The Secret Knowledge: On the Dismantling of American Culture. By David Mamet. Sentinel; 226 pages; $27.95. Buy from Amazon.com

 The zeal of a convert

IN 2008 David Mamet, an American playwright, essayist, screenwriter and director (best known for his brilliant play, “Glengarry Glen Ross”), wrote a scathing article in New York's Village Voice under the title “Why I Am No Longer a Brain-Dead Liberal”. It was a bracing shock to the paper's earnestly liberal readership, which was challenged by such Mamet aperçus as “…tallying up the ledger in those things which affect me and in those things I observe, I am hard-pressed to see an instance where the intervention of the government led to much beyond sorrow.”

A provocative newspaper article for the New York in-crowd is one thing; a full-length book justifying Mr Mamet's Damascene conversion to the way of Friedrich Hayek and Milton Friedman quite another. For all Mr Mamet's skill with words, this is a tedious and simplistic rant (government bad; unhampered individuals good, and so on). Economics and politics are reduced to caricatures, with no room for nuance (“the Israelis would like to live in peace within their borders; the Arabs would like to kill them all”). Social policy is reduced to banalities (affirmative action is against the Constitution; “the Liberal Arts University has had it”). And, of course, global warming is a myth.

The editorial inaccuracies also detract. Mr Mamet praises Dambisa Moyo, a Zambian economist and author, for her criticism of foreign aid, but identifies her as a Gambian. (One country is in southern Africa, the other in the west, but, hey, why should a misplaced consonant spoil the argument of a true conservative?) He rails against American health-care reform but seems to think only 20m people are uninsured (the latest estimates reckon the figure is just over 50m).

Fortunately for the reader the rant comes in short segments: there are 39 chapters, none more than a handful of pages long—which means Mr Mamet's notions are more easily digested than might be possible at greater length, and at bite-size they can be wonderfully entertaining. Even a brain-dead liberal should appreciate the surgical finesse with which Mr Mamet punctures the pomposities of Gloria Steinem and Susan Sontag. Only rarely does his prose slump into risible clumsiness (“Culture exists and evolves to relegate to habit categories of interactions the constant conscious reference to which would make human interaction impossible”).

As a polemicist Mr Mamet is impressive—but at the cost of intellectual honesty. When he was a “brain-dead liberal”, his plays and films underlined the flaws of Western society and capitalism. But as a born-again conservative he more or less ignores the global financial crisis that followed the credit crunch (“the foreseeable bust of 2008”), and he skates blithely over the disasters of the Iraq war.

Mr Mamet's vehemence commands a certain admiration. “Liberalism”, he writes, “is a religion. Its tenets cannot be proved, its capacity for waste and destruction demonstrated. But it affords a feeling of spiritual rectitude at little or no cost.” Maybe so, but as an apostate from liberalism Mr Mamet has simply embraced a new religion—with all the excessive zeal of the recent convert.