The Trolley Problem: From Thought Experiment to Moral Psychology
The Trolley Problem: From Thought Experiment to Moral Psychology
What the Problem Is
Runaway trolley: divert it, or let five die
Footbridge variant: push one to save five
Transplant variant: harvest one healthy patient
A philosophical tool, not a real policy question
Origins
Philippa Foot, 1967: abortion and double effect
Judith Jarvis Thomson, 1976: killing vs letting die
The doctrine of double effect: intention matters
From academic journals to internet memes
The Core Arguments
Utilitarian case: five lives outweigh one
Deontological case: never use people as mere means
Acting vs refraining: why the difference feels real
Trolley vs footbridge: why intuitions diverge
The Empirical Turn
Surveys: most divert, almost nobody pushes
Brain scans: personal dilemmas light up emotion centers
Cultural variation in responses
What responses reveal about our moral wiring
Common Misunderstandings
It is not really about trolleys
'Do nothing' is also a choice with consequences
There is no official correct answer
Real cases differ from the idealized setup
Extensions Today
Self-driving cars: who does the car protect
The Moral Machine experiment at MIT
AI alignment: whose values get encoded
Open question: can machines be moral agents