`La Maman et la Putain', a classic of 1973, is an essay on male emotional immaturity. Chris Darke looks back
This will do as a thumbnail sketch of any number of young males in French cinema: "He doesn't give a damn, spends his time having sex, going to bistros and reading. His days, I think, are full. Only he isn't happy."

It is the director Jean Eustache's description of Alexandre (Jean-Pierre Leaud), the principal character in his 1973 film La Maman et la Putain ("The Mother and the Whore").

From the nouvelle vague works of Truffaut and Godard, right up to recent films such as Arnaud Desplechin's Ma Vie Sexuelle, the solipsistic, over- cultivated, emotionally anguished young male has been a mainstay of French auteur cinema.

In La Maman et la Putain, Eustache made the defining work of the genre. A three-and-a-half-hour black-and-white epic, Eustache's film takes autobiographical self-flagellation to the extreme; he himself has admitted that "the films I have made are as autobiographical as fiction can be."

The narrative is slim; Alexandre is a feckless young dandy who lives with an older woman, Marie (Bernadette Lafont), a dress-shop owner, the "mother" of the title. Having split up with a girlfriend, Gilberte (Isabelle Weingarten), he picks up a promiscuous young nurse, Veronika (Francoise Lebrun), the "whore" of the title. A menage a trois slowly evolves, but with none of the bittersweet romanticism of Truffaut's Jules et Jim, which was a clear model for Eustache's film. The characters' emotional sores are masochistically scratched by Eustache's poison pen.

Eustache wrote the film for Leaud. He said: "I felt he could go further than he did in the films of Truffaut and Godard; I sense there was potential in him for a certain madness that he didn't express in their films."

The madness here derives from Alexandre's inability to commit to a single woman, which Eustache sums up straightforwardly: "It's the story of a guy who's been left by a woman and who decides that the next one won't leave him. Alexandre makes a monster who will crush him. When Gilberte leaves him, at the opening, he goes and creates Veronika to overcome this loss." Leaud's monologues alternate between splenetic self-justifications, philosophical tirades and curiously nostalgic reminiscences of childhood. The women - talked at, cajoled and coerced by his verbosity - evade him, escape his insistence. The final image of the film is a telling one; Veronika, possibly pregnant with Alexandre's child, throwing up in her cramped room, physically expelling all the words that have been hurled at her throughout the film.

While it would be interesting to consider the film's connection with the current pop-cultural fascination with Seventies kitsch, the more significant historical influence is that of May '68. In fact, the re-release of La Maman could be seen as an indication that the 30th anniversary of les evenements is upon us. But here, the battleground has relocated from the barricades to the bedroom. At one moment in the film, Alexandre recounts a scene he witnessed during the events of May. The police had teargassed some demonstrators who crowd into a cafe and he tells, with a certain wonder in his voice, of how he saw the "beautiful" sight of a cafe packed with people weeping. "A crack opened up in reality," he says.

Eustache's film is, in some respects, an account of the aftermath of May '68, of what happened after that glimpse of another reality had closed down, leaving its participants with the reality of their emotional and sexual lives to deal with.

The film's itinerary is an equally claustrophobic tour of apartments, cafe terraces and parks that Eustache films with forbidding austerity.

Although Eustache made only seven films in 19 years, La Maman stands as the epitome and model of the style of French film-making often dubbed intimiste, restrained in style and acutely concerned with the personal and social lives of the young.

When the film was released in France, it was taxed with being reactionary and misogynist, one commentator seeing in it "the panicked revulsion of men faced with the liberation of women". From this supposedly post-feminist distance, it appears more straightforwardly misanthropic than misogynist. Its intensity has waned little in the intervening 25 years; if anything, the monomaniacal psychodramatic focus has accumulated a density that makes it an invigoratingly uncomfortable experience - a cathartic viewing for anyone emerging from a broken relationship.

It was a film mired in tragedy. The woman on whom Veronika was based committed suicide after the film's premiere and Eustache was said never to have been the same again. In November 1981, at the age of 42, partially paralysed after an accident, Eustache himself committed suicide. His last words were a letter written to the film magazine Cahiers du Cinema. "Have I something ahead of me now? If so, it doesn't interest me much. I have often hoped for a new awakening, to be reborn, to experience anew the joys, the pains and everything, everything. Today I believe that this awakening is too great or too dangerous for the man I am. The opening that gives on to bliss that comes to me in my dreams I can only take to be death."

`La Maman et la Putain' opens at the Renoir Cinema, Brunswick Square, London WC1, on 27 February.