A common but quite silly accusation from certain folks is that atheists have no morals, or that we just make up our rules as we go.
In this post I will attempt to explain why atheists are in fact more morally responsible than many non-atheists. I'm pretty sure most non-atheists will disagree, but my purpose is not to convince them, but to have a short-hand way of dismissing those silly accusations.
Morals are rules of behavior. Whether or not we agree on what the rules ought to be, most people do agree that rules exist. Even people who do not agree that the word "morals" has real meaning will agree that people manage to live together in complex societies by establishing rules and convincing at least most people to abide by them.
So there are a couple of ways of coming up with rules of behavior.
On the one hand we can think about the rules, and decide on rules that work well towards a goal. The goal itself is of course also a moral rule which can be chosen randomly. However, it is unlikely that societies whose moral goals are harmful will survive for long. So now we're looking at a number of societies that have chosen moral goals that are helpful to their survival. People in these societies can examine their moral goals and the rules that work towards those goals. They can decide if their rules are consistent with their goal, insofar as the rules deal with human nature and physical reality and how they relate to the goal.
I'll call these people secularists.
On the other hand we can allow the rules to be imposed on us. Thus, most modern non-atheists will say that rules are moral, whether or not their deity says so, but human beings should just follow the rules the deity provides, because the deity would never make an immoral rule. The way you can tell if a rule is from the deity is by checking if it's a moral rule, and if it is then it's from the deity.
I'll call these people panglossians, after Voltaire's character, Dr Pangloss, who satirized Leibniz's optimistic appraisal of the Christian deity.
But the silly accusation doesn't come from the larger body of non-atheists. It comes from a minority body, from people who argue that the moral value of a rule doesn't derive from the rule, but from the fact that the rule comes from the deity. For these non-atheists this is how it works: Their deity decides that a certain rule should be obeyed. Because their deity says so, that rule is automatically moral. There is no consideration of consequences or of human moral goals allowed. If the deity orders a murder, then that murder is a moral act, by definition.
Ronald Dworkin discusses how one might decide if a rule is truly moral or not. He draws an analogy from science. A fact about science depends on the exact configuration of the particles that make up nature - baryons and leptons and bosons. So, he says, maybe a fact about morals depends on the exact configuration of another kind of particle, so far undiscovered, which confers moral value: morons. Yes, he's making a joke.
But people who believe that a rule is moral if and only if it comes from their deity are effectively saying that their deity is such a moron. I'll call these people moronists, and their belief moronism. I have observed it among all faith communities, so I'm not picking on any particular one, even if some of my friends might feel personally addressed.
Moronism is a highly problematic position to take. For one thing, no one has ever measured the value of a moron, so it's hard to say how moronists can know if a rule is moral or not. Their position is that their rules come from their scriptures and from their theologians. However, their scriptures are hardly consistent in the rules they lay out, and it's a plain fact that the scriptures have been used over time to support wildly inconsistent moral rules. That leaves their theologians, who claim to have a special sense for the value of a moron, but even they disagree among each other.
What it all boils down to is that moronists adopt random rules without consideration of their morality, but on the say-so of other moronists. They are essentially following orders, in the best tradition of a concentration camp commander. They are good soldiers, perhaps, but one thing they are not.
Moronists are not morally responsible actors.
Panglossians do a little better. While panglossians will look to their theologians and their scriptures, they do admit the possibility that immoral rules might be just as easily drawn from authoritative sources as moral rules. The main complaint one might have about panglossians is that they bother with scripture and theologians at all, but ultimately panglossians and secularists do meet on common ground.
Both have to examine the moral consequences of a rule before agreeing to live by that rule.
And that is the very essence of being a morally responsible actor.