It is all their fault, really.

You know who. Those good-looking young women who turned Elliot Rodger down. All he wanted was to live a happy life, if only they would let him. But they spurned him, again and again, because they were "incapable of seeing the value" in him. And so he struck a "devastating blow" that shook them "to the core of their wicked hearts."

You and I do not think like that, fortunately. We can see Rodger's sick, twisted thinking for what it truly was: a demented delusion, inspired by the unhealthy culture in which he was steeped.

As Washington Post film critic Ann Hornaday notes, Rodger grew up in the Hollywood entertainment industry, with its "outsize frat-boy fantasies" and a "sexist movie monoculture" that is "toxic for men and women alike."

Granted, Hollywood does not bear the blame alone. As the conservative periodical Human Events points out, Rodger also grew up in a broader culture—America—that instills in people an attitude of extreme "entitlement" without the leavening modesty of religious faith, which has been pushed to the margins.

What's more, as the liberal periodical Salon observed in "White Guy Killer Syndrome," Rodger was a white male—like so many other spree killers—and he plainly was frustrated by his "failure to . . . access all the markers of white male heterosexual middle-class privilege." To Ken Blackwell of the conservative Family Research Council, the cultural cause behind Rodger's rampage was the campaign for gay marriage.

Others deserving of some blame include the men's-rights movement and, of course, people who support gun rights.

Spree killers are often haunted by inner demons only they can hear. But those of us who pay close attention to the tidal movements of history can, with sufficient reflection, tease out their true motives.

After the 2012, massacre at Sandy Hook Elementary School, the National Rifle Association searched its soul and astutely concluded that the real problem was “a callous, corrupt and corrupting shadow industry” that promotes violence: video games.

After Jared Loughner's 2011 shooting rampage in Tucson, Arizona, The New York Times astutely observed that while it might be "facile" to attribute his deeds "directly to Republicans or Tea Party members," nevertheless it was "legitimate to hold Republicans and particularly their most virulent supporters in the media responsible for the gale of anger that has produced the vast majority of these threats." Conservatives, the newspaper correctly noted, "have exploited the arguments of division." Those people always do.

But not just conservatives. In 2009 Nidal Hasan massacred 13 people and wounded 32 others at Fort Hood. Federal authorities referred to the incident merely as "workplace violence." But we know better. We know it was an act of terrorism, perpetrated by a Muslim who divided people into two types: those who shared his vision of the world and those who did not.

Muslims and their liberal sympathizers might like to pretend that Islam is not the root cause of so many of the terrorist attacks on the American homeland, but the truth is obvious to the rest of us. The world would be a safer place if there were more like us and less like them.

Which is not to say that Islam is the only cause of terrorism. It has been less than two decades since Timothy McVeigh bombed the Alfred P. Murrah federal building in Oklahoma City, killing 168 people and injuring nearly 700. That is why we should be grateful that federal agencies such as the Department of Homeland Security, and independent groups such as the Southern Poverty Law Center, keep a sharp watch out for any sign of right-wing extremism.

Although to be fair, right-wingers do not have a monopoly on political violence either. During the Bush administration, Homeland Security paid close attention to the threat posed by radical environmental organizations such as the Earth Liberation Front, which set fire to many ski lodges in Vail and which the FBI identified as a leading cause of domestic terrorism.

Radical environmental ideas have inspired other episodes of violence as well. In 1995 newspapers acceded to demands by Ted Kaczynski (the Unabomber) by publishing his manifesto, which argued that "the Industrial Revolution and its consequences have been a disaster for the human race." Conservatives quickly made a parlor game out of guessing whether various statements had been made by Kaczynski or by Democratic Vice President Al Gore. It was often hard to tell, which only proves that people who worry about climate change are just like Ted Kaczynski.

People like that—people who do not think like us—are beyond the reach of rational argument. But despite their diverse ideologies, they all have one thing in common: They draw an invisible line separating themselves from the rest of us. Then they judge us, and then they pronounce sentence. They think they are striking a blow at our wicked hearts, but in their lack of self-awareness they cannot see their hearts are the ones that are truly wicked.

Thank goodness we don't think like that. All we want is to live a happy life, if only they would let us. But they never do.

It is all their fault, really.