Judith Jarvis Thomson

Judith Jarvis Thomson was an American moral philosopher who taught for most of her career at MIT. Her essay "A Defense of Abortion" (1971) granted for argument's sake that the fetus is a person and argued that a right to life does not include a right to use another person's body, illustrated by the famous violinist case. She also named and refined the trolley problem, sharpening the contrast between killing and letting die, and developed a systematic theory of rights.

Key ideas

• Even if the fetus is a person, its right to life does not by itself entitle it to the use of another's body.
• In the violinist case, being kept plugged into a stranger to sustain his life is generous, not obligatory.
• Trolley cases, including her bystander variant, test whether it matters morally if one kills or lets die.
• Rights form a structured system of claims, privileges and powers that can be weighed and forfeited.

Major works

• "A Defense of Abortion" (1971, Philosophy & Public Affairs)
• "Killing, Letting Die, and the Trolley Problem" (1976, The Monist)
• "The Trolley Problem" (1985, Yale Law Journal)
• The Realm of Rights (1990)

In the conversation

• Question Why did Philippa Foot invent the trolley case, and what did Judith Jarvis Thomson change? Sam Ellery · 4 replies
• Debate Most abortion arguments are really disputes about what grounds moral status, and we should say so Miriam Adler · 5 replies