Pope Leo's first encyclical of his papacy asserted that artificial intelligence is not inherently immoral, but that its adoption should be slowed to enable the development of moral guardrails and it gleaned strong approval from ecumenical groups.

"Artificial intelligence already touches many areas of our lives and affects decisions that shape human coexistence," the pontiff said at the Vatican while he observed that AI is also "dramatically changing how war is waged."

According to the Roman Catholic site, Papal Encyclicals, "A papal Encyclical is the name typically given to a letter written by a pope to a particular audience of bishops."

It says this audience of bishops may be all of the bishops in a specific country or all bishops in all countries.

Peter Prove, director of the World Council of Churches' international affairs commission, posted on LinkedIn, "This first encyclical by Pope Leo XIV is an incredibly important initiative in addressing the transformative technology of our age, #artificialintelligence #AI.

"This technology - at least Artificial General Intelligence #AGI - should have been developed in the equivalent of a level 4 biohazard facility," he said.

Prove noted, however, the titans of this industry are "almost all man-children 'on the spectrum', without empathy or wisdom - just different degrees of evil."

"Enter the spiritual wisdom, empathy and maturity of Pope Leo. Let's see if he can help slow down this mad rush into the unknown."

Rev. James Martin, a Jesuit priest, wrote in America Magazine, the Jesuit Review, that he is a capitalist.

"As a graduate of the Wharton School of the University of Pennsylvania who studied finance, accounting and economics (and worked in corporate finance before entering the Jesuits), I believe that capitalism is the economic system that most efficiently distributes goods and services."

"Pope Leo XIV's superb new encyclical, 'Magnifica Humanitas,' is the most cogent Catholic critique of capitalism that I have ever read.

          - 'DEFT, LUCID STROKES'

"Pope Leo does this in sure, deft and lucid strokes. (And it's clear that an English-speaker wrote this encyclical and that it was not simply translated into English. It's beautifully written."

In another piece on the encyclical, for Geneva-based Globe Ethics, its Germany-based president, Rev. Dietrich Werner, explained how it connects to a broader global call for ethical AI governance.

He said that the Roman Catholic Church enters as a "civilisational voice," seeking to place ethical limits on the accelerating transformation of humanity itself, rather than as a technical actor or merely a cautious observer.

Werner noted that the message invites religious communities, philosophers, scientists, policymakers, educators, and civil society institutions to join the conversation.

"Importantly, this invitation extends beyond Christianity. Jewish, Muslim, Buddhist, Hindu, and secular humanist traditions all possess ethical resources relevant to questions of technological power, human dignity, responsibility, and social justice," said Werner.

"The deeper significance of the encyclical may lie not in offering definitive technical solutions, but in reminding the world that the central question of the AI age is not simply what machines can do, but what human beings should become."

Werner said humanity has to remain "morally greater" than the systems it conceives.