Laurence Bonjour on Presumptive Naturalism
"Against Materialism" in The Waning of Materialism, eds. Robert C. Koons and George Bealer (Oxford University Press: 2010), p. 7.
A second sort of defense in favor of materialism appeals to the general idea of naturalism. Here again we have a view, like materialism itself, to which many, many philosophers pay allegiance while offering little by way of clear argument or defense, but here the view itself is much harder to pin down in a precise way. Indeed, even more striking than the absence of any very clear arguments is the fact that many recent philosophers seem so eager to commit themselves to naturalism — to fly the naturalist flag, as it were — while showing little agreement as to what exactly such a commitment involves. Thus naturalism seems to be even more obviously an intellectual bandwagon than materialism. (In addition, naturalism, for some of those who use the term, seems to just amount to materialism, which would make an argument from naturalism to materialism entirely question-begging.) ¶ Is there any genuine support for a materialist presumption to be found in the vicinity of naturalism? 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. If this is accepted, and if it is true that following the methods of natural science leads plausibly to an endorsement of materialism, then at least some presumption in favor of materialism might follow. But both of the needed suppositions are in fact extremely dubious, to say the least. There is simply no good reason to think that the methods of natural science exhaust the methods of reasonable inquiry — indeed, as has often been pointed out, there is no plausible way in which that claim itself can be arrived at using those methods.