This chapter shows how a proper understanding of the concepts of liberty and autonomy is relevant to questions regarding the justification of compulsory treatment in the context of mental health nursing. Philip Ross proposes that the notion of "rational autonomy' provides a "locus of unity' for health-care work, that is to say, this provides an explanation of the point and purpose of health-care work. This seems a plausible claim in the light of the view that much health-care work involves fostering and enhancing the rational autonomy of patients and clients.