When we think of rules for conduct, we naturally think first of the moral or legal domains, of interpersonal rules, the topics of the previous and next chapters. But individuals sometimes adopt rules for their own conduct for prudential reasons, and I will address the need for such rules in this chapter. Robert Nozick has argued that intrapersonal or prudential rules play an essential role in persons' lives. His argument is reminiscent in significant ways of the strongest argument for interpersonal rules. But there are important disanalogies that will be brought to light in this chapter. They relate mainly to the ability to adopt strategies to optimize, as opposed to settling for the second-best strategy of genuine rules. In view of these disanalogies between the intrapersonal and interpersonal cases, I will again reach a mostly skeptical conclusion regarding the need for genuine prudential rules, this time with only one exception.

I will then consider two special cases of higher-level prudential rules that have been widely assumed to be sound, and I will again question this assumption. The first is a rule to optimize, or maximize, the satisfaction of our rational preferences. I will clarify the sense in which this indeed defines prudential rationality, despite recent denials in the literature, as well as the sense in which it is not an acceptable action-guiding rule. The second higher-level rule to be considered is a prudential requirement to be moral.