The moral problem of authority is the challenge of reconciling legitimate authority (the right to rule) with the demands of freedom and rationality. In this book, I argue that authority can have legitimacy, but when it does it generates a moral dilemma, where the obligation to obey comes at some cost to freedom and reason. Hence, not only do I depart from the views of those who insist that authority can never have legitimacy, but also those who maintain that insofar as authority is legitimate it simply satisfies the demands of freedom or rationality. My focus here will be on both what it is that justifies authority (in particular focusing on membership, and the goods of membership) as well what type of reason an authoritative directive is, how it can come into conflict with others reasons, and how those conflicts are resolved.