<bold>Part Three</bold> examines the development of Beauchamp and Childress 'four principles' approach to medical ethics from the 1<super> st</super> to the 6<super>th</super> Editions of <italic>Principles of Biomedical Ethics,</italic> arguing that it has, thanks to changes in the authors' conception of philosophical moral theory, been able to productively incorporate the views of many of its critics over this time; that it is also able to incorporate features of different ethical approaches such as virtue ethics, narrative ethics and ethics of care; and that, properly understood, it continues to provide a good framework both for moral reflection in medicine and the provision of concrete action-guides. The thesis concludes by considering this view of the four principles in the light of the earlier sections' approach, and attempting to demonstrate further demonstrate their value through two case-studies.EThOS - Electronic Theses Online ServiceGBUnited Kingdo