Normative Ethics and the Trolley Problem

In David Edmonds’ book, Would You Kill The Fat Man, variations on a thought experiment are used to expose problems in making ethical determinations. The thought experiment, attributed to the philosopher Philippa Foot, became known later through the work of Judith Jarvis Thomson as The Trolley Problem. The scenario of the simplest iteration of the Trolley Problem thought experiment, known henceforth as “Spur,” is as follows: a man is standing along some railway tracks as a trolley careens towards him out of control. If he does nothing, the trolley will hit five people tied to the track ahead, killing them. If, however, the man throws a switch, the trolley will be diverted onto a rail spur with only one person tied to it. Should the man throw the switch? This quandary already is complex, containing issues of causation and intention, reason and emotion. This basic thought experiment is then altered in what is called the “Fat Man” scenario. A fat man is leaning against the railing on a bridge over some trolley tracks, as another man stands by. This man notices that a trolley is about to pass under the bridge and hit five people tied to the track on the other side, killing them. Is it morally permissible to push the fat man onto the tracks below to stop the train and save the five people? The result in each instance for taking action would be the same—one person will be killed instead of five—but somehow the Fat Man scenario seems more like murder. Several other permutations of the scenario are defined to bring concerns about intention and cause into view, and through comparing our intuitions about these scenarios philosophers hope to learn something about morality. Ultimately, the author concludes that “ethical thinking cannot be systematized” in the way that the Trolley Problem attempts to do[1].  The moral realm is best understood not as a rigid set of rules but instead as a set of overlapping concerns that we assess in a dynamic process. To be virtuous people, deontological rules can help us understand what is at stake in making moral decisions, but we must determine what is best in each unique instance and then hold ourselves accountable to those who may disagree. I will show how utilitarianism and deontological views fall short in dealing with trolley scenarios, that an action can be deserving of both praise and censure, and that context and details can change the moral duties of a particular situation.

The book opens with a description of a real-life problem faced by Winston Churchill in the beginning of World War II. Churchill had an opportunity to provide faulty information to the Nazis that would cause their rockets to land in less-populated areas instead of in the middle of London. This is analogous to the Spur scenario, in that an existing danger which threatens many people can be influenced in such a way as to threaten fewer people. Many people intuitively believe that diverting the trolley in Spur is morally permissible, and some would even say it is morally obligatory. In another way of looking at it, by diverting the trolley you are causing the death of the one person. To say that “killing is wrong” is about as close as we come to an objectively true ethical statement. We value our existence and are aware of our mortality, and therefore we recognize the value of the lives of others. In the Judeo-Christian tradition, “thou shalt not kill” is the sixth of the Ten Commandments. Our intuition and experience, however, strongly indicate to us that there are some instances when killing is not as morally forbidden as others. If a woman is attacked by another person with intent to kill, our sensibilities tell us that she is morally required to defend herself and to protect her own life for her own benefit and the benefit of others. If the attacker should be killed while she is defending herself, that is incidental to the intention of her actions. Why is killing in one instance permissible or even obliged, but in another instance forbidden? This distinction is further explained through Aquinas’ Doctrine of Double Effect.

Aquinas was concerned with what has been called Just War theory, that is, under what circumstances is it morally permissible to wage war. An intentional killing, Aquinas thought, is always wrong. According to Edmonds, actions can be assessed by the DDE through four criteria: 1) the act considered independently of its harmful effects is not in and of itself wrong, 2) the intention is to create a good result and does not intend to cause harm; 3) the good cannot be achieved without the harm, and 4) the harm is not disproportionately greater than the good.[2] This doctrine points out that we consider the intention behind an action to be relevant to its moral composition. The death of the one person in Spur is foreseeable as a consequence of our action, but it is not intended. Throwing a switch is not in and of itself an immoral act, and was required to produce the greater good. This seems to be a good rule to follow, but it has some problems. For one, it seems faulty to claim that because an act is not in itself immoral, it is alright to do it knowing it will have a “separate” immoral effect. This could open the door to all manner of extrajudicial killings performed at a distance. Also, the family of the person killed is likely not going to share your view that this was a better outcome. Their intuition tells them that you have murdered their innocent loved one, and you should be held accountable. In an earlier iteration of the Spur scenario by Frank Chapman Sharp in 1908, it is the child of the man standing by the switch who must be sacrificed to save the five others[3]. Would it be morally obligatory for the man to kill his own son to save five strangers? Errol Lord doesn’t think it is even appropriate to deliberate about whether your loved one should be sacrificed[4]. In his essay, Justifying Partiality, Lord cites Bernard Williams as defending our partiality toward our loved ones as a valuable characteristic of our human experience[5]. This Spur scenario points out the shortcomings of abstract constructions since they can be dramatically changed by introducing more information. Our intuition is that a man could be forgiven for not being able to sacrifice his close relative, or himself, for the benefit of others.

