In the later chapters of his novel The Unbearable Lightness of Being, the Czech writer Milan Kundera devotes much space to the political and philosophic significance of kitsch - kitsch not simply as precious or pretentious bad taste, but as the aesthetic ideal of a particular world view.

''Kitsch,'' he writes, ''excludes everything from its purview which is essentially unacceptable in human existence.'' It is the construct of sentiment and simple truths, the kind that might move people in a crowd to tears. It is the ideal of advertisers, and of politicians. It is inherently collectivist, if not totalitarian.

''The feeling induced by kitsch must be a kind the multitudes can share,'' Kundera goes on. ''The brotherhood of man will be possible only on a base of kitsch.''

Now, Kundera had only the kitsch of Czech Communism to deal with. But what on earth would he make of that eight-week orgy of kitsch, now approaching climax, the Olympic torch relay?

''Flame of Passion,'' Maclean's magazine trumpeted last week, en route to an eight-page cover story on ''the odyssey that has transfixed the nation.'' No mere media event, this is ''an astonishing outpouring of pride and patriotism.''

Indeed, it transcends earthly concerns altogether. ''Literally thousands of Canadians have touched it in a mystical rite that has swept the country,'' the magazine rhapsodizes, and on and on. This is restrained beside the effusions of the relay runners themselves, many of whom seem in advanced religious ecstasy by the end of their alloted kilometre. ''It's like holding the hand of God,'' one Calgary runner squealed. Oh, please.

The capacity of Canadians for self-delusion has rarely been drawn upon so deeply. And refilling the tank at every opportunity is the relay's sponsor, Petro- Canada. The Crown oil corporation has pumped, at some estimates, more than $50 million into the ''Share the Flame'' campaign, and in pursuit of astonishing outpourings of pride and patriotism it is leaving nothing to chance.

A rotating crew of 750 PetroCan staff work on the relay; more than 80 technical, medical and other support staff accompany the torch, along with a truckful of reporters and film-makers. And just in case anyone should forget for a moment who is responsible for all this, a loudspeaker blares out the Share the Flame theme song, over and over and over again. In a marketing coup, as Maclean's might say, ''unique in the annals of Olympic history,'' more than 6,500 people have been duped into becoming unpaid extras in an extended PetroCan commercial.

This is hardly the first time PetroCan advertising has played upon that desperate national yearning for a patriotism to match the Americans'. The corporation's campaigns, from ''It's Ours! '' to Billy Crawford in the pickup truck to lisping little girls describing Daddy's work are nationalist kitsch, soaked in maple syrup. Its logo's use of the flag would be illegal in most countries. But this is surely the limit.

It is not that PetroCan has defiled a noble ritual with the stain of commerce. The whole thing is base, idiotic and campy to begin with, from the ludicrous lighting ceremony in Olympia, in which a bevy of Greek starlets costumed for a Steve Reeves epic prance about as ''priestesses'' in the temple of Hera, to the torch itself, an effigy of the Calgary Tower made from recycled beer cans.

It was, indeed, those past masters of kitsch, the Nazis, who invented the torch relay. Though invariably described as ''sacred'' and ''tradition-rich'' in the press, the torch relay was nowhere part of the ancient games, nor of Baron de Coubertin's 1896 revival. The general secretary of the Berlin Olympics, the games that confirmed the transformation of the Olympics from belle epoque whimsy to ultranationalist codpiece, cooked it up, to make explicit the link between the Third Reich and the ancient empires of Hitler's fantasy.

3,000 runners carried the torch from Athens to Berlin, through territory the Nazis would later invade, to loud raspberries from the locals. Burnished youth in gym clothes, torches high, thrusting forward - the whole is as redolent of Nazi kitsch as an Albert Speer design.

Of course, there is something powerful about a torchlit parade. The Nazis knew it. So do the Olympic organizers. Ticket sales for the Los Angeles games in 1984 shot up after the torch relay set Olympic frenzy in motion; as Olympic Committee ticketing manager Debra Henry, a veteran of the L.A. games observed, ''the power of that fever . . . there is nothing like it.'' See the film version: Triumph of the Shill.

But never mind. If it makes people smile and shed a tear, what of it? Just that. Anything that can bring a small moment of happiness into the lives of millions ought immediately to be distrusted. The patriotism it evokes is empty of content, a celebration of platitude.

At any rate, for most of the runners one suspects more ego than nation was involved: the relay lets everyone be famous, for 15 minutes or one kilometre, whichever comes first. That's less troublesome, but hi-momism hardly qualifies as ''Passion.''