One of the most famous thought experiments in ethics is known as the trolley problem. The trolley problem is as follows: an unmanned trolley is heading down a track. A mad philosopher has tied five people to the track who will be killed if the trolley continues on its course. However, there is an alternate track on which the trolley could run if a switch were flipped, and on this track is tied a single person. You have the power to flip the switch. What do you do?
The problem is designed to bring out the differences in competing moral theories. Some ethicists suggest it is worse to kill someone than to let him die. They say that flipping the switch makes you an active participant in the killing in a way that you are not if you just let the trolley run its course. Other ethicists do not see the sharp distinction between action and inaction, and argue that refusing to flip the switch is itself an action. The problem then becomes whether we think five lives are more valuable than one.
If you think flipping the switch is the obvious choice, consider this variation of the trolley problem: a doctor is treating five patients, all of whom will die without an organ transplant. A healthy man walks into the hospital for a routine check-up. The doctor looks at the man and sees two lungs, two kidneys and a heart.
There are countless variations of the problem; each one intended to elicit a different combination of intensely emotional and coolly rational responses. It may seem like a trivial observation, but the easiest way to prompt an emotional response to the trolley problem is to move your listener from the switch to the track. Instead of looking at the problem as an unaffected third party, imagine that it is your life on the line.
When you put yourself in the shoes of the person on the alternate track, it doesn’t seem so obvious that flipping the switch is the best decision. If you were the one tied up, and you saw someone flip the switch, how would you react? Would it matter how many people were on the other track? If you saw 100 people on the other track, would you say to yourself, “Well, it looks like I have to be the one to die.”? I suspect that most people would be horrified of being run over by a trolley, and would have a hard time calmly rationalizing someone else’s decision to kill them with it.
I think this insight has wider application than just hypothetical ethical problems. I think it can be applied to warfare. No matter how obviously just an invasion is to a third party, it’s almost never seen as just by those who are victims in the invaded country.