As a writer-director, actor Tim Blake Nelson has made some remarkable, if uneven, films—“Eye of God,” “The Grey Zone,” even “O” and “Leaves of Grass”—but “Anesthesia” is not one of them. A discourse on existential angst in the modern world, the ensemble piece comes across as sadly familiar, and as emotionally desiccated as its pallid characters.

The film begins with a sequence showing Walter Zarrow (Sam Waterston), a popular Columbia University philosophy professor on the verge of retirement, stabbed and robbed while walking home from the campus one night. Collapsing in the vestibule of an apartment building, he’s aided by Sam (Corey Stoll) and Nicole (Mickey Sumner), the couple whose flat he randomly buzzed, and winds up in intensive care.

Before we get to the hospital, however, myriad other plot threads are introduced. One involves Walter’s wife Marcia (Glenn Close), whom he’s stopped to buy flowers along his route. Another focuses on his son Adam (Nelson), whose wife Jill (Jessica Hecht) is about to undergo tests for ovarian cancer. Adam and Jill also have to deal with a mini-crisis involving their teen children Hal and Ella (Ben Konigsberg and Hannah Marks), whom neighbors have observed smoking pot on the roof of their apartment building.

Walter has also been trying to advise Sophie (Kristen Stewart), a student of his who’s distressed by the lack of real human connection in the modern world and has been cutting herself. Then there’s the fact that good Samaritan Sam is actually an adulterer; he’s staying with Nicole while trying to fool his suburban wife Sarah (Gretchen Moll) that he’s on a business trip in China while she’s seeing to their young daughters at home. Perhaps unsurprisingly, she drinks too much—something her older daughter calls her out on.

Finally there’s a subplot focusing on angry addict Joe (K. Todd Freeman), a street thief who’s forced into rehab by his friend Jeffrey (Michael K. Williams). Joe checks himself out of the treatment center on the very night of the attack on Walter, and the two men meet shortly before the assault, though not with the result you might expect.

There are a few moments in “Anesthesia” that ring true, but for the most part the characters come across as sketches and the dialogue is painfully unconvincing. Sophie and Hal, for example, are the sort of hyper-articulate youths that come right out of a word processor rather than the real world, and Joe’s verbal rampages, while strongly delivered by Freeman, have a theatrical tone at odds with the authenticity Nelson is striving for.

But by far the worst offense is Professor Zarrow’s career-closing speech to his philosophy class. Walter’s dialogue throughout has had a spuriously intellectual tone, but the long monologue he offers about two-thirds of the way through the film is particularly egregious, a disquisition on seeking answers to the deepest questions that’s supposed to be profound, in the avuncular way that Waterston’s so expert at, but instead sounds like a string of clichés. Even that wouldn’t be so bad if it weren’t followed by an explosion of applause from the class, a reaction that can only make one wonder at the acuity of Columbia undergrads.

One might be attracted to “Anesthesia” by Nelson’s prior track record and by its formidable cast. But neither is in best form here. This kind of interconnected plot requires structural cleverness, but in this case the construction feels arbitrary, with the plot threads simply shuffled rather than carefully arranged, though it’s obvious from the start that the picture has to be bookended with Walter’s stabbing. As for the actors, they’re straitjacketed by the relative brevity of their roles, effectively forced to work in shorthand strokes rather than gradually building nuanced characters. The same perfunctory tone pervades the technical side of the film, with Christina Voros’ camerawork workmanlike rather than distinctive.

The title of the movie almost invites some observation about putting you to sleep. Unfortunately, that sort of comment isn’t out of place.