 As should be clear from this short discussion of the history of the idea of free will, free will has traditionally been conceived of as a kind of power to control one’s choices and actions. When an agent exercises free will over her choices and actions, her choices and actions are up to her. But up to her in what sense? As should be clear from our historical survey, two common (and compatible) answers are: (i) up to her in the sense that she is able to choose otherwise, or at minimum that she is able not to choose or act as she does, and (ii) up to her in the sense that she is the source of her action. However, there is widespread controversy both over whether each of these conditions is required for free will and if so, how to understand the kind or sense of freedom to do otherwise or sourcehood that is required. While some seek to resolve these controversies in part by careful articulation of our experiences of deliberation, choice, and action (Nozick 1981, ch. 4; van Inwagen 1983, ch. 1), many seek to resolve these controversies by appealing to the nature of moral responsibility. The idea is that the kind of control or sense of up-to-meness involved in free will is the kind of control or sense of up-to-meness relevant to moral responsibility (Double 1992, 12; Ekstrom 2000, 7–8; Smilansky 2000, 16; Widerker and McKenna 2003, 2; Vargas 2007, 128; Nelkin 2011, 151–52; Levy 2011, 1; Pereboom 2014, 1–2). Indeed, some go so far as to define ‘free will’ as ‘the strongest control condition—whatever that turns out to be—necessary for moral responsibility’ (Wolf 1990, 3–4; Fischer 1994, 3; Mele 2006, 17). Given this connection, we can determine whether the freedom to do otherwise and the power of self-determination are constitutive of free will and, if so, in what sense, by considering what it takes to be a morally responsible agent. On these latter characterizations of free will, understanding free will is inextricably linked to, and perhaps even derivative from, understanding moral responsibility. And even those who demur from this claim regarding conceptual priority typically see a close link between these two ideas. Consequently, to appreciate the current debates surrounding the nature of free will, we need to say something about the nature of moral responsibility.