By 1971, he had been named the Book Review’s editor in chief — “through a series of accidents, deaths,” he says. He turned it into a provocative and combative section that many still think represents a high point in the publication’s history. On the cover, he put reviews of daring novels by relative unknowns (like End Zone, Don DeLillo’s second novel), and he published thoughtful reviews of the literature of debate surrounding the Vietnam War. After he stepped down, in 1975, he began reviewing books as a daily critic for the Times, and, later, movies and TV for other venues, including CBS Sunday Morning and New York. Although he has written widely on popular culture, he considers literary criticism to be his true vocation. “I love pop culture. I reviewed TV for decades and got a kick out of it, but nobody is going to tell me that there are deeper abiding complexities and discomfitures than those I find in great literature,” he says. And it is in his literary criticism that the outlines of a powerful life of the mind truly take shape.

Leonard has published six essay collections — This Pen for Hire (1973), Private Lives in the Imperial City (1979), The Last Innocent White Man in America (1993), Smoke and Mirrors (1997), When the Kissing Had to Stop (1999), and Lonesome Rangers (2002) — and to read any one of them is to be struck by how the pieces speak to one another. A Leonard collection is not a miscellany. From the start, his work has expressed powerful ambivalences about inherited systems of thinking. His main strength, as a reader of fiction and literary nonfiction, is the way he complicates what are often framed as zero-sum debates. Among his best writing in recent years is an essay on Primo Levi that scrutinizes the assumption of some critics — the novelist Cynthia Ozick among them — that Levi was too forgiving of the Holocaust, too willing to put his hatred and damage aside. For those critics, Levi’s final book, The Drowned and the Saved, in which he writes about the horrors of camp prisoners’ collaborating with Nazis to avoid being exterminated, marks an ascent to form because it finally unleashes Levi’s rage and hate. But for Leonard, it is a further tragedy, the manifestation of the encroaching unbalance that led Levi, finally, to kill himself. The earlier Levi, he suggests, “argues that perhaps something of the best of us, skeptical, ironic and aware, could outlive the worst.” Why wish for those who bring us news from horror to have no sense of forgiveness?

If the primary mode of literary criticism is exposition, Leonard’s method tends to be immersion. His reviews rarely treat a single book by the author at hand; rather, he gathers together a mass of textual and biographical materials. In his essays on Saul Bellow, Bruce Chatwin, Ralph Ellison, Bernard Malamud, Bob Dylan, and, more recently, Jonathan Lethem, Rick Moody, and Jonathan Franzen, he peers closely at “those masks, sacred and profane, that the artist wears while digging up the buried bodies and playing with the bones.” Instead of merely analyzing a book, he brings to life an entire literary sensibility, warts and all, animating each writer’s larger outlook.

Leonard himself has a novelist’s knack for memorable characterization. He has called Edmund Wilson “an alcoholic minotaur,” and has described Joan Didion as a journalist writing “gnomic haikus” while “wearing a bikini and a migraine to every convulsion of the post-war culture.” Leonard is also a connoisseur of the aphorism. From a 1981 essay on literary status: “A curmudgeon is different from a snob. A snob can be disdainful in only one direction; a curmudgeon spreads his contumely around.” From a 1977 essay on literature about businessmen: “Kafka looked in the mirror and saw the modern corporation.” At times, he is diverted by insider punning and overly dense allusions — too much so, for example, in the opening of “Knee-Deep in the Alien Corn,” an essay from When the Kissing Had to Stop, in which he writes, “Forget Seinfeld — a cheese doodle of urban fecklessness in which, to every penis joke, the white bread slackers wore a prophylactic smirk.” Still, his wordplay is often illuminating and enlivening. It reminds us there are as many ways of talking about literature as there are of writing a short story.

Meghan O’Rourke is the culture editor of Slate.