French writer-director Olivier Assayas revisits the themes of change and loss that have imbued many of his earlier films (most notably the superb “Summer Hours”) in “Non-Fiction,” a talky but engrossing ensemble piece set in the world of contemporary Parisian literati. The film embodies the power of words even as it reflects ruefully on how the means of communication are being transformed in a world radically affected by new technologies.

Being a French film, of course, it’s also about pervasive infidelity.

The film begins with a luncheon meeting between writer Léonard Spiegel (Vincent Macaigne), who practices “auto-fiction,” thinly disguised versions of his own experiences, and his long-time publisher Alain Danielson (Guillaume Canet). Their conversation is friendly enough, but Alain is subtly trying to convey that he doesn’t intend to publish Spiegel’s latest submission. Too subtly, in fact: as they return to Danielson’s office, he finds that he has to tell an astonished Léonard bluntly they don’t have a deal.

Spiegel wonders, though, whether the decision was really made on artistic grounds, because he’s worried Alain might have discovered that he’s been having an affair with Alain’s wife Selena (Juliette Binoche), a tart-tongued actress who’s losing interest in her role on a long-running cop TV series. When Selena tells her husband that she rather liked Léonard’s manuscript, it might not have helped his cause, especially because their affair is part of the book, perhaps too thinly-camouflaged for comfort.

Léonard, meanwhile, has some suspicion about his own partner Valérie (Nora Hamzawi). She doesn’t show much sympathy over Alain’s rejection of his latest work, matter-of-factly suggesting that he revise it or simply submit it elsewhere. She’s much more concerned with the political campaign she’s involved with; her candidate, a socialist, appears to be much more on her mind than Léonard’s career is, and at a crucial point in the narrative a crisis in the race will send her scurrying to the politician’s side.

And what of Alain? He’s struggling to keep the publishing house from being sold to a mogul who’s likely to ruin its reputation, and as part of his reorganization efforts to prevent the sale happening he has hired Laure (Christa Théret) to take charge of the firm’s digital transition. Of course he’s also sleeping with the ambitious young woman, who, unbeknownst to him, is involved with a female lover—and considering the possibility of securing a more lucrative job elsewhere.

One could justifiably call this a romantic roundelay of the sort depicted in many other Gallic films, but in this case it’s invigorated by lots of talk from smart but flawed individuals about cultural change, much of it delivered at the breakfasts, lunches, dinners and wine parties that appear to consume much of their time. Assayas adds plenty of wit to the conversations, including a couple of jokes that play off Binoche’s star persona.

There’s also piquancy in the script’s emphasis on the characters’ self-absorption: Alain and Selena have a boy of five or six, for example, but he seems to disappear for long stretches, presumably in the company of the nanny we catch a glimpse of in a beach scene; and though Spiegel’s crisis of confidence is seemingly resolved in the final sequence, one wonders whether the glow of the news Valérie brings him, supposedly the answer to his depression, will last very long. (He’ll probably write about it, though.)

“Non-Fiction” is filled with good performances down the line, and benefits from the sense of pacing in Assayas’ direction and Simon Jacquet’s editing, as well as the cannily unobtrusive cinematography of Yorick Le Saux, who invests the film with an air of unaffected naturalness that’s actually carefully contrived.

The result is another perceptive drama from Assayas, ostensibly more straightforward than his more recent films but equally acute in its observations about the shifting, enigmatic nature of human relationships.