Cormac McCarthy may be the most critically polarizing novelist in America today. For his many admirers, no comparison is too lofty: Mr. Mc-Carthy’s magniloquent language has been likened to Faulkner’s, his visionary morality to Melville’s, his elemental violence to Homer’s. But if Mr. McCarthy’s novels strive for a mythic power, they are also vulnerable to the puncturing skepticism invited by any form of magic. Unlike more temperate writers, who aim to convince if they cannot seduce, Mr. McCarthy demands an all-or-nothing commitment from the reader. Without it, his language begins to seem like rhetoric, his moral vision like melodrama, his violence crude and unreal.

“No Country for Old Men” (Alfred A. Knopf, 310 pages, $24.95), Mr. Mc-Carthy’s ninth novel, will do nothing to dislodge either admirers or skeptics from their entrenched positions. Like his Border Trilogy – “All the Pretty Horses,” “The Crossing,” and “Cities of the Plain” – which over the last decade promoted Mr. McCarthy from cult status to best-sellerdom, “No Country for Old Men” is a stark parable of good against evil, set against the equally stark landscape of the American Southwest. The plot, a rolling carnival of firefights, ambushes, and sadistic murders, would be merely thriller-level, were it not raised by Mr. McCarthy’s descriptions and digressions to the level of allegory.

The role of Satan in this South Texas morality play is taken by Anton Chigurh, a murderous psychopath whom we first see breaking out of jail by strangling a deputy with his handcuffs. The scene sets the tone for all the graphic violence to come: “He was gurgling and bleeding from the mouth. He was strangling on his own blood. Chigurh only hauled the harder. The nickel-plate cuffs bit to the bone. The deputy’s right carotid artery burst and a jet of blood shot across the room and hit the wall and ran down it.”

This sanguinary choreography might make us think of Peckinpah or Tarantino; but Mr. McCarthy scorns the inconsequential mock-violence of the movies, even as he borrows its techniques. The numb specificity of his prose is not a sign of jadedness, but of cosmic detachment: The gods, Mr. McCarthy suggests, view Chigurh’s brutality in just this way. Or at least the gods of South Texas, where landscape and history combine to build an amphitheater of violence: “The pale orange dust that hung in the windless morning light grew faint and then it too was gone. The barrial stood silent and empty in the sun. …The rocks there were etched with pictographs perhaps a thousand years old. The men who drew them hunters like himself.”

The hunter who sees those bleak traces is Llewellyn Moss, the Everyman who becomes Chigurh’s prey. The action of the novel is set off by Moss’s discovery, in the middle of the desert, of the remains of a drug deal gone bad: dead bodies, a truck full of heroin, and a briefcase containing more than $2 million in cash. There is no doubt in the reader’s mind that, from the instant Moss takes the money, his doom is sealed. As in Chaucer’s “Pardoner’s Tale” (or its latter-day retelling, “The Treasure of the Sierra Madre”), the treasure is its own curse.

Mr. McCarthy’s distinctive contribution to this old parable is the suggestion that, in fact, what dooms Moss is his failure to be wicked enough for his own crime. For one of the drug dealers that he finds is not quite dead, and the wounded man’s piteous cries for water lead Moss, the next day, to return to the scene of the crime with a full jug. And it is on this mission of mercy that Moss is detected by the rightful owners of the money, thus setting Chigurh on his scent. Moss, with his compassionate impulses – and his pure love for his child bride, Carla Jean – is no match for the implacable Chigurh, who makes it a rule to spare no one, ever. “You could even say that [Chigurh] has principles,” another character observes, and this inverted morality is what makes Chigurh not just a pulp villain, but a problem in theodicy.

The pathos and the limitations of Mr. McCarthy’s worldview, however, come across most clearly in his portrait of Sheriff Bell, the good angel struggling to save Moss’s life. Bell, a World War II veteran now almost at retirement age (the action takes place around 1980), is the book’s dominant moral presence. The action is punctuated by a series of italicized monologues, in which Bell looks back on the events of the novel and his past life. It would be unfair to tell exactly how Bell tries to counter Chigurh, or which of them finally decides Moss’s fate. But in fact, the twists of the plot matter less than Bell’s interpretation of them, according to what is plainly Mr. McCarthy’s own Stoic code.

And it is here, in Bell’s didactic moralizing, that Mr. McCarthy’s fictional universe becomes most questionable. For Bell’s ethics boil down to a very conventional manliness, borrowed (like Mr. Mc-Carthy’s hard-boiled, paratactic descriptions) from Hemingway, if not from Gary Cooper. Bell is the perfect expression of a familiar kind of post-1960s reactionary nostalgia: He is America’s Lost Father, brave but taciturn, with a natural command over men, women, and horses. He thinks nothing of sacrificing his life, but refuses to entertain any challenges to his authority. As a result, he feels deeply estranged from contemporary American culture:

These old people I talk to, if you could of told em that there would be people on the streets of our Texas towns with green hair and bones in their noses speakin a language they couldnt even understand, well, they just flat out wouldnt of believed you. But what if you’d of told em it was their own grandchildren?

Bell, then, is the old man of the title, and America is the country for which he is not suited – or, rather, which no longer deserves him. Like all nostalgias, however, Mr. McCarthy’s is blurry and blurring, and it finally turns the novel’s moral sternness into a species of sentimentality. Thus the psychopathic Chigurh comes to seem no more or less a sign of the times than the bad manners of the young: “Any time you quit hearin Sir and Mam the end is pretty much in sight,” Bell says, and it is clear that Mr. McCarthy means us to hear this as the wisdom, not the grumbling, of age. That Bell and the moral worldview he represents are passing away is certain; but only a writer like Cormac McCarthy, in thrall to a dubious myth of masculinity and the American West, could see this as an unmitigated loss.