Renoir, of course: Like cinema itself, Jean Renoir is coming up to a 100th anniversary. Son of the more famous Auguste, was he also the greatest film-maker there has ever been?

ANYONE who has searched with purpose and need in the history of film feels reverence for Jean Renoir. We think of the director as that hoarse, large, gregarious man, if only for his performance as Octave in La Regle du Jeu (1939), the stricken friend to everyone; the belated declarer of his own deep feelings and the helpless cause of fatal mishap. Octave is Renoir in a nutshell: trying to behave well, but discovering that the attempt is not enough, or not reliable. To see him in that film, stirring the action, the director enticed in front of the camera, is to know why actors loved him - and how he enjoyed the act called life.

But that memory is not enough, not even with Thursday 15 September being the 100th anniversary of his birth. It would be too simple to settle for love and gratitude, for nostalgic tribute. One could easily picture the painter's son, born and raised in Montmartre, and taken when he was 15 months or so to see the first movie show, the cinematographe, when the Lumiere brothers put out the house lights and projected moving images on to a screen for an audience. This could be very tidily handled as a bit of centenary serenity. And that is not nearly enough.

For the movies - inadvertently established by the Lumieres, glorified by Renoir and his generation, and still yearned for by such as us - are stumbling at their 100th anniversary, too. Are we confident they will make it to 110? Do we want longevity if it means True Lies or the millennium's ultimate teen F/X sensation? Can we believe that the best directors are working today? There are a few capable of greatness - Theodor Angelopoulos, Chris Marker, Jacques Rivette - and there are masters who are still alive: Bergman, Bresson, Antonioni. But consider our plight if, at the age of 100, we have to weigh the elegant but numb virtues of Kieslowski's Blue, White or Red or wonder whether to take seriously (or just be stunned by) Pulp Fiction and Natural Born Killers.

In a medium 100 years old, the great directors are . . ? Not Griffith, not when Birth of a Nation is too racist to be shown. Welles? Great once, but then launched in his swan-dive of flagrant decline. Eisenstein? An illustrator of genius, not a great director. Murnau? Dead too soon for us to be sure. Fritz Lang? In the end, too bleak, or too satisfied with that. Von Sternberg, Von Stroheim, Michael Powell? A touch too eccentric to be great. Hitchcock, Ford, Capra? Those stocks are going down these days. This is a game, I know, but if you play it hard you don't need many fingers to count greatness: Dreyer, Ozu, Mizoguchi, Ophuls, Bunuel, Hawks, and Renoir, of course.

He made his last movie, Le Petit Theatre de Jean Renoir, in 1969; he had his most fruitful periods in the 1930s and the 1950s. So Renoir might seem like a proper study for museums, or retrospective seasons at the National Film Theatre. Yet what I want to say about Renoir is that in films like La Chienne (1931) and Boudu Sauve des Eaux (1932) you can still feel your senses quickening, as if Renoir's way of showing something is more testing than you're used to. Is, not was. And in The River (1951), say, or French Cancan (1955), there is a mingling of life, society, time, fate and story so open to pain and transience, and yet so assured, that the complexity leaves today's films feeling like the work of show-off schoolboys. These films are still so modern - regrettably, for it means the medium has gone astray.

The important reason for Renoir's greatness, though, is not really the modernity, the freshness and excitement of the telling, but his absolute ease with the largest possible meanings. I say 'ease' because nearly all the movies feel small, local and incidental; these are not thunderous collisions with great themes. But in the way of seeing people, the small stories become emblematic. Renoir taught us to see in the dark, but he had no patience with living there. Though he saw, very early, how film-making uncovered the natural theatrics of life, he could not settle for being an aesthetic connoisseur, much less a fanatic who believed movies were more important than life.

He was the son of the painter Auguste Renoir; in fact, the younger son - the older brother, Pierre, was an actor who can be seen to advantage in some of Jean's films: as the king in La Marseillaise (1938), and as Maigret in the magnificent, but little-known, La Nuit de Carrefour (1932). The convention is to illustrate Jean's childhood with one of Auguste's paintings: the little boy like a peach in the arms of the housemaid, Gabriele. There is no doubting the love that made such paintings, and it is easy to eat the peach - to accept that Jean grew up like a prince in a busy, generous household where creativity, family, meals and sunlight all flowed together.

It may have been that 'perfect' - Jean is fond and rhapsodic in his book, Renoir, My Father - but that doesn't guarantee its being easy or simple-minded. Auguste was crooked from arthritis. Late in life - in Jean's youth, for the father was 54 when the son was born - Auguste had the face of a wicked, bad-tempered tyrant. Even if he was not a painter of the first rank, he was a master of female, unadorned skin. He hired servants with their modelling in mind: it was a household of half-dressed, voluptuous young women. It's not clear what Madame Renoir thought or felt about this, but few subjects so haunted Jean Renoir as those of love getting out of order and infidelity to earlier ties, bringing joy and heartache in fearful harmony. A woman in La Regle du Jeu says that love is just 'the exchange of two fantasies and the coming together of two epidermises'. Renoir the film-maker revelled in human contact and loving touch, but he never forgot that inner solitude - the never fully knowing another person.

