ing the same effort or progressing with the same rapidity. The first, requiring only the intervention of memory, takes place from the outset of our experience; the second goes on indefinitely without ever reaching its goal. The first issues in the formation of stable images, which in their turn are stored up in memory; the second comes out in representations that are unstable and evanescent. We must dwell on this last point, for we touch here an essential problem of mental life.
The essence of the general idea, in fact, is to be unceasingly going backwards and forwards between the plane of action and that of pure memory. Let us refer once more to the diagram we traced above. At S is the present perception which I have of my body, that is to say, of a certain sensori-motor equilibrium. Over the surface of the base AB are spread, we may say, my recollections in their totality. Within the cone so determined the general idea oscillates continually between the summit S and the base AB. In S it would take the clearly defined form of a bodily attitude or of an uttered word; at AB it would wear the aspect, no less defined, of the thousand individual imagesAnd the general idea is always in movement between the plane of action and that of pure memory. into which its fragile unity would break up. And that is why a psychology which abides by the already done, which considers only that which is made and ignores that which is m the making, will never perceive in this movement
