Concept

Trolley problem

Overview

The trolley problem is a thought experiment in moral philosophy and moral psychology with many variations, involving hypothetical ethical dilemmas about whether to sacrifice one person to save a larger number of people. The series usually begins with a scenario in which a runaway trolley (tram) or train is on course to collide with and kill a number of people (traditionally five) tied to the tracks, but a driver or bystander can intervene and divert the vehicle to kill just one person on a different track. Then other variations of the runaway vehicle, and analogous life-and-death dilemmas (medical, judicial, etc.) are posed, each containing the option either to do nothing—in which case several people will be killed—or to intervene and sacrifice one initially "safe" person to save the others.

Opinions on the ethics of each scenario turn out to be sensitive to details of the story that may seem immaterial to the abstract dilemma. The question of formulating a general principle that can account for the differing judgments arising in different variants of the story was raised in 1967 as part of an analysis of debates on abortion and the doctrine of double effect by the English philosopher Philippa Foot. Later dubbed "the trolley problem" by Judith Jarvis Thomson in a 1976 article that catalyzed a large literature, the subject refers to the meta-problem of why different judgements are arrived at in particular instances.

Thomson and the philosophers Frances Kamm and Peter Unger have analyzed the trolley problem extensively. Thomson's 1976 article initiated the literature on the trolley problem as a subject in its own right. Characteristic of this literature are colourful and increasingly absurd alternative scenarios in which the sacrificed person is instead pushed onto the tracks as a way to stop the trolley, has his organs harvested to save transplant patients, or is killed in more indirect ways that complicate the chain of causation and responsibility.

Earlier forms of individual trolley scenarios antedated Foot's publication. Frank Chapman Sharp included a version in a moral questionnaire given to undergraduates at the University of Wisconsin in 1905. In this variation, the railway's switchman controlled the switch, and the lone individual to be sacrificed (or not) was the switchman's child. The German philosopher of law Karl Engisch discussed a similar dilemma in his habilitation thesis in 1930, as did the German legal scholar Hans Welzel in a work from 1951. In his commentary on the Talmud, published in 1953, Avrohom Yeshaya Karelitz considered the question of whether it is ethical to deflect a projectile from a larger crowd toward a smaller one. Similarly, in The Strike, a television play broadcast in the United States on 7 June 1954, a commander in the Korean War must choose between ordering an air strike on an encroaching enemy force, at the cost of his own 20-man patrol unit; and calling off the strike, risking the lives of the main army of 500 men.

Beginning in 2001, the trolley problem and its variants have been used in empirical research on moral psychology. It has been a topic of popular books. Trolley-style scenarios also arise in discussing the ethics of autonomous vehicle design, which may require programming to choose whom or what to strike when a collision appears to be unavoidable. More recently, the trolley problem has also become an Internet meme.

Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).

Possible passages

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A third reason why the doctrine of liberty has generally been better received in the world, than its antagonist, proceeds from religion, which has been very unnecessarily interested in this question. There is no method of reasoning more common, and yet none more blameable, than in philosophical debates to endeavour to refute any hypothesis by a pretext of its dangerous consequences to religion and morality. When any…
David Hume, A Treatise of Human Nature
Close in meaning to Trolley problem; the term itself is not named.
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Unstable equilibrium, rapid fermentation, and a succession of explosive reports are thus the chief notes of modern ethics. Scepticism and traditionalism, empiricism and rationalism, crude naturalisms and all-embracing idealisms, flourish side by side--all the more flourish, one suspects, because side by side. Spencer exults because natural science reveals that a rapid transit system of evolution is carrying us…
John Dewey, The Influence of Darwin on Philosophy, and other essays in contemporary thought
Close in meaning to Trolley problem; the term itself is not named.
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X. THE MORAL SITUATION 201 Distinguishing marks of the moral situation, 201; Traits of voluntary activity, 202; The good and bad in non-voluntary behavior, 203; Indifferent voluntary conduct, 205; The moral is introduced when ends have conflicting values, 207; Selection then depends upon, and influences, the nature of the self, 209. XI. PROBLEMS OF MORAL THEORY 212 Theory grows from practical problems, 212; Three…
John Dewey, Ethics
Close in meaning to Trolley problem; the term itself is not named.
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Philosophers who discussed Trolley problem

Related ideas

Opposing perspectives

Moral reasoning

Place in the tradition

Part of Analytic philosophy.

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