The father had other influences. Jean grew up being painted, with people he knew in life on canvas. And not just the people, but the furniture, the pets, the views from the window, the garden in the family house at Cagnes-sur-Mer in the South of France. Renoir's films are abuzz with nature enough to help us see how wild the people are; and he cherished threshold, that state of looking in and out of windows. His camera is as fickle as one of those barometers in which a man and a woman are in and out-of-doors all the time, but never together.

So Jean saw himself as a figure in pictures: life and its double (the use of life as material) went hand-in-hand. No wonder he grew into one of the most reflective dramatists of the precarious balance between life and theatre. This theme reaches its peak in French Cancan, where the impresario Danglarsk is a visionary of dance and show, but a helpless user of young women; and in The Golden Coach (1953), where Anna Magnani, the actress, laments that she is magnificent on stage but a mess in life.

Jean Renoir came of age in time for the Great War. He joined the cavalry and then, having suffered a wound that left him with a rolling limp, he entered the flying corps. It was an important time. While Renoir would make one of the most eloquent anti-war films, La Grande Illusion (1937),

it is full of respect for military life and the old officer class embodied by Pierre Fresnay and Erich von Stroheim.

Renoir's mother had died. His father was nearly crippled. But he painted still, and his last model (a gift from his mother, Jean wrote) was Catherine Hessling. As Renoir fils helped look after his father, so he fell in love with Hessling. She longed to be an actress, and Jean was diverted from ceramics - his first art. He would make movies about Catherine, his wife. That's how he began, in the 1920s, with La Fille de l'Eau, Nana, Charleston and The Little Match-Seller. In the process, selling his father's paintings to finance the movies, he discovered two things - that Hessling was a limited actress, but that he loved movies. The couple separated, but Jean was home.

It is tempting, in hindsight, to surmise that Renoir in the 1930s is one of those supreme examples of an artist discovering his own nature and an intricate medium simultaneously. We see a string of jewels - La Chienne, La Nuit de Carrefour, Boudu, Madame Bovary, Toni, Le Crime de Monsieur Lange, Une Partie de Campagne, La Grande Illusion, La Marseillaise, La Bete Humaine - with that triumphant pendant diamond, La Regle du Jeu turning the set into an exquisite necklace. The truth is more muddled. Renoir had to battle to be himself. La Chienne, once, was taken away from him. Madame Bovary ended up shorter than

intended. Partie de Campagne was so beset with money troubles, bad weather and quarrels that the shooting was abandoned - what seems now like the greatest short story ever filmed was once regarded as an abortion. And when La Regle du Jeu opened, in 1939, it was received with boos and a kind of loathing. 'The failure of La Regle du Jeu so depressed me,' Renoir wrote, 'that I resolved either to give up the cinema or to leave France.'

There was all the turmoil of economic slump and political polarisation: for a time, Renoir was caught up in the fervour of the Popular Front, greatly influenced by the woman he lived with, his editor Marguerite Renoir (they lived together but were not married), who was a Communist. Renoir even collaborated on La Vie est a Nous (1936), a propaganda documentary for the Party. He must have been swayed, yet he was temperamentally less an ideologue than a wary sceptic who rarely believed that anyone was all right or all wrong.

He was developing a way of seeing - deep focus, real locations, naturalistic acting, long takes with a moving camera and wide shots - that was pledged to the notion that life is all a matter of context, circumstances and the multiplicity of points of view. He did not much like close-ups because they promoted fantasy: he was very un-American. Renoir was novelistic - he owed a lot to Flaubert and Maupassant: realistic, tough-minded, tolerant, tender and finally lost in the whirl of life. 'Everyone has his or her reasons,' he is famous for saying - which can sound like benign wisdom. Yet it also means that we never know where we are. Morality slips into anarchy - that is the energy that makes La Regle du Jeu so dangerous. He had a theory learnt from his father that human lives are like corks bobbing along on the current of a river, proud but helpless. In an instant, purpose can lead to disaster; yet the flow never stops. In the 1930s, the many lives are prized, but there was always a sense of fatalism, of the river going where it wanted - and rivers are key in Boudu and Partie de Campagne, lovely yet pagan.

Nowhere is this enigma more evident than in La Regle du Jeu, a tragi-comedy that blends Mozart and Beaumarchais with French high society waiting for the Second World War. Every experiment of the 1930s pays off in this film: the vivid acting so often based on casting against type (for instance, Marcel Dalio, famous as a gangster, as the aristocrat); crowded interiors, the busy house party, the spill of action, all magically organised by Renoir's moving camera and compositions in depth that seem utterly natural; the electric interaction of the absurd and the ghastly, and the confidence that a small story about untidy love affairs can contain all of life. The tone shifts all the time, and it is still a tricky film to adjust to, taking on fresh meanings no matter how often one has seen it.

But the picture flopped: as Renoir believed, the audience was threatened by his portrait of its frailty and by the sense of an era of false ease coming to a close - 'People who commit suicide do not care to do it in front of witnesses.' So he gave up France. After a trip to Italy in 1940, to teach and to attempt to film Tosca, he left for America, not with Marguerite, but with Dido Freire, his new love.

