It says a lot about France that the main topic of political conversation right now is what appears to be an ideological parting of the ways for the Socialist government and left-wing intellectuals.

The past week has seen great chunks of newsprint devoted to such matters as the failure of any reputable writer to publish a book in support of President Francois Mitterrand's two-year-old Socialist experiment and the removal of street signs commemorating the leftist Chilean leader, Salvador Allende. Writers, journalists, philosophers and presidential advisers have been pressed to give their opinion on what government spokesman Max Gallo described as "an ideological victory" of the right.

The intensity of the debate, and the emotions it has unleashed, cannot be attributed simply to the arrival of a journalistic "silly season" coinciding with the summer holidays. Thanks to France's literary and cultural traditions, intellectuals here hold a special moral position that can be difficult for the Anglo-Saxon mind to comprehend. And because of their concentration in Paris, with its dominating hold on all aspects of French life, from politics to the mass media, they have been a major influence on public opinion.

Until recently, it was assumed that the French intelligentsia was predominantly left-wing in outlook. Its great causes have been leftist: the Dreyfus affair at the turn of the century, when a Jewish Army officer was unjustly convicted of treason, Leon Blum's "Popular Front" government of the late 1930s, and the great intellectual ferment produced by the 1968 student uprising.

All that seems to have changed. To judge by the latest debate, French writers and philosophers value the principle of intellectual independence above political commitment. Ideology, at least of the traditional left-wing variety deriving from the works of Karl Marx, is dead.

What is surprising is that this should have happened under a Socialist administration that has gone to much greater lengths to pamper the intelligentsia than any of its right-wing predecessors. As a voracious reader and the author of several books, Mitterrand is himself a French intellectual of the old school. He is said to enjoy the company of writers and sociologists.

The Paris newspaper Le Monde, which is to French intellectuals what The Wall Street Journal is to New York bankers, reported on its front page this week that writers remain as eager as ever to accept an invitation for dinner at the Elysee presidential palace, but no longer try to draw public attention to the fact.

"It's obviously become a little less chic than before to be left-wing," said Regis Debray, the one-time revolutionary who fought alongside Che Guevara in Bolivia and now serves as an adviser to Mitterrand on international relations. Earlier this year Debray angered fellow writers by accusing the host of the popular literary television show "Apostrophes," Bernard Pivot, of acting like a dictator.

Symbolically, much of the debate over the place of intellectuals in French life is being conducted in Le Monde--a newspaper that can't quite seem to make up its mind what attitude to take toward the Socialist state. Over the past year, Le Monde has lost a tenth of its readers as it has wavered between its leftist sympathies and journalistic objectivity.

By contrast another left-wing newspaper, Liberation, has gained circulation, partly because it regards all politicians as fair game.

The Le Monde series on intellectuals was opened by Gallo, a well-known novelist and one of the few intellectuals to pin his colors unequivocally to the Socialist mast. Bemoaning the "crumbling" of the intellectual left and the importation of Reaganite ideas from across the Atlantic, he called on the occupants of literary salons on the Paris Left Bank to start churning out some vigorous left-wing thoughts again.

At stake, Gallo wrote grandly, was not merely "the future success of the political left--but the very destiny of France."

Among the reasons Gallo suggested for the decline in left-wing intellectual commitment was disillusionment with the Communist Party (which belongs to Mitterrand's Socialist-led coalition), the economic recession and political apathy left over from the 1968 student revolution. Many participants in the 1968 upheavals, he noted, decided to make their careers in journalism or business rather than politics.

One of the paradoxical effects of 1968 was the liberation of many leftist intellectuals from their ideological preconceptions. This trend was strengthened by growing public discussion of repression in the Soviet Union and an outcry over the Soviet invasion of Afghanistan and the imposition of martial law in Poland.

The "new" philosopher Bernard-Henri Levy told Le Monde that the "history of a certain type of commitment, a history that began with the Dreyfus affair," had ended. A writer, Alain Finkielkraut, recalled being embarrassed by the "collective hysteria" of the crowds in the Place de la Bastille when Mitterrand was elected president in May 1981. What upset him was the singing of the Communist "Internationale."

"Practically all intellectuals have become fierce anticommunists," said the philosopher Francois George. "As long as the government is prey to the Communist Party, its actions will remain misunderstood."

To this visceral anticommunism must be added a disappointment with the performance of the Socialist government during its two years in office. Many potential supporters among the intelligentsia have been frightened away by the successive policy turns. The pragmatists were upset by the ill-fated experiment in economic expansion at the beginning of Mitterrand's presidency, while the doctrinaire leftists find the present conventional economic austerity measures hard to swallow.

Several prominent left-wing intellectuals, including writer Simone de Beauvoir and philosopher Michel Foucault, refused to respond to Le Monde's questions at all.

So far the only writer to respond to Gallo's appeal directly is the maverick Jean-Edern Hallier, the former editor of "Idiot International," who challenged the government spokesman to a public debate on the "intellectuals and the regime." Gallo ignored the invitation, evidently regarding it as a publicity stunt.