International Philosophical Quarterly

Volume 51, Issue 1, March 2011

Realism, Nominalism, and Biological Naturalism

Biological naturalism claims that all psychological phenomena can be causally, though not ontologically, reduced to neurological processes, where causal reduction is usually understood in terms of supervenience. After presenting John Searle’s version of biological naturalism in some detail, I argue that the particular supervenience relation on which this account depends is dubious. Specifically, the fact that either realism or nominalism is the case implies that there is one fact about belief that does not supervene on neurophysiological processes. Biological naturalism is thereby defeated because it cannot account for belief. I also address three likely objections to this argument.