This is a book about the philosophical epic poem De Rerum Natura ("On the Nature of Things") by Lucretius, written circa first century BC. It tells of its loss in Medieval times and later rediscovery during the Renaissance.
The title, The Swerve, is used (in translation) by Lucretius to describe the unpredictable movements by which particles collide and take on new forms. The rediscovery of Lucretius, it is suggested, was a kind of "swerve" which helped to create the new cultural forms of the Renaissance. The subtitle of "how the World Became Modern" is a bit of an overstatement, but this book does illuminate an interesting moment of cultural significance and provide a summary review of the history of books. It's interesting to note that the British publication of this book had a different subtitle, "How the Renaissance Began" which is just as much an overstatement and raises the question, "Why do the Brits get a different title?"
I have my own interpretation of a second meaning for the title of this book. The title The Swerve brings to my mind the shift in cultural prestige that took place with the coming of the Enlightenment era when the most respected intellectuals became those who questioned perceived wisdom instead of those who meditated on revealed wisdom. The leading thinkers of the first century BC (when Lucretius lived) valued asking questions in the spirit of Greek philosophy. After the rise of Christianity and fall of the western part of the Roman Empire the leading thinkers changed to those who elaborated on the meanings of revealed truth contained in scripture. The coming of the Renaissance and Enlightenment constituted a "swerve" back to the intellectual direction of Lucretius' time.
The story told by this book begins with Poggio Bracciolini visiting at a monastery in central Germany – almost certainly the Benedictine abbey of Fulda - searching for old manuscripts. What he found was a ninth-century manuscript copy containing the entire 7,400-line text of De Rerum Natura ("On the Nature of Things") by Lucretius. This extraordinary philosophical epic poem, composed in Rome around the middle of the first century BC, was in 1417 known only by references by other authors. Distant hints of its initial impact could be heard in a letter of Cicero's of 54 BC, which spoke of its "brilliant genius"; in Ovid's commendation of "the sublime Lucretius"; and in Virgil's lines from the Georgics, "Blessed is he who has succeeded in finding out the causes of things, and has trampled underfoot all fears."
At the time of its discovery and for many years later it was the only known copy of the epic poem. Over the years a few other copies (or fragments) have been discovered, so it wasn't the sole surviving copy as it turned out. The copy found in Germany by Poggio and the copy made for him by a German scribe no longer survived today. But the beautiful transcript made back in Italy by his friend Niccolò de' Niccoli survives today. It is probably no accident that so few copies of "On the Nature of Things" survived the Medieval era. The epic poem by Lucretius espoused ways of thinking that early Medieval church leaders found threatening to their cause.
The history covered by this book includes; (1) The contrast between Roman intellectual thinking and the relatively coarse Latin contained in Christian codexes, (2) The history and fate of ancient Greek and Roman public libraries including the famous library at Alexandria, Egypt, (3) The preoccupation of some of the famous early Christian leaders with suffering which contrasted with Epicurean philosophy, (4) The career of Poggio Bracciolini within the environment of endemic corruption of the Roman Catholic Church (it was the era of three Popes), (5) A summary description of the contents of De Rerum Natura ("On the Nature of Things") by Lucretius, and (6) the history of how later writers and thinkers of the Renaissance and Enlightenment responded to the long poem by Lucretius.
The quotations from "On the Nature of Things" contained in this book are surprising close to an accurate description of theories of atoms and natural selection. Of course Lucretius is speaking as a philosopher and not from observations of scientific discovery. Nevertheless, they sound surprisingly modern.
One little bit of trivia that I learned from this book was contained in the discussion of Thomas More's book, Utopia. More's description of Utopia included capital punishment for those who didn't believe in God and the afterlife. In other words, Moore couldn't imagine people living in peace without the fear of punishment after death for bad behavior. The fear of execution in this life was replaced by fear of hell in the afterlife. The word "utopia" will never be the same for me.