Abstract
Legitimate authorities provide pre‐emptive reasons for action, in that the reasons they provide are not to be added to all other relevant reasons when assessing what to do, but should exclude and replace some of those other reasons. Furthermore, legitimate authorities are dependent in the sense that they ought to issue directives that are based on reasons applying independently to the subjects of the directives. The pre‐emption thesis and the dependence thesis are closely related to the normal justification thesis, which states that the normal justification for authority involves showing that the alleged subject is likely to comply better with reasons applicable to him if he accepts the authoritative directives rather than trying to follow the reasons directly. The chapter ends with a discussion of the nature of the explanatory‐normative reasoning employed in the book.