One of the most popular dilemmas in moral philosophy is the Trolley problem. The subject is vast, so here are the most interesting variations of it.
1. The original problem.
You observe an out-of-control trolley hurtling towards five people who will surely die if hit by the trolley. You can throw a switch and divert the trolley down a side track saving the five but with certainty killing an innocent bystander. There is no opportunity to warn or otherwise avoid the disaster. Do you throw the switch?
The initial trolley problem becomes more interesting when it is compared to other moral dilemmas. One such is that offered by Judith Jarvis Thomson.
2. The fat man.
As before, a trolley is hurtling down a track towards five people. You are on a bridge under which it will pass, and you can stop it by dropping a heavy weight in front of it. As it happens, there is a very fat man next to you – your only way to stop the trolley is to push him over the bridge and onto the track, killing him to save five. Should you proceed?
Resistance to this course of action seems strong; most people who approved of sacrificing one to save five in the first case do not approve in the second sort of case.
3. The tracks that rejoin
As before, a trolley is hurtling down a track towards five people. As in the first case, you can divert it onto a separate track. On this track is a single (fat) person. However, beyond that person, this track rejoins the main line towards the five, and if it weren’t for the presence of that (fat) person, who will stop the trolley, flipping the switch would not save the five. Should you flip the switch?
The only difference between this case and the original trolley problem is that an extra piece of track has been added, which seems a trivial difference (especially since the trolley won’t travel down it anyway). So, if we originally decided that it is permissible or necessary to flip the switch, intuition may suggest that the answer should not have changed. However, in this case, the death of the one actually is part of the plan to save the five.
A psychological approach to the problem. Utilitarianism may not only be a matter of rational opinion but one of character.
Daniel Bartels of Columbia University found that individual reactions to trolley problems is context sensitive and that around 90% would refuse the act of deliberately killing one individual to save five lives.
Further study by Daniel Bartels and David Pizarro focused on those 10% who made utilitarian choice. The study asked participants to series of value statement. The experiment found that those who had stronger utilitarian leaning had stronger tendency to psychopathy, Machiavellianism or tended to view life as meaningless.
The Economist magazine who reported this finding stated that “utilitarians, … may add to the sum of human happiness, but they are not very happy people themselves.”
For a more philosophers-oriented approach to the subject: