  Like Locke, Hume holds that ideas have no continued existence. And so, Reid argues, Hume cannot claim that a numerically identical idea can reappear. In addition, Hume’s account faces the same circularity objection as Locke’s. Hume accounts for memory by appealing to an idea that is qualitatively similar to, but less forceful and vivacious than a previous idea. But the ability to judge qualitative similarity and degrees of force and vivacity between present ideas and past impressions presupposes memory.