Four secretaries of State, past and present, got together Wednesday night for the first time anyone remembered.

On the historic occasion at the State Department's Diplomatic Reception Rooms, they swapped advice on how to save the world. They agreed that Clement Conger has done a good job remodeling the entertaining rooms And the three former secretaries said they all though Cyrus Vance, the current secretary and their host, should be commended for his "integrity dedication and professionalism." They also said he had their sympathy.

The event was a $1,000-a-plate dinner that raised $200,000 for further remodeling of the rooms to serve as a setting for the collection of American antiques and portraits and the secretary's official entertaining.

Dean Rusk in his speech paid tribute to Benjamin Franklin, for whom one of the rooms is named. "He was the first secretary of State and the first CIA agent. He made a lot of payments in France that Congress wouldn't reimburse him for, and he didn't even write a book."

Before the dinner, while people ate quail eggs and miniature smoked-ham sandwiches, everyone collared the former secretaries for their opinions on SALT, the Cuban troop crisis, the defense budget and the state of the world in general.

Dean Rusk, now a professor at the University of Georgia, said the Cuban crisis worried him because he was afraid that "children are playing with dynamite."

Rusk said he thought the Russian troops had been in Cuba for a long time. "There's no point in trying to revive the Cuban missile crisis," he said. "It's a campaign year. I think the politicians are reaching for arguments."

Rusk went on to say that if he were a senator he would vote for SALT: "It has a good balance."

Henry Kissinger said he was very much concerned about the Cuban affair. "It's not just the Russian troops in Cuba that bothers me. It's also the Cuban troops in Africa. It's the totality."

Vance, on his part, said he often called his predecessors for advice. "And they call me as well."

After the dinner, which was based on former secretaries of State's recipes, including rock fish and roast pheasant, with a sorbet in between, all four spoke formally, introduced by the evening's chairman, Leonard Marks.

Vance said he was very happy to find that not only had his predecessors survived, but that they were all in good health and humor. He noted that Dean Rusk had named five of the rooms for secretaries of State who became president. And he suggested that if the Constitution were changed (to allow a foreign-born citizen to become president), they could add a sixth room. Later, Kissinger said they didn't have to wait on constitutional amendment, they could begin the room now.

Rusk said it had been 135 years since a secretary of State had become president. "They might as well have the motto over the door, 'Abandon hope, all ye who enter here.'"

Presidents hold the secretary responsible, Rusk said, "for all those funny foreigners who won't do what we want them to do. Some presidents don't like it more than others. People are always pointing the finger and saying, 'You lost us China . . . Cuba . . . Iran' -- as though they were ours to lose."

He said that all secretaries of State try to save some problem for their successors. "When I turned the department over to Secretary Rogers, I told him here are seven decisions you must make in 24 hours. He said, 'Don't you want your job back?' Some of those problems are still with us. Secretary Vance has quite a few. The roots of some go back to Theodore Roosevelt, and some to Moses and the creation of oceans."

Rogers said that secretaries of State come and go, but Conger "goes on forever. There's been a recent rumor that he might be secretary of State. He did say he'd talked to his wife and children." Rogers described Conger as "a peripatetic tax shelter. When I first came into office, I gave him a gift for the reception rooms and he congratulated me on the 'many more opportunities you'll have to give.'

"I said we'd give what we could in our lifetime. And he said, 'Death doesn't relieve you of the necessity of giving. Now I have a short-form will here, you don't even need an executor. Just leave everything to the State Department Americana fund and include my toll-free number for any questions.'"

Rogers noted that Chief Justice Warren Burger was at the dinner and had tried to borrow some of the antiques for the Supreme Court project. "I never loaned him anything for his 'Son of Clem' collection."

Rogers said he agreed that everything in the world is blamed on the U.S. "One morning when I was being briefed on the world happenings. the officer told me that there was no good news. But there was one piece of bad news that couldn't be blamed on us -- the Aswan Dam was leaking."

Kissinger said he had been practicing his speech in front of a mirror, but "all this distinction I see before me doesn't match that thrill."

Conger said the money raised last night from the 165 black-tie, evening gown guests (some gave more than the $1,000 asked) will go to remodel the men's and women's anterooms to the lounges, at a cost of about $250,000. After that, he hopes to add paneling and other elaborate woodwork to the secretary's office and reception room.

"And after that . . . . "