Art meets commerce: at NorthPark, John Newman's Torus Orbicularis,1988; cast and fabricated aluminum with patina; 64 x 52 x 75 in. Photo: Chris Hildreth

Soaring shapes: outside the Nasher Sculpture Center in Dallas, Mark di Suvero's Eviva Amore, 2001; steel; 424 x 564 x 360 in. Photo: Chris Hildreth

For his part, Nasher says the decision was logical: He has spent most of his life in Dallas, his daughters grew up there, and it seemed important to provide a cultural catalyst for downtown development. His catalyzing action, he hopes, will make the city an international art destination. The private Nasher Foundation, headed by Nasher, will maintain the center, decide what will be displayed, lend pieces not on display to other museums, and buy new works.

If the Nashers didn't create a new awareness of sculpture, they fed that awareness. "There's a famous, rather snide quote from an abstract artist of the New York School," Steven Nash says. "He said that sculpture is what you bump into when you're backing up looking at paintings. But there has been a growing recognition of sculpture. I think part of it is just more exposure--more sculpture gardens, more cities with public sculpture. But it also is a market condition: As paintings become rarer and increasingly expensive, sculpture by the same artist, which is of equal quality, becomes more and more attractive."

Harry S. Parker III, now director of the Fine Arts Museums of San Francisco and formerly director of the Dallas Museum, says, "One of Ray's qualities is that he likes the big idea, the big vision. I think from the very beginning, he saw an opportunity to create a big idea, which was a comprehensive, high-quality collection of modern sculpture. When Ray started it, it was something pretty darn new. Ray worries over the details, he worries over getting everything right. But the big concept is what he goes for."

To Nasher, sculpture is simply more interesting than painting, both as a creative process and for the impact on the observer. "Sculpture has dimension, which is vital and which makes it much more interesting than painting," he says. "You put a painting on the wall, and you get the illusion of depth. But my feeling is that a piece of sculpture is really 360 different works: Every one of those 360 degrees gives you a different sense of the sculpture.

"When you have a piece of sculpture outside, it's basically a living element. You have to wax it, you have to wash it, you have to conserve it. With a painting, you might have a work in oil or watercolor. But we have something like thirty-nine different materials in our collection. The artist can put his hands on that clay, on that terra-cotta, marble, wood, or whatever he's using. He can really dig into it, he can really feel it."

Just three years ago, Nasher reached back to what he considers the starting point of modern sculpture, acquiring an 1876 plaster casting of Auguste Rodin's The Age of Bronze. The youth's right leg is bent at the knee, his right hand grips his head, his eyes are closed in concentration, and his mouth is slightly open, as if he's about to speak. A curatorial friend had called Nasher to say that it had just become available on the market; the work had been in the collection of the foundry that had originally cast the plaster into bronze. Since Rodin, Nasher says, "more has happened, from a sculptural point of view, than happened from the beginning of history. From the time of Michelangelo and the Renaissance until Rodin created the figurative age in bronze, there was a vacuum in sculpture."

In Nasher's house, the Rodin now shares a gallery otherwise devoted to Alberto Giacometti. In works like the three busts of his brother Diego, Giacometti's forms are an enigmatic, amusing, and unsettling coupling of the figurative and the abstract. Parker recalls the Nashers newly displaying "those tiny, terribly, terribly fragile Giacometti sculptures that, I guess, would fit in a matchbox. I just remember thinking that it would take a well-educated eye to see them for what they were. But they were some of the most exquisite sculptures that Giacometti ever did."

The Giacomettis seem purposively primitive. Distinctions between the modern and the primitive can disappear in sculpture, Nasher observes. That point is illustrated just outside the front door, with Reclining Figure: Angles, a bronze by Henry Moore. Moore's works show a fascination with natural forms, along with the classical and the primeval; they carry suggestions of landscapes, rock formations, bones, and the human figure. In 1967, the Nashers traveled to London for the Wimbledon tournament and visited Moore in Much Hadham. Sheep strolled about, and pieces of sculpture were strewn about, the pasture area that surrounded Moore's studio. At the time, Moore was working on Two Piece Reclining Figure No. 9. He also showed the couple three stones that would become the basis for Three Piece No. 3: Vertebrae. The next year, Moore told the Nashers that he had finished both pieces, that they were at London's Tate Gallery in a retrospective, and that the couple might want to come over and choose one. They ended up buying both.

Moore, as a houseguest of the Nashers, became enamored of one of their Oceanic pieces. He ended up doing a lithograph based on the piece, which he gave to the Nashers. Later he turned the composition into his own sculpture, one of his reclining figures.

