The White House task force on the arts and the humanities met for the first time yesterday amid reassurances that its purpose was not to abolish the National Endowments for the Arts and the Humanities.

Early on, task force member Henry Geldzahler, commissioner of the New York City Department of Cultural Affairs, asked if the Reagan administration wanted to dissolve the endowments. Replied actor Charlton Heston, one of the three chairs, "Not in my mind, sir. It is in no way our task to preside over the dissolution of the endowments.

"I think we can provide some useful advice, but I make no promises," said Heston. But he added that the problems facing the task force would not "part like the Red Sea."

The 32 members present, who included such luminaries as Beverly Sills, director of the New York City Opera; Arthur Mitchell, founder of the Dance Theatre of Harlem; John Swearingen, chairman of Standard Oil of Indiana; Librarian of Congress Daniel Boorstin; and Franklin Murphy, chairman of the board of Times Mirror Co., met for over two hours around a conference table in the Indian Treaty Room of the Executive Office Building.

Heston chaired the group along with Hanna Gray, president of the University of Chicago, and Daniel Terra, ambassador-at-large for cultural affairs. The actor said the members should examine the "motivation for corporate giving to the arts and private support . . . ranging from tax incentives to national pride" and "address the structure of the endowments. Our task is not to evaluate individual programs and personnel."

Hanna Gray tried to dispel any notion that the task force would be a rubber stamp for the White House.

"I know from the things people say and from correspondence," said Gray, "that a lot of people wonder if this task force was created to come to a predetermined conclusion. I don't think any of the people sitting here would be sitting here if they felt a conclusion had already been predetermined. It's quite clear from what everyone has been saying that this is going to be a debating society, not an endorsing society."

The main thing the task force -- which was missing four members yesterday -- debated was how they would meet and in what kind of grouping. Most seemed to want to meet each other in direct dialogue rather than be interviewed by staff members who would then report back to the chairs.

If the staff conducts interviews, "you, in effect, become captives of the staff," said Swearingen.

"If I speak to an interviewer," said Nancy Mehta, former vice president of the 400 Group of the Los Angeles Music Center and wife of conductor Zubin Mehta, "how can I hear [reactions]? . . . The ideas I have on [tax incentives] are only one concept. I would love to hear other concepts."

"It's clear that the degree of this body's willingness to fly back and forth across the country," said Heston, "is underestimated."

Frank Hodsoll, deputy to White House chief to staff James Baker, told the task force that "President and Mrs. Reagan . . . personally care about the arts, perhaps more than any other first family. You may aks why the endowments got budget cuts. The administration inherited a bit of an economic mess.

"We have so few places where there are really discretionary funds," said Hodsoll at another point, "and given the extraordinary growth of the endowments, we felt we could do it."

Beverly Sills said she accepted the need to cut, "but I don't accept the fact that money is being cut because it was given to the endowments unwisely. I would like us all to go on the record saying we accept the cuts, not because we're having our wrists slapped." Hodsoll replied that cuts were proposed for "strictly fiscal considerations."

The task force plans to meet again this morning informally in a closed session.