In America the young are always ready to give to those who are older than themselves the full benefits of their inexperience. -- Oscar Wilde, dead white man

The celebrated English wit was right, and usually in the past adults weren't afraid to be old fogies, ready to shake an index finger at childish behavior. It was about helping the young grow up with a sense of responsibility. But somewhere in the last half of the 20th century a permissive culture put the children in charge. The wisenheimers who four decades ago vowed never to trust anyone over 30 are themselves over 60 now, but the residue of that permissiveness lingers still. It hurts the underclass most of all.

This is hardly news to anyone paying attention. The '60s generation that rebelled against the Man in the Gray Flannel Suit is still triumphant in the popular culture dictated by Hollywood, where men in tuxedos show up for formal occasions in tennis shoes, without ties. The rich and famous can always get away with such things. The underclass has less wiggle room, and their rebelliousness is considerably more off-putting than their fashion in dress (though baggy prison pants doesn't do them any good).

What is news is that two prominent black men are now speaking out in a fresh way, calling for an end to what has come to be known as ghetto culture. We're not talking about Al Sharpton or Jesse Jackson, purveyors of the victim scam. The prophets for change are Bill Cosby, the entertainer, and Alvin Poussaint, the professor of psychiatry at Harvard Medical School. Their new book is called "Come On People: On the Path from Victims to Victors."

Bill Cosby, famous for his television sitcom depicting an ordinary middle-class family, a kind of black "Father Knows Best," focuses now on blacks who haven't cracked the middle class. He's gone from acting to preaching, and he's delivering a powerful sermon he heard from a pastor in Wilmington, Del.

This pastor, Cosby told Tim Russert on "Meet the Press," talks about discipline through "shakedown." In a prison shakedown, guards go through the cells to search for drugs and crude handmade weapons. Rev. Derrick Johnson, who is also known as Pastor D, tells his congregation to call a "shakedown" of your child's room: "Your child didn't buy that room, your child's not paying rent. You're trying to keep your child from being murdered, from going to jail. Look under his mattress, make sure your kid doesn't have a gun. Look into materials on the wall. What is your kid talking about? Is it dangerous? This is part of love, and this is what we have to do, regardless of race, color or creed."

Bill Cosby moves from the room to the culture. He demands an end to obscene lyrics that degrade women, that endlessly recite the "N-word." When white ladies offered a similar message more than 20 years ago, they were excoriated by Hollywood glamorosos as do-good censors. Here's Bill Cosby 20 years on: "The N-word is a vile symbol of our oppression by slave masters." It's no more acceptable for blacks to use it than for whites. He tells of a friend whose record producer asked him to write rap about rape. "You're talking about my mother," the writer said. "Well," the producer responded, "if you don't want to write it, then I'll get somebody else who will."

Gangsta rap may make a young black man feel tough, Bill Cosby observes, "but not so tough he can walk through prison walls." It can "jazz" young men into sexual passion, but it can't make them good fathers.

It has not been easy to say such things in public without inviting sneers and scorn, and Cosby and Poussaint have taken their share of ridicule and disdain. But they sound like grown-ups with common sense, offering advice to children that will ultimately turn into dollars and cents. They prescribe teaching standard English as a first language, even suggesting that blacks watch "My Fair Lady." Speaking properly lends confidence and competence. The new path requires a fundamental change of the walk and the talk, of attitude: "Blaming white people can be a way for some black people to feel better about themselves, but it doesn't pay the electric bills."

Art and morality are often at odds. Artists push the envelope of civility and decency. But we live in an age where the mark of the lowest common denominator misleads the most vulnerable among us. "Come On People" isn't just about blacks. It's a cry for all of us to get our act together. It's about time the culture grew up.