If you want to get an idea of what makes "Two Lovers" an exceptionally well-written and directed film, notice filmmaker James Gray's careful selection of detail.

Very little is explicit. The audience is left to infer much from spotty information, and yet a full and specific picture emerges. We are never in doubt of the truth of the characters and the absolute solidity of the world being depicted.

Gray ("Little Odessa"), an American director, has long been a particular favorite of French cinephiles, but this movie marks his first venture into that favorite of French genres, the romantic drama. "Two Lovers" combines positive aspects of both the European and Hollywood traditions. As in a good European film, shots are allowed to breathe. The focus is on character and human emotion. At the same time, the movie shows an American concern for pace and story development. The result is the best of both worlds.

Joaquin Phoenix brings a tremendous weight of truth to his performance, as Leonard, a man in his 30s who suffers from some kind of treatable mental disorder, probably manic depression. He seems distracted and vulnerable, and at the same time has startling flashes of assurance and charm. He blossoms around women. These flashes are not explained, but we never question them. Phoenix ropes all these aspects into a convincing and unique characterization. If this turns out to be his last movie, as he keeps on threatening, he will be going out in a big way.

In the aftermath of a painful breakup, Leonard lives in Brooklyn with his parents, working in the family dry cleaning business. The apartment is full of the accumulations of a lifetime. The walls are covered with pictures of stern, bearded ancestors. It's cozy, with an Old World Jewish aura, and a character mentions the smell of mothballs in the air. The sense of place in "Two Lovers" is strong.

In rapid succession two beautiful women enter Leonard's orbit. His parents fix him up with a daughter of a business associate, a young Jewish woman, Sandra (Vinessa Shaw), from the neighborhood. For some reason, she just likes him. No explanation. There's just something about him that speaks to her. Leonard is similarly attracted to Michelle (Gwyneth Paltrow), who lives in his building. She's a bad bet all around, an emotional wreck and a drug user, and she's involved with a married man. But Leonard sees the world in her.

Watching "Two Lovers" is like life in the sense that you only get the tip of the iceberg, but you see enough to figure out all you need to know, and you're never in doubt that the iceberg is really there. Gray (who co-wrote the screenplay with Ric Menello) makes up for the time he lavishes on scenes by skipping days, sometimes weeks and sometimes months between scenes, so that there's always the sense of forward motion.

The richness of the performances bespeaks a richness of directorial attention. Nothing is wasted. Every line and every shot conveys meaning. In Shaw's gaze, we see the extent to which Sandra loves and thoroughly understands Leonard. And in Paltrow's performance, we see Michelle's self-knowledge and self-dread, the complicated nature of someone who may be adorable and charming but who doubts her own worth, and probably for good reason.

The style is spare. There's not much music, and when it's used, it's effective. In one key scene, Gray keeps Paltrow and Phoenix in a two-shot in which their faces are partly turned from the camera. He denies us, so we want to see more. The movie has only one flaw, a funny one: "Two Lovers" is another movie in which pants and underwear magically become permeable in the face of erotic desire. The standing-up, easily achieved sex interlude has become a movie cliche to rival the 555 phone exchange.

But make no mistake. It's only February, and already "Two Lovers" is sure to go down as one of the best films of 2009.

-- Advisory: This film contains simulated sex, nudity and strong language.

To hear Mick LaSalle talk about movies, listen to his weekly podcast at sfgate.com/podcasts.

E-mail Mick LaSalle at mlasalle@sfchronicle.com.

This article appeared on page E - 1 of the San Francisco Chronicle