This chapter focuses on identifying, and discussing, some of the possible conceptual sources of the emphasis placed on autonomy in the academic medical law literature. Autonomy in Immanue Kant's ethical theory is therefore bound up with obligation and imperatives - one must act in accordance with practical principles of the will. The chapter focuses on what T. L. Beauchamp and J. F. Childress have to say about autonomy and its meaning, both generally and, more specifically, in the context of bioethics. It contrasts Beauchamp and Childress's approach to autonomy with that which can be derived from the work of two medical ethicists, John Keown and Luke Gormally. The concern with right and wrong, and with identifying foundational moral principles, that drives Keown and Gormally's work is of limited use to any attempt to grasp how autonomy exists within specific institutional settings or social practices.