Pope Leo calls for AI to be ‘disarmed’, apologises for Catholic’s role in legitimising slavery

“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. It is not enough to invoke ethics in the abstract; robust legal frameworks, independent oversight, informed users and a political system that does not abdicate its responsibility are required. Otherwise, change will be governed only by technocratic thinking and presented as necessary and inevitable, ultimately imposing rules shaped by those who control data, infrastructure and computing power.”

Olah acknowledged that AI labs including his own operated “inside a set of incentives and constraints that can sometimes conflict with doing the right thing.”

“The pressure to stay commercially viable and to stay at the research frontier. Geopolitical pressure. And the older, plainer pressures of pride and ambition. No matter how sincerely any of us intend to do the right thing — and I believe many of us do — we will always be influenced by those incentives,” he said.

“That is why, if we want this technology to go well, it is enormously important that there be people outside those incentives — people who care about things going well and insist on safety, who are paying close attention, who are willing to say hard things, who are willing to be our earnest, thoughtful, critics.”

Leo also wrote the Catholic Church’s centuries-old “just war” theory “which has all too often been used to justify any kind of war, is now outdated.”

The “just war” doctrine has been invoked by Trump administration officials including vice-president JD Vance and defence secretary Pete Hegseth to defend the US attack on Iran.

“Humanity possesses far more effective and capable tools for promoting human life and resolving conflicts, such as dialogue, diplomacy and forgiveness. The use of force, violence and weapons reflects a relational poverty that always has disastrous consequences for civilian populations,” the pope said.

The document also called it “not permissible” to entrust lethal decisions to AI systems.

“AI does not remove the intrinsic inhumanity of conflict; indeed it can only bring about conflict more quickly and render it more impersonal, lowering the threshold for resorting to violence, transforming defense into threat prediction and thus reducing victims to data,” the encyclical says. “In this way, it will accustom us to the idea that violence is inevitable and needs only to be optimised.”

Leo also made what the media described as the first explicit papal apology for the Holy See’s role in legitimising slavery, writing that the Vatican’s record “constitutes a wound in Christian memory” and “one from which we cannot consider ourselves detached.”

“It is true that past events cannot be judged anachronistically, as though the moral criteria that matured over time had always been available. Yet neither can we deny or diminish the delay with which both society and the Church came to denounce the scourge of slavery,” he wrote.

“It is impossible not to feel deep sorrow when contemplating the immense suffering and humiliation endured by so many in stark contrast to their immeasurable dignity as persons,” he added. “For this, in the name of the Church, I sincerely ask for pardon.”

The document was signed on 15 May, the 135th anniversary of Leo XIII’s “Rerum Novarum,” a landmark 19th century papal document that defended workers’ rights during the Industrial Revolution, The New York Times noted.