Perry insists that non-religious beliefs in human rights are fatally flawed because they cannot be grounded. Religious believers do not suffer from this flaw, and therefore possess a superior foundation for human rights, he argues, because belief in God supplies the necessary foundation. But if my argument is correct, the foundation for the religious moral system is not belief in God, but the actual fact of God’s existence. Since the fact of God’s existence has never been established—and remains the impenetrable uncertainty of our existence—religious moral systems likewise operate without a grounding, for they cannot establish their foundational assumption.
Tamahana doesn't say as much, but it seems to me that Perry is trying to have his cake and eat it too: he wants his argument to rest on something else other than the existence of God so he can avoid Tamahana's charge, but what system of morality would rest on an illusion about God's existence? If events were to prove that God did not exist, would morality collapse? Probably not, as Tamahana's example helps make clear:
Perhaps a simple thought experiment can help. Imagine that your longstanding belief in God is destroyed owing to some precipitating event (say, an inexplicable, arbitrary, unjust, tragedy happens to a family member). In the dark of the night, you come to the conclusion that you no longer believe in God. The next day, when you venture into the world, will you suddenly feel tempted to freeload off your friends, cheat strangers, stop taking care of your children, or steal from, rob, rape, or kill someone? Of course not. You considered all of these things immoral the day before, and you will still see them as such. You may well experience the throes of an existential crisis (asking yourself what matters in life), but that will not of itself penetrate or dissolve your routine moral beliefs.
Even a devout Christian would have trouble arguing with this proposition.
The problem with Perry's argument and all others that echo it, is that it assumes a moral superiority on the part of the religious believer that simply doesn't exist, as events around the world throughout human history have shown us. If the religious wish to believe that their faith in God underlies their morality, so be it. But it must be acknowledged that for the atheist, morality can be just as vital. The devoutly religious fear this fact for it undermines the necessity of God, but it is a fact no less.