Of all the many distortions of historical fact used to justify the Meech Lake Accord, the worst is the suggestion that somehow it had all been promised before by Pierre Trudeau.

Usually this takes the form of citing Trudeau's willingness on separate occasions to accept this or that provision of the accord, as if that were the same as accepting all together. But sometimes it is even claimed Trudeau promised ''special status'' to Quebec during the referendum campaign in 1980.

What, in fact, did Trudeau pledge that night in May in the Paul Sauve Arena? He vowed he would ''renew the Constitution.'' Admittedly this is a vague phrase, vaguer even than ''distinct society.'' But it is a far step to read into it the contradiction of everything Trudeau had spent his entire intellectual and political career attacking.

It is much more plausible to think that what Trudeau was pledging was more Trudeauism: Finally, more than a century after Confederation, Canada would get serious about bilingualism, safeguarding language rights in the Constitution. But thanks to the intervention of the premiers, Trudeau's promise went unfulfilled. The eventual compromise embodied in the 1982 Constitution offered Quebecers - and Canadians - only a watered-down version of bilingualism, and a Charter of Rights filled with exceptions.

It is in that sense, and that sense only, that the 1982 patriation exercise was any sort of ''betrayal'' of Quebec. The remedy for that is not special status, which was never on offer. To keep the promise of a decade ago, we need not less Trudeauism, but more.

BILINGUALISM FAILED

Much of Meech Lake's support in Quebec stems from the belief that bilingualism, notwithstanding the continued existence of almost 1 million francophones in communities outside Quebec, has failed. The intelligentsia have concluded it is best to cut the francophone minorities adrift, and defend French from the redoubt of Fortress Quebec.

But bilingualism has not failed - it has never been tried. From the time of Confederation, the English-speaking majority has consistently refused to take seriously its obligations to the French-speaking minority. Manitoba reneged on the very terms of its admission to Confederation, which were that its legislature, laws and courts were to be bilingual. Saskatchewan and Alberta have likewise evaded their own historic responsibilities, at last revoking them when caught out by the Supreme Court. Ontario dropped French-language education services in 1912, only latterly restoring them.

If, therefore, we are to defeat Meech Lake, which would destroy Canada, without hastening the same end, it will have to be on the basis of persuading the Quebecois that the survival of the French language is not a task to be left only to the Quebec government, but one requiring and commanding the co-operative efforts of all of Canada.

Ontario and Manitoba have gone a long way lately in providing French service in hospitals, social-service agencies, Crown corporations, and the like. But these are hostage to public opinion. If ever there were a time for Ontario to declare itself officially bilingual, a quarter century after the Bilingualism and Biculturalism Commission recommended the same, it is now. Manitoba should follow. And thence, eventually, to the rest of Canada.

For decades, Canada has disregarded minority language rights for the sake of preserving ''social peace,'' a practice to which Quebec is a relative latecomer. Whatever its failings as a matter of social justice, that course is - in cold, practical terms - a luxury this country can no longer afford. At some point, the bigots must be faced down.

That point is now: The very life of the country is at stake. French is not just another ''heritage language.'' It is one of the official languages of the country, with a large bloc that is determined to protect it - if necessary, at the expense of Confederation.

Meech Lake is objectionable, among other reasons, for what it means for the English minority in Quebec. But it is not enough just to ensure the charter overrides the ''distinct society'' clause. If we are to persuade francophone Quebecers that repressive language laws are unnecessary as well as unjust, we will have to assure them that their language is safe in Canada without such measures.

Let the other provinces pledge now to actively support their francophone minorities, with a view to the eventual introduction of official bilingualism. Then will the place of Quebec in Canada, as of anglophones in Quebec, be secure. For then will Trudeau's promise at last have been honored.