In Defense Of Thought Experiments

Reviewing David Edmonds’ Would You Kill the Fat Man? The Trolley Problem and What Your Answer Tells Us About Right and Wrong, Robert Herritt suggests that the body politic could use intellectual exercise:

There’s a healthy tendency to dismiss these kinds of line-drawing disputes as frivolous or, even worse, lawyerly. Trolley examples in particular, as Edmonds admits, have grown so complex as to “stretch the limits of our credulity and imagination – the limits beyond which intuitions become fuzzy and faint.”

And yet, we confront fine-grained moral distinctions all the time, like when the NSA tells us there’s an important difference between monitoring the metadata of our phone calls and monitoring their actual content; or when lawmakers seek to ban some mind-altering substances but not others. How are we to make sense of the judgment that, if you’re a Syrian dictator, killing your own people with conventional weapons is one thing, but using sarin gas is quite another? And then there’s the issue that Philippa Foot was trying to clarify when she created the trolley problem all those years ago: abortion.

Many of us have strong beliefs about these matters and, one would hope, reasons for those beliefs. Even if you see trolleyology as a waste of time, it at least lays bare how truly difficult it is to figure out what those reasons are, much less to determine whether they are any good.

A review of the “trolley problem” thought experiment:

Philippa Foot‘s original formulation of the problem ran as follows:

Suppose that a judge or magistrate is faced with rioters demanding that a culprit be found 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 the exchange is supposed to be one man’s life for the lives of five.

A utilitarian view asserts that it is obligatory to steer to the track with one man on it. According to simple utilitarianism, such a decision would be not only permissible, but, morally speaking, the better option (the other option being no action at all). An alternate viewpoint is that since moral wrongs are already in place in the situation, moving to another track constitutes a participation in the moral wrong, making one partially responsible for the death when otherwise no one would be responsible. An opponent of action may also point to the incommensurability of human lives. Under some interpretations of moral obligation, simply being present in this situation and being able to influence its outcome constitutes an obligation to participate. If this were the case, then deciding to do nothing would be considered an immoral act if one values five lives more than one.

The initial trolley problem becomes more interesting when it is compared to other moral dilemmas. One such is that offered by Judith Jarvis Thomson is called “the fat man”:

As before, a trolley is hurtling down a track towards five people. You are on a bridge under which it will pass, and you can stop it by dropping a heavy weight in front of it. As it happens, there is a very fat man next to you – your only way to stop the trolley is to push him over the bridge and onto the track, killing him to save five. Should you proceed?