This, apparently, is “normal” in the United States: Earlier this week, in the small town of Benton, Kentucky, a high school sophomore walked onto his campus and started shooting, wounding several schoolmates and killing two — Bailey Nicole Holt, who died at the scene, and Preston Ryan Cope, who died after he was transported to a hospital. Americans barely noticed.

It was the 11th school shooting of this year (and this month), according to the New York Times. (Some were suicides; some resulted in no injuries.) As Katherine W. Schweit, a former FBI official and an expert on school shootings, put it: “We have absolutely become numb to these kinds of shootings.”

There is no other country on the planet that tolerates gun violence as we do. We have about 5 percent of the world’s population, but we account for 31 percent of the world’s mass shootings. Between 1966 and 2012, there were 90 mass shootings in the United States, according to University of Alabama professor Adam Lankford, who has published a study about shootings that kill four or more victims. We also rank No. 1 in gun ownership; in a nation of 317 million people, there are about 357 million guns. As Lankford notes, there is a connection between that staggering number of guns and the number of people who die as a result of gun violence.

“For decades, people have wondered if the dark side of American exceptionalism is a cultural propensity for violence,” he wrote, “and in recent years, perhaps no form of violence is seen as more uniquely American than public mass shootings.”

His study did not include the October 2017 horror in Las Vegas, where gunman Stephen Paddock fired into a crowd of unsuspecting concertgoers, killing 58 and injuring countless others. These atrocities, if they are awful enough, capture our attention for a week or so. The Benton shooting hardly induced a raised eyebrow. Such is our capacity for denial, for resignation, for apathy.

Polls show that most Americans favor stricter gun laws, but Congress has failed to pass any. The gun lobby holds Congress hostage, refusing to sanction even the mildest restrictions. The National Rifle Association believes that any man, woman or child should be able to buy his or her own shoulder-fired grenade launcher, and the American public doesn’t care enough to fight against that nonsense. If the 2012 massacre of babies at Sandy Hook Elementary School didn’t change us, what will?

Some blame our renowned founding document, the U.S. Constitution, which includes a Second Amendment that explicitly states, “A well-regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed.” But you cannot read that sentence and ignore its opening clause, which sets its context.

The amendment was meant to protect a citizens’ militia, such as the National Guard, not individuals. In recent years, federal courts have grossly distorted its meaning. In prior generations, jurists agreed that it did not protect the right of individuals to own any weapon they wanted.

Indeed, much about gun culture has changed since my childhood. I grew up in the Deep South — rural Alabama — with a father who loved hunting and who owned firearms. He was typical of his time and place; he hunted with brothers, brothers-in-law, and friends. But my father was strict about gun safety, and he would not have recognized a culture that allows worshippers strapped with holsters to take their guns into church. An educator, he would have been aghast at a gun lobby that insists that teachers should be able to carry their guns into the classroom.

Some blame our frontier heritage for our fondness for firearms. Yet, Australia has a similar frontier heritage — cowboys, ranches, endless prairies — and that nation got a grip on gun violence. After a mass shooting in 1996 that left 35 people dead, Australia’s then-prime minister, John Howard, pushed through a set of strict gun laws and instituted a gun buyback program. In the years that followed, gun deaths plummeted.

We seem incapable of that sort of rational thinking. We are caught up in a uniquely American form of madness, suffering a sort of paralysis that has normalized the unthinkable.