Some of these topics have been treated before, but others remain nearly unknown, at least in the Anglo-American realm. There is a growing literature on so-called early modern natural law theory, but eclecticism as a philosophical method has received little attention in English. Moreover, the many histories of morality that appeared (mainly in Latin) during the late Seventeenth and early Eighteenth centuries are even less familiar, both individually and as a pervasive intellectual phenomenon sui generis. Hochstrasser is the first to tackle this body of work and to expound its historical and philosophical significance.

The book contains six chapters whose rich detail might have been better reflected in an expanded table of contents. Chapter 1 establishes the connections among the main themes: natural law, eclecticism, history and theory, and the influence of debates about these topics on university reform and the politics of enlightened absolutism. It ends with an appendix listing the main “histories of morality” consulted. Chapter 2 examines Pufendorf's intellectual method and intentions, particularly his Specimen controversiarum (1678), which was the first and, indeed, paradigmatic instance of moral historiography in the service of philosophical argument. The third chapter compares Leibniz and Pufendorf, not merely their famous disagreement about the nature of obligation but also the underlying moral epistemologies that determined their respective intellectualist and voluntarist approaches.

In chapter 4, Hochstrasser details the metamorphosis of Pufendorfian jurisprudence in Christian Thomasius and his school, including the formal commitment to eclecticism as a self-critical intellectual method most suited for practical reforms. Chapter 5 shows how Wolff and his followers (including Vattel) transmuted voluntarist natural law into rationalist, metaphysical forms directly opposed by its founders. It also describes how the melding of rationalist and voluntarist traditions in Brucker's influential history of philosophy began, already, to obscure the important role of Pufendorf and Thomasius. The final chapter traces eclecticism into the Popularphilosophie of Meiners and Garve, explores Kant's understanding of the history of philosophy, and clarifies the inhospitality of pure reason to natural law as such. Moreover, it iterates the continuing linkage between these abstract discussions and more worldly contestation over academic disciplinary status and, indirectly, social policy. The chapter ends with a look at the Kantianized histories of moral philosophy by Stäudlin, Buhle, and Tennemann, in which natural lawyers and eclectics are barely noted and, ironically, their work is mistaken for the neoscholastic, quasitheological orthodoxies that they opposed.

The sheer range of this book and its ability to fold such a variety of intellectual developments into a coherent account are its chief recommendation. Several features deserve specific mention as notable contributions to the scholarly literature. One is Hochstrasser's careful analysis of the so-called Bineburg correspondence. This important epistolary exchange in the early 1660s—among the German constitutional lawyer Hermann Conring, Baron von Boineburg (Leibniz's patron at Mainz), the Grotian expositor J. H. Böcler, and Pufendorf—resulted in the latter's abandonment of a formal, quasimathematical method for one argumentatively more engaged with historical predecessors. There is nothing as detailed and informative in the English literature, and Hochstrasser's treatment sets a high standard for such background studies, which are so necessary for understanding the evolution of ideas.

Another feature is Hochstrasser's excellent articulation of Pufendorf's sociality principle in terms of his empirical account of language acquisition and the associated development of human rationality through a socialized cultura animi. This, too, is an unusual and powerful focus that shows Pufendorf to be about twenty years ahead of Locke (in his opposition to innatism and his analysis of complex, abstract ideas), and it rightly exhibits the contingency at the heart of Pufendorfian natural law that so irritated his theological, rationalist, and (later) even transcendental opponents (i.e., Kant), who were all absolutists in their own way. By noting the dependence of (even) language and rationality upon a kind of double contract (consistency, veracity) similar to that grounding the state (association, submission), it exhibits well the experience-based conventionalism, or controlled voluntarism, that elaborates the meaning of sociality at different levels of Pufendorf's natural law framework.

Some of Hochstrasser's concepts and distinctions still need sharpening. The notion of “imposition” in Alberti and Pufendorf, and in the divine and human instances (even among humans), is not quite the same. The claimed divergence of ethics from natural law and international law—a result of these debates—also depends on particular interpretive commitments whose potential divergence is not always noted. Even the central notion of voluntarism seems philosophically underdetermined at times, as Hochstrasser moves from the voluntarism “excluded” (p. 104) from Pufendorf's moral epistemology to Kant's “frontal assault” (p. 198) on the voluntarist moral histories in which Pufendorf was central. Ironically, this problem arises because Hochstrasser, unlike the histories he canvasses, may be too historical and insufficiently philosophical. That is, he sometimes takes thinkers or ideas too much on their own or their respective expositors' terms. Yet, without a stronger interpretative or philosophical preference, also reflected in a consistent terminology, the narrative gets redefined too often, and the reader winds up conceptually stranded, without a general vantage point.

The problem is occasional, however, and does not undermine the intelligibility brought by this excellent study to an historical period still lacking in plausible panoptic perspectives. The work rests on a wide and deep scholarship conversant with the primary and secondary literature in many languages. It is well written and carefully produced, and it will become an important tool in the field.