WASHINGTON — When Charles Murray and Richard J. Herrnstein’s book “The Bell Curve” appeared in 1994, it was denounced by social scientists, liberal pundits and a little-known Chicago civil-rights lawyer named Barack Obama, who in a commentary on NPR accused the authors of calculating that “white America is ready for a return to good old-fashioned racism as long as it’s artfully packaged.”

Anyone who remembers the firestorm over that 845-page doorstop’s dense arguments about race, class, genetics and I.Q. might be tempted to look at the cover of Mr. Murray’s latest book, “Coming Apart: The State of White America, 1960-2010,” and think, “Here we go again.”

But “Coming Apart,” which depicts members of white elites as hypocrites living in a bubble and the white working class as succumbing to moral decay, is hardly a flattering portrait of white people, let alone, Mr. Murray insists, a partisan barnburner.

“It’s not a brief for the right,” Mr. Murray said in a recent interview at the American Enterprise Institute here, where he has been a scholar since 1990. “The problem I describe isn’t a conservative-versus-liberal problem. It’s a cultural problem the whole country has.”

“Coming Apart,” which shot to No. 5 at Amazon.com immediately upon publication last week, has certainly prompted much conversation, if little in the way of consensus. David Brooks, a columnist for The New York Times, pre-emptively declared it the most important book of the year, saying, “I’ll be shocked if there’s another book that so compellingly describes the most important trends in American society.”

But to critics on the left Mr. Murray’s arguments are just an effort to change the subject. Defining the problem as one of cultural inequality instead of economic inequality, as the New York Magazine blogger Jonathan Chait put it, allows one to start talking about marriage and industriousness and “steer the debate back onto comfortable conservative terrain.”

Looking at America Mr. Murray sees a country increasingly polarized into two culturally and geographically isolated demographics. In Belmont, the fictional name Mr. Murray gives to the part of America where the top 20 percent live, divorce is low, the work ethic is strong, religious observance is high, and out-of-wedlock births are all but unheard of. Meanwhile in Fishtown, where the bottom 30 percent live, what Mr. Murray calls America’s four “founding virtues” — marriage, industriousness, community and faith — have all but collapsed.

The book says little about the roots of Fishtown’s problems, but in conversation Mr. Murray doesn’t hesitate to name the villain. “The ’60s were a disaster in terms of social policy,” he said. “The elites put in place a whole set of reforms which I think fundamentally changed the signals and the incentives facing low-income people and encouraged a variety of trends that soon became self-reinforcing.”

It’s an argument familiar from Mr. Murray’s 1984 book, “Losing Ground,” which established him overnight as a major policy intellectual and helped lay the groundwork for the 1996 law overhauling welfare. But in “Coming Apart” Mr. Murray’s recommendations are both more vague and far more ambitious. The first step, he writes, is for the people of Belmont to drop their “nonjudgmentalism” and lecture Fishtown on the importance of marriage and nondependence: to “preach what they practice,” as Mr. Murray puts it.

Next they need to leave their upper-middle-class enclaves and move closer to Fishtown.

That’s exactly what Mr. Murray said he did two decades ago, when he and his second wife, Catherine Cox, a retired English professor, moved from Washington to Burkittsville, Md., a historic rural town of about 170 people about 50 miles to the northwest.

“I did not want my children to grow up only knowing other upper-middle-class kids like themselves,” said Mr. Murray, who has two children with Ms. Cox and two from his first marriage. “That was a very conscious worry shared by my work.”

Life in Burkittsville, as he described it, approximates the small-town virtues he enjoyed growing up in Newton, Iowa, where, as the son of a manager at Maytag, he could mingle easily with the children of assembly-line workers.

In Burkittsville, he said, he and his wife attend Quaker meetings and enjoy friendships with both other professionals and blue-collar tradespeople, whose travails he cited to counter the suggestion that the problems described in “Coming Apart” might have something to do with the disappearance of working-class jobs.

Until the recession hit, Mr. Murray insisted, his blue-collar friends were eager to hire apprentices at good wages but struggled to find anyone willing to do the work. “They are looking at a marked deterioration in industriousness that is real and palpable,” he said.

Mr. Murray’s critics jump on such moralizing arguments, saying they blithely ignore a large body of research on the causes of family breakdown among the working class.

“He wants to go back and blame the counterculture for everything,” Claude S. Fischer, a sociologist at the University of California, Berkeley, said in a telephone interview. “But the huge majority of social scientists would say it’s the economic downturn suffered by the less educated in the last generation.”

Mr. Murray, who has a Ph.D. in political science from M.I.T., is well aware of his fraught standing among his fellow social scientists, noting in the acknowledgments of his latest book that being thanked by him “can cause trouble for people in academia.” But he described himself as “almost completely rehabilitated” since the fracas surrounding “The Bell Curve,” saying, “I am no longer a complete pariah in some academic quarters.” Still, he receives few invitations to speak on campuses, and an appearance last spring at Earlham College in Indiana was interrupted twice by a pulled fire alarm.

His real audience, though, is not academia but policy makers and ordinary people.

Both groups could find “Coming Apart” challenging. It seems unlikely that any politician will take up Mr. Murray’s call to replace all federal income-transfer programs with a modest guaranteed income for all Americans age 21 and over. He’s “completely unwired” in partisan political circles these days, Mr. Murray insisted, adding, “Neither party wants to say, you know, we’ve got a real problem with the working class being less and less able to participate in American life.”

Mr. Murray may have just as hard a time persuading his comfortably upper-middle-class readers — liberal or conservative — to leave behind the nice houses (not to mention the top public schools) of Belmont and find their own Burkittsville.

But whatever happens, Mr. Murray, who turned 69 recently, vowed that “Coming Apart” would be his last major statement about the relationship among virtue, happiness and public policy.

“If I can’t persuade people at this point, I’m not going to persuade them with another book,” he said.

Not that Mr. Murray has had his own mind changed about much. He said he saw no real contradiction between his staunch libertarian faith in freedom of choice and his old-fashioned moralist’s dismay at where choice often leads.

Asked if he had ever reversed himself intellectually, he thought for a few minutes before coming back to “The Bell Curve,” whose arguments about a genetically advantaged “cognitive elite” he reprises in “Coming Apart.”

Working on “The Bell Curve,” he said, “brought home to me the extent to which in an age when cognitive ability is getting more and more important, and people are born into the world getting the short end of the stick in that regard, I think I’m more sympathetic than I used to be to taking that into account with public policy.”

“But that doesn’t make me very sympathetic,” he quickly added, with a laugh. “I still want to find a way that leaves people free to live their lives without telling them what to do.”