Here we go again. A religious institution that abhors abortion and exhorts adherents to promote a "culture of life" turns around and pins a scarlet letter on a teenage girl who chooses to continue her pregnancy at the same time it rewards the teenage boy who impregnated her.

But this time, Hester Prynne rewrote the script.

The story comes out of the St. Jude Educational Institute in Montgomery, Ala., where honor student Alysha Cosby was barred from her May 19 graduation, even as the baby's father was allowed to participate.

Rather than acquiesce in her own exclusion, Cosby waited until the last senior had been called up for his diploma. Then she stood up in the audience, announced her own name and walked across the stage.

According to reports in the Montgomery Advertiser and several other papers, this prompted cheers and applause from many of her classmates and other attendees in the church, after which Cosby, her mother and aunt were escorted from the premises by police.

Cosby was told in March that she could no longer attend school, the reports noted, due to "safety concerns" -- even though she had a note from her doctor saying she could safely attend classes for another six months.

Unmoved, school officials told her to complete her class work at home and forget about participating in commencement. A guidance counselor delivered her diploma to her house, and the school did not list her name in the graduation program. It was as if she'd never attended or completed the course work at all.

"I can't believe something like this is happening in 2005," Cosby's mother, Sheila Cosby, was quoted as saying. "I feel like we have regressed instead of progressed. My daughter has been through a lot and I am proud of her. She deserved to walk, and she did."

Just to be clear, religious schools have every right to set standards of behavior for their students based on spiritual and moral values, and if families don't like it, they can always go elsewhere. But when a school applies those standards solely to the girl who cannot hide the evidence while excusing the boy who is equally responsible, something other than morality is at work.

Given the doctor's note, safety doesn't cut it -- unless the administrators see unwed pregnancy as a contagion that might infect the other students. In fairness to the school, that may well have been exactly the fear, that it had to punish Cosby or risk letting loose the germ of permissiveness. But then where was the punishment of her partner? Did someone in the front office suspect a virgin birth?

Absent an explanation from the principal who didn't return my messages, what's left? Only the age-old double standard, misogyny and/or hypocrisy that have a lot more to do with man than they do with God.

Taken together, they put a girl who slips and still tries to do the right thing into an awfully tight and unforgiving box: Don't have sex outside of marriage, but if you do, don't use birth control; and if you get pregnant, you must have the baby because God loves all life. But while you're in the process of producing that which God so loves, don't expect to hang around the rest of us decent folks. And we'd love to explain this further, but we have to go give your boyfriend his diploma.

Somehow, I don't think this is what Jesus would have done if Mary Magdalene had been a high school senior. Then again, I could be wrong.

The point here is not that Cosby's life has been ruined. On the contrary, she finished school, got her diploma and even gained a bit of fame for spitting in the eye of an indefensible double standard. Chances are she's going to be just fine.

No, the real lesson here is for institutions that persist in tarring women and girls for the same sexual behavior they excuse or even reward in boys and men, even as they pay lip service to "family values" and the "culture of life." They can't have it both ways and still claim the moral high ground.

St. Jude may have erased Cosby from its graduation program, but something tells me the school is going to remember her for a long time.