Does morality depend on religion? In Plato's early and fun (and short!) dialogue Euthyphro, Socrates questions Euthyphro (who's on his way to go and file murder charges against his own father) about the meaning of "piety." Is an action (like turning in your dad) pious because it's the kind of thing that the gods love? In modern terms, are pious actions justified just because of the commands (or, more in the absence of specific commands, the attitudes) of God? Socrates argues that this isn't the case: conceptually, "good" doesn't depend on these commands or attitudes of God; it's rather that God (or "the gods," taken together re. whatever they might all agree about) desires of us the actions He does because those actions are good.
Mark and Seth are joined by Dylan and by our former U. of Texas classmate Matt Evans, currently an associate professor of philosophy at the University of Michigan, to lay out the dialogue and discuss the extent to which it actually bears on this more modern debate about the relation of morality and religion. A divine command theorist argues, contra Plato, that since God is omnipotent, there's no sense in which morality can be metaphysically prior to his commands (or his disposition, or his nature). On the other side (which is, you should note, also a theist side, Swinburne being a good example), to avoid morality being an arbitrary matter depending on God's whims (meaning he could have declared child torture to be good), a Platonist would argue that like the laws of logic, fundamental moral truths have to come first in some sense: God only commands right actions because He recognizes them to be right; they don't magically become right just because he says so.
Is this just a dispute internal to religion? No. If Plato is right, then this means we can legitimately theorize about moral truths independent of reference to God; we don't even have to assume there is (or isn't) a God. Theists and atheists are thus able to have a productive ethical discourse based on a common ground, and religious people who claim that atheists aren't or can't be moral are stymied good and hard.
Seth recommends the Wikipedia entry on the Euthyphro dilemma. Some of the last part of our discussion focused on the place of the dilemma in Judaism. For a good, Swinburne-esque discussion, listen to this Conversations from the Pale Blue Dot interview with David McNaughton.