Abortion: What Philosophers Argue About

Here’s a strange thing about arguments over abortion. Two people can agree on almost all the facts—they can agree when a fetus develops a heartbeat, when it can feel pain, when it could survive outside the womb—and still disagree completely about whether abortion is morally wrong. That’s because the disagreement isn’t really about biology. It’s about a handful of deep, slippery questions: What makes a being count, morally? When is killing justified? And what does it mean to have a “right to life” in the first place? Philosophers have been arguing about these questions for decades, and nobody has settled them. But the arguments themselves are fascinating—partly because they force you to think about what you really believe, and partly because they show how hard it is to be consistent.

The Basic Argument Against Abortion

Let’s start with the most straightforward argument you could give for why abortion is wrong. It goes like this:

The fetus is a person.
All persons have a right to life.
So the fetus has a right to life.
It’s morally wrong to kill something that has a right to life.
Abortion kills the fetus.
Therefore, abortion is morally wrong.

This argument has real power. It feels obvious that you shouldn’t kill people, and it feels obvious that a fetus is a human being. But notice something: the word “person” appears twice, and it might mean something different each time. When someone says “the fetus is a person,” they might just mean “the fetus is a human being”—a member of the species Homo sapiens. That’s true, but it doesn’t automatically tell us that the fetus has the same moral status as you or me. When someone says “all persons have a right to life,” they probably mean something like “all beings that count fully, morally, have a right to life.” But that just raises the question: does a fetus count fully, morally?

So the argument has a hidden weak spot. It’s only convincing if you already believe that fetuses have the same moral status as adults. And that’s exactly what’s being argued about. Philosophers call this an “equivocation”—using the same word with two different meanings.

The Violinist: A Famous Thought Experiment

One of the most famous challenges to this argument comes from philosopher Judith Jarvis Thomson, who asked you to imagine something weird. Suppose a famous violinist is dying of kidney disease. You are the only person who can help him—by staying in a hospital bed for nine months, connected to him so your kidneys can filter his blood. You politely decline. Then you wake up in the hospital, attached to the violinist. The Society of Music Lovers has kidnapped you. The doctor tells you that detaching yourself would kill the violinist, and the violinist has a right to life. So you can’t unplug.

Can you? Of course you can, Thomson says. The violinist has a right to life, but that doesn’t mean he has a right to use your body against your will. Even if it’s terrible that he’ll die, you’re allowed to say no to nine months of forced bodily service. Thomson’s point is that even if the fetus has a right to life, it doesn’t automatically follow that abortion is wrong. The woman’s right to control her own body might override the fetus’s right to life.

Now, you might think this only works for pregnancies caused by rape—since in the violinist case you were kidnapped. What about a case where you had consensual sex? Aren’t you responsible for the fetus’s dependence on you? Thomson has an answer for this too. Imagine a slightly different story: you knew the Music Lovers might kidnap you, but you decided to go about your normal life with bodyguards anyway. You were kidnapped anyway. You’re still allowed to unplug, even though your choice to go out was a cause of the situation. Similarly, having sex—especially with contraception—doesn’t mean you’ve given up your right to say no to nine months of pregnancy.

This whole debate gets at a deeper question: what does a right to life actually give you? It doesn’t give you a right to whatever you need to survive. You don’t have a right to George Clooney’s hand on your forehead, even if it would cure you. You don’t have a right to someone else’s kidney. A right to life, Thomson argues, is really just a right not to be killed unjustly. And whether killing a fetus counts as “unjust” is exactly what’s being debated.

Does Potential Matter?

Another argument against abortion goes like this: a fetus has the potential to become a person with a full life. That potential gives it moral status now. But is that true?

Consider another thought experiment, from philosopher Michael Tooley. Imagine a serum that, if injected into a kitten, would turn it into a super-intelligent cat—as smart and emotionally complex as a human adult. The serum takes a while to work. Would it be wrong to inject a neutralizing agent right after the serum, preventing the kitten from becoming super-intelligent? Probably not. But the injected kitten has the potential to become a being with full moral status. If potential alone gave you moral status, it would be wrong to neutralize the serum. Since it doesn’t seem wrong, potential alone isn’t enough.

