With Great Books, I was trying to save myself,” David Denby says, leaning forward intensely from a chair in his Upper West Side living room. “With Lit Up, I’m trying to save what matters in the world.”

The former longtime New Yorker film critic’s description of the motives behind his first book and his most-recent book makes it clear just how seriously he takes literature. Denby doesn’t just think reading books is good for you; he believes it makes you a better citizen and a better person. Lit Up: One Reporter, Three Schools, Twenty-Four Books That Can Change Lives, which Henry Holt will publish in February, chronicles his experiences sitting in on 10th-grade English literature classes during the academic years 2011–2012 and 2013–2014. In the book, Denby shows passionate, dedicated teachers convincing teens usually glued to their electronics that reading Dostoyevski can give them insight into their own lives.

It’s a conviction Denby shares, eloquently stated with a somewhat different emphasis in his 1996 debut, Great Books: My Adventures with Homer, Rousseau, Woolf, and Other Indestructible Writers of the Western World. “The first book’s issue was sort of ideological,” he explains. “The Western classics were being mauled left and right, and I thought the reading experience had been lost and the actual nature of these books had been lost.” So Denby, who at the time felt that he spent too much of his life consuming images, went back to Columbia University, his alma mater, and retook its famous core humanities courses. Great Books conveys with refreshing enthusiasm and unpretentiousness the intellectual nourishment he found there. “It was a kind of reclamation job on myself,” he says.

By contrast, Denby says Lit Up “came from what seemed to me like a general reading crisis.” He adds: “It’s very hard to come by exact information, but anecdotally it definitely feels like kids are not reading very seriously. They may be reading more words than ever before, but they’re reading fragments online. We live in this media bubble; we’re constantly taking in information, but information is not the same thing as knowledge.”

As Lit Up recounts, Denby found that even the high-achieving, highly motivated students at Manhattan’s prestigious Beacon School tended at first to make simplistic judgments about their reading, finding neat parables and pat lessons in works as dark and ambiguous as Hawthorne’s story “The Minister’s Black Veil.” “I think Sean Leon [their teacher] made them see things in a more complicated way,” Denby says. Also, he continues with a wry smile, “Sean is a lapsed Catholic with very serious ideas about accountability and knowing yourself, so his emphases in class jibed perfectly with what 15-year-olds are going through: Where do I fit in? Who am I? What is the point?”

An equally inspired teacher named Jessica Zelenski had more basic work to do with her mostly low-income students at James Hillhouse High, an inner-city school in New Haven, Conn., Denby says. “A lot of the kids there had low skills and low information; they weren’t read to as kids, and they didn’t develop the habits of curiosity, hunger, avidity. They were enclosed in this narcissistic shell: ‘I know what I need to get by in my life.’ Jessica used To Kill a Mockingbird as a way to get them to ask questions: What did people eat in 1930s Alabama? How did they get around? She wanted to make them curious about what the frame of that world was, and therefore grasp what the frame of their own world is.”

Denby argues that “the humanities are not irrelevant; they’re highly relevant to a modern economy.” He adds: “Big-scale employers keep saying, ‘We can teach you the computer or technical skills we need you to know in six or eight weeks. We want people who have judgment, people who can stand up in a meeting and talk, who can work with others and understand their coworkers.’ That comes from the attentiveness and roundedness and strength you get from reading seriously. We’re not just denaturing education and literacy with this emphasis on STEM [Science, Technology, Engineering, and Math] subjects, we’re making a mistake in the kind of work force we’re readying.”

That said, Denby cares most about literature as a spiritual, moral, and even political force. “We live in a country in which, at the moment, ignorance is highly prized,” he says ruefully. “Despite the amazing superfluity of information, an amazing number of people are only hearing what they already want to hear. If you have lifetime habits of curiosity and are reading deeply, you’re going to escape that—I hope. I’ll put it tendentiously: if more people had read Dickens and Twain, could Donald Trump be taken seriously for more than 10 minutes? A certain kind of phoniness would be obvious to anyone who knows Huckleberry Finn.”

Denby is an earnest man, albeit with a streak of self-deprecating humor, and his apartment’s crammed bookshelves suggest that he practices the sort of reading he preaches. His wife, Susan Rieger, a Yale dean recently turned novelist with The Divorce Papers, has a desk in their bedroom. Denby’s working space is presumably downtown at the New Yorker, though he gave up his half-share of the magazine’s movie column a year ago. “David Remnick [editor-in-chief] said, ‘Maybe this is enough, and you should write something else,’ ” Denby explains. “He didn’t think I was failing as a critic, but he didn’t think he could afford two movie critics anymore, and I didn’t argue.”

Do the Movies Have a Future? (2012) expresses Denby’s disenchantment with an industry increasingly devoted to big-budget special effects blockbusters. “I haven’t given up on movies as an art form, but it’s not a great period,” he says. “I’m gearing up to write other things for the New Yorker now that the book is finished, and I’m writing for the Library of America online about the adaptation of Washington Square by Henry James into The Heiress, a terrific 1940s movie.”

Denby’s also thinking about his next book, though he’s reluctant to give specifics while his ideas are still being formed. Now 72, with five books on his résumé, he doesn’t plan to retire anytime soon. “You can’t write unless you’re obsessed, and I tend to have serial obsessions,” he says. “So I write a book about losing money during the tech boom [American Sucker, 2004] or about uncivilized discourse [Snark, 2009]; an obsession produces a book. You get up with it every morning and go to bed with it every night. You keep a pad next to the bed so when you wake up in the middle of the night you can write things down, or a pad inside your jacket so when you’re at dinner you can pull it out, and suddenly you’re not part of the conversation anymore. It’s a state of blessedness, in the sense that you’re lucky to do it, and a state of illness, because you’re not a normal person.”

It’s all worth it, Denby concludes, “when you finally hold the finished copy in your hand.” He says, “E-readers are a great convenience, particularly when you travel, but I love the heft and feel of a book, running your fingers backward and forward in it, saying, ‘This is mine, a little piece of my soul.’ ”