Appealing to that intuition is the purpose of the Fat Man scenario, in which a person is deliberately killed to save five others. In the Spur scenario, it seems as if we are “merely redirecting an existing threat,” and it is the trolley that is doing the killing[6]. In Fat Man, we are directly causing the death of a person who was otherwise not at risk. To a Utilitarian, Edmonds suggests, Spur and Fat Man are exactly the same. The result is that five people are alive and one has died, which is a better outcome than five being dead and one alive. Utilitarianism proposes that promoting the “greatest happiness of the greatest number” should be the guide to moral action. While we are prepared to accept that as a guide for action in Spur, many of us are less likely to feel that way about Fat Man. It seems as if we are putting him in harm’s way, and it takes more of a direct action to produce the result. When people are closer to the action, they are less likely to act in a way that causes harm, even if they anticipate that it is for a greater good. The Fat Man scenario is likened to another called Transplant. Would it be permissible to kill a healthy person and use his organs to save the lives of five others? An argument can be made that it would cause the most happiness for the most people, but looking further dispels that notion. If we had a society in which our lives could be forfeit at a moment’s notice, we would all suffer a little dread all the time. This is itself a Utilitarian approach to explaining why Fat Man or Transplant would not be permissible. In the short run, more happiness is produced for more people, but in the long run, more people would suffer. Also, if people knew you were the kind of person who would push an innocent man to his death, you might find yourself socially ostracized at minimum, if not charged with murder outright. This shows that morality is not a zero-sum proposition. A person could be simultaneously praised and censured for acting a certain way. In an example in Edmonds’ book, a captain in a life boat decides to kill and eat his cabin boy to contribute to the survival of himself and the others. It was necessary to put the captain on trial for the action of killing the man regardless of whether he would have died anyway, although the circumstances of the situation mitigated his sentence. If the same action can be considered both morally obligatory and morally permissible, then the promise of a set of rules to guide our actions is shown to be folly.

Another interesting twist on the Fat Man scenario is in how actions are interpreted by people from different cultures or social stations. In India, the society has built up caste affiliations which include an intellectual caste and a warrior caste. When asked, Indian people thought that pushing the Fat Man to his death would be immoral for an intellectual but permissible for the warrior. How is it that the same action shifts morality depending on the agent? It is because we have different social expectations of different people in society. If in the Spur scenario the potential victims were all soldiers, we would no longer think of the one as being more innocent than the others because they all would have considered themselves to be at risk of death in their profession. If a civilian failed to sacrifice her own life to save five coworkers, we could cite her duty to preserve her own life as a defense of her action (or inaction), but if a soldier failed to sacrifice her own life to save five fellow soldiers, she would be seen as cowardly and derelict in her duty. The station a person has in society has an impact on our expectation of their moral action. A person in a position of authority over others is held to a higher standard when it comes to how they treat the people for whom they are responsible. Jonathan Haight’s Moral Foundation Theory can give some guidance here[7]. Because we have a respect for people in authority, there is a commensurate expectation that those in authority will not abuse that trust. The man from the warrior caste who pushes the Fat Man would be free from censure because society has put trust in him to strategically assess situations and make the best judgment. The Fat Man’s family can better accept his death within this framework. Authority when viewed this way is actually just a different form of justice.

