We are a nation of ambitious people, and yet ambition is a quality that is hard to praise and easy to deplore. It's a great engine of American creativity, but it also can be an unrelenting oppressor, which robs us of time and peace of mind. Especially in highly prosperous periods -- periods like the present -- it becomes fashionable to question whether ambition has gotten out of hand and is driving us to excesses of striving and craving that are self-destructive.

Ambition is not, of course, only a quest for riches. The impulse pervades every walk of life. Here is Al Gore straining to be president -- campaigning earnestly without any apparent joy -- to fulfill an ambition that must date to his diaper days. And does anyone really believe that the fierce rivalry among America's immensely rich computer moguls (from Microsoft's Bill Gates to America Online's Stephen Case) is about money? What it concerns is the larger ambition, harbored by all, to control the nation's cyberagenda.

One-upmanship is a national mania. You see it every time a wide receiver prances into the end zone and raises his index finger in a triumphant "We're No. 1" salute, even if his team is mired in a losing season. More common is the search for status symbols -- a bigger house, a more exotic vacation, a niftier bike, a faster computer -- that separate us from the crowd. Money may not be the only way to satisfy this urge, but it's the most common because it can so easily translate itself into some other badge of identity and standing.

For many people, the contest seems futile. The New York Times recently ran a long story on four families with roughly $50,000 of income who "wonder why they have to struggle so hard just to pay the bills." The answer isn't that their incomes are stagnating. Between 1992 and 1997, the median income of married couples rose from $48,008 to $51,681 in inflation-adjusted dollars, reports the Census Bureau. They are surely higher now. All the families profiled by the Times owned homes. Their recent purchases included "double-door refrigerators, radiant-heat stoves . . . big-screen TVs . . . computers and elaborate outdoor grills."

The problem isn't that they're running in place but that they're running in the pack with everyone else. Consumer products morph from luxury to convenience to necessity. Cars, TVs and microwaves all followed the cycle; now it describes Internet connections and cell phones. If you don't buy by the final stage, you're considered a crank or a pauper. There's nothing new here. In "The Theory of the Leisure Class" (1899), Thorstein Veblen argued that once an item becomes widely owned, possessing it becomes a requisite for "self-respect." People try to consume "just beyond [their] reach" so they "can outdo" those with whom they compare themselves.

Frustration is preordained. Despite the booming economy, a Newsweek poll in June reported that 29 percent of adults found it "more difficult" to "live the kind of life" they want, while only 23 percent found it less difficult. (For 47 percent, there was no change.) The stress can lead to tragedy. Perhaps this is the story of Mark Barton, the day-trader who murdered 12 people. People routinely try to beat the system through get-rich-quick schemes. This partly explains the explosion in legalized gambling. In 1998 Americans lost about $50 billion gambling. About 125 million people gamble, and 7.5 million are "problem," or "pathological," gamblers, reports the National Gambling Impact Study Commission.

We're constantly advised to subdue ambition. Search for deeper meaning in family, friends and faith, we're told. Money cannot buy happiness. This seems sensible -- up to a point. The General Social Survey at the University of Chicago asks people to rate their happiness. The 1998 survey shows a somewhat stronger relation between money and happiness than earlier polls. About 34 percent of those with incomes between $30,000 and $50,000 were "very happy" and 58 percent were "pretty happy." Above $110,000, the ratings were 51 percent "very happy" and 45 percent "pretty happy." (Marriage has a bigger impact than income; the "very happy" rate of couples is about double that of singles.)

In a recent book ("Luxury Fever"), Cornell University economist Robert Frank urges that we penalize overambition with a progressive consumption tax. The more people spend, the higher their tax rate. Spend $5,000 on a watch instead of $50, and your taxes go up; buy a car for $60,000 instead of $20,000, and pay more taxes. People wouldn't be worse off, Frank argues, because they'd be shielded from the "arms race" pattern of competitive consumption. Indeed, they'd have more free time, because it wouldn't pay to work so hard.

Hmm. Let's rethink. Though unlovable, ambition is socially useful. It sustains economic vitality. It prods people to take risks and exert themselves. The Internet is the offspring of workaholics spending eight-day weeks to invent a new world and make a fortune. When the process works well, gains overwhelm losses -- and not just in economic output. Today's hyperprosperity has improved the social climate. Almost all indicators of confidence have increased.

What people disdain as ambition they also venerate as opportunity. As Alexis de Tocqueville long ago noted, America was built on the notion that -- unlike Europe, with its hereditary aristocracy -- people could write their own life stories. The ideal endures. A 1996 survey asked whether anyone starting poor could become rich; 78 percent of Americans thought so. But it's not just the economy or even politics. Social standing is fluid everywhere. Ambition and its creative powers permeate the arts, the professions, academia, science. Because everyone can be someone, the competition to rise above the crowd is unrelenting and often ruthless.

Few of us escape ambition's wounds. There are damaged dreams, abandoned projects and missed promotions. Most of us face the pressures of balancing competing demands between our inner selves and outer lives. A society that peddles so many extravagant promises sows much disappointment Ambition is bitter as often as sweet; but without it, we'd be sunk.