Poggio Bracciolini found the 7,400-line poem by the Roman writer Lucretius in a monastic library in Germany. “On the Nature of Things” soon became a classic commentary on science, philosophy and religion, even though the Catholic Church denounced it as heresy.

“The Swerve” reads like a page-turning detective story, as Stephen Greenblatt, a humanities professor at Harvard University, delves into the life of an obscure historical figure and his chance discovery of this important cultural commentary written before Christ was born.

Of the thousands of books written in ancient Greece and Rome, only a small number have survived. Most perished in fires or floods, or simply crumbled to dust. Some, including “On the Nature of Things,” were hand-copied by monks in Catholic monasteries before the advent of modern printing.

Lucretius wrote that atoms were the building blocks of all existence. He rejected belief in God, taught that the human soul dies with the body, said there is no afterlife, found that organized religions were superstitious delusions, and wrote that the highest human goal is the pursuit of happiness and reduction of pain, an idea he borrowed from the Greek philosopher Epicurus.

Lucretius believed that the greatest obstacle to happiness is inordinate desire, which is close to what the Buddha had taught centuries before.

Much of what Lucretius said about the universe having come from a clash of atoms in an infinite void seemed absurd, Greenblatt says, but his ideas “turned out to be the basis for the contemporary rational understanding of the entire world.”

As the book’s title suggests, “On the Nature of Things” pushed the world to shift, or swerve, in a new direction.

Greenblatt convincingly captures the centuries-long clash between science and philosophy, on the one hand, and rigid Church doctrine on the other.

He reminds us of the abuses and atrocities carried out by the Catholic Church, such as the practice of torturing alleged heretics and burning them at the stake. Galileo was sentenced to life in prison because he taught that the Earth revolved around the Sun.

Poggio was well-known for his consuming interest in ancient books and his excellent handwriting. He had served as papal secretary to a Pope who eventually was stripped of his title and expelled from the Church at a time when three men each claimed to be the official Pope.

On the final pages of this absorbing celebration of ancient literature and wisdom, Greenblatt reveals that Thomas Jefferson owned at least five Latin editions of “On the Nature of Things.” Jefferson believed that the role of government was not only to secure the lives and liberties of citizens, but also to facilitate “the pursuit of happiness.”

“The atoms of Lucretius,” Greenblatt concludes, “had left their traces on the Declaration of Independence.”