You: A society which practiced morality of convenience would be indistinguishable from our own. Our system of morality seems works, and if it did not our society would have modified itself or died out long ago.

Aaron: I agree that immoral societies are doomed to die out, but that does not prove that moral societies are not guided by the hand of God.

You: It also does not prove that moral societies were inspired by God. Because there is a process by which moral societies survive and immoral ones die that needs no help from God, it is simpler and therefore preferable.

Aaron: Preferable to you, perhaps.