The Nasher Collection doesn't just juxtapose the modern and the primitive. It also sparks a conversation between works of art, and even between art and life. A gaze into his living room takes in a wall displaying a Picasso painting, Vase of Flowers on a Table (Bouquet), an exuberant composition in gray, green, blue, red, and yellow, seemingly about to burst out its frame. A Picasso sculpture, Flowers in a Vase, made of plaster, terra cotta, and iron, rests on the living-room ledge. Then a real bouquet of flowers occupies a table. David Smith's The Forest, made of steel painted green and pink on a wood base, is alongside the living-room windows, which look out on the forested grounds.

Having so much sculpture to place gives a collector the license to act as "a lay artist," in Nasher's words. The collector creates a composition--incorporating factors of light, shadow, and relationship--as he arranges the works. "You can place sculptures in a thousand different ways," he says. "But being able to have them talk to each other, to have them relate to each other meaningfully--that makes a tremendous difference in the quality of the exhibition."

In the house's library, Nasher is surrounded by sculpture and by his sprawling collection of books, which was organized by a professional librarian. The largest category is, unsurprisingly, "Art." Sitting at an Art Deco table, under a painted, sheet-metal mobile by Alexander Calder, he points to a small Mask: Reclining Head by Julio Gonzalez, circa 1930. "This Gonzalez, on the table, is truly one of the very, very important pieces of the twentieth century. Gonzalez was the first one who was able to take a welding torch to iron and make significant pieces out of it."

He turns to a Max Ernst bronze from 1944, The King Playing with the Queen. "These two are of different materials, they're of different sizes, and the Ernst head, unlike the Gonzalez mask, is done surrealistically. But there's a relationship between them."

Visible through the picture windows is Barbara Hepworth's Squares with Two Circles (Monolith), one of the first fully abstract works in the collection. The Nashers came across the sculpture in front of the Tate Gallery; Hepworth later agreed to sell the work to the Nashers and lend another piece to the Tate. While it has the purity of a study in geometry, Squares with Two Circles seems well integrated with its natural surroundings. Slender and more than ten feet high, with a bronze surface fading into green, it mimics the trees around it, even as the viewer's gaze takes in those trees through the sculpture's "empty space." Nearby is a George Segal cluster of commuters, Rush Hour; Duchamp-Villon's Large Horse; a Picasso Head of a Woman; and Richard Serra's four-piece Inverted House of Cards. Nasher calls the Serra, a solid and severe work in which steel plates fold in on each other, "minimal and rusty and a little dangerous." He and Patsy, as he once put it, "didn't want just polite works around us."

Still, sensuous, figurative works are prominent in the collection. Constantin Brancusi's 1907-08 plaster work The Kiss--embracing lovers with anonymous, abstract, primeval features--is an intensely sensual response to Rodin's sculpture of the same name. It sits on the Nashers' dining-room table. Matisse reclining figures and other Matisses populate the living room; the collection includes the largest group of Matisse sculptures in private hands. "We loved his paintings, but we couldn't afford them," Nasher says. "His sculptures weren't considered that important. But from our point of view, they were more exciting than the paintings. And they were about a tenth of the price."

The couple's first Matisse was Large Seated Nude, purchased in 1983. It was more than twice the price of anything they had bought before. Nasher calls it one of "the great pieces of all time." Because there was so much interest in it, they had to make a same-day decision. Nasher has said that the Matisse purchase "gave us the freedom and confidence to seek only the very best."

Over the years, that self-assuredness has been bolstered by a relentless drive to learn about, and to seek out, the best. Parker, the San Francisco museum director, pauses when asked if he's ever encountered a collector as exuberant as Nasher. "Exuberant is a good word. But you can't ignore the fact that he really works hard to find the very exceptional pieces. He is as single-minded as anybody I've ever met. Even with a general category like David Smith sculpture, you have to ferret out the really unique pieces--the rarest and the highest-quality pieces. It's not just the enthusiasm he has for collecting. It's also his intellectual rigor."

Parker moved to Dallas in 1974 and bought a house two doors down from the Nashers. He and his family would make use of the Nasher swimming pool, splashing in the vicinity of sculptures like Joan MirÛ's Caress of a Bird, a painted bronze over ten feet tall that suggests, among the bird's features, an ironing board, straw hat, and carrot.

Parker recalls a visit in the mid-Eighties to the Nasher house by Picasso's widow, Jacqueline. Walking over to Picasso's The Studio, from 1961-62, she recognized the painted representations of her household's sofa and blanket. And she was moved to tears by Picasso's 1971 Man and Woman. In the painting, Picasso is more recognizable than his cubistically rendered companion--at the time, Jacqueline, of course. He presents himself as old, grizzled, and nude, with a face resembling an exaggerated skull or mask. Jacqueline saw in the painting a premonition on Picasso's part of his own impending death, which would come two years after the canvas was painted.

" She had seen the painting, but she hadn't seen in it a long time," Parker says. "She was also very taken by Ray's passion and enthusiasm. I think she saw some of the same qualities in him that she loved so much in Picasso himself--a very direct, aggressive, and passionate personality."