Every student of Ethics 101 wrestles with the trolley problem. In this moral exercise of the imagination, you are standing by train tracks watching a runaway trolley race towards 5 people who are going to be crushed unless you intercede. If you pull a lever, the trolley will divert onto a different track, where it is bound to kill one person. In this situation, is it better to be passive or active? Should you pull the lever or not?