Let's focus in on moral claims. My most doughty critic Jerry Coyne (really, I should pay him a retainer) says “while science can inform moral judgments, in the end statements about right or wrong (or, in Ruse's case, whether one should feel ashamed of an action) are opinions, based on subjective value judgments.” And he goes on to say “I think that's true.”

Let me say bluntly -- and it really is nothing personal because if it were I would be including a lot of my fellow philosophers including some of my teachers -- I think this is just plain wrong. I want to say that what Jerry Sandusky was reportedly doing to kids in the showers was morally wrong, and that this is not just an opinion or something “based on subjective value judgments.” The truth of its wrongness is as well taken as the truth of the heliocentric solar system. It's just not an empirical claim.

That's a good deal clearer than what he wrote in his original post. I am happy for the clarification, since it seems I misunderstood his intent in my reply to his first post. Alas, as we shall see, things get very murky again later in the essay. So let's consider his argument.

In my day-to-day life I am an unabashed moral absolutist. Some things are just right and others are just wrong, and if you disagree with my judgments than I will unleash upon you a barrage of stern looks and disapprobation. I simply regard it as obvious that people have certain obligations to one another, and I really have no desire to debate the matter.

But if you absolutely force me to defend my beliefs in terms of something simpler, it seems to me that I would have to give you some sort of standard by which I assess moral claims. I would have to say something like, “X is wrong because...” followed by some statement, probably related in some way to the consequences of X, that justifies my negative opinion of it. And at the end of the day I don't see how you can give an absolute justification of that standard. No matter what standard I provide, I don't see how I can reply to someone who steadfastly insists that I'm doing it wrong.

(As an aside, I don't see how it's much help to bring God into this. If God exists, then was can say that there is a standard of morality that is independent of what any individual person thinks. But then we just have two new questions to answer: How do we know what God thinks about moral questions? And why should we follow God anyway? Since I don't think theists have much to offer in the way of good answers to those questions, you'll pardon me for not granting them a privileged position in debates of this topic.)

Now maybe it doesn't matter that someone can challenge my premises forever. After all, science suffers from the same problem. In defending the heliocentric model of the universe I might point to its impressive predictive accuracy, but a hardened skeptic can retort that I shouldn't care about that. I can think of replies, but the fact is that any field of inquiry is ultimately based on assumptions that cannot be defended in terms of something simpler. So if the ability to challenge premises forever means there are no moral facts, then it also means there are no scientific facts.

Somehow, though, the sense in which one can endlessly challenge scientific assumptions just seems different from the sense in which one can endlessly challenge moral assumptions. People really do adhere to wildly different ideas about the basis for moral reasoning. A defender of divine command theory, for example, is taking a fundamentally different view from someone taking the approach defended by Louise Antony in this New York Times essay. By contrast, the assumptions underlying the validity of scientific reasoning really do seem to be near-universally accepted.

It is an interesting fact that on many, perhaps most, moral questions, the various different approaches to morality really do seem to converge on the same conclusion. Child rape is not morally ambiguous. I am not aware of any moral system defended by any significant number of people that takes the opposite view. So maybe such widespread agreement from so many different starting points is enough to justify the idea that there are moral facts after all. I'm genuinely uncertain about that.

What I am certain of is that for any practical purpose it is irrelevant whether you think “Child rape is wrong” is a cold hard fact, or merely an opinion that any sensible person should hold under penalty of being exiled from all polite company. In practical terms all that matters is what you can get people to agree to. And in the many situations where genuine moral disagreements arise, it is no help at all to insist that your view of the matter is simply a fact.

Okay, back to Ruse. How does he say we should think about morality?

A subjective value judgment is something on which decent, thoughtful people can differ. I think Grace Kelly was the most beautiful film star we saw in the philosophy of film course this last semester. Some of my students thought that Catherine Deneuve was. Who is right? Who is wrong? And what about the chap who voted for Marilyn Monroe? Decent, thoughtful people do not differ on Jerry Sandusky's alleged actions.

I agree that decent, thoughtful people do not differ on Sandusky's alleged actions, and I'd be willing to bet that Jerry Coyne, Ruse's foil for this little exercise, also agrees. But since judgments about who is being decent and thoughtful are themselves a tad subjective, I don't know if this observation entails that there are moral facts.

Ruse next quotes David Hume to the effect that you cannot derive from ought from is. Again, no disagreement from me. Empirical facts are certainly relevant to moral reasoning, but making the jump from is to ought requires bringing something extra, something nonempirical, to the table.

Which makes the conclusion of Ruse's essay a bit odd:

So how do you justify moral claims? Some philosophers and theologians think you can do it by reference to so-called non-natural properties or perhaps the will of God. Others, and this includes me, think that perhaps morality has no objective justification in this sense. (Although there is a subset that includes me who think that part of our psychology is to think that there is such an objective justification.)

I will leave the so-called moral realists to make their own cases. How does a non-realist like me proceed? One could be some kind of social contract theorist and think that a group of wise old people sat down one day and made up the rules of morality. This seems to me to be unsatisfactory both as history and philosophy. I go rather with the late John Rawls in his Theory of Justice, thinking that natural selection put morality into place. Those proto-humans who thought and behaved morally survived and reproduced at a better rate than those that did not. (There are all sorts of good biological reasons why cooperation can be a much better strategy than just fighting all of the time.)

So what does this make of morality? Sure, it is something that is part of our psychology. Frankly, who would ever doubt that? If you like, the controversial part is that it is only part of our psychology. I think that is the world into which David Hume pushed us. But because it may be the case that we can do what we like, it doesn't follow that we should do what we like. As evolved human beings, the rules of morality are as binding on us as if we were the children of God and He had made up the rules.

So that is why what Jerry Sandusky allegedly did was wrong - really and truly wrong. That is not a matter of opinion. It just isn't a scientific statement.

I can't follow this at all. Ruse just got through telling us that you cannot derive ought from is, but isn't he doing precisely that in these final paragraphs? It looks to me like he is pointing in some way to the facts of human psychology and to the vagaries of our natural history as the justifications for our moral beliefs. He seems to be saying (and I need to be careful here since I have already been burned once by his murky writing), that Sandusky's actions are really and truly wrong because natural selection has programmed us to believe they are wrong. Can someone explain to me what I'm missing? It sure looks like Ruse has contradicted himself here.

Moreover, natural selection has programmed a lot of things into us, and not all of them are admirable. We seem to have a penchant for xenophobia and tribalism, for example. They might well have been helpful survival strategies at one time, but today they seem distinctly harmful and frequently lead to immoral actions. We are capable of great altruism, but we also seem to have a natural tendency towards selfishness. Does Ruse's approach help us distinguish the aspects of our psychology that lead to good moral impulses from the ones that do not?

Also, while I'm willing to accept that a capacity for moral reasoning is a basic part of our psychology, no doubt bequeathed to us by natural selection, our specific concepts of what is right and what is wrong really do show quite a lot of variability. Concepts of right and wrong differ among contemporary cultures. They also evolve over time. For example, today nearly everyone regards it as obvious that slavery is wrong, but just a few centuries ago most people held the opposite view. Can Ruse help us make sense of this? Can Ruse apply his methods to resolve any current area of moral controversy? Do appeals to psychology and natural selection help us resolve questions about abortion or homosexuality, say?

Ruse's essay was meant to establish that there are moral facts that we come to know by non-empirical means. If anyone thinks he has been successful in that regard please tell me about it in the comments. To the extent that I understand what he is saying, and it is frustrating that he just doesn't seem to value clear writing these days, he has established neither that there are moral facts nor that he has some reliable, nonscientific means of determining what they are.