The chapters contained in this dissertation are three essays on the nature of practical authority, and the role it plays in the thought and action of those subject to it. In chapter 1, I criticize a recent and influential philosophical theory of authority, Joseph Raz's service conception, and argue that it is inadequate because it does not recognize that authority thwarts an obedient subject's ability to express her personality and character traits in action. In chapter 2, I argue that, in cases of personal authority, the issuing of a command involves the authority supplying the content of an intention to act to the subject, and that this breaks down the self-other asymmetries which theorists of self-knowledge have assumed exist with respect to the 'privileged access' one is said to have to one's own mind. In chapter 3, I argue that in cases of both personal and non-personal (e.g., institutional) authority, there is a further problem in exercising and obeying authority which has gone unrecognized. I draw on recent work in social psychology to show that authoritative directives fix a subject's understanding of her own actions across time and thus thwart the otherwise dynamic process of the development of the subject's self-conception. I show that these arguments constitute a new burden in justifying authority and therefore revive the anarchist objection that authority and autonomy are conceptually incompatible.