What, then, is driving the rejection of the truth of moral absolutes? Bad arguments, many of which I shall discuss. But they are so many, and so poor, that one cannot but speculate about other motivations. These seem easy enough to find and understand. Pastoral considerations: lightening the burden when norms are conceived of—not as truths about service of goods which will be found again, transfigured, in the final Kingdom—but as laws imposed on freedom by fiat in the interests of some divine obstacle race, with rewards dubious (if any) and related merely extrinsically to the content of one's choices . . . ; personal considerations: we all are sinners and would like to consider ourselves not so; the Enlightenment psychopathology of progress illustrated earlier . . . ; and, in general, a loss of the sense that revelation was completed in the life, the words, and the deeds of Jesus, communicated to and handed on by the apostles as a gospel which is "the source of all saving truth and all moral teaching" and "includes everything which contributes to the holiness of life . . . of the People of God."
This last is fundamental. To affirm that Bentham, Mill, Marx, and, in his different way, Machiavelli were right in their rejection of the moral absolutes, and that the whole People of God was wrong until yesterday in accepting them as truths integral to salvation (ultimate and integral human fulfillment itself), and that the church's magisterium is wrong in proclaiming their truth to this day, is to take a long step toward denying that God has revealed anything to a people, or ever constituted a people of God at all.
(John Finnis, Moral Absolutes: Tradition, Revision, and Truth [Washington, DC: The Catholic University of America Press, 1991], 29-30 [ellipses added; footnote omitted])
Note from KBJ: Finnis is playing with fire when he seeks to explain why people reject moral absolutes, for those who reject moral absolutes (I'm one of them) can seek to explain why Finnis accepts moral absolutes. (The explanation, I assure you, will not be pretty.) There is all the difference in the world between explanation and justification. To explain why someone believes something is to go no way toward undermining (or supporting) that belief; so why not stick to justification? Certainly no philosopher should care about explanation. Leave that to the scientists, or to common sense.
Keith Burgess-Jackson, J.D., Ph.D. 