  This question is central for Quine’s scientific naturalism in general. An answer would show that that world-view can accommodate an account of human knowledge. If no answer is available, that world-view is cast in doubt. For these purposes it is perhaps enough if Quine can sketch an account, compatible with his naturalistic view, of how we might acquire the knowledge which we take ourselves to have, whether or not it is correct in detail. (See Quine 1990c, 291.)