Abstract
The concept of autonomy plays a central role in bioethics,1 but there is no consensus as to how we should understand it beyond a general notion of self-determination. The conception of autonomy deployed in applied ethics2 can have crucial ramifications when it is applied in real-world scenarios, so it is important to be clear. However, this clarity is often lacking when autonomy is discussed in the bioethics literature. In this paper we outline three different conceptions of autonomy, and argue that a substantive, perfectionist approach meets the theoretical requirements for an account of autonomy and also provides practical guidance. As Rebecca Walker argues, bioethics requires a more conceptually adequate account...