Medical law and ethics students are normally taught that mental capacity is a key concept. Simply put, if the patient has capacity then their autonomous decisions are respected, while if they lack capacity then decisions are made on their behalf based on what is in their best interests. This paper will challenge that supposition and claim that only in rare cases does it matter in terms of the outcome whether a patient has capacity or not. The paper will then turn to the ethical issues. While the importance of capacity is commonly said to rest in respect for autonomy it will argued that autonomy offers little help in complex legal cases. None of this is to say we should not be respecting the views of patients, but that autonomy and capacity are an insecure basis for doing so.

Respondent: Dr Jonathan Pugh (Faculty of Philosophy, University of Oxford)