Everyone says that after the horror, the people were beautiful. Shopkeepers bringing carts of food to workers at the World Trade Center. Young black men helping old Jewish men cross the street. Construction workers driving from Missouri to Manhattan with a truck full of equipment, just to see what they could do.

Even in Washington, you could tell. September 11 began as one of those amazingly clear and bright days that mark a change of season. By the end of the day, the smallest human exchanges were different, as if a miasma of self-involvement and indifference had been ended by a thunderstorm. We hugged people whose hands we usually shake. People who asked "How are you?" really wanted to know -- and would stand still for a rambling, sometimes tearful answer. I heard myself use a new tone of voice when I thanked a clerk for change, or said goodnight to the desk attendant in my apartment building. For a week, every e-mail began with expressions of hope that the reader had not been more closely touched by the disaster than the rest of the country.

No national event in [our] lifetime had done this: changed the way people say goodnight to each other. We who don't remember a war have mostly lived our lives with our selves front and center. It has been a great time for the cultivation of the self -- preening, self-admiration, self-criticism, self-improvement, self-sculpting, self-loathing, and eventually boredom with one's own incessant company. After that Tuesday, for the first time, a shared condition came before our private pleasures and discontents. Amidst all the horror and sadness and shock, there was a small sense of relief that we could still feel this way, that solidarity was not a casualty of two decades of wealth and comfort.

Before the attacks, two strains of American culture were developing very different responses to our long and tedious liaison with self-concern. The ironic manner -- impenetrably diffident, preemptively but languorously dismissive, and quietly determined to make a joke of anything before someone else did -- had become a default mode among young sophisticates. It rested on a perception that nothing in the world was interesting, dangerous, urgent, or lovely enough to take a chance on, and insulated itself against seduction with irony. Although it could look like nihilism, the ironic manner was actually closer to hibernation: a retreat when the landscape provided little sustenance for passion or conviction. Tracked to its den, even the most ironic bear usually had some quiet affection to share, and appetite stored up for the spring.

The other strain took the form an appetite for experiences that carried people beyond their spoiled and somewhat uninteresting selves. In broad strokes, there were three expressions of this appetite. The most visible was the revival of interest in World War Two. This was mostly a boomer phenomenon, and its charms included an implicit rebuke of a generation whose wartime experience was much more ambivalent and embittering -- and, in the majority of cases, much more self-concerned. The attraction of the World War Two generation was precisely that it seemed to set aside self-concern for the belief that the country's war effort was larger and more urgent than any one life.

People under thirty-five or forty got out of themselves in a different way. The refined savagery of Fight Club was the touchstone for an impulse that extended to extreme sports, high-altitude mountaineering, and all the other testing of physical limits that came into fashion among the young and robust. If the world cannot draw us out of ourselves, the thought went, we will expunge our lassitude by sheer will and force. Because there is no struggle that calls us to put ourselves on the line, we will have our wars against each other, just to get the rush of danger and pain. And we will, as the cliche has it, battle the elements and the limits of our own bodies on ice fields and in class VI whitewater. Action, urgency, and necessity don't come unbidden to every generation, but ours has been particularly resourceful in manufacturing them.

The other, predictable self-straitening device for younger people was radical politics, which hit a higher level than at any time since the sixties. Ever since the modern idea of revolution turned France upside down, the sentiment of solidarity and the idea justice have been a tonic for lassitude. Protestors against the International Monetary Fund, the World Bank, and the World Trade Organization made a bid to define a generation at Seattle in 1999, and following the summer's events in Genoa they were set to make or break their movement in the now-canceled fall meeting of the World Bank and the IMF in Washington. They had matured a lot in two years, but in a sense they were still playing at politics: they had not yet found a way to define a reform program for global capitalism, and that lack often left them protesting for the sake of dissent, much as the Fight Club warriors fought for the sake of violence.

Now there is no more need for make-believe. There may not even be space for it. The political drama beginning to unfold already makes the earlier globalization fights seem a peacetime indulgence as thin and easily wrecked as the protestors' papier-mache puppets. It we want to see a generation of troops mobilized, CNN's footage is as sharp as Spielberg's. As for Fight Club , we have had enough violence in one morning to remind for a lifetime that it is horrible. We are promised more. Several critics have suggested that irony's ascendancy is over, and for the moment they are clearly right. Acting as if nothing could concern us or catch our attention now would not just be obtuse; it would be indecent.

In some quarters, the main cultural product of our times is instant analysis, the informed opinion delivered on any topic with five minutes' notice. That is usually fatuous, but now it is dangerous. The season has changed, the landscape has shifted, and there is no such thing as instant comprehension of a new setting. All anyone can do, really, is to let the outrage and horror of September 11, the wonder at the upwelling generosity that followed it, and the scared excitement of what follows pass through him and become part a new metabolism. Gandhi used to fast and meditate before concluding what some new event might mean -- in a sense, washing out the old perceptions and presuppositions, to see what would replace them. Anyone who wants to make sense of the culture now needs to do something similar.

All of this is necessary because, in the end, introspection is our main device for understanding the world. We put things in order by setting them against our internal logic or illogic. Now we who know nothing, really, about war, are learning our first lesson: war changes everything, starting with us. It is possible that we will not know how have been changed until we come to rest again.