ABSTRACT
The scientific explanation of religious belief is commonly taken to be a subversive enterprise. To explain religion as due to natural causes is to explain it away. If Boris’s belief in God is due (a) to a Russian Orthodox upbringing and (b) to a tendency to take the universe personally owing to an HADD or hypersensitive agency detection device, this seems to suggest not only that Boris’s belief is unfounded and irrational but perhaps that it is false. But this seems odd since at first sight the causes of a belief are irrelevant to its truth and even to its status as knowledge. Can a causal explanation— especially an evolutionary explanation—of why we believe something cast doubt on the things we believe? I shall argue that the answer is yes—under certain circumstances.
If the explanation shows either that X’s belief in the claims P is due to an unreliable mechanism or that X would have been likely to believe the claims P whatever their truth-value, then X’s beliefs do not amount to knowledge. ( Note that the second disjunct is stronger than the first. It is one thing to show that a belief-forming mechanism is unreliable since it tends to generate false beliefs. It is another thing to show for a particular set of propositions that they would probably have been believed whatever their truth-value.)
If the explanation shows that some claims P are widely believed because of an unreliable mechanism or that they would have been widely believed whatever their truth-value, and if the only reason to believe the claims P is either that they are widely believed or that they are individually difficult to doubt, then this suggests (given Ockham’s razor) that the claims P are false. Thus, an explanation can only suggest that a belief (or set of beliefs) is false if the belief-inducing mechanisms involved are truth-insensitive and there are no other decent arguments for the belief or beliefs in question.
A psycho-evolutionary account of our propensity to form religious beliefs cannot challenge the truth of a specific set of beliefs unless there are no other (decent) arguments for the truth of these beliefs. In particular there must not be a well-authenticated history of the beliefs in question which traces them back to the right kind of causes such as an act of divine intervention. Such a history would constitute an historical argument for the truth of those claims.
Since almost everyone agrees that we have a truth-insensitive tendency to acquire religious beliefs, the evolutionary explanation of this tendency does not add that much to the skeptical case against religion. For it is already generally agreed that we have such a tendency and also that it is highly unreliable. For most religious believers think that most religious beliefs are false.
