The Principle of Analogy
- Noonan's Argument
- Noonan's First Premise
- Noonan's Third Premise
- Thomson's Variation
- Thomson's Argument
- The Extreme View
- The Second Variation
- The Third Variation
- The Fourth Variation
Today we revisited and illustrated the astonishingly powerful Principle of (Moral) Analogy by considering Thomson's significant contributions to the abortion debate. Our interest in the debate was not particularly about abortion per se; rather, we were focused on Thomson's deft and repeated use of the Principle of (Moral) Analogy to shed light on the debate.
Thomson sets aside the question of whether or not a human conceptus is a human being by simply assuming that, indeed, the human conceptus is a human being or, as she puts it, a fetus is a person. Debates over abortion are ordinarily thought to hinge on the status of the fetus. If it's a person, then it is usually thought that the argument against abortion is sound. The step from "a fetus is a person" to "abortion is morally wrong" is usually taken for granted.
As Thomson points out, the step to showing that abortion is morally wrong from the assumption that a fetus is a person is by no means obvious or straightforward. Thomson shows this by appeal to the Principle of Analogy in the Case of the Famous Unconscious Violinist. If Thomson is correct, it is morally permissible for you to unhook yourself from the Violinist and thereby let the Violinist die. But if that's the case, then there is something wrong with the argument which concludes that it is morally wrong for a woman to abort a pregnancy due to rape. In particular, since it has a false conclusion and is valid, it must have a false premise.
Specifically, Thomson uses the Case of the Famous Unconscious Violinist to argue that it is false that the fetus' right to life outweighs the mother's right to determine what happens in and to her body. But is it generally false, or is it only false in cases of pregnancy due to rape? Surely there are a number of variations on the basic abortion argument. That is to say, by granting for the sake of argument that the fetus is a person Thomson correctly teaches us that it does not thereby follow that abortion is morally wrong. But the task of showing that the proposition,
If the fetus is a person, then abortion is morally impermissible,
is false requires an astonishingly intricate and complicated argument.
By way of discussing Thomson's argument, let us briefly consider each step in turn.
Thomson opens by explaining that it is no straightforward matter to get from the premise that the fetus is a person to the moral impermissibility of abortion. What is required is an additional assumption like
P1: A fetus' right to life is more stringent than a mother's right to determine what happens in and to her body.
But this assumption is clearly false. To show that it is false, Thomson constructs the Case of the Famous Unconscious Violinist. Using the Principle of (Moral) Analogy, Thomson is able to show that if we think intuitively, as most do, that it would be perfectly morally permissible for one to disconnect oneself from the Famous Unconscious Violinist, then we should think that it is morally permissible for a woman pregnant due to rape to get an abortion. But then the conclusion to Thomson's variation on Noonan's argument is false, which implies that the above assumption must be false since the argument is valid and every other premise is either true or granted for the sake of argument. This, note, is a style of argument that Thomson will employ repeatedly.
Thomson considers a number of variations on the basic argument. Each variation is designed to show that abortion is morally wrong. Keep in mind that these are not Thomson's arguments in the sense that she is trying to get us to believe their conclusions. Rather, these are arguments which she has presented for purposes of criticism. She wants to show us that these arguments are unsound. (Except, of course, for the last one. But we will get to that shortly.)
Thomson calls the next variation the Extreme View, since it supposes that
P2: No being with a right to life may be killed.
To understand why someone might think it the case that no being with a right to life may be killed, Thomson gives four distinct arguments which conclude that no being with a right to life may be killed. She thinks, of course, that each of these arguments is unsound, just as she thinks that the conclusion that no being with a right to life may be killed is demonstrably false. To see that it is false that no being with a right to life may be killed, Thomson first extends the Case of the Famous Unconscious Violinist by asking, what if you were told by the attending physician that being hooked up to the violinist will kill you? Surely in such a case, even though the violinist presumably has a right to life and is perfectly innocent, it would be morally licit for one to disconnect oneself (strictly as a matter, you should realize, of self-defense.)
The justification of self-defense is more clearly brought to bear in the Case of the Rapidly Growing Baby in the Tiny House. What this case shows is that it is simply false that no being with a right to life may be killed, since self-defense can be counted as an over-riding consideration. That is to say, in a case of your life or someone else's life (even through no fault of the other person's) it is morally permissible for you to defend yourself. Thus, in such cases, beings with a right to life may be killed.
Indeed, under the assumption that the fetus is a person, we found that abortion is permissible in the vast majority of cases: cases where the pregnant woman's life is endangered, cases where the pregnancy was due to rape, cases where contraception failed, and, perhaps (!), cases where pregnancy results from having unprotected sex while in a state of diminished capacity - while drunk, for instance. The conclusion was if the fetus is a person, then abortion is morally permissible in all cases except, possibly, those cases where the mother has explicitly assumed a special responsibility for the life of the fetus, as in cases where the mother intentionally becomes pregnant. This, note, is a profound result which does not at all concur with the intuitions of those who appear to think that if the fetus is a person, then abortion is clearly morally impermissible.
The important take-away from this are the many examples of the skilled application of the Principle of (Moral) Analogy. Viz.,
- The Case of the Famous Unconscious Violinist
- The Case of the Rapidly Growing Infant in the Tiny House
- The Lone Coat Thought Experiment
- The People-Seed Thought Experiment