13. Returning now to the very elementary form in which the appeal to our æsthetic virtue is made in our breakfast-plate, you notice that there are two distinct kinds of pleasantness attempted. One by hues of color; the other by proportions of space. I have called these the musical elements of the arts relating to sight; and there are indeed two complete sciences, one of the combinations of color, and the other of the combinations of line and form, which might each of them separately engage us in as intricate study as that of the science of music. But of the two, the science of color is, in the Greek sense, the more musical, being one of the divisions of the Apolline power; and it is so practically educational, that if we are not using the faculty for color to discipline nations, they will infallibly use it themselves as a means of corruption. Both music and color are naturally influences of peace; but in the war trumpet, and the war shield, in the battle song and battle standard, they have concentrated by beautiful imagination the cruel passions of men; and there is nothing in all the Divina Commedia of history more grotesque, yet more frightful, than the fact that, from the almost fabulous period when the insanity and impiety of war wrote themselves in the symbols of the shields of the Seven against Thebes, colors have been the sign and stimulus of the most furious and fatal passions that have rent the nations: blue against green, in the decline of the Roman Empire; black against white, in that of Florence; red against white, in the wars of the Royal houses in England; and at this moment, red against white, in the contest of anarchy and loyalty, in all the world.
14. On the other hand, the directly ethical influence of color in the sky, the trees, flowers, and colored creatures round us, and in our own various arts massed under the one name of painting, is so essential and constant that we cease to recognize it, because we are never long enough altogether deprived of it to feel our need; and the mental diseases induced by the influence of corrupt color are as little suspected, or traced to their true source, as the bodily weaknesses resulting from atmospheric miasmata.