In fact, trolley scenarios have much in common with Haidt’s framing of morality. The scenarios are relying on our intuition to try to learn something about our perception of moral behavior. This is just like Haidt’s claim that we feel things first and reason about them second. We just know that something is wrong about pushing a man to his death even if we believe it will save the lives of a group of other people. From that feeling we determine the reasons that our emotions are appropriate, through such mental gymnastics as parsing intention and foreseeability. Frances Kamm creates a variation of the trolley scenario to assert that moving the trolley in order to hit someone is wrong, but because it will hit someone is acceptable[8]. This is a dubious linguistic distinction that is essentially begging for forgiveness for knowing that your action or inaction brought about someone’s death. The most important of Haidt’s moral foundations are care/harm and justice, and the others can be thought of as variations on those two. Sanctity can be understood as a built-in revulsion reflex that developed to protect us from harm, loyalty is owed to those in one’s group who help to provide care and justice, and authority is imbued in those who are responsible for providing care and justice. Intention is important because it demonstrates that we wanted to do good. We are not comfortable with people who willfully do harm to people. Pushing the fat man feels like willfully harming someone regardless of the intention. It impacts our sense of justice, also. All of the potential victims are presumed innocent, and so no matter what the outcome, it feels unjust that someone was chosen to die. Even in the case of a soldier who accepted the risk of death, the parents can expect to receive a letter explaining that the death was not the preferred outcome, and that the actual desired effect of peace and liberty at home was caused by his sacrifice. The parents’ suffering, and their moral interpretation, is altered by the context in which they understand the actions to have taken place.

Another way to explain our misgivings about killing the Fat Man is by using Kant’s Categorical Imperative. Kant’s ethics require us to act in such a way that we would want everyone else to act similarly, and to not use human beings as a means to an end but as an end in themselves. Clearly, using a person to derail a trolley is using them as a means to an end, and so it would not be permissible by Kant. To my sensibilities, I would also not want people in the general population running about assessing the risks and benefits of pushing people to their death to save others. Pulling a switch is one thing, but the mental calculations it would take to achieve the desired effect in the Fat Man scenario do not strike me as easily accomplished. It is only mentioned briefly whether the Fat Man would consider jumping to his own death to save the others tied to the track[9]. If in fact he did this, the intuition of most people is that he would be a hero for having sacrificed himself for others. Jeff McMahan pointed out to Edmonds in a footnote that, strictly speaking, the Fat Man will have used himself as a means to an end, thereby going against Kant’s prescriptions[10]. Kant would seem to permit the Spur scenario, but perhaps not if the one person to be sacrificed were a relative. If people were universally willing to sacrifice their children, that would bode ill for the strength of familial ties that are an important aspect of society. In a different scenario, Kant thinks that it should be impermissible to lie to a person who has come to your house seeking to kill a refugee hidden there[11]. This is an example where a reasonable person might consider it permissible to lie to someone to save a life, just as it could be permissible to divert the trolley in Spur. It is also similar to the self-defense case mentioned earlier in that someone who intends harm is thought of as having given up an expectation of normal treatment. Lying to avoid someone’s death appeals to our sense of justice in the same way as killing to avoid being killed. Kant’s Categorical Imperative has other problems related to social influence and perspective. I may think that it would be best if everyone left their front door unlocked because it would signal trust to my neighbors and the community, but the police will think the practice is an invitation to criminals. Deciding which is the best standard will require experience and input from the others in my community.

