He’s contrasts them – kinda. So do I, but for different reasons. Here are the two bottom lines from Justin Clarke-Doane’s paper “The ethics–mathematics analogy” in Philosophy Compass 2019:
This argument is a kind of radicalization of Moore’s Open Question Argument. … The point … is that an agent may know that A is F, for any property, F, whether descriptive or ethical, while failing to endorse A. … if the argument works, it works for any normative properties, whether ethical, epistemic, prudential, or all-things-considered.
In general, if one is an ethical anti-realist on the basis of epistemological considerations, then one ought to be a mathematical anti-realist too. And, yet, ethical and mathematical realism do not stand or fall together. Ethical questions, insofar as they are practical, cannot fail to be objective in a way that mathematical questions can.
But what does he mean by “practical” near the end of the second passage? Clarke-Doane repeatedly refers to “whether to do” what the ethical (or epistemic or prudential) norm says to do. Apparently a “practical” question is one that settles whether to do X, for some particular X.
Before we evaluate whether “whether to do X” questions can “fail to be objective”, I should explain how certain mathematical questions can fail to be objective, on Clarke-Doane’s view. That is because mathematical pluralism is true of at least some mathematical domains. (I know little about philosophy of mathematics, but I must say I find mathematical pluralism highly plausible.)
Clarke-Doane: “Just as Euclidean and hyperbolic geometries are equally true, albeit true of different structures, the mathematical pluralist maintains that foundational theories, like (pure) set theories, are too. It is as though the most uncompromising mathematical relativism were true.” And: “At first approximation, mathematical pluralism says that any (first-order) consistent mathematical theory is true of the entities of which it is about.” On this basis Clarke-Doane concludes that mathematics, if pluralists are correct, is truth-bearing but not objective. I’ll take this as partially definitive of what “objective” means here. So I guess this means: if you get to pick which theory to use, it’s not “objective”.
How might one conceive or defend an ethical pluralism comparable to mathematical pluralism? Clarke-Doane asks us to consider an “ethics-like” system ethics*, which has slightly different norms and as a result tells us not to do some particular X that ethics tells us to do. Then we might wonder whether to do what ethics tells us to do in the situation, or what ethics* tells us to do. As for why ethical pluralism might be defensible, Clarke-Doane suggests that Cornell Realism implies it, as do moral functionalism and Scanlon’s metaethical views. I call my own view “Cornell Constructivism”, but that’s for another time.
Of Clarke-Doane’s two bottom lines, I agree with the first and a small part of the second. The first was that one can accept that A is F, for any normative property F, and yet not endorse it. But this undercuts Clarke-Doane’s claim in the second bottom line that ethics is “practical” in his sense. Of course it may be practical for some people – ethical people. Highly ethical people may see no daylight between concluding that an act is right, and endorsing it and going for it. On the other hand, extremely sociopathic people might see no attraction at all in the ethical. And turning to philosophical thought-experiments, it seems easy to conceive a demon who regards the ethical as a property to be avoided at any cost.
Clarke-Doane might reply that you either do X, or do not, and that is what makes it objective. But that you do X (or not) does not imply that you ever evaluated X at all. I’m really not sure what Clarke-Doane is getting at, and I worry that I’ve overlooked a better interpretation. But I can find no interpretation that truly logically connects from “ethics is practical” to “it cannot fail to be objective” and also makes both plausible.
I agree all too much that “ethical and mathematical realism do not stand or fall together” – too much to have nearly as much patience with the ethics-mathematics analogy as Clarke-Doane does. Ethics is bound up with experience in ways that make the analogy a non-starter. Ethics is about how we can flourish and get along. We who address ethical reasoning and justifications to each other. We who accept or reject these reasons and justifications, and propose alternatives. In order to determine whether our interlocutors can reasonably accept our proposals, we have to study and listen to them. In order to check whether we reasonably make the proposals, we have to study ourselves – and our common humanity will allow this to shed light on others.
Ethics isn’t a priori. It’s mired in empirical learning.
Justin Clarke-Doane has done philosophy an enormous favor by radicalizing – to the point of absurdity – Moore‘s Open Question Argument. Even Moore’s own “simple non-natural property” of goodness fails to pass Moore’s own test. We can agree that an act has Moorean Goodness and still wonder whether to do it. But if no normative property can conceivably pass the test, this shows that the test is not an appropriate test of normativity. There is no pure normativity – “pure” meaning utterly empty of descriptive content – to be had in this or any other universe.
We can endorse an action as prudent, or ethical. We can endorse an inference as logical. We can endorse a theory as epistemically virtuous. In none of these cases are we simply saying “yay, action/inference/theory!” In none of them are we purely expressing approval, or an intention to act/infer/theorize. There is additional information we are implying.
We can of course just endorse. Endorse without an “as” (as ethical, as logical, etc.). Endorsing, that is, without any value judgement. But that’s not normativity.
No ghost, no machine, only human 