Peggy Noonan

At a screening of "The Dark Knight Rises" the other day on Manhattan's East 86th Street, three cops were posted outside, two in a cruiser and one on a motorcycle. An usher said they'd been coming by since the shooting in Aurora, Colo. She was relieved they were there; we now can add movie ushers to the list of those who hold hazardous jobs in America. But you wish Hollywood and not the taxpayer were paying for it.

The people in the theater were jumpy, getting up and going out the exit, coming back. The movie itself is dark -- murders, massacres, torture, weird sinister chanting, foreboding music. There's some sort of revolt, and Gotham is taken over by a small army led by a monster. They shoot up the floor of the stock exchange. The homes of the wealthy are ransacked. The thinking or motivation of the monster-leader, Bane, is never made clear.

"No one cared who I was till I put on a mask," he says, in one of the lines that seemed to prefigure the Aurora perpetrator.

Did "The Dark Knight Rises" cause the Aurora shootings? No, of course not. One movie doesn't have that kind of power, and we don't even know if the shooter had seen it. But a million violent movies have the cumulative power to desensitize and destabilize, to make things worse, and that's what we've been seeing the past quarter century or so, the million movies. Each ups the ante in terms of carnage. Remember Jack Nicholson's Joker, from 1989? He was a garish, comic figure and he made people laugh. He was a little like Cyril Ritchard as Captain Hook in the old TV version of "Peter Pan." You knew he wasn't "real." He was meant to amuse.

Compare that with Heath Ledger's Joker in 2008's "The Dark Night." That Joker was pure evil, howling and demonic, frightening to see and hear. If you know what darkness is, you couldn't watch that Joker and not be afraid. He looked like the man who opens the door when you get off the elevator to enter Hell; he looked like the guy holding the red velvet rope. That character was so dark, and so powerful, he destabilized the gifted actor who played him. Ledger died of a drug overdose six months before the movie opened.

About 15 years ago, a TV interviewer noted my concern at the damage I thought was being done by the highly violent, highly sexualized nature of our culture, of our movies and TV and music. It will make us more brutish, I'd argued, and some will imitate what they see.

The interviewer was good-humored but skeptical: Hollywood makes a lot of comedies. Why don't we see the country breaking out in laughter?

Violence is different, I said, because there are unstable people among us, and they are less defended against dark cultural messages. The borders of the minds of the unstable are more porous. They let the darkness in. You can go to a horror movie and be entertained or amused: "This is scary, I love getting scared, and I love it because I know it isn't real." But the unstable are not entertained by darkness. They let it in. They are inspired by it. Sometimes they start to live in the movie in their heads. "I am the Joker," the shooter is reported to have told the Aurora police.

Carl Cannon, in a thoughtful, deeply researched series on RealClearPolitics, this week gave a measured, tempered look at our entertainment culture and its role in the Aurora shootings: "A hundred studies have demonstrated conclusively that viewing violence on the screen increases aggression in those who watch it, particularly children." Ignoring the problem hasn't made it go away. He quoted Jenny McCartney of London's Daily Telegraph, after she had seen 2008's "The Dark Knight": "The greatest surprise of all -- even for me, after eight years working as a film critic -- has been the sustained level of intensely sadistic brutality throughout the film." The movie begins with a heist by men in sinister clown masks. "As each clown completes a task, another shoots him point blank in the head. The scene ends with a clown -- the Joker -- stuffing a bomb into a wounded bank employee's mouth."

What effect might a scene like that have on a man who is mentally or emotionally ill and beginning to have violent fantasies?

Mr. Cannon noted the different ways Hollywood executives have attempted to rationalize and defend what they produce. At first they claimed TV and movies had no impact on the actions of viewers. Then why, they were asked, have commercials, and why have characters who don't smoke? Next filmmakers claimed violent movies not only don't increase violence, they probably decrease it by letting audiences vicariously blow off steam. "Legions of social scientists lined up to test" the catharsis theory, says Mr. Cannon. They discovered the opposite: "Violent programming desensitized young people to violence, made them more likely to hit other children, and often engendered copy-cat behavior."

Some of the sadness and frustration following Aurora has to do with the fact that no one thinks anyone can, or will, do anything to make our culture better. The film industry isn't going to change, the genie is long out of the bottle. The genie has a cabana at the pool at the Beverly Hills Hotel. The movie market is increasingly international, and a major component is teenage boys and young men who want to see things explode, who want to see violence and sex. Political pressure has never worked. Politicians have been burned, and people who've started organizations have been spoofed and spurned as Puritans. When Tipper Gore came forward in 1985, as a responsible citizen protesting obscene rap lyrics, her senator husband felt he had to apologize to Democratic fund-raisers. If some dumb Republican congressman had a hearing to grill some filmmakers, it would look like the McCarthy hearings. There would be speeches about artistic freedom, and someone would have clever words about how Shakespeare, too, used violence. "Have you ever seen 'Coriolanus?'"

The president won't say anything -- he too is Hollywood funded -- and maybe that's just as well, since he never seems sincere about anything anymore.

A particularly devilish injustice is that many of the wealthy men and women of the filmmaking industry go to great lengths to protect their own children from the products they make. They're able to have responsible nannies and tutors and private coaches and private lessons. They keep the kids busy. They don't want them watching that garbage.

Everyone else's kids?

One thing about good parents these days is they always look tired. A lot have hard lives -- two jobs, different shifts, helping with homework, cleaning the house. But they also have the exhausted look of hyper vigilance.

Once parents could take a break at night, park the kids in front of the TV and let the culture baby-sit. Not anymore. Our culture, they know, is their foe. The culture brings sick into the room. They have to guard against it, be hypervigilant: "Put that off!" "I don't care if your friends are going, we're not."

It's a wonder they don't revolt.