This is one of those philosophical arguments that routinely stuns me. Like the stem cell arguments that certainly go hand-in-hand with it. Amid all the debate about stem cell research, I only recently found out that the "embryo" these cells are taken from consist of only about 150 cells. That's right. It's a blastula, a little sphere of cells. No arms, no legs, no head. The fertilized egg has only divided about 8 times. But once you posit a soul from the moment of conception, anything done to the little darling is torture and murder. The following is from Frozen Embryo = Person? and is plenty scary for the future.

Earlier this month, Illinois judge Jeffrey Lawrence refused to dismiss a wrongful death suit against a fertility clinic in Chicago. The plaintiffs are a couple, Alison Miller and Todd Parrish. They allege that the defendant, the Center for Human Reproduction in Chicago, discarded their nine embryos and thereby ended the embryos' lives.

In Illinois, the judge explained, a fetus qualifies as a deceased person for purposes of the Wrongful Death Act. Furthermore, said the judge, "a pre-embryo is a 'human being' ... whether or not it is implanted in its mother's womb." For this conclusion, the judge cited another Illinois law that specifically finds that an "unborn child is a human being from the time of conception and is, therefore, a legal person."

Critics of the decision worry about its potential implications for the right to abortion, for stem cell research and for fertility medicine. These worries may or may not turn out to be warranted.

But the decision deeming a fertilized egg a person has moral and legal implications for other issues. It also asks whether, prior to a baby's birth, property law takes sufficient account of the various interests at stake in abortion and fertility medicine (the latter of which includes stem-cell research).

One argument for the right to abortion is that until viability (or birth, quickening, or whatever the chosen line may be), there is no "person" and therefore no one whose life is entitled to legal protection. If Jane Doe destroys a living entity that does not qualify as a person, then Ms. Doe need not worry about the criminal or civil sanctions that would accompany the destruction of a person. If, on the other hand, a fetus (or even an embryo) is a person, then Jane (and the medical personnel who assist her) might need to worry about homicide liability following an abortion.

Similarly, fertility medicine – like the law of abortion, as currently developed – proceeds on the assumption that embryos are not persons. For that reason, women may undergo ovarian hyper-stimulation to produce many eggs which will be fertilized to produce many more embryos than she would be willing or able to carry to term as pregnancies. A large number of these embryos will eventually be destroyed. If embryos qualify as persons under the law, then such destruction constitutes murder. Moreover, the deliberate creation of persons with the knowledge of their future destruction would make any participant an accomplice.