It has been my experience that there is no such thing as a bad Abbas Kiarostami movie; many people have had a different experience altogether of course, for it's fair to say that Iran's best-known director is among the most contentious and divisive of modern filmmakers. But I'm not going down that rabbit hole. Again, it's been my experience that there's no such thing as a bad Kiarostami movie, but the last decade or so has certainly borne witness to some undeniably "minor" Kiarostami movies: ABC Africa and Ten and some of the several anthology segments he's put together since then are enviably smart, challenging films, but not up to the standard he set for himself in the 1990s.

Like many directors in a stalling career, Kiarostami found a new muse in France, where he made the first film of his career outside of Iran, and the best thing he's done since 1997's Palme d'Or winner Taste of Cherry: this is Certified Copy, a remarkable meditation on the meaning of art, love, history, and the definition of reality couched inside a two-hander between Juliette Binoche, who won Best Actress at Cannes for a rich, warm, and prickly performance as good as anything she's ever done, and William Shimell, an opera singer making his film debut. By this point, the film has been hashed apart by a great many writers smarter than I, but sometimes film festival schedules just don't break open the way you'd like them to, and you end up getting stuck waiting for a heavily-feted picture to get its wide - make that "wide" - release. In other words: I know that being all goofy for Certified Copy is so 2010, but you have to wax rhapsodic over the modern masterpieces you've seen, not the ones you wish you'd seen.

The film opens in a reasonably large city in Tuscany, though we're not made privy to which one, and this will be good practice for getting used to the aggressive opacity of Kiarostami's script. An British author, James Miller (Shimell) is in town giving a lecture on his new book Copia conforme - Certified Copy - a title he much prefers to the English publisher-mandated Forget the Original, Just Get a Good Copy. In the audience, briefly, is a woman (Binoche) with a restless preteen son (Adrian Moore), who longs to have a serious talk with Miller, given that her business selling antiques dovetails so neatly with his book's topic, the status of original artifacts versus copies throughout history. They end up talking a drive into the country, he autographing books as she prattles about her shallow sister, whose worldview Miller finds absolutely compelling.

In a small town a reasonable distance from the city, they stop to take in a museum with its own historic copy - Miller is only marginally impressed, to the woman's annoyance - and then drop into a café, near to halfway through the film. Miller steps out for a phone call, and the owner of the place (Gianni Giachetti) commiserates with the woman about husbands and their annoying ways, but it's just what women have to put up with. The woman does not correct her, and even tells Miller when he returns that she's claimed that they're married, and then we launch straight into Kiarostami Land: from this point on, Miller and the woman increasingly act as though they are married, and it gets clear in bits and pieces that nothing we've seen specifically forbids the possibility that we've been watching the relationship of a husband and wife of 15 years who have grown apart almost to the breaking point. Or it could be that the pair has decided to play act for an afternoon, for reasons of their own. It's even terrifyingly possible that at some point in the movie, Miller and the woman change identities outright - in particular, Miller never once speaks a word in any non-English language until the second half, when he abruptly becomes smoothly fluent in French - and this is the heady, unquestionably schematic and overdetermined and pretentious but oh my god so very intellectually thrilling stuff of the whole movie, which is concerned with just about every topic under the sun except for answering that central question: are they married or aren't they? Which, spoiler alert, is left as unresolved as possible.

The film's narrative is primarily an explication of its stated themes, which have to to with the reliability of representation and truth: at its broadest, this idea is expressed as an implicit invitation to recall that Certified Copy is not at any rate a depiction of a man and woman who are or are not married, but of a man and woman written down on paper and then played by a famous French actress and a British opera singer - an idea highlighted when Miller points out that even the "original" Mona Lisa was only a copy of the real life Lisa del Giocondo. That is, there is no truth in any art, only the copy of truth; though this is not a bad thing in itself, given that the copy allows us a new perspective on the real thing. Binoche and Shimell may be playing a married couple or they may be playing strangers playing a married couple, but in all cases we are still being given a fictional window on the lives of two people who once loved each other and now are uncertain if they still do, and the value of that window changes, but is not wiped out, based upon which level of representation leaves it "real".

Certified Copy is the kind of movie you can't even talk about without sounding like an asshole English major.

The whole movie is full of arguments like that, and the longer it goes on the denser it becomes, not just from listening to the words the two actors speak, but backing up and taking a wider view, one in which the Iranian filmmaker is deliberately copying the idiom of European art films and reflecting that genre back upon itself (the movie is heavy with echoes of other works of cinema, with Voyage to Italy and Before Sunset striking me as the most obvious). Luca Bigazzi's absolutely extraordinary cinematography captures the light and textures of Tuscany in a manner that is pictorially beautiful while also showing a journalistic precision for detail; yet it's impossible not to reflect that every immaculate shot and perfect camera movement is a fictive construct - which doesn't make them less beautiful or make the film less of an advertisement to Visit Glorious Tuscany. It helps of course that so much of the film is shot through glass and reflections, in which compositions beautiful in and of themselves are simultaneously used to obscure or distort whatever we think we're looking at. And so on, and so forth.

It's impossible to get around it: this is a magnificent accomplishment. If it were nothing but a harrowing personal drama about a marriage disintegrating, it would still be essential viewing, but even with two amazing performances fleshing out that marriage, that might be the least interesting thread of the whole feature (after all, we're not exactly hurting for dramas about disintegrating marriages), and the fact that Kiarostami is able to blend that narrative with extremely talky dialogues about the nature of representation that should be dry and sophomoric but are fascinatingly staged and impeccably acted, and illustrate those arguments with the very construction of his movie... or perhaps it's that those conversations contextualise a cinematic structure that takes precedence over the trappings of the script? Certified Copy is a movie with no answers that demands quite a lot of hard work, but it's an inexhaustible thought experiment made by a remarkably talented film crew. I saw it nearly a week ago and it's taken me this long to work up the guts to write a review; that's the best praise I can give to a film that is so over-laden with notions that it will take, I daresay, many more weeks until I've even started to get on top of what it's doing through visuals, through writing, through acting, and through its mere existence.