Of all the political about-faces performed by France's Socialist government, perhaps the most startling concerns the century-old dispute about how French children should be educated.

The first half of the U-turn was accomplished last summer when President Francois Mitterrand shelved controversial plans to increase state controls over private Catholic schools, which are attended by about 16 percent of French schoolchildren. The Socialist government's proposals had touched off a nationwide protest movement culminating in a Paris street demonstration by more than 1 million people.

Today came the second stage of the educational change of course with the government's approval of a conservative curriculum for state primary schools. The new curriculum represents a sharp shift back to traditional teaching methods following a 15-year period in which French schoolchildren have been encouraged to find out about the world for themselves.

Banished from primary schools under the new program are the so-called "awakening activities" -- the nature rambles in the countryside and the involvement of schoolchildren in individual projects that became fashionable after the student upheavals of 1968. Their place is to be taken by a new emphasis on instruction in the "three Rs": reading, writing and arithmetic.

"It's the end of recreation, '68 style," commented the Paris newspaper Le Monde in a report on today's Cabinet meeting.

The educational U-turn is all the more remarkable because it is taking place under the aegis of a minister with impeccable left-wing credentials, Jean-Pierre Chevenement, who heads a Marxist splinter group in the Socialist Party known as Ceres.

Cordially detested by the right when he served as minister for industry, Chevenement now finds himself in the unusual position of being cheered on by conservatives and denounced by fellow Socialists.

"We don't see any difference between Chevenement and a right-wing minister of education," grumbled Jean-Claude Guerin of the left-wing teachers' union SGEN.

The Socialists came to power in May 1981 believing that they had a special mission to update the French educational system. More than half the party's deputies in the new National Assembly were teachers or former teachers -- leading wags to dub the new government "La Republique des Profs." The Socialist election manifesto proclaimed proudly that education reform was a special priority for the left.

In addition to declaring a cease-fire in the Catholic school war, Chevenement has taken what supporters of his predecessor, Alain Savary, depict as "a step backward 50 years" by insisting on the virtues of "instruction" and "elitism" rather than "education" and "democracy." The minister's personal slogan, repeated in classrooms and lecture halls around the country, has been "merit, effort, patriotism."

Chevenement's new curriculum, which comes into effect next fall, restores the great French classical writers to favor in the classroom. Grades and examinations are back in fashion, and dates and facts are to supplant social trends as the stuff of history. Primary school children will be required to demonstrate that they are "able to fill in a blank map of France with the main rivers, towns, mountains and industrial centers." Civic education classes are to be restored.

Dismissing the concern of progressive educators with teaching children "to learn to learn," Chevenement remarked sarcastically: "The best way of learning to learn is to learn something to begin with." He has complained that at present 20 percent of French schoolchildren do not even know how to read adequately by age 11, when they leave primary school.

The new minister's emphasis on the inculcation of knowledge and old-fashioned discipline has been praised by one of France's leading conservative education lobbyists, Guy Bayet, as "the most beautiful change of course since 1968" -- the year of student upheavals, epitomized by the slogan "from now on, it is forbidden to forbid." The head of the pro-Socialist CFDT trade union, Edmond Maire, grumbled publicly that Chevenement's approach to education problems "sends shivers down the spine."

Chevenement has answered his left-wing critics by arguing that his attempts to improve education standards are designed to favor working-class children unlikely to benefit from extra tutoring at home. In a recent interview with the Paris newspaper Le Monde, he insisted that "everyone should be given a chance" to win a place in the elite.

The conservative twist in the Socialist government's education policy has been welcomed by many parents alarmed at what they see as declining standards in public schools. The past year has seen the publication of a succession of books with such titles as "The Massacre of the Innocents" and "Do You Really Want Idiot Children?" -- a counterreaction to the progressive ideas that were dominant in the 1970s.

More surprisingly, perhaps, a recent poll showed that a majority of French schoolchildren are in favor of greater discipline in the classroom. Asked whether teachers should display more authority, 54 percent of those questioned said yes, against 43 percent who said no.

After greeting Chevenement's appointment as education minister last July with skepticism and some fear, leaders of the Catholic schools lobby now seem to be considerably reassured. Canon Paul Guilberteau, who organized last year's massive demonstrations, said that what started out as a tactical change of heart by the government now seemed to be developing into "an ideological turning point" as well.

"After abandoning their ideal of a unified lay system of education, the Socialists have moved onto a new battleground. Chevenement is trying to revitalize the public schools and has decided to leave us alone," Guilberteau said.

The change of ideological course has been combined with the launching of an ambitious $200 million program to equip all French state schools with microcomputers by the end of the year. Announced last month, the program is designed to make French schoolchildren familiar with modern technology and to speed up the country's painful industrial transformation.

Progressive educators, aware that the mood of the times is against them, take comfort from the knowledge that school reforms can take an exceptionally long time to implement.

"There is a huge gap between the speeches made by a minister and the real world of the classroom. It takes years to introduce real changes into a country's education system -- and Chevenement hasn't got that much time," said Guerin.