As in all ensembles, the east wall of Room 18 features a grouping of disparate objects from a range of cultures and traditions †including fine art, craftwork and utilitarian items †that form a unit through their formal affinities. The brightly decorated, rust-orange cupboard, 1828, made in central Pennsylvania’s Mahantongo Valley in the workshop of Michael Braun, sets the tone for the ensemble that includes a red-haired Modigliani model to the far right and candlesticks atop the cupboard presaging the background forms of Matisse’s “Reclining Nude†above and American Charles Demuth’s masts and chimneys to the right and left.

After years of controversy and litigation, the Barnes Foundation, one of the world’s great collections of Modern art, opened in its new location in downtown Philadelphia on May 19. Assembled by the eccentric Dr Albert Barnes and hung in idiosyncratic “ensembles” in a suburban Merion mansion in 1925, the trove was by its owner’s will to remain exactly as it was after his death.

A decade ago, when the foundation’s board, frustrated by limits on hours and attendance and short on finances, announced plans to relocate, many objected that such a move would be contrary to Barnes’s wishes and would undermine the integrity of his singular vision. Protests, court actions and much anguish ensued until the move to Central City Philadelphia finally got the green light. The result is a pleasant revelation to many former naysayers.

The Barnes’ convenient location ensures enhanced public access, the new building has amenities its former quarters lacked, the collection has been hung in identical galleries exactly as Barnes mandated, and modern lighting makes the pictures come alive. Remarkably, the design by Tod Williams Billie Tsien Architects re-creates the suburban building and its 24 galleries with pinpoint fidelity to Barnes’s wishes.

The resurrected Barnes, resembling the original white, Modernist design, is set within a larger structure that offers such amenities as a 150-seat auditorium, café, retail shop, a 5,000-square-foot temporary exhibition gallery and expanded educational and conservation facilities, as well as a garden court and outdoor sculpture.

The 93,000-square-foot building housing the Barnes Foundation, astutely designed by Tod Williams Billie Tsien Architects, includes within it a 12,000-square-foot gallery that replicates the dimensions and shapes of the original Merion spaces. The remaining area provides new facilities for education, temporary exhibition and visitor amenities. Whether viewed by day or night, the 4½-acre site makes a spectacular addition to Philadelphia’s Museum Row on Benjamin Franklin Parkway.

Paintings and other artworks hang in symmetrical ensembles with little seeming relationship to each other, interspersed with all manner of wrought iron hinges, ladles, locks and other objects on tan burlap walls. Whereas galleries in Merion tended to be dark and inhospitable to the art, a state-of-the-art lighting system †using both natural and artificial illumination †makes the artwork look better than ever before.

Barnes (1872‱951) grew up in modest circumstances in Philadelphia, graduated from the University of Pennsylvania Medical School and, while working for a pharmaceutical company, co-invented the antiseptic drug Argyrol, which became the basis of his fortune. After marrying dedicated horticulturalist Laura Leggett around the turn of the century, the couple built a home in suburban Merion.

Running the A.C. Barnes [pharmaceutical] Company in Philadelphia until 1929, Barnes organized daily, two-hour seminars for his employees, in which they discussed the writings of John Dewey, William James and George Santayana, and examined original works of art. That interest in art led to a renewed friendship with Barnes’s old high school mate, painter William Glackens.

In 1912, Barnes, who said Glackens had “the best eyes in America,” sent his friend to Europe to procure works by contemporary French artists. Several weeks and $20,000 later, Glackens returned to Philadelphia with 33 paintings, including several Renoirs, a Cezanne, a Picasso and a van Gogh †works that formed the nucleus of Barnes’s collection and influenced his artistic and educational theories.

Drawn to Italian artist Giorgio de Chirico’s stark, surreal depictions of peopleless landscapes in which antiquity and modernity often collided, Barnes collected several of his works, and had him paint this introspective portrait in 1926. It captures some of pent-up energy and iron will of the maverick, self-made millionaire whose irascible temper was as strong as his visionary commitment to Modern art.

Visiting the Paris salon of Gertrude (with whom he did not get along) and Leo (with whom he enjoyed cordial relations) Stein, Barnes was exposed to the work of such avant-garde artists as Henri Matisse and Picasso. Barnes developed a network of artists, agents and dealers, although he made his own decisions. For decades, he bought Modernist works and exotic art objects with the fervor of a true believer with deep pockets.

