See: Good, Evil, Morality, and Ethics: "What would it mean to want to be moral (to do the moral thing) purely for the sake of morality itself, rather than for the sake of something else? What could this possibly mean to a scientific materialistic atheist? What is this abstract, independent, pure morality? Where does it come from? How can we know it? I think we must conclude that morality is a means, not an end in itself."