Pushing The Guy Off The Bridge And Flipping The Switch Aren't Morally Different By More Than An Arbitrarily Small Finite Amount Of Utility
Assuming modest assumptions
People often hold two judgments which appear to be in tension with each other. In the case of the trolley problem, where there is a train going towards 5 people unless you flip the switch to kill one person, people think you should flip the switch. However, in a different case, where the only way to stop a train from killing 5 people is to push one person off a bridge, people tend to think1 you shouldn’t push the guy. As I shall argue here, the moral equivalent is not merely superficial—those two actions are not morally different from each other. One’s judgment should thus be consistent across the cases.
This follows from an even more modest pareto principle, which says that if some action makes all affected parties better off, it is a good action. This is a rather plausible principle.
Next, consider the following case. One person is on a track over a bridge. A train is coming. There is a different track that leads up to the person over the bridge. There are two ways of stopping the train.
Flip the switch to redirect the train to to one person above.
Push the person onto the track. Doing so would have the additional effect of very very slightly increasing the utility of both the person pushed and of all of the other people on the tracks, relative to redirecting the train2.
It seems obvious that the better option is option 2. Option 2 is better than option 1 for all of the affected parties. However, option 2 is only an infinitesimal amount better than the ordinary case in which one pushes the person off the bridge. Thus, 2 which is an infinitesimal amount better pushing the guy is better than flipping the switch.
Ridiculously!!
Shoving them has a bizarre property in this case!