This paper attempts to specify the conditions under which a psychological explanation can undermine or debunk a set of beliefs. The focus will be on moral and religious beliefs, where a growing debate has emerged about the epistemic implications of cognitive science. Recent proposals by Joshua Greene and Paul Bloom will be taken as paradigmatic attempts to undermine beliefs with psychology. I will argue that a belief p may be undermined whenever: (i) p is evidentially based on an intuition which (ii) can be explained by a psychological mechanism that is (iii) unreliable for the task of believing p; and (iv) any other evidence for belief p is based on rationalization. I will also consider and defend two equally valid arguments for establishing unreliability:the redundancy argument and the argument from irrelevant factors. With this more specific understanding of debunking arguments, it is possible to develop new replies to some objections to psychological debunking arguments from both ethics and philosophy of religion.
I think Leben’s thesis has force beyond moral and religious beliefs. For example, Leben’s criteria could be applied to philosophical intuitions in general once we have more data on philosophical intuitions (e.g. mindedness, personhood, consciousness, ontology of political entities, etc.). Since this kind of research seems to be relatively new, Leben is probably shrewd to single out more robust results. Still, I look forward to doing (and reading) work on philosophical intuition as the germane research continues.
UPDATE 2014: I have just discovered Derek Leben’s podcast “Axons and Axioms…dedicated to all things philosophy, psychology, and neuroscience.” For other podcasts and websites that might interest you, see my “Other Stuff” page.