While reading some remembrances of Christopher Hitchens, I came across a column which quoted this statement from his brother Peter, who was a believer:
Like Einstein, he viewed ethics as "an exclusively human concern with no superhuman authority behind it," a position that sparked conflict with his journalist brother, Peter, who has argued that, "For a moral code to be effective, it must be attributed to, and vested in, a nonhuman source. It must be beyond the power of humanity to change it to suit itself."
Since Christopher Hitchens isn't around to answer this, I guess it's up to me.
So, here's what I say to Peter Hitchens and anyone who believes likewise: The fatal flaw in this position is that, contrary to your confident presumption, there is no non-human moral authority. Every religious book is written, edited, and printed by humans. All moral opinions, interpretations, and proclamations are human opinions. If there were a huge, glowing set of tablets with commandments engraved on them that descended from the sky accompanied by angels blowing trumpets, and the choice was between following those or making up moral laws on our own, we'd be having a very different debate; but there is no such thing. All moral laws are humanly produced. The question is which set of human-created laws we should follow and why.
This clearly isn't the terrain that religion wants to fight on. They want to begin the debate with the presumption that their moral rules are supernaturally inspired, given to us by a source beyond human comprehension, and that no human being is qualified to argue with them. Clearly, such an enormous claim has to be proved, not just assumed.
Even if one is a theist, there's no reason to grant this presumption. There are thousands of different religions in the world, each with their own, mutually incompatible moral codes, and each one claiming supernatural sanction. Even if you believe in a god who gives moral revelations, the odds of any one claimant being the beneficiary of such a revelation is small. No matter what, the apologist who wants to claim divine warrant can't escape the need to give direct evidence of supernatural influence in the production of his preferred moral code. Mere appeals to faith, which is all that they have to offer, are a poor and inadequate substitute.
I agree that belief in a divine origin makes moral ideas harder to change. But that's only a good thing if those ideas are themselves good - and many religious ideas manifestly are not. The "non-human authority" that Peter Hitchens appeals to is the same non-human authority that was invoked (and still is invoked) in support of absolute monarchy, of slavery, of genocide, of patriarchal demands for women's submission, of racial segregation, of anti-gay prejudice, of the diminution of reason and free inquiry. Precisely because all these ideas were claimed to come from a non-human source, it was and is much harder to change them than it otherwise would have been.
Of course, there are many religious people today who recoil at these horrors. And that just proves the point: every moral code, whether theistic or atheistic, changes over time. The only question is whether we admit this or whether we pretend that we're not doing it. Churches almost always choose the latter course, which leads to absurdities like the Bible verses regulating slavery being swept under the rug and ignored, even while apologists that nothing in their doctrine has ever changed. They would be much better off if they'd simply admit that human conscience has shown these passages to be detestable, that their holy books contain moral errors, and then join the rest of us living in the real world and using our reason to figure out how we can act to achieve the greatest good.