We like to pretend our instructors teach as well as chess computers, but too often they don’t come close to that ideal. They are something far less noble, something that we are afraid to call by its real name, something quite ordinary: They are a mix of exemplars and nags and missionaries, packaged with a marketing model that stresses their nobility and a financial model that pays them pretty well and surrounds them with administrators. It’s no wonder that this very human enterprise doesn’t always work so well.