In 1925, the Barnes Gallery, designed by noted architect Paul Cret to showcase Barnes’s growing trove, was built next to his home in quiet, leafy Merion. Inspired by courses with Dewey at Columbia and the philosopher’s theories of experiential education, Barnes expanded his factory programs into the Barnes Foundation, an educational institution dedicated to promoting appreciation for the fine arts and horticulture. His wife Laura developed the arboretum and horticulture program, which continue as integral activities of the foundation today.

Barnes sought to attract working men and women, the poor, young artists and African Americans to foundation programs. His educational method, according to foundation officials, was based on “experiencing original works, participating in class discussions, reading key texts in philosophy and the traditions of art and looking objectively at the use of color, line, light and space in each work of art.”

An irascible, antiestablishment maverick, Barnes went to great lengths to control his institution’s status and activities. Public admission was limited to two days a week, so the facilities and collection would be available primarily for student study, and there were prohibitions against lending works, touring the collection, presenting exhibitions of other art and making color reproductions of works. Matisse is said to have hailed the Barnes as the only sane place in America to view art. It was not until 1961 that these restrictions were eased †public access expanded to 2½ days a week, with a limit of 500 visitors per week and through reservations made at least two weeks in advance.

Among the expanded amenities in the new Barnes is this lower lobby, with modern chairs and tables, looking into the Gallery Garden and Library.

After wrestling for years with questions about eventual disposition of his foundation and the collection, Barnes willed control to Lincoln University, a small, historically black college in Pennsylvania. After he died in a 1951 automobile accident, the foundation struggled with issues about administration of the institution, including financial shortfalls and whether to open the galleries to the public.

Starting around 2000, a consortium of foundations and philanthropists raised funds to move the collection to Philadelphia, where it opened last month with much fanfare on a 4½-acre campus. With the renovated Rodin Museum next door and the Philadelphia Museum of Art just down the street, the 93,000-square-foot Barnes Foundation is now part of the city’s Museum Row †ideally sited to attract the wide general public and further the mission Barnes envisioned.

All the controversy and Barnes’s strange persona, collecting and display methods should not overshadow the magnificent trove he assembled. Today, the foundation owns more than 2,500 objects, including 800 paintings, estimated to be worth around $25 billion. Impressionist and Modernist works predominate, but there is also artwork by other European and American artists, as well as items from other cultures.

The collection includes 181 works by Pierre-August Renoir (the largest Renoir holdings in the world), 69 by Paul Cezanne, 59 by Matisse, 46 by Picasso, 21 by Chaim Soutine, 18 by Henri Rousseau, 16 by Amedeo Modigliani, 11 by Edgar Degas, seven by Vincent van Gogh and six by Georges Seurat. Other leading artists represented are Paul Gauguin, El Greco, Francesco Goya, Edouard Manet, Claude Monet, Peter Paul Rubens and Titian. The few Americans include Charles Demuth, Glackens, Marsden Hartley, Horace Pippin and Maurice Prendergast. There are also varied artworks: African sculpture, Egyptian, Greek and Roman art, American and European furniture, Pennsylvania German decorative arts, Native American ceramics and metalwork.

With the world’s largest holding of paintings by Pierre-Auguste Renoir †181 †Barnes made good on his 1913 declaration, “I am convinced I cannot get too many Renoirs.†Barnes’s Renoir trove includes such masterworks as “The Artist’s Family,†1896.

A notable †and quirky †aspect of the Barnes collection is its display, micromanaged by Barnes in “wall ensembles,” which are purposeful combinations of works from different media, cultures, periods, geographic areas and styles for the purpose of comparison and study. The ensembles, symmetrically arranged, serve to illustrate the aesthetic principles taught in Barnes Foundation art education programs, now greatly expanded. Many of Barnes’s ideas grew out of collaboration with philosopher Dewey.

It is a nearly overwhelming but exhilarating experience to walk through the small galleries, crammed with iconic works juxtaposed with exotic objects or metalwork. But let there be no question: the artwork is amazing, beautiful †and world-class.

Barnes’s two main heroes, Renoir and Cezanne, lead the way. Many of the 181 Renoirs are splendid, such as his charming “The Artist’s Family.” Cezanne, on the other hand, registers strongly with almost all his 69 works †portraits, still lifes, landscapes and a highlight of the collection †the solid, dignified laborers in “The Card Players.”

