 In “Introduction to Metaphysics,” Bergson gives us three images to help us think about the duration and therefore qualitative multiplicities (The Creative Mind, pp. 164–65). The first is that of two spools, with a tape running between them, one spool unwinding the tape, the other winding it up. (During his discussion of Bergson, Heidegger focuses on this image in his 1928 The Metaphysical Foundations of Logic.) Duration resembles this image, according to Bergson, because, as we grow older, our future grows smaller and our past larger. The benefit of this image is that it presents a continuity of experiences without juxtaposition. Yet, there is a drawback: because a tape moves between the two spools, the image presents the duration as being homogeneous, as if one could fold the tape back over its other parts, as if the tape were super-posable, implying that two moments in consciousness might be identical. Yet, as Bergson says, “no two moments are identical in a conscious being” (The Creative Mind, p. 164). Duration, for Bergson, is continuity of progress and heterogeneity; moreover, thanks to this image, we can also see that duration implies a conservation of the past. Indeed, for Bergson and this is the center of his truly novel idea of memory, memory conserves the past and this conservation does not imply that one experiences the same (re-cognition), but difference. One moment is added onto the old ones, and thus, when the next moment occurs, it is added onto all the other old ones plus the one that came immediately before. In comparison, therefore to the past collection of moments, it cannot be the same as the one immediately before, because the past is “larger” for the current moment than it was for the previous moment. Although Bergson does not say this, one might say that Tuesday is different from Monday because Monday only includes itself and Sunday, while Tuesday includes itself, Monday, and Sunday. This first image, therefore, implies that duration is memory: the prolongation of the past into the present. We shall return to the question of memory below.