Again, Mr Ruskin, writing of the street in the centre of another landscape by Nicolas Poussin, indicates it with emphasis:--'the street in the centre of the really great landscape of Poussin (great in feeling, at least) marked 260 in the Dulwich Gallery,' The criticism with which Mr Ruskin follows up this praise is so perfect a bit of word-painting, that I cannot refrain from writing it down here. 'The houses are dead square masses, with a light side and a dark side, and black touches for windows. There is no suggestion of anything in any of the spaces, the light wall is dead grey, the dark wall dead grey, and the windows dead black. How differently would nature have treated us. She would have let us see the Indian corn hanging on the walls, and the image of the Virgin of the tiled eaves, and the deep ribbed tiles with the doves upon them, and the carved Roman capital built into the wall, and the white and blue stripes of the mattresses stuffed out of the windows, and the flapping corners of the neat blinds. All would have been there; not as such, not like the corn, nor blinds, nor tiles, not to be comprehended nor understood, but a confusion of yellow and black spots and strokes, carried far too fine for the eye to follow; microscopic in its minuteness, and filling every atom and space with mystery, out of which would have arranged itself the general impression of truth and life.' Once more, Mr Ruskin freely admits that 'all the landscape of Nicolas Poussin is imagination.'
Mr Ruskin's first definition of ideal landscape is in this manner. Every different tree and leaf, every bud, has a perfect form, which, were it not for disease or accident, it would have attained; just as every individual human face has an ideal form, which but for sin and suffering it would present: and the ideal landscape-painter has realized the perfect form, and offers it to the world, and that in a sense quite distinct from the fallacy of improving nature.
But I wish to take my readers further into imaginative landscape, and to show it to them, if possible, under additional lights. I despair of succeeding if I cannot do it by one or two simple examples. In passing through a gallery we may stop before a picture to be struck, almost startled, by the exact copy which it presents of some scene in nature; how like the clouds in the sky, the leaves on the trees, the very plumage of the birds! But pass on to another picture which may or may not have the same exact likeness, and we are possessed with quite another feeling; instead of being merely surprised by the cleverness of the imitation, we feel a thrill of delight at a reproduction of nature. In this picture there are not only the clouds we remember, but we can almost feel the shadows which they cast, and the air which stirs them. These tree-leaves are not only green, or yellow, or russet, they are tender, or crisp living leaves. One half expects to see the birds' throats swell, and hear the sweetness or the shrillness of their songs.