As if
To say that people act “as if” moral realism is true is to take some set of behavior or practices we have established people engage in, then offer a theoretical account of why people engage in that behavior that explains what’s going on. In other words, we take some observations or data to be explained and present something like “an implicit commitment to moral realism” as the explanation.
Yet what realists typically offer as the data, or explananda, just is a claim about what the explanans consists in. They will say, for instance, that people deliberate about what the stance-independently correct course of action is, or they argue with the goal of convincing others of what the stance-independent truth is.
These are instances of conflating what’s to be explained with the explanation. What they offer as explanations of why people act “as if” moral realism is true are not the direct observations we have of people’s actions, but theoretical accounts of their the behavior.
People deliberate or reason about what they ought (morally or otherwise) to do. They argue with one another about moral issues. And so on. These are the actual observations. That ordinary people’s goal in these cases is to deliberate about what the stance-independent moral truths are, or to make propositional claims about what’s stance-independently true aren’t the observations, they are the realist’s hypothesized explanation of observations. The realist is mixing up what we observe with what they think explains what we observe. Alternatively, they just mistakenly take their realist presuppositions to be the observations. This would mean they’re presenting as observations or data their own theory-laden preconceptions. Nobody is obliged to grant such presumptions.
The data itself is what’s not (typically) in dispute. As I said, I don’t disagree that people engage in moral deliberation and moral disagreement. What I do not grant is that doing so in either case straightforwardly entails that they’re acting “like moral realists,” because there are antirealist explanations for what’s going on in these cases (deliberation, arguments, etc.). What a realist would have to do is show that their preferred account is the correct one, but doing so is an empirical question about human psychology. Such questions cannot be resolved by armchair theory. They can only be resolved with actual research.
Moral realists almost never present any empirical data to show that the psychological processes they propose as explanations for the behavior are, in fact, the correct explanations for the behavior. They just presume that they are. I think what might be going on here is a type of naïve psychological inference. The realist takes some behavior, like disagreement, supposes (on armchair grounds) that the best or only explanation for disagreements (or the nature of these disagreements) is realism, and then concludes that it’s just part of what we observe that people act “as if” moral realism is true. The antirealist’s burden, from their perspective, is to show how antirealism is true even though people act “as if” moral realism is true.
And many moral antirealists may simply go along with this and grant it. They shouldn’t. I don’t grant that people act “as if” moral realism is true.
Antirealists need to stop granting realist assumptions. And realists should stop playing armchair psychologist. It’s astonishing how transparent, shallow, and naïve their psychological theorizing is, and it’s frustrating that for decades there’s been almost no pushback from anyone, including academic antirealists.
There is no good reason to think it’s some sort of established fact that ordinary people act “as if” moral realism is true. Deliberating about what to do is consistent with moral antirealism. Caring about things is consistent with moral antirealism. Judging other people and cultures is consistent with moral antirealism. Arguing with others about what’s morally right or wrong is consistent with moral antirealism. I suspect every aspect of ordinary human behavior is consistent with antirealism. This doesn’t mean I think people are moral antirealists. What it does mean is that ordinary behavior underdetermines whether people are implicitly committed to moral realism or antirealism. The only way to know whether people are moral realists or antirealists is to conduct studies. It isn’t something you can settle simply by thinking about it.