"I believe that all of us in the Business Commitee for the Arts," said its chairman, Rawleigh Warner, "must do everything we can to convince people that the federal cuts [in the National Endowment for the Arts budget] do not signal the demise of Western civilization."

Those were not exactly new words, but they were key ones from the man who is also chairman of the board of Mobil and was speaking to a roomful of representatives of such corporations as American Telephone and Telegraph, Exxon and United Technologies, to name a few.

The occasion was the annual business meeting of the BCA, a group of 146 companies that promotes corporate support of the arts through information conferences and relays statistical data supporting the arts.

And although large corporations have testified before both houses of Congress that corporations will not be able to pick up the slack left by massive cuts in the National Endowment for the Arts, BCA officials spoke optimistically at the National Gallery of Art last night about how corporate support could be increased.

"We shall all have to do a great deal of selling the corporate sector on philanthropy in the arts," Warner told the audience of about 200. More than half the group's members were present, one BCA official estimated. Warner noted that about 70 percent of the 2 million corporations in the United States do not report any charitable contributions.

"We put on eight to 10 conferences a year to talk to businesses," said Edward Strauss, president of the BCA, after the meeting and before dinner in the gallery. "We may have to put on more. We'll have to encourage more local business committees . . .We're selling an idea. We're like Billy Graham. We're out preaching the gospel. It's absolutely essential that businesses support the arts."

One member of the BCA was disappointed that the committee didn't do more selling to its own members. "I wanted them to tell us how [to get corporations to support the arts]," the member said.

Warner -- whose Mobil Corp. recently sponsored an ad optimistically stating that business and individual donors had been doing most of the giving to the arts and could do a lot more -- admitted that business could not take up the slack created by the cutbacks to the National Endowment for the Arts. "The BCA has to invigorate the business community to get more involved," he said. "It's a process that feeds itself."

Said Harry Gray, chairman of United Technologies: "That'll take a massive education program. That 70 percent is a lot of small businesses. They don't think in terms of supporting the arts. They think in terms of making it through the year, making a profit and planning for next year. But they can do it. You have to think in terms of small increments. Even if you could get them to contribute $1,000, that's a lot. I don't think you can completely fill the gap, but we can step in.