Doctor Laura, the second-hottest thing in talk radio, often intrudes on my expressway reveries. Turn her on and it is hard to turn her off. People call in to spell out their dilemmas, and she, quick of brain and tongue and judgment, utters her dicta with all of the finality of a guillotine blade.

Dr. Laura Schlessinger attracts many who applaud the fact that she lives by absolutes, cites the Ten Commandments, and contends mightily against something worth contending against--a phenomenon now called "postmodern relativism." She is entertaining, not always wrong, and not as destructive as she might seem of everything every counselor is taught.

As 100 percent of the public must know by now, Laura's past has come to haunt her recently, the way Thomas Jefferson's past has come to haunt our memory of him. Some old photos of her in suggestive nude postures recently made their way into cyberspace, thanks to a scumbag with whom she was having an affair a marriage ago. As 99 percent must know, Dr. Laura sued to retrieve the irretrievable pictures, and lost.

With the law and her lies behind her, Dr. Laura did what people do now: she was contrite, repentant and full of resolve. In her newspaper column she followed up with a rather eloquent defense against charges of hypocrisy, while taking swings at those who question her past life and  current explanations. She credits the change in her life to her conversion, or reconversion, to Judaism.

"Having once lived a way that one now disavows on moral and ethical grounds does not make one a hypocrite; it makes one a teacher," she says. Is she right that we are better taught by people who did bad things, then got smart and converted--genuinely converted--and then come down doubly hard on those who live only half as carelessly as the repentant ones did before they got caught or saw the light?

We've visited this theme before. Do we learn more from the old-left American Stalinists of the '30s, who later turned far right in their attacks on anyone who was just a little bit socialist, than from those who were smart enough never to have fallen for communism? Do we profit more from those who got fingers and souls burned by overidentification with the New Left of the '60s but who now profit on Wall Street or join the New Right's excoriation of the moderate left of years ago, than from those judicious enough to have made their political case without extremism then or now?

On the sexual front: when Malcolm Muggeridge, a hell-raiser for decades until his libido slowed down, turned to Jesus and became more severe than Jesus ever was in attacking those whose lust level never rose beyond that confessed by Jimmy Carter, should we pay more attention to him than we do to someone who practices sexual restraint throughout his or her life?

Of course, we cherish conversion. The great religious heroes, many of whom were mixed up throughout their lives, are our great teachers. We should hesitate to level charges of hypocrisy against those who indulged in youthful indiscretions and then changed. It is true that someone who comes back from the flames of communism, sexual irresponsibility or hell-raising gains a certain kind of credentials. And they do not have to shut up.

But must we license them as our better teachers? No. The witness of someone who, from his or her nursery years through the pathways of temptation, consistently makes pilgrim's progress also deserves the right to the title Best Teacher. Now, let's all forgive Dr. Laura.