Because atheism doesn’t have a pope, ecclesiastical hierarchy, Bible, or creed, many people struggle to make sense of ‘atheist morality,’ and so you will find all sorts of people saying ‘X is consistent with atheism’ where X is some very bad thing (like eating babies).
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These people fail to understand the difference between consistency and entailment. With one exception, you can also say, “Not X or anti-X is consistent with atheism.” You almost never hear about that, however, because it doesn’t fit the dominant apologetics message.
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The one exception is that atheism is incompatible with any moral duties tied directly to God, such as worshipping God on the Sabbath. Other than that, atheism by itself says virtually nothing about morality.
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You can refer to the ethical beliefs of subsets of atheists: nihilists, secular humanists, Aristotelians, consequentialists, Objectivists, Buddhists, etc. (All of these are consistent with atheism.) But then you’re talking about something else, *not* atheism. 4/

This is why there is no such thing as THE (singular) atheist morality. There are many, in the sense that there are many ethical systems compatible with atheism.
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Because the idea of morality handed down from authority figures is so ingrained in the religious way of thinking (think God, Moses, Jesus, priests, etc.), theists seem to automatically assume that atheistic morality works the same way. ...
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So, even without an intent to quote mine atheists, they will seek out someone who they think probably speaks on behalf of most atheists on moral issues, such as Dawkins, Singer, or even Paul Kurtz. Again, this can be done with the most charitable intent.
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They forget that there is no atheist who speaks "ex cathedra" on behalf of atheism and sets 'atheist ethical doctrine." That's not how it works.
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The more fundamental issue is this. Because most theists are not “mere theists,” but Abrahamic theists, they naturally link their theism with specific moral values and duties, even if they are not a DCT-ist.
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They are so used to the idea that their theology determines their metaethics, that they assume an atheist’s ‘atheology’ must equally determine the atheist’s metaethics. But this doesn’t follow at all. Atheism merely entails the falsity of theistic metaethics (DCT, DMT, DWT)
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One has to go beyond atheism in order to determine which metaethical theory (nihilism, error theory, objectivism, etc.) is true. In other words, atheism underdetermines metaethics. This is why you can find atheists supporting every metaethical theory except theistic ones.
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This is also why moral arguments based on appeals to (hostile) authority, such as WLC’s moral argument which references Nietzsche, Mackie, and Russ, are utter rubbish.
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