I went to a matinee of “The Book of Mormon” over the weekend, and — I promise these things are connected, read on — when I came back from the city, late in the evening, I found just about everyone I follow on Twitter making sport of this foray from Joyce Carol Oates:

All we hear of ISIS is puritanical & punitive; is there nothing celebratory & joyous? Or is query naive? — Joyce Carol Oates (@JoyceCarolOates) November 22, 2015

Now I get where the snark was coming from, I really do. (Especially given Oates’s rather, ah, entertaining Twitter history.) “All we hear about the Khmer Rouge is the massacres, the re-education camps, the piles of skulls; was there nothing celebratory in beginning society anew, with fewer intellectuals and bespectacled people?” “All anyone talks about with the Salem Witch Trials is the paranoia and fear and killing; was there nothing joyous about gathering as a community for a hanging?” You can play this game all day.

And yet: If you don’t recognize that for at least some of the Islamic State’s young volunteers there is a feeling of joy and celebration involved in joining up, then you’re a very long way from understanding the caliphate’s remarkable appeal. And Oates, in a daffy-seeming way, has put her finger on one of the West’s weaknesses in this conflict: Our widespread inability (concentrated in particular among our leadership class) to imagine or understand what else, beyond the pull of sadism and thuggery, our fellow human beings (including quite a few young, Western-raised people) seem to find intoxicating about the Daesh experiment.

Via Rod Dreher, who’s been writing a great deal on this theme, here’s an excerpt from a New York Review of Books piece by Scott Atran and Nafees Hamid, discussing the, yes, joyous and celebratory feelings that the Islamic state’s religious utopianism instills in people cut adrift by secular modernity:

France’s Center for the Prevention of Sectarian Drift Related to Islam (CPDSI) estimates that 90 percent of French citizens who have radical Islamist beliefs have French grandparents and 80 percent come from non-religious families. In fact, most Europeans who are drawn into jihad are “born again” into radical religion by their social peers. In France, and in Europe more generally, more than three of every four recruits join the Islamic State together with friends, while only one in five do so with family members and very few through direct recruitment by strangers. Many of these young people identify with neither the country their parents come from nor the country in which they live. Other identities are weak and non-motivating. One woman in the Paris suburb of Clichy-sous-Bois described her conversion as being like that of a transgender person who opts out of the gender assigned at birth: “I was like a Muslim trapped in a Christian body,” she said. She believed she was only able to live fully as a Muslim with dignity in the Islamic State. For others who have struggled to find meaning in their lives, ISIS is a thrilling cause and call to action that promises glory and esteem in the eyes of friends, and through friends, eternal respect and remembrance in the wider world that many of them will never live to enjoy …

And here are the same authors on the gap between this vivid conversion experience and the feeble Western attempts to talk ISIS recruits out of their newfound cause:

In its feckless “Think Again Turn Away” social media program, the US State Department has tried to dissuade youth with mostly negative anonymous messaging. “So DAESH wants to build a future, well is beheading a future you want, or someone controlling details of your diet and dress?” Can anyone not know that already? Does it really matter to those drawn to the cause despite, or even because of, such things? As one teenage girl from a Chicago suburb retorted to FBI agents who stopped her from flying to Syria: “Well, what about the barrel bombings that kill thousands? Maybe if the beheading helps to stop that.” And for some, strict obedience provides freedom from uncertainty about what a good person is to do. By contrast, the Islamic State may spend hundreds of hours trying to enlist single individuals and groups of friends, empathizing instead of lecturing …

The deep reality here (a reality not unlike the one that’s playing itself out on certain college campuses right now) is that many human beings, especially perhaps young human beings, still crave a transcendent purpose, even in a society that tells them they don’t really need one to live a comfortable, fulfilling life. And more than that, many people experience both a kind of liberation and a kind of joy in submission to these purposes, even — as is the case with ISIS — when that submission involves accepting forms of violence and cruelty that rightly shock the conscience of the world.

