Ever since Socrates, teaching has been a difficult and even dangerous profession. Why is good teaching such hard work? In this provocative, witty, and sometimes rueful book, David K. Cohen writes about the predicaments that teachers face. Like therapists, social workers, and pastors, teachers embark on a mission of human improvement. They aim to deepen knowledge, broaden understanding, sharpen skills, and change behavior. One predicament is that no matter how great their expertise, teachers depend on the cooperation and intelligence of their students, yet there is much that students do not know.