With the nomination of Samuel Alito LAW ’75 to the Supreme Court and a challenge to Roe v. Wade inevitable, it’s time to retire some bad arguments and adjust the framework in which we discuss abortion.

Opponents tend to emphasize the fetus’s right to life, while supporters emphasize the mother’s right to control what happens to her body, as if a clear articulation of either is enough to determine abortion’s moral, let alone legal, permissibility. Each side’s claim would have merit without reference to the abortion dispute. If a human fetus were, say, growing in a cabbage patch and its growth cost nothing to anyone, we would agree it has the right not to be killed, and furthermore, to receive everything it needs to live. If a woman contracts a tapeworm, on the other hand, no one doubts her right to remove the parasite, because so long as no one is harmed, she has the right to decide what lives in her body. Both sides, then, ought to discuss abortion’s permissibility as a question of competing rights, not as a question of simply establishing one right on behalf of the fetus or the mother.

Of course, opponents might be willing to admit that abortion is a question of competing rights, only to claim a fetus’s right to life trumps any the mother might have.

Specifically, they argue that an embryo is a human being, so abortion constitutes murder … or, even if an embryo is not a human being at conception, it’s impossible to determine when it becomes one. Better to play it safe and call a fetus a human being at the earliest conceivable opportunity (pun intended). This is a “slippery slope” argument.

As philosopher Judith Thomson demonstrated, the fact that a fetus is a human being does not automatically mean abortion is wrong. The fetus’s right to life, she proposes, consists not in its right to receive whatever it needs to live but rather in its right not to be killed in an active, “unjust” way. There’s something to her reasoning, but it can be extended to absurdity. Isn’t it true that a three-week-old, or even a three year old baby, also makes demands on a woman’s body? Does that give the mother the right to cast the baby out?

I think not.

Thomson wanted to avoid the messy debate over when a fetus can be called a human being, but supporters of abortion must actually address the embryo-is-a-human argument and the danger-of-drawing-a-line argument. As it turns out, both are flawed.

The argument that an embryo is a human being rests on a bit of linguistic and moral legerdemain. It conflates two separate concepts: life and personhood.

An embryo is a life — it is a changing, self-replicating ball of cells that undergoes metabolic processes. But is this all it takes to be a person?

Certainly we consider our personhood to be predicated on more than the mechanics of biology. We are people not because we are a conglomeration of replicating cells, but because we have thoughts, emotions, identities etc.

Personhood inheres in our mental activity.

Now, I understand that trying to determine personhood is a dangerous game, but we can avoid the slippery slope by saying that an embryo with no brain or mental activity could not possibly be a person, and leaving it at that. Nor does it matter (at least here) that a human embryo will eventually develop a brain and mental activity. You wouldn’t call an acorn an oak tree, and neither should you call an embryo without distinguishing human features a human. Thus we have a prescription for a totally safe line vis-a-vis morality, and probably legality, on abortion.

Allow it before (but only before) fetal brain development begins. Under such guidelines, abortion does still entail killing, but doesn’t entail or even risk the murder of a person.

Still, opponents of abortion tend to argue a human embryo is special, with full human rights. Though they lump this claim in with the “embryo-is-a-human” argument, I suspect many would support the claim on its own. In what, though, does an embryo’s humanity consist? If you claim it consists in something extraphysical, I cannot dispute you with logic. Such super-scientific or religious reasoning, however, has no place in our courts.

If, on the other hand, you claim an embryo’s humanness consists in something physical, you have nothing left to point to but its DNA. It’s true an embryo’s human DNA is different from any other DNA, but uniqueness alone does not confer special status. A cabbage plant also has unique DNA. A human embryo’s DNA can only be said to be special because that DNA will eventually let the embryo think, feel, create art etc. Certainly it is possible to call the destruction of this embryo, this human-in-potentia, a bad thing, but we should clarify the nature of the crime. Aborting it would be closer to destroying the blueprints of a particularly beautiful building than destroying the building itself, or murdering a person. In order to call abortion morally impermissible (putting aside the legal question for a moment), you must claim that the wrongness of destroying these blueprints overbalances the right done to the mother.

I have not attempted to show that Roe v. Wade was correct, or that abortion should be legal or morally acceptable. I have only sought to counter claims that an embryo is a human being at conception and that designating an embryo as such is the only “safe” way to draw the human-non-human boundary line.

Other lines, I would suggest, may be equally safe, yet more amenable to the mother’s rights.

David Busis is a senior in Timothy Dwight College.