Robert Louis Wilken opens Liberty in the Things of God with this proposition, which American readers likely will find unobjectionable, if not self-evident: “Religious freedom rests on a simple truth: religious faith is an inward disposition of the mind and heart and for that reason cannot be coerced by external force.” And yet, throughout history, this seemingly unobjectionable, self-evident proposition has been more honored in the breach than in the observance.

Consider, for example, the history of Christianity, which was born in the fires of persecution. When Christians became Roman emperors, the formerly persecuted turned imperial power into a sword against pagans, Jews, and heretics. In the wake of the Reformation, imperial uniformity devolved into Wars of Religion and resulted in a patchwork of Catholic and Protestant kingdoms and principalities governed by the Latin formula cuius regio, eius religio — “whose realm, his religion.” Essentially, each kingdom or principality had its established church, and woe betide the people whose religion didn’t match their prince’s!

Exhausted by these religious conflicts, Enlightenment thinkers such as John Locke began to propose a better way. At first, this was tolerance of other religions. Tolerance is the willingness of a majority to countenance minorities; however, that willingness can wane. So tolerance gave way to freedom, which requires the state to protect religious freedom, especially that of the minorities, as a matter of believers’ natural right. The First Amendment of the U.S. Constitution is a shining example of this kind of freedom: “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof.”

“It was early Christian teachers who first set forth ideas of the freedom of the human person in matters of religion.” –Robert Louis Wilken

Unfortunately, this brief survey leaves the impression that Christendom was a problem the Enlightenment had to solve. This is a mistake because it overlooks the Christian history of the proposition I stated at the outset of this review. In reality, the Enlightenment drew on ideas that had been circulating among Christians for nearly 1,500 years. The Christian origins of religious freedom is the theme of Liberty in the Things of God.

Wilken traces the intellectual history of religious freedom to Tertullian (ca. 155–240), a  Christian apologist who lived in Roman North Africa and was evidently the first person in Western civilization to use the phrase “freedom of religion” (libertas religionis). “It is only just and a privilege inherent in human nature that every person should be able to worship according to his own convictions,” Tertullian wrote; “the religious practice of one person neither harms nor helps another. It is not part of religion to coerce religious practice, for it is by choice not coercion that we should be led to religion.”

For Tertullian and other Christian apologists of this era, religion was a matter of both individual conscience and corporate practice. Because it was a matter of individual conscience, religion had to be chosen not coerced, a choice made “only by words, not by blows,” as Lactantius (ca. 250–325), a later Christian apologist, put it. Because it was a matter of community practice, religious freedom pertained to groups, not just individuals. Regarding this, Wilken makes a salient point: “The phrase ‘freedom of religion’ enters the vocabulary of the West with reference to the privileges of a community, not to the beliefs of individuals,” or at least, not merely to those beliefs.

Because religious freedom was for the early Christians a matter of both conscience and community, it necessitated limitations on the powers of government. Jesus Christ had said, “Give back to Caesar what is Caesar’s and to God what is God’s” (Mark 12:17), and Christians returned to this passage and others like it to limn the boundaries between the institutions of church and state.

While early Christian apologists such as Tertullian lived at a time when Christians were a persecuted and powerless, though rising, minority, most of Western Christian history has taken place with Christians as the powerful majority. The bulk of Wilkens’ book describes the long millennium between Constantine’s conversion (early fourth century) and the dawn of the Enlightenment (late 17th century), the bookends of Christendom. During this period, Christians donned the habits of pagan Romans and attempted to use government to pursue religious ends.

What’s fascinating in this topsy-turvy scenario is that Christian groups on the wrong side of state power continued to use the arguments pioneered by Tertullian and the early Christian apologists. They appealed to conscience to limit government’s power over a community’s religious practice. At the Diet of Worms (1521), Martin Luther famously explained his refusal to recant with these words: “My conscience is captive to the Word of God. I cannot and I will not recant anything, for to go against conscience is neither right nor safe.” He was speaking to Catholic authorities. Four years later in Nuremberg, when Lutheran magistrates tried to stop Franciscan nuns from practicing their Catholicism, Abbess Caritas von Pirckheimer wrote of the magistrates, “They knew very well that we had always obeyed them before in all temporal things. But in what concerned our soul, we could follow nothing but our own conscience.”

Conscience. Community. Limits. These were the touchstones of religious freedom that stemmed from Tertullian and other Christian apologists and continued to operate as such throughout Christendom whenever the powers that be overstepped their boundaries. When, therefore, John Locke and other early Enlightenment figures began to argue for first toleration and then freedom of religion, they were sowing seeds in ground long ago plowed by Tertullian and Lactantius.

I conclude my review with Wilkens’ closing words:

It was early Christian teachers who first set forth ideas of the freedom of the human person in matters of religion; it was Christian thinkers who contended that conscience must be obedient only to God; and it was the dualism of political and spiritual authority in Christian history that led to the idea that civil government and religious belief must be kept separate. The process by which the meditations of the past become the certainties of the present is long and circuitous. But by the eighteenth century ideas on religious liberty advanced by earlier thinkers had become the property of all…

These are the Christian origins of religious freedom, a historical story well worth Robert Louis Wilken’s telling of it.

Book Reviewed
Robert Louis Wilken, Liberty in the Things of God: The Christian Origins of Religious Freedom (New Haven, CT: Yale University Press, 2019).