In this chapter we shall examine two moral theories each of which offers its own distinctive, and supposedly over-arching, moral principle. These are not the only moral theories which philosophers have put forward, but we concentrate on them because the principles they offer are clearly addressed to individuals, and intended as a basis for decisions as to what is the right thing to do in any particular situation. This chapter thus gives some insight into moral theory and also the opportunity to practise the skill of applying principles to specific cases. You may wish to increase your knowledge of moral theory by studying two other important theories – the social contract idea of John Rawls (J. Rawls, A Theory of Justice , Cambridge: Harvard University Press, 1971), which was mentioned in Chapter 5 in relation to the concept of rights, and the idea of ‘virtue ethics’, dating from Aristotle, which emphasises the importance of good character, and which is briefly discussed in James Rachels’ The Elements of Moral Philosophy, McGraw-Hill, 1993. We shall not cover these theories in detail because ‘virtue ethics’ does not offer a single clear principle, and although Rawls theory includes principles of justice, these are intended as a basis for social organisation rather than a basis for individuals to make their ethical decisions.