Philosophers think out all kinds of theoretical situations in order to discuss and answer their philosophical questions. However, it often happens that such a thought experiment starts from assumptions that push the answer looked for already into a certain direction. Thought experiments in which people switch brains are like that: how can we theoretically discuss brain switches and come to acceptable conclusions if we ignore factors that make such brain swaps impossible in practice? (see my “Can a person break a world record?” on http://home.kpn.nl/wegweeda/PersonalIdentity.htm ). An article by Allen Wood (“Humanity as End in Itself” in Derek Parfit, On What Matters, Vol. Two, pp. 58-82) drew my attention to another factor that is often left out, although it is usually relevant for the problem at hand: the context. In what follows I am greatly indebted to this article.
Two much discussed thought experiments in philosophy (also by Wood and Parfit) are “Sidetrack” and “Footbridge”:
Sidetrack: A driverless, runaway trolley on a railway is heading for a tunnel, in which it would kill five people. As a bystander, you could save their lives by turning a switch and redirecting the trolley on to another track. However, there is a man walking on that track that would be killed instead of the five.
Footbridge: A driverless, runaway trolley on a railway is heading for a tunnel, in which it would kill five people. You are standing on a footbridge above the track. You are slim and short but a large man is just crossing the bridge. If you jump on the track, you will be run over by the trolley, which will kill you and the five people as well. If you push the large man on the track, he will be killed but the trolley will stop and the five will be saved.
Most people will say that it is permissible that you turn the switch in Sidetrack but not that you push the man in Footbridge. One explanation for this difference is that it is impermissible to intentionally cause harm as in Footbridge, but permissible to cause harm as a foreseen but unintended consequence of one’s action as in Sidetrack.
Whatever the explanation is, one can wonder how people would react if
- the five people are walkers who want to take a short cut but are not allowed to walk in the tunnel
- the five people are copper thieves stealing railway copper
- the single person is a railway worker doing his job.
- it’s not you who have to take the decision but a mentally weak person who often takes wrong decisions.
- the large man in Footbridge is an escaped murderer (sentenced to death, if that makes a difference to you).I can give my thoughts free rein and add more situations or I can combine them. However, I think that one thing is clear: what you’ll do and what you’ll find permissible will depend on the situation. It has no sense to strip off the context and then in the abstract tell what is right, or, in other thought experiments, what we’ll do. It’s the context that makes what is acceptable or right, and this context is often more complicated than we can imagine in our philosophical armchair.