(Of course, this argument assumes it’s okay to kill kittens. If you think kittens have a right to life, the example won’t work for you. But you could rephrase it: even if kittens have some moral status, they don’t have full moral status. The serum would give them more status. The question is whether having the potential for more status gives you that status now. And the example suggests it doesn’t.)

There’s another way to think about this. Philosopher Elizabeth Harman has suggested that what matters isn’t potential but actual future. A fetus that will grow up to be a person has an actual future as a person. A fetus that will die early doesn’t. On this view, early abortions that prevent a fetus from ever becoming conscious are less morally significant than later abortions of fetuses that would have become people. This is a subtle position: it says that the same fetus, at the same stage of development, might have different moral status depending on whether it’s going to be carried to term. That’s strange, but it might actually match how many people feel—people often love and protect wanted early fetuses in ways they don’t for unwanted ones.

The Argument from Loss

Here’s a clever argument that tries to avoid the whole debate about whether fetuses are persons. It goes like this: what makes killing an adult wrong is that it deprives them of a valuable future—all the experiences, relationships, and projects they would have had. A fetus, if aborted, is deprived of an even longer valuable future. So abortion is wrong for the same reason killing an adult is wrong.

This argument, from philosopher Don Marquis, doesn’t need to claim the fetus is a person. It just needs to claim that what makes killing wrong is the loss of a valuable future—and that fetuses have those futures.

But there are responses. One objector says that what makes killing wrong isn’t just the loss of a future. It’s the loss of a future to someone who cares about having a future. A fetus, especially early on, doesn’t have any desires or plans. It doesn’t have a self that can be deprived. Another objection says that the fetus doesn’t have that future in the same way you do. You are psychologically connected to your future self—you have memories, plans, and intentions that link you to tomorrow and next year. A fetus has none of that. So maybe the fetus isn’t really “deprived” of anything.

The Golden Rule

Here’s another simple argument: The Golden Rule says “treat others as you would want to be treated.” You are glad you weren’t aborted. So you shouldn’t abort others.

But this argument has a problem. The Golden Rule only applies to beings that count morally. You probably don’t think it applies to, say, a cockroach. So the argument sneaks in the assumption that fetuses count morally—which is exactly what’s being argued about. Once you add that assumption, you’re back to the same debate.

What About Intrinsic Value?

Some philosophers argue that the real disagreement isn’t about whether fetuses are persons, but about whether human life has intrinsic value—value in itself, regardless of what anyone thinks about it. On this view, even people who support abortion rights often think something bad happens in an abortion; they just think it’s justified by other considerations. And people who oppose abortion often think abortion is permissible in cases like rape, which would be weird if they thought it was literally murder. (You don’t get to murder an innocent person just because you were raped.)

Ronald Dworkin argued that both sides in the abortion debate actually agree that human life has intrinsic value. They just disagree about how much value it has, and what justifies destroying something with that value. This would mean the two sides aren’t as far apart as they think. But critics point out that this might be too nice—many opponents of abortion really do think it’s murder, and many supporters think early abortion is no big deal at all.

Moral Risk

Here’s a different kind of argument. Suppose you’ve thought about all the arguments and you’re pretty sure abortion is permissible. But you could be wrong. There’s some chance that abortion is seriously wrong. And taking a risk of doing something seriously wrong—when you could avoid it—seems like a bad idea. So even if the arguments against abortion are all bad, the mere fact that smart people disagree gives you a reason to be cautious.

This is called the “argument from moral risk.” Some philosophers think it’s powerful; others think it proves too much. After all, there are smart people who disagree about almost everything—should you avoid driving because someone smart thinks it’s wrong? And some philosophers argue that purely moral uncertainty doesn’t create genuine moral reasons the way factual uncertainty does (like not knowing whether a medicine will save or kill someone).

Choosing Against Disability

Not all arguments about abortion are about whether abortion in general is wrong. Some target specific reasons for abortion. For example, some people abort fetuses that would be born with disabilities. Here’s an argument against that: aborting a wanted pregnancy because the baby would be disabled expresses a terrible attitude—that disabled people shouldn’t exist or are less valuable. Even if abortion in general is fine, this particular reason is wrong.

