory, especially that elaborated in the Doctrine of Right. After a short biographical sketch of Achenwall, and a description of the specifics of the six editions of Jus naturae, Guyer analyses the continuities and discontinuities between Achenwall and Kant. First, he compares the structure of Achenwall’s Jus naturae and Kant’s Doctrine of Right, outlining Kant’s reformulations of Achenwall’s text (in the difference between innate and conditional natural right, for instance), along with additions (of cosmopolitan right) and departures from it (the distinction between provisional and conclusive natural rights). Second, Guyer attempts to provide an answer to the general question ‘What is natural law or natural right, as Achenwall and following him Kant understand it?’ (p. xix). In order to explain the meaning of (natural) law and (natural) right, he focuses on Achenwall’s division between perfect and imperfect obligation, where the former implies coercion and the latter does not. His conclusion is that ‘[n]atural law concerns the coercively enforced part of moral law’ (p. xx) (without addressing the important question of the distinction between natural law and natural right) and he claims that on this point Kant is in keeping with the broader natural law tradition, since this distinction is already in Christian Thomasius, or even in Grotius.

With respect to the further question of what makes natural law natural for Achenwall, Guyer offers a more distinctive answer, leaning on the modern development of the tradition of recta ratio, which claims a difference between human reason and divine reason. Although he references Jan Schröder’s understanding of natural right as an attempt to develop a complete system from reason alone, Guyer claims that natural right has a divine foundation, referring to the Institutes of Divine Jurisprudence where Thomasius traces the origin of human reason and human nature to the divine or natural reason. The fact, however, that Schröder refers to natural right, not natural law, is an unmistakable reference to how modern philosophy claims natural right (and, in this respect, moral theory) as a secular theory without a need for external validation of its normativity even if, as considered as a natural law, it is bound to have a divine origin. Without considering this, Guyer concludes that Kant’s achievement is to understand reason without need of external validation, even if Guyer admits that Kant’s position is, to a certain extent, ‘a radicalization of the tendency of the modern natural law tradition’ (p. xxiii).

In the rest of the introduction, Guyer provides a clear account of how Kant refines Achenwall’s theory. He gives three examples: first, Kant’s reduction of natural and innate rights to the right to preserve one’s own freedom; second, his demand of justification for the necessity of coercion; and third, his understanding of marriage (which aims to overcome social hierarchies) and of the relation between church and state (which includes mutual independence from each other in order not only to secure the liberty of every individual but also to secure the freedom of thought and speech, and in this way to enable a society to undergo cultural and intellectual development). In all three regards, Guyer convincingly shows how productive Kant’s engagement with Achenwall’s text was for the refinement of his own theory.

The principal part of the edition consists of the impressive translation of Achenwall’s text by Vermeulen. It is accompanied by helpful remarks regarding the necessity of some improvements to typography or bibliographical entries given by Achenwall, as well as an explanation of how Achenwall’s frequently inconsistent use of technical terms has been dealt with. The translation includes the corresponding pages in the original editions of part I and part II, as well as in the edition of part II published in volume 19 (1934) of the Akademie-Ausgabe of Kant’s works. All this nicely enhances the edition and adds significant value for scholars working on Achenwall’s text.

The topical and chronological concordance, the indices of names and subjects and the Latin–English and English–Latin glossaries fill out the edition. Concerning the concordance, my only criticism concerns the lack of harmonization between the different English translations of the topics in Achenwall’s text and the translation of Kant’s lectures in the Naturrecht Feyerabend. While in both cases the original topics are in Latin, it would obviously be useful if the same terms in Latin were rendered with the same terms in English in both editions. For example, in the last topic of part I, the Latin term in both Achenwall and Kant is lites finiendi, but the English translations differ markedly – it is rendered here as ‘The ways to end a dispute’ as opposed to ‘Of the ways of determining lawsuits’ in the translation of the lecture notes. In general, however, the index is very helpful, as is the concordance which provides the reader with references to Kant’s Reflections on the topics.

All the parts of this edition contribute to a result that has considerable scholarly value. This edition’s focus on Kant is intentional due to the broader scope of the series (Kant’s Sources in Translation). In accordance with the goals of this series, the edition underlines the significance of Achenwall for Kant, focusing on the continuities and discontinuities between Kant and the natural law tradition, where Achenwall’s account is taken as representative of the latter (p. xxii). But the question if, and to what extent, Achenwall’s own account differs substantially from the natural law tradition and, if it does, why Kant chose to base his lectures on it, is left open. In the end, however, the task of the publication is to make Kant’s sources available for research as well as to make explicit Achenwall’s relevance for Kant, not to provide the research itself.

For those interested not only in Kant but also in the history of legal and political philosophy, it would have been helpful to have a more detailed consideration of the specifics of Achenwall’s natural law theory in comparison with others (apart from Kant’s). As Stephan Pütter notes in his history of the University of Göttingen (Pütter Reference Pütter1765: 297), at the same time as Achenwall, Georg Christian Gebauer (1690–1773) held lectures on natural law following Nicolaus Hieronymus Gundling’s (1671–1729) account of natural law, and Gustav Bernhard Beckmann (1720–83) held lectures on natural law following Christian Wolff. This would serve to underline Achenwall’s originality by comparison, in spite of his early reliance on Grotius and Pufendorf. It is in any case to be hoped that the present edition will provide a needed stimulus, and not only for Kant scholars, for more research into the development of natural law theory before Kant.