On March 6, 1854, a gang of ruffians associated with the anti-Catholic Know-Nothing Party smashed a block of marble that Pope Pius IX had sent to America as a contribution to the Washington Monument; the Know-Nothings dumped the broken pieces of stone into the Potomac River. Seventy-four years later, New York Gov. Al Smith discovered that being Catholic was still a distinct liability in presidential politics; the 1928 campaign was rife with anti-Catholic propaganda, which contributed to Smith’s overwhelming defeat by Herbert Hoover. The idea that there was an inherent tension in being both a faithful Catholic and being a patriotic American eventually abated.

If Catholics had to travel a rocky road on the way to full political acceptance in the United States, the modern papacy also had to traverse a difficult path in claiming a place at the table where the world’s future is debated. The low point of the papacy’s engagement with international public life was undoubtedly the early 20th century. In 1914-15, the Italian government was so intent on keeping Pope Benedict XV in diplomatic limbo that Italy demanded secret British guarantees that the Holy See would be prohibited from participating in any post-war peace conference as a condition of Italy’s jumping sides in World War I.

In 1919, when the Versailles conference was redrawing the map of Europe, the Holy See had full diplomatic relations with only 26 countries, most of them in Latin America. Yet things also began to change on this front, thanks to the generosity of Benedict XV (who bankrupted the Vatican providing aid to prisoners and refugees during World War I), the anti-totalitarian witness of Popes Pius XI and Pius XII, and the universal affection showered on Pope John XXIII, whose 1963 encyclical, Pacem in Terris (Peace on Earth), seemed to speak to and for all humanity.

Thus when Pope Paul VI came to New York in October 1965 for the first papal visit to the United States and the United Nations, he was received not as an intrusive, anti-democratic foreign monarch, nor as someone strikingly out of place in arenas where serious people discuss big questions. Rather, Paul VI came to the U.N. as the holder of an office that had developed the capacity to speak to the world about its deepest moral and spiritual concerns in a unique way.

The emergence of the papacy as a universal moral reference point, which gives popes a unique form of power in international affairs, was a slow process. British historian Owen Chadwick traces its modern beginnings to Pope Gregory XVI’s 1839 condemnation of the slave trade. The pope had no capacity to enforce his condemnation, but he denounced it nonetheless, in what was perhaps the first effort at papal moral persuasion on a global scale. Gregory’s successor, Pius IX, was esteemed by the world’s Catholics, but had virtually no influence on international affairs. It was left to his successor, Pope Leo XIII, to devise a new method of papal interaction with the world.

Leo took a cue from Gregory XVI and began to reposition the papacy as a new kind of actor in world politics: a moral teacher and witness. His great social encyclical of 1891, Rerum Novarum, discussed the “new things” of the industrialized world with a lucidity that would inspire social reformers for generations. Pius XI picked up where Leo XIII left off, and in the 1931 encyclical Quadragesimo Anno, brilliantly analyzed the totalitarian temptation to which much of Europe was succumbing, even as he extended the social doctrine of the Church into a comprehensive vision of a just society. John XXIII continued this tradition of papal social teaching and got the world’s attention and respect with his aforementioned encyclical, Pacem in Terris.

Thus when Paul VI stepped to the green marble rostrum of the U.N. General Assembly in 1965, he was standing on the shoulders of papal giants who had redefined the Vatican’s power in the modern world. This was no longer the power to bring penitent princes to their knees (as Gregory VII had done to the Holy Roman Emperor Henry IV); this was a different and great power — the power of moral persuasion, which changes history by changing minds.

Yet, Paul VI’s injunction “No more war, war never again!” has, clearly, not been heeded. It would take another pope, John Paul II, to demonstrate just how effective the Vatican’s new change-through-moral-argument strategy could be.

When John Paul II came to the U.N. in October 1979, it was less than four months after his triumphant return to his native Poland. There, he had ignited a revolution of conscience that, in the summer of 1980, gave birth to the Solidarity movement at the Gdansk shipyards. By giving back to his fellow Poles their authentic history and culture — which the Nazis had tried to destroy from 1939 until 1945, and the Communists had been trying to usurp since 1945 — John Paul gave his people the tools of resistance that totalitarian truncheons could not break.

At the U.N., John Paul broadened and “globalized” his message of human rights as the foundation of a just society, laying special emphasis on the fundamental right of religious freedom. As Sen. Daniel Patrick Moynihan (a former U.S. ambassador to the U.N.) put it afterwards, the message had been received by at least some of those for whom it was intended. Moynihan said, “I can attest from having watched that the eastern European and Soviet delegates knew exactly what he was talking about, and for once in that chamber, [they] looked fearful rather than bored.”

John Paul II spoke a genuinely universal moral language — and in doing so, showed the world that it was indeed possible to have a global moral conversation, despite the complexity of human differences.

By the time he returned to the U.N. in 1995, John Paul’s revolution of conscience had triumphed in Central and Eastern Europe, leading to the end of European communism and the fall of the Soviet Union. But the pope, who was always thinking ahead, discerned new dangers on the horizon. The world’s remaining communists, as well as East Asian authoritarians, radical Muslims, and postmodern Westerners, were all arguing in their various ways that “human rights” was an idea concocted by the West to be imposed on others.

Not so, insisted John Paul II. There is, he argued, a universal moral law written on the human heart; we can know this law if we think carefully about the moral life. This universal moral law discloses certain human rights that every just government must acknowledge and protect, no matter what the cultural circumstances. Moreover, the pope continued, this universal moral law can be a “grammar” that disciplines the world’s debate over the future.

The Holy See’s diplomacy in the early years of the 21st century involves more than 175 countries who exchange diplomatic representatives with the Vatican. The Holy See’s permanent representative at the U.N., Archbishop Celestino Migliore, addresses the full range of political, social, economic and cultural issues on the organization’s agenda. Yet when Pope Benedict XVI steps to the U.N. rostrum on April 18, he will do so not as another political power player, but as the voice of universal moral reason. His very presence will be a challenge to those who would separate religious faith from reason (like some radical Islamic jihadists and the Western intellectuals of today’s “new atheism”).

His presence will also challenge those who have lost faith in reason, to the point where they can imagine nothing being “true” always, everywhere and for everyone. In his Regensburg lecture in September 2006, Benedict showed an acute capacity to diagnose the world’s cultural ills, and to put them on the world’s agenda for discussion, in a way that no president, prime minister, king, queen or secretary-general could.

It would have been the bold observer indeed who predicted, 100 years ago, that popes would one day speak to the world — and that the world would listen, and sometimes even change. Yet that is one facet of the story of the 20th-century papacy, which successfully created the moral platform from which Benedict XVI will be speaking when he addresses the world at the United Nations.

(CNS Photo)