top of page

Thompson's Defence of Abortion: Relevant Today?

By Jack Walker - Philosophy Student @ Churchill College, Cambridge


A lot of writing about abortion concerns whether ending a pregnancy involves removing a ‘clump of cells’ or ending the life of a person. Since there appears to be no distinctive moment where an embryo suddenly becomes a person, neither side is clearly correct and little progress tends to be made. Judith Jarvis Thompson’s paper ‘A Defence of Abortion’ shifted the landscape by refusing to go down this rabbit hole. Instead, Thompson sought to argue that abortion is permissible no matter your views on personhood.

Here is a traditional anti-abortion argument:

  1. Foetuses are people.

  2. Each person has a right to life.

  3. Foetuses have a right to life.

  4. A right to life always trumps a right to personal autonomy.

Conclusion: Abortion is always wrong.

We will take P1 as true for the sake of argument and most people would agree to the truth of P2. Therefore, the success of our anti-abortion argument rests on P4. This seems convincing on a first read, but Thompson gives us a thought experiment which should cause us to doubt.

Imagine you are kidnapped and have your circulatory system connected to a violinist with failing kidneys. Your kidneys can be used to sustain her as well as yourself, whereas unplugging would kill her. Accepting P4 means that the violinist’s right to life would override your right to decide what is done to your body. As a result, you would be obliged to stay plugged into her until she could support herself, no matter how long this took. The parallel to pregnancy, especially in cases of rape, ought to be obvious.

Thompson argues that while it would be nice of you to save the violinist, our intuitions strongly suggest this cannot be morally required of us. Since accepting P4 leads us to this absurd result, there seemingly must be cases where abortion is acceptable, even if you buy P1.

In her paper, Thompson goes on to debunk more anti-abortion arguments through other thought experiments and it is well worth a read if you have time. Unfortunately, many powerful lawmakers, typically men, have little interest in a nuanced argument like Thompson’s, or even in basic biological facts. Perhaps the most egregious example comes from Missouri Congressman Todd Akin, who believes that women cannot become pregnant through rape because ‘the female body has ways to shut the whole thing down’. Examples like this show that many of those with power in the abortion ‘debate’ are not acting in good faith but instead seek only to exercise power over women’s bodies.

It is tempting to scoff at the situation in the USA. However, Northern Ireland only began to allow terminations under some circumstances in 2020, with even these provisions being described as a ‘postcode lottery’ by Amnesty International. These trends show why philosophy and politics must come together. Thompson’s argument is hugely creative and is certainly the most influential piece ever published on the topic. However, it is worthless if it is not coupled with effective political action in the real world.

Further reading:

  1. Thomson, Judith Jarvis, 'A Defence of Abortion', Philosophy & Public Affairs, 1, no.1 (1971): 47-66.

  2. Valenti, Jessica, ‘Anti-Abortion Lawmakers Have No Idea How Women’s Bodies Work’ in Medium (May 2019)

  3. Philosophy Tube, ‘Abortion and Ben Shapiro’,


bottom of page