Take a look at the photo above. It’s the most poetic image to have emerged from Todd Phillips’ “Joker,” and the reason I say “poetic” isn’t just because the shot has that caught-in-action indelible vibe of a quintessential movie poster: graphic, hauntingly composed, a bit shocking (at least, the first time you see it). It’s poetic because of what it means.

Arthur Fleck, wearing his full-on Joker regalia for the first time (rust suit, orange vest, smeary clown make-up, green hair), turns his face toward the sky as if smiling at a higher power. It’s a moment of worship; his posture and gaze are ecstatic. But it’s also as pure an image of a madman as Leatherface twirling his chainsaw in the dawn light at the end of “The Texas Chain Saw Massacre.” Arthur is one sick puppy, a geek who uses fake laughter and fake smiles to conceal his unfathomable despair (and to billboard it too, since the fakery is so over-the-top that he’s really saying, I know this isn’t fooling you). But now, at this righteous moment, a current is running through him, something that has jolted him awake. With his face turned upward, he seems to be receiving a life force from above. He has embraced the dark side and seen the light. He has touched the liberating power of his hate.

No wonder he’s the antihero of the greatest American comic-book film in years, as well as the movie that has struck the richest and most unsettling popular chord of 2019.

Movies have always shown us who we are, but that doesn’t mean that dynamic has to be literal. I’m not the gunslinging hero of a Western, or the striving mistress of a plantation called Tara, or a motorcycle-riding rebel without a cause, or a New York street hustler who thinks he’s a cowboy, or Malcolm X or Fanny Brice or Truman Capote, or a skywalker in a galaxy far, far away, or a vigilante who comes out at night in a bat costume. But when I watch those movies, I’m each of those people. That’s the glory of cinema. And when I watch “Joker,” with the squirmy intimacy it establishes between the audience and Arthur Fleck, for two hours I’m a desperate mentally ill nowhere man looking for an escape hatch.

Arthur’s escape hatch is violence. He discovers who he is — or who he can be — when he’s attacked in public, and instead of cowering and taking it (the way he usually would), a force within him decides that he has to fight back. On that subway train, as three Wall Street louts taunt him and start kicking the crap out of him, he reaches for the pistol he’s carrying and shoots. At the end of his killing spree, all three are dead. It’s the sort of sequence we’ve seen in a thousand movies, from “Death Wish” on. In the Hollywood cinema of the last half century, a vengeful angry man dispatching scum with a gun is nothing new.

What’s new is what Arthur does after that. He ducks into a grungy public bathroom and does…a dance. A slow, ethereal one that begins almost as an instinct. When I first saw the movie, it looked to me like tai chi — a moment of creepy holistic bliss. Arthur has just committed a murderous crime, yet for the first time in his life he’s serene. His turmoil is stilled; he has found liberation and release. The declaration of his hate has healed him. This, you could say, is true of countless movie villains, from mobsters to James Bond megalomaniacs; violence makes them come alive. But Arthur is at once the villain and protagonist of “Joker,” and the brilliance of Joaquin Phoenix’s performance — and the daring of the movie — is that Phoenix takes the psychological syndrome of feel-good rage and lays it bare, strips it naked, showing us Arthur from the inside, putting us in touch with the warped fury that has tormented him, and is now cleansing him.

When the film-critic establishment, or at least a major swatch of it, turned against “Joker,” the issues that were raised about whether the film was somehow “irresponsible” went beyond the raw question of whether it might end up inspiring an act of violence. The critics seemed to be saying: Whether or not it inspires violence, the film is speaking “for” incels — i.e., angry depressed white men who have nothing to do with us, the good progressive people, and so we resent the fact that the pathological incel brigade has been given its own blockbuster megaphone.

But that betrays a fundamental misunderstanding of how movies work. “Joker” isn’t a drama about one isolated, festering demographic of hatred in our society. Like all great pop fantasies, it’s a dream. It works by expressing something about all of us.

What it’s expressing is the inner tenor of a certain moment in time — in America, and maybe the world — when hate has begun to take over. The culprits seem obvious enough. A U.S. president who revels in any destruction he can cause, flaunting his lack of empathy, demonizing those who aren’t “normal” Americans. The followers who support and mimic whatever he does, as if they were part of a cult of white rage. (They are.) The currents of nationalist fury that are spreading, like a virus, through Europe.

But we know all that. Part of the karma of our time is the way anger has become symbiotic. Quite apart from the despicable agendas of right-wing rage, we’re at a moment when the lashing out of the kind of anger we used to associate with fire-breathing talk radio is becoming a universal addiction.

I’m in no way implying an “equivalence” between the seething intolerance expressed on a daily basis by Donald Trump, with his neo-fascist exhortations against the rule of law, and the liberal intolerance of Trumpism, which is wholly justified and necessary. My point is that America is fast becoming a dysfunctional family of mutually reinforced resentment. If you grow up reacting with bottomless rage against an abusive parent, that reaction is totally justified, but it still makes you a person full of rage. (That’s why people go to therapy.) If you live on social media, look at what our culture, including liberal culture, is becoming: a series of rants and gripes and feuds and takedowns, a kind of unending middle-class war over everything from the proper ways of motherhood to the ending of “Game of Thrones.”

As Arthur says in “Joker,” “Is it just me, or is it getting crazier out there?” As the basic security of the American middle class frays before our eyes, the primal anxiety is starting to tear at the fabric of people’s well-being. Yet even liberals can’t agree on the solutions. (Single payer? Looks good on paper, but politically it sounds to some of us like Trump’s ticket to the permanent presidency.) The only thing everyone seems to agree upon is how violently we disagree. We’re becoming the dis-united States, a volatile landscape charged with combustible aggression. What’s important to recognize, however, is that the anger at the center of this social-cultural-political entropy isn’t simply a destructive force. It has taken hold because in some desperate way, it’s a cathartic force. I rant, therefore I am. I snark and tweet (with a vengeance), therefore I am. I rage, therefore I am.

And part of what we should all be angry about is the fakery of our public discourse. Not just the fake news, but the real news that’s too devoted to stirring the pot (since that’s what’s profitable), the entertainment designed to numb us instead of enlighten us, and — yes — the social media that was supposed to embody a liberal ideal of “connection,” but that didn’t quite work out that way because even liberals spend so much time on it posturing and positioning (i.e., lying about who they are). All these layers of unreality are something a lone human animal instinctively wants to blast through. And that’s just what happens in the spectacular climax of “Joker.” Arthur turns toward the entertainment figure he has idolized as a surrogate daddy, and he says, “You’re awful.” And he’s right. It’s the fakery of it that’s awful. The fakery, in its way, is what Arthur wants to kill.

That’s why he’s more than just an “incel.” He’s all of us. All of our anger, all the rage that leaves us feeling so liberated when we let it out. Yet don’t take that too literally. Arthur is a figment, a projection, a dream image of our collective spirit. That’s why he’s a warning. “Joker” says: Smile when your heart is raging. And know that this is what it looks like.