It was once assumed that religious freedom was a work of the Enlightenment. In the sixteenth century, so the story goes, when the Reformation made its way across Europe, confessional differences led to the suppression and persecution of Christians by Christians. As the decades passed, religious differences hardened and Protestant and Catholic armies faced one another on the field of battle. A half-century of bloody conflict, the so-called wars of religion, was set in motion. But by the middle of the seventeenth century, men with greater wisdom and less religious fervor entered the scene and the fanaticism of religious believers gave way to the cool reason of philosophers. Armed with notions about the superiority of reason to faith, skeptical of received truth, and distrustful of religious claims and institutions, these enlightened thinkers forged a new set of ideas about toleration and religious freedom. Through their labors the modern idea of liberty of conscience was born.

This tale has been modified in recent decades. John Locke, whose Letter Concerning Toleration, published in 1689, was viewed as a charter document of religious freedom, has been deposed from his place of honor. He was a latecomer to the project of religious freedom, and his key ideas are found in earlier writers. In her book Liberty of Conscience, Martha Nussbaum argued that the first and most articulate exponent of liberty of conscience was Roger Williams, who lived two generations before Locke. But she ignores the religious and intellectual background of his thinking. A hundred years ago an Austrian scholar, George Jellinek, traced the roots back to the Reformation era, particularly to the Puritans. “The idea of legally establishing inalienable, inherent and sacred rights of the individual is not of political but religious origin.”

All these accounts move within too narrow a historical horizon. The roots of religious freedom in the West are to be found many centuries earlier, in the writings of Christian apologists who wrote in defense of the right to practice their faith in the cities of the Roman Empire. This essay traces the early history of religious freedom in the West and shows how it provided the tools for Christian thinkers in the early modern period to formulate a full doctrine of religious freedom and liberty of conscience.