Classically, the ambition of legal regulation is to change behaviors. Legal regulation can accomplish its goals directly, through fear of sanctions or desire for rewards. But it can also do so indirectly—and often more cheaply and effectively—by changing attitudes about desired or undesired behaviors. Though moral attitude change is promising, it is also perilous. This chapter reviews the ways in which law aims to change moral attitudes. It also reviews the ways in which it can go awry, and offers predictions about when attempts at moral attitude change will succeed, and when they will fail.