I was watching an antidrug video with my middle school daughter a few days ago, listening to heartbroken parents recount how drug addictions had claimed their beloved teenagers' lives.

A pattern began to emerge: Each kid had made it through rehab, stayed clean for a while, then relapsed and overdosed. One bereaved parent commented that after being off drugs for a while, her daughter's body couldn't handle the stronger doses it had once needed.

That was tragic hindsight. Is anyone warning the addicts before it's too late?

The same day I saw that video, I took a young unmarried friend to a crisis pregnancy center. She was giddy with relief to find out she wasn't pregnant.

"I do want to have children someday," she said, "but it wouldn't be fair to the child to have it now."

Well, then, you have two choices, I told her. You can stop having sex with your boyfriend, which is the choice you know you ought to make, or you can use protection, which will at least minimize the damage.

Failure is not an option, or so the popular catch-phrase goes. But when it comes to human nature, not only is failure always an option, it's a pretty safe bet.

We adults fail regularly. We fail to meet deadlines, we sometimes break our vows, we don't always drive carefully, and we may occasionally drink too much. Hopefully we don't make all these mistakes simultaneously.

Knowing others' shortcomings, and our own, we save for a rainy day, carry insurance, appoint a designated driver, go to counseling, and learn to say, "I'm sorry. I was wrong. Please forgive me."

As adults, we protect ourselves from as many of the consequences of failure as we possibly can. Why should we force a harsher moral standard on our kids?

The answer I keep encountering is that if we prepare our children for possible failure, we make failure more likely. If we tell them how to protect themselves from the more dire consequences of foolish choices, we give them permission to go wild.

That's the reasoning (flawed, I think) behind some religious conservatives' opposition to the new vaccine that protects girls from cervical cancer caused by a sexually transmitted virus.

But surely there's a balance between an enabling permissiveness on one hand and vengeful moralism on the other. Should we call this balance "compassionate realism"? "Moral pragmatism"?

Drug specialists simply call it "harm reduction," said Dr. Neil Capretto, medical director at Gateway Rehabilitation Center. Since research shows that the "all or nothing" approach to rehabilitation doesn't work, he said, staffers are trained to tell recovering addicts how their bodies will respond if they relapse.

"And many will relapse," he said. "If you try to pick up where you left off, it could kill you. That's a message we try to get out. Whether they hear it or pay attention, I don't know."

As we talked about protecting the vulnerable, Dr. Capretto made the analogy to wearing a seat belt. You intend to be a good driver, but you may have a moment's distraction, or the other driver may be drunk.

If you apply the seat belt analogy to addiction, drug use is a "car" no one should ever drive. The best protection is early education that instills a very healthy dose of fear.

Some would say the same of sex -- a car you shouldn't drive without a license, but a majority of us do. A young woman, in fact, could attain God's ideal and remain chaste until marriage but still catch a cancer-causing virus from her less-chaste spouse.

Is there a drop of mercy anywhere in the moral position that would condemn young women to early deaths for having had sex when they ought not?

The rigorous moralists surely know the parable of the prodigal son, who took a substance he shouldn't have -- his inheritance -- and went far away to live as he liked. He finally hit bottom, sleeping in a pig sty, coveting the slop.

"When he came to his senses," the Gospel of Luke says, he got up and went home to his father.

We -- failures, one and all -- are not condoning failure when we provide clean needles for addicts, recommend vaccinations for young women, give relapse info to the newly sober, or recommend birth control or condoms to the foolishly promiscuous.

We make sure they know where "home" is, and then we just try to keep them alive till they come to their senses.