I

Analogies are the stuff out of which normative moral philosophy is made. They shed new light on old problems, they reveal the importance of aspects of situations that otherwise remain hidden or obscure, and they have the power to change one's view of the world. It is true that students of moral philosophy learn primarily the structure and texture of prominent moral theories, but the one thing students are trained to do is to generate analogies and examples designed to illustrate and test the moral theories they've learned.

Certainly one of the most famous analogies constructed by a philosopher in order to argue for a specific controversial moral conclusion is the one involving Judith Thomson's unconscious violinist.¹ Reflection upon this analogy is meant to show us that abortion is generally not immoral even if the prenatal have the same basic moral status as the postnatal. This was and still is a controversial conclusion, and yet the analogy does seem to reveal in a very vivid way what makes abortion a reasonable response to a terrible situation.

Thomson's analogy has been attacked from all sides. Some argue that the analogy does not lead to the conclusion Thomson claims it does. More common is the argument that the story of the violinist is just not analogous to pregnancy and abortion. I have no interest in kicking a dying horse here. Rather, I want to create a new horse—stronger, faster, better. That is, I want to develop an analogy that sheds light on the issue with which Thomson was concerned while avoiding the most serious objections that the analogy originally drew. I want to take something constructive from the debate between Thomson and her critics.

So first I will re-present Thomson's violinist analogy, and then summarise the main flaws of the analogy her critics have identified. Then I will offer a different analogy, one that I hope is free of the flaws of the original, but which nevertheless sheds light on the question of the morality of abortion.

II

Here is Thomson's analogy, in her own words:

“You wake up in the morning and find yourself back to back in bed with an unconscious violinist. A famous unconscious violinist. He has been found to have a fatal kidney ailment, and the Society of Music Lovers has canvassed all the available medical records and found that you alone have the right blood type to help. They have therefore kidnapped you, and last night the violinist's circulatory system was plugged into yours, so that your kidneys can be used to extract poisons from his blood as well as your own. The director of the hospital now tells you, ‘Look, we're sorry the Society of Music Lovers did this to you—we would never have permitted it if we had known. But still, they did it, and the violinist now is plugged into you. To unplug you would be to kill him. But never mind, it's only for nine months. By then he will have recovered from his ailment, and can safely be unplugged from you’.

“Is it morally incumbent on you to accede to this situation? No doubt it would be very nice of you if you did, a great kindness. But do you have to accede to it? What if it were not nine months, but nine years? Or longer still? What if the director of the hospital says: ‘Tough luck, I agree, but you've now got to stay in bed, with the violinist plugged into you, for the rest of your life. Because remember this. All persons have a right to life, and violinists are persons. Granted you have a right to decide what happens in and to your body, but a person's right to life outweighs your right to decide what happens in and to your body. So you cannot ever be unplugged from him.’ “I imagine you would regard this as outrageous . . .”²

And so it is outrageous. It wouldn't be morally incumbent on you to refrain from unplugging yourself from the unconscious violinist. At least I want to presume so.

Even so, the story of the unconscious violinist shows that abortion isn't wrong only if the two situations are analogous. And many have argued that they are not.

There are four aspects of Thomson's story that have drawn such criticism: 1) the issue of consent; 2) the familial relation between the parties in question; 3) the artificiality of the example, and 4) the distinction between killing and letting die. Let me briefly recount each in turn.

CONSENT

In Thomson's story, you did not agree to be hooked up to the violinist. Nor did you in any way act negligently. Rather, you were kidnapped. You were the victim. But it is widely thought that, in most cases, pregnant women bear some responsibility for their pregnancy. If she knows the facts of life, and if the sex was consensual, then a woman's responsibility for the resulting pregnancy seems different from your responsibility in the case of the unconscious violinist. Since you aren't responsible for the fact that the violinist is dependent upon you, you may disconnect yourself. But this does not imply that you may disconnect yourself in a situation where you do bear some responsibility for the fact that somebody needs your bodily organs. We would need some additional argument to reach that conclusion.

