Writer/director Christopher Nolan is a brainy filmmaker, no doubt about it, but I'm not sure he's a terribly philosophical one. Inception, Nolan's first film since the eye-rollingly overpraised The Dark Knight, is a mindbender bearing superficial resemblance to other question-reality manifestos like The Matrix and Synecdoche, New York, only minus the giddy pop psychology of the former and the me-myself-and-I self-seeking of the latter.
Strip away Inception's central conceit - that humans can experience shared dreams, and that nefarious deeds may take place while we're poking around in each other's subconscious - and what you're left with is, in essence, a heist movie, with all the familiar tropes of the genre: a conflicted leader who behaves immorally, but for righteous reasons; his assembled team; and the one last job that almost certainly promises our hero's undoing. But it's a heist movie for the ages.
Leonardo DiCaprio plays Cobb, the leader of a crew that traffics in a unique kind of corporate espionage. They design a dreamscape, then trap, say, a CEO into said dream in order to extract information. That's what the team usually does - extraction - but early on, they are hired to do the opposite: to plant an idea in the head of an heir to an energy conglomerate (Cillian Murphy).
This trick, inception, is unproven, and in order for it to work, Cobb's team determines they will have to go much further than a shared dream, but rather into a dream within the dream within the dream. At one point, Nolan thrillingly juggles almost a half-dozen loci on the time-space continuum.
You can't discount the novelty and dazzling invention of Nolan's premise. Certainly he's an able action director, but via the dream anti-logic, he's written himself full license to hurl his film into exotic, often otherworldly locales defined by an altogether other kind of physics.
Nolan's film is typically self-possessed, but what endures is its sense of desperate tumult, as worlds collapse and a broken man tries, badly, to make reparations. While logic tells us that nothing could be less life-and-death than what happens when we dream, experience tells us otherwise. The terrors and ecstasies of our dream life feel just as vivid as, if not more than, what happens outside of REM.
The problem with Cobb is that he can't tell the difference anymore. DiCaprio's character isn't so far removed from his shaky and grieving antihero of Shutter Island, but his blend of unflappable cool and spittle-sob emotiveness is irresistible here.
In the other roles Nolan has cast a terrific assemblage of character actors, including Tom Hardy, Joseph Gordon-Levitt and Ellen Page, who are so watchable that the thinness of their characters comes off as economical rather than as an oversight. Page, playing the newest member of the team, serves as proxy for the audience: As the rules are explained to her, so they are explained to us, and we share in her delight as whole worlds are built anew.
That delight somewhat diminishes as we enter the film's second hour, but it's not enough to ruin what is surely the most engaging action film in years.