This rough diagram will be sufficient to explain my thought respecting the relative degree to which the art dealing with linear form, that dealing with colour and that dealing with light, with the medium in which form and colour are perceived; is each respectively bound to be idealistically or realistically decorative. Now painting was æsthetically mature, possessed the means to achieve great beauty, at a time when of the three modes of representation there had as yet developed only those of linear form and colour; and the very possibility and necessity of immediately achieving all that could be achieved by these means delayed for a long time the development of the third mode of representation: the representation of objects as they appear with reference to the light through which they are seen. A beginning had indeed been made. Certain of Correggio's effects of light, even more an occasional manner of treating the flesh and hair, reducing both form and colour to a kind of vague boss and vague sheen, such as they really present in given effects of light, a something which we define roughly as eminently modern in the painting of his clustered cherubs; all this is certainly a beginning of the school of Velasquez. Still more so is it the case with Andrea del Sarto, the man of genius whom critics love to despatch as a mediocrity, because his art, which is art altogether for the eyes, and in which he innovated more than any of his contemporaries, does not afford any excuse for the irrelevancies of ornamental criticism; with him the appearance of form and colour, acted upon by light, the relative values of which flesh and draperies consist with reference to the surrounding medium, all this becomes so evident a preoccupation and a basis for decorative effects, as to give certain of his works an almost startling air of being modern. But this tendency comes to nothing: the men of the sixteenth century appear scarcely to have perceived wherein lay the true excellence of this "Andrea senza errori," deeming him essentially the artist of linear perfection; while the innovations of Correggio in the way of showing the relations of flesh tones and light ended in the mere coarse gala illuminations in which his successors made their seraphs plunge and sprawl. There was too much to be done, good and bad, in the way of mere linear form and mere colour; and as art of mere linear form and colour, indifferent of all else, did the art of the Italian Renaissance run to seed.