Robert Baden-Powell, the British military hero who founded the Boy Scouts, had an intense interest in teenage boys and their bodies. This interest expressed itself with a forthright innocence that to our post-Freudian sensibilities seems to have pretty clear sexual overtones. There is no evidence that Baden-Powell ever acted on this aspect of his enthusiasm for youth, and scouting enthusiasts both deny and resent the implication.

But the specter of what was on Baden-Powell's mind might well make modern American parents reluctant to send their sons off for a wholesome weekend in the woods with scoutmaster Bob. And it would probably doom efforts by someone similarly inclined to start an organization like the Boy Scouts today. Would that be a good thing?

Millions of American adults dedicate their lives to serving young people as teachers, coaches or spiritual advisers. Roman Catholic priests, in particular, dedicate themselves to a degree most of us cannot even imagine. Why do they do it? Sheer goodness can explain a lot, but not everything. Even the most saintly among us is moved by a complex stew of motives, some admirable and some less so, some conscious and some unconscious. The sin of pride, for example, helps seduce many into goodness.

Fear of real life is part of what tempts some into the cloister. And for a small fraction of those youth-serving millions, sexual longing plays a role. Even many of those who put themselves among young people for reasons that are partly sexual probably do so with no conscious predatory intention. They may hope to gain some pleasure from mere propinquity, and also from helping young people in wholly admirable ways. Some are fooling themselves, with disastrous consequences.

But many undoubtedly succeed in their lifetime project of service and self-denial, doing much good and no harm. They are surely more heroes than predators. Societies other than the U.S., while not exactly laughing off the sexual abuse of children, manage to acknowledge this reality without the same episodic hysteria. In England, for example, the "randy vicar" is a stock comic character. And even in America we recognize and tolerate the inevitability of certain tendencies that have occasional antisocial consequences.

The military services would have a harder time filling their recruiting quotas if they were successful in screening out everyone with an unhealthy enthusiasm for violence. Instead they work to control and channel those impulses, and they largely succeed. Sure, there is a pretty obvious distinction between thinking illicit thoughts and acting on them.

But it is not so easy to purge the actual predators without punishing those heroes of sublimation or losing their valuable contributions to society. Why? Because the line is hard to draw in practice. Is the football coach who spends a bit too long towel snapping in the locker room after the game a predator or a sublimator?

Because fear of succumbing to temptation must surely plague even those who remain steadfast, and imposing ruination as the cost of succumbing will drive such people away -- or condemn them to a lifetime of psychological torture. Because, finally, even this obvious distinction between thinking and acting is being swept away in the nation's current frenzy over predatory priests. The correct response to all this may well be: too damned bad. Protecting children is more important.

But at least these considerations ought to make us appreciate the dilemma of having officially designated bad guys. The Roman Catholic Church is far and away America's biggest social-service agency. As such it does a tremendous amount of good: tending the sick, feeding the hungry, counseling the troubled and running a school system that is the envy of secular educators public and private. So what were Boston's Bernard Cardinal Law and other church officials thinking when they covered up sexual abuse of boys and girls by priests and allowed the offenders to start again in new parishes with fresh, unaware victims?

Maybe they were thinking that God works in mysterious ways and that all this good work may depend in part on people who are doing good for bad reasons. Maybe they were thinking that protecting the church's supply of such necessary people involves a trade-off, a balancing of considerations.

There is no question that Law and his colleagues got the balance badly wrong. But at least we should try to understand why they may have thought there was one. Understand, and maybe even sympathize a bit. Michael Kinsley is founding editor of Slate.com