When John Rawls died in 2002 he was, without doubt, the most significant political philosopher in the English-speaking world. This may come as a surprise to some readers because Rawls’s name is almost entirely unknown outside academic circles. His major works — “A Theory of Justice” (1971), “Political Liberalism” (1993), and “The Law of Peoples” (2001) — are large and forbidding books that remain principally within the purview of professional philosophers. Still Rawls’s influence has been massive.

Rawls’s ambition was to re-establish the grand tradition of political philosophy at a time when it was widely considered moribund. It had become either something called “the history of political thought” which examined political ideas in their historical context, or a branch of “analytical philosophy” which was based on the minute linguistic and logical analysis of concepts. The publication of “A Theory of Justice” had the virtue of breathing new life into a dying field. Rawls turned back to the social contract tradition of Thomas Hobbes, John Locke, and especially Immanuel Kant in order to derive substantive principles of justice that could provide a defense of a more democratic social order.

Rawls’s project has been enormously influential not only in departments of philosophy, but also in political science, economics, and especially law. Although widely criticized in many of its particulars, his work set the field of political philosophy on a whole new course. His Harvard colleague and critic, Robert Nozick, once wrote ,”Political philosophers must now either work within Rawls’s theory or explain why not.” This is no doubt an overstatement, but it indicates something about the hegemony that Rawls’s theory has exercised during the past 30 years.

Such a project was bound to invite critics. Some found Rawls to be arguing that the only legitimate society is one actively engaged in the redress of inequalities. Others believed that his particular theory of distributive justice would end by empowering courts and judges — a new class of philosopher-kings — at the expense of the give-and-take of everyday legislative politics. And still others, the so-called communitarians, found his assumptions about human nature and rationality too thin to account for the affective and constitutive bonds of political community.

Rawls’s posthumously published “Lectures on the History of Political Philosophy” (Harvard University Press, 457 pages, $35) are based on lecture materials given at Harvard in the 1970s and ’80s. In these essays that have been reconstructed from computer files, handwritten notes, and recording tapes, Rawls engages with the giants of modern political philosophy — Hobbes, Locke, David Hume, Jean-Jacques Rousseau, Karl Marx, and John Stuart Mill. While many contemporary philosophers have deliberately shunned the history of political philosophy as irrelevant to “doing” philosophy, Rawls shows himself to be a conscientious and painstaking reader of the great works of the philosophical tradition of which he was a part. He regarded his own work as both indebted to and as culminating the great tradition that he interprets for his readers.

Rawls typically wrote in a gray bureaucratic prose — the style only a lawyer could love. Nevertheless the Editor’s Foreward to the book contains a semi-autobiographical fragment from a 1993 essay titled “Some Remarks About My Teaching” in which he stresses two features of his pedagogy. The first was to try understand the great thinkers as they understood themselves, not to impose our contemporary preconceptions and concerns on them but “to pose their philosophical problems as they saw them, given what their understanding of the state of moral and political philosophy then was.”

The second feature was always to make the strongest possible case for the figures he was reading. A sign of his generosity as a reader was a favorite adage of his quoted from John Stuart Mill: “A doctrine is not judged at all until it is judged in its best form.” To achieve this end, he writes, “I always assumed that the writers we were studying were always much smarter than I was. If they were not, why was I wasting my time and the student’s time by studying them?” One learns how to do moral and political philosophy by studying its greatest “exemplars” and not contemporary figures who are likely to be derivative and second-rate.

The strength of Rawls’s “Lectures” is in his analysis of the social contract tradition of which his own writings form a part. It is disappointing, therefore, that the “Lectures” do not contain an explicit treatment of the Kantian version of the social contract given that Rawls has done more than any single individual to restore the prestige of Kant as a moral and political philosopher. The Kantian approach to rights, autonomy, and human dignity all take pride of place in Rawls’s pantheon of values. In order to discover his considered judgment on Kant one has to turn to this work’s companion volume, Rawls’s “Lectures on the History of Moral Philosophy” (2000).

Despite his best efforts to teach the great political philosophers in their own terms, Rawls’s readings often view their texts through the lenses of his own moral preoccupations. He seems to impose a progressive account of the history of philosophy culminating in his own egalitarian conception of justice as fairness.

The problem with Rawls’s readings is less with what he says than in what he omits. This is especially true of his treatment of religion. Modern political philosophy grew out of the crucible of the wars of religion of the 16th and 17th centuries. Yet while Rawls acknowledges this origin, it plays virtually no role in how he understands early modern thinkers such as Hobbes, Locke, or Rousseau. Rawls’s emphasis on the “rational” or “reasonable” society displays a consistent tone-deafness to the theological debates from which early modernity arose.

What Rawls calls “political liberalism” is his attempt to establish criteria of public discourse that are internal to reason alone and therefore exclude controversial theological or philosophical worldviews. The result of this procedure is to create an entirely secularized vision of society in which a purified doctrine of public reason is deemed the only legitimate arbiter of political debate. Rawls then reads this procedure back into the founders of modern thought, none of whom ever believed that politics could dispense with religion as a crucial component of political rule.

Perhaps the least satisfying aspect of Rawls’s book is the conception of philosophy that he presupposes. “Political philosophy,” he writes, “has a not insignificant role as part of the general background culture in providing a source of essential political principles and ideals.” Leaving aside the ambiguity contained in the phrase “not insignificant,” this hardly begins to describe the conception of philosophy held by most of the thinkers within the great tradition. Rawls’s idea that philosophy forms part of a “background culture” is like saying its goal is hanging the wallpaper in Plato’s cave. None of the thinkers who Rawls surveys (with the possible exception of Hume) ever thought of philosophy in these terms. They were all “untimely” philosophers in Nietzsche’s sense of the term, setting out not to rationalize but to challenge the dogmas and preconceptions of their age.

Rawls’s work, for better or worse, is not inspired by this kind of epic ambition. His very modesty and lack of speculative curiosity are what exclude him from the ranks of the great philosophers. Rawls is not an Isaiah Berlin with his anguished sense of the conflict of goods which besets human life; nor is he a Leo Strauss with his vivid awareness of the forces of persecution with which philosophy has always to contend; nor is he a Michael Oakeshott with his diagnosis of the dangers posed by excessive rationalism to the goals of a free society. Rawls is a philosopher for our time. His desire is to render both theoretically and practically legitimate the redistributivist policies of the prosperous North Atlantic welfare states. There is already more than a whiff of nostalgia about this project. This is by no means a contemptible goal, but it is well to remember that this project of rationalization is one — but only one — way in which philosophy can be practiced.

Mr. Smith, the Alfred Cowles professor of political science at Yale University, last wrote for these pages on Leo Strauss.