Pope Leo XIV yesterday called for robust regulation of artificial intelligence and for its developers to work for the common good rather than profit, issuing a sweeping manifesto on safeguarding humankind as the technology impacts everything from work to war.

Magnifica Humanitas (Magnificent Humanity), Leo’s first encyclical, has been eagerly awaited ever since history’s first United States-born pope announced, days after his election, that he considered AI to be the biggest challenge facing humanity today.

In the text, Leo denounced the “culture of power” driving the AI race, especially in developing ever more sophisticated methods of remote warfare. He declared that it was “not permissible” to entrust irreversible, lethal decisions to AI systems, setting up another flashpoint between the American pope and the Trump administration, which has worked aggressively to deregulate AI development.