"What is it about terminating half a twin pregnancy that seems more controversial than reducing triplets to twins or aborting a single fetus?"

"After all, the math’s the same either way: one fewer fetus. Perhaps it’s because twin reduction (unlike abortion) involves selecting one fetus over another, when either one is equally wanted. Perhaps it’s our culture’s idealized notion of twins as lifelong soul mates, two halves of one whole. Or perhaps it’s because the desire for more choices conflicts with our discomfort about meddling with ever more aspects of reproduction."

This is a long article in the NYT, directed, I think, at readers who support abortion rights generally, but are susceptible to moral doubts about some uses of abortion. I suspect that for those who believe abortion is always immoral — or acceptable only to save the mother from death or severe bodily harm — the destruction of the twin is like every other abortion, and the moral qualms abortion supporters feel is a kind of half-awakening to a problem they should be seeing all the time.

Here's one story:

Shelby Van Voris... and her husband tried for three years to get pregnant, they went to a fertility doctor near their home in Savannah, Ga.... She soon found out she was carrying triplets. Frantic, she yelled at the doctor: “This is not an option for us! I want only one!”

Her fertility specialist referred her to a doctor in Atlanta who did reductions. But when Shelby called, the office manager told her that she would have to pay extra for temporary staff to assist with the procedure, because the regular staff refused to reduce pregnancies below twins. She contacted three more doctors, and in each case was told: not below two. “It was horrible,” she says. “I felt like the pregnancy was a monster, and I just wanted it out, but because we tried for so long, abortion wasn’t an option. My No. 1 priority was to be the best mom I could be, but how was I supposed to juggle two newborns or two screaming infants while my husband was away being shot at [in Iraq]? We don’t have family just sitting around waiting to get called to help me with a baby.”

Eventually, she... flew to New York for the procedure. “I said, ‘You choose whoever is going to be safe and healthy,’ ” she says. “I didn’t give him any other criteria. I didn’t choose gender. None of that was up for grabs, because I had to make it as ethically O.K. for me as I could. But I wanted only one.”

She paid $6,500 for the reduction and [felt] incredibly relieved. “I went out on that street with my mother and jumped up and down saying: ‘I’m pregnant! I’m pregnant!’ And then I went and bought baby clothes for the first time.”

Today, her daughter is 2½ years old. Shelby intends to tell her about the reduction someday, to teach her that women have choices, even if they’re sometimes difficult. “I am the mother of a very demanding toddler,” she says. “I can’t imagine this times two, and not ever knowing if I’d have another person here to help me. This is what I can handle. I’m good with this. But that’s all.”

Picture yourself as that daughter, hearing the story that Van Voris imagines telling in an inspiring fashion. Would you, the daughter, think I am woman, hear me roar, or would you think: There was another me  (2 others) who would have been with me all the times when I was lonely, and my mother killed her (them)? Why?! Because she was afraid we would be too much trouble? Maybe I am too much trouble. But I am trying to be good, and I would have helped take care of my sister(s). My sister(s)! Where are they!

But you anti-abortion readers are perhaps thinking: Why are you getting sentimental about that particular aspect of abortion? Every abortion represents a missing human being.

Here's Ross Douthat's column about the article: "The Failure of Liberal Bioethics."

From embryo experimentation to selective reduction to the eugenic uses of abortion, liberals always promise to draw lines and then never actually manage to draw them. Like [Dr. Mark Evans, described in the article], they find reasons to embrace each new technological leap while promising to resist the next one — and then time passes, science marches on, and they find reasons why the next moral compromise, too, must be accepted for the greater good, or at least tolerated in the name of privacy and choice. You can always count on them to worry, often perceptively, about hypothetical evils, potential slips down the bioethical slope. But they’re either ineffectual or accommodating once an evil actually arrives. Tomorrow, they always say — tomorrow, we’ll draw the line. But tomorrow never comes.