Here‘s an irrational thought; Irrational Man is a lousy movie, worth seeing. The reason for that is simple enough; it features yet another stunning performance from Joaquin Phoenix – a performance that deserves a much better film.

This shouldn’t be a surprise – Phoenix is simply one of the best actors working today. The way he holds the screen and commits to a role reminds me of 50s greats like Brando and James Dean. He was always a fine actor but he has been doing his best work for a decade now. When the material matches his talent the result can be movie magic, the brilliant Her and the criminally underrated Two Lovers are proof of that. Then you got a troubled film like The Master – whose real value simply lies in a thespian boxing match between two great actors at the top of their game. A bit like the De Niro-Pacino show-off Heat, although it lacks the emotional punch Michael Mann brought to that 90s classic.

But The Master is still a quality movie, even if the rest of it doesn’t quite match the acting of Phoenix and the late, great Philip Seymour Hoffman. By contrast Irrational Man is simply a shambles. The directing is lazy and so is the script, which is a shame, since the idea behind it is quite intriguing. In other hands this could probably have been a fine movie. But writer / director Woody Allen has been directing one film a year for decades now – it really would help the quality if he occasionally took, say, two years to really flesh a script out.

This tale of Phoenix’s tortured philosophy professor Abe, his two lovers and the murder of a corrupt judge has numerous possibilities for tension – but they are usually wasted, both by a terribly uninspired supporting cast and the most bland jazz music available, music that totally drains the tension out of the few scenes that could have been exciting.

Yet for the first half of the film Phoenix still manages to hold it together. It also helps his is the only role that is decently written – the second lead is Emma Stone as University student Jill, who sounds like no University student ever did. Stone is a fine actress – Birdman and The Amazing Spider-Man were proof of that – but she can’t do much with this criminally underdeveloped role. It’s a big role though – and it gets bigger as the movie progresses and Abe fades into the background. Jill becomes ever so slightly more believable as she takes over as the leading character – but it’s far from enough to offset the fact that she’s not half as interesting as Phoenix’s Abe.

The underused Parker Posey is the only one around who is any match for Phoenix in the acting stakes, playing the promiscuous Rita, Jill’s competitor for Abe’s heart. She has a lot of fun with a slightly written role while the rest of the supporting cast flounders around and the university students are some of the most unconvincing bunch of students ever captured on film.

Still, it should be mentioned the film does throw up some interesting philosophical questions, with Abe being a philosophy professor after all. The root of Abe’s problems seems to be a growing feeling that he believes philosophy to be useless in the face of real-life problems. And if you replace philosophy with filmmaking and think of Abe as the token Woody Allen stand-in, you got an interesting dilemma. The problem is the film never really engages with any of those issues but instead shies away from them – perhaps because its director is terrified of the answers?

Ásgeir H Ingólfsson