  An agent is one who acts. In order to act, one must initiate one’s action. And one cannot initiate one’s action without exercising one’s power to do so. Since nothing and no one has the power to act except the agent herself, she alone is entitled to exercise this power, if she is entitled to act. This means that insofar as someone is an agent, i.e., insofar as she is one who acts—she is correct to regard her own commitments to acting, her own judgments and decisions about how she should act, as authoritative. Indeed, if she were to challenge the authority that is an essential feature of her judgments and decisions, then they would cease to be her own practical conclusions. Their power to move her would cease to be a manifestation of her power to move herself; it would not be the power of her own agency.