“The proudest, stubbornest, most obstinate, in other words most free, film in the world” went Jean-Luc Godard’s 1959 description of “The 400 Blows,” François Truffaut’s 1959 film about neglect and petty crime in Paris.

The quote appeared in Cahiers du Cinema, the influential film journal that was also a holding pen for the gang of ardent young cinephiles that broke onto the French filmmaking scene at the end of the 1950s and altered the course of cinema. Leading the charge was Truffaut’s smash-success debut feature, an unforgettable portrait of a boy from a broken home.

As with Orson Welles and Godard, whose nervy, brilliant first feature,”Breathless,” was released the same year, Truffaut’s debut release, made when he was 27, assured him a place in the canon. “The 400 Blows,” a restored print of which arrives at Film Forum today for a two-week run, is sincere and touching, unsentimental, and funny, and features a remarkable performance by 14-year-old Jean Pierre Léaud as troubled Antoine Doinel.

Neglected by his derelict parents, Antoine skips school and guides himself around Paris, stealing things and trying charmingly to return them. His Paris is grimy, seedy, abandoned, and brimming with possibilities.

Mr. Léaud would play Antoine in four more Truffaut films, helping the director’s suite of semi-autobiographical films give birth to arguably the most richly drawn character in cinema. But “The 400 Blows” captures Antoine at his youngest and most vulnerable — nowhere more so than the famous freeze-frame close-up that ends the film.

“Everyone is always haunted by that final image,” the producer of Criterion’s “Adventures of Antoine Doinel” DVD box set, Curtis Tsui, said. Yet Truffaut, who died in 1984, maintained that it was a mistake: He’d wanted Mr. Léaud to fix his gaze on the camera for that final shot, but the actor turned his eyes away too fast.

Though the technique is now a cinema cliché, ending a film on a freeze-frame was unheard of in 1959. Truffaut’s fix, if that’s what it was, proved the final Midas touch. “Every edit feels right, every performance feels right,” Mr. Tsui said of the film. Truffaut, who had been nervous about his inexperience before making it, put his finger on something touchingly pure and natural. It’s impossible not to detect it when Antoine is exultantly pressed against the wall in a spinning amusement ride — “even if you’ve seen it 18 times,” as Mr. Tsui estimates he has. Plenty of people out there can top him.

Film Forum is screening “The 400 Blows” along with “Antoine and Colette,” Truffaut’s 30-minute featurette that finds Antoine living on his own in Paris, working at a record factory by day and attending classical music concerts by night — and falling in love. The object of his amour fou (Marie-France Pisier) is based on a girl whose attentions Truffaut and Godard vied for in real life. Neither one got her in the end. The lack of closure in both “The 400 Blows” and this beautiful, bittersweet follow-up is part of what makes them so compelling. In chapters, Truffaut and Mr. Léaud put a life on film that is vibrant, romantic, indelible — but forever a struggle.

Through October 9 (209 W. Houston St., between Sixth Avenue and Varick Street, 212-727-8110).