Here’s the Pope, speaking on his recent trip to Brazil:
Where God is absent — God with the human face of Jesus Christ — these [moral] values fail to show themselves with their full force: nor does a consensus arise concerning them.
I do not mean that nonbelievers cannot live a lofty and exemplary morality; I am only saying that a society in which God is absent will not find the necessary consensus on moral values or the strength to live according to the model of these values.
I think the Pope gets his causality backwards. Human morality is largely a product of natural selection, not religion. It depends on our instinctive emotional reactions to situations that involve hurting another person. (I’ve written about this before.) According to scientists, when we think about hurting somebody else (like pushing a man onto trolley tracks), we automatically generate a visceral set of negative emotions, which discourage us from behaving in immoral ways. As Joshua Greene has noted, “Our primate ancestors…had intensely social lives. They evolved social mechanisms to keep them from doing all the nasty things they might otherwise be interested in doing. This basic primate morality doesn’t understand things like tax evasion, but it does understand things like pushing your buddy off of a cliff.” Our moral reactions are simply side-effects of natural selection, the necessary consequence of monkeys living in a group.
Of course, this is a blasphemous idea. Religious believers assume that God invented our moral code. It was given to Moses on Mount Sinai, a list of imperatives inscribed in stone. (As Dostoevsky put it, “If there is no God, then we are lost in a moral chaos. Everything is permitted.”) But this cultural narrative, which is promulgated by people like the Pope, inverts the causality. Our moral emotions existed long before Moses. They are writ into our primate mind. Religion simply allows us to codify these intuitions, to translate the ethics of evolution into a transparent legal system. Just look at the Ten Commandments. After God makes a series of religious demands – don’t worship idols and always keep the Sabbath – He starts to issue his moral orders. The first order is the foundation of primate morality: Thou Shalt Not Kill. Then comes a short list of moral adjuncts, which are framed in terms of harm to another human being. God doesn’t just tell us not to lie; He tells us not to bear false witness against our neighbor. He doesn’t prohibit jealousy in the abstract; He commands us to not covet our neighbors “wife or slaves or ox or donkey.” The God of the Old Testament understands that our most powerful moral emotions are generated in response to personal harm, so He forces us to imagine personal scenarios. We hate hurting each other, and that is what the Ten Commandments tell us not to do. God is simply regurgitating our most natural moral instincts.
So religion didn’t invent morality. Nevertheless, it still played an important historical role in helping humans legislate their moral intuitions. The ten commandments explained our own primate own morality to us. Of course, now that we have secular legal systems, religion is no longer a necessary part of the moral order. As the Pope himself admits, even atheists can still act in a moral manner.