There are many forms of naturalized epistemology and it is hard to say exactly what it is. The various forms have different views about the relations between natural science and traditional epistemology. In its most radical forms, naturalized epistemology holds that traditional epistemology should be abandoned or at least replaced by some empirical science, such as psychology. Other less radical forms of naturalized epistemology don't call for the abandonment of traditional epistemology but hold that the empirical sciences, especially psychology, can solve or help to resolve many of the problems confronting traditional epistemology. Others claim that there is “a continuity” between empirical science and epistemology. In general, proponents of naturalized epistemology stress the importance of the natural sciences for epistemological inquiry. In this chapter, we'll explore some arguments and claims made by the proponents of naturalized epistemology.

Quine and the replacement thesis

In his essay “Epistemology Naturalized” W. V. Quine offers one of the earliest defenses of naturalized epistemology. He argues that the traditional Cartesian epistemological project of deducing truths about the external world from infallible knowledge of our own mental states is a failure. Attempts to justify or to provide a rational reconstruction of our beliefs in that way are doomed. If knowledge did require such a justification, the result would be skepticism. (We discussed the difficulties with classical foundationalism in chapter 3.) Confronted with the failure of the traditional Cartesian epistemological project, Quine seems to recommend that we abandon epistemology in favor of psychology: