 Empiricists see both memory and imagination as drawing on preserved sense impressions. Identifying a marker for the distinction between memory and mere imagination is therefore central to the empiricist theory of remembering, and Hume ([1739] 2011) suggested two such markers. First, he suggested that memory and imagination may be distinguished by the latter’s higher degree of flexibility: memory respects the order and form of the subject’s original impressions, whereas imagination does not. This suggestion appears to be unworkable. Hume himself acknowledged that degree of flexibility cannot be employed as a first-person memory marker, since the subject has no means of comparing a current apparent memory to an earlier sense impression. And degree of flexibility fares no better as a third-person memory marker, unless a very extreme form of preservationism is assumed. Generationists, who conceive of remembering as an active, constructive process, are bound to reject a view of memory on which it is characterized by inflexibility. Moderate preservationists likewise acknowledge that remembering is often highly flexible; for example, they may acknowledge that one can remember the elements of an event in an order other than that in which one experienced them (Bernecker 2008).