BOOKS. THEY HAVE AN ALMOST alarming corporeality. Stephen Greenblatt, esteemed Harvard professor and founder of New Historicism, tells us that between the eras of papyrus and paper, books were often made of the pumice-smoothed skins of sheep, goats, deer, or, most luxuriously, of an aborted calf. The act of writing required rulers, awls, fine pens, and weights to keep the surfaces flat. Ink was a mix of soot, water, and tree gum; it was revised with knives, razors, brushes, rags, and page-restoring mixtures of milk, cheese, and lime. Squirming black creatures called bookworms liked to eat these pages, along with wool blankets and cream cheese. In the silence of monastery libraries, even the books' contents were indicated by bodily gestures. Monks copying pagan books requested them by scratching their ears like dogs with fleas, or, if the book were particularly offensive, shoving two fingers in their mouths, as if gagging. In Greenblatt's The Swerve: How the World Became Modern, these objects, offensive or sacred, are the primary players.

Those who tended to, or searched for, or even wrote the books — monks, Renaissance book hunters, and ancient Greek and Roman poets and philosophers — are decidedly secondary in The Swerve. Though "nothing lasts forever," as Greenblatt mournfully says of papyrus, which crumbles in a few centuries, poor humans don't last nearly as long as that substance, or even as long as a solidly bound and decently stored modern paperback. This rings all too true for Greenblatt, who lived with a mother obsessed with her imminent death. (She died quite old, after having spent decades instilling grim terror in her son, as he admits in a frank preface.) In The Swerve, however, death is nothing, and people aren't much either. 

The book's central character is a six-volume, two-millennia-old poem, Lucretius's On the Nature of Things, that imagines a world made of crashing, combining atoms, denies life after death, prescribes the pursuit of pleasure as the rational goal of individuals and societies, and suggests that all things arise from a swerve - a slight and random deviation from course. The swerve of Greenblatt's title does not refer to the work of Gutenberg or Newton or any of those most often credited with ushering in the world as we know it, but to the resurrection of Lucretius's poem. Greenblatt describes the hunt for the text with great narrative panache. In his least poetic and most bullet-pointed chapter, he traces, lightly and somewhat vaguely (perhaps out of deference), the poem's role in the Renaissance, the Enlightenment, and even the establishment of the American Republic. Though somewhat hyperbolic, as such claims tend to be, the idea that a recovered text transformed the world offers some comfort to anyone worried about the long-touted death of the book. 

It can be said that two men are responsible for the continued existence of On the Nature of Things: Lucretius, its author, and Poggio Bracciolini, its hunter. Of Lucretius almost nothing is known; an unkind, five-line biography by St. Jerome, disregarded by modern historians, has Lucretius going mad after drinking a love potion and then committing suicide. Poggio's life has a far clearer outline, recorded in letters and essays. He was born at the end of the 14th century in Tuscany and rose from a modest background to serve eight popes as o...