Philippa Foot believed that the best way to handle moral situations was not so much by applying a set of rules but by cultivating a virtuous character.  Along with Elizabeth Anscombe and Iris Murdoch, Foot is credited with helping to resurrect the tradition of virtue ethics[12]. The abstract examples of trolley scenarios fail in part because they are so abstract. As soon as we start populating them with details, the moral considerations shift. Because real life moral situations are complex and dynamic, it is better to think of approaching them with rational tools and emotional sensitivity. Both Haidt and Aristotle stress that human beings have a combination of rational and emotional influences. While Haidt believes our emotional responses are primary, Aristotle thought that our emotional reactions could be trained by our reason over time. Bernard Williams has an objection to the idea that a person could weigh the benefits of killing someone to achieve some separate beneficial end[13]. Like Kant, he suggests that a person possessing the virtue of honesty simply tells the truth and does not deliberate over whether to tell the truth in a particular instance. That strikes me as short sighted. It isn’t that honesty is a fickle thing that one can define to suit one’s own purposes, it is that honesty is not appropriate to every instance because of competing priorities. Someone of practical wisdom will balance the need to be truthful with the need to not offend or violate someone’s trust. It seems many moral theorists would like to have a definitive answer where one is not to be found. If a black-and-white answer is not forthcoming, the moral theorist becomes concerned that we have invited a type of evil moral relativism where people can just indulge their vices as they see fit. The reality is that things are very seldom all black or all white—they are many shades and hues. While broad deontological moral theories may appeal to our sense of order, they attempt to experience the noumenal in a way that is simply not possible.

The best example from the book is that of a meteorologist trying to decide how to report an approaching hurricane. The people want to be told whether the hurricane will hit them or not, and how fast the wind will blow, and how long it will take to arrive. The meteorologist can only make her best guess of those things. If she is too conservative in her estimates and reports that it will be mild, and it turns out to be severe, people will die. If she tells people to prepare for extreme weather and it turns out to be mild, people will be less responsive to her reporting the next time, and that will cost lives.  What must she do? She must interpret her data, count on her training and experience, model her forecast with the best metrics available to her, and then report her findings in earnest. She needs to report the degree of certainty so that people can understand the limitations of the information. This is type of dynamic balance-seeking is similar to the “Third Way” approach that is evident in Aristotelian virtue ethics and Buddhism.

Utilitarianism and deontologies are good rules of thumb, but can never be appropriate to every circumstance. These abstract trolley scenarios are helpful to tease out some details about what it means to act morally, especially since they are designed to elicit an emotional response. When we try to force moral considerations into a purely rational construct, we are making a basic error. Because of complex social environments and differing personal constitutions, making competent assessments of the moral content of actions necessarily requires consideration of all the details. The morality of a particular action can be altered by variables such as social status, privacy, intention, or personal relationships. Because of these dynamic attributes, Third Way philosophies such as virtue ethics provide a more stable general means to approach moral problems.


Matthew Ebert
PHIL 450 – 1001
Dr. Katharine Schweitzer
3 May 2017




Edmonds, David. Would You Kill the Fat Man?: The Trolley Problem and What Your Answer Tells Us about Right and Wrong. Princeton University Press, 2014.

Haidt, Jonathan. 2012. The righteous mind: Why good people are divided by politics and religion. First ed. New York: Pantheon Books.

Lord, Errol. 2016. Justifying partiality. Ethical Theory and Moral Practice 19 (3): 569-90.

Sharp, Frank Chapman, 1866-1943. 1908. A study of the influence of custom on the moral judgment. Bulletin of the University of Wisconsin, No. 236, Madison, Wisconsin, USA: P138.

[1] Edmonds, David. Would You Kill the Fat Man?: The Trolley Problem and What Your Answer Tells Us about Right and Wrong. Princeton University Press, 2014.

[2] Edmonds, David. Would You Kill the Fat Man?: The Trolley Problem and What Your Answer Tells Us about Right and Wrong. Princeton University Press, 2014.

[3] Sharp, Frank Chapman, 1866-1943. 1908. A study of the influence of custom on the moral judgment. Bulletin of the University of Wisconsin, No. 236, Madison, Wisconsin, USA: P138.

[4] Lord, Errol. 2016. Justifying partiality. Ethical Theory and Moral Practice 19 (3): 569-90.

[5] Lord, 584.

[6] Edmonds.

[7] Haidt, Jonathan. 2012. The righteous mind: Why good people are divided by politics and religion. First ed. New York: Pantheon Books.

[8] Edmonds, 56.

[9] Edmonds, 38.

[10] Edmonds, 195.

[11] Edmonds, 170.

[12] Edmonds, 172.

[13] Edmonds, 172.