This piece originally appeared on Abort73.com and was written by Michael Spielman.

Last week, I received an email query that is worth sharing. It comes from a young woman who says she believes abortion is murder but came across an online argument for abortion that she had a hard time refuting.

She writes, “I don’t agree with everything this person said, but some of their arguments make sense.”  She copied and pasted the argument and asked how we would respond.

Here it is (with some minor grammatical edits for clarity):

If my younger sister was in a car accident and desperately needed a blood transfusion to live, and I was the only person on Earth who could donate blood to save her, no one can force me to give blood—even though donating blood is a relatively easy, safe, and quick procedure. Even to save the life of a fully-grown person, it would be illegal to force me to donate blood if I didn’t want to.

See, we have this concept called “bodily autonomy.” It’s this cultural notion that a person’s control over their own body is above all and must not be infringed upon. We can’t even take life saving organs from corpses unless the person gave consent before their death. Even corpses get bodily autonomy.

To tell people that they must sacrifice their bodily autonomy for nine months against their will in an incredibly expensive, invasive, difficult process—to save what you view as another life is desperately unethical. You’re asking people who can become pregnant to accept less bodily autonomy than we grant to dead bodies.

Conceptually, this argument bears similarities to a famous abortion analogy that was penned decades ago by Judith Jarvis. We deal with that argument at some length on our “Competing Rights” page. It’s worth considering if you’re not familiar with the argument—or how to respond to it.

Regarding the specifics of the analogy that was shared in the email, I would immediately object to the use of sister instead of daughter. Framing the relationship this way is misleading because we are not morally obligated to siblings in the same way that we are to our children.

Here’s what I mean. I am not legally responsible to provide food, clothing, shelter, education or medical provision for my little sister, but I am legally obligated to provide these things for my daughter—at least until she comes of age.

The question then becomes, if I was the only person on Earth who could save my daughter’s life by donating blood, would I be legally obligated to do so? That’s a difficult question. Here’s an excerpt from a leading white paper on the ethics of parental decision making from the University of Washington School of Medicine:

Medical caretakers have an ethical and legal duty to advocate for the best interests of the child when parental decisions are potentially dangerous to the child’s health, imprudent, neglectful, or abusive. As a general rule, medical caretakers and others should challenge parental decisions when those decisions place the child at significant risk of serious harm. When satisfactory resolution cannot be attained through respectful discussion and ethics consultation, seeking involvement of a State child protection agency or a court order might be necessary.

In this country, parents have a legal responsibility to provide adequate medical care for their children—whether they want to or not. When they fail to do so, child protection agencies get involved.

Does parental responsibility extend to something like giving blood for a child whose life is in danger? If we were to do a survey, I suspect virtually everyone would say that in these circumstances, yes, the parent has a moral obligation to give blood for their child.

But does moral responsibility translate to a legally-binding requirement? That’s a bit trickier. If donating blood would save my child’s life, and I refused to do so, I imagine the supervising physician would pursue a court intervention. The court regularly rules that parents must give of their money to support their child.

Would it be any less reasonable for the court to rule that a parent must give of their blood to save their child?

This is all admittedly speculative because—to my knowledge—a case like this has never arisen. The scenario required for this argument to work is entirely hypothetical. In the real world, the pool of available donors is not limited to a single person. At the very least, a person who refused to give blood for their dying, minor child would be deemed an awful, unfit parent—even if the law couldn’t force them to give blood.

Is that really the standard we want to use for justifying abortion?

If you’re familiar with the movie Up, the relationship between the old man, Mr. Fredrickson, and the young boy, Russell, is a remarkably strong argument against the position being advocated by the example that was shared in the email—and I’m indebted to Stephen Wagner (via Scott Klusendorf) for first noticing the connection.

The giving blood analogy is designed to illustrate that one person is not morally bound to care for another. Am I my brother’s keeper? But think about that premise in the context of Up.

Mr. Fredrickson airlifts his entire house out of the congested city he lives in because he’s sick and tired of people. He just wants to be left alone. But shortly after his departure, there is an extremely disconcerting knock on his front door.

It’s Russell, a neighborhood boy who Mr. Fredrickson can’t seem to get rid of—despite his best efforts to do so. Russell was hiding under the porch when the house took off, and now he’s clinging to that same porch thousands of feet off the ground.

At that moment, what is Mr. Fredrickson’s moral responsibility to this boy who has been nothing but a nuisance to him? Would there be anything wrong with leaving Russell out there to die? After all, Mr. Fredrickson never consented to his being there and is not the boy’s guardian.

Would Planned Parenthood say that it was within Mr. Fredrickson’s rights to let Russell die?

Of course, in the context of abortion, children aren’t simply left alone to die. Children are violently killed and forcibly removed. It would be more akin to Mr. Fredrickson taking his walker and beating Russell to a bloody pulp until he finally fell from the porch.

Would Mr. Fredrickson really have been within his legal rights as a private, autonomous citizen to refuse taking Russell in or to force him off his private property?

Like the giving blood scenario, the Up analogy is completely hypothetical. There is nothing normative about it, but it helps demonstrate that our moral compass does expect people to care for and protect vulnerable children—even when doing so is extremely inconvenient.

And while both stories rely on contrived scenarios that don’t happen in real life, pregnancy itself is the most normal and natural relationship in the world. Unless the sex was not consensual, it’s inaccurate to say that pregnancy is something that is forced upon women.

As always, the real question is ever the same. Are unborn children morally equivalent to born children?

Is pushing Russell off the porch the same thing as vacuuming a human child out of the womb? The author of the giving blood example argues that the law never demands that one human being use their body to sustain another—and for good measure implies that the question of when life begins is open to debate anyway. It isn’t.

If it is reasonable to demand that parents care for their born children, isn’t it also reasonable to demand that they care for their unborn children? And if it is reasonable to legally prohibit parents from killing their born children, isn’t it also reasonable to legally prohibit parents from killing their unborn children?