In a landmark encyclical titled “Magnificent Humanity,” Pope Leo has issued a stern warning regarding the rapid, unchecked development of artificial intelligence. The pontiff cautioned that current AI trajectories risk fueling global misinformation and perpetuating unending cycles of conflict. Highlighting the dangers of autonomous weaponry, the Pope noted that some systems have already advanced beyond the capacity for effective human governance, urging world leaders to implement robust legal frameworks and independent oversight to mitigate these existential risks.

Beyond the technological sphere, the document marks a significant shift in Church teaching by formally repudiating the “just war” theory, a doctrine that has historically been used to justify military intervention. Pope Leo argued that the concept is outdated and that the reliance on force and violence consistently results in catastrophic consequences for civilian populations. He further warned that political leaders may be tempted to utilize armed conflict as a cynical distraction from domestic challenges, calling for a more active political engagement to prioritize peace over the profits of the arms industry.

Addressing the human cost of the digital age, the Pope also drew parallels between historical injustices and modern labor practices. He decried the “new forms of slavery” faced by workers in the supply chains for rare earth elements and hardware production, noting that the physical toll on these laborers sustains the global demand for computational power. In a moment of historical reflection, the Pope also offered a formal apology for the Church’s delayed condemnation of transatlantic slavery, labeling it a deep wound in Christian history.

Concluding his 43,000-word encyclical, Pope Leo called for a collective effort to abandon the pursuit of technological dominance at the expense of human dignity. He urged both policymakers and the public to reject the notion that these problems are too vast to solve, emphasizing that every individual bears a responsibility to act. The event, which featured insights from Anthropic co-founder Chris Olah, underscored the growing consensus that frontier AI labs must operate under stricter ethical constraints to ensure that technological progress serves the common good.