Besides serving as a fitting memorial tribute to Marc Chagall, who died at 97 in March, the great retrospective exhibition of his works at the Museum of Art here provides two memorable pleasures: It enables the viewer to relive, in the most direct, authentic fashion, the exhilarating burst of creativity during the years 1911 and 1912 that announced the arrival of a major 20th-century artist; and, after this astonishing early crescendo, allows visitors to dwell at length in the glow of an artistic world that, even after seven decades of familiarity, time and again surprises and pleases with its invention, coherence and beauty.

Chagall is one of our time's best-known and best-loved artists. We all know the fundamental elements of the universe he created -- the fiddlers, flowers, lovers, animals, angels, synagogues and cityscapes that populate it; the floating, "illogical" space and the sense of simultaneous discovery that enliven the stories he tells so well; the deeply humane and profoundly religious convictions that imbue his art with its special significance and appeal.

There is a sense in which we think we know Chagall so well we take him for granted. But much of our knowledge, and consequently our appreciation of his art, has been contaminated by the second-rate lithographs that flooded the market in his last few decades. And the fact that Chagall maintained his special voice and esthetic strategy from those early years in Paris until the very end -- a dreamy 1984 painting of floating lovers chronologically closes this show -- created problems of evaluation.

His later art, especially when seen in reproduction, sometimes seemed a pastiche of past achievements.

The great contribution of an exhibition such as this one, then, is to take these issues out the realm of received knowledge and to reacquaint us with the works themselves.

This proves to be a very different matter from art-world talk, and the show may do for Chagall what the Guggenheim Museum's show of Picasso's late works a few years back did for that master: that is, revive the argument about the late works and, ultimately, revive the reputation. (This is, admittedly, chiefly a problem for critics. The public loved the late Chagall, and Chagall loved the public.)

Chagall was, right up to the end, nothing less than a magnificent painter. Even that 1984 painting -- with its familiar floating lovers, still-life vase of flowers, tiny cart and horse, foreground townscape -- is a stunning piece of work. The richness of the colors and the vigor of the brushwork are those of a master working with utter self-confidence and at peak form. The familiar image is fresh because the artist willed it so, and renders criticism useless.

If the elder Chagall often was able to quote himself successfully, he also was able to stun us with his ambition. Few paintings in the exhibition are so powerful in form and content as "The Fall of Icarus" (1975) or "The Large Circus" (1968). In both large pictures the great colorist uses grays and blacks to telling effect and both have a somber undertone that contradicts the cliche'd image of the late Chagall solely as a prophet of peace and joy.

"Icarus," with the precipitously falling hero being observed with strange matter-of-factness by a huge crowd of peasants from Chagall's Russian boyhood (and his own early works), gives human dimension to the myth. It comprises a provocative, ambiguous rumination on the themes of ambition, pride and failure. "Circus" surprises because, despite the subject, the mood is tragic. The central figures are a winged woman and a mythical beast levitating above another mythical creature (a horse with the head of a cock) and circus musicians. The music they play clearly is mournful.

As Susan Compton notes in her catalogue entry, "Gone are the tumblers of the big top, all simple gaiety in the sawdust ring: here, instead, Chagall depicts some more profound drama in which man is engaged, poised between Heaven and Hell, ever torn apart by the twin desires of hatred and love, and ever seeking a reconciliation."

Chagall was born in 1887 in Vitebsk, a provincial city in which his relatives, like all Jews there, were kept in a form ofsemiservitude -- they weren't slaves, but neither were they free -- by the anti-Semitic laws of czarist Russia. The young artist escaped literally to St. Petersburg (now Leningrad) and imaginatively, as critic John Russell has observed, in his art, by recreating a Vitebsk where the magic of human flight was possible. Late in 1910, with help from a patron, the impecunious artist went to Paris, where he lived with squalid poverty and artistic inspiration for 3 1/2 years.

There is nothing more exciting in this exhibition than seeing the astounding transformation of the awkward provincial artist, aping styles from distant Paris, into the sophisticated painter and weaver of magical tales. Among the early works from his Russian days there are a few that show Chagall's seriousness and originality (he insisted on narrative subjects in the context of an avant-garde ambition), but there is nothing to foretell the explosion that would take place almost as soon as he set foot in Paris.

Liberated by the intellectual atmosphere of the prewar capital of European art, by the spatial investigations of the Cubists, and by the color of the Fauves and the Orphists, Chagall right away began painting masterpieces. This great show contains many of his best canvases from these years, loaned by museums in Europe and the United States: "I and the Village" (1911), "Half Past Three (The Poet)" (1911), "Homage to Apollinaire" (1911-1912), "The Soldier Drinks" (1911-1912), "The Cattle Dealer" (1912), "The Fiddler" (1912-13), "The Flying Carriage" (1913) and "The Violinist" (1911-1914).

Chagall's achievement ranks with other epochal artistic transformations in prewar Paris (those of Matisse and of Picasso and Braque, for instance), even though his output was extremely uneven. It is amazing to see the above-named paintings hanging next to awkward, tentative works created at the same time. When Chagall returned to Russia in 1914, to be trapped there by the outbreak of war, he began a long period of serious self-assessment and self-assimilation. When he reappeared in France in 1923 he was a fully mature artist.

The Japanese have an official custom of honoring living artists by naming them "national treasures." This beautifully selected exhibition, containing nearly 200 works and fully exploring every aspect of his achievement (including his great book illustrations, his awesome works for the theater and his later, superb efforts in stained glass), provides sufficient evidence for us to christen Chagall, the Russian Jew and Parisian painter, a world treasure.

The exhibition, organized by Compton for the Royal Academy of Arts in London (where it premiered) and the Philadelphia Museum, will continue in Philadelphia through July 7, after which it will be disbanded. Admission is by ticket only, available at the museum (for $4) or through Philadelphia Ticketron outlets ($5.25). Group visits can be arranged through the Museum Guides office at 215-787-5450. The museum is open from 10 a.m. to 5 p.m. Tuesdays through Sundays and on Memorial Day andthe Fourth of July. Closed Mondays except Memorial Day.

Compton's excellent, amply illustrated catalogue is for sale at the Museum Shop ($12.95) or by mail order ($15.45) from the museum, Parkway at 26th Street, Philadelphia 19101.