If there is not a divinely prescribed code of morality, reinforced by reward or punishment in the afterlife, then why be good? Why not do any damn thing one pleases?
We hear this argument a lot, particularly in this politically-charged season when religious fundamentalism appears to wield an inordinate amount of influence, at least on one side of the political divide.
What about reason? Can reason prescribe good and bad?
Well, lots has been written on the natural foundations of morality, by people more qualified than me, but let me mention something Benjamin Franklin said in his autobiography: "So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a reason for every thing one has a mind to do."
Bingo! One for the revelationists.
Not quite. Ben Franklin was not one for revelation. Nor was he a champion of metaphysical reasoning. The basis for morality, he believed, is utility. In Poor Richard's Almanack he wrote: "Sin is not hurtful because it is forbidden, but it is forbidden because it is hurtful…Nor is a Duty beneficial because it is commanded, but it is commanded because it is beneficial."
Which seems to me a pretty good explanation why the Golden Rule is so universal across cultures, even among those peoples who weren't privy to the tablets from the mount, or indeed any revelation whatsoever.
(I hear my grammarian mother whisper from beyond the grave: "Than I, Chet, than I.")