The artist wants you to touch his sculpture.

Yes, touch. Yes, his sculpture. That is against your nature, against the hands-off, "noli me tangere" order of the visual universe, typical in galleries and museums, where paintings and sculptures and mixed media are perceived -- and, consequently, interpreted -- through the eyes.

You do not touch. That's the rule.

But the sculpture is inviting. It curves, swirls; at one moment smooth, in an instant jagged. Call it conflict.

"It's the masculine versus the feminine," the artist explains. "Can you feel it?"

Luis Passalacqua is blind. Fingers serve as eyes. Texture replaces color. So his sculpture, "Transfiguracion" -- in blondish-red cedar, nearly four feet tall, and 20 inches wide -- is meant to be felt, the viewer integrated into the art itself.

The sculpture at Union Station flirts with reflection, with a sphere -- an oversize baseball, really -- sitting at the top, roosting on a slide that thickens and thins throughout, all of it resting on three knobby legs. An audio guide to the exhibit calls it "a kind of surreal waterslide."

That sphere, to Passalacqua, is the "potential" -- the hope in achieving balance, "both the yin and the yang," he says, in life and in art.

This is perhaps too broad, too abstract, for Chelsea Starin and R.J. Porter to understand. Chelsea, after all, is 11, R.J. only 6. And besides, they are very familiar with the rule. This is all very new.

Chelsea closes her eyes. "It feels," says the girl from Eau Claire, Wis., in town with Girl Scout Troop 327, "like, like a roller coaster."

Not so to R.J., of Northeast Washington. "It feels alive," he says. He sips his soda. "But it looks like a girl, or a boy, or . . . I don't know."

Passalacqua, 48, smiles through this, the way a teacher would smile at his students.

"Feel it," he urges. "Go on." He is a patient man. Questions arise: You're blind, how can you sculpt? You're blind, how can you tell the time? He follows your voice, faces you, and replies, "I sculpt carefully," and "My watch talks."

He flew here from San Juan, Puerto Rico, for the 30th anniversary of VSA arts, an international nonprofit group that promotes education in the arts for people with disabilities. Some 16 artists, from all over the world, have agreed to show their work in tactile tours in Union Station and the Kennedy Center; viewers, some of them tourists, some of them family members and friends of the 300 artists in town for the festival, have come to see the works -- paintings, installations and mixed media.

Deborah Costandine, diagnosed with depression for some 20 years, stands in front of "Spiked Heels." She drove from St. Paul, Minn., to be here, "honored," she says, "just to participate." Her work circles around "the idea that in life, pain and beauty are often juxtaposed." The hot pink shoes, their insides with 13 parallel rows of quarter-inch silver metal spikes, is a metaphor.

"Touch it," says Costandine, 47. "It's painful and beautiful -- that's what life is all about, isn't it?"

Passalacqua agrees, to a point. The painful part began during Christmas 1995; meningitis cost him his eyesight. He was a medical illustrator then, had his own business in Texas that specialized in orthopedics. The following year, he says, was "one full of denial, anger, depression. . . . I didn't know what to do with myself."

Then, during an afternoon shower at his mother's house in Guaynabo, Puerto Rico, he remembers praying, "O, Dios, no encuentro el camino en la oscuridad." ("Oh, Lord, I can't find my way in the dark.")

He had been an artist all along. But what's an artist to do without his eyes? He felt paralyzed. How could he judge himself? How would he compare his work to others?

This can't be so, Passalacqua told himself. It cannot be all about seeing.

"I realize that man's imagination has no limits. If you describe something -- not just the way it looks but the way it feels -- then it's a thousand times more beautiful. You make it yours. Touching it makes it yours. Barriers go down. You're not afraid of trying something just because your eyes tell you to be careful, that you're going to ruin it.

"You become free."

The exhibition, with live audio description, continues at Union Station today at 3 p.m. and tomorrow at 11 a.m. and 2 p.m.