In the midst of a heated political discussion, you may still hear it said that ideas don't matter. Ideas are mere veils, we say: gauze draped over the harder stuff of interests and prejudice. But in fact, ideas matter tremendously. They frame events into patterns. They shape policies and politics. They fuel ideologies and social movements of every sort. They help to set limits on the very possibilities of what can be imagined for one's self and society. Let the frames of common sense shift, and everything is disrupted. Age of Fracture is the story of an era in U.S. history when ideas of all sorts cracked and, in their fracture, remade the frames of common sense. Between the mid 1970s and the end of the century, many of the assumptions that had dominated mid-twentieth century American public life were transformed. Keynesian ideas of macroeconomics, put through the wringer of the economic crises of the 1970s, began to be challenged by models of perfect markets, where the decisions of individual consumers and shareholders kept economies in equilibrium better than the conscious work of macroeconomic managers. Notions of identity grew more individual and fluid. Visions of solidarity of all sorts-class solidarity, racial nationalism, sisterhood-splintered. Strong ideas of society and social relations that had been nurtured in the Cold War disaggregated into smaller, micro bits. Where the power of the macro-forces of history, institutions, and society had absorbed the imagination of mid-twentieth century intellectuals, public language now ran hard toward emphasis on choice and individual agency. Some of the era's disaggregation of social thought into micro-pieces was the work of the new conservative and libertarian think tanks. "It's a war of ideas," they declared, and they fought it with skill and intensity. But the reshaping of ideas and assumptions went on across the board, through varied routes and different crises: on the political/cultural left as well as the right, in the universities as well as in the partisan idea factories and in the best-seller lists. In tracing these debates I have tried to draw the canvas of Age of Fracture broadly. It deals with the era's knotty intellectuals: John Rawls, Judith Butler, Michel Foucault, and others. It deals with the era's popularizers and simplifiers of big ideas like Alvin Toffler, Milton Friedman, and Francis Fukuyama. It follows the ways in which the era's fractures in ideas spilled into public policy debates over affirmative action and racial justice, "shock therapy" for post-Communist economies, original intention in Constitutional law, economic deregulation, multiculturalism in the schools, and the language of presidential politics. Along the ragged terrain where big books and public controversies collided, the nation's conversation with itself was remade. The age of fracture is still with us. Its ideas, aspirations, and neoliberal policy innovations circle the globe. At home in America, the splintering of the social imagination dominates public life. The polarized arguments that now gridlock U.S. politics, the libertarian fantasies in the early primary air, the weakness of strong words for social bonds and obligations, even in the midst of collective economic crisis-all this is a consequence of shifts in the last quarter century's intellectual terrain. And so are the far more open, freer notions of individual possibilities, born in the same heated arguments. Age of Fracture is a history, not a venture in nostalgia. It was written in the hope that by retracing the steps by which one set of intellectual assumptions gave way to another, we might find our way to something more adequate for our times, when our practical, collective interdependence strains against the choice-saturated language with which we try to grasp it. "I live in a different country than the one into which I was born in 1942." Alan Wolfe wrote in The Book, the New Republic's online review. "I have never been quite able to pinpoint exactly what makes it so different. More than any other book I've read in recent years, Age of Fracture, by the Princeton historian Daniel T. Rodgers, has helped me to discover and to understand that difference." I, too, was born in 1942, as it turns out. But I have tried to write a book, not for a generation, but for all those who want to try to understand that powerful, idea- and argument-filled enigma that is contemporary America.