Dr. Joshua C. Taylor, 63, director of the Smithsonian's National Museum of American Art and a preeminent American art scholar, died at Georgetown University Hospital Sunday following as heart attack.

Dr. Taylor was well known not only for his scholarship but for his zest for teaching others about art. He came to the then National Collection of Fine Arts in January 1970 from the University of Chicago, where he was thought of as a teacher who "set students on fire with love of learning."

He came to the museum, he once said, with the idea of "putting some of the energy I had spent on lecturing into writing."

"A museum," he wrote, "is not a graveyard of remembered feelings, but a source for new experience . . . ." The viewer, he said should "question himself, not the expert."

He wrote introductions and many essays to the several hundred exhibits organized in his 11 1/2 years at the museum. Harry Lowe, the museum's assistant director, said, "He took pride in the fact that our museum considerably slowed down students who came to work on their degrees. They learned to go much deeper in their subject. He was impatient with students who were too narrowly specialized and wouldn't go five years out of the period they were studying.

"He had no patience with teaching art from slides. He thought there was no substitute for looking at the actual object." In the children's room at the museum, he had sculptures that children were encouraged to touch. He painted walls vivid colors as backgrounds for paintings. "White backgrounds make people think they're seeing the painting in a book," he said.

Dr. Taylor presided over the opening of the Renwick Gallery (a department of the National Collection) in 1972.At that time he said of the Second Empire style structure in which it is housed: "The extraordinary atmosphere of the building itself makes the museum's principal point: design is not an isolated element but affects all that we do." He said that the purpose of the gallery is "pleasure through discovery -- to introduce you to an awareness of things you might not notice."

During her years in the Vice President's Residence, Joan Mondale, an art historian and writer herself, organized four important collections of art from American museums to hang in the house. She said yesterday, "Dr. Taylor offered to have his staff receive the loans and hang them in our house. Museum directors were more willing to lend art because of him. More than that, he was a charming man and a great scholar."

Taste for Dr. Taylor was a wide concept.He once said, "I never trust an art historian who doesn't like to eat. When I took students on a graduate seminar in Rome, I always gave them lists of restaurants first -- I thought they'd find the museums on their own.

"Art is a sensuous experience. When you look at a painting you should have the kind of thrill the artist had when he painted it. It is important to accept art as part of experience.

"Most art history jargon drives me up the wall. I tell my students to look for the texture of history, the unusual relationship. The imbalance between things you don't expect."

His former students, now scattered in important positions through the country as museum directors, art critics and so on, remembered dinners at his apartment in Chicago, where he would hold forth at the stove as well as in conversation.

Often, at the National Art Museum, he'd welcome art scholars over lunch in his office -- served on an antique mahogany table, covered with a fine cloth, cooked and served with appropriate elegance. Not long ago, Dr. Taylor arranged an especially elegant dinner at Barney Studio House, a museum filled with paintings by Alice Pike Barney, a Washington grande dame of the early part of the century. He had recently restored the house to her period, taking the most meticulous interest in everything from the curtains to the Tiffany candlesticks.

Dr. Taylor lived in a Georgetown townhouse, selected for its garden views. But he enjoyed his position as the "patron" in Taxco, Mexico, where he owned a house for many years and was important in preserving the old town's historic district. He was virtually bilingual in English and Spanish and also spoke excellent Italian, German and Dutch.

Dr. Taylor, who was born in Hillsboro, Ore., studied at the Museum Art School in Portland and designed for theater and ballet during the mid-1930s. After finishing his bachelor's degree at Reed College, he taught theater there from 1939 to 1941.

During World War II, he entered the Army as a private and rose to major, earning a Bronze Star along the way. Part of his Army service was in Italy, and it was then that he decided on art history as a career. After the war, he took a master's degree in literature at Reed and then went to Princetown, where he earned master's and doctorate degrees at Princeton University. He taught there part time.

In 1949, Dr. Taylor began teaching art history and humanities at the University of Chicago. He won the Quantrell Award for excellence in undergraduate teaching. He became the William Rainey Harper professor of humanities in 1963. Dr. Taylor kept his affiliation with Chicago until 1974, flying back to teach and guide student theses.

Under Dr. Taylor, the National Collection of Fine Arts became a center for graduate and post-graduate American art research as well as education programs for children and the public. Under his guidance, the museum has produced about 25 exhibitions a year.

His books include "Learning to Look" (1957; 1981) and "William Page, the American Titian" (1957), both published by the University of Chicago Press; "Futurism" (1961) and "The Graphic Works of Umberto Bocioni" (1961) for the Museum of Modern Art; "Vedere Prima di Credere" (1970), published by Nuova Italia; "To See Is to Think: Looking at American Art" and "American as Art," published by the Smithsonian Press, (1979), published by the University of Chicago Press.

Dr. Taylor was a board member of the Museum of Contemporary Art of Chicago, the American Federation of the Arts and the National Humanities Faculty. He was a member of the advisory committee on 20th Century art of the Art Institute of Chicago and a member of the Faculty Advisory Committee of the Encyclopedia Britannica. Until his death, he was president of the College Art Association and a member of the Advisory Committee of the Archives of American Art, the Association of Art Museum Directors, the American Association of Museums and the International Institute for Conservation of Historic and Artistic Works. He was a Benjamin Franklin Fellow of the Royal Society of Arts.

He leaves his two sisters, Mrs. Stanley Johnson of Portland, and Mrs. William Wuorinen of Salem, Ore.