 Substantive NE too is a rejection of any very strong version of the autonomy of epistemology  (b),  understood as a claim about its subject matter. Further, some critics have contended that externalism is, as such, ill-equipped to provide useful guidance to epistemic agents, at least of the first-personal reason-guiding variety. In this way, it has been thought, substantive naturalistic views might run afoul of  (c),  understood as a claim about a specific type of normative guidance or improvement (see, e.g., Kaplan 1994, BonJour 1994). An important sub-theme within substantive NE, as Goldman notes, is “descriptive realism as opposed [to] idealization” (1994, p. 305), not merely for accuracy’s sake, but so as to ensure responsiveness to the principle that “ought implies can” (ibid.). For some, this is the primary motive for adopting a naturalistic approach: