Tamar Gendler, professor of philosophy at Yale, opens this lecture from Philosophy and the Science of Human Nature (PHIL 181) with Aristotle's claim that we become virtuous by acting as if we already are. She traces how Aristotle's method converts normative laws, statements of how we should act, into descriptive laws, statements of how we actually do act, and asks what practical techniques might turn deliberate, reflective virtuous behavior into automatic habit. The lecture moves through three sections: norms and habits, Aristotle's theory of habituation, and a comparison with Pavlovian classical and operant conditioning. Gendler draws out parallels between animal training, effective parenting strategies, and the ancient project of acquiring virtue through repeated practice. Recorded at Yale in spring 2011, the talk is chalkboard-and-podium plain, carried entirely by the argument and Gendler's own clear pacing through the material.