 The variety of contexts in which the concept of autonomy functions has suggested to many that there are simply a number of different conceptions, and that the word simply refers to different elements in each of those contexts (Arpaly 2004). Others have claimed that while there may be a single over-arching concept of autonomy, we should think in terms of separable dimensions of it rather than an all or nothing idea (Mackenzei 2014 and Killmister 2017). Feinberg has claimed that there are at least four different meanings of “autonomy” in moral and political philosophy: the capacity to govern oneself, the actual condition of self-government, a personal ideal, and a set of rights expressive of one’s sovereignty over oneself (Feinberg 1989). One might argue that central to all of these uses is a conception of the person able to act, reflect, and choose on the basis of factors that are somehow her own (authentic in some sense). Nevertheless, it is clear that formulating a “theory” of the concept will involve more than merely uncovering the obscure details of the idea’s essence, for autonomy, like many concepts central to contentious moral or political debate is itself essentially contested. So a theory of autonomy is simply a conceptual model aimed at capturing the general sense of “self-rule” or “self-government” (ideas which obviously admit of their own vagaries) and which can be used to support principles or policies the theory attempts to justify.