As originally used, the term ‘autonomy’, so central to bioethical debate, had nothing to do with health care or indeed with individuals. Rather, the term described the right of Greek city-states to self-government. With the Enlightenment, the principle of autonomy came to be associated with individuals as well as states and respect for autonomy now provides the philosophical underpinning for much of bioethics and law. While this book is concerned with autonomy in the relatively limited sphere of decisions about treatment, the status to be accorded to individual autonomy is central to many bioethical debates, ranging from access to euthanasia and reproductive technology to the sale of organs or body parts.

Although the importance of autonomy to healthcare ethics and law is clear, what the principle actually means is less so. As Gerald Dworkin notes, ‘[a]bout the only features held constant from one author to another are that autonomy is a feature of persons and that it is a desirable quality to have’. In fact, as this chapter shows, the concept of autonomy is more dynamic and complex than is sometimes appreciated in legal discussions of its role in healthcare decision-making. This chapter establishes the theoretical foundations for the legal discussion which follows in later chapters by exploring autonomy as a philosophical construct within ethical debate. This is important not least because, as Alasdair Maclean notes, the law tends to follow the dominant ethical arguments although with an extensive time lag.