The root of the difficulty lies in this slippery phrase, Nature. We talk of the facts of Nature, meaning the existence now and here of the hills, sky, trees, etc., as if these were fixed quantities,--as if a house or a tree must be the same at all times and to everybody. But in a child's drawing we see that these things are not the same to us and to him. He is careful to give the doors and windows, the chimneys with their smoke, the lines of the fence, and the walk in front; he insists on the divisions of the bricks and the window-panes: but for what is characteristic and essential he has no eye. He gives what the house is to him, merely _a house_ in general, any house; it would not help it, but only make the defect more prominent, to straighten and complete the lines. An artist, with fewer and more careless lines, would give more of what we see in it; and if he be a man of high power, he may teach us in turn the limitation of our seeing, by showing that the vague, half-defined sentiment that attaches to it has also a visible expression, if we knew where to look for it. We hear people say they know nothing of Art, but that they can judge as well as anybody whether a picture is like Nature or not. No doubt Giotto's contemporaries thought so, too, and they were grown men, with senses as good as ours; but we smile when Boccaccio says, "There was nothing in Nature that Giotto could not depict, whether with the pencil, the pen, or the brush, so like that it seemed not merely like, but the thing itself." We smile superior, but Giotto had as keen an eye and as ready a hand as any man since. The lesson is, that we, too, have not come to the end of even the most familiar objects, but that to another age our view of them may seem as queer as his seems to us. For the facts in Nature are not fixed, but transcendental quantities, and their value depends on the use that is made of them. It is in this direction that the artist's genius avails; his skill in execution is secondary and incidental. The measure of his ability is the depth to which he has penetrated the world of matter, not the number or the accuracy of his facts. Every landscape wears many faces, as many as there are men and different moods of the same man. To one the forest is so many cords of wood; to another, an arboretum; to another, a workshop or a museum; to another, a poem. What each sees is there; the forest exists for beauty and for firewood, and lends itself indifferently to either use.