With its Ellsworth Kelly exhibition last year, the Barnes Foundation extended its timeline from its founder's death in 1951 deep into the modern period. Now its show for the British-Nigerian artist Yinka Shonibare makes an even more audacious quantum leap, right to the heart of postmodern thinking, challenging received wisdom about subjects such as colonialism and cultural identity.

The show's title, "Magic Ladders," refers to another prominent theme, that education is the key to success in life. Three new sculptures commissioned especially for this show depict youngsters climbing up library ladders whose rungs are facsimiles of books in Albert Barnes' library.

The sculptures are charming, although their validation of education, particularly of reading - another sculpture shows a young boy reading a book in the manner of Abe Lincoln by the fireside - is less than a cosmic insight.

The ladder sculptures, the reader, a young girl peering through a telescope, and two boys seated at an old-fashioned school desk are complemented by a three-figure tableau of famous Enlightenment thinkers.

Shonibare, 51, who uses a wheelchair because of a spinal affliction, has given each one a handicap. Chemistry pioneer Antoine Lavoisier also sits in a wheelchair, philosopher Immanuel Kant is legless, and the Marquise du Chatelet, translator of Sir Isaac Newton's Principia Mathematica, displays a prosthetic arm.

The artist's explanation for these handicaps is amusingly labored: "I wanted to use [them] as a device for showing how these figures, who were partly responsible for defining otherness in the context of the Enlightenment, could also be 'othered' in the context of disability."

Colonialism gets its comeuppance in an installation that refers to a late-19th-century conference in Berlin at which European nations carved up the African continent. Fourteen headless figures (except for the "students," whose heads are globes, all Shonibare's figures are headless, and thus anonymous) sit around a conference table imprinted with a map of the unfortunate continent.

So far, so bland. But now we introduce the exhibition's critical element, one that not only gives Shonibare's art its principal visual interest but also clarifies his philosophical agenda.

This is his use of colorfully patterned "African cloth" for all the clothing and even for the upholstery and wall covering for the simulation of a Victorian philanthropist's parlor.

These "African" textiles are printed in the Netherlands by a wax-resist process developed in what is now Indonesia, formerly a Dutch colony. So Shonibare is warning us, tongue in cheek, against blindly accepting cultural stereotypes.

As with the anodyne education sculptures, he does this in a cheerful, pleasing way. The sculptures, and especially the ancillary objects in the installations, are beautifully made - by assistants and fabricators - even if the mannequins, especially as posed, resemble fashion dummies one might see in a department-store window.

Even the anticolonialist message is soft-pedaled; Shonibare isn't a ranter or a bomb-thrower but a satirical subversive. His thinking isn't easy to decipher, in large part because the sculptures and installations are so attractive and seemingly benign.

Which brings us back to the fabrics, which unify the various conceptual strands of his art and give the figures whatever visual interest they have. Subtract the commercially printed fabrics and there isn't much of anything to look at or think about.

The Barnes show, relatively small at 17 works, is Shonibare's second appearance in Philadelphia. He was a resident artist at the Fabric Workshop and Museum in 2002. The Workshop has installed a sculpture that he created then, Space Walk, in the window of its Temporary Contemporary gallery at 1222 Arch St.

You might ask, as I did, how an artist like Shonibare relates to the Barnes Foundation's fabled permanent collection. Or even whether he does.

Judith F. Dolkart, the foundation's chief curator, anticipated the question. The small book produced for the exhibition constructs an elaborate rationale that connects this art with Albert Barnes' interest in, and ruminations about, education.

The book even includes facsimiles of letters Barnes wrote in which he expounds on his theories and beliefs. If there really were an inescapable connection, none of this exposition would be necessary.

I'm not forgetting that the Barnes was founded as a school, and that for nearly nine decades its primary mission was art instruction. Now it's a museum with a school, and its focus has changed.

To prosper in its Parkway incarnation, the foundation must broaden its constituency, and Shonibare helps with that, especially with the African American community. It also must offer a steady stream of special attractions that generate a continual buzz of activity and freshness.

Oddly, the next attraction in the special exhibitions gallery isn't going to project Barnes visitors further toward Art Now - it's going to U-turn back to the collection's roots.

That show, opening June 22 and running through Sept. 22, is titled "The World Is an Apple: The Still Lifes of Paul Cezanne." This in a museum that owns 69 Cezannes, 16 of them still lifes.

The international loan show is being organized by the Art Gallery of Hamilton, Ontario. It will contain about 18 Cezannes and some related paintings by other artists.

Holy coals to Newcastle, I can't wait.

 "Magic Ladders"

Through April 21 at the Barnes Foundation, 20th Street and the Parkway.

Hours: 10 a.m. to 6 p.m. Wednesdays and Thursdays, and Saturdays through Mondays; 10 to 9 p.m. Fridays. Closed Tuesdays.

Admission: $22, $20 for visitors 65 and older, $10 for students with ID and visitors 6 through 18.

Information: 215-278-7000 or www.barnesfoundation.org. EndText

"Art" by Edward J. Sozanski and "Galleries" by Edith Newhall appear in alternating weeks.