This joy is not something that our culture is conditioned to expect or accept, let alone to counter. I promised to bring this back around to “The Book of Mormon,” so here goes (with spoilers): Despite being the work of two of American popular culture’s most scabrous and deliberately un-P.C. provocateurs, Matt Stone and Trey Parker, the musical is remarkable for the deep conventionality of the religious story that it tells. That is, “Mormon” features a narrative in which the young L.D.S. missionaries are well-meaning guys straitjacketed by their religious culture’s vision of transcendence — the fear of hell it inspires, the repressive moral code it imposes, the implausible things it makes them believe in order to hope for everlasting life. But then they (with an assist from their African converts) realize that the real point of religious stories is just to help you be kind and happy and public-spirited, that it doesn’t really matter if they’re true, and the result is liberating, freeing, joyful:

What happens when we’re dead?

We shouldn’t think that far ahead

The only latter day that matters is tomorrow. … We love to dance and shout

and let all the feelings out

and work to make a better latter day …

John Lennon couldn’t have put it any better. And my distaste for “Imagine” notwithstanding, the joy involved in making this shift is perfectly real! Where traditional religious authorities crush the human spirit, the escape into either more liberal forms of faith (the “Book of Mormon” move) or straightforward secular humanism is very naturally felt as a blessed renewal, an ecstatic release. This feeling isn’t something made-up by a few godless liberals: Large parts of our culture lived through it in the 1960s, and people who grow up in particularly suffocating religious atmospheres can still experience it today — which is why the story retains so much power as a Western master narrative, why even men like the “South Park” guys, to whom little is sacred, rely on it to lend a moral arc to their cheerful blasphemies.

But as Philip Larkin knew early, the “long slide to happiness, endlessly” that allegedly awaits when you drop the old religious scruples often has something else waiting at the bottom, and the reality of death can be put off till a latter day, till tomorrow and tomorrow, and tomorrow …, but never entirely denied. “We love to dance and shout / and let all the feelings out, / and work to make a better latter day” … that’s a way to live, certainly, but it leaves some pretty big human concerns under-addressed, and when that “better latter day” isn’t all you hoped for fears creep in around the edges, and maybe you respond to them by injecting a little more utopianism into your secular liberalism … or maybe you’re a little more lost than that, a little more desperate, a little more existentially-adrift, and you make some new friends online who believe that God actually has a plan for you, that you aren’t just a mote floating randomly in sunlight streaming through high windows, that the eye that’s on the sparrow is on you as well, and if there’s a price to be paid for that belief, a price in blood and even savagery, well doesn’t everything worth anything come with a price?

“Nothing costs enough here,” Huxley’s Savage complains about the brave new world. If ISIS costs, a certain meaning-starved cohort in our world thinks, maybe that just means it’s real.

That cohort is still mercifully small, and unless radical Islam acquires a lot more intellectual cachet it’s likely to remain so. But if the West’s official alternative to ISIS is the full Belgium (basically good food + bureaucracy + euthanasia), if Western society seems like it’s closed most of the paths that human beings have traditionally followed to find transcendence, if Western culture loses the ability to even imagine the joy that comes with full commitment, and not just the remissive joy of sloughing commitments off — well, then we’re going to be supplying at least some recruits to groups like ISIS for a very long to come.

A last “Book of Mormon”-related thought: As it happens, I’ve visited the Mormon missionary center where the musical opens, as part of a larger excursion to Salt Lake City and Provo a few years ago. Seen through Catholic eyes, not secular ones, it’s a place and a culture that’s at once extraordinarily impressive and somewhat strange and stifling; you can understand why so many Mormons commit to it absolutely and also why a certain percentage flee it with relief.

But whether you’re looking at Mormonism or any other intensely-lived-out faith, you have to see both of those realities. Because if you build your entire worldview and assumptions, as too many of our cultural institutions and “thought leaders” have, around just the second half of that equation, then your understanding of your fellow human beings — and your ability to speak to some of them in extremis — will be tragically incomplete. If you can’t see — as “The Book of Mormon,” while generous in certain ways to its subjects, doesn’t really see or convey — that there’s more authentic, Joyce Carol Oates-ian joy in fervent conservative religious practice and belief than there is in many allegedly-enlightened swaths of our society (including certain “enlightened” Catholic theology departments, if I might offer a just-slightly uncharitable example), then the past and future alike are going to be mysterious to you, and so are certain very important things happening right now.

Where the brighter joy of Mormons is invisible, in other words, the dark joy of ISIS will be entirely incomprehensible. That lack of comprehension isn’t Islamic radicalism’s only weapon. But it’s a useful one for the caliphate to have ready to its hand.