My view is that objective moral properties exist and that they would be unexpected, and indeed inexplicable, in a world in which atheism (or more precisely, naturalism) is true.It's likely that's the view of many theists. I have certainly seen similar sentiments expressed by theists on blogs and in debates. But is it true? And even more to the point, isn't such an argument self-defeating?
In order to get around Euthyphro (and indeed to have any chance of alleged moral facts being "objective"), theists will seek to ground moral facts in God's nature. That is to say, to ground it in characteristics or essence that is NOT subject to God's whim or will.
Fair enough (and it seems to me that this is the only possible successful answer to Euthyphro's dilemma). However, in what way is this functionally different than a non-theist's claim that moral facts are grounded in the nature of existence? I.e., in brute fact (that's just the way things are)? The question "why is God as He is?" is functionally the same as "Why is existence as it is?" Moral facts grounded in the nature of existence would therefore seem to be ontologically equivalent to those grounded in the nature of God.
What therefore could serve as any relevant difference between "God" and "existence" that could satisfy Hawthorne's condition such that the existence of moral facts would be "unexpected" and "inexplicable" if God were NOT to exist? The only difference appears to be will or intent, yet that is specifically what we must rule out if we want moral facts to be objective. So doesn't it seem self-defeating to argue that "objective" moral facts only make sense if they're the product of will or intent, thus rendering them non-objective?
(Also posted as a comment at DC)