Anti-realism about moral value is a thesis not about judgment, but about the moral or evaluative properties that are picked out in such judgment. The thesis is that these properties are not metaphysically real. Hare guesses that Foot’s sympathies were with the metaphysical realist. This is certainly true of Hursthouse, whose view is closest to McDowell’s account of moral realism. R. M. Hare (RMH) was, as Blackburn puts it, a “quietist” on the issue of moral properties, holding that no real issue can be built around this kind of objectivity of moral value. He was agnostic on whether there are “real” evaluative properties, but he was not explicitly anti-realist. So the interpreter of RMH who thinks the metaphysical question about the objective reality of these properties does make sense is in the same position as the interpreter of Foot who shares that view. We have to speculate about what our authors would have said if they had thought this was a good question.
Hare suggests Foot’s sympathies would have lain with metaphysical realism, but that RMH’s sympathies would not. RMH consistently held that the truth conditions of moral statements are given by the criteria adopted by the speaker. He would have probably claimed a question about real properties picked out by moral judgments was confused. He would have probably, if pressed, denied there are such real properties, which is why he’s so consistently misunderstood.
Hare’s own view on these matters is what he calls “prescriptive realism.” He agrees with RMH about motivation but disagrees with what RMH would have probably said about moral realism. Judgment internalism is a thesis about moral or evaluative judgment, and realism is about moral or evaluative properties, and there is no reason why we should not say that there are indeed these properties. But when we make judgments about them, we not only claim that they exist, but express an attitude of emotion, desire, or will. If we do this, we will be both expressivist and realist, in the sense that they are there whether the relevant attitudes are there in the person making the judgment or not.
Why should we want to be realist about the properties? Hare thinks our evaluative language suggests an ontological commitment. Any full causal explanation of the events of Hitler’s life, for example, requires reference to his moral depravity. Before embracing error theory, we would need to be shown there’s some persuasive metaphysical principle that rules out the reality of moral and evaluative properties. For a theist in particular it is going to be hard to find such a principle. The point of prescriptive realism, though, is that, even if we concede the reality of the moral and evaluative properties, we do not have to deny the insight of the expressivists about one of the central functions of moral and evaluative judgment, namely, the function of allowing us to coordinate our lives together by expressing in these judgments our commitment to live a certain way.
What’s important for present purposes is the implication of this disagreement for deductivism. Even if we allow, with the realists, that there are evaluative properties independent of our judgment about them, the case still has to be made by a deductivist that there is an implicative relation (independent of a decision of principle) between natural facts and moral goodness. Even if RMH were to agree on the realism, he could still disagree on the claim about implication.