A sign at the Philadelphia Airport greeted Vice President George Bush on his arrival. It said: "Bush KOs Ferraro." It was the last thing in the world that the gentlemanly vice president wanted to do. Even if it were not against his code, he knew it would be fatal for him to be beastly to history's first woman vice presidential candidate.

What was unexpected in the bare hall of the Civic Center under the bright lights was the discovery that the usually combative Geraldine Ferraro also did not have a knockout, or even a good fight, in mind.

What was clear from the beginning was that while Bush was out, as usual, to please the boss, Ferraro felt her business was with the American public. She wanted to show that she can speak slow, speak low and be a lady at all costs.

Their encounter, which was originally expected to be a kind of "all in the family" type showdown between Queens and Kennebunkport, between those who inherit their money and those who earn it, between Ivy League and night law school, was a strangely muted affair.

Ferraro knew from the exceptionally robust language emanating from the Bush dugout chatter that she was being goaded to come on as strident and, in the word of Bush press secretary Pete Teeley, "bitchy" -- an echo of something Bush's wife, Barbara, had surprisingly said, and retracted, earlier in the week.

She was hardly recognizable as the confrontational, "lemme-tell- ya" self of the stump, the campaigner who tamed a bucking bronco of a Texas University crowd and the tough challenger of blue collars who had the nerve to think of voting for Ronald Reagan.

She was wary and programmed.

"She was so toned down," said one middle-aged woman partisan, "I was disappointed. I like her better when she speaks up."

Bush was at his most maniacally sycophantic. He waved his arms and raised his voice. He flailed away at the "despair and malaise" displayed by Walter Mondale, a man with his head in "dark clouds." At the end of one recklessly upbeat statement about the Reagan civil rights record, he said, "I mean right on, whine on, harvest moon."

He was out to defend Ronald Reagan and he did a better job of it than Reagan had done Sunday night and said many of the things that Reagan forgot to mention in the feeblest appearance of his political career.

Ferraro, her manner matched by her neutral brown suit, ignored him as much as she could. The talk turned to foreign policy where she feels the weight of his thick portfolio most heavily. The subject was Lebanon, and he accused her of saying that the Marine casualties of terrorist bombing had "died in shame."

Ferraro turned on him with the first show of her wonted spirit. She was being patted on the head, and she reacted with a flash of temper.

"I almost resent the vice president patronizing me," she retorted. "Please don't categorize my answers -- leave that interpretation to the American public. No one would say that about the loss of anyone else's son. No one with a child would ever say that about the loss of anyone else's child." Her response made credible the answer she later gave about how a mere woman would deal with Soviet provocation, should force be needed. Her response, she said, would be "swift, precise and certain retaliation."

Ferraro accused the administration of being "befuddled" in its Nicaraguan policy. Bush accused her of wanting to do away with all covert activity by the CIA.

He spoke fondly of the contras as friends of democracy and defended the mining of the Nicaraguan harbors. She spoke to a larger audience and said that she was opposed to the covert war and pointed out to him that a majority of people in the country agreed with her.

She let him get away with his account of traveling to Geneva to present a chemical warfare treaty to the Soviets. She did not mention that he had cast the tie- breaking vote in the Senate to promote a U.S. buildup of chemical weaponry.

Ferraro was speaking to the 50 million American living rooms; Bush was talking to the Oval Office. She was trying to show that she could play in the majors; he was content to demonstrate that he is one of the boys.

When he was asked at the end what single question he would have liked to ask his opponent, he said, "I would just like to use the time talking about the World Series, or something of that nature . . . ."

In his closing statement, Bush reeled off a segment of his standard campaign pitch, extolling the glories of the Reagan administration as the reversal of "the vacillation and weakness and failed policies of the Carter- Mondale years."

Ferraro spoke of stopping the arms race and of Mondale's efforts in behalf of the unrepresented, the migrant workers, defenseless defendants and voiceless children.

She concluded on a defiant note, more plausible since Mondale had asserted his place as the head of the ticket in Louisville: "This campaign is not over . . . . Walter Mondale and I have just begun to fight."

Afterward, the opposing managers gave the verdict: Reagan's political director, Edward J. Rollins, said disparagingly, "She proved she's a great congressional candidate in a Democratic district."

Ferraro's press secretary, Francis O'Brien, said quietly, "She did just what she had to do."