I came across this today. It's a question of ethics, a moral dilemma. The basic problem goes as follows: There is a runaway trolley barreling down the railway tracks. Ahead, on the tracks, there are five people tied up and unable to move. The trolley is headed straight for them. You are standing some distance off in the train yard, next to a lever. If you pull this lever, the trolley will switch to a different set of tracks. However, you notice that there is one person on the side track. You have two options: (1) Do nothing, and the trolley kills the five people on the main track. (2) Pull the lever, diverting the trolley onto the side track where it will kill one person. Which is the correct choice? The idea is that people will make different decisions in different situations based on their morals and values. In the basic problem most people would choose to kill one to save the five (I would have too). However that changes if certain details are added, such as the one person is your spouse/ mother/ father, the five people are screaming, the five are criminals, etc.. Found it quite interesting.