You are walking on a bridge above a railway track and notice, to your horror, that five people are tied to the rails in the path of the oncoming rail trolley. You see that in front of you is a man teetering on the edge of the bridge, a man so large and fat that his sheer bulk would stop the trolley in its tracks and save the five people currently in the path.
Do you push the fat man off the bridge ?
See also: Trolley question blogjune 2014 #4