The Swerve: How the World Became Modern by Stephen Greenblatt Norton, 356 pp., $26.95

Stephen Greenblatt’s The Swerve celebrates an ancient Latin poem. So, as he shows, did the scholars and scribes who brought it back into circulation in Renaissance Europe. The frontispiece of one manuscript suggests something of what they found in it (see illustration on this page). On it stands a classical arch, adorned with colored marble and sculpted capitals, standing before a landscape with river, cliffs, and a spindly, towering tree—the kind of imaginary country you usually see in fifteenth-century paintings of saints receiving the stigmata. On the pediment and in front of the base, naked putti run about. Two of them hold a giant compass: a hint that the text that follows may hold secrets about how the universe was made. Two more hold up a tablet, with a Latin verse written on it in classical capitals:

ENEADVM GENITRIX HOMINVM DIVVMQVE VOLVPTAS (Mother of the descendants of Aeneas, delight of men and Gods)

Four more cherubic stagehands, two at the top and two at the bottom, use cords to stretch an enormous piece of what looks like skin across the entire opening of the arch. This bears thirteen more lines of Latin verse: a marvelous description, charged with passion and energy, of spring, as the earth becomes fertile once more, and breezes and flowers herald the erotic dance in which all creatures will soon join.

Standing on the top of the arch, two more putti hold up another tablet that identifies the book for which this humanist fantasia is merely the extravagant title page: “The first book of Titus Lucretius, the celebrated Epicurean poet.” Go (virtually) through the arch and you’ll find On the Nature of Things, the remarkable Latin poem in six books that is the only surviving work of the Roman poet Titus Lucretius Carus, written in a handsome script. This manuscript was copied by an Augustinian friar, Girolamo di Matteo de Tauris, in 1483, for Pope Sixtus IV. It now belongs to the great library that he did so much to create, where it holds the unromantic shelfmark Vat. lat. 1569.

The story seems simple enough. In the fifteenth century, the new culture of Renaissance humanism, with its sense of new possibilities inspired by the past, filled rulers throughout Italy with enthusiasm. Clever manipulators like Cosimo de’ Medici and ruthless soldiers of fortune like Federigo da Montefeltro appointed fluent Latinists to write propaganda for them, studied the ancients themselves, and collected as many classical texts as they could. Contemporary popes, scions of aristocratic Italian families and Renaissance princes in their own right, followed suit. Pope Nicholas V created, and Pope Sixtus IV expanded and institutionalized, the Vatican Library: a humanistic collection,…