class in college or anything in the dilemma. i thought experiment used in more of philosophy. it's tough how our -- intuition. here's the simplest if you haven't heard of it before. let's just imagine you are watching a train, rolling down the tracks, and there are five unsuspecting workers on those tracks, it's about to run them over. it is right before a switch, you have an option to flip a lover to divert the train down a separate track, if you choose to pull that lever five people die. there are all kinds of ways to complicate this narrow, what if there is one work on the other track like you saw an illustration, five on one track, one on the other. what if there is family members of yours on one shaq, and, on.