Deliberation issues in decision, and so might be taken as a paradigmatic volitional activity. Character, on the other hand, may appear pre-volitional: the dispositions that constitute it provide the background against which decisions are made. Bernard Williams offers an intriguing picture of how the two may be connected via the concept of practical necessities, which are at once constitutive of character and deliverances of deliberation. Necessities are thus the glue binding character and the will, allowing us to take responsibility for our characters. Intriguing though the picture may be, it did not receive a thorough elaboration in Williams’s work. My aim here is to work out and defend what I take to be the most valuable aspect of Williams’s view of agency: its model of the way character and the will can jointly determine agency through mutual constitution. However, I argue that Williams’s attempt to use this model to ground his attack on Kantian morality does not succeed, because the primacy Williams accords to character over the will cannot yield the appropriate kind of normative authority, even from the perspective of the agent. I urge that we retain Williams’s model of the interaction between character and the will, modified to allow the will an authority that is not derived from the necessity of character.