Mackie, moral nihilism vs. subjectivism and why the difference is no big deal 

 

There’s some dispute about whether Mackie, the author of the celebrated ‘queerness’ argument against objective moral properties thought that there were no moral facts, or that these facts were subjective in nature. The argument says (roughly) that if there were any objective moral properties these would have to combine the two following features. First off, they would have to be reason giving, in the sense that if the property of moral goodness applied to a person’s potential action this would give them reason to perform that action. But secondly, as objective properties of actions, they would apply or not apply to types of actions regardless of the motivations which any particular person in a position to perform that action might have. Thus objective moral properties would give rise to categorical imperatives; they would be features of the world which gave everyone (whatever their desires and values might be) reason to perform certain actions. We can see how actions can have objective properties (like maximizing utility or spreading HIV), and how they can subjective relations to agents (like being desired by the agent) which give rise to reasons for agents to act. But objective moral facts are different from these facts and queer in that they would have to give rise to reasons which applied categorically (i.e. to everyone, regardless of what their desires or values might be).

The controversy just mentioned concerns how Mackie meant this result. Did he intend to argue that if there were moral facts they would have to be objectively prescriptive, and nothing can be both objective and prescriptive so there can be no moral facts? Or is the point that moral facts must be subjective because if they were objective they would be objectively prescriptive and hence queer?

I want to suggest (without making any claims to serious Mackie scholarship) a third option. This is that nothing of philosophical importance hangs on the choice between the first nihilist and the second subjectivist version of the argument, and that Mackie may have, realizing this, expressed himself sometimes one way and sometimes the other out of courtesy.

Some people, like Kant, think that –as a matter of language– nothing could count as a moral fact unless it gives everyone reasons independent of their desires. Other people like Hume disagree in their linguistic intuitions and give ‘moral theories’ on which moral facts are motivating by way of an agent’s desires and values, e.g. their moral sentiments. If we are convinced by the argument from queerness that there could be no properties which were both suitably objective and motivating then we face a linguistic dilemma in how to report this discovery. If we have Kantian intuitions about what it would take for something to count as a moral fact we will say that we have discovered that there are no moral facts. If we have Humean linguistic intuitions we will say that we have discovered something striking about the nature of moral facts: that being prescriptive they cannot be objective. And if we have weak linguistic intuitions on this subject, or if we are simply more interested in metaphysics then the precise application of certain terms in natural language then we will phrase our view differently depending on our audience, saying to the Kantian that there are no moral facts and the Humean that moral facts can’t be objective.

The issue strikes me as exactly similar to the following case in natural science. Consider one of the early people to phrase the theory that atoms aren’t (as their name suggests) indivisible but rather are composed of protons, neutrons and electrons. Some people they encounter will feel that the essence of being an atom is to be indivisible, so that it is an analytic falsehood that atoms could be composed of anything else. Others will understand atoms more as ‘those things which are making the cloud trails’ and take the divisibility of atoms to be an empirical question. We can easily imagine this physicist expressing himself to these people sometimes by saying that ‘there are no atoms’ and other times that ‘atoms are composed of protons neutrons and electrons’. One can even imagine a debate after the scientist’s death about whether he was ‘an atom nihilist’ or ‘a divisiblist about atoms’ with each side citing quotations in their favor. Surely in such a case where the evidence is mixed it is better to suppose not that the theorist held one view and occasionally contradicted himself, but rather that he cared more about the metaphysical thesis than about the linguistic matter of essences, and expressed himself sometimes one way and sometimes another as courtesy and intelligibility to different audiences required.