On God and Objective Moral Values, One More Time
The best explanation for our mutually shared basic morality is that it helps us get along in our respective cultures better than not having it. All you have to do is consider what a society would look like without this mutually shared basic morality. To be in a society demands that we have moral rules for living, so morality is forced upon us. We have no choice if we want to live in a society, any society, and we are by nature social beings who need one another. In some ways it’s better to have bad moral rules than none at all, for then we at least know what is expected of us. We’ll have moral rules whether we like them or not, whether we agree with them or not, and whether they can be justified or not. But guess what? As social beings we overwhelmingly agree on some important basic moral rules. Folks, this is not surprising in the least.
The fact that we agree on basic moral rules is completely consistent with cultural relativism. We wouldn't expect there to be complete moral disagreement between us simply because we are describing the adopted moral rules of the same species, human beings. We have evolved to have the same needs and wants. If cultural relativism is the case then this also explains why philosophers have so much trouble coming up with ethical theories that can justify human morality. I taught ethics in college classes and there are some serious intellectual difficulties with every ethical theory, except for one, cultural relativism. In other words, there is nothing internally inconsistent with cultural relativism. We may not like the conclusion but that's not a reason to reject it. [No, it does not reduce to individual relativism either. That is a non-sequitur, simply because we are by nature social beings who need one another.] But just like with social contract theories, cultural relativism offers no specific guidance as to which moral rules a given society should adopt either.
Since morality evolves with the human species I am tentatively embracing Michael Shermer's principle for morality based in democracy, which is to simply ask the people affected, with science leading the way. Why can't science inform us of what makes human beings happy? What's the alternative? Faith is no answer. With faith anything can be justified.