Philosophy, Rawls maintains, contributes in several ways to the task of self efinition, which forms an essential part of modern democracy. It shows us, most directly, how the principles of democratic life may be elaborated so as to handle the political and social conflicts that sometimes threaten to tear us apart. But it also has the more basic function of orienting us in our political world, distinguishing the things that ought to matter to us as citizens from the other sorts of concerns we pursue in our lives. Since it focuses on underlying principles, it can even (within measure) calm the rage we may feel at current policies and reconcile us to our society in the light of its more enduring values. Finally, philosophy challenges the status quo by imagining new institutional arrangements that might better honor our democratic ideals. At its best, Rawls likes to say, it is "realistically utopian."

Clearly, political philosophy can only play these various roles if it shares in the very developments that have brought about the modern democratic age. In general, Rawls believes, political theory always draws upon the materials available in its historical situation, even when it calls for revolutionary change, and even when it arrives at principles of justice by imagining what rules of association rational agents would adopt in "a state of nature," prior to the formation of society. Philosophers may talk as though they were dealing with the unchanging problems of political life--the essence of a legitimate regime, the grounds of political obligation--and as though their reasoning unfolded from some Archimedean point removed from the bounds of time and place. Yet this self-understanding is mistaken. Even if there are some enduring questions, the manner in which they are understood as well as the kinds of argument used to address them are always colored by tradition, experience, and the realities of the day.

Rawls quotes approvingly R.G. Collingwood's observation that "the history of political theory is not the history of different answers to one and the same question, but the history of a problem more or less constantly changing, whose solution was changing with it." Collingwood himself believed that all philosophy, even metaphysics, has an inescapably historical character. Rawls never advanced so global a claim. In these lectures as in his other writings, he always keeps his sights fixed on the domain of moral and political philosophy. But most significantly, Rawls did not let a sense of history turn him into a sidelines commentator, content to point out the presuppositions shaping other philosophers' thinking. He threw himself into the fray and constructed his own full-scale theory of social justice, one that rivals the masterpieces of the past.

Rawls thus managed to combine two convictions that generally, if wrongly, appear at odds with one another. He believed in the power of systematic theory, and at the same time he recognized its historical rootedness. Few works of political philosophy have been so intricately and painstakingly argued as A Theory of Justice. Yet its famous conception of justice as fairness, he declared, "draw[s] solely upon basic intuitive ideas that are embedded in the political institutions of a democratic society and the public traditions of their interpretation." Rawls saw no inevitable tension between his love of theory and his historical sensibility. Principles and arguments clarify where we stand and show how to handle the problems we encounter; remembering how we have become who we are keeps us alert to the hard-won lessons we need to carry into the future. It is therefore not surprising that his Lectures on the History of Political Philosophy show us a Rawls keenly aware of the historical underpinnings of his own theoretical constructions.