Though Woody Allen has had plenty of late-career stumbles, there are still times when he astonishes you with a movie such as Blue Jasmine. This is not one of those times.
Irrational Man is a clumsy, obvious, and desperately unfunny black comedy, one that recycles stale Allen ideas (Crimes and Misdemeanors, Match Point) and contains enough on-the-nose dialogue to warrant both rewrites and rhinoplasty.
All of the tedious overwriting is “help” Allen’s fine cast surely does not need. One glance at the dissolute face of Joaquin Phoenix in his rumpled tweeds tells you most of what you need to know about him — he’s a celebrated philosophy professor, Abe, who’s scaled the heights of academia and is now backsliding, the consequence of personal missteps and general depression.
Irrational Man finds him taking a position at a second-tier university, where he’s a local sensation, and attracts the amorous attention of a starstruck colleague (a funny Parker Posey, who also needs no help from Allen’s labored exposition).
This is a Woody Allen movie, though, so of course Abe finds himself pursued by a much younger woman (Emma Stone). Stone absorbed a good deal of career punishment from Allen in Magic in the Moonlight but — plucky gal — has come back for more, even if her scenes with the shambling, mumbling Phoenix sometimes look less like Woody Allen than a sequel to Zombieland. In any event, her character is purportedly mesmerized by Abe, 
and she insists on an affair. These attentions would be enough to cure the midlife malaise of most men. Abe, however, has found an even more effective tonic — he decides to plan a murder, for what he imagines are morally defensible reasons.
This prompts all sorts of dreary philosophizing — Allen drops the names of Kierkegaard, Heidegger, and others. Unmentioned is Columbo, from whom Allen appears to have borrowed his plot, and the character of the Arrogant Academic Who Thinks He Can Get Away With Murder But is Sure To be Undone By Hubris. The rest of Irrational Man is grindingly familiar — Woody doing Woody, right down to the stifling socio-economic insularity of the setting.
You hope that Allen is satirizing it — using Ivory Tower self-regard as a symptom of some larger malaise.
Curiously, Abe twice makes offhand mention of an associate who became a casualty of the war in Afghanistan. That’s a subject that should interest a fellow like Abe but (pointedly?) does not — he’s absorbed in his own useless and destructive intrigues.
Is Allen trying to draw a parallel between Abe and the know-italls who (mis)managed Afghanistan and Iraq? Or are the Afghanistan references merely non-sequitors in a movie full of sloppy writing? In the context of this mess, hard to tell.