 Empirical psychologists have drawn a contrast between implicit and explicit memory or knowledge, but this distinction does not map neatly onto the implicit/explicit belief distinction described in Section 2.2.1. In the psychologists’ sense, explicit memory involves the conscious recollection of previously presented information, while implicit memory involves the facilitation of a task or a change in performance as a result of previous exposure to information, without, or at least not as a result of, conscious recollection (Schacter 1987; Schacter and Tulving 1994; though see Squire 2004). For example, if a subject is asked to memorize a list of word pairs—bird/truck, stove/desk, etc.—and is then cued with one word and asked to provide the other, the subject’s explicit memory is being tested. If the subject is brought back two weeks later, and has no conscious recollection of most of the word pairs on the list, then she has no explicit memory of them. However, implicit memory of the word-pairs would be revealed if she found it easier to learn the “forgotten” pairs a second time. Knowledge that is “implicit” in this sense will normally not be implicit in the sense of the previous subsection (if it were swiftly derivable from what one explicitly believes, presumably one could answer the test questions correctly); it’s also at least conceptually possible that some such psychologically implicit knowledge may be stored stored “explicitly” in the sense of the previous subsection.