First published in 2002. This is Volume V of seven in the Library of Philosophy series on the Philosophy of Religion. The Library of Philosophy was designed as a contribution to the History of Modern Philosophy under the heads: first of Different schools of Thought - Sensationalist, Realist, Idealist, Intuitivist; secondly of different Subjects - Psychology, Ethics, Aesthetics, Political Philosophy, Theology. Written in 1961, this is an essay the Theological Frontier of Ethics given as lectures in the University of Birmingham.