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…

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.