A little over a year ago, the Jblog world was abuzz about an article by Rabbi Avi Shafran where he claimed that without G-d we "have no reason to believe in objective categories of good and evil." He argued that absent G-d the world would be
"a place where the very concepts of morality and ethics are rendered meaningless, a world view in which a thieving, philandering, serial murdering cannibal is no less commendable a member of the species than a selfless, hard-working philanthropist."
In other words, without G-d there is no objective morality and everything is a free-for-all.
This argument relies on three important assumptions:
1) That we are capable of determining the content of that morality (the epistemic assumption).
2) That the content of that morality is "better" than any subjective morality (the metaphysical assumption).
3) That we are bound by that objective morality (the normative assumption).
These three assumptions are crucial. If there is an objective morality, but we have no means of learning our duties, then objective morality is useless and we are no better off than if morality was purely subjective. We wouldn't have any way of knowing if killing an infant is objectively good or bad. Furthermore, G-d's objective morality must really be more moral than any system of subjective ethics or it serves no purpose. It might be wrong to kill infants because G-d said so, but so what? It might also be wrong to kill infants because any random person came up with a system of morality. The objectivity of the system is only valuable if it leads to more moral results. Otherwise who cares if morals are objective or subjective?
Moreover, even if objective morality exists and we can discover that objective morality, we must be bound by that morality. If we can choose whether to be bound by that morality, we are no better off than if morality was subjective. Anyone can do whatever he wants.
I posted about this debate when it first happened, and my argument focused on the first assumption. There I argued that even if objective moral principles exist, man must apply to them to real situations and since reasonable people can disagree over how to apply these principles, objective morality is never completely objective. We can never really know what objective morality demands.
Notwithstanding the validity of that argument, I wish to challenge the third assumption here. Let me unpack its hidden premises a little more. The argument that only G-d can create an objective (and therefore meaningful) morality presupposes that we are bound by that Divine morality. It also assumes that moral duties can only exist if they are universal: they must apply to and bind everyone. What does it mean to say that an action is "good" or "bad"? "Good" actions are the ones that uphold a moral duty, "bad" actions are the ones that violate that duty. We have a duty not to murder infants and also a duty to help the poor. People who murder infants violate the former, while charity givers follow the latter.
But in what sense is a person violating a duty if he isn't obligated by it? Am I violating a duty to believe that Jesus is our savior? Or to kill infidels? The fact that a system exists which designates moral categories is meaningless unless I am obligated to follow that system.
So if I am not bound by G-d's moral system, then there is no objective morality in any nontrivial sense. There might be a system that claims to be objective, but so what? Hitler was only wrong (in Rabbi Shafran's view) because he violated his objective moral duty not to kill innocent humans. But if he wasn't bound by that duty, how could he be "wrong?" In that case, morality is inherently subjective in the sense that we are free to choose our moral obligations. If I am not bound by G-d's objective morality, then I can choose my personal subjective morality. So Rabbi Shafran's argument clearly presupposes that we are bound by some independent objective morality that exists apart from G-d's command or else we wouldn't be violating G-d's morality.
Perhaps one could respond that if the epistemic and metaphysical assumptions are correct, then objective morality is actually more moral, and we have an obligation to be moral. But what is the source of that obligation? If we aren't bound by G-d's morality, what obligation do we have to be moral? Some independent objective morality must exist that does not depend on G-d.
So Rabbi Shafran's argument is actually turned on its head. Rather than proving that objective, meaningful morality can only exist because of G-d, it actually presupposes that an independent morality exists without G-d! Without that independent morality, there can exist no useful, G-d given, objective morality. The argument fails on its own premises.