Saint Augustine of Hippo, revered now as one of the most formative influences on Western Christianity, was once just a confused young playboy.

A childhood spent pilfering pears from his neighbor’s tree, shacking up with unmarried women, and fathering a child out of wedlock led him to an identity crisis at the ripe age of 31. Augustine realized the error of his ways when he heard the phantom voice of a small child calling to him. Over and over again, the voice chanted, “Pick it up. Read it. Pick it up. Read it.”

Augustine interpreted the command to be about the Bible and flipped to the first passage he could find. As his eyes absorbed the divine content, he was transformed.

“Instantly, as the sentence ended, there was infused in my heart something like the light of full certainty, and all the gloom of doubt vanished away,” Augustine wrote in his now-famous tome Confessions.

Not only did he become a Christian, molding the Western canon of philosophy and religion for centuries to come, but as Rebecca L. Davis asserts in Public Confessions, Augustine originated a tradition of conversions on the public stage. By melding what had historically been an external process of movement from one group to another with the interior journey of discovering one’s self anew, Augustine set the stage for Clare Boothe Luce, Sammy Davis Jr., and Muhammad Ali, celebrity converts who Davis follows in her project to understand the modern-day formation of identity.

Public Confessions may be a book about conversions. But Davis doesn’t set out to fully excavate her subjects’ internal motivations. Instead, the history professor is concerned with how these public conversions tracked for an often skeptical audience and what they have to reveal about the ability of individuals to shape politics. In Augustine’s case, after converting, his sermons were raptly attended by dedicated adherents, and he went on to earn Christianity’s highest exaltation: sainthood. In the process, he became one of the most important and powerful public figures of his time. 

Davis, however, is much more interested in Augustine’s 20th-century counterparts, some of whom enjoyed a less favorable reception. Upon converting to Judaism, Davis Jr. lost his standing among fellow Black entertainers and throngs of Black fans. And after joining the Nation of Islam, Ali dodged the Vietnam War draft on religious grounds, prompting him to be stripped of his boxing titles and banned from competing anywhere in the United States. It’s clear, Davis argues, that converts’ stories had immense ramifications for society. They raised questions about “the role of religion in shaping public life.” They upended conversations about the Cold War, shaped the fight against communism, and changed the civil rights movement. They helped mold a political climate in which spirituality skewed political.