A co-founder of the legendary Magnum photo agency, along with Robert Capa, David Seymour and George Rodger, he is seen today as the leader of that generation of photographers who succeeded in elevating what was until then a hobby, or at most a jobbing profession, into an art form.

Among his most famous images, many of them on display at the foundation bearing his name that was opened in Paris last year, are the moustachioed, bowler-hatted man caught peeping through the canvas surround at a sports event in Brussels in 1932; a female prisoner denouncing a Gestapo informer in 1945; a boyish Truman Capote in 1947; and children playing on the Berlin wall in 1962.

As a photojournalist, he had an astonishing ability to be in the right place at the right time: among the 1,000 original prints, as well as contact sheets, films, manuscripts and correspondence, at the foundation are shots taken during civil wars in Spain and Mexico, the communist revolution in China and at the death of Mahatma Gandhi in India.

He was also a gifted portraitist, counting Jean-Paul Sartre, Carson McCullers, Bar bara Hepworth, Henri Matisse, Edith Piaf and the Duke and Duchess of Windsor among the famous names who sat for him. In 1954, he was the first western photographer allowed into the Soviet Union after the death of Stalin the previous year.

Born in 1908, the son of a wealthy industrialist from Chanteloup, east of Paris, Cartier-Bresson took up photography in the 1930s: his first Leica (“an extension of my eye”), bought in 1932, was intended merely as an aid to his art. Much later he returned to this view, dismissing photography as “un truc micanique” – a mechanical thing – and spending most of his time after 1974 drawing and copying paintings in Paris art galleries.

But Cartier-Bresson’s studies on design and proportion under the painter Andre Lhote, in the 1920s, proved fundamental to his photographic philosophy, as did his work on surrealism, a movement then at its height.

From these two roots gradually grew his definition of what makes an exceptional image, the “decisive moment” — the name given to a major collection of his work in 1952. The “decisive moment,” he said, was “the simultaneous recognition, in a fraction of a second, of the significance of an event as well as the precise organisation of forms which give that event its proper expression.”

Using one of the unobtrusive, fast-shooting cameras that became available from the 1930s, Cartier-Bresson began his hunt for the arresting image, setting the standard for every photojournalist who followed. He was, in his words, “prowling the streets … determined to trap life, to preserve life in the act of living.”

Before the war he worked in eastern Europe, Spain and Mexico, and was assistant to the director Jean Renoir on a number of films. Cartier-Bresson was imprisoned by the Germans in 1940, but escaped three years later and witnessed the liberation of Paris.

Cartier-Bresson would never nominate a favourite photograph of his own. But in a 2003 exhibition of his favourite works by others, pride of place went to a 1931 snap by the Hungarian Martin Munkacsi, portraying African boys playing in Lake Tanganyika.

“When I saw that photograph of Munkacsi, of the black kids running in a wave, I couldn’t believe such a thing could be caught with the camera,” he said. “I said damn it, I took my camera, and I went out into the street.”

France, its politicians, its commentators, even its Jewish leaders, was outraged by Mr Sharon’s comments (made, it should be said, to an audience of visiting American Jews who thoroughly approved, the American Jewish community being seemingly convinced that life in France is unbearable for anyone in a skull-cap).

There are probably many reasons why Mr Sharon chose to say what he said, few of which have anything much to do with anti-semitism in France and many more to do with Israel’s failure to keep its stream of immigrants flowing.

But, when it responds to provocative comments by Israeli prime ministers and when it beats its collective breast so fiercely about anti-semitism (as President Chirac did this month in a magnificent speech on the racist attacks “soiling” the country, and as the whole nation did a few days later after what turned out to be an imaginary attack on a young woman by six Arab youths), France is missing the target.

That is not to say that France does not have a problem with anti-semitism; it does. There are three main kinds of anti-semitism here. There is the old, ingrained, Catholic kind, those unspoken and unchallenged assumptions that put Captain Dreyfus on Devil’s Island and that still produce, in polite conversations at middle-class dining tables, the kind of remarks you would never hear in London or New York.

A new kind is also perceived by the Jewish community, that of the intellectual left, the Rive Gauche penseurs, whose anti-Israeli polemics are interpreted, by extension and by association, as in essence anti-semitic.

And thirdly, there is the nastiest, the most violent and the most visible kind: the anti-semitism of disaffected youths, mainly of north African origin. This is partly unthinking, knee-jerk violence, a half-baked spin-off of the intifada – the number of attacks on Jews in France follows almost exactly the same curve as the bloodshed in the Middle East. Mixed up in the motivation, too, is all the resentment, frustration and envy of an underprivileged group prompted by the perceived advantages of another.

The common consensus is that this last kind of anti-semitism is responsible for almost all of the recent anti-semitic physical and verbal assaults registered against Jews in France: 510 in the first six months of 2004, up from 593 in the whole of 2003.

