Umberto Eco in 2010. (Luca Bruno/AP)

In his essay “Lumbar Thought,” Umberto Eco, who died last week at 84, worried that blue jeans limit our capacity for thought. He wasn’t objecting to the garments themselves. He wrote that he loved the comfort of denim, not least of all because there were “no problems of creases, tearing, spots.” The real issue, he claimed, was that the very ease of wearing his jeans — along with their firm grasp on his crotch — called his attention to his own body. This second skin left him focused on exteriors, distracting him from his normally busy inner world.

Eco’s deep fascination with the mundane things that shape our lives was one of his defining features. Best known to most for his novels, he also produced volumes of abstruse critical theory, along with numerous shorter essays like “Lumbar Thought.” Though there have always been figures who bridged the gap between academia and public discourse, few have done so with such self-evident pleasure as Eco. That contagious joy clearly followed from the delight he took in culture itself, the vital variety of its forms and forces fitting him better than the tightest pants.

Look, for example, at the things he claims he thought about when freed from the compressive armor of his jeans. In “Lumbar Thought,” he lists a few: “the relationship between the One and the Many, the Andreoiti government, how to deal with the problem of the Redemption, whether there is life on Mars, the latest song of Celentano, the paradox of Epimenides.” Here pop music presses up against classical philosophy, even as scientific curiosity collides with theological speculation. If Eco became a cultural figure in his own right, it may have been because he always worked in these varied registers, unapologetically muddling high and the low culture into unexpected cocktails.

Writing on Superman comics, Eco spoke of the “oneiric climate” in which the stories played out. There was, he held, something dreamlike about these tales, tales whose narratives tangoed between chaotic indeterminacy and stable familiarity. On the one hand, anything could happen to Superman in a given issue: He might find himself in another galaxy or travel back in time. But on the other hand, certain things would always stay the same, certain features of the character and his world always maintaining a satisfying normalcy. Eco’s work shared some of this quality, comforting precisely because it was profligate, constant in its inconstancy.

Even when he was skeptical of his critical targets—as he arguably was of Superman—Eco maintained a bemused generosity, never encountering a bit of cultural content that didn’t charm him. In 1963, long before other academics began to write about comics, he discussed the power of “Peanuts.” Where some might have dismissed the strip for its popularity—or simply drilled down into its intellectual resonances—he lovingly examined the sources of its widespread appeal. Describing it as “a little human comedy for the innocent reader and for the sophisticated” alike, he analyzed the patterns that made it accessible to so many in so many different ways.

Eco wasn’t, of course, exceptional in his openness to whatever might come. Many of his contemporaries—perhaps most notably Roland Barthes, who memorably analyzed Einstein’s brain and Garbo’s face in Mythologies—exhibited a similar comfort with the interplay of cultural forms. But where Barthes was frequently evasive, Eco was consistently present, clearly happy to participate in the culture he was considering. In this regard, he helped pave the way for later generations of public intellectuals. He had less in common with Harold Bloom or Judith Butler than with the likes of the Pulitzer Prize-winning Ta-Nehisi Coates—who will be scripting Marvel’s “Black Panther“—or the New Republic’s Jeet Heer—who’s written on the comics of Chris Ware and helped popularize the Twitter essay.

Eco doesn’t just stand out for his intellectual openness, though: He’s also remarkable because he analyzed the idea of openness itself. Early in his career, Eco’s scholarship focused on the idea of the opera aperta, the “open work.” He was interested in texts that seemed to invite interpretation, studying how and why some were more easily subject to the whims of readers than others. This preoccupation continued throughout the decades that followed, especially in volumes such as “Six Walks in the Fictional Woods,” which contemplates the relationship of model readers—those impossible creatures who follow the exact instructions that a text lays out—to empirical ones who bring their own preoccupations to the page.

Eco’s curiosity about the way about the way we read may have been his undoing, at least for his academic audience. The literary critic and theorist Jonathan Culler (one of my PhD advisors), who memorably argues with Eco in “Interpretation and Overinterpretation,” suggested as much to me in a recent phone call. “The eclipse of his work goes along with the eclipse of reader response criticism,” Culler suggested, referring to a theoretical movement more typically associated with Stanley Fish. That, at any rate, may help explain why most of the articles written in Eco’s honor this week avoid his more philosophical inquiries. Most at least allude to his interest in semiotics, but few dwell on his contributions to the field, a testament to the way his academic profile sank in the U.S. academy while his broader cultural stature grew.

But Eco’s thought never vanished completely from public view. If anything, it grew more diverse and accessible, never losing its incisive edge. He was also, by most accounts, profoundly charming. Culler told me that he still remembers feeling envious of Eco after bringing the rising Italian star to give a talk at Cornell decades ago. “He was this big bear of a man,” Culler said. “With that accent he could say anything—even ‘I am glad to be here’—and get a laugh.” A similarly genial quality resonates out of virtually everything Eco published, from his all too brief final novel, “Numero Zero,” to difficult philosophical studies like “Kant and the Platypus.” Available to all, he himself was an open work come to life, the opera aperta incarnate.

Joyously munificent, Eco is like a proof of concept for contemporary intellectual culture, one who thought in public as he moved fluidly between worlds. For most, of course, it’s Eco the novelist that will always be remembered best, another fact that likely does him no favors in the academy. And if he’s known as a novelist, he’s sometimes known as one far more widely purchased than read. “Name of the Rose”—with its jokes in untranslated Latin, its discussions of lost Aristotelean treatises, and its winking references to medieval monkish traditions—might be laughed off as the kind of book that’s meant to show you are a thinker, not as an invitation to thought.

Reading “The Name of the Rose” for the first time in my teens, however, I was struck most of all by how much fun Eco himself seemed to be having. I didn’t understand half of it, but I loved the way he mashed up mystery topes and historical facts, never privileging the one over the other. I finished it over spring break while visiting my father in Ohio, listening to a thunderstorm build as I made my way through its final pages. Turning off the lights and closing the book, I found myself thinking that I’d like to meet the bearded professor pictured on its “about the author” page, that I’d like to keep learning from him. And then, while I dozed off, preparing to dream of murderous monks, something happened that I’ve never experienced since: A lightning bolt flashed so brightly that I could see every detail of the room, even with my eyes closed.

I didn’t know it at the time, but I’d learn it in the years to come: That was Eco, a burst of light so brilliant that you couldn’t help but see the whole world more clearly, whether or not you were looking.