The theme of the losers' revenge is a natural one for French Canadians, who have played it often in their history of conflict with crown and country. The other evening, after the repast at Mme. Demers' museum-like Restaurant L'Atre on the Ile d'Oleans had ended with a dish of the luscious island strawberries and clotted cream, and the cognac was being passed, the latest chapter of the continuing story was told.

It seems that after the Separatists lost the referendum for a mandate to negotiate "sovereignty-association" with English-speaking Canada, the government of Quebec Premier Rene Levesque discovered a pressing need for the office in the capital that had been occupied by the lieutenant-governor, the queen's representative in the restless province.

The gentleman's cries of protest and expressions of indignation were all to no avail. He was moved unceremoniously to a nearby building and the Separatists celebrated their conquest of the queen's dominion with a party on his premises that could not have been more boisterous if the victory had been real.

It takes such talent to remain tolerably sane in the world of politics, which hands out many more defeats and frustrations than triumphs to those who choose to gamble on its caprice.

In this respect, American politics has perhaps outstripped all others in providing balm for the wounds of its losers. We have institutionalized the consolation prize in the office of the vice president, and have used it, almost invariably, to give a measure of revenge to those who have been abused by the fates.

Thinking back to the first political convention I covered, the Democratic gathering in Chicago in 1956, Adlai Stevenson threw open the No. 2 place to the choice of the delegates. Estes Kefauver, who had struggled through the primaries in both 1952 and 1956 only to lose out to Stevenson, was given the reward of losing with Stevenson.

In 1960, there were a double playoff. John Kennedy rewarded Lyndon Johnson, who had fought him to the end -- even providing a foil for Kennedy's witticisms in a convention-week debate. And Richard Nixon made amends to Henry Cabot Lodge, who was not only the victim in 1952 of Kennedy's ambitions for the Senate, but in that same year was passed over for vice president when Dwight D. Eisenhower picked Nixon as his partner.

In 1964, it was Johnson's turn to provide solace for another of Kennedy's political victims, Hubert H. Humphrey. And in 1968, Nixon showed his profound understanding of the role of the vice presidency by using it to reward Spiro Agnew, a man who felt himself betrayed by the on-again/off-again waverings of his personal hero -- and Nixon's great rival -- Nelson Rockefeller.

In 1972, George McGovern seemed uncertain what he was doing with the No. 2 spot -- as he was about many other matters. His bid to Sen. Thomas Eagleston was a breach in tradition, since it did not cure political embarrassment but caused one. After Eagleton's departure, however, McGovern shopped the job among a whole crew of Democratic losers before finally finding a ready recipient in Sargent Shriver, the much put-upon and put-down brother-in-law of the Kennedys.

In 1974, Gerald Ford used the vice presidency well to reward Rockefeller for his 14 years of humiliation in the Republican Party. But, unconscionably, he snatched the prize from Rockefeller only two years later -- a decision that he publicly acknowledged he later came to regret.

Who can doubt that the gods, seeing this folly on Ford's part, decided to tempt him with the vice presidency earlier this month, before putting it out of his reach on the grounds that his demands were too greedy? Ronald Reagan then gave it to the proper person, the biggest loser in the 1980 primaries, George Bush, who had earned it by learning that his biggest victory -- in Michigan -- was fatal to his chances of success.

That brings us to the Democrats in Madison Square Garden. Four years ago, Jimmy Carter did the right thing by picking Fritz Mondale, who had talked himself out of contention before the first primary. But this year, Mondale has no wounds that need to be healed. The consolation prize properly belongs to Ted Kennedy, which would also neatly close the 20-year cycle.

How Carter rids himself of Mondale and sets the stage for giving Kennedy solace is not a question I am prepared to answer at the moment. But I'm going to have one more helping of strawberries, and then head north into the woods. I will be back in a week -- and maybe we'll have an answer.