Lewis Lapham takes the title for this elegant collection of sardonic and satirical essays about an American society he sees drowning in money from a poem by the Alexandrian Greek poet, C P Cavafy. "Why do the senators sit there without legislating?" Cavafy asks. It's because the barbarians are coming today and "once the barbarians are here, they'll do the legislating". Why are the consuls and the praetors wearing their best scarlet togas, and carrying canes beautifully worked in silver and gold? "Because things like that dazzle the barbarians."

"And now what's going to happen to us without barbarians?" Cavafy asks. "They were, those people, a kind of solution." The line suggests the dangers implied by the end of the Cold War. The barbarians Lapham fears are not without the city, but within. The editor of Harper's magazine, he is a moralist in the tradition of Gore Vidal: a scathing upper-class radical, as contemptuous of the barbarous taste of the Republic's new masters as he is disgusted by their greed and hypocrisy.

Republican politicians and the corporate culture are mercilessly peppered. Lapham says Newt Gingrich's book "will put to flight the evil spirit of moral decay, guarantee the profits of important business corporations ... and assure the nation's happy return to Colonial Williamsburg". And he jeers agreeably at such conservative fantasies as the "abstinence only" curriculum for sex education. "Sex in the United States", he rightly says, "is no laughing matter". Is it anywhere these days?

Lapham may be an archer - a nimble, lightly armed skirmisher, rather than a heavily armed knight - but he grasps some solid points. He is particularly severe about the way American conservatives try to pin moral decay on the fast-disappearing liberals, when it is the business culture itself that is destroying traditional moral values. "The loss of identity is good for business," he observes. Not mythical liberal villains, but Hollywood and television, helped by IBM and Microsoft, have destroyed the sense of history and left a generation without an ethical compass.

Lapham himself has a powerful grasp of ominous historical parallels. When he reads a memo saying that for a certain sum a political contributor can pay to play tennis on the White House court, he thinks of Aristotle's "prosperous fool", who made the mistake of imagining there is nothing money cannot buy. He also cites a prescient bookseller, writing in Paris in 1786: "finance has grown so powerful, so proud, so despotic that ... a fearful revolution is very imminent, we are very, very close to it". If only a handful are to be saved, like Isaiah's remnant, from the wrath to come, at least we can admire Jeremiahs who prophesy barbarism with such a wealth of allusion.

Lapham's message, however, is not literary escapism but plain political warning. "The retreat from the public forum lately has become a rout", he says, expressed not only as contempt for government, but as "a general loss of faith in national institutions". This is not only an American distemper.