Roger Berkowitz's The Gift of Science is about the genesis and development of legal codification from its birth in Gottfried Wilhelm Leibniz's work to the German Civil Code of 1900. Leibniz's legal writings have been long neglected and this study is to be commended for bringing these writings back to our attention. Berkowitz charts the development of Leibniz's legal thought from his early to mature writings, illuminating Leibniz's surprisingly helpful reflections on the nature of law.

Berkowitz makes some highly controversial claims throughout. For example, he tells us that positive law is “the thesis that law has its ultimate source in will, not reason” (pp. xiii, 4, 21). Berkowitz continues, “Since positive laws are grounded in nothing but the willful command of a sovereign, they are often denigrated as arbitrary and irrational” (p. xiii). With this understanding of law, Leibniz is claimed to be a positive lawyer. Yet, this reading goes against the standard categorization of Leibniz by Leibniz scholars and presumes a controversial understanding of the dichotomy of positive and negative law (p. 7). Instead, positive lawyers endorse the separability thesis. This thesis is that morality and law are strictly separable. Berkowitz provides no argument for why we should jettison this now universal and conventional understanding of positive law, let alone why it should be replaced with the model he proposes in its place.

Berkowitz also introduces a questionable dichotomy between natural law “grounded in reason” versus positive law “posited through legislation” (p. 22). Why think the two are different projects? This was certainly not the case for natural lawyers who, at least since Kant, have argued that natural law is both grounded in reason and certainly capable of inclusion in positive law (e.g., see Thom Brooks, “Kant's Theory of Punishment,” Utilitas 15 [no. 2, 2003]: 206–24). The thought is that natural law serves as a measure of appraisal by which we assess our positive laws, with the aim of making our positive laws commensurable with natural laws. From this standard natural law perspective, positive and natural laws then can be seen as intertwined in the same project. Strangely, Berkowitz seems to acknowledge this point a few pages later (noting, “Both natural and positive right condition and determine one another”), leaving the reader puzzled as to why he would have thought otherwise shortly before (pp. 24, 49). Perhaps oddly, Berkowitz claims that Leibniz is both “a natural lawyer” and the founder of modern legal positivism (p. 7). This is especially odd when his legal distinctions are, in Berkowitz's view, “a division of natural law” arising from the wisdom of God as its original source (p. 65). Given the inconsistencies in Berkowitz's radical reinterpretation of what exactly positive (and natural) law is, readers will find it difficult to follow his argument.

Leibniz's main contribution, for Berkowitz, was to view law as a product of science. A product of science is “willed, posited, and in need of scientific justification” (p. xv). That is, law as science is not merely a project concerned with improving law's “accuracy,” as it were. Instead, law is a product of will enshrined in legal documents. This is rather unhelpful as Berkowitz fails to satisfactorily explain precisely how this process should unfold. Indeed, it is almost shocking that Berkowitz seems to view Leibniz's understanding of “science” in contemporary Anglo-American terms, rather than in terms of the very specific understanding of “science” held by Leibniz and his German contemporaries, where science is Wissenschaft (often understood by writers of the time as a form of systematic examination of some topic), implying a different understanding of science and precision.

In any event, Berkowitz claims that Leibniz's attempts at linking science with an understanding of law are entirely novel. Yet this is not convincing. For one thing, Thomas Hobbes was making such claims decades before Leibniz. Berkowitz tells us that “Leibniz was the first jurist to think about law as a product of modern science,” developed from Leibniz's reflections on mathematics from “the 1670s” (p. 19). However, Hobbes was grounding a theory of law and the state based upon his understanding of geometry in the Leviathan in 1651 (and earlier works). It is certainly true that of the two, only Leibniz promoted legal codification. However, this innovation (if Leibniz's) appears far less noteworthy when his contributions are seen in their full context, including Hobbes's work in the background. Indeed, it is quite clear that Leibniz had some familiarity with Hobbes's work, and it is perhaps unsurprising to find both adopting a geometrical method for thinking about law, with Leibniz attempting to move beyond this method (pp. 41, 43, 46–48).

The purpose of The Gift of Science is not merely to say something new about Leibniz's legal philosophy but demonstrate its lasting influence. In this regard, the book does not succeed. The story seems to be that in eighteenth- and nineteenth-century Prussian and then German legal thought, we find the origins of modern codification. Leibniz's contribution to this? His emphasis on a link between positive law and natural justice (pp. 82–83). Yet if anything, the development of German legal codification appears to have taken a number of quite different developments away from Leibniz's views and toward the advances suggested by Kant, as Berkowitz appears to acknowledge (pp. 84–85, 88–91). However, if the modern German legal code took a radically different shape away from what Leibniz was proposing, then it is difficult to understand precisely where Leibniz's strong influence on this code might lie.

That codification would have been popular in Prussia and Germany is perhaps unsurprising, as codification had existed prior to Leibniz, albeit in a different form than he would endorse. Nor is it surprising to find legal theorists argue that our laws should aim for compatibility with justice, as natural lawyers have argued since at least Cicero. It is difficult to discern in all of this what precisely was Leibniz's distinct contribution. That his views on law differed from others (no matter their general similarities) is clear. However, it is much less clear how his views ever made a major impact on legal reforms either before or after his death, especially given that the kinds of things he has been credited for by Berkowitz (e.g., the scientific approach to the study of law, the endorsement of codification, the defense of natural law, etc.) are all views that had been defended by others before Leibniz. Nor is this surprising for an eighteenth-century Prussia where “few have read” Leibniz's work in legal theory (p. 109).

Overall, I find this book weak on explanation, and what explanations it provides are incomplete or false. That said, it does present an interesting account of Leibniz's views on laws. Given the paucity of work in this area, I recommend it to those keen to learn more about them. Leibniz is a most important figure in the history of philosophy, and we have much to learn from him. Unfortunately, this book fails to sufficiently make clear what this is or why we should study his work on law more closely.