Pope Leo XIV has issued a stark warning over the dangers of artificial intelligence, cautioning that some AI-powered weapons systems may soon become impossible for humans to control.
The pope delivered the warning while unveiling his highly anticipated manifesto on artificial intelligence titled Magnifica Humanitas (“Magnificent Humanity”) at the Vatican on Tuesday.
In the landmark encyclical, Leo raised alarm over the rapid rise of autonomous military technology and warned against allowing lethal decisions to be handed over to machines.
“Very troubling voices have reached me about increasingly autonomous weapons systems practically beyond any human reach to govern effectively,” he said.
The first American pope also criticised what he described as a global race for increasingly powerful AI algorithms and massive data systems driven by geopolitical and commercial competition.
Leo stressed that the Catholic Church wants to work alongside AI developers to ensure technology remains ethical, human-centred and properly regulated.
Among those attending the Vatican presentation was Christopher Olah, co-founder of AI company Anthropic, which has publicly opposed the use of artificial intelligence for lethal autonomous warfare and mass surveillance.
Olah acknowledged that AI companies often operate under pressure from commercial incentives that may conflict with ethical decision-making.
“The questions raised by AI are bigger than the AI research community,” he said, welcoming outside voices such as the Church to help guide future development.
In the encyclical, Leo directly criticised the use of religion to justify modern warfare and appeared to challenge recent arguments linked to the Trump administration’s interpretation of “just war” theory.
He described the centuries-old doctrine as “outdated” and insisted that “no algorithm can make war morally acceptable”.
The pope warned that AI should never dominate humanity and said technology must remain accessible, transparent and open to public debate.
“Disarming AI means freeing it from the mentality of armed competition,” he wrote.
“To disarm does not mean rejecting technology, but preventing it from dominating humanity.”
Leo also highlighted the hidden human cost behind AI development, pointing to exploited workers, traumatised content moderators and children involved in mining rare earth materials used in technology production.
“Nothing in the world of AI is immaterial or magical,” he warned.
The pope argued that efficiency and innovation should never justify exploitation or environmental destruction, urging stronger protections for workers and the planet.
The manifesto additionally included a historic apology from the Vatican over the Catholic Church’s past role in the slave trade and the justification of slavery.
“For this, in the name of the Church, I sincerely ask for pardon,” Leo wrote.
The release of Magnifica Humanitas follows years of Vatican research into AI ethics and expands on earlier Church initiatives such as the 2020 “Rome Appeal for an AI Ethic”.
Experts believe the manifesto could become one of the most influential Church documents in recent decades, similar to Pope Francis’s climate-focused encyclical Laudato Si’, which reshaped global conversations on environmental responsibility.
The United Nations estimates AI could become a £3.56 trillion industry by 2033, intensifying worldwide debate over who controls the technology and how it should be governed.