Defenders of this practice have several responses. First, the parent might be worried about the burden of raising a disabled child, not the value of the child’s life. Second, it’s totally fine to prevent disability—you take folic acid to prevent neural tube defects, and nobody says that’s expressing a bad attitude. So why is it different to avoid having a disabled child through abortion? Third, you can think a disability would make life harder without thinking disabled people are less valuable. That’s a real difference.

Why All This Matters

You might think this whole debate is just academic—interesting to argue about but not affecting real life. But think about what’s at stake. If abortion is murder, then millions of killings are happening every year, and we should do everything possible to stop them. If abortion is permissible, then restricting access to it forces people to remain pregnant against their will, which means forcing them to go through childbirth (which is dangerous and painful) and often forcing them into parenthood.

Thomson’s violinist argument focuses on the burdens of pregnancy. But many philosophers think the real issue is motherhood. A person who wants an abortion doesn’t just want to avoid nine months of pregnancy. They want to avoid becoming a parent to a new child—a responsibility that lasts a lifetime. Making an adoption plan doesn’t solve this, because many people bond with their fetus during pregnancy and can’t bear to give up their own child. So restricting abortion doesn’t just force people to be pregnant; it often forces them to become mothers when they’re not ready.

The arguments in this article don’t settle anything. But they show you something important: the abortion debate isn’t a simple clash between “people who care about life” and “people who care about freedom.” It’s a tangle of deep questions about what counts as a person, what rights really mean, and what we owe to beings that can’t speak for themselves. Philosophers have made those questions sharper and stranger than you might expect. And they’re still arguing.

Key Terms

Term	What it does in the debate
Right to life	A moral claim that a being cannot be killed; the central concept in arguments against abortion
Equivocation	Using the same word with two different meanings, which can make a bad argument look good
Potentiality	The idea that what something could become gives it moral status now
Actual Future Principle	The view that a fetus matters morally because it will become a person, not because it could
Intrinsic value	Value something has in itself, not just because someone wants or uses it
Moral risk	The idea that uncertainty about whether something is wrong gives you a reason not to do it

Key People

Judith Jarvis Thomson – A philosopher who invented the violinist thought experiment to argue that even if fetuses have a right to life, abortion can still be justified.
Don Marquis – A philosopher who argued that abortion is wrong because it deprives the fetus of a valuable future—without needing to claim the fetus is a person.
Michael Tooley – A philosopher who used the kitten serum thought experiment to argue that potential alone doesn’t give moral status.
Ronald Dworkin – A philosopher who argued that both sides in the abortion debate actually agree that human life has intrinsic value; they just disagree about what justifies destroying it.

Things to Think About

The violinist case depends on pregnancy being a burden. But what if someone has an easy pregnancy with no complications? Does that change whether they’re allowed to unplug from the violinist?
If potential alone doesn’t give moral status, at what point does a fetus start to matter morally? At consciousness? At sentience (ability to feel pain)? At the ability to survive outside the womb? How would you even figure this out?
The Golden Rule argument seems simple, but it might prove too much. If you’re glad you weren’t aborted, does consistency require you to think abortion is always wrong? Or could you consistently say “I’m glad I wasn’t aborted” while supporting others’ right to choose?
If you knew that a fetus would grow up to be a horrible person—a dictator who causes millions of deaths—would that change whether abortion is permissible? Does the content of the future matter, or just the fact that there is a future?

Where This Shows Up

Politics and law: The abortion debate shapes elections, Supreme Court nominations, and laws in nearly every country. The arguments philosophers make show up in court opinions and political speeches.
Medicine: Doctors and patients face these questions in real time when making decisions about pregnancy, especially when the fetus has severe abnormalities or the pregnancy threatens the mother’s health.
Everyday conversation: You’ve probably heard someone say “I’m personally opposed, but I think it should be legal” — that’s a philosophical position about the difference between what’s wrong and what should be illegal.
Other moral debates: Similar questions about personhood, potential, and rights come up in debates about animal ethics, euthanasia, and artificial intelligence. If a computer became conscious, would it have a right to life? The arguments about abortion have already done some of the work.