Babel, Nehemiah and algorithms: A guide to key terms in Pope Leo’s new encyclical on AI

(OSV News) — What do the Tower of Babel, the biblical figure Nehemiah, algorithms and realpolitik have in common?

They’re all discussed — along with integral human development, the technocratic paradigm and Catholic social teaching — in Pope Leo XIV’s first encyclical, “Magnifica Humanitas: On Safeguarding the Human Person in the Time of Artificial Intelligence.”

The highly anticipated text, signed by the pope on May 15 and released May 25, invokes the wisdom of the Church’s social teaching as a framework for shaping AI amid rapid technological advances, a fractured global landscape and accelerating threats to human life and dignity.

Here’s a guide to some of the terms discussed in the document.

Artificial intelligence: An umbrella term for technology that emulates human intelligence. The ability to learn from data, recognize patterns, solve problems, make decisions and generate original content from human prompts are all features of AI.

In “Magnifica Humanitas,” Pope Leo writes that “it is not possible to provide a single, comprehensive definition of AI.”

“What can be stated, however, is that we must avoid the misconception of equating this type of ‘intelligence’ with that of human beings,” he continued. “These systems merely imitate certain functions of human intelligence. In doing so, they often surpass human intelligence in speed and computational capacity, offering tangible benefits across many fields. Yet this power remains entirely tied to data processing.”

AI is programmed in several computer languages, among them Python, C++, Java and R. Everyday examples of AI in action include various types of chatbots such as OpenAI’s ChatGPT and Anthropic’s Claude, online product recommendations and virtual personal assistants like Amazon’s Alexa and Apple’s Siri. AI has a range of business applications across almost all market sectors, including healthcare, education, energy and security.
Algorithm: In essence, a routine, step-by-step process for accomplishing a task. AI algorithms, which are more complex, are designed to cover multiple “what ifs?” in a given situation, and to learn from data on which they are trained. Pope Leo cautions in his encyclical that AI algorithms can be used to exert dominance over the vulnerable and over humanity itself, while eroding responsibility and empathy.

“From this follows a simple but compelling consequence: we cannot consider AI to be morally neutral,” he writes. “In reality, every technical tool embodies choices and priorities through what it measures, ignores and optimizes, and how it classifies people and situations.”
Alignment: In AI development, the process of ensuring the technology squares with human values, so that AI models safely serve human interests. “Emergent misalignment,” where AI deviates from such norms and behaves detrimentally, is a growing concern among AI ethicists and theologians. Pope Leo insists that alignment come with a further condition: “the possibility of openly discussing the ethical frameworks involved and subjecting them to shared standards of social justice. Otherwise, those who control AI will impose their own moral vision, which will become the invisible infrastructure of these systems.”
Babel, Tower of Babel: Described in Genesis 11:1-9, the city and tower built by the nations of the earth in the valley of Shinar, after Noah and his family survived the flood. Because the nations, which spoke the same language, undertook the project in human pride, the Lord confused their speech, leading to division and dispersion across the earth. In section seven of his encyclical, Pope Leo uses this example to show “the limits of any effort that, however grandiose, arises from self-affirmation, sacrifices human dignity for efficiency, and aspires to reach heaven without God’s blessing.”
Catholic social teaching (social doctrine): The Church’s teaching — which draws on papal, conciliar and Church documents — on the means of building a just society and living out holiness in modern life. As Pope Leo explains in his encyclical, the term was coined by Pope Pius XII in 1950, but owes its development to “a long tradition of ecclesial reflection on life in society, rooted in Sacred Scripture, the Church Fathers and the theological and legal developments of the Middle Ages and modern era.” Pope Leo also notes that his “beloved predecessor” Pope Leo XIII propelled that tradition toward modern applications in his 1891 encyclical “Rerum Novarum.”

Key principles of Catholic social teaching are the common good; the universal destination of goods, which holds that the goods of creation are meant for all (even when private property is justly acquired); subsidiarity, which stresses that society’s larger institutions, including the state, should not overwhelm or interfere with smaller ones (including families and Church communities); solidarity, which holds that humanity, even with its differences, is a family; and justice, which the Catechism of the Catholic Church says “consists in the constant and firm will to give their due to God and neighbor.”

In his encyclical, Pope Leo stresses that AI and its attendant power must be assessed against the principals of Catholic social teaching.
City of God, city of man: Symbols, respectively, of faith in God and unbelief. The two are contrasted by St. Augustine in his work best known as “The City of God.” In his encyclical, Pope Leo (a member of the Order of St. Augustine who regularly invokes the saint’s thought) cites the image and quotes St. Augustine’s observation that “two loves have built two cities: the earthly city, the love of self even to the contempt of God; the heavenly city, the love of God even to the contempt of self.” Pope Leo then reflects, “As throughout history, these two loves continue to contend for dominance in our hearts today. The age of AI is no exception: the construction of Babel or the rebuilding of Jerusalem begins within each one of us.”
Ecology of communication: A model for understanding the dynamic between communications and the social order. The concept, sometimes called “media ecology,” traces its roots to communications scholarship from the 1960s. In his encyclical, Pope Leo uses the term in calling for, among other things, transparency in Church communications, personal data protection and content selection; digital and media literacy; serious journalism; information verification; and the enhancement of critical thinking skills. Pope Leo notes that such actions reflect “the fundamental principle” that “truth is a common good and not the property of those with power and influence.”
Integral human development: A term found in St. Paul VI’s 1967 encyclical “Populorum Progressio” that views the flourishing of individuals and peoples holistically — taking into account spiritual, cultural, moral and relational concerns, with an eye not only to present but future generations. The concept is central to Catholic social teaching (see above), with Pope Francis establishing the Vatican’s Dicastery for Promoting Integral Human Development in 2016. In his encyclical, Pope Leo describes integral human development as “the framework through which we can interpret the changes of our time, including those brought about by the digital revolution.”
Large language model: A type of AI model capable of being trained to understand and generate language in a human-like way, with context and nuance.
Multilateralism: In international relations, the concept of cooperation among diverse nations. Originally a geometry term for “many-sided,” multilateralism is central to entities such as the United Nations, and to international agreements on a rules-based order that safeguards human life and dignity. In his encyclical, Pope Leo points to a crisis in the current multilateral system, not only due to “structural limitations” but to “a frequent lack of shared will to support and reform them, or to recognize their moral authority.”

He observes that the economic globalization following the collapse of Europe’s communist regimes in 1989 is far from “genuine multilateralism.” Instead, he writes globalization’s “almost blind faith in markets” has “provoked fundamentalist, identity-based and nationalistic reactions” and devