To turn to the consideration of Movement in art, we find that the power of rendering this characteristic of life is shared by Music only with Dancing and with Literature. By movement in an art-work I mean movement whose sequences have proportion and design, progressing by stages linked to each other through natural and organic associations towards a significant conclusion. In nature, movement can be immensely varied in character. It can be slow or swift, rough and laboured or smooth and fluent, massive and voluminous or arrowy and intense; it can leap or undulate, march or dance, soar or swoop, and each of these kinds of movement means something to the spirit of man. All these Music controls, and can order and harmonize at will. It can represent that in the movement of nature which goes beyond and overmasters Rhythm; for Rhythm in itself does not involve Progression; in fact, a perfect rhythm would forbid it. If Action and Reaction were always precisely equal, we should have a universe as stationary as a spinning top—it might be in vehement action, but it would never develop into something new.[183] Music by its complete command of the phases of movement can illustrate the progressive force, the life-impulse in nature, and this not merely by symbols and intellectual forms, but by playing directly on the nervous system as a harp-player on the strings of his instrument. No art is more sensuous than Music, and none more abstract, more removed from what are called realities, in the substance of what it conveys. Its entire independence of objects of sense as given in experience, combined with its mastery of the inner law, the spiritual significance, of life has led to its being ranked by some as the highest of the arts. I doubt if such comparisons are profitable, but it is easy to recognize a sense in which Schopenhauer speaks truth when he says that the other arts deal with the shadows of life, Music, however, with its essence.[184] Let us now consider the Representative Arts in the light of the principle which we are trying to establish. Since they depend on the portrayal of objects actually found in nature and not created by the artist, their relation to life is obvious. There are, however, some minor problems of great interest and intricacy connected with them, and these we must briefly touch on.