The twentieth century is hardly behind us but already its quarrels and its achievements, its ideals and its fears are slipping into the obscurity of mis-memory. In the West we have made haste to dispense whenever possible with the economic, intellectual, and institutional baggage of the twentieth century and encouraged others to do likewise. In the wake of 1989, with boundless confidence and insufficient reflection, we put the twentieth century behind us and strode boldly into its successor swaddled in self-serving half-truths: the triumph of the West, the end of History, the unipolar American moment, the ineluctable march of globalization and the free market.

The belief that that was then and this is now embraced much more than just the defunct dogmas andinstitutions of cold war–era communism. During the Nineties, and again in the wake of September 11, 2001, I was struck more than once by a perverse contemporary insistence on not understanding the context of our present dilemmas, at home and abroad; on not listening with greater care to some of the wiser heads of earlier decades; on seeking actively to forget rather than remember, to deny continuity and proclaim novelty on every possible occasion. We have become stridently insistent that the past has little of interest to teach us. Ours, we assert, is a new world; its risks and opportunities are without precedent.

Perhaps this is not surprising. The recent past is the hardest to know and understand. Moreover, the world really has undergone a remarkable transformation since 1989 and such transformations are always unsettling for those who remember how things were before. In the decades following the French Revolution, the douceur de vivre of the vanished ancien régime was much regretted by older commentators. A century later, evocations and memoirs of pre–Word War I Europe typically depicted (and still depict) a lost civilization, a world whose illusions had quite literally been blown apart: “Never such innocence again.”1

But there is a difference. Contemporaries might have regretted the world before the French Revolution. But they had not forgotten it. For much of the nineteenth century Europeans remained obsessed with the causes and meaning of the upheavals that began in 1789. The political and philosophical debates of the Enlightenment had not been consumed in the fires of revolution. On the contrary, the Revolution and its consequences were widely attributed to that same Enlightenment which thus emerged—for friend and foe alike—as the acknowledged source of the political dogmas and social programs of the century that followed.

In a similar vein, while everyone after 1918 agreed that things would never be the same again, the particular shape that a postwar world should take was everywhere conceived and contested in the long shadow of nineteenth-century experience and thought. Neoclassical economics, liberalism, Marxism (and its Communist stepchild), “revolution,” the bourgeoisie and the proletariat, imperialism, and “industrialism”—the building blocks of the twentieth-century political world—were all nineteenth-century artifacts. Even those who, along with Virginia Woolf, believed that “on or about December 1910, human character…