Almost everyone has wondered at some time or another why morality requires what it appears to require and how, if at all, it speaks to us. In "Ethics: Twelve Lectures on the Philosophy of Morality, " David Wiggins surveys the answers most commonly proposed for such questions-gathering insights from Hume, Kant, the utilitarians and the post-utilitaritarian thinkers of the twentieth century. The view of morality he then proposes draws not only on Hume but on other sources as diverse as Aristotl...