What makes an action right · Quiz question 7/35
The Footbridge (Fat Man) Case
Push the man off the bridge and 5 live. How is that different from the lever? Thomson's footbridge case, Joshua Greene's fMRI study, and where philosophers land.
Same trolley, same 5 people. This time there's no lever. If you push a large man off the footbridge onto the track, the trolley stops and the 5 live. He dies.
You shouldn't push him.
Judith Jarvis Thomson introduced it in 1976 and developed it in "The Trolley Problem" (1985). The outcome is the same as the lever case — 1 dies, 5 live. Yet most people pull the lever but won't push the man.
So what's the difference? The most common answer: on the footbridge you use a person as a means. The 5 only live because his body stops the trolley. Kant's formula — never treat humanity merely as a means — is aimed right at this.
Psychologist-philosopher Joshua Greene's 2001 fMRI study found that "up close and personal" dilemmas like the footbridge light up emotion-related brain areas more. Greene argued deontological intuitions might be evolved emotional reactions, sparking a big debate about how far to trust moral intuitions. Many philosophers reply that emotion being involved doesn't make a judgment wrong.
Using a person as a tool is forbidden, no matter the outcome.
Key names: Kant, Robert Nozick, Frances KammSame outcome, same answer. Feeling a difference is just emotional bias.
Key names: Joshua Greene, Peter SingerA good person doesn't shove strangers off bridges. Character and judgment come before rules or math.
Key names: The Aristotle tradition, Bernard WilliamsIn the 2020 PhilPapers Survey, only about 22% of philosophers said push — a sharp contrast with the lever case (about 63%).