Philippa Foot is most known for her invention of the Trolley Problem thought experiment in the 1960s. A lesser known variation of hers is as follows:
Suppose that a judge is faced with rioters demanding that a culprit be found for a certain crime. The rioters are threatening to take bloody revenge on a particular section of the community. The real culprit being unknown, the judge sees himself as able to prevent the bloodshed from the riots only by framing some innocent person and having them executed.
These are the only two options: execute an innocent person for a crime they did not commit, or let people riot in the streets knowing that people will die. If you were the judge, what would you do?
These sort of thought experiments are helpful to drive home the point that in creating public policy, sometimes you do need a way to quantify the value of human life, which gets to the ugly truth that we do value lives differently everyday in society. ER triage will save the sickest person first, all else being equal. But when things get swamped children often get prioritized up. We value young life more. The trolley problem forces the concept of assigning value to life and taking action based on that.
This second problem doesn’t do so as cleanly. In my opinion, the right answer is to let them riot, but also alert the police and seek to mitigate the harm they cause. This problem feels less about the quantification of human life than about moral culpability of actions. The trolley is acting as it must die to physics. It isn’t good or evil and has no agency. On the second problem, the rioters have agency, are choosing to do evil, and should be fought against.
Just my quick take though.