As music is the poetry of sound, so is painting the poetry of sight, and the subject-matter has nothing to do with harmony of sound or of colour. The great musicians knew this. Beethoven and the rest wrote music — simply music; symphony in this key, concerto or sonata in that... Art should be independent of all claptrap — should stand alone, and appeal to the artistic sense of eye or ear, 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.'

Propositions, 2 - 'The Gentle Art of Making Enemies' (1890)