This is the author's accepted manuscript.The original publication is available at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9186646&fileId=S0266267114000030.This paper presents Sen's theory of agency, focusing on the role of commitment in this theory as both problematic and potentially illuminating. His account of some commitments as goal-displacing gives rise to a dilemma given the standard philosophical theory of agency. Either commitment-motivated actions are externally motivated, in which case they are not expressions of agency, or such actions are internally motivated, in which case the commitment is not goal-displacing. I resolve this dilemma and accommodate his view of commitment as motivation by develo...