Would You Kill the Fat Man? The Trolley Problem and What Your Answer Tells Us About Right and Wrong
Are certain actions intrinsically wrong, or are they wrong only because of their consequences? Suppose that by torturing someone, you could save a human life, or ten human lives, or a hundred. If so, would torture be morally permissible or perhaps even obligatory? Or imagine that capital punishment actually deters murder, so that with every execution, we can save two innocent lives, or three, or a dozen. If so, would capital punishment be morally permissible or perhaps even mandatory? And how, exactly, should we go about answering such questions?
On one view, the best method, and perhaps the only possible one, begins by examining our intuitions. Some people have a firm conviction that it is wrong for the government to torture or execute people, even if doing so would deter murder. Some people think that it is plain that a nation should not bomb a foreign city, and thus kill thousands of civilians, even if the bombing would ultimately save more lives than it would cost. If we are inclined to agree with these conclusions, we might test them by consulting a wide range of actual and hypothetical cases. That process could help us to refine our intuitions, eventually bringing them into accord with one another, and also with general principles that seem to explain them, and that they in turn help to justify.
Many philosophers are inclined to this view. To test our moral intuitions and to see what morality requires, they have been especially taken with a series of moral conundrums that sometimes go under the name of “trolleyology.” Here are two of the most important of these conundrums.
1. The Trolley Problem. You are standing by the side of a railway track, and you see a runaway train coming toward you. It turns out that the brakes have failed. Five people are tied to the track. They will be killed unless you do something. As it happens, you are standing next to a switch. If you pull it, the train will be diverted onto a side track. The problem is that there is a person tied to the side track, and if you pull the switch, that person will be killed. Should you pull the switch?
2. The Footbridge Problem. You are standing on a footbridge overlooking a railway track, and you see a runaway train coming toward you. It turns out that the brakes have failed. Five people are tied to the track. They will be killed unless you do something. A fat man is near you on the footbridge, leaning over the railway, watching the train. If you push him off the footbridge, he will fall down and smash onto the track. Because he is so obese, he will bring the train to a stop and thus save the five people—but he will be killed in the process. Should you push him?
Most people have pretty clear intuitions about the two problems. In the Trolley Problem, you should pull the switch, but in the Footbridge Problem, you should not push the fat man. The question is: What is the difference between the two cases? Once we identify the answer, perhaps we will be able to say a great deal about what is right and wrong—not only about trolleys and footbridges, but also about the foundations of ethics and the limits of utilitarian ways of thinking. What we say may bear in turn on a wide range of real-world questions, involving not only torture, capital punishment, and just wars, but also the legitimate uses of coercion, our duties to strangers, and the place of cost-benefit analysis in assessing issues of health and safety.
In an elegant, lucid, and frequently funny book, Would You Kill the Fat Man?, David Edmonds, a senior research associate at Oxford, explores the Trolley and Footbridge Problems, and what intelligent commentators have said about them. Philippa Foot, who taught philosophy at Oxford from the late 1940s until the mid-1970s, was the founding mother of trolleyology (and also the granddaughter of Grover Cleveland).
Though Oxford was dominated by men in this period, three of its leading philosophers were women: Foot, Elizabeth Anscombe (for whose appointment Foot was responsible), and Iris Murdoch. Edmonds explains that their mutual entanglements, philosophical and otherwise, were not without complications. Murdoch’s many discarded lovers included M.R.D. Foot, who became Philippa’s husband. The marriage badly strained the relationship between the two women (“Losing you & losing you in that way was one of the worst things that ever happened to me,” Murdoch wrote to Philippa). After M.R.D. Foot left his wife, she and Murdoch again became friends (and had a brief love affair themselves).
Anscombe once said that Foot was the only Oxford moral philosopher worth heeding, but the two had a terrible falling out over contraception and abortion, which Foot believed to be morally permissible. Anscombe vehemently disagreed, using the term “murderer” to describe “almost any woman who chose to have an abortion.” Foot thought that Anscombe was “more rigorously Catholic than the Pope.”
The Trolley Problem grew directly out of these debates. Haunted by World War II and its horrors, Foot rejected the view, widespread in Oxford circles at the time, that ethical judgments are merely statements of personal preference, and also the claim that the best way to analyze those judgments is to see how the relevant words are used in ordinary language. Foot believed that ethical judgments could be defended as a matter of principle. In 1967, she published an article, “The Problem of Abortion and the Doctrine of the Double Effect,” which introduced the Trolley Problem.
