The title is not the only puzzle in Charlie Kaufman’s first ambitious plunge into directing.

It is a movie that will inspire love and hate in equal proportion, an art film with an A-list American cast which is as far away from what Hollywood might call commercial as anything emanating from the auteurs of Europe.

Caden Cotard, the middle-aged theatre director protagonist, superbly played by Philip Seymour Hoffman, is contemplating the failure of both his health and his marriage. His small daughter emits green poop, and the top of a tap hits him on the head while he shaves, necessitating several stitches.

The doctor who does the stitching discovers there is something wrong with one of Cotard’s eyes and suggests he sees a neurologist. Then he has a seizure, and soon pustules begin to grow on his skin.

Meanwhile, his wife (Catherine Keener), a photographer, is befriended by Jennifer Jason Leigh’s lesbian and decamps to Berlin with the daughter for an exhibition of her work. When he rings her, she cuts him off announcing she is now a celebrity.

This is more than his career has amounted to. He is directing a version of Arthur Miller’s Death of a Salesman with an inappropriately young cast at the local regional theatre in Schenectady, New York. To say he is not a happy bunny would be an understatement.

There are, however, women wishing to come to his aid. One is Samantha Morton’s candid Hazel, who gets him into bed but can’t inspire him to have sex. Then there are two adoring actresses — Claire (Michelle Williams), with whom he eventually shacks up, and Tammy (Emily Watson). But none of them can stop his depression mounting.

The totally different second half begins when Caden receives a generous grant after the mild success of the Miller production and decides to mount a work about the human condition in a vacant New York warehouse.

He instructs his ensemble cast to live out their constructed lives as if they are in the outside world of the streets — and the result is a tangle of real and theatrical relationships moderated by a man hopelessly tangled up with his own mortality.

This second hour is what will split audiences asunder. Many will simply not understand what is going on or reject the weirdness. Others will hail Kaufman’s soaring ambition and find the film both poetic and profound.

Without deliberately sitting on the fence, I’m right in the middle of these sentiments. I loved the first half of the film and grew tired of the complexities of the second. It is not that Kaufman is pretentious; it is that he seeks out several different levels at once with the aspirations of a film-maker refusing any compromise.

Synecdoche (pronounced Sih-neck-doh-kee, by the way) is beautifully acted throughout, scripted by Kaufman with the same valorous unorthodoxy as his Eternal Sunshine of the Spotless Mind, and shot with real panache. It’s about someone who can’t deal with “now” and so both regrets the past and dreads the future.

Stricter editing of that puzzling second half might have made it more like the masterpiece some think it.