FAMILIAL RELATION

It is widely thought both that you have duties to members of your family that you do not have to strangers, and that your duties to your family are stronger than those to strangers. In Thomson's story, the person to whom you are attached is a complete stranger. But a woman who is pregnant is “attached” to her own son or daughter. So the fact that you may disconnect yourself from a complete stranger does not all by itself imply that a pregnant woman may disconnect herself from her own child. Again, we would need some additional argument to reach that conclusion.

ARTIFICIALITY

The next objection is probably the most difficult of the four to articulate. The story of the unconscious violinist, some argue, is a complete fiction. There is no Society of Music Lovers, there are no famous violinists in need of kidney transplants, and there are no kidnappers forcing others to donate their bodies for the good of another. Or at least such situations are thankfully rare. But the kind of dependency a fetus has on his or her mother is the most normal and natural thing in the world; each of us certainly has been there. So the kind of claim the violinist has on you is quite unlike the kind of claim the fetus has on her or his mother. Related to this is the idea that the fetus is bodily dependent upon the woman in a way that the violinist is not dependent upon you. The violinist can make use of your kidneys only because we have on hand certain technological resources. But the fetus is dependent upon the woman in a much more direct, unmediated way. And this difference in dependency gives the violinist less of a claim on you than the fetus has on his or her mother. Or so it is sometimes argued. I admit I feel the force of the present objection, though I find it hard to articulate to my own satisfaction why I do. Unfortunately, I cannot take up here the huge question about the proper role of the concept of the natural or the normal in ethical thought, and whether it is appropriate to think of pregnancy as normal. Rather, I hope to bypass these controversies entirely by offering an analogy that doesn't even begin to raise these thorny questions.

KILLING AND LETTING DIE

Though there have been a number of prominent academic philosophers who disagree, most people think that it is inherently worse to kill someone than to let someone die. In Thomson's story, you are considering whether you may disconnect yourself from the unconscious violinist. If you do so, he will die from his kidney ailment. You will have allowed him to die. With pregnancy, things are different. Unless she is getting a hyserotomy—an abortion procedure very rarely used—a woman who gets somebody to perform an abortion is getting somebody to kill someone. And so the fact that you may allow the violinist die of his kidney ailment does not imply that you may get an abortion.

While these are a few of the more prominent objections Thomson's detractors have raised, it would be remiss of me not to note that Thomson also has able defenders, arguing that the story of the unconscious violinist is indeed analogous to pregnancy after all. But I myself don't think Thomson's original argument can be successfully resurrected, and so now I turn to a different way of doing what Thomson was aiming at.

III

Despite its flaws, we should keep in mind what Thomson was trying to do with the violinist analogy. Our views about fractious moral issues tend to be clouded by self interest, inertia, a lack of empathy, defensiveness, and caricature. By forcing us to consider a situation that in some ways had nothing to with abortion, Thomson was trying to dispel some of these clouds, enabling us to see things as they really are.

We need an analogy that helps us figure out whether abortion is permissible even if the prenatal have the same moral status as the postnatal. To do this, we need an analogy free of the flaws Thomson's is charged with, one in which two individuals are related such that one is bodily dependent upon another, that this dependence is natural rather than artificial, that this dependence arises because of the actions of one of the individuals, and that severing this dependence involves not merely allowing one to die, but killing. If we were to have such an analogy before us, we could consult our intuitions about the morality of severing the two individuals, thereby enabling us to see better the problem of abortion for what it really is.

Fortunately, we can come very close to constructing just such an analogy. For there are individuals—individuals other than the pregnant woman and the fetus she carries—who are naturally asymmetrically bodily dependent, and unable to be severed without killing one of them. We call them conjoined twins. And we can approach the difficult moral question of abortion more fruitfully and more honestly by thinking about whether one conjoined twin may kill her twin sister in order to lead a better life.

Imagine, then, two conjoined twins, Catherine and Elizabeth. Since, like Thomson, we are assuming for the sake of argument that a human being's moral status does not depend upon her age, we may imagine that Catherine and Elizabeth are young adults. Let us suppose that they share vital internal organs. A surgeon could separate them, but because their bodies are asymmetrically related, doing so would enable only Elizabeth to live. That is, Catherine would certainly die if the two were separated.

What may Elizabeth do? May she hire a surgeon to separate them? It may seem that so long as Catherine consents to the operation, Elizabeth may. But since we are trying to model pregnancy, we must structure our analogy differently. Instead, we should presume that Catherine is unable to give or withhold consent to the operation.

Suppose, then, that Catherine falls into a coma, and the doctors confidently surmise that she will remain unconscious for about nine months. But the doctors also inform Elizabeth of a new surgical procedure that would enable her to lead a normal life unattached from Catherine. The downside of the operation, of course, is that Catherine would surely die from the operation. After all, with only one set of vital organs between them, only one can go solo. Let us further suppose that Catherine and Elizabeth never seriously discussed what they would do were such a surgical procedure to be developed. Thus Elizabeth does not know whether Catherine would be willing to sacrifice her life in order for Elizabeth to lead a normal life.

Let us briefly enumerate just a few of the many benefits Elizabeth could expect to incur from the surgery. Her present career options are, to put it mildly, limited. A world of job opportunities would open up were she to be free of her sister. The fact that she is conjoined also puts a damper on her romantic prospects. Most potential suitors aren't interested in a woman conjoined to a sister—much less a sister in a coma—and Catherine rightly worries about the motivations of those who are now interested in her given her present condition. More importantly, she has serious concerns about her own mental health—being attached to someone you'd rather not see every day takes it toll.

Nevertheless, Elizabeth is not a stranger to Catherine; they are family. Perhaps she wouldn't have any obligations to a perfect stranger to whom she were attached, but Catherine is her own flesh and blood. We should also register the fact that the nature of the connection between Catherine and Elizabeth is, while highly uncommon, not artificial. No one deliberately foisted this situation upon them. Nor is it a piece of science fiction; there really are twins conjoined just like Catherine and Elizabeth. Further, the nature of the connection between them is such that to separate them is to kill Catherine, not merely to let her die. It would be sophistry to describe ripping out Catherine's vital organs as allowing her to die.

On the other hand, Elizabeth didn't ask to be attached to her sister, but that is the hand nature dealt her. She is in no way responsible for Catherine's need for her. So the analogy of the conjoined twins suffers from one of the flaws also had by Thomson's unconscious violinist analogy. Neither Elizabeth nor the kidnapped person in Thomson's analogy is responsible for the situation she is in, while, in most cases, a woman who is pregnant seems to be partially responsible for the situation she is in. And this means that even if it is okay for Elizabeth to have the surgery, it still may not be okay to have an abortion.

Now, I see no way of rectifying this analogy to blunt this objection without introducing a gross artificiality into the example. Thus I think it is best we consider our constructed analogy to be comparable only to pregnancies arising from nonconsensual sex.

So what may Elizabeth do? May she get a doctor to perform the surgery even though this means killing Catherine without her consent? Or should she at least wait the nine months until Catherine wakes from her coma, at which time they could discuss the matter? It may be difficult to answer this question definitively without filling in more of the details, but I think I know what the right answer would be.

However, what I think really doesn't matter. Moral philosophers have no special authority when it comes to determining what's right and what's wrong. But they sometimes are able to identify relevant similarities between situations, which is what I've tried to do here.

Furthermore, the whole point of using analogies in moral philosophy is, as stated above, to get us past our self interest, inertia, lack of empathy, lack of imagination and defensiveness. Analogies do this by getting us to look at seemingly all-too-familiar moral problems in a new light. So one really has to look for oneself, and my explaining how things seem to me serves only as a distraction. Thus it is for the reader to decide whether it would be wrong for Elizabeth to have Catherine killed so she can have a better life. Reflection upon this analogy helps to put the moral problem of abortion into clearer perspective—if we are indeed right to assume that the prenatal have the same basic moral status as the postnatal.