“On F or G they constructed celestial harmonies,--as harmonies,--combinations evolved from the chorus of F or G and their minor correlatives. “This is pure music as distinguished from airs,--commonplace and vulgar in themselves, but interesting from their associations,--as, for instance, ‘Yankee Doodle’, or ‘Partant pour la Syrie.’ “Art should be independent of all clap-trap, should stand alone, and appeal to the artistic sense of eye or er, without confounding this with emotions entirely foreign to it, as devotion, pity, love, patriotism, and the like. All these have no kind of concern with it; and that is why I insist on calling my works ‘arrangements’ and ‘harmonies.’”[33] And concerning the portrait of his mother, which nearly every one admires for the subject while few pause to consider the color, he wrote: “Take the picture of my mother, exhibited at the Royal Academy as an ‘Arrangement in Gray and Black.’ Now, that is what it is. To me it is interesting as a picture of my mother; but what can or ought the public to care about the identity of the portrait?”[34] Within these few lines are contained Whistler’s whole philosophy of art, his convictions and his intentions; the words are so plain a child may read and comprehend their meaning, and yet people will not understand him. Whistler’s art was purely sensuous, as the finest music is sensuous. He had no interest whatsoever in the many problems of life and death, in the story of any person or the traditions of any place. He had less interest in the associations connected with Old Battersea Bridge than the boatman lazily floating by; but at certain hours and under certain conditions, at twilight or at dusk, or in the fog, it made a long, tremulous line which pleased him, and he painted it. The fact that the Thames bounds English history was of no consequence to him; but the muddy river between lines of buildings and wharves and shipping, and covered by boats and crossed by bridges, furnished him endless compositions in line and color. The glory and the romance of Venice made no impression on his art; but in out-of-the-way places, where others saw nothing, he found scenes which inspired his etchings. As an etcher and a lithographer Whistler played with the mystery of line, as in painting he played with the mystery of color. There is an art of pure line as there is an art of pure form and of pure color. It is just as possible to make a lot of meaningless lines which please the eye in their curves and endless variety as it is to please the eye with combinations of colors. Decorative patterns and designs, aside from color, are simply line harmonies. A child loves to make straight and round and curved lines upon slate or paper. The eye follows lines with a delight akin to that taken in form and color.