The Philosopher’s Index (a database) turns up 25 articles that concern “trolley problems.” That’s actually fewer than I expected, given how frequently such problems seem to arise in conversation. Briefly, they involve situations in which an out-of-control trolley is barreling down the tracks toward potential victims, and you can affect its course by throwing a switch that sends it plowing into a smaller group of victims, or by throwing an innocent person in front of the tram. Or you can refrain from interfering.
The purpose of such thought experiments is to use our intuitions as data and learn either: (a) what fundamental principles actually underlie our moral choices, perhaps as a result of natural selection, or (b) which moral theory would consistently and appropriately handle numerous important cases. In either case, the “trolley” story is supposed to serve as an example that brings basic issues to the fore for consideration. The assumption is that we have, or ought to have, a relatively small set of general principles that generate our actual decisions.
I do not think this approach is useless, but it doesn’t interest me, for the following reason. When I consider morally troubling human interactions and choices, I imagine a community or an institution like a standard American public school. The issues that arise, divide, perplex, and worry us in such contexts usually look like this: Ms. X, a teacher, believes that Mr. Y, her colleague, is not dedicated or effective. How should she relate to him in staff meetings? Or, Ms. X thinks that Johnny is not a good student. Johnny is Latino, and Ms. X is worried about her own anti-Latino prejudices. Or, Ms. X assigns Charlotte’s Web, a brilliant work of literature but one whose tragic ending upsets Alison. Should Alison’s parents complain? Or, Mr. and Mrs. B believe that Ms. X is probably a better teacher than Mr. Y. Yet they cannot be sure. Should they try to get their little Johnny into Ms. X’s class, even if that means insulting Mr. Y? Or should they allow Johnny to be assigned by the principal?
Possibly, philosophy has little value in guiding, or even analyzing, such choices. I would like to think that is wrong, and philosophical analysis can be helpful. But it is very hard to see how trolley problems can get us closer to wise to judgment about concrete cases.