The main goal of George Duke's Aristotle and Law is to show that Aristotle's scattered comments about law (nomos) are the expressions of a unified conception. This is no easy task. Because Aristotle's claims about law are somewhat sporadic, and because so many of these claims seem in tension with other key Aristotelian principles, Duke must often undertake two interpretive challenges at once. On one hand, he works to show that Aristotle's statements about law are consistent with one another. On the other, he enters into interpretative debates about notions such as nature, natural law, and the common good in order to identify an interpretation that best coheres with Aristotle's thoughts on law. Though ambitious, this makes for a delightful and rewarding work. Indeed, I recommend this book not just to those interested in Aristotle's theory of law, but to anyone looking for a lucid overview of many of the scholarly debates about Aristotelian ethics and politics.

What is Aristotle's conception of law? The core notion is this: law is the ordering of a political community insofar as this is the result of a legislator's using practical wisdom to promote the community's good. Crucially, note what such a notion does not include. Law is not defined in terms of what all citizens can agree to, and it makes no promise of offering reasons for action that all citizens can grasp. Rather, law is something like a tool used by legislators for promoting the good—and this may well involve deploying force against inhabitants who, because of passion, lack of education, or some other cause, refuse to follow (chap. 1).

If, however, the laws that order cities resemble craft-like products, why would Aristotle believe that cities are natural? Duke's answer: in producing laws, legislators are doing something that, in some respects, is similar to spiders weaving their webs. They are not creating a product that bears no connection to human nature; rather, they are creating environments that complete human nature—environments, in fact, that embody the very activity of reason that legislators themselves deploy in making law (chap. 2).

This raises new questions. If law is compatible with political naturalism, why does Aristotle portray law as being relative to different types of political regime? The answer (chap. 3) is that, when making laws as best they can as natural political animals, legislators necessarily draw on their conception of the human good. However, as members of the ruling class, they hold the same conception that gives the regime its form. Cities ruled by the rich thus produce oligarchic laws; cities ruled by the poor yield democratic laws; the best of all regimes—ruled by excellent people who most deserve to rule—yields the best laws. Law is always “partisan” in that it reflects the view of the part of the city that rules.

That said, there is a key difference between rulers who draw on flawed views of the good that primarily serve to further the interests of the ruling clique, and virtuous rulers whose distinctive view is that law should serve the common good. Chapter 4 explores the nature of the common good. On one hand, individuals enter into city life to secure their own good. So, in one sense, the common good is the aggregation of all these individual goods, along with the civic conditions that are instrumental for promoting it. Duke calls this common good a “motivational reason” since it refers to the (aggregate) motives of all the individuals who choose city life. Duke argues, however, that Aristotle also posits goods that exist at the level of the civic whole. Like a ship that cannot be hauled at all by one person alone, some civic conditions (like communal friendship) take place only at the level of the collective and so act as “normative reasons” that give actions value from a source beyond any specific individual.

With this common good clarified, chapter 5 explores how it functions as a goal for legislators who find themselves in nonideal situations. As is widely recognized, Aristotle does not simply announce that legislators should do whatever they can to reform their city to match the ideal scenario. Indeed, when it comes to political transformation, Aristotle is far more cautious. This is not because stability acts as an independent goal, sometimes coming into conflict with the separate goal of making progress toward a common good. Rather, the explanation is that Aristotelian legislators consider actions and laws in terms of what sociological realities allow. Political action is not a function of will or rhetoric, but usually involves movement by the hubristic rich and envious poor—two highly unstable groups who, with little provocation, may initiate stasis. Aristotle's emphasis on the continuity of habits and his ranking of defective regimes based on how law-abiding they are, as well as other ways in which he focuses on preservation, can be traced to his sober reflections on the sociological matter out of which cities are formed.

The final two chapters, in a sense, take us beyond Aristotle's thoughts on law and attempt to put his views in context. In chapter 6, Duke explores how Aristotle's views on law relate to natural law theory. Although there are many versions, the core claim of any natural law theory is that the existence and content of positive law depends, in some way and to some extent, on some extrapositive normative foundation. Duke argues that Aristotle's views on justice and law do not fit well with the Thomistic version that favors a divine foundation, and they have a rather strained relation to the Stoic view that what accords with nature is a foundation. By contrast, Duke finds several ways in which Aristotelian positive law draws upon reason as a normative foundation because what is lawful, in a focal sense, has a normative orientation toward the common good as grasped by a rational legislator. Chapter 7 closes the book by showing how Aristotle's conception of equity (and the ability of excellent agents to handle particular situations well) does not undermine the value of law by injecting arbitrariness and “decisionism” into its foundation. While appeals to equity and the particular insights of exemplary agents highlight the shortcomings of the universality in law, they do not undermine the rule of law since Aristotelian equity is exercised by someone drawing on legislative science, wisdom, and experience rather than any contingent psychological preference.

Let me close with a friendly criticism of this otherwise excellent book. While Duke has done an admirable job recovering Aristotle's notion of law, I do wish he had said more about its significance and legacy. This is a monograph that rescues Aristotle from many positions: he is rescued from intellectualism, holism, natural law (of a sort), decisionism, and so on. But for what does Duke believe we are saving Aristotle? To what precisely does recovered Aristotelian law contribute? I often found myself reminded of political philosophies that resist easy assimilation to the social contract tradition. But it is not clear whether Duke would agree.