"Appreciations: American Impressionist Paintings and Related Works from the Phillips Collection" is a dull -- but telling -- show. Most of the 70 pictures in it have lived for years in storerooms. It is easy to see why. They are timorously modernist and entirely unthreatening. They represent the foundation from which the Phillips Collection grew.

Though Duncan Phillips (1886-1966) is remembered as the man who founded the world's first museum of modern art, he was not always daring. He bought many of these paintings before he found his eye for art.

Phillips was, when young, something of an art prig. He haughtily dismissed the 1913 Armory Show as "quite stupefying in its vulgarity." Its modernists, he wrote, were "anarchists, not artists." He was particularly offended by van Gogh and Ce'zanne. He condemned them both as "unbalanced fanatics." When, in 1918, he founded his museum, he vowed to "guard its doors against the intrusion of wild, unbalanced radicals."

Like so many other young men of his class, Phillips then preferred pictures of the sort included in this show.

They are rigorously genteel. Most of them portray country meadows, blooming trees, or ladies in long dresses wandering through glens. They are the sort of pictures that wealthier Americans hung amidst the bric-a-brac and brown plush of their parlors. Their central subject is the landscape. Their style is a watered-down one borrowed from the French.

These are plein-air paintings. Like their Parisian teachers, the Americans represented were believers in immediacy. They took their paint boxes and easels out into the countryside, or into city parks, and sought to capture on their canvases the scene before their eyes. They tended to paint quickly, and their haste shows in their brushwork.

Ernest Lawson's "Spring Morning, Washington Bridge" might well have been completed in a single session. His view of the river (it could be the Potomac) and of the young trees on its bank is the sort of view devoted Sunday painters still produce today. Childe Hassam's "Washington Arch, Spring" (1890) is another morning picture -- horse-drawn cabs and street-sweepers seen in Greenwich Village. A number of these views -- Maurice Prendergast's street scenes of Paris and of Rome, or Theodore Robinson's quick summary of the landscape near Monet's home at Giverny -- were produced abroad. But John Henry Twachtman, who is among the finest of the artists represented, felt, as he grew older, little need to travel. He was satisfied with painting the cycle of the seasons and the always-shifting light around his Massachusetts home.

These paintings don't exaggerate. They are relatively free of literary subject matter and allegorical allusion -- painters who could concentrate on the scenes before them were considered avant-gardists in the 1890s. But the pictures on display here no longer seem as daring as they once appeared. Their modernism nowadays looks a little shallow. Their surfaces look French, but underneath that stylish shimmer one detects a solid carpentry, an affection for hard fact, that is peculiarly American.

The Impressionist style had been a hit in the United States since Paul Durand-Ruel, the Paris dealer, introduced it to New York in 1886. Impressionism meant color, impressionism meant modernity -- New York, even then, was delighted with the new. And -- as troops of lesser, expatriate Americans were delighted to discover -- pictures in the Impressionist mode were not that hard to paint. Why bother with high finish if speed was just as fashionable? Why smooth out your brush strokes when discrete daubs would do?

"It sounds like a paradox," wrote Henry James in 1893, "but it is a very simple truth, that when we look for American art we find it mainly in Paris. When we find it out of Paris, we at least find a great deal of French in it." Such American painters as Robinson, Twachtman, J. Alden Weir and Hassam had already made the pilgrimage to Paris when they produced the paintings included in this show.

Duncan Phillips and his brother, James Laughlin Phillips, began collecting seriously -- with their parents' money -- in early 1916. Their collection would be formed, the brothers wrote their parents, "along the same lines" followed "by scores of the most successful and conservative businessmen -- except in two respects. 1. Our suggestions are far more conservative. 2. The average picture collector has not nearly the knowledge, experience and appreciation of Art that Duncan and I possess." They were wrong about their knowledge. Neither Duncan, nor his brother, who died of flu in 1918, was a cunning connoisseur. But they were right about their conservatism. It dominates this show.

Duncan, at the start, preferred buying pictures painted in the styles of the well-thought-of French. Ernest Lawson's "Spring Morning, Washington Bridge," could not have been painted had the artist not immersed himself in the lessons of Corot. Reynolds Beal's "Beach Ponies" owes a debt to the style of van Gogh. Not all the pictures here are examples of the timid. "Gray Day, Goochland, Va.," an 1884 canvas by George Inness, bought by Duncan's father, is, though only distantly "Impressionist," a work of powerful originality. There are two fine Prendergasts on view, and one superb Twachtman. "Hide and Seek," an 1888 William Merritt Chase that is among the nicest pictures at the Phillips, also lifts the level of this rather tepid show.

Though his taste would alter radically, Duncan Phillips would never lose his love for free, expressive color -- or for the art of France. The present exhibition is the first of four "Appreciations," all drawn from his collection, which will be seen in Washington while the Phillips' best-known pictures are on extended tour. That traveling show, which seemed, at first, our loss, has proved to be our gain. The most memorable facet of the Impressionist exhibit is that it is a partial portrait of the late Duncan Phillips. It shows us where he started -- and increases our admiration for how far he progressed. It closes Nov. 15.