The Doctrine of Double Effect is well known in Catholic thinking. It distinguishes sharply between intended harms, which are impermissible, and merely foreseen harms, which may be permissible. According to Catholic theology, a woman is permitted to have a hysterectomy if necessary to remove a life-threatening tumor, even if a fetus in her womb will die as a result. The reason is that her intention is to save her own life, not to kill the fetus. To explore the distinction between intended and foreseen effects, Foot introduced a number of hypothetical dilemmas, including the Trolley Problem and the Transplant Case, which asks whether a surgeon should kill a young man in order to farm out his organs to save five people who are now at risk. Foot thinks it plain that the surgeon is not permitted to kill the young man, even if lives would be saved on balance. (Interestingly, Foot did not reach a conclusion on the question whether a woman may have an abortion when her life and health are not in danger.)
Perhaps the Doctrine of Double Effect can explain why it is right to pull the switch in the Trolley Problem (where you don’t intend to kill anyone) but wrong in the Transplant Case to kill the young man (whose death is intended). But in an intricate argument, Foot ultimately concluded that the best way to explain our conflicting intuitions in such cases is to distinguish not between intended and foreseen effects, but between negative duties (such as the duty not to kill people) and positive ones (such as the duty to save people). In a later article, Foot emphasized that in the Trolley Problem, the question is whether to redirect an existing threat, which might be morally acceptable, unlike the creation of a new threat (as in the Transplant Case).
The Footbridge Problem was devised and made famous by Judith Jarvis Thomson, a philosopher at the Massachusetts Institute of Technology. In asserting a moral distinction between the Trolley Problem and the Footbridge Problem, Thomson drew attention to people’s rights. In Thomson’s view, the fat man has a right not to be killed, but the same is not true of the person with the misfortune to be tied up on the side track in the Trolley Problem. “It is not morally required of us that we let a burden descend out of the blue onto five [persons] when we can make it instead descend onto one.” A bystander cannot push someone to his death, but he can legitimately seek to minimize “the number of deaths which get caused by something that already threatens people.”
Edmonds observes that in her work on these questions, Thomson was speaking as a follower of Immanuel Kant, who believed that people should not be treated merely as means to other people’s ends. Foot herself had referred to the “existence of a morality which refuses to sanction the automatic sacrifice of the one for the good of the many…[and] secures to each individual a kind of moral space, a space which others are not allowed to invade.” Many people believe that when we insist that it is morally unacceptable to push the fat man (or to steal people’s organs, or to torture or execute innocent people), we are responding to deeply felt Kantian intuitions, and rightly so.
Of course it is true that utilitarians reject those intuitions and insist that “the good of the many” is what matters. On utilitarian grounds, the Trolley Problem and the Footbridge Problem seem identical and easy to resolve. You should pull the switch and push the fat man, because it is better to save five people than to save one. But in a discussion that bears directly on the Footbridge Problem, and that might be enlisted on the fat man’s behalf, John Stuart Mill emphasized that from the utilitarian point of view, it might be best to adopt clear rules that would increase general “utility” in the sense of overall well-being or social welfare, even if they would lead to reductions of utility in some individual cases. In Edmonds’s words:
It would be disastrous if, each time we had to act, we had to reflect on the consequences of our action. For one thing, this would take far too much time; for another, it would generate public unease. Far better to have a set of rules to guide us.
In principle, utilitarian judges should be willing to convict an innocent person, and even to execute him, if the consequence would be to maximize overall well-being. But a utilitarian might acknowledge that if our legal system were prepared to disregard the question of guilt or innocence, it might collapse. In many situations, we live by simple rules that perform well as far as the aggregate is concerned and that make life a lot easier than case-by-case judgments would. Edmonds writes:
It would be unsettling to have to worry that any time you visited a sick relative in hospital, it might be you who ended up under the scalpel with surgeons cutting out your organs. So, we should adhere to the rough-and-ready rules.
Even if we accept this conclusion, utilitarians should be prepared to admit that it would be acceptable and indeed obligatory to push the fat man under imaginable circumstances—if, for example, social cohesion would not be at risk, and no one would ever learn what happened. In response, Edmonds invokes a famous argument by Bernard Williams, who contended that in problems of this kind, utilitarianism points in the wrong direction. Williams devised a now-famous case, closely akin to the Footbridge Problem, in which a character named Jim finds himself in a South American town in which armed men are getting ready to shoot twenty innocent people. The leader of the men tells Jim that if he shoots one of the twenty, the other nineteen will be freed. Should Jim shoot?