"A Moral Argument" in Passionate Conviction, eds. Paul Copan and William Lane Craig (B&H Publishing: Oct 1, 2007), p.85.
Yes, many naturalists deny that objective moral values exist — that our moral impulse is nothing more than the product of a blind evolutionary process that selects out traits that enhance survival and reproduction. I such a case, morality is merely subjective. However, non-theists can and do endorse objective moral values — that rape or child abuse is wrong. These nontheistic moral realists will tell us, "You don't need God to be good." Yet the deeper question is, how did we come to be morally responsible, rights-bearing beings? Since all human beings are God's image-bearers, they not surprisingly recognize the same sorts of moral values theist do. The basic issue, tough, is this: why think humans have rights and dignity if they're products of valueless, physical processes in a cause-and-effect series from the bing bang until now? The more plausible context or scenario is that human value and moral responsibility come from a good God who created us as intrinsically valuable, morally responsible creatures.
G. E. Moore, original 1903 (Barnes & Noble: January 2005), 264 pages.
When Principia Ethica appeared, in 1903, it became something of a sacred text for the Cambridge-educated elite who formed the core of the Bloomsbury Group. In a letter of October 11, 1903, Strachey confesses to Moore that he is "carried away" by Principia, which inaugurates, for him, "the beginning of the Age of Reason." Moore's critique of convention, his caustic dismissal of his philosophical predecessors, and the relentless rigor of his method promised a revolution in morality commensurate with the modernist transformation of art and literature. Principia Ethica shifted the study of ethics away from normative questions to issues of "metaethics," the study of ethical concepts.