of the first rank—­a Diaz or a Dupre—­that his rendering of her, his picture, would have an agreeable effect, owing to its design or color or both, if it were turned upside down.  Decorative painting in this sense may easily be carried so far as to seem incongruous and inept, in spite of its superficial attractiveness.  The peril that threatens it is whim and freak.  Some of Monticelli’s, some of Matthew Maris’s pictures, illustrate the exaggeration of the decorative impulse.  After all, a painter must get his effect, whatever it be and however it may shun the literal and the exact, by rendering things with pigments.  And some of the decorative painters only escape things by obtruding pigments, just as the trompe-l’oeil or optical illusion painters get away from pigments by obtruding things.  It is the distinction of Diaz and Dupre that they avoid this danger in most triumphant fashion.  On the contrary, they help one to see the decorative element in nature, in “things,” to a degree hardly attained elsewhere since the days of the great Venetians.  Their predilection for the decorative element is held in leash by the classic tradition, with its reserve, its measure, its inculcation of sobriety and its sense of security.  Dupre paints Seine sunsets and the edge of the forest at Fontainebleau, its “long mysterious reaches fed with moonlight,” in a way that conveys the golden glow, the silvery gleam, the suave outline of spreading leafage, and the massive density of mysterious boscage with the force of an almost abstract acuteness.  Does nature look like this?  Who knows?  But in this semblance, surely, she appeared to Dupre’s imagination.  And doubtless Diaz saw the mother-of-pearl tints in the complexion of his models, and is not to be accused of artificiality, but to be credited with a true sincerity of selection in juxtaposing his soft corals and carnations and gleaming topaz, amethyst, and sapphire hues.  The most exacting literalist can hardly accuse them of solecism in their rendering of nature, true as it is that their decorative sense is so strong as to lead them to impose on nature their own sentiment instead of yielding themselves to absorption in hers, and thus, in harmonious and sympathetic concert with her, like Claude and Corot, Rousseau and Daubigny, interpreting her subtle and supreme significance.

* * * * *

Rousseau carried the fundamental principle of the school farther than the others—­with him interest, delight in, enthusiasm for nature became absorption in her.  Whereas other men have loved nature, it has been acutely remarked, Rousseau was in love with her.  It was felicitously of him, rather than of Dupre or Corot, that the naif peasant inquired, “Why do you paint the tree; the tree is there, is it not?” And never did nature more royally reward allegiance to her than in the sustenance and inspiration she furnished for Rousseau’s genius.  You feel the point of view in his picture,