I was led to your blog by a Google search for "moral objectivity," and enjoyed what I read very much.
A couple questions, which you are free to ignore or answer at time and inclincation permits. First, as a fan of C.S. Lewis, is it safe to conclude you are also a Christian?
Second, as one who knows much of C.S. Lewis (having written a book and named a blog centered on his thinking), do you know of any philosophers/writers who weren't believers in a religion per se who advocated a moral objectivism?
I'm a budding student of intellectual history and I'm thinking of focusing my master's thesis on this very topic - moral objectivity outside of revealed religion.
Anyway, if you have any insight where I might find more about this topic, I will be grateful for your input.
Thanks again for the great blog.
The tradition of moral objectivity goes all the way back to Plato. Plato's Greece did not possess the idea of monotheism, and so Plato's commitment to moral objectivity involves a belief in the Form of the Good and then our having somehow perceived the form of the good in a prior existence. So his version of moral objectivism involves some metaphysics that modern naturalists would not be happy with, but it does not entail theism. Arisotle, who altered the doctrine of Forms but did not abandon it, certainly believed in objective moral values. Hume, it can be argued, is actually a moral objectivist, because although he thinks we get our ethics from sentiment rather than reason, he also seems to think that sympathy gives us a connection to moral truth that, say, sadism does not. G. E. Moore would have to have been a moral objectivists, as would Bertrand Russell in the early days (though he of course became an ethical subjectivist later one). In the debate between William Lane Craig and Douglas Jesseph Jesseph, the atheist in the debate, accepted moral objectivity and thought it could be given a secular foundation.
I think Christianity requires moral objectivity, and I think theism makes more sense of it than atheism does. But atheists are really divided on the issue. If you are a moral objectivist, you are ontologically committed to two types of truths; truths about what is, and truths about what ought to be. Even if an atheist has no trouble accounting for the first class of truths, how the second class of truths can exist if the world is, say, the way the materialist says that it is; it gets even more serious when we realize that somehow this second set of truths has to be relevant to moral behavior. I think God is the best explanation of all of that, but if I were to become an atheist, I think I would still believe in moral objectivity.
Lewis wrote a whole book in defense of moral objectivity, The Abolition of Man, without talking in any way about its foundations in revealed religion. Here's a link to it on Amazon.