In a couple of places (some on other blogs), I've used "realism" as a term of abuse, as a counterpart to my equally abusive references to "relativism." This can be a confusing way of talking, so in this post I try to clear that up a bit. There aren't any real arguments here, just a more detailed, even plodding, statement of (the form of) my general attitude.
The first thing to understand is that when I say "realism" I mean the particular class of views also known (somewhat redundantly) as "metaphysical" realism, which does not mean "realism about metaphysical entities" (as opposed to, say, "empirical" ones), but a particular attitude toward objectivity in general (whatever sorts of entity are seen as objective). For me, in other words, the question of realism and relativism boils down to the question of what objectivity is (that is: how the concept of objectivity works) and how one can go wrong by misconstruing it. Once we understand that, it doesn't really matter to me whether we say that we have finally refuted "relativism" or that we have finally given it a proper defense. On the other hand, I do have my own preferred way of talking, which is a reasonably common one (see Putnam, R. Bernstein, etc.), according to which what we are to do is to find a way between the Scylla of "realism" (or "objectivism") and the Charybdis of "relativism" (or "nihilism," etc.). (For comparison see Joseph Margolis, who wants to defend "a version of relativism which is compatible with realism." I'd rather not talk like that.) Also like Putnam, I use "relativity" (as in "cultural relativity") to refer to the uncontroversially empirical fact of cultural difference, the significance of which realists explain one way (we see things the Way They Really Are, while their view is distorted by their alien conceptual scheme) and relativists another (everyone, or every culture, has their own way of seeing the world, none more "real" or "true" than another).
For me, and I'm sure for Rabbit also, if we start with the characterization I just gave, the relativist at the very least takes an early lead: he has taken the correct attitude, as the realist has not, w/r/t the pernicious idea that there is a single correct ("objective") view, or conceptual scheme, or Way Things Are. I agree with many others (for Margolis's version see Pragmatism Without Foundations) that one does not fall into a radical nihilism (nothing is true!) or relativism (everything is equally correct!) simply by rejecting realism so construed. Where we all differ concerns what we should, or have to, say in order to arrive at a stable position between realism and the radically silly positions we all reject (not that realism isn't silly in its own way, mind).
So let me say more about the basic position I am taking all non-realists to accept. ("Non-realism," in my usage, is the bare negation of "realism." "Anti-realism," on the other hand, is a proper subset of "non-realism": it is the genus of which nihilism, relativism, instrumentalism, and (constructivist or empiricist) idealism – views I reject as, well, insufficiently realistic – are species. We'll get to my positive views – the options for non-anti-realist non-realism – later. Got that?)
Here it goes. Realists are confused. The way they talk, you'd think people's statements were just free-standing propositions (i.e., inexplicably meaningful objects) describing How Things Are Independently, to be judged (as true or false) by peeling their propositional content out of the context of their utterance and holding it up to the one objective world to see if they match (and if they do, giving them the Stamp of Approval ("True")). But they're not. They are (or are the result of) particular people's actions and judgments, which happen in a particular (e.g. cultural) context, with a particular (e.g. cultural) meaning, and are therefore to be judged with respect to the appropriate standards for that action, whatever they may be (something which is itself to be judged by the participants, not by transcendent "objective" criteria, whatever that means). So what if that "condemns" us to failing to "transcend our subjectivity" and reach some sort of perspective-independent "reality." There's no such thing, and even if there were, it's not clear that we should have any interest in it. Our interest is in what is in front of us – the actions and judgments primarily, and the proposition derivatively – and those are precisely not "perspective-independent."
Again, though, this is just what's wrong with realism. (My account so far is indeed one-sided and thus, I recognize, sounds a lot like relativism. Keep reading.) Realism falls into incoherence when it tries to abstract the content of our utterances (beliefs, etc.) away from the only context in which it makes sense to see them as contentful – and it must do this, given that it is the essentially "subjective" (e.g. "interested," "perspectival," etc.) nature of our beliefs as constituted in that context that makes them unacceptable, for realists, as candidates for knowledge of the real. Instead, realists argue, we must rigorously strip away the subjective distortion of our individual, engaged perspectives and see the world as if "from nowhere" (see B. Stroud, T. Nagel, and B. Williams for characteristically Cartesian statements of this ideal -- although they differ in their levels of confidence concerning how successful this "project of pure inquiry" can be). This, I claim without argument, makes no sense. It's the idea that Kant, for example, mocks as that of the seagull who, tired of fighting wind resistance, dreams of someday flying in a pure vacuum (oops).
But a thoroughgoing relativism (instrumentalism, communitarianism, etc.) suffers from a corresponding difficulty. If the validity of our discursive states and utterances depends solely on internal or social/contextual standards rather than on their relation to the world, it's hard to see what makes them beliefs or utterances about the world, that is, contentful or meaningful beliefs and utterances, at all, instead of a (perhaps culturally "meaningful" but) essentially nondiscursive or non-intentional state or interaction. After all, it is essential to their nature qua semantic phenomena that beliefs and utterances can be false, and they're false when what they say doesn't match up with how things are (i.e. independently of how we believe them to be) – that's how it is that we can see them as saying anything in the first place; or, switching it around, what they say (their meaning) is how things are when they're true (and not when they're false). To accept this is just to know how to use semantic/interpretive language ("mean", "believe", "true", "false") at all, and to do that is just to participate in the practice of (as Brandom and McDowell like to say, following Sellars) "giving and asking for reasons" and to accept rationality as a norm. Contra relativists, we go wrong (in the realist direction) not simply by doing this at all but instead by reading into this perfectly innocent ("everyday," "ordinary") way of talking some tendentious metaphysics (and/or epistemology, and/or semantics) according to which rationality, or truth, or objectivity, or whatever, swings free ("dualistically," as I will say) of the practice that gives those concepts meaning. (Again, I see Kant as aiming at the same thing; but one way in which he goes wrong is by misconstruing the nature of "possible experience" as the only coherent referent of our concepts. The idea of "practice" (or "use," when that is construed properly; if not, it dumps us back into communitarianism), works better in this role.) But we go equally wrong, in the opposite direction, if we recoil (a useful term I picked up from McDowell; see e.g. ch. 1 of Mind and World) from this sort of realist hypostatization or idealization into denying the characteristic nature of semantic or discursive phenomena entirely – as if the very idea of being subject to norms of rationality, or of a universally accepted falsehood, or of seeing the world as in some way "objective" ("independent," etc.) were necessarily objectionable in the way realism is. This is why attacks on "metaphysical realism" often go under the name "[some sort of] realism" themselves, like Putnam's "pragmatic realism," or even some sorts of "scientific" realism (perhaps overly charitably construed). Again, to preserve the symmetry here, I abjure the name "realism"; but the point is that I need not object to everything that goes under it, as sometimes it does indeed refer only to the everyday ("commonsense") ideas that realists fail to distinguish from their tendentious theoretical distortions of same.
It is of course risky to commit oneself to a way of talking in advance of discussing the particular cases this way of talking is supposed to allow us to illuminate. And of course that's all I've done here: given the form of my account, i.e., "[X = the content of my account] shows the difference between a perfectly natural distinction and a philosophical dualism, and here' s what to do about it," etc. But there it is; we'll get to particular cases soon enough.