Desirism Wiki

The Trolley Car Problem is a case in moral philosophy and moral psychology in which a person is asked to make a moral choice involving a run-away trolley. The case is considered interesting because small changes in the description of the problem tends to produce major shifts in what people claim should be done - though the reason for the shift is hard to identify.

The Trolley Car Problem[]

The basic form of the trolley car problem goes as follows:

You are standing on the edge of a track, near a switch. A runaway trolley is coming down the track. Looking down the track, you see five workers who will certainly be killed if you do not act. You can pull the switch. This will send the trolley down a different track. There is only one worker on that track - though he would be killed if you pull the switch. Do you pull the switch?

Many are reluctant to pull the switch - to cause the death of somebody who would have otherwise lived.

If six people were trapped in a burning building, and you could either rescue five in one room or one person in the attic, few have difficulty deciding to rescue the five. Switching the track so that five people live rather than one seems to be a different type of case. It seems morally important to many people that the one worker on the track would have lived if they had not switched the track.

Some are willing to pull the switch and many at least take it to be an option worth considering. These people are provided a different version of the trolley car problem. In this version, one can stop the train by pushing a particularly fat man onto the tracks so that the train runs over him and stops. People who are willing to at least consider diverting the train to run over the worker are unwilling to push the fat man onto the tracks.

Desirism's Response to the Trolley Car Problem[]

Response to the Standard Version[]

What does desirism say about this example?

Desirism identifies a right act as the act that a person with good desires would perform, where good desires are malleable desires that people generally have many and strong reasons to promote using social tools such as praise and condemnation. Since desires are the only reasons that exist, the reasons to promote or inhibit certain desires are determined by the desire's tendency to fulfill other desires.

In evaluating a desire, people generally have a lot more reason to be concerned with the behavior that a desire will generate in regular day-to-day activities than with the behavior that the desire will generate in an imaginary and highly improbably situation such as that described in the Trolley Problem.

Given the assumptions of the trolley car problem, we can comfortably say that no person will ever find themselves in this situation.

The greatest problem making the Trolley Car situation impossible in real life rests with what the agent is assumed to know with no possibility of error. These are things that no agent can ever know in the real world. He knows that there is no other way to stop or divert the trolley. He knows that the five workers will be killed if she does not switch the train, and that one will be killed if she does not. These are certain.

Another set of improbabilities lies in the situation itself. How many times in human history has anybody actually found themselves at an unlocked switch she knows how to use with a run-away trolley that will kill a number of people unless diverted to a side track where it would kill fewer?

Because these situations never exist in the real world, it makes no sense for us to evaluate desires according to the actions they may motivate an agent to perform in that situation. People generally have no reason to evaluate desires according to the behavior that it might produce in this type of situation, or to use situations like this to judge a desire worth promoting or inhibiting with social tools.

In a real-world situation that could actually occur that comes closest to the Trolley Car case, desirism would argue that an agent should do nothing - but should be ready to take instructions. The reason is because the agent will not know what they are doing and their actions will often interfere with the plans of others tasked with working on the problem. Professionals in these types of cases are generally more successful if they do not have to deal with the uncertaint consequences of what others might do - even with good intentions.

In the real world, the person pulling the switch may have to deal with the discovery that employees of The Trolley Company had rigged a brake between the run-away trolley and the five workers that would have saved everybody's life. While this possibility is explicitly excluded in the story, the emotions that people generally have reason to promote are emotions suitable for real-world cases in which this is likely. Morality engineers desires to fit situations people will find themselves facing in the real world.

Note that these responses give a different answer in the case of rescuing the five people from the fire, rather than the one person in the attic. In the trolley case, the agent risks interfering with the work of professionals working on the problem. In the case of the fire, rescuing five people will likely free up resources that could be used to save the one person in the attic.

Response to the Fat Man Variation[]

Applying the principles of desirism, the problem with pushing the fat man in front of the tracks comes from asking ourselves, "How safe would we feel being surrounded by people with no aversion to killing any time they think they see an overall advantage?"

We recoil at the thought of pushing the fat man, and we want others to recoil as well.


Because people who recoil at the thought of pushing the fat man are safer neighbors. People who are willing and eager to push the fat man might decide to kill us for some perceived social benefit.

Desirism takes note on the fact that, while the Trolley Problem pretends to provide an agent with certain knowledge that pushing the fat man will kill one person and save five, this type of certainly is simply not available in the real-world situations that are used to evaluate the real-world consequences of particular desires and aversions.

Not only will real-world people almost never be certain of the outcome, many times when they are certain they will be wrong. The political positions that people take provide sufficient evidence that people do a poor job of perceiving social benefit - and that their vision is often clouded by personal advantage. A person comfortable with pushing the fat man on the tracks in the Trolley Car case would also be willing to kill people when personal advantage convinces them of an overall social benefit that simply does not exist. That makes them dangerous, and that makes it worthwhile to promote an aversion to acts such as pushing the fat man.

The fact that this aversion might prevent people from pushing a fat man in front of a runaway trolley in a highly idealized situation that can never happen in the real world is irrelevant. An aversion that fails to save five fictional lives can still save millions of real lives.

Real Responses to Imaginary Moral Problems[]

Desirism holds that we can never isolate an imaginary moral problem from the sentiments that people generally have real-world reasons to promote. People cannot have two sets of sentiments - one that they apply to imaginary cases and another that they apply to the real world. The sentiments that people use in deciding how to act in an imaginary case must necessarily be the same sentiments they use when acting in the real world.

This has important implications for how to understand the responses generated by hypothetical cases. We can never get out of asking the question, "What are the implications of a person having those sentiments that they are using in this imaginary case on real-world interactions?" Those implications are real.

Correspondingly, praise and condemnation are built into the meanings of moral terms. "Pushing the fat person is wrong" not only prescribes against the act pushing the imaginary fat person in front of the imaginary train. It also promotes a real-world aversion to such an act in real-world people. It is a statement that praises the person with an aversion to pushing the fat man and condemns the person who is willing to do so - and does this for the purpose of promoting that aversion.

Judging whether that aversion is worth promoting or inhibiting requires judging its impact in likely-to-occur real-world events.

At the same time, saying that it is permissible to push the fat man in front of the trolley tells people in the real-world not to have a real-world aversion to killing others if they perceive a social advantage. The sentiments with which we evaluate this type of case are sentiments with real-world consequences, and it is those real-world consequences rather than the consequences of the imaginary story that determine which sentiments people generally have reason to promote or inhibit. It is also the real-world consequences that determine which moral terms to apply to the imaginary case.