In yesterday’s post, I attempted to defend moral psychology against criticism from philosopher Massimo Pigliucci. The crux of his criticism is that moral psychologists are using their scientific research to make normative moral statements, thus violating David Hume’s is-ought gap. As a consequence, they are encroaching on the field of moral philosophy. By way of analogy, Pigliucci compares the study of morality to the study of mathematics and natural science, implying that normative statements are theories of a moral realm, and that moral philosophers – unlike moral psychologists – study it directly.
My counter-argument is that, while I think Pigliucci is correct in pointing out that moral psychologists do on occasion violate the is-ought gap, this is simply due to imprecise language, not to overextension of their field. The point is that moral psychology challenges the notion that there is a moral realm, instead suggesting that normativity is a rationalisation of personal moral intuitions, disguised as a moral realm.
Although it seems to me the evidence for this is very strong, I think it’s useful to address the problem from a different angle and instead ask: does normativity add anything to moral discourse? Or framed slightly differently: do moral philosophers really contribute to moral understanding in the way Pigliucci suggests, or are they just engaging in moral psychology themselves, albeit with less methodological soundness?
I suggest the answer is the latter. The reason for this is that Hume’s is-ought problem works both ways. Pigliucci points out that one cannot logically derive an ought from an is, but the reverse is also true. This raises the interesting observation that – if it is true that moral philosophers operate through normative theories – their theories can have no logical bearing on the real world.
This is probably why theism struggled to separate God’s commands from His punishments. The claim alone that one ought to do something is powerless, but when it is replaced by real consequences (if you do X, then Y will happen to you) it becomes significant. There’s no reason for this to be different for nontheistic moral philosophies. And so, attempts to deduce behaviour from normative theories are doomed to fail – they can never be logically valid.
Moral psychology gets around this problem by avoiding normativity altogether. What's emerging instead is a model of moral language as expression of moral intuitions based on common evolved modules.
The long-term effect of this, it seems to me, is an elimination of normative morality. If people stop believing in a moral realm, there is nothing left for normative morality to do. Instead, people can simply treat moral discourse as the communication and negotiation of individual moral intuitions and individual values in general, combined with other information. If we assume this is already what’s happening, it’s simply a question of acknowledging it and making the process more effective.
In hindsight, one can seemingly conclude that moral philosophers have been expressing their moral intuitions when they’ve posited normative moral theories, just like other people do, as we now know. But in studying this process in themselves, that makes them proto-psychologists. But now that moral psychology has been established, is there still a role for moral philosophers?