What would you do in the first instance? Would you do the same in the other two instances? Why or why not?
1. A trolley is running out of control down a track. In its path are 5 people who have been tied to the track by a mad philosopher. Fortunately, you can flip a switch which will lead the trolley down a different track. Unfortunately, there is a single person tied to that track. Should you flip the switch? (Philippa Foot)
2. 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? (J.J. Thomson)
3. As before, a trolley is hurtling down a track towards five people. You can divert its path by colliding another trolley into it, but if you do, both will be derailed and go down a hill, across a road, and into a man's yard. The owner, sleeping in his hammock, will be killed. Should you proceed? (Peter Unger)
From Wikipedia, "Trolley Problem"