David Mamet, considered by some to be the greatest living playwright, has proclaimed for all to hear - but few to listen - that he is no longer "a brain-dead liberal."

Mamet uses the phrase "brain-dead liberal" in quotation marks precisely because he was never actually brain dead. Rather, he just told the relevant parts of his brain to play dead whenever inconvenient facts staged an assault on his cranial bunker.

"As a child of the '60s," he recently wrote in a startling and lively essay for the Village Voice, "I accepted as an article of faith that government is corrupt, that business is exploitative, and that people are generally good at heart."

But Mamet has changed his mind. The accretions left from wave after crashing wave of reality made it impossible for him to carry the load of his cognitive dissonance. For years he'd called NPR "National Palestinian Radio." He'd realized that while government may be incompetent, corporations at times myopic, and the military imperfect, seeing politics through the prism of a Thomas Nast cartoon (you know, where industrialists are cast as pigs in tuxedos feeding at the public trough) might not be as wise as, say, The Village Voice believes it is.

"I began reading not only the economics of Thomas Sowell (our greatest contemporary philosopher) but Milton Friedman, Paul Johnson and Shelby Steele ... and found that I agreed with them: a free-market understanding of the world meshes more perfectly with my experience than that idealistic vision I called liberalism."

Mamet invokes John Maynard Keynes' response to criticism that he changed his mind: "When the facts change, I change my opinion. What do you do, sir?"

Michael Billington might have a different response. "I am depressed to read that David Mamet has swung to the right," wrote the Guardian's theater critic of more than three decades. "What worries me is the effect on his talent of locking himself into a rigid ideological position."

This response is quite simply perfect, a Picasso of asininity, a Mona Lisa of moronic imbecility.

Mamet, a dashboard saint of angst-ridden cosmopolitan liberalism, has set out to read widely and carefully, exploring how his outdated political pose no longer tracks with reality or with his own understandings of the world, and Billington worries that Mamet is locking himself into a rigid ideological position.

Mamet has, Houdini-like, gone through the painful process of regurgitating a key to the chained-up straitjacket in which he'd been trapped, and after the required internal dislocations has emerged to think freely about the world, and this guy somehow thinks Mamet's trapped himself.

The playwright has explicitly rejected dime-store Marxist categorical thinking, embracing instead the idea that whatever differences people bring to the stage of life based on their varied experiences, human nature is universal (at least to humans) and people are, well, people. Of course, some are evil, some good, most a complicated mixture of the two. But simply because a person represents or works for The Government or Big Business - or, for that matter, Fashionable Minority X, Y or Z - doesn't mean you know all you need to know about them. A business card is not a Rosetta stone for deciphering a man's soul.

But don't tell this to those who define sophistication and nuance by a work's ability to confirm preconceived notions. A writer in The Independent frets that "so complex and profound and gifted a playwright should now seek to reduce his own work and his own politics to simple concepts." People like this see more complex hues in, say, George Clooney than in a painter's color wheel.

Clooney proclaimed not long ago, "Yes, I'm a liberal, and I'm sick of it being a bad word. I don't know at what time in history liberals have stood on the wrong side of social issues." Ah, yes, there's fine-tuned, historically informed thinking on display!

Mamet has committed the sin of free-thinking in a world that defines it as "ideological rigidity" while dubbing conformity "diversity." Already, critics are saying his work is slipping. Soon, they will say his work was never that great to begin with (that's what they've been doing to Dennis Miller for his heresy). The more Mamet rejects the divine pieties of the left and thinks for himself, the more the Greek chorus of straitjacketed "free thinkers," their heads shaking in unison, will tsk-tsk Mamet's rigidity.