Renoir in Hollywood is a strange story, not least because he loved California. He was seldom happy making films for the Industry, but he got a house and a great garden that reminded him of southern France. He never quite moved back to France to live. He made many friends in America, and he became a beloved host in Los Angeles, where he spent his old age, writing books, and dying in 1979. But not one of his Hollywood pictures is entirely satisfactory, or negligible. He worked for a time for Darryl Zanuck, and called his studio 15th-Century Fox. At about the same time, Fritz Lang, Billy Wilder and many others excelled in American

conditions and the studio system. But the French often have difficulty in America, and Renoir could never find a place for his movie art.

The films he made there - Swamp Water (1941), This Land is Mine (1943), The Southerner (1944), The Diary of a Chambermaid (1945), Woman on the Beach (1947) - are all brave gestures against the grain, fascinating but problematic. They are also increasingly taken over by darkness, or a loss of faith in people. Renoir's Diary, for instance, is a little chillier than the version Bunuel made in 1964; while Woman on the Beach - about a blind painter, his wife and her lover - is a meditation on loneliness and despair.

There was a time after the war when Renoir did very little. He was uneasy about going back to France, in part because Catherine Hessling was still legally his wife, though Renoir had married Dido in America. Nor was he quite welcome in France: some said he had deserted, no matter that the very name 'Renoir' was part of French cultural history. In his fifties by now, Renoir was despondent: he was in America, but he felt sure that Hollywood regarded him as 'not one of us'.

Then he found a project, and an angel: Rumer Godden's novel, The River, about an English family in Bengal; and a florist named Kenneth McEldowney who knew nothing about movies beyond the fact that his wife had been Esther Williams's PR woman. In sublime ignorance and superb hope, the florist wanted to make a picture. And so The River marked Renoir's return, in 1950, as well as his first film in Technicolor. The whole thing was shot in India, and the time there seemed to revive Renoir's faith in himself and his work.

Some have found reasons for taking The River lightly: it is a European's view of India; it has some moments close to tourist documentary; the Godden novel is focused on, and was really written for, teenagers; not all of the acting is assured or smooth. So maybe it could be better. Yet no other film-maker is so dependent on limitation and problem as Renoir - it is as if his art had to conform with life's itching need to avoid perfection. The River is the highest expression of the stream Auguste Renoir talked about; it is time, acceptance and mystical continuity in which, as one child dies - bitten by a cobra in the depths of the garden - so a new baby is born.

The River does not enquire deeply into the lives of characters, and that was new in Renoir (he never stopped trying to extend himself, something all the more striking in an artist who repeated scenes, situations, places and images over and over again). For now, he seemed to feel that in all the crowdedness of life, no single existence counted for too much. He was farther away than ever from the close-up and self-preoccupation. But the kindliness, the respect and the intuition are endless. As a film, The River leans towards music, dance, colour, story-telling and the gentle show of life. In The River, The Golden Coach and French Cancan - three colour films - Renoir delivered a testimony as rich as The Tempest and A Winter's Tale, and as indelible as the late quartets of Beethoven.

It was a sweeping return, and it established Renoir at a crucial time. He became the father- figure to the young critics who became the directors of the French New Wave: he personified cinema for them, and he was enormously influential, especially as La Regle du Jeu was revived and acclaimed in a restored print. But it's easier now, I think, if uncomfortable, to see lessons in Renoir that the New Wave didn't always grasp. They were in love with film, and they sometimes took it more seriously than life. In Renoir, they saw not just a generous man, but a Frenchman who had at least lived as an American, and a director who had refined his art through five decades. Still, Renoir never lost sight of what he was watching, and why: people and their stories. He never became transfixed by film, and nothing but.

Such thoughts are prompted by the looming centenary of Renoir and the medium. Too much of our movie-making has fallen into the hands of young men obsessed with its machinery, but so young in life that they make movies about movies. Jean-Luc Godard was one of that generation who inherited Renoir's cinema. Godard once likened Renoir to Mozart; he named one of his great characters - the one played by Anna Karina in Pierrot le Fou - Marianne Renoir. But Godard also said, about complaints that there was so much blood in Pierrot, 'No, that's not blood, it's red.'

That was once taken as the defiant, witty defense of glorious obsession. But these days we face too much blood to fall for the red answer. In Renoir, it is red and blood; to experience his films is to feel liveliness raised to the level of art. Godard once seemed like a candidate for greatness. He was as innovative in the 1960s as Renoir in the 1930s. Then he became an ideologue, a lecturer and a wilful solitary. Renoir's life and work went through changes - as a river nears the sea it widens and alters. He was always a craftsman, but never one who looked away from the challenge and exultation of life. At 100 years, his achievement repays endless attention, but it cannot leave the film historian or the film-goer especially optimistic about the future. He is the greatest director - of course; but we may begin to add, 'alas'.

'Une Partie de Campagne' and 'Le Crime de Monsieur Lange' are at the re-opened Riverside Studios Cinema, W6 (081-741 2255), from 9 Sept. The BBC will show an 'Omnibus' programme on the director, and a season of his films, in December.