The debate is an old one, and our disagreement remains as fierce as our anxiety.

On the highly emotional subject of teen-age sex and its risk, teen-age pregnancy, we argue about the causes and about the cures with growing intensity.

Is it all the result of liberation or immorality, sexism or equality, ignorance or education, family neglect or government intervention? Have sex education and birth-control clinics promoted teenage sex and prevented teen-age pregnancy? Our concern for our children's lives supplies ample energy to fuel this debate through the decade.

Now we have a new and powerful captain of one team, Richard Schweiker. As point man for the new right, the secretary of health and human services went on record recently against government roles in either contraception or sex education. He told reporters that he was against prescribing birth control for unamrried teen-agers under Medicaid and opposed to government involvement in sex education.

He took over the role as leader of the "pro-family" side in this medical-moral issue. And in doing so, he drew on the popular notions that somehow or other the "experts" are part of the problem instead of the solution, that somehow or other the programs are encouraging teen-age sex in the gulse of controlling teen-age pregnancy.

This idea, one that grips so many of us, rests on shaky historical grounds. Teen-age sex -- under another name, premarital sex -- is as old as people. Even in the "repressed" 1950s, 25 percent of the women and more of the men had sex before age 20. At least half of the teen-age marriages were what we used to call so charmingly "shotgun weddings."

Teen-age sex in the 1960s grew in part out of the exposure of these "underground" facts of life. It also grew out of the simultaneous glorification of sex in the media. From rock lyrics to movies to ads, we were given a hard sell and teenagers turned into some of the more guillible consumers.

If the "sexual revolution" for adults was based in part on the availability of birth control for adults, it is only naturual that this affected those half-adults, teen-agers. But this trend was set into motion before the first federally funded birth-control clincs were open to teen-agers. In terms of sex education, then as now, it was overwhelmingly the business of local school boards, not the federal government.

As Frank Furstenberg, a sociology professor at the University of Pennsylvania and long-term researcher in the field says, "Whatever the government did, it did in response to the problem. They didn't create it."

Why then is the debate so heated? Surely part of the reason for the backlash against the experts is that they promised more than they could deliver. Parents were looking for a prescription of protection. If pregnancy grew out of ignornace and accident, the professionals offered education and prevention. Now we know it isn't enough.

Family planning clinics have helped stem the rise of the "epidemic of teen-age pregnancies," but they haven't turned it around. Neither sex education nor birth control clinics have -- or probably could have -- drastically affected the increase in teen-age sexual activity.

So even if the experts have not handed out typhoid blankets of sexual information to our children, they have also not provided the perfect vaccine against their exposure.

But the more emotional part of the parent backlash has grown out of our anxiety about the fact that sex educators and family planners are talking directly to our children, giving them messages with which we may or may not agree. It feeds our real sense that somehow or other we have lost control or moral influence in this crucial area of our children's lives.

It is easy to cry, as Schweiker has, that the government has interfered in family matters, taking away this function. It isn't that simple. But the professionals and parents have become the "us" and "them," suspicious or at best separate.

The real task, then, is not to fuel this debate with foolish accusations and devastating budget slashes. It's not to get government out of this volatile area of our children's lives but to get parents back in. For this we need, and are just beginning to forge, a new partnership.