Why? Because the argument that “Without God, there is no basis for morality,” does nothing at all to prove that a god exists. At best, it’s an argument to want a god to exist. But just wanting something, no matter how much you might want it, does not make it true. The universe does not owe us an objective moral basis, and therefore the proposition that objective morality cannot exist without a god doesn’t demonstrate that a god exists.
So what happens if you convince somebody that there’s no moral basis without God, if you haven’t separately convinced him that there is a god? You take someone who had previously been moral, and turn them into someone amoral? Who actually wins in that situation? Anyone?
See, here’s the thing. By and large, atheists don’t look for ways to construct moral systems independent of God because we think they will banish him. We already don’t believe he exists. We try to construct moral systems because they are necessary to live in a society, humans by and large thrive best in societies, and nobody but humans is going to construct those societies (or the morals that guide them) for us. We don’t construct secular moral systems to deny God, we construct secular moral systems because we have no other choice.
And having to deal with the realities of living with other people seems like a pretty decent basis for a morality to me.
But ultimately I don’t think that the debate is necessarily about whether any given atheist can be a moral person. Inevitably, the debates seem to come down to this: how does an atheist justify imposing his morality on those who do not share it, since (as the theists claim) any moral system not based on a supreme authority is just as valid as any other?
From here on out, I’m speaking only for myself. Though my thoughts have been influenced by others, I cannot say that they are necessarily those of any significant number of atheists (who tend to be a diverse lot with a number of strongly conflicting opinions). But to me, it seems like the question posed in the preceding paragraph has some assumptions built into it that I do not believe are justified.
Firstly, the question seems to assume that morality is a fixed thing, and therefore when two moralities come into conflict one must be imposed unchanged on the other.
Secondly, it seems to assume that without a supreme authority, there is no basis for evaluating whether one moral choice is better than another.
I simply do not agree with either assumption.
To address the second one first, I do not believe that morality has anything to do with pleasing or obeying an authority figure in the first place. Morality is about how your behavior affects other people (and, to a certain extent, other living things). Once you understand that morality isn’t about rules, but about people, then it’s easy to see how there is a basis for judging whether certain moral choices are better than others.
To address the first assumption, when conflicts arise it may seem in some situations where it is clearly obvious that one path creates better outcomes for the affected people, then it may be necessary to impose that path. But often it’s less clear, which is why the morally responsible thing to do is be open to the possibility that your moral preference may be the one that’s wrong. Or that there’s enough ambiguity that imposing one or the other is not justified.
That’s the part I think is the hard one to convey. The idea that you can be wrong, or even that there might not be a clearly obvious right thing to do in all situations. That imposing your moral preferences, no matter how strongly felt they are, may not always be justified. And also accepting that the mere fact that you can’t know the absolute most right answer in every situation does not mean you can’t make a good decision. And more than that, it’s OK for that to be the case.
If you insist that morality is based on following the rules of some ultimate authority, then you have surrendered the ability to change those rules even when they demonstrably create awful outcomes for actual people. Following rules that create misery simply because an authority tells you to is, in my opinion, a fairly immoral stance. Particularly when that authority is one that can’t even be demonstrated to exist, or to have the best interests of any people whatsoever in mind.
We’re human. We’re fallible, but we’re also learning. We do the best with what we know now, in the hopes that in the future we’ll be able to do better based on the knowledge we’ll have then.