PHIL 2030: Introduction to Ethics
Dr. Robert Lane
Lecture Notes: Wednesday October 15, 2014


[7.] Abortion II: Thomson


Judith Jarvis Thomson is a philosophy professor at MIT.[1]


Her paper, “A Defense of Abortion,” was published in 1971, 18 years before Marquis published his pro-life argument. It is one of the most widely reprinted and discussed papers in ethics.



[7.1.] The “Right to Life” Argument.


Thompson begins by granting that from the moment of conception, a fetus is a person with a right to life.

·         Thomson herself does not believe this. She says that “A newly fertilized ovum, a newly implanted clump of cells, is no more a person than an acorn is an oak tree.” (RTD 88) She is merely granting this point for the sake of argument.

·         She grants this point because she wants to examine what follows from it. In particular, she wants to see whether the claim that a fetus is a person can be used to show that abortion is immoral. She notes that pro-lifers spend most of their time trying to argue that a fetus is a person without then showing that this implies that abortion is wrong:


Opponents of abortion commonly spend most of their time establishing that the fetus is a person and hardly any time explaining the step from there to the impermissibility of abortion. Perhaps they think the step too simple and obvious to require much comment ... I suggest that the step [from the claim that a fetus is a person to the claim that abortion is immoral] is neither easy nor obvious, that it calls for closer examination than it is commonly given, and that when we do give it this closer examination we shall feel inclined to reject it. (RTD 88-89)


Here is the pro-life argument that Thomson has in mind:


The “Right to Life” Argument

1.      A fetus is a person.

2.      All persons have a right to life.

3.      Therefore, all fetuses have a right to life.

4.      The right to life always outweighs the right to decide what happens in one’s own body.

5.      Therefore, a fetus’s right to life always outweighs the mother’s right to decide what happens in her own body.


But is this argument sound?


It is valid:

·         Line 3 follows from lines 1 and 2; if 1 and 2 were true, 3 would have to be true.

·         Line 5 follows from lines 3 and 4; if 3 and 4 were true, 5 would have to be true.


But are all of the premises true?



[7.2.] The Violinist Thought-Experiment.[2]


Thomson argues that it is unsound because premise 4 is false.


To make this argument, she offers the Violinist Thought-Experiment (RTD 89):


Suppose that you wake up one morning and find yourself in a hospital bed, connected by many tubes to another person, who is unconscious. The director of the hospital is there and explains to you that the person sharing your bed is a world-famous violinist. The violinist has a kidney disease and requires the use of someone else’s kidneys to extract toxins from his blood.


So how did you come to be connected to the violinist? The Society of Music Lovers (SML) examined all available medical records and determined that your kidneys are uniquely capable of saving the violinist’s life. So they kidnapped you and connected you in the appropriate ways to the violinist. The hospital director says that she never would have allowed this herself, but the SML people did it on their own and then dropped you off at the hospital. So far as the director is concerned, you are free to disconnect yourself from the violinist and go, but if you do so, the violinist will die. “How long will I have to stay connected to him, in order for him to live?” you ask.


Suppose the doctor says: nine months. Would you then think that it would be wrong to disconnect from the violinist? What if the doctor says nine years? Would it still be wrong to disconnect? What if the doctor says the rest of your life?


At this point, Thomson reasons as follows:


1.      If the right to life always outweighs the right to decide what happens in one’s own body, then it is always immoral to disconnect from the violinist, no matter how long the violinist needs to use your body.

2.      But it is not always immoral to disconnect.

          E.g., it is not immoral to disconnect if he needs nine years, or if needs your entire life.

3.      So, the right to life does not always outweigh the right to decide what happens in one’s own body.


The move from 1 and 2 to 3 is a modus tollens argument, so it is valid (if the premises were true, the conclusion would have to be true).



But are the premises—lines 1 and 2—true?


The real point of debate here is line 2. Do you think it would be moral to disconnect if the violinist needed you to stay connected for nine years? How about for your entire life?



[7.3.] The Violinist Story as an Analogy for Rape.


Because the person in the Violinist Thought Experiment is kidnapped and connected to the violinist against her will, the story might be said to be most similar to pregnancies resulting from rape.[3]


This suggests that, even if a pro-life person is convinced by the Violinist Analogy that abortion is permissible in the case of rape, he could still maintain that it is otherwise immoral.


But Thomson offers a challenge to those who say (a) in general, the Right to Life Argument works to show that abortion is wrong, but (b) abortion is permissible in the case of rape:


Can those who oppose abortion on the ground I mentioned make an exception for a pregnancy due to rape? Certainly. They can say that persons have a right to life only if they didn’t come into existence because of rape; or they can say that all persons have a right to life, but that some have less of a right to life than others, in particular, that those who came into existence because of rape have less. But these statements have a rather unpleasant sound. Surely the question of whether you have a right to life at all, or how much of it you have, shouldn’t turn on the question of whether or not you are the product of a rape. (RTD 90)


In summary, Thompson’s challenge is this:

·         If the Right to Life Argument is sound, it applies to pregnancies that are the result of rape or incest.

·         If abortion is immoral because a fetus is a person with a right to life and because the right to life always outweighs the right to bodily control, then abortion is immoral in the case of rape.



Stopping point for Wednesday October 15. For next time, continue reading Thomson’s article, RTD pp.93-97 (through the end of section 4), and study today’s lecture notes. We could have a pop quiz over both or either at the start of the next class.



[1] Judith Thomson’s website at MIT is: (retrieved October 15, 2014).

[2] For more on thought experiments, see James Robert Brown and Yiftach Fehige, “Thought Experiments,” The Stanford Encyclopedia of Philosophy (Fall 2011 Edition), Edward N. Zalta (ed.), URL = <>.

[3] The majority of abortions performed in the U.S. are not abortions of pregnancies resulting from rape. In 2012, “the American Congress of Obstetricians and Gynecologists (ACOG) released a statement [according to which] ‘[e]ach year in the U.S., 10,000-15,000 abortions occur among women whose pregnancies are a result of reported rape or incest.’” “Todd Akin Challenged by Doctors on Rape and Pregnancy,” ABC News, August 21, 2012, URL = < >, retrieved May 3, 2013. What percentage of the total number of abortions is this? The latest government statistics on abortion are from 2009. According to the CDC (Centers for Disease Control), during that year 784,507 legal abortions were performed in the United States. Presumably, this figure is lower than the actual number, since states aren’t required to report these numbers to the CDC, and the figure cited does not include numbers from four states (California, Delaware, Maryland, and New Hampshire). (“Abortion Surveillance: United States, 2009,” Centers for Disease Control, URL = < >, retrieved May 3, 2013.)  Combining the two figures yields the result that legal abortions due to rape account for no more than 1-1.5% of legal abortions in the US each year. According to the Alan Guttmacher Institute, in 2008 (the most recent year for which the Institute provides statistics), 1.21 million legal abortions were performed in the United States. Combining that statistic with the estimate that 10-15,000 US abortions are due to rape or incest each year yields the estimate that no more than 1% of legal abortions are of pregnancies due to rape or incest. Of course, it is possible that this figure is too low because not all women who abort pregnancies that are in fact due to rape or incest report that this is the case.


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