“Pacem in Terris inserted the Catholic Church firmly into the late-20th century debate on human rights, which proved to be such an important tool in the hands of those who eventually brought down the Berlin wall and thus made an enormous contribution to peace,” Catholic writer George Weigel told the Catholic World Report.Humanae Vitae, Paul VI 1968: Humanae Vitae threw down the gauntlet on the issue of contraception, making it one of the most controversial and disliked encyclicals of all time.
At one time, artificial contraception was universally viewed as sinful among Christians.
But, at the 1930 Lambeth conference, the Anglican church reversed its position, prompting Pius XI to issue Casti Connubii, making it clear that the Catholic Church was not about to follow suit, even as many other Protestant denominations did.
Without taking an anti-scientific stance, the pope affirmed an uncompromising doctrine of inerrancy against those who claimed the Bible is only without error in narrow matters of faith and morals.
Catholic biblical theology has never been the same since.
But it also called out greedy industrialists for abusing workers and affirmed the right of the state to intervene on their behalf. Rerum Novarum has inspired other encyclicals too, most notably Quadragesimo Anno, itself an indispensable pillar of Catholic social teaching.
At a time of great social upheaval, the encyclical thus sketched out a uniquely Catholic response to the challenges of worker rights, urbanization, industrialization—avoiding the extremes of both socialism and laissez faire capitalism. Distributist themes are even reflected in one of the most all-time popular Christian works of fiction: The Lord of the Rings.
This inspired a movement known as distributism, so named because its adherents believe property ownership should be widely distributed, instead of concentrated in the hands of wealthy robber barons or socialist bureaucrats. Providentissimus Deus, Leo XIII 1893: There had been other encyclicals on the Bible before, but none as momentous as this, and probably none since.
Providentissimus Deus drew a battle line against modernism: Leo XIII declared that it is inconsistent to say that the Bible has errors and was still divinely inspired.
In this warning are the seeds of the later emphasis on Bible reading among lay Catholics.
Leo XIII himself expressed a “desire that this grand source of Catholic revelation should be made safely and abundantly accessible to the flock of Jesus Christ.” Pascendi Dominici Gregis, Pius X 1907: In this encyclical, the Catholic Church declared war on modernism.
In particular, it set the stage for his confrontation with communism, rooted in John Paul II’s emphasis on the dignity of the human person and his personal encounter with Christ.