Originally published in 1988, this landmark study develops its own positive account of the nature and foundations of moral judgement, while at the same time serving as a guide to the range of views on the matter which have been given in modern western philosophy. The book addresses itself to two main questions: Can moral judgements be true or false in that fundamental sense in which a true proposition is one which describes things as they really are? Are rational methods available in ethics which can be expected to produce convergence on shared moral views on the part of those who use them intelligently?