In 2023, world leaders and tech executives gathered in England for the AI Safety Summit, which was the first global conference on artificial intelligence. Two years later, the group reconvened in Paris under a different title: the AI Action Summit. Gone was the emphasis on safety. Lest there be any doubt, U.S. Vice President J.D. Vance told the room: “The AI future is not going to be won by hand-wringing about safety.”

The Trump administration’s cavalier stance on AI, as outlined by Vance in Paris, has largely been defined by its hands-off, deregulatory approach meant to accelerate development. In the global AI race, the United States is effectively the Wild West. Just last week, President Donald Trump’s reversed course and rejected his own administration’s plans to enact a new AI vetting protocol

In 2023, world leaders and tech executives gathered in England for the AI Safety Summit, which was the first global conference on artificial intelligence. Two years later, the group reconvened in Paris under a different title: the AI Action Summit. Gone was the emphasis on safety. Lest there be any doubt, U.S. Vice President J.D. Vance told the room: “The AI future is not going to be won by hand-wringing about safety.”

The Trump administration’s cavalier stance on AI, as outlined by Vance in Paris, has largely been defined by its hands-off, deregulatory approach meant to accelerate development. In the global AI race, the United States is effectively the Wild West. Just last week, President Donald Trump’s reversed course and rejected his own administration’s plans to enact a new AI vetting protocol

Now, however, the administration’s AI policy is meeting its most serious challenger: the first American pope. In a letter released on May 25, Pope Leo XIV asked the world to commit to safeguarding the human person amid rapid AI development—even if it means tapping the brakes.

“Calling for prudence, rigorous evaluation and even, at times, a slower pace in adopting AI does not mean opposing progress; instead, it is an exercise of responsible care for the human family,” Leo wrote. “This need is all the more urgent given the frequent imbalance between the speed of technological growth and the slower development of awareness, norms, safeguards and institutions capable of governing its effects.”

The text, called Magnifica Humanitas, arrives in the form of an encyclical, one of the highest forms of Catholic Church teaching, issued by popes to convey authoritative church teaching on significant matters of doctrine and morals.

It should come as no surprise that Leo dedicated the first encyclical of his papacy to AI. Just two days after his election last May, the Chicago-born pontiff met with the cardinals who elected him and offered some insights into the choice of his name. He recalled his predecessor Pope Leo XIII’s landmark 1891 encyclical, Rerum Novarum, which addressed many of the urgent questions that the world faced during the Industrial Revolution.

Leo XIII took note of what was happening in the world around him: In London, the then-financial center of the world, industry was booming but the divide between the rich and the poor was widening, which led to protests against harsh working conditions. In France, construction on the Eiffel Tower—meant to showcase the heights of human progress—was in full force while the country’s factories were rife with disease from unsafe and unsanitary conditions. And in New York, the Gilded Age’s booming new industries and railroads changed the face of the city and the country, bringing incredible wealth to the hands of a few. At the same time, poverty and desperate housing conditions prompted urgent calls for urban reform.

With all of this in mind, Leo XIII waded into the fray with a document condemning “the enormous fortunes of some few individuals, and the utter poverty of the masses.” In that 1891 letter, he rejected an economic model that concentrated capital in the hands of a select few and supported workers’ rights to fair wages, trade unions, and safer working conditions. “All men are equal; there is here no difference between rich and poor, master and servant, ruler and ruled, ‘for the same is Lord over all,’” he wrote. “No man may with impunity outrage that human dignity which God Himself treats with great reverence.”

It was a revolutionary era, and Leo XIII left no doubt as to whom the church was siding with. Now, more than a century later, another Leo is surveying the world in the face of what he describes as a “fourth industrial revolution” that poses, as he told the cardinals that elected him, “new challenges for the defense of human dignity, justice and labor.”

To be clear, Magnifica Humanitas is not a message of doomerism. It recognizes that AI has incredible potential for economic, educational, and health care benefits. But this will not happen, Leo warned, unless digital infrastructures and algorithms are designed to protect society’s most fragile and offer equitable access to opportunities. The document is clear-eyed about how AI could turbocharge mass job displacement that could eliminate the middle class and deal a serious blow to young people’s futures, how AI data centers can lead to worrisome environmental degradation, and how vulnerable populations are likely to be the most threatened, all under the banner of “progress.”

“Technological innovations, including artificial intelligence, are not neutral, for they can either foster participation and justice or they can exacerbate inequality, control and exclusion,” Leo wrote. “For this reason, they must be evaluated by asking a crucial question: Do they truly help individuals and peoples to become more humane and fraternal, while respecting our common home and future generations?”

In his encyclical, Leo asked world leaders and everyday citizens alike to ensure that new technologies are used for the flourishing of all instead of plowing ahead unheedingly and risking dehumanization. Part of what makes us human, the pope writes, is accepting that human beings have limits and weaknesses. AI, and its pursuit of perfection, control, and automation, risks erasing that.

“Humanity flourishes not despite limitations, but often through them,” the pope writes—reminding readers that some of the world’s greatest art and music attests to this reality, as do the hard fought victories of the Civil Rights movement and ending apartheid.

For almost a decade now, the Vatican has been engaging with some of the ethical questions related to AI, and, in 2020, it brought together major leaders from companies like Microsoft, Cisco, and IBM to sign an agreement committing to AI development buttressed on the principle of human dignity and guided by transparency, accountability, and inclusion. In 2023, Pope Francis called for a binding international treaty to regulate AI and warned of a “technological dictatorship” threatening humanity. In 2024, he made history as the first pope to address a G-7 summit, where he dedicated his remarks to AI and called for a ban on lethal autonomous weapons.

At the encyclical’s recent launch event at the Vatican, Leo was joined by Christopher Olah, co-founder of Anthropic, who candidly admitted that tech companies, like his own, are motivated by profit, geopolitical pressure, and pride. “We need informed critics who will tell the labs when we are failing,” he said. “We need moral voices that the incentives cannot bend.”

In his new encyclical, Leo built on what his predecessors—both Leo XIII and Francis—said by naming AI development as one of the most urgent moral issues of our time, and he urged extreme caution and reflection on how the world moves forward.

The pope is clear that neither he, nor the Catholic Church, is offering specific policy proposals, but rather offering moral principles for consideration. But at the same time, his letter is clearly nudging governments and other international institutions to lead the way in enacting new regulations to mitigate the AI risks that he warns about in the encyclical. It was a conversation started at the Vatican this week, but it’s already informing discussions from the likes of the European Commission to the high-takes California governor’s race. Silicon Valley has effectively been put on notice.

Just days before the document’s release, Trump was all set to sign an executive order that would have required the federal government to evaluate AI models before their release—only to change his mind at the last second and declare that it “gets in the way” of development. “We’re leading China, we’re leading everybody, and I don’t want to do anything that’s going to get in the way of that lead,” Trump said.

Trump’s approach to AI development is likely to once again put his administration in direct conflict with Leo; in April, Leo’s calls for an end to the war in Iran led to a barrage of attacks by Trump. At a White House press briefing in May, Vance—a recent convert to Roman Catholicism—said that he looked forward to reading the pope’s encyclical. “I’m sure it will contain a lot of insights, some of which I’ll probably agree with, some of which I may not, but I think that it’s going to be a very, very important document,” Vance said. “My guess is it’s going to have a lot of influence.”

Considering that Rerum Novarum helped inspire the framework for U.S. President Franklin D. Roosevelt’s New Deal and motivated Poland’s Solidarity Movement, which brought an end to the country’s communist rule, that’s a good bet.