I first heard about “the trolley problem” as an undergraduate philosophy student in 1991, as one of the countless thought-experiments moral philosophy uses to probe our intuitions regarding right and wrong, and whether we are consistent in our judgements of what is right/wrong. The problem, for those of you who don’t know it, is presented by its creator (Philippa Foot) as follows:
Suppose that a judge or magistrate is faced with rioters demanding that a culprit be found guilty for a certain crime and threatening otherwise to take their own bloody revenge on a particular section of the community. The real culprit being unknown, the judge sees himself as able to prevent the bloodshed only by framing some innocent person and having him executed.
Beside this example is placed another in which a pilot whose aeroplane is about to crash is deciding whether to steer from a more to a less inhabited area. To make the parallel as close as possible it may rather be supposed that he is the driver of a runaway tram which he can only steer from one narrow track on to another; five men are working on one track and one man on the other; anyone on the track he enters is bound to be killed. In the case of the riots the mob have five hostages, so that in both examples the exchange is supposed to be one man’s life for the lives of five.
A simple utilitarian response would be that the death of one is better than the death of five, and that we should intervene in both cases. Judith-Jarvis Thompson later expanded on the problem with thought experiments involving killing one person to harvest organs that could save 5 persons, and also with a variant involving pushing a fat man off a footbridge to derail a train, rather than the original scenario of steering a train from one track (where 5 would die) to another track (where one would die). Thompson’s paper is available online, for those who would like to read it.
As you can imagine, the purpose of raising the stakes – by making our interventions more direct – in these variants is to explore whether our reasoning stands up to scrutiny in being consistently principled, rather than being swayed by (potentially) irrelevant details regarding the nature of the protagonists and/or victims.
I bring the trolley problem up due to the recent publication (in The Atlantic) of a piece arguing that the trolley problem might be worthless as an experiment in psychology, rather than philosophy. The Atlantic piece describes arguments that the “fat man” variant is incomparable, because it typically provokes laughter, and “humor may alter the decision-making processes people normally use to evaluate moral situations”.
The same authors quoted immediately above criticise the trolley problem in general for being unrealistic (when was the last time you rode in a trolley, they ask). The lack of realism problem is to my mind silly – by that standard, we would be unable to do much moral philosophy except among subgroups who have experienced a particular situation. Men could not discuss abortion, the wealthy could not discuss poverty, and so forth.
The point, as I said at the top, is to use one example to think through whether we are consistently applying a set of principles to various iterations of a problem, or otherwise to become aware of how those iterations have crucial differences that make a different set of principles appropriate to them.
In other words, I agree with Joshua Greene, who is quoted in the conclusion of the Atlantic piece saying that the point is not “Let’s study trolley problems because they’re representative of problems we face in everyday life”, but rather “Here’s an interesting puzzle. If we follow it, we might learn something important”. Something important about how we reason, which factors influence reasoning, and so forth.
If you’d like to establish whether your views on these sorts of cases are consistent (at least, consistent according to one philosopher’s – Jeremy Stangroom – analysis), go and complete his quick philosophy experiment here: Should you kill the fat man?
And in closing, for philosophy geeks who haven’t heard of it, here’s a fun piece that riffs off the trolley problem as well as the “brain in a vat” thought experiment, titled “Can bad men make good brains do bad things?” (involving a brain in the vat at the wheel of a runaway trolley).