Lectures often emphasize rote learning rather than critical thinking. Topics are discussed sequentially, not critically. The teacher does the talking and most of the thinking. The student memorizes material and is placed in a passive role. But many teachers who use the lecture should also be concerned that their students learn to think critically. One way to increase the emphasis on critical thinking while using a lecture format is to ask questions. Questioning can stimulate interaction between teacher and learner and challenge the learner to defend his or her position. In other words, the student must think critically. This article discusses what critical thinking is and how to bring it into the classroom.