But this consensus view cannot be backed up with statistical evidence, because in France there are no statistics to show exactly how many attacks on Jews are carried out by angry and disadvantaged Muslim youths. In fact, there are no statistics to show how many Jews there are, or how many Muslims. And that, in itself, is an indication of where the real problem lies.

For it seems to me that the real racial and religious problem in France, the real time-bomb quietly ticking away at the heart of 21st century French society, is not anti-semitism, but France’s absolute failure, over the past 50-odd years, to properly integrate its Muslim community (estimated, and only estimated, at 5-6 million strong).

France has created a genuine racial underclass, disadvantaged and discriminated against daily in terms of housing, education and employment, living in those decaying, crime-ridden, immigrant-filled, out-of-town sink estates in which France has sadly come to specialise. And until France understands this, it will not able to address what lies behind its intensifying climate of anti-semitism.

The problem of failed Muslim integration in France is made 100 times worse by the nation’s profound inability to recognise it. The very principles of the Republic – the watchwords of Liberty, Equality and Fraternity that have supposedly governed this country for more than 200 years – prevent it from doing so.

For the most sacred article in all France’s grand republican and secular creed is the principle that everyone is equal and indistinguishable in the eyes of the state: no matter where they come from, all French citizens are identical in their Frenchness. In the much-vaunted “Republican model of integration”, all immigrants go through the Gallic mill, shedding their ethnic and religious differences and emerging as shining new French citizens. In theory.

In practice, this explains why France cannot say, and does not know, how many citizens it has who are of north African origin, or who are Muslim, or who are Jewish. For the purposes of the Republic, it simply does not matter.

It explains too why France does not know how many children of its north African immigrants leave school without useful qualifications, or fail to get a job. (Only unofficial reports are available, for example, to show that unemployment among 20 to 29-year-olds of north African origin is currently up around 40%, against 10% for youths of French origin.)

It also explains why France cannot make any attempt to introduce programmes of positive discrimination; make extra resources – in education, for example – available for specific ethnic groups; encourage companies to hire north African staff; make sure there are Arab presenters on TV and Arab politicians in the national assembly; undertake what is really needed: a massive, society-wide effort to raise the status of an entire community.

To do so would be to reject part of the very bedrock of France, to admit that the Republic has, quite simply, failed 6 million of its citizens. For those 6 million, there may be a fair whack of fraternity, but it is true to say that there is precious little liberty and far, far less equality.

Few French people, of course, and even fewer French politicians, are prepared to acknowledge this horrifying hypothesis. (Typically, one of the very few who has is the hyper-realistic young presidential hopeful Nicolas Sarkozy.) Unless and until they do, France’s recent upsurge in anti-semitic violence looks like just the tip of a potentially disastrous iceberg.

It is, in secular France, a heretical notion indeed, that the grand founding ideals of the nation are now obstructing its progress, blinding it to its biggest problems, preventing it from addressing its most critical issues. But that is, I believe, the case. Anti-semitism is, to use a common French phrase, the tree that hides the forest.

A white paper presented yesterday by five MPs from wine-making areas says the decline could be halted by giving wine a special legal status, reclassifying it as a foodstuff with nutritional value, and advertising its beneficial and healthy properties.

Doctors disagree. They point out that alcohol is responsible for about 40,000 premature deaths a year in France, and that one of the government’s recently stated public health objectives is to cut alcohol consumption by 20% within five years.

It is an emotive subject in the land of Bordeaux, Burgundy, Beaujolais and Champagne, where the wine industry not only employs a quarter of a million people but carries enormous cultural and historical weight.

“We’re talking two incompatible realities here,” said Michel Reynaud, a psychiatrist who specialises in addiction.

“There’s the public health reality and the commercial reality of production and marketing. The two will never meet; they can’t. They are poles apart.”

To the wine industry it is evident that the fall in domestic consumption is due less to lifestyle changes than to decades of government policy aimed at combating alcoholism, the white paper says.

“People have simply jumped to the wrong conclusions. Wine is assimilated with every other toxic product, with no distinction made between excessive and moderate consumption.”

Paul-Henri Cugnenc, a surgeon, winemaker and MP, who wrote the most controversial part of the white paper, Wine and Health, said wine in moderation deserved a place in all balanced diets.

The report adds that studies show that two to three glasses of wine a day can substantially reduce the risk of coronary or cardiovascular problems.

Doctors say two-thirds of the deaths in France attributed to alcohol, either directly from fatal illness or indirectly via accidents, murders and suicides, are due to excessive consumption of wine.

They also stress the dangers of the term “moderation”.

Dr Reynaud said: “It’s a terrible trap. Everyone defines for themselves what moderation is. Almost all excessive drinkers consider themselves within the norm.

“What is needed is more publicity on the dangers of alcohol, not encouragement to drink ‘moderately’.”

