In the six chapters and three appendices of The Long Arc of Legality David Dyzenhaus proposes a legal theory in which, together with the officials of law, the legal subject, the individual human being, provides an internal point of view about the validity of law. Thus, beyond the Hartian project of a positivist law—law devised according to the legal system and applied by a judge practicing the virtues of the profession—the novelty that Dyzenhaus contributes to the debate in the philosophy of law is “bringing the legal subject into the picture” (68).

The introduction is probably the closest that a legal theory book can come to a thriller—the book starts terrifically. Dyzenhaus introduces a key method for analyzing his thesis. It revolves around the predicament of judge and subject alike when confronted with a “very unjust law,” for instance a law that would expand apartheid principles. Because of the inherent characteristics of law, the judge is morally bound to apply the evil law, no matter what. However, for the same reasons, she or he is morally bound not to apply that unjust law. Whatever Ronald Dworkin believed, this is far from a case for the laboratory, but constitutes a very real moral dilemma for which “a concept of law is needed which does not suppose either that law can have any content whatsoever, or that when a particular law appears to have a very unjust content, the situation is morally but not legally problematic” (58). The author's main argument is that this concept must be a legal theory and not merely a moral theory. In comparison to many twentieth- and twenty-first-century philosophers of law, Dyzenhaus views his project as one really taking law (and not merely “the law”) seriously. Moreover, the problem of the evil law is, according to the author, the same for natural lawyers and legal positivists. If philosophy of law does not tackle it, it simply renounces its purpose precisely as philosophy of law. Dyzenhaus devotes chapters 1 and 2 to studying the responses to the puzzlement of the very unjust law given by Ronald Dworkin, H. L. A. Hart—to whom arguably the book aims to respond more generally—Joseph Raz, and Thomas Hobbes. The book also pays attention to the legalism of Gustav Radbruch and Hans Kelsen, and to Hermann Heller, Oliver Wendell Holmes, Lon L. Fuller, and several others.

The elegantly nuanced discussion of chapter 1, impossible even to broach in this short space, shows that the main legal theorists of the twentieth century were not able to overcome the problem of the very unjust law. For Hart, to state that the unjust law is not law sounded like a natural law “exaggeration” if not “a falsity” (47). However, in his view a judge ought to pause and state that this is a valid law, “but too evil to be obeyed” (50). But if such law is to remain law, it cannot have any content. Hart's inherent ambiguity, in defending the separation thesis and at the same time a minimal natural law content in law, resulted in failure to explain from a legal point of view why that is so.

Chapters 2 and 3 turn to Hobbes's social contract theory and start thus to delineate the arc of legality referred to in the title of the book. The benefit of studying Hobbes lies for Dyzenhaus in seeing how the sovereign is legally constituted. Despite the orthodox view of Hobbes as having argued that there can be no formal legal limits on sovereign authority, the author thinks that at least its lawmaking is subject to the equivalent of a Hartian rule of recognition—an equivalence that appears a bit stretched, and not by any fault of Hobbes. Hobbes's “good judges” (108) and the interpretation of law in their judgment in the light of natural law principles are “an integral part of the exercise of sovereignty” (114). This activity “makes the moral substance implicit in law explicit” (116). After many years of studying Hobbes, this reviewer fully subscribes to Dyzenhaus's reading of the philosopher of Malmesbury—and hence to the book's argument more generally. Hobbes's seventeenth-century humanism radiates through his natural laws: peace, equality, care for the individual's necessities and convenience, and (with certain caveats) liberty. Natural laws also illuminate the artificial constitution and the legal order founded on them.

With this Hobbesian background, Dyzenhaus's focal point is the individual subject, who, by having consented to the constitution of the legal order, abides by it even though it might conflict with her or his personal morality. Theoretical examples are “Hobbes's Just Men” and “Kelsen's legal man,” or perhaps, “Raz's Kelsen's legal man.” When “legal subjects accept that the modern legal order is legitimate even when some of its norms do not correspond with their sense of justice, and so they should regard particular laws as binding on them, even when they do not endorse the content of the rules,” then “this is a kind of moral relativism” (172). Individuals consent to that situation because of an appreciation of its democratic origin and its legal legitimacy in “transforming might into right.”

Importantly, legal officials ought to maintain and nurture the foundational domain of the authority of law in a manner that the legal order continues to make sense for the legal subject. Formally and substantially the answer to the latter's question “But how can that be law for me?” must be continuously satisfactory. Otherwise, the legal order might be collapsing in front of our eyes; or perhaps it was never a legitimate legal order. Since Dyzenhaus also considers “jural communities” in international law terms (265), the question posed by the legal subject to the judge opens valuable critical possibilities in that field.

Dyzenhaus argues that when the sources of the authority of law are sought within law, as is the case for legal constitutionalists, that is, in the “fundamental, substantive, public commitment” with the legal order (216) and the moral and political principles that glued laws into a unified legal order, they help solve the puzzle of the “very unjust law.” For the principles underlying the legal order “condition” the content of law (354). They endow the legal order with a characteristic moral legality, a term that Dyzenhaus does not use, but that seems to me to express well his meaning. Despite his obvious admiration for the Austrian legal theorist, Kelsen's theory must in his view become more political if it, too, is to sustain the arc of legality (418).

The greatest interest of this discussion, almost a paradox, is that The Arc of Legality confronts us with the core of our humanity: Why do communities come together in the first place? How does law help in that endeavor and why might neglect or open attack on the legal order destroy those things that make life worth living? The book is most ambitious in its daring and powerful analysis of Hart, the overarching goal of breaking the impasse between natural law and positivist theories, and the depth of its argument. Has Dyzenhaus managed to unite the struggles for law of legal positivists and natural lawyers? Perhaps the right answer to that question is that at the very least he has removed some empty armor that prevented our seeing the principles for which we all fight.