There are plenty of fine Matisses among the 59, including his angular, colorful “Red Madras Headdress” and “The Music Lesson,” and some memorable early Picassos among the 46, notably a Blue Period star, “The Ascetic,” a signature saltimbanque “Acrobat and Young Harlequin” and a haunting “Head of a Man,” inspired by African masks that intrigued both the Spaniard and Barnes. The 18 Henri Rousseaus tend to be universally compelling, as epitomized by the dreamy “Woman Walking in an Exotic Forest.”

Represented by seven works, van Gogh makes a strong showing, notably with his familiarly hirsute “The Postman (Joseph-Etienne Roulin),” which stands out in spite of being hung in a corner of a crowded gallery. Among the 11 Edgar Degas works is a fine pastel of ballet dancers, “Group of Dancers.” Claude Monet, the French Impressionist leader, weighs in with a beautifully brushed view of his floating workplace, “The Studio Boat.”

Among the six works by George Seurat is his large pointillist masterpiece, “Models,” which at more than 6½ by 8 feet looms over Cezanne’s sizable “Card Players” in the main gallery. Most of the 16 Amedeo Modiglianis make strong statements, including his inscrutable “Redheaded Girl in Evening Dress.”

One has to look hard to spot the Americans scattered around the floor-to-ceiling galleries. There are 70 works by Glackens, who adapted Renoir’s light, bright palette in his mature years, as exemplified by the almost gaudy “Race Track.” Scattered hither and yon are paintings and watercolors by Charles Demuth and Maurice Prendergast.

Among the 33 paintings acquired in Paris for Barnes by his friend William Glackens in 1912 to begin the Barnes Collection is a foundational work, Vincent van Gogh’s broadly painted, compelling “The Postman (Joseph-Etienne Roulin),†1889. One of six portraits van Gogh painted of the mailman he befriended in Arles, this version is notable for the sitter’s steady gaze, carefully delineated, uneven features and the manner in which the artist “turns an ordinary beard into a brilliant ocean of color††black, green, purple, red †in the words of Barnes associate curator Martha Lucy.

At a time when Marsden Hartley was particularly desperate for cash, he sat next to Barnes at a gallery auction when the doctor bought one of the artist’s Bermuda paintings for $100. Later that year, Barnes wrote the artist that he was highly pleased with the effect created in his private office when two of Hartley’s Cubist boat paintings were placed on either side of a Prendergast panel. “Demuth was here when I hung them,” wrote Barnes, “and he agreed with me that outside of a few spots in my house there is probably nothing in America that can touch the wall in sheer, potent, exquisite, meaningful beauty.” Yet Barnes only bought those three 1916 works by the frequently impoverished painter from Maine.

Four paintings by self-taught artist Horace Pippin are fascinating. Barnes championed this African American from West Chester, Penn., who briefly studied at the Barnes Foundation and achieved national fame in the 1940s for his vignettes of World War I and black life.

It is hard to single out the scores of decorative art pieces and small sculptures that are intermingled with so many compelling paintings in the Barnes’ 24 galleries. Numerous chests, particularly those crafted by Pennsylvania Germans, with elaborate motifs, stand out, such as a 1789 chest over drawers.

Less conspicuous are objects Barnes collected during a trip to the Southwest, 1929‱930, such as a Navajo bow guard and Zuni water jar. Seventeen African works are lined up in rigorous symmetry in a case in Room 22, flanked by Modigliani portraits and topped by two resonating, masklike faces by Picasso.

Somehow, in their new, bright quarters, Barnes’s quirky ensembles make more visible his mission “to demonstrate the continuity of artistic tradition and the universal impulse for creative expression,” as chief curator Judith F. Dolkart puts it. At a time when so many museums seem to be dumbing down their exhibitions, the Barnes maintains its focus on quality and contrasts among global artwork.

What once was considered the personal plaything of a colorful, bizarre millionaire art patron, the Barnes collection in its new digs emerges as a major world museum, accessible to all. The Barnes Foundation is well on its way to becoming the towering and influential institution it deserves to be, potentially altering the ways we look at and think about art. Often regarded as a weird rascal, Dr Albert C. Barnes emerges in 2012 as a major public benefactor †and prophet.

Masterworks: The Barnes Foundation , which serves as a museum catalog, is a 374-page, lavishly illustrated examination of Barnes, his foundation, his philosophy of art and education and the new quarters. Written by Dolkart, associate curator Martha Lucy and executive director and president Derek Gillman, it is everything an art lover could ask for as an introduction to the subject. Published by Skira/Rizzoli in association with the Barnes Foundation, it retails for $40.

The Barnes is at 2025 Benjamin Franklin Parkway at 20th Street. For information, www.barnesfoundation.org or 215-278-7000.