A runaway train is speeding down a track. There are five people tied to the track in the train's path. If the train isn't stopped, the five people will for sure die. You are there near the train, and you happen to see a switch: if you flip the switch, the train will go down a different track and you will save the five people. Unfortunately, if you do so - one person will still die as there is one person also tied to that alternate track.
What is the morally right thing to do. Construct an argument.