Glen Weyl, the Princeton-Harvard-Microsoft whiz kid economist, has declared Pope Leo XIV “perhaps the single most important person in the world on AI at this moment.”

He is not alone in the estimation. A lollapalooza of tech bros and allied Silicon Valley types have turned their eyes toward Rome since Leo became pope in 2025, culminating in Christopher Olah, co-founder of AI leader Anthropic being front and centre at the presentation of Magnifica Humanitas this week. To read the first American born pontiff’s inaugural encyclical is to understand why.

Media coverage of the Holy Father’s cautionary words about AI’s advent has understandably focused on the central metaphor he deploys: the contrast between the Tower of Babel and the rebuilding of Jerusalem. 

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The powerful image crystallizes Leo’s expressed concern about the “profound” threat of AI should it arise, like Babel, “without reference to God, supported by a uniformity that eliminated diversity and chose homogenization over communion… (and) however grandiose, arises from self-affirmation, sacrifices human dignity for efficiency and aspires to reach heaven without God’s blessing.” 

By contrast, the rebuilding of Jerusalem after the return from Babylonian captivity models “an undertaking with God at the center, which rebuilds relationships before rebuilding with stones. Jerusalem rediscovers…the harmony that arises when all persons assume their own role and recognize that their strength comes from the Lord.”

The message could not be clearer even for the micro-attention span audience that customarily wades only in the shallow end of the Tik-Tok cesspool. AI is a choice. It exists among the manifold “new things” homo sapiens has chosen over its 300,000-year history. We can choose wisely for good by making it a shared tool for the common weal. Or we can tempt evil by recklessly letting it become a weapon exclusive to the already powerful.

In that careful framing, Leo XIV consciously builds his own encyclical edifice on the foundations of his “beloved predecessor” Leo XIII’s 1891 encyclical Rerum Novarum (“New Things”). In so doing, he not only acknowledges his authorial debt to Leo XIII, but also his intentional continuity with 135 years of Catholic social teaching.

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The emphasis on continuity is crucial when AI is being credibly touted as a radical departure for human existence. Its conundrums are, in fact, different only in degree, not in kind, from those facing humanity when Rerum Novarum was written. Our tools evolve. We remain the “poor banished children of Eve.”

Rerum Novarum excoriated the industrial age’s “small number of very rich men (who) have been able to lay upon the teeming masses of the laboring poor a yoke little better than that of slavery itself.” Yet it also debunked as impotent and unjust contemporary socialist calls for the abolition of private property: “Every man has by nature the right to possess property as his own. This is one of the chief points of distinction between man and the animal creation.” 

With those words, Leo XIII placed at the heart of Catholic social teaching heightened awareness of ambiguity and so a complementary imperative for discernment. Leo XIV’s new encyclical follows faithfully in that tradition. It tucks into its large, shining metaphor of Babel versus Jerusalem four small words: “the ambiguity of tools.” It’s a simultaneously delightful and ominous phrase that encapsulates the encyclical’s intention.

“Each phase of progress has also revealed the ambiguity of tools that can cause harm when not oriented toward the good,” Pope Leo writes. “This complicates the assessment of…the long-term effects they may have on both the dignity of individuals and the common good.”

Attention will rightly go to his subsequent call for regulation of AI to ensure its harms are minimized and its benefits serve maximal good. What must not be missed is his immediate qualifier: “The issue is not limited to regulation.”

What is essential, he stresses, is a “shared discernment process,” not just to set rules to thwart threats but to undertake serious identification of “the spiritual and cultural roots of ongoing transformations.” AI is only the latest example.

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As he adds: “If we focus only on contingencies, we risk letting the succession of emergencies dictate the direction of our path… crucial questions impose themselves on our conscience and can no longer be avoided….”

Happily, Catholic social teaching, indeed Holy Mother Church herself, offers a proven answer in the Way, Truth and Light. Little wonder at least some in the lollapalooza of whiz kid tech bros are turning their minds toward it in their quest for guidance.