On any American street, or in any airport or mall, you see the same sad tableau: A 10-year-old boy is walking with his father, whose development was evidently arrested when he was that age, judging by his clothes. Father and son are dressed identically -- running shoes, T-shirts. And jeans, always jeans. If mother is there, she, too, is draped in denim.

Writer Daniel Akst has noticed and has had a constructive conniption. He should be given the Presidential Medal of Freedom. He has earned it by identifying an obnoxious misuse of freedom. Writing in the Wall Street Journal, he has denounced denim, summoning Americans to soul-searching and repentance about the plague of that ubiquitous fabric, which is symptomatic of deep disorders in the national psyche.

It is, he says, a manifestation of "the modern trend toward undifferentiated dressing, in which we all strive to look equally shabby." Denim reflects "our most nostalgic and destructive agrarian longings -- the ones that prompted all those exurban McMansions now sliding off their manicured lawns and into foreclosure." Jeans come prewashed and acid-treated to make them look like what they are not -- authentic work clothes for horny-handed sons of toil and the soil. Denim on the bourgeoisie is, Akst says, the wardrobe equivalent of driving a Hummer to a Whole Foods store -- discordant.

Long ago, when James Dean and Marlon Brando wore it, denim was, Akst says, "a symbol of youthful defiance." Today, Silicon Valley billionaires are rebels without causes beyond poses, wearing jeans when introducing new products. Akst's summa contra denim is grand as far as it goes, but it only scratches the surface of this blight on Americans' surfaces. Denim is the infantile uniform of a nation in which entertainment frequently features childlike adults ("Seinfeld," "Two and a Half Men") and cartoons for adults ("King of the Hill"). Seventy-five percent of American "gamers" -- people who play video games -- are older than 18 and nevertheless are allowed to vote. In their undifferentiated dress, children and their childish parents become undifferentiated audiences for juvenilized movies (the six -- so far -- "Batman" adventures and "Indiana Jones and the Credit-Default Swaps," coming soon to a cineplex near you). Denim is the clerical vestment for the priesthood of all believers in democracy's catechism of leveling -- thou shalt not dress better than society's most slovenly. To do so would be to commit the sin of lookism -- of believing that appearance matters. That heresy leads to denying the universal appropriateness of everything, and then to the elitist assertion that there is good and bad taste.

Denim is the carefully calculated costume of people eager to communicate indifference to appearances. But the appearances that people choose to present in public are cues from which we make inferences about their maturity and respect for those to whom they are presenting themselves.

Do not blame Levi Strauss for the misuse of Levi's. When the Gold Rush began, Strauss moved to San Francisco planning to sell strong fabric for the 49ers' tents and wagon covers. Eventually, however, he made tough pants, reinforced by copper rivets, for the tough men who knelt on the muddy, stony banks of Northern California creeks, panning for gold. Today it is silly for Americans whose closest approximation of physical labor consists of loading their bags of clubs into golf carts to go around in public dressed for driving steers up the Chisholm Trail to the railhead in Abilene.

This is not complicated. For men, sartorial good taste can be reduced to one rule: If Fred Astaire would not have worn it, don't wear it. For women, substitute Grace Kelly.

Edmund Burke -- what he would have thought of the denimization of America can be inferred from his lament that the French Revolution assaulted "the decent drapery of life"; it is a straight line from the fall of the Bastille to the rise of denim -- said: "To make us love our country, our country ought to be lovely." Ours would be much more so if supposed grown-ups would heed St. Paul's first letter to the Corinthians, and St. Barack's inaugural sermon to the Americans, by putting away childish things, starting with denim.

(A confession: The author owns one pair of jeans. Wore them once. Had to. Such was the dress code for former senator Jack Danforth's 70th birthday party, where Jerry Jeff Walker sang his classic "Up Against the Wall, Redneck Mother." Music for a jeans-wearing crowd.)

georgewill@washpost.com