VATICAN CITY – An encyclical is considered the most authoritative form of papal writing, and though many examples are now remembered only by scholars, the messages of others have continued to resonate within the Church and beyond.
Here are seven whose impact has proven especially memorable:
Quanta Cura (1864): Pope Pius IX's document is best known for an annex called the Syllabus of Errors, a list of "condemned propositions" associated with movements of the time, including communism, socialism and liberalism.
For many Catholics and non-Catholics, it established the Church's image as resolutely opposed to modernity, an image widely accepted until the Second Vatican Council a century later.
Rerum Novarum (1891): Responding to the situation of the working class in the wake of the industrial revolution, Pope Leo XIII wrote this document laying out the "rights and duties of capital and labour." The encyclical, which rejected both communism and extreme capitalism, affirmed the right of workers to organize in unions and provided the foundation for the Church's modern social teaching.
Pascendi Dominici Gregis (1907): St. Pius X's encyclical condemned modernism, a European Catholic movement influenced by currents in 19th-century Protestantism, which held that even solemnly defined Church teachings could evolve over time. St. Pius later required all priests, religious superiors and seminary teachers to take an oath against the modernist heresy - a requirement Pope Paul VI abolished in 1967.
Mit Brennender Sorge (1937): Pope Pius XI's encyclical, whose German title means "with burning concern," was smuggled into Nazi Germany and read from the pulpits of Catholic churches. Although it does not explicitly mention Adolf Hitler or the Nazi party, it criticizes the regime's "myth of race and blood" and cult of the state and defends the value of the Old Testament and the rights of ethnically Jewish Catholics, though not of Jews in general.
Pacem in Terris (1963): Blessed John XXIII's last encyclical was the first such document addressed not just to fellow Catholics but to "all men of good will." Writing at the height of the Cold War, Blessed John called for international and interreligious cooperation for the promotion of world peace.
Emphasizing the importance of human rights and dignity, the encyclical also recognized the rights of all people to food, water, safety, housing, health care, involvement in public life and affiliation in organizations such as labour unions and civic groups.
Humanae Vitae (1968): Pope Paul VI's decision to affirm the Church's traditional prohibition against artificial contraception was met by dissent from a number of prominent theologians and, as demographic evidence suggests, widespread disobedience by ordinary Catholics.
Centesimus Annus (1991): Issued on the hundredth anniversary of Rerum Novarum, Blessed John Paul II's encyclical reaffirmed Pope Leo's expressions of solidarity with the poor and organized labour and insisted that the end of the Cold War did not leave "capitalism as the only model of economic organization."
The document gave qualified praise for the free market as the "most efficient instrument for utilizing resources and effectively responding to needs."