It's what America's founders worried about 200 years ago. ''Will you tell me how to prevent riches from becoming the effects of temperance and industry?'' Adams asked Jefferson. ''Will you tell me how to prevent luxury from producing effeminacy, intoxication, extravagance and folly?'' It's what social critics worry about today, with books like ''Luxury Fever,'' ''The Overspent American'' and so on and so on.

And yet, somehow, America has this amazing ability to not decline. America's history doesn't follow the normal life cycle of nations. American standards of living actually surpassed European standards of living around 1740. For about 260 years, in other words, America has been rich. And yet decline hasn't come; Gibbon would have nothing to write about here. American workers are still the most productive on earth, two-thirds more productive than our counterparts in Great Britain, for example. American technology is still the envy of the world, and her universities are the queens of learning. Three-quarters of the Nobel laureates in economics and the sciences over the past few decades live and work in the United States. Spending more on defense than the next 15 nations combined (while still devoting only around 3 percent of the G.D.P. to the military), America is now the undisputed great power of the globe. And as the Yale historian Paul Kennedy wrote recently in The Financial Times, never before in human history has the disparity between the world's greatest power and the next greatest power been so wide.

Moreover, despite all the social-critic jeremiads, Americans have shown this remarkable tendency to remain undecadent. Look, for example, at how we spend our money. Michael J. Weiss summarized the latest Consumer Expenditure Survey in the April issue of American Demographics. He reports that during the 1990's, which was the great fizzy decade of splendiferous stock-market returns and walloping prosperity, Americans spent less on just about every item on the Hugh Hefner/Larry Flynt/Maxim magazine/Robb Report repertory. Americans in 2000 spent less than they did 10 years earlier on steaks, martinis, cigars, jewelry, watches, furniture, toys and sound equipment. They spent less on entertainment and more on education, housing, transportation and computers. Americans spent 10 percent less on food in general (though baby boomers spent 15 percent more on fresh vegetables). Americans spent 14 percent less on clothing, the largest decline in any category, though they did spend 12 percent more on shoes.

Overall, this is not a picture of a nation of orgiastic self-indulgence. Furthermore, despite all of our earnest resolutions, Americans are still terrible at languorous ease. We can't take a vacation for a week without bringing our laptops along, let alone laze away at health spas for weeks on end slicing sausages, the way the Germans do. American beaches still aren't Rio-style thong expos, nor are they southern European nudist zones, where 70-year-old women who grew up with corsets and propriety suddenly get the urge in advanced retirement to throw off the vestments of civilization and let the vein patterns protrude in the breeze. Despite leadership from the top, we haven't really learned to relax about adultery, and serious sex surveys do not depict a nation of serious kinkiness and sensuality. Picture a typical American man going on the Internet looking for some pornography. In a few minutes he can't help himself: he's clicked over to LendingTree.com and he's checking out the latest mortgage rates. His sexually bored wife bursts in on him with disgust etched in her voice: ''What is it men have about refinancing? Can't you at least look at a few leather or barnyard sites and at least pretend to enjoy yourself?''

The reason America hasn't been corrupted by all its wealth is that in this country we have transformed the nature of money. If you have enough of it, and you are sloppy enough with it, and if you have a system that promiscuously sloshes it around from the deserving to the undeserving and back again so that there are great flows of wealth oozing all over the place and great tales of opportunity in every ear, then pretty soon money is no longer just a thing you hoard in the bank. Money has become the environment, and that changes the way it affects people.

Money in America has been transformed into abundance. In the realm of money, money is scarce. But in the realm of abundance, money is promiscuous. And this environment of abundance comes with its own psychology, morality, sins and virtues. It does not create the old corrupting patterns described by the philosophers.

The abundance mentality starts with the unconscious premise that there exists, at all times, close by, a happy hunting ground, a valley where acres of diamonds are there for the picking. In the land of abundance, work is worth it, because it is often rewarded. In the land of abundance, a person's lower-class status is always temporary. If the complete idiot next door has managed to pull himself up to the realm of Lexus drivers, why shouldn't the same thing happen to you?