George Tiller, a doctor and abortion provider in Kansas, was shot and killed outside his church on Sunday. The large majority of people on either side of the abortion debate are understandably horrified by an event like this. But it sets up a rhetorical dilemma for anyone who takes seriously the claim that abortion is murder. If George Tiller really was a “baby killer” comparable to Hitler and Stalin, it’s difficult to express unmitigated sadness at his murder. So we get Randall Terry, founder of Operation Rescue, admitting regret — but only that Tiller was a mass murderer who “did not have time to properly prepare his soul to face God.”
On those rare occasions when they attempt to actually talk to each other, people on opposite sides of the abortion debate usually end up talking past each other. Supporters of abortion rights speak in the language of the autonomy of the mother, and her right to control her own body: “If you don’t like abortion, don’t have one.” Opponents of abortion speak in terms of the personhood of the fetus. (Yes, Dr. Seuss’s Horton Hears a Who! — “A person’s a person, no matter how small” — is used to teach this point to Catholic children, over Theodor Geisel’s objections.) Opposition to abortion rights can also be a manifestation of the desire to control women’s sexuality, but let’s concentrate on those whose opposition is grounded in a sincere moral belief that abortion is murder.
If someone believes that abortion really is murder, talk of the reproductive freedom of the mother isn’t going to carry much weight — nobody has the right to murder another person. Supporters of abortion rights don’t say “No, this is one case where murder is completely justified.” Rather, they say “No, the fetus is not a person, so abortion is not murder.” The crucial question (I know, this is not exactly an astonishing new insight) is whether a fetus is really a person.
I have nothing original to add to the debate over when “personhood” begins. But there is something to say about how we decide questions like that. And it takes us directly back to the previous discussion about marriage and fundamental physics. The upshot of which is: how you think about the universe, how you conceptualize the natural world around us, obviously is going to have an enormous impact on how you decide questions like “When does personhood begin?”
In a pre-scientific world, life was — quite understandably — thought of as something intrinsically different from non-life. This view could be taken to different extremes; Plato gave voice to one popular tradition, by claiming that the human soul was a distinct, incorporeal entity that actually occupied a human body. These days we know a lot more than they did back then. Science has taught us that living beings and non-living objects are the same kind of things, deep down; we’re all made of the same chemical elements, and all of our constituents obey the same laws of Nature. Life is complicated, and rich, and fascinating, and not very well understood — but it doesn’t obey separate rules apart from those of the non-living world. Living organisms are just very complicated chemical reactions, not vessels that rely on supernatural essences or mystical élan vital to keep them chugging along. Except “just” is a terribly misleading adverb in this context — living organisms are truly amazing very complicated chemical reactions. Knowing that we are made of the same stuff and obey the same rules as the rest of the universe doesn’t diminish the value or meaning of human life in any way.





One of the notable 
