It can therefore be surprising to remember how recent religious liberty’s popularity is. Few institutions reflect this better than the Catholic Church, which as recently as the early 1960s openly condemned religious freedom as heresy. Throughout the nineteenth century and well into the twentieth, Catholic bishops and theologians claimed that the state was God’s “secular arm.” The governments of Catholic-majority countries therefore had the duty to privilege Catholic preaching, education, and rituals, even if they blatantly discriminated against minorities (where Catholic were minority, they could tolerate religious freedom as a temporary arrangement). As Pope Gregory XVI put it in his 1832 encyclical Mirari vos, state law had to restrict preaching by non-Catholics, for “is there any sane man who would say poison ought to be distributed, sold publicly, stored, and even drunk because some antidote is available?” It was only in 1965, during the Second Vatican Council, that the Church formally abandoned this conviction. In its Declaration on Religious Freedom, it formally proclaimed religious liberty as a universal right “greatly in accord with truth and justice.” This was one of the greatest intellectual transformations of modern religious thought.
Why did this change come about? Scholars have provided illuminating explanations over the last few years. Some have attributed it to the mid-century influence of the American constitutional tradition of state neutrality in religious affairs. Others claimed it was part of the Church’s confrontation with totalitarianism, especially Communism, which led Catholics to view the state as a menacing threat rather than ally and protector. My article in the July 2018 issue of the Journal of the History of Ideas uncovers another crucial context that pushed Catholics in this new direction. Religious liberty, it shows, was also fueled by a dramatic change in Catholic thinking about Protestants, namely a shift from centuries of hostility to cooperation and even a warm embrace. Well into the modern era, many Catholic writers continued to condemn Luther and is heirs, blaming them for the erosion of tradition, nihilism, and anarchy. But during the mid-twentieth century, Catholics swiftly abandoned this animosity, and came to see Protestants as brothers in a mutual fight against “anti-Christian” forces, such as Communism, Islam, and liberalism. French Theologian Yves Congar argued in 1937 that the Church transcends its “visible borders” and includes all those who have been baptized, while German historian Joseph Lortz published in 1938 sympathetic historical tomes that depicted Martin Luther and the Reformation as well-meaning Christians. This process of forging inter-Christian peace—which became known as ecumenism—reached its pinnacle in the postwar era. In 1964, it received formal doctrinal approval when Vatican II promulgated a Decree on Ecumenism (1964), which declared Protestants as “brethren.”
One venue in which this new view of Protestants played out was in the translation of the Bible. I write about this extensively in Chapter 22 of The Bible Cause: A History of the American Bible Society.