Cuneo's 6 Arguments against realism: I

As far as I can tell, the heart of Cuneo's argument...well, that's not quite right. Let's try that again. As far as I can tell, Cuneo's argument has two hearts. One of the hearts is that anti-realism in epistemology is untenable. The second heart is that the arguments against realism in ethics apply just as well to realism in epistemology. He considers 6 arguments against moral realism, and shows how they extend into epistemology. I'll now write 6 posts, one going through each argument and trying to see how well it holds up. And, cuz I'm an undergrad and need practice with this sort of thing, I'll also recap the argument for antirealism Cuneo's dealing with. (I'm not sure I've got much interesting to say on all of them, including the first one below).

The first argument he considers is Blackburn's argument from supervenience. In short, Blackburn's argument is another way of trying to be precise about what's weird about ethical realism. It's generally believed that non-ethical propositions can't entail ethical ones, on the conceptual level. That is, is doesn't imply ought. Now that there is lack of entailment of ethical propositions from the plain old natural ones, does this mean that ethics is an independent realm of mysterious stuff that has nothing to do with the natural world? No, of course not. If two situations are identical naturally, then they are identical morally. And the only way for there to be a moral difference between two situations is if there is also some natural difference which underlies the moral difference. Let's call this relationship between ethics and the natural features of the world a supervenience relation. So ethics supervenes on the natural. Further, this supervenience relation seems to be a conceptual, analytic one: if somebody thought that you could get an ethical difference without some corresponding natural difference they would be simply misunderstanding what we mean by the ethical. (I guess that's true).

Blackburn argues that this supervenience relationship is odd. Note, for example, that it's quite unlike chemistry supervening on physics. Physics propositions can entail chemical ones, and this is what makes the supervenience relationship more easy to swallow. In a certain sense, chemistry propositions just are propositions about particles and atoms. That is, chemistry can be reduced to physics. But what we're claiming in ethics is that there is a supervenience relationship even though ethics cannot be reduced to the natural (unless you're a naturalist about ethics in which case they can be reduced!). This relationship seems mysterious. And if you want to cache out this mysterious relationship in a more precise way, we can talk about mixed worlds: since there's a supervenience relation, it's a necessary fact that in a universe, if the natural facts underly some ethical property for some object (they're hitting a baby makes them evil) then whenever any object has those natural properties in this universe they have that ethical property (ANYONE who hits a baby is evil). In addition, since there is lack of entailment on the conceptual level of ethical claims from natural ones, it's possible that in some alternate universe that set of natural properties won't underly an ethical property (in some universe hitting a baby doesn't make you evil). But how can we explain the fact that it's forbidden, by the supervenience relation, for there to be some universe where sometimes hitting a baby makes you evil, but sometimes it doesn't? Blackburn wants an explanation of this, and doesn't think it's possible for the realist to give a good one.

Now, what's doing the work in this argument? (Incidentally, "doing the work" is one of my least favorite philosophy phrases, though I have trouble dispensing with it). That is, in merit of what aspects of the nature of ethics does this argument work? What feature of ethics gets ethics into trouble? There's nothing too strange about a supervenience relation, but what is strange is the supervenience relation with the lack of entailment. So what is responsible for the lack of entailment? In short, it's the normative character of ethics; you can't get "ought" from "is."

So I don't have much to quibble with when Cuneo suggests that epistemology has the same problem. As long as epistemology is normative, then it too will have lack of entailment. And so it will suffer from the same problems that ethics does.

Of course, the problem for realism isn't just that something weird needs to be explained, but rather that no good explanation seems forthcoming for the realist. Is there any reason to suppose that there will be a difference for epistemic realism? The epistemic projectivist would still have available the answer that expressing an epistemic attitude is just expressing an attitude in response to natural features, and so I'm not sure I have much to add here. It's the bigness of the natural realm that makes it so hard to conceptually doubt the supervenience relation in ethics, and I think that as long as epistemology isn't natural then you have the same problem. I'm moving on, though I reserve the right to come back and update the post if I think of something better to say.

UPDATE: Well, I might as well add some stuff later about attempts to argue against the supervenience relation in epistemology by Lehrer (Cuneo writes "But if Lehrer is right, then it will also be true that moral facts do not supervene on non-moral facts"). Note also that we have to be careful here about whether we're talking about supervenience on non-moral/epistemic or on the non-normative/natural facts. There can be differences there. Also, Blackburn argues that the mental/physical and other supervenience relations don't supervene conceptually, and it's worth trying to explain more carefully why the epistemic will be conceptually supervening while the mental doesn't. I'll do that later.