The book arrived yesterday via Amazon and I began reading it this morning. Looks good!
Oxford University Press, 2001. Foot essays "a naturalistic theory of ethics: to break really radically both with G. E. Moore's anti-naturalism and with the subjectivist theories such as emotivism and prescriptivism that have been seen as clarifications and developments of Moore's original thought." (p. 5)
Here is a review.