In this paper I distinguish two ways of using the expression ‘epistemological naturalism’. In one sense, naturalism amounts to a denial that epistemology should be understood as a kind of first philosophy providing the foundations for science from outside. In a second sense, naturalism holds that human knowledge is a natural phenomenon and that epistemology should be seen as a chapter of natural science. Moreover, naturalism in this second sense usually incorporates some additional specifications that build up a very restrictive (...) concept of science. Two different projects for naturalizing epistemology lie behind these two meanings of ‘naturalism’, and the two projects, although sometimes seen as complementary or even equivalent, are not necessarily so. After drawing this distinction, I set out the difficulties faced by those naturalistic stances that do not discriminate sharply enough or do not establish the appropriate hierarchical relationship between both projects. Finally, I argue for a conception of epistemology which is best described as a radical antilfoundntionnlism. This conception sticks to the requirements that follow from naturalism when understood in the first sense above, and takes the cluster of theses that give birth to the second as subsidiary and revisable. (shrink)