Prospect's David Edmonds reports on a thought experiment rising in popularity among moral philosophers: "trolleyology."
Moral philosophers have long debated under what circumstances it is acceptable to kill and why, for example, we object to killing a patient for their organs, but not to a distribution of resources that funds some drugs rather than others.
To understand the debate you need to understand the trolley problem. It was conceived decades ago by two grande dames of philosophy: Philippa Foot of Oxford University (click here to read more about Foot) and Judith Jarvis Thomson of MIT. The core problem involves two thought experiments—call the first “Spur” and the second “Fat Man.”
In Spur, (see diagram one, below), an out-of-control trolley—or train—is hurtling towards five people on the track, who face certain death. You are nearby and, by turning a switch, could send the trolley onto a spur and save their lives. But one man is chained to the spur and would be killed if the trolley is diverted. Should you flick the switch?
In Fat Man (see diagram two), the same trolley is about to kill five people. This time, you are on a footbridge overlooking the track, next to a fat man. (The Fat Man is now sometimes described as a large gentleman. But fat or large, the fact of his corpulence is essential.) If you were to push him off the bridge onto the track his bulk would stop the trolley and save the lives of those five people—but kill him. Do you push him?
From here the experiment bifurcates into variants with names like Loop and Lazy Susan, each of which in its own way addresses the Principle of Double Effect, which explainsthe permissibility of an action that causes a serious harm, such as the death of a human being, as a side effect of promoting some good end. It is claimed that sometimes it is permissible to cause such a harm as a side effect (or “double effect”) of bringing about a good result even though it would not be permissible to cause such a harm as a means to bringing about the same good end. This reasoning is summarized with the claim that sometimes it is permissible to bring about as a merely foreseen side effect a harmful event that it would be impermissible to bring about intentionally.
To see how you would respond in this soon-to-be-classic situation as the moral agent, take this quick quiz.