THE CHILDREN of Paradise now in revival at the Key, is justifiably cherished by innumerable movie nuts as the finest romantic film ever made. One could make an even stronger case for Jacques Prevert's extraoridinary screenplay as the finest work of dramatic literature ever composed expressly for the screen.

The late critic Tom Donnelly had several complaints about modern trends in moviemaking, but the most persistent - an umbrella complaint covering most of the others - was "They don't know how to write anymore." Seeing "Children of Paradise" again after a gap of perhaps 10 or 12 years. I was immediately reminded of Donnelly's COmplaint. Here is a movie that is consummately, completely written and its rich variety of satisfactions - the performances, the settings, the atmosphere, the tone, the tempo - are constructed on that remarkable screenwriting foundation, which feels at once solid and expansive.

There have been few pictures in the history of the medium as impressively written as "Children of Paradise," which also had the fortune to be successfully realized by director Marcel Carne, who had already combined with Prevert to create a distinctive style of moody, fatalistic romantic melodrama in such late 30s films as "Port of Shadows" and "Daybreak." Their sixth and most elaborate production, "Children of Paradise" was begun in August of 1943 and first shown in March of 1945. The shooting extended over many months in part to keep everyone working as long as possible during the Occupation. One major role, the ragpicker-informer played by Pierre Renoir,had to be recast when the original actor, Robert Le Vigan, under suspicion of collaborating with the Germans, vanished shortly before the Liberation.

The Occupation seems a strange working atmosphere for a romantic costume picture set among theater people and underworld characters in the Paris of Hugo, Balzac and Daumier. Being aware of the period in which "Children of Paradise" was made may even enchance one's enjoyment of the period illusion that Carne, Prevert and their great designers, Alexander Trauner and Leon Barsacq, contrived to sustain.

While devoid of political content, the film is not without political significance. In its necessarily distanced, stylized way, "Children of Paradise" seems a considerable feat of patriotism - a patrioptic gesture that takes the form of a work of art, celebrating French theatrical figures and traditions and imposing a view of romantic love that might have been attacked as decadently "French" or "cosmopolitan."

Vichy moralists considered pessimistic romances like "Port of Shadows" and "Daybreak" a cause of France's defeat and disgrace. Nevertheless, Carne and Prevert made "Children of Paradise without defering to Vichy morality, which is voiced, ironically enough, by the devious old ragpicker in the closing scences, when he expresses his self-pity by moaning about a general decline of morality. Moreover, "Children of Paradise" is perhaps the crowning illustration of how little "happy endings" have to do with a romantically satisfying story.

Prevert ends his story with all the lovers, noble or ignoble, eating their hearts out, and this despairing resolution feels not only appropriate but also intoxicating.

"Children of Paradise" may produce a particularly heady sensation if one views it in the wake of such talented but frustrating recent movies as "Fellini's Casanova" and "Bound for Glory." which almost seem dedicated to with-holding emotional conflict and satisfaction from the audience. "Children" scarcely seems unsophisticated for being more demonstrative and eloquent.

The characters in "Children of Paradise" reveal that love does indeed have many faces, all of them compelling but few of them indubitably desirable. The yielding but melancholy and unattainable Garance, played by Arletty, is loved, desired and lost in different ways by the dreamy mime Debureau (Jean-LOuis barrault), the flamboyant Shakespearean actor Lemaitre (Pierre Brasseur), the nihilistic, Intellectual criminal Lacenaire (Marcel Herrand) and the snobblish aristocrat Monteray (Louis Salou). The women are no luckier: Fate conspires to separate the true lovers, Garance and Debureau, while Debureau's intense, possessive wife, Natalis (Maria Casares),is devastated by the realization that her husband will always love another woman.

It's a vivid collection of foolish, jealous, obsessed lovers, enchanced by the theatrical and underworld milieux, where analogous passions and melodramas are being plotted and acted out. Prevert develops a marvelous counter-point between on-stage and off-stage drama. Debureau's first mime play, "The Lovers of the Moon," expresses his adoration of Garance, cast as a beautiful statue, and unconsciously dramatizes his own romantic embarrassment: Lemaire, who has been sleeping with Garance, appears as the Harlequin who charms the status off her pedestal.

There are cunning structural devices. The temporary closing of Lemaire's play prompts him to visit Debureau's theater, where the encounters Garance and informs Debureau of her presence, compelling the mime's impulsive exist. Debureau's play is temporarily closed while he goes into seclusion. He attends the opening of Lemaitre's production of "Othello" and finds his beloved Garance in the lobby after the performance.

It seems a very long time since one has heard lines as incisively revealing as Garance's "Love is so simple," or Debureau's "Dreams and life are the same - or else it's not worth living," or Lamitre's "Thanks to you, all of you. I will now be able to play Othello," of Lacenaire's "We could have done remarkable things together. I would have caused oceans of blood to flow for you "The Characters spring to life even if you've never seen the film.

There are certain brief exchanges that create the illusion of speaking volumes. "I love your laugh," Debureau tells Garance, who replies, "So do I. What would I do without it?" Natalie confronts Garance with her jealous love in the world. Oh, you can smile." Garance replies, "I always smile." And so she does: Arletty becomes virtually the cinematic equivalent of the Mona Lisa. The beauty of the conception is that Prevert's Mona Lisa speaks and even articulates the feelings behind the enigmatic appeal, not that any of her suitors heed such a straight forward confession:

"You must understand me. I'm very simple. I can't help being the way I am. I like people to like me. And when I want to say yes, I never learned how to say no." CAPTION:

Picture 1, Jean - Louts Barrault in "Children of Paradise" Picture 2, Arletty threatened with arrest in "Children of Paradise"