flects the exact adaptation of our nervous system to the present situation, did not set aside all those among the past images which cannot be coordinated with the present perception and are unable to form with it a useful combination. At most, certain confused recollections, unrelated to the present circumstances, may overflow the usefully associated images, making around these a less illuminated fringe which fades away into an immense zone of obscurity. But suppose an accident which upsets the equilibrium maintained by the brain between the external stimulation and the motor reaction, relax for a moment the tension of the threads which go from the periphery to the periphery by way of the centre, and immediately these darkened images come forward into the full light: it is probably the latter condition which is realized in any sleep wherein we dream. Of these two memories that we have distinguished, the second, which is active or motor, will, then, constantly inhibit the first, or at least only accept from it that which can throw light upon and complete in a useful way the present situation: thus, as we shall see later, could the laws of the association of ideas be explained.—But, besides the services which they can render by associating with the present perception, the images stored up in the spontaneous memory have yet another use. No doubt they are dream-images; no doubt they usually appear and disappear independently of our will; and
