Originally published in 1988, this book discusses if moral knowledge exists, and if so, if it is similar to other forms of knowledge. This book approaches the issues from both historical and contemporary perspectives and in order to determine whether there is a real property of rightness, looks to the ethical theories of Hobbes, Hume and Kant. This historical analysis leads to a systematic comparison of three theories of the nature of ethics: realism, emotivism and coherentism. The nature of coherence is explained using legal reasoning as a model. Moral reasoning is compared and contrasted with reasoning both in science and law, showing how ethics differs from science and empirical disciplines.