Every so often on my walk to work on Capitol Hill, I find myself in earshot of a group of students heading to school. And what I sometimes hear from these kids catches me off guard. It's not just the "F" word, or who is getting "dissed" or sleeping around. It's that these kids - 11, 12, 13 years old - hardly talk or act like kids at all.

Social critics like Neil Postman have long noted the disappearance of childhood in America: the fact that when it comes to vulgarity, sex and violence, our children are acting more and more like brutish adults. But what many fail to realize is that this condition is much less a cultural accident than the result of conscious human design.

"Childhood is disappearing for millions of kids because of the triumph of an unprecedented idea," writes Kay Hymowitz in Ready or Not: Why Treating Children as Small Adults Endangers Their Future - And Ours. It is the notion that children are rational and self-sufficient, endowed with all the qualities necessary to enter the adult world. Under this view, the job of parents is simply to empower their children, not to correct and morally instruct them.

If this remnant of romanticism were confined to a handful of fringe academics, it wouldn't pose much of a problem. Instead, says Ms. Hymowitz, a scholar at the Manhattan Institute, it is being advanced by those who mold our understanding of children - including psychologists, child advocates, educators and advertisers.

These elites don't openly reject the idea of childhood. Rather, they have redefined the child's nature as being ripe with moral goodness. Nineteenth-century literature was filled with cautionary tales of children behaving badly - and facing the consequences. Today, third-graders on "South Park" swear like drunken soldiers, and it's played for laughs. Apparently children no longer need to learn moral lessons, and they never require punishment. After all, writes best-selling author Robert Coles, children are possessed of an admirable "moral intelligence."

Similarly, one of the nation's most influential experts on character development, Carol Gilligan, says the kids are all right; it's the adults who are the problem. Attempts to impose rules about homework or sharing with classmates leads to "psychological footbinding." This explains why some school districts give out condoms to fifth-graders. Best to simply get out of the way and watch them mature.

Educators are infected with this thinking. The rise of the whole-language approach to reading assumes that children are naturally inclined toward literacy. Teachers tout "discovery learning" or "child-centered" curricula, while producing kids who can't read or write. More important, the relationship between teacher and student has changed: Rather than handing down the knowledge deemed indispensable to learning and life, teachers merely "enable" students to learn on their own.

Advertisers, meanwhile, are agressively targeting pre-teens, seducing them with images of kids who are cool, tough and independent. Barbie doll ads declare "you, girls, can do anything." A cosmetic line, Sweet Georgia Brown, offers body paints and scented body oils for children. Retailers such as Limited Too, Gap Kids, and Abercrombie and Fitch have opened stores for 6- to 12-year-olds and are selling the new look. "The seduction of children with dreams of teen sophistication and tough independence has undermined childhood by turning children into teen consumers," Hymowitz writes.

The message from our cultural elites is the same: Children must be set free from the suffocating embrace of convention, tradition and religion. But as Ms. Hymowitz warms, children will not be liberated, they will be dominated - left to the ravages of the marketplace and their morally ambivalent peers. Surely this helps explain why 4 million children, more than double the number in 1990, are now taking Ritalin; why our juvenile-court system is filled to overflowing; and why the teen suicide rate has risen 95 percent since the 1970s.

It shouldn't take the shooting deaths at Columbine High School to convince us that something is wrong with this approach. If parents hope to prepare their children for adulthood, they must begin by recovering a time-tested religious insight: Children are born not with wisdom, but with self-centered willfulness. "We are not merely imperfect creatures who need to be improved," wrote C.S. Lewis. "We are rebels who must lay down our arms."

Only secular "experts" could convince themselves otherwise. Yet the new millennium has not given us a new nature, and the moral education of children still requires a massive dose of adult supervision. Just ask any parent with a toddler at home.