III. Our waking will can only realize or act on such images as it has kept familiarly before it, or such as have been so often recalled that they recur spontaneously. But all the treasures of memory seem to be available to the dream ruler, and with them a loose facile power of grouping them into kaleidoscopic combinations. Thus, if one could imagine a kaleidoscope which at every turn made varied groups of human or other figures in different attitudes, with changing scenery; and then suppose this to be turned round by some simple vital or mechanical action, he would have an idea of the action of dreams. It is probable that the radical function of the dream-power is to prevent images from becoming utterly forgotten or rusty; and by exercising the faculty of facile or chance combination to keep awake in man originality and creativeness. For it is almost certain that, but for the intrusion of this faculty into our waking thoughts, man would become a mere animal, without an idea beyond the joint common appetites, instincts, and emotions of the lowest of his kind. IV. The dream-power intrudes more or less into all waking life. Then it acts, though irregularly, yet in harmony, with conscious will. When it is powerful and has great skill in forming associations of images--and by images I mean, with Kay, "ideas"--and can also submit these to waking wisdom, the result is poetry or art. In recalling strange, beautiful images, and in imagining scenes, we partly lapse into dreaming; in fact, we do dream, though conscious will sits by us all the time and even aids our work. And most poets and artists, and many inventors, will testify that, while imagining or inventing, they abstract the "mind" from the world and common-place events, seek calm and quiet, and try to get into a "brown study," which is a waking dream. That is to say, a condition which is in some respects analogous to sleep is necessary to stimulate the flow and combination of images. This brown study is a state of mind in which images flow and blend and form new shapes far more easily than when Will and Reason have the upper hand. For they act only in a conventional beaten track, and deal only with the known and familiar.