Teaching through inquiry doesn't come automatically--professors have to think of instruction in a different way. Instead of describing information that students should know, they must challenge students to think at a higher, critical-thinking level than they are accustomed to. After all, the most important aspect of a professors' job or "business" is to teach students how to think. In this month's column, the author describes the importance of teaching this critical skill and imparts insight into the theory of learning.