Robert Wright is an atheist who argues that there is a moral law that somehow pervades the universe and which obligates us to do "right." P.Z. Myers is an atheist who sees things, at least this thing, much differently. Here's Myers:
Nope, says I. First, there is no moral law: the universe is a nasty, heartless place where most things wouldn't mind killing you if you let them. No one is compelled to be nice; you or anyone could go on a murder spree, and all that is stopping you is your self-interest (it is very destructive to your personal bliss to knock down your social support system) and the self-interest of others, who would try to stop you. There is nothing 'out there' that imposes morality on you, other than local, temporary conditions, a lot of social enculturation, and probably a bit of genetic hardwiring that you've inherited from ancestors who lived under similar conditions.
Other than changing the word "compelled" to "obligated" I agree with what Myers writes. Given his atheism he's absolutely correct to conclude that there is no moral law. There's no right or wrong, there's no moral obligation, there are just things that people do. An atheist, as Myers implies, has absolutely no grounds for believing in moral obligation or for making moral judgments.
Wright thinks otherwise:
[E]volutionary psychologists have developed a plausible account of the moral sense. They say it is in large part natural selection's way of equipping people to play non-zero-sum games - games that can be win-win if the players cooperate or lose-lose if they don't.
So, for example, feelings of guilt over betraying a friend are with us because during evolution sustaining friendships brought benefits through the non-zero-sum logic of one hand washing the other ("reciprocal altruism"). Friendless people tend not to thrive.
Be this as it may, it does nothing to explain why we're doing something wrong if we choose not to cooperate with others. Even if evolution has given us a moral sense, so what? That's hardly a reason why we should adhere to it. Evolution has given us wisdom teeth, too, but that doesn't mean that we need them.
Wright continues:
Well, a moral sense seems to emerge when you take a smart, articulate species and throw in reciprocal altruism. And evolution has proved creative enough to harness the logic of reciprocal altruism again and again.
Vampire bats share blood with one another, and dolphins swap favors, and so do monkeys. Is it all that unlikely that, even if humans had been wiped out a few million years ago, eventually a species with reciprocal altruism would reach an intellectual and linguistic level at which reciprocal altruism fostered moral intuitions and moral discourse?
This is all pretty interesting, but, even so, it's not at all clear to me that people are naturally altruistic. They seem much more obviously to be naturally egoistic. If we are what we are through evolution then evolution has shaped us to be self-centered and selfish.
But even if we grant Wright's argument that we've evolved to be altruistic how is this an argument for moral obligation? If people don't cooperate with others all that we can conclude is that they don't carry the genes for it. We can't conclude that they're doing anything wrong. Nor can we say that because blind, impersonal forces have caused us to tend toward mutual cooperation that therefore we're obligated to cooperate with others. That's as ridiculous as saying that because nature has given us facial hair we're obligated not to shave it off.
Evolution (maybe) can explain why humans behave the way they do, but it cannot "demand" that we ought or ought not to behave that way. It cannot provide a ground for saying that some choices are right and others wrong. Nor can it provide a ground for saying that people are morally obligated to do what helps others. Only God can impose moral obligation, and if there is no God then P.Z. Myers is right.
RLC