The wine lobby wants the government to exempt wine at least partially from the Loi Evin, a 1991 law which bans alcohol adverts on television and in the cinema, and limits those in the print media to factual information.

The white paper argues that the winemakers must “urgently” be allowed to promote moderate wine consumption. But Emmanuel Leforet of the French Medical Association said: “Relaxing the Loi Evin for wine would be a flagrant breach of stated health policy.”

The couple’s lawyer, Emmanuel Pierrat, said they would appeal against the ruling, taking their case up to France’s supreme court and, if necessary, to the European court of human rights. He said the pair would remain legally wed until the appeals process had been exhausted.

“We have every confidence that these higher courts will have a slightly more avant-garde view of the concept of a family,” Mr Pierrat said. Mr Charpentier promised to “fight to the end  But this time we will win because we have faith in our country”.

Within hours of the ceremony, the interior minister, Dominique Perben, demanded the marriage be annulled “in conformity with the law”. The public prosecutor had also said the union was illegal because France’s civil code did not permit same-sex marriages. Noel Mamhre, the campaigning Green MP who conducted the ceremony in his capacity as mayor of Bhgles, was suspended from his post for a month for “ignoring the warnings of senior government figures” and “gravely misunderstanding his duties as an elected official”.

He said yesterday he was determined to take the struggle further. “It would have been a revolution if the ruling had gone the other way, because they came under pressure from the authorities,” he said.

A recent poll showed 64% of French people in favour of same-sex weddings.

Gay rights activists hailed Mr Chapin’s and Mr Charpentier’s wedding as a victory for tolerance, but the Catholic church and conservatives denounced it as an attack on the very fabric of French society, insisting that children needed a mother and a father and that the issue was too serious to be decided in a hurry.

Politically, the issue is embarrassing both right and left. President Jacques Chirac and the prime minister, Jean-Pierre Raffarin, have been trying hard to court the gay vote but were obliged to abandon the effort in the face of ” le mariage de Bhgles “.

The left is divided on the controversy: several leading figures, including the former prime minister Lionel Jospin and his family affairs minister, Sigolhne Royal, have said they disapprove; would-be modernisers such as Frangois Hollande, Ms Royal’s partner and the party’s general secretary, are in favour.

Even the popular Socialist mayor of Paris, Bertrand Delanoe, France’s most senior openly gay politician, finds himself in difficulty. While he has declared his support for gay marriage, and condemned the sanction meted out to Mr Mamhre, he has refused to authorise any same-sex weddings in Paris until the law allows them.

Mr Mamhre argues that nowhere does the French civil code state that a marriage cannot be celebrated between two people of the same sex, and points out that it is an overriding principle of French law that “that which is not specifically outlawed is permissible”.

On July 9, she walked into her local police station and described the fictitious attack. None of her fellow passengers moved a muscle as the youths slashed her clothes, cut off locks of her hair, knocked over her 13-month-old baby’s pushchair and scrawled swastikas on her stomach with a marker pen, she said.

She retracted her story four days later, saying she had inflicted the wounds on herself.

Asked by the judge, Jean Idrac-Virebent, if she had not realised that her allegations of anti-semitism  she is not Jewish  would “unleash passions”, she said she had not. Asked why she had pointed the finger at north Africans and black people, she said: “When I watch the telly, they are always the ones who are blamed.”

Her lawyer, Christophe Deltombe, stressed that his client was “well aware that she has deeply upset a lot of people”, but that “at no time whatsoever did she seek the publicity that this affair has received”.

Leblanc’s family said yesterday that she wanted to put the episode behind her. She told investigators she made up the attack, which sparked outrage in the media, so her boyfriend would spend the day with her.

“She’s always told stories, since she was very small,” her older brother, Jean-Baptiste, told French radio. “She told me so many that I stopped listening.”

Her mother, Genevieve, said Marie-Leonie had “told a lot of lies” as a girl, “not in a wicked way, but to grab attention, like many kids”.

The public prosecutor told the court that on six occasions between 1999 and 2002, Leblanc had filed formal complaints about assaults that had never been investigated because they could not be substantiated.

“It was the SOS of a young woman who was depressed, who didn’t know what to do,” her mother said. “Then she was caught up in the whole spiral.”

A psychiatrist said Leblanc had “a strong need to be acknowledged, no matter what the price”.

Her mother said Leblanc was now “getting better”. She had started a course of treatment and planned to finish her studies to become a management assistant.

“This trial should help her stop the lies.”

The incident caused uproar in France, which is highly sentitive to allegations of anti-semitism. Days earlier, President Jacques Chirac had demanded a determined fight against racism and all other forms of intolerance that were “soiling” France.

Soon afterwards, the Israeli prime minister, Ariel Sharon, urged French Jews to flee to Israel to escape “the wildest anti-semitism”.