VATICAN CITY (CNS)—Pope Francis’ first encyclical, “Lumen Fidei” (“The Light of Faith”), released July 5, is the latest installment in a centuries’ old papal tradition. 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)

One of 38 encyclicals issued by Pope Pius IX, whose almost 32-year pontificate was the longest in history after St. Peter’s, this document is best known for an annex called the “Syllabus of Errors,” a list of “condemned propositions” associated with contemporary religious, philosophical and political movements, including communism, socialism and liberalism. Although the document drew heavily on the teachings of earlier popes, historians have placed it in the context of the European revolutions of 1848. 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 predicament 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 labor.” The encyclical, which rejected both communism and extreme laissez-faire capitalism, affirmed the right of workers to organize in unions and was crucial to the emergence of a Catholic labor movement. With its strong basis in the theology of St. Thomas Aquinas, it also provided the foundation for the church’s modern social teaching.

“Pascendi Dominici Gregis” (1907)

St. Pius X’s encyclical was a condemnation of modernism, a European Catholic movement influenced by currents in 19th-century Protestantism, which held that even solemnly defined church teachings could evolve over time, and sympathized with secularist conceptions of the separation of church and state. St. Pius later required all priests, religious superiors and seminary teachers to take an oath against the modernist heresy—a requirement that 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 on Palm Sunday. 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. A significant contributor to the document was Cardinal Eugenio Pacelli, then Vatican secretary of state and later Pope Pius XII, whose record of wartime opposition to the Holocaust remains a subject of controversy.

“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 that promote their well-being, from labor unions to 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. Pope Paul never issued another encyclical in the remaining 10 years of his pontificate. On the document’s 40th anniversary, Pope Benedict XVI called it “so controversial, yet so crucial for humanity’s future … a sign of contradiction … (and) of courage in reasserting the continuity of the church’s doctrine and tradition.”

“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 labor and insisted that the end of the Cold War did not leave “capitalism as the only model of economic organization.” The document was innovative in the annals of papal social teaching by virtue of its qualified praise for the free market as the “most efficient instrument for utilizing resources and effectively responding to needs.”