A politician from English-speaking Canada was wondering aloud the other day about the extraordinary nature of the debate over predominantly French-speaking Quebec's threat to secede.

English Canada, said Flora McDonald, a Conservative Party deputy from Ontario, may be "getting tired" of watching two French Canadians "deciding the future of the country."

The two are Prime Minister Pierre Trudeau and Quebec Premier Rene Levesque. Both are from Quebec. But while Trudeau is fervently committed to Canada's unity, Levesque is just as passionately trying to gain political independence for his province.

There is a feeling among the "Anglos," as the English-speaking Canadians are called, that they have by default let the "Francos," or the French-speaking minority, dominate a debate that is crucial to Canada's future.

There is some talk here about the possibility of an "English backlash." Some commentators have adopted a hostile tone on the debate on national unity which may ultimately influence the country's survival.

Yet Canadians seem as mesmerized by the two Quebecois as they are perplexed by the absence of political charisma and talent among Anglo politicians.

There is a peculiarly French slant to it all, as the chief protagonists debate the issue on live television. (Simultaneous English translation is available.) It is a personalized showdown with shrill rhetoric and martial pledges of ultimate victory on both sides.

Trudeau, who portrays himself as the preeminent nation-saver, argues the federalist case uncompromisingly Levesque sees no possible future for five million Quebec Francos short of establishing a new, independent French-speaking country in North America.

The best available assessments now suggest that a vote on independence in Quebec would be close, and that the outcome would depend largely on the kind of price backers of Canadian unity would place on a new French-speaking nation's ties with the rest of Canada. The price probably will not become clear until shortly before the independence plebiscite, which is to be held next year.

In the interim, Canada will continue drifting as it has ever since Leveque's Parti Quebecois came to power in the province in November 1976.

The possibility that Quebec residents may vote in favor of an independent state poses a number of problems. To begin with, Canada would be practically torn apart, with the tour Maritime provinces east of Quebec cut off from the rest of the country.

Defense, transportation and economic dislocations could be monumental. Above all, the weak spirit of Canadian unity may be damaged in English provinces which might seek some form of association with the United States.

These alarming aspects are somewhat offset by what students of Canadian affairs see as the traditional inclination of Canadians to avoid drastic actions. The Canadians, in this view, don't seek resolutions of problems; they cope with them and pass them on to their children.

In the shrill tone of Trudeau-Levesque confrontations, the nature of Quebec separatist ambitions has been deliberately obscured by both sides. Trudeau charges that Levesque wants to "break up the country." Levesque argues that all he wants is political "sovereignity" for Quebec, which would remain in an economic association with the rest of Canada.

Underlying these arguments is the question of safeguarding the French culture and heritage for nearly six million Francos.

In his "little red book" entitled "Ouotations from Rene Levesque," the Quebec separatist leader sees independence for the province as inevitable. What concerns him is "how are we going to go about it? By violence or by democratic action?

"I hope we get there the civilized way," he says.

Levesque's "foreign minister," Claude Morin, outlined the separatist strategy in broad terms during an interview here recently. The crucial problem, in his view, is that two strong cultures - in this case, the English and the French - can not coexist in a single state.

Beginning with that premise, Morin sees the need for a sovereign Quebec in association with Canada. Several types of economic association are considered, among them a free trade area, a customs union, a common market and a monetary union. Each involves a progressively greater degree of economic integration.

Morin would not disclose what type of association is comtemplated - or what type of political relationship between Quebec and the rest of Canada would be appropriate for various options.

The Francos community of Quebec is by no means united on the issue. The French, who first settled the province, have seen themselves as a subjugated people ever since the British wrested control of Quebec from France in the 1759 battle at the Plains of Abraham.

Ever since, the most rural and Roman Catholic Quebecois have lived a life separate from the English-speaking community. Industrialization and the advent of modern communications during the past two decades have changed the nature of Quebec society and the peculair type of isolation in which the Francos have preserved their heritage.

As a result, French nationalists believe that without independence, they may well eventually drown in the English-speaking vastness of North America.

There is a sizable portion of Quebec opinion, however, that supports Trudeau's concept of a tolerat, bilingual Canada as the best way of ensuring the survival of French culture in North America.

But Trudeau's appeal is intellectual and reasoned. Levesque's is directed at gut instincts.

Moreover, Trudeau is not longer the refreshingly engaging and unconventional politician who became Prime Minister in 1968. Canadians are wary of him now. Over the past 10 years, they have heard many Trudeau declarations - the "Just Society," the "Third Option," the "New Partnership."

The source of his strength, especially in the English-speaking community (which comprises 16 million of Canada's 22 million population), is his image as a man who can save the country. This image is carefully cultivated. One of his week that "it is very important and very beneficial that the prime minister is a Quebecois."

"If it were otherwise," he added, the people could see the current national unity debate "as a French-English struggle.

But by focusing on the Quebec question, Trudeau forces tend to disregard the growning trend toward regionalism. Canada is a collection of loosely linked provincial societies and economics. The mood in the country is one of the alienation from Ottawa, a feeling that the federal government does not really represent regional interests.

The regional premiers have become more assertive over the past decades. While state governments in the United States have gradually abandoned powers to the federal government, the reverse is true in Canada. Powerful regional barons, such as Peter Longheed of Alberta, now turn down offers of national posts to keep their provincial power base.

What Levesque and his Quebec separatists have done - and even their opponents give them credit for this - is to confront the country with its failure to develop a national self-image.

Canada does not have a George Washington, a Thomas Jefferson or an Abraham Lincoln. The past heroes for the Anglos are viewed as enemies by the Francos. The most popular play in Quebec these days deals with a French rebellion against the British in 1837.

For unknown reasons, Canadians have had difficulties in developing a common vision of the future. Thus the Quebec question may help shape a debate over where this country is heading.