One of the most famous thought experiments in ethics is Judith Jarvis Thomson’s violinist thought experiment, from her article “A Defense of Abortion”. The statement of the thought experiment is reproduced below:

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 is now 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?

The thought experiment is famous for how well it seems to provide evidence in favor of the ethical permissibility of abortion.

However, thought experiments, as convincing and well-crafted as they may be, can still be critiqued in much the same way a physical experiment can be– perhaps the set up of the thought experiment or the conclusions drawn from it were faulty.

And it appears that there in fact is something at least potentially problematic about Thomson’s thought experiment. Specifically, the potential issue is that it directs the reader’s focus to aspects of the scenario either not relevant to the subject or potentially biasing. Two particular examples of this can readily be named:

(1) Why a Violinist?

The very idea behind Thomas making such a point to mention that this person you find yourself attached to is a violinist remains somewhat mysterious. We are told that he’s a very famous violinist… and… so what? The thought experiment could very well conceivably be run without the inclusion of this information.

If anything, the focus on the fact that he is a violinist might cause the reader take that aspect of the person into consideration when they weigh the ethical options, but it seems that we would be dealing with just too many variables at this point. Does the moral value of a person depend on their occupation, or fame, or value to society? This question may be important, but not it’s not clearly relevant to the essential question at hand.

And so the worry is that the reader will get too distracted taking this relatively minor detail into account. Would the results of our experiment change if this was a genius cancer researcher…?

The point here is that his occupation should perhaps not even be mentioned, and that it might be best to focus on the most general case– the case where we are just dealing with a human life.

(2) Why Did You Kidnap Me?

The other potentially problematic aspect of the thought experiment is the fact that we find ourselves kidnapped and must now make a decision in light of this injustice. This is problematic because it can be argued that the fact that the reader finds themselves kidnapped— subjected to some kind of injustice at the hands of this “Society of Music Lovers”– might already prime the reader to view the scenario with a kind of contempt or to view it in a way that puts the situation already in an unnecessarily unfavorable light.

Clearly, the idea of finding oneself stuck to some person and faced with the choice of either killing them or being stuck to him/her for some length of time could never really be viewed in an especially favorable light, but it is unclear why this extra layer of misfortune and injustice need be included.

An Alternative, or Even a Counter Thought Experiment

Consider the following thought experiment:

A strange phenomenon has been observed where some people, all of a sudden and apparently at random, wake up finding their bodies attached to the body of some other apparently random person. You wake up one morning and find yourself in this situation– some person, who is at present still asleep*, has mysteriously stuck to your body. It has been noted that it takes approximately nine months for two people attached to each other in this way to be able to separate. However, you do have a way of detaching your body from theirs, but it would mean that the other person dies. Do you detach yourself?

[*It might be more effective to say that this other person so happens to be unconscious, or in some other state where there is no risk of them waking up and potentially retaliating.]

From the results of the above discussion, it would appear that this thought experiment would be more effective at testing the relevant concepts, as it appears to avoid the inclusion of any extraneous information. While it may be less colorful than Thomson’s, it is less clear that there is anything particularly wrong with it.

It might be critiqued that this thought experiment does not allow for the situation to be extreme enough to really work intuitions on to what degree others have the right to one’s body (if at all others have such rights)– should it be made that in this revised experiment, that attached persons are bedridden for the duration of the nine months? It could very well be made so– and it might still function as a counter thought experiment in the sense that it might lead to a different weighing of the other person’s right to life vis a vis one’s right to their own body.