There are three main ways of reading Hobbes's political writings: as political philosophy, written for the ages; as political commentary, tackling the controversies of the time; and as political advice, offering practical suggestions to current or future sovereigns. Unusually, Perez Zagorin's high-quality book tackles all three.

Hobbes's political philosophy is the main focus. Zagorin, a historian of early modern political thought, clearly and concisely compares Hobbes's natural law theory with that of his predecessors (pp. 5–28, 32–38, 46–50). This highlights Hobbes's originality very effectively. In particular, Zagorin insists that Hobbes does not follow Grotius as much as some scholars have argued (pp. 18–20, 24–26, 139–40, 146). He is less convincing in rejecting the view that Hobbes's natural law theory is based purely on self-interest and is not therefore a moral theory (pp. 47–48, 100–11, 145). He is right that Hobbes's theory includes “a large body of moral values and virtues,” including peacefulness and benevolence, which “would have to be part of any true system of morality, irrespective of its underlying philosophic perspectives” (p. 48). But these are compatible with self-interest, as Zagorin himself accepts (pp. 102–3). So, more is needed to show that Hobbes offers not only “a system of morality” but also “a moral theory” (pp. 47–48).

Hobbes's political commentary, engaging in the controversies of his time, gets less emphasis from Zagorin. One important but frustrating contribution is his challenge to Quentin Skinner, who has argued that Hobbes changed his account of liberty partly to oppose republican ideas (Hobbes and Republican Liberty, 2008, pp. 140–77). “Before the 1650s there was no body of political thought in England that could be identified as republican,” counters Zagorin (p. 77). But Skinner's interpretation does not require a republican “body of political thought,” merely the existence of prominent writers advocating republican conceptions of liberty, a quite different claim—and one that Skinner supports with ample evidence. Zagorin also objects to Skinner's position by stating that Hobbes's theory of liberty was framed “not as an answer to the republican theory but as a development of his civil science” (p. 78). This is questionable on three counts: It is mere assertion, needing further detail; it is a false dichotomy, since the two positions are compatible; and it misrepresents Skinner, who avoids the false dichotomy by arguing that Hobbes's theory of liberty was both an answer to republican theory and a development of his civil science. Skinner is also criticized rather sketchily in a tantalizing footnote where Zagorin simply announces, without further comment, that “Skinner … is mistaken, I think, in stating … that Hobbes was not an exponent of a pure negative theory of liberty” (p. 154).

Hobbes's political advice is usually neglected, even though each of his main political works has a chapter giving counsel to sovereigns (Elements of Law, Chapter 28; De Cive, Chapter 13; Leviathan, Chapter 30). Yet most interpretations of Hobbes are overly philosophical. Many scholars see the state of nature as hypothetical, and believe that a fundamental problem for Hobbes is whether we really could get out of the state of nature. But Hobbes also saw the state of nature as something real; there was a state of nature during the civil war, for example. An equally fundamental problem for him is thus how to avoid going back to a state of nature. Mainstream scholars who discuss Hobbes's practical advice usually overemphasize the importance of fear. Yet Hobbes also says a great deal about education—“the key to the maintenance of social order” (Sharon Lloyd, Ideals as Interests in Hobbes's Leviathan: The Power of Mind over Matter, 1992, p. 219). For example, civil disorder arises partly through faulty opinions “which are gotten by education,” but faulty opinions can still be “taken away … by time and education” (The Elements of Law, Chapter 28, section 8). Reading republican texts like those of Aristotle and Cicero is like “the biting of a mad Dogge” producing rabies (Leviathan, Chapter 29), but teaching “absolute obedience to the laws of the King” should bring “lasting peace” (Behemoth, Part 1).

Zagorin does not initially get the right emphasis here, depicting the state of nature “largely as a hypothetical condition” (pp. 39, 45), and stressing how Hobbes sought to supplement the law of nature with fear (pp. 55–56, 62). Only briefly does Zagorin mention education as a tool for averting disorder (pp. 32, 81, 104). Nonetheless, he makes an extremely important statement in writing that Hobbes's work “belongs in certain respects to the broad genre of European literature of … advice to princes” (pp. 84–85). And he is entirely right to emphasize equity, a very significant norm for Hobbes (pp. 92–95) and one underplayed by most commentators. Equity is a law of nature that requires “the equall distribution to each man, of that which in reason belongeth to him” (Leviathan, Chapter 15). Zagorin sees equity as “the fullest expression of equality and fairness in the treatment of human beings … and the highest standard of moral reason and rectitude, from which neither the sovereign nor the civil law can be excepted” (p. 94). He accurately captures Hobbes's repeated emphasis on the high standards required by good sovereigns, and does this neatly with a subsection entitled “Hobbes's Very Moral Sovereign” (p. 84), perhaps the most important idea in the book.

Of course, equity is only a moral standard for the sovereign, who remains unbound by practical checks like civil rights or mixed government. Zagorin is right to emphasize “a broad strain of humanity and liberalism” in Hobbes's arguments on religious toleration (pp. 119–28), but Hobbes remains an absolutist: From a contemporary perspective, it is “a serious deficiency in his moral and political theory” that he does not supplement the sovereign's moral standards with a fuller set of rights for subjects (p. 128).

Overall, this short and clear book is a valuable contribution to the literature. The first two chapters advance our understanding of Hobbes's ideas on natural law; Chapter 3 has a noteworthy account of the moral constraints on sovereigns; and the final chapter's defense of Hobbes's humane theory is neatly encapsulated by the clever pun in the title “Hobbes, The Moral Philosopher” (p. 99).

Hobbes and the Law of Nature was Zagorin's last book; he died three months before it was published.