Nurses, like many other professional and semiprofessional groups, have a code of conduct. This raises important philosophical questions about the point of including nursing ethics in nursing education and about the content and methods of such teaching. This paper identifies seven functions that might be fulfilled by professional codes; it discusses the philosophical issues these raise and the implications for teaching professional ethics. It is argued that, far from codes rendering the teaching of ethics unnecessary, they provide additional reasons for its inclusion. An enhanced ability to make moral decisions helps to overcome the shortcomings of the codes, enables a profession to be autonomous in the development of its code, enables individuals to be authentic moral agents, and is essential in matters concerning the disciplinary function of the codes. The role of emotions, feelings and attitudes in ethics also presents philosophical problems that moral education can help to resolve.