Judith Jarvis Thomson
1929 CE – 2020 CE · Contemporary Era
“Even if a fetus has a right to life, it does not follow that a woman is morally required to sustain it with her body.”
Biography
An American moral philosopher who spent her career at MIT. Educated at Barnard College, Cambridge University, and Columbia University. Her 1971 essay 'A Defense of Abortion', published in the inaugural issue of Philosophy & Public Affairs, is a widely anthologized paper in philosophy. She named and developed the trolley problem into the form now known worldwide, generating a vast 'trolleyology' literature spanning philosophy, psychology, and neuroscience.
Major Works
Key Arguments
Click “Philosophy 101” to read the full exploration of each argument.
The Violinist (A Defense of Abortion)
You wake up connected to a famous violinist who needs your kidneys to survive for nine months. The Society of Music Lovers kidnapped you and hooked you up. The violinist has a right to life, but does that right entitle him to the use of your body against your will? Thomson argued that it does not, and that the same logic applies to pregnancy. Even granting that a fetus has a full right to life from conception, it does not follow that anyone is morally obligated to provide their body as life support. The right to life does not include the right to use another person's body without consent.
Why it matters: Transformed the abortion debate by shifting it from the question of fetal personhood to the question of bodily autonomy. Demonstrated that philosophical thought experiments could illuminate the most contested moral issues of public life. Remains a widely assigned reading in applied ethics.
The Trolley Problem (Developed Form)
A trolley is headed toward five people. You can divert it onto a side track where it will kill one person instead. Most people say: divert. But now imagine you are on a bridge and can stop the trolley only by pushing a large man off the bridge into its path. Most people say: do not push. Thomson developed this contrast (building on Philippa Foot's original scenario) into a precise philosophical puzzle: both cases involve choosing between one death and five, yet our moral intuitions diverge sharply. Why? The answer requires understanding the difference between redirecting an existing threat and using a person as a means to save others.
Why it matters: Generated one of the largest literatures in contemporary ethics, with implications for moral psychology, neuroscience, autonomous vehicles, and AI ethics. Thomson's cases suggested that our moral intuitions have a complex structure that resists reduction to any single principle.
Rights and the Limits of Consequentialism
Thomson argued that rights are not simply rules of thumb that can be overridden whenever violating them would produce better consequences. Rights have genuine moral weight that constrains what we may do to people even for good ends. You may not harvest one person's organs to save five, even though the consequences would be better. The moral impermissibility of such acts reveals that there are constraints on how we may treat individuals that no amount of aggregate benefit can override.
Why it matters: Provided a rigorous analytical defense of moral rights against consequentialist challenge. Thomson's work on rights shaped the field of normative ethics and remains essential to debates about justice, individual liberty, and the limits of utilitarian reasoning.
Lasting Influence
Reshaped applied ethics with the violinist argument. Developed the trolley problem into the form that launched a thousand studies. The violinist argument for abortion rights is the most cited philosophical argument on that question; the strongest objection -- that obligations can arise from voluntary actions whose full consequences were foreseeable -- is one the argument does not fully answer.
Your Reading Path
The Companion Guide
Seven eras of philosophy in one volume — reading lists, key terms, journal prompts · $19.99