(Thanks to neuro-philosopher David Chalmers for this cartoon...)
I'm reading University of Washington philosopher Laurence BonJour's "Against Materialism," one of the essays in The Waning of Materialism (Koons & Bealer, eds). One way some philosophers argue for materialism is by appealing the the general idea of "naturalism." BonJour finds such appeal unsuccessful.
First, "naturalism," while paid allegiance to, is hard to pin down in a precise way. "Many recent philosophers seem so eager to commit themelves to naturalism - to fly the naturalist flag, as it were - while showing little agreement as to what exactly such a commitment involves." (7) So naturalism, like materialism, seems to be an "intellectual bandwagon."
Second, naturalism "seems to just amount to materialism, which would make an argument from naturalism to materialism entirely question-begging." (Ib.)
Third, "one version of naturalism is the idea that metaphysical issues - or philosophical issues generally - should be dealt with through the use of the methods of natural science." (Ib.) But there is no good reason to suppose that the methods of science "exhaust the methods of reasonable inquiry."
Fourth, "there is no plausible way in which that claim itself can be arrived at using those methods." (Ib.) That is, using the methods of natural science cannot led one to the discovery that the methods of natural science exhaust the methods of reasonable inquiry.
Fifth, there is no reason to suppose that "applying the methods of natural science to the question of whether materialism is true, assuming that one could figure out some reasonably clear way to do that, would lead to the conclusion that materialism is correct." (Ib.)
It is true that many (but not all) natural scientists assume the truth of materialism. "But the question is whether they have any good reason for such an assumption - a reason that would itself have to transcend their strictly scientific claims and competence." (Ib.)
BonJour concludes that one cannot, therefore, reasonably use naturalism as a reason in favor of the truth of materialism. BonJour reasons that both materialism and naturalism function like "religious convictions." (Ib., 4)
(In the philosophy of mind "materialism" holds "that mental states are entirely either material or physical in nature, and correlatively that a complete account of the world, one that leaves nothing out, can be given in entirely materialist terms." (Ib., 3)
