In the nineteen-nineties, when you bought a book at Barnes & Noble the cashier slipped it into a plastic bag bearing a black-and-white illustration of an author’s face—Mark Twain, Oscar Wilde, Edith Wharton. Recently, I was poking around a bookstore in Manhattan and noticed a canvas tote for sale. In a simple red heart, the word “books” was spelled out in white letters. This tale of two bags is the story of decades of change in the publishing industry. “Books,” O.K.—but which ones?

The number of Americans who read books has been declining for thirty years, and those who do read have become proud of, even a bit overidentified with, the enterprise. Alongside the tote bags you can find T-shirts, magnets, and buttons emblazoned with covers of classic novels; the Web site Etsy sells tights printed with poems by Emily Dickinson. A spread in The Paris Review featured literature-inspired paint-chip colors (a charcoal Funeral Suit for “The Loser_”_; a mossy “Graham Greene”). The merchandising of reading has a curiously undifferentiated flavor, as if what you read mattered less than that you read. In this climate of embattled bibliophilia, a new subgenre of books about books has emerged, a mix of literary criticism, autobiography, self-help, and immersion journalism: authors undertake reading stunts to prove that reading—anything—still matters.

“I thought of my adventure as Off-Road or Extreme Reading,” Phyllis Rose writes in “The Shelf: From LEQ to LES,” the latest stunt book, in which she reads through a more or less random shelf of library books. She compares her voyage to Ernest Shackleton’s explorations in the Antarctic.__ “However, I like to sleep under a quilt with my head on a goose down pillow,” she writes. “So I would read my way into the unknown—into the pathless wastes, into thin air, with no reviews, no best-seller lists, no college curricula, no National Book Awards or Pulitzer Prizes, no ads, no publicity, not even word of mouth to guide me.”

She is not the first writer to set off on an armchair expedition. A. J. Jacobs, a self-described “human guinea pig,” spent a year reading the encyclopedia for “The Know-It-All: One Man’s Humble Quest to Become the Smartest Person in the World” (2004). Ammon Shea read all of the Oxford English Dictionary for his book “Reading the OED: One Man, One Year, 21,730 Pages” (2008). In “The Whole Five Feet” (2010), Christopher Beha made his way through the Harvard Classics during a year in which he suffered serious illness and had a death in the family. In “Howard’s End Is on the Landing” (2010), Susan Hill limited herself to reading only the books that she already owned. Such “extreme reading” requires special personal traits: grit, stamina, a penchant for self-improvement, and a dash of perversity.

Rose fits the bill. A retired English professor, she is the author of popular biographies of Virginia Woolf and Josephine Baker, as well as “The Year of Reading Proust” (1997), a memoir of her family life and the manners and mores of the Key West literary scene. Her best book is “Parallel__ Lives”__ (1983), a group biography of five Victorian marriages. (It is filled with marvellous details and set pieces, like the one in which John Ruskin, reared on hairless sculptures of female nudes, defers consummating his marriage to Effie Gray for so long that she sues for divorce.) Rose is consistently generous, knowledgeable, and chatty, with a knack for connecting specific incidents to large social trends. Unlike many biblio-memoirists, she loves network television and is refreshingly un-nostalgic about print; in “The Shelf” she says that she prefers her e-reader to certain moldy paperbacks.

She is clear-eyed about what awaits her on LEQ-LES. “I had no reason to believe that the books would be worth the time I would spend on them,” she writes. “They could be dull, even lethally so.” She stops short of claiming that the whole of a mediocrity is worth more than the sum of its parts; it is the uniqueness of her whole that excites. “I was certain, however, that no one in the history of the world had read exactly this series of novels.” Rose’s paean to arbitrariness is telling. She brings an element of chaos to a reading culture that is otherwise corralled by algorithms. She could read this shelf or that shelf or that other shelf over there. For her, arbitrariness doesn’t mean that her experience is interchangeable. It is, on the contrary, irreplaceable.

The way most of us choose our reading today is simple. Someone posts a link, and we click on it. We set out to buy one book, and Amazon suggests that we might like another. Friends and retailers know our preferences, and urge recommendations on us. The bookstore and the library are curated, too—the people who work there may even know you and track your habits—but they are organized in an impersonal way. Shelves and open stacks offer not only immediate access to books but strange juxtapositions. Arbitrary classification breeds surprises—Nikolai Gogol next to William Golding, Clarice Lispector next to Penelope Lively. The alphabet has no rationale, agenda, or preference.

Rose first gets the idea for “The Shelf” while browsing the stacks of the New York Society Library, on the Upper East Side. Founded in 1754, it is the oldest library in the city, a place where a grandfather clock keeps time and the décor runs to “marble, murals, and mahogany.” (Its patrons have included George Washington, Herman Melville, and Willa Cather, and though the reference room is open to the public, to borrow books you must pay a yearly membership fee of two hundred and twenty-five dollars.) Rose has gone to the library to get the book “Hurricane,”__ by Charles Nordhoff and James Norman Hall (of “Mutiny on the Bounty” fame), recommended by friends who were on their own mission to become Nordhoff and Hall completists. But when she finds the book she realizes that she does not want to read it after all. Looking around idly, she sees dozens of Nordhoff and Hall titles, and she has never heard of any of them. “What were the other books like?” she wonders. “Who were all these scribblers whose work filled the shelves? Did they find their lives as writers rewarding? Who reads their work now? Are we missing out?” It is a decidedly contemporary feeling, this FOMO, this fear of missing out. She will conquer it.

Her shelf, she decides, must have a combination of new and older works by several authors, both men and women, and one book has to be a classic that she has always wanted to read. The shelf cannot contain any work by a person she knows. She surveys some two hundred shelves, and eventually settles on LEQ-LES. It holds twenty-three books by eleven authors, including “A Hero of Our Time,”__ by Mikhail Lermontov; Gaston Leroux’s “The Phantom of the Opera”; novels by Rhoda Lerman, Margaret Leroy, and Lisa Lerner; and Alain-René Lesage’s “Gil Blas.” (There are only three female authors in her sample, a fact that she analyzes at length, though she does not comment on its racial monotony.) She has never before read any of these titles, and she will read them in whatever order fancy suggests. “The Shelf” reviews facts about each author’s life and summarizes the plots of the novels, but, always, the real focus is on Rose herself: what she likes and dislikes, how she feels while reading, whether it is easy or difficult to escape into the story. She’s on the lookout for “spontaneity, inclusiveness, and uniqueness”—three things that she prizes in fiction, and three of the elements driving her project, too.