at the same time.—Whence comes it that it has been possible to misunderstand so simple, so evident a truth, one which is, moreover, the very idea of common sense?
The reason lies simply in the fact that philosophers insist on regarding the difference betweenBut pure memory, in which each unique moment of the past survives, is essentially detached from life. actual sensations and pure memory as a mere difference in degree, and not in kind. In our view the difference is radical. My actual sensations occupy definite portions of the surface of my body; pure memory, on the other hand, interests no part of my body. No doubt, it will beget sensations as it materializes; but at that very moment it will cease to be a memory and pass into the state of a present thing, something actually lived; and I shall only restore to it its character of memory by carrying myself back to the process by which I called it up, as it was virtual, from the depths of my past. It is just because I made it active that it has become actual, that is to say, a sensation capable of provoking movements. But most psychologists see in pure memory only a weakened perception, an assembly of nascent sensations. Having thus effaced, to begin with, all difference in kind between sensation and memory, they are led by the logic of their hypothesis to materialize memory and to idealize sensation. They perceive memory only in the form of an image; that is to say, already embodied in nascent sensations. Having thus attributed to it that which is essential to sensa-
