 Naturalism in epistemology, as elsewhere, has a long history. But it is only relatively recently that it has gone by just that name and received so much focused attention. As in other areas of philosophy, questions concerning naturalism’s merits are central to recent epistemological debate. While many epistemological theories and positions are agreed by all to exemplify, or to run counter to, naturalistic epistemology (NE), it is difficult to characterize precisely, since “naturalism” is used to refer to a range of positions, commitments, and so on. NE, then, is more a movement or general approach to epistemological theorizing than it is some substantive thesis (/theses). Broadly speaking, however, proponents of NE take the attitude that there should be a close connection between philosophical investigation—here, of such things as knowledge, justification, rationality, etc.—and empirical (“natural”) science. Beyond that, and as detailed below, proponents of NE diverge in how they conceive of that close connection, exactly—whether and to what extent they advocate use of empirical methods, or insist upon the relevance of the results of certain areas of empirical study, or invoke certain recognized “natural” properties, relations, and so on, in their accounts of certain central epistemic phenomena. So too, proponents of NE differ in which science(s) they take to be relevant to epistemological theory—whether it is psychology and/or cognitive science, ethology, cultural studies, evolutionary theory, social theory, or some other area of empirical investigation.