I've been a little bit perturbed by the implications of my post on atheism and relativism. If atheistic systems of morality are all internally inconsistent then it would seem that atheism as a whole is an untenable position. However, theistic systems really aren't any better, since they tend to be counter-factual. Where does that leave us since, by definition, there isn't anything left once you've gotten rid of theistic and atheistic systems?
I got into discussion with an anonymous poster on the subject, at which point I said
A right/norm must come from somewhere be it natural or supernatural (I'll allow that this might be a false dichotomy, though I'm unsure what other sources may exist). Most atheists explicitly reject the normativity of both of these sources, leaving themselves without a rock to stand on.
Later I got to thinking that I might be wrong in that regard; "natural/supernatural" could be a false dichotomy, in which case there's the potential to salvage atheistic systems of morality.
Is there a source of normative behavior that is neither "natural" nor "supernatural"? Strangely enough, when I was thinking that question over I realized that the definitions of "supernatural" and "natural" were somewhat tenuous. The term "supernatural" is generally defined in opposition to "natural", e.g. the supernatural is that which is not natural. But if you go and look up the definition of "natural" you find that it has a myriad of connotations. Its not clear to me which definition is being referred to in the "natural/supernatural" dichotomy and whether that definition makes an appropriate basis for comparison.
Let me ask a rhetorical question: Is representative democracy natural? I usually ask this question in the context of debates on homosexuality to demonstrate that some speaker, while asserting that homosexuality is unnatural, simultaneously values other concepts that are equally unnatural. But I believe that its sheds light on the immediate question as well. In one sense representative democracy is "natural" in that it can be explained via appeal to naturalistic phenomena. But in another sense its not natural, since it doesn't occur spontaneously without the intervention of sentient beings.
So now we have another dichotomy, "natural/unnatural". Here's where we have to stop and consider whether this really represents a true dichotomy or if its just an artifact of language. What I'm setting up in place of the "natural/supernatural" dichotomy is a "natural/unnatural/supernatural" trichotomy. Does this additional category actually refer to anything?
Google the phrase "preserving nature" and you turn up a bunch of hits about protecting wilderness and such and the like. From what do these pages seek to protect it? Not from more nature; "protecting nature from itself" doesn't really make sense as a concept. Neither is there the suggestion that wilderness areas are in danger of being overrun by poltergeists. Rather, all of these results returned from the Google search imply that nature needs to be protected from the actions of mankind. This, in turn, makes a strong case that humanity is commonly perceived as having transcended the bounds of nature.
Its also possible to make the case that any discussion of morality presupposes this distinction. Systems of morality are, after all, exclusively concerned with human behavior. There are few who seriously suggest that plants and animals are capable of behaving immorally; no one censures the wolf when it kills a deer, or suggests that maybe it should think about vegetarianism as an alternative. Rather, the killing of prey by predator is seen as a natural phenomena beyond the bounds of morality. However, human behavior doesn't get a free pass, indicating that it is unnatural in the "representative democracy" sense of the word.
So, the category of "unnatural" is real, and not just rhetorical slight of hand, allowing us to substitute the trichotomy of "natural/unnatural/supernatural" is place of the "natural/unnatural" dichotomy. It doesn't necessarily follow that there is a legitimate source of rights to be found therein, but at least we're no longer axioming outselves out of existence.
Let's follow that thought. If there is a legitimate source of rights within atheistic moral frameworks it must stem from the domain of "unnatural" things. In order to understand where an authority might be found its first necessary to understand what things, real and abstract, are part of this domain. From the discussion above we know that the behavior of animals is part of the "natural" domain but the behavior of humans belongs to the "unnatural" domain. Why?
This is where things get a little get a little tricky. The immediate answer that comes to mind is "self awareness", but thats obviously not the whole answer. Apes, elephants, and dolphins also show signs of self-awareness, but there are few who suggest that such findings (if true) are cause to subject these creatures to moral survey and censure. What separates humans from these animals?
The usual suspects (language, culture, tool use, etc.) are increasingly unreliable; recent research has shown that the difference between ourselves and other animals in this area are a matter of degree rather than kind. Perhaps these animals lack the capacity to act morally? In order to act morally one must be able to recognize that a situation requires a moral response. And yet, anecdotal evidence suggests that animals have the capacity for empathy i.e. they have the capacity to recognize another animal's distress1. But moral culpability, in addition to requiring the capability to recognize a problem, also requires the ability to effectively address the problem. Other animals lack the ability to address moral problems in a substantive way, even if they have the ability to recognize them. What separates humans from animals, and what ultimately disengages us from the "natural" domain, is the degree to which we are able to act to shape our environment.
The "unnatural" domain, then, is where we place those entities with the ability to shape their surroundings to a high degree. I'm uncomfortable with this definition, relying as it does not on a "bright line" criteria but rather on a judgement of capability, but that's not entirely relevant. Human beings clearly meet the standard, and as such are included within the domain. Any other sentient entity of sufficient capability also belongs in this domain, in the off chance that any aliens are reading this blog.
After a long slog we've come to the point where we can say that an atheistic basis for human morality must be derived from humanity in some regard. Here there is enough room to definine moral axioms, though the formulation of such axioms is restricted in certain respects. Because they are derived from the "unnatural" domain they will generally have to place limitations on their own applicability e.g. "suffering should be minimized if feasible" rather than "suffering should be minimized". Or such axioms must explicitly reference to whom they apply, e.g. "entities possessed of empathy and an ability to substantially shape their environments should seek to minimize suffering wherever possible".
I especially like that last one, cold and clinical though it may seem. "possessed of empathy", "the ability to substantially shape their environments" and "minimize suffering" aren't terribly abstract; its fairly easy to argue that they correspond to conditions in objective reality. Contrast this with axioms which reference concepts like "justice"; justice is a human construct, so using it as a basis for human morality is circular reasoning.
In summary, it seems that I was mistaken regarding the formal consistency of atheistic theories of morality. The formulation of such theories is possible, based on the introduction of the "unnatural" domain as separate from the "natural" and "supernatural" domains. It is possible to formulate normative axioms within the unnatural domain which, when properly constrained, are internally consistent. This places atheistic theories on the same logical footing as theistic theories.
1 See also this paper
by Paul Shapiro.