This chapter explores the duties of college teachers to teach and mentor undergraduate students. It argues that teaching and mentoring are currently suboptimal because college teachers are not trained to do either, and have little incentive to improve. The result is that students emerge from college suboptimally prepared both to participate productively in the economy and to participate reasonably and responsibly as democratic citizens. This is a cost to them, and to the public good. Reform is needed. But the second half of the chapter argues that, even absent reform, and even absent improvement from their colleagues, individual college teachers have stringent responsibilities to improve their own teaching and mentoring.