“BPM (Beats per Minute)”

*** 1/2

(Not rated, 2:20)

It is said of one of the characters in Robin Campillo’s “BPM (Beats per Minute)” that “he lived his politics in the first person.” Even in translation and even in a movie set a quarter-century in the past, this suggestive phrase, which is part of a eulogy, cannot fail to resonate. The words, and the passionate, uncompromising sentiment behind them, offer an implicit rebuttal to the currently fashionable critique of “identity politics,” a phrase that seeks to trivialize struggles that are, for the people who practice such politics, a matter of life and death.

The young French AIDS activists — members of the Paris chapter of Act Up — whose meetings, tactics and love affairs fill the dense, absorbing 140 minutes of “BPM” are outspoken in their advocacy of the marginalized. They confront their adversaries with a litany of stigmatized populations — gays, drug users, prostitutes — whose dignity they are pledged to defend. The group’s language is confrontational and its tactics uncompromising, in ways that anyone aware of Act Up in its fierce heyday will remember. Balloons full of fake blood are hurled at government officials and pharmaceutical executives. Meetings and conferences are disrupted. Demonstrators lie down in the street like corpses.

In the long planning sessions that constitute most of the film’s action, the participants are not much nicer to one another. An early scene sets out rules and procedure — finger snaps instead of applause; no debating in the designated smoking area — which are subsequently tested and flouted. Though everyone is committed to the same cause, ferocious quarrels about theoretical and practical issues lead to shouting matches and episodes of lacerating humiliation.

The passion in the after-hours classroom where strategy is discussed and actions orchestrated can hardly be contained within its walls. Friendships form and fracture; rivalries percolate. Sex happens, too. In the case of Sean (Nahuel Perez Biscayart) and Nathan (Arnaud Valois), political solidarity, personal sympathy and sexual attraction deepen into love.

You could say their relationship is the film’s main extrapolitical concern, since Sean and Nathan are the characters whose intimate lives it follows in most detail. But of course the point of “BPM,” and of the movement and moment it reconstructs, is that the personal and political passions can’t be easily disentangled. This is not so much argued as felt. The erotic scenes are dialectical as well as hot; the meetings have a wanton, feverish energy. The air is heady with abstraction and carnality. It’s not a French movie for nothing. (Though it does serve as a fitting fictional companion piece to “How to Survive a Plague,” David France’s magnificent documentary history of Act Up in America.)

In the first decade of this century, Campillo worked as a screenwriter on three films with Laurent Cantet: “Time Out,” “Heading South” and “The Class.” (He also worked on Cantet’s latest film, “The Workshop.”) “The Class” in particular, which chronicled the life of a teacher in a working-class French public school (and won a surprising Palme d’Or in Cannes), was exquisitely attuned to the emotional nuances of institutional procedure. It felt like a documentary in its attention to routine and like a melodrama in the way it galvanized currents of feeling.

“BPM” takes a similar approach. When the group is together working through the items on its agenda, the camera is more participant than observer, and it turns a gathering of individuals into a complex collective organism. You see how people with different ideas and temperaments — as well as different experiences with the disease that brings them together — coalesce into something with a will of its own, expressive of but distinct from theirs. And you also observe the way members of that composite self regain their particularity, changed by their encounter with one another but still very much themselves.

All of this happened a long time ago, of course, but in spite of its historical specificity, “BPM” never feels like a bulletin from the past. Its immediacy comes in part from the brisk naturalism of the performances and the nimbleness and fluidity of the editing. The characters are so vivid, so real, so familiar that it’s impossible to think of their struggles — and in some cases their deaths — as unfolding in anything but the present tense. And even though some of the battles their real-life counterparts fought have been at least partly won, their anger feels urgent and unassuaged. They were fighting for their lives and also forging a template of resistance.

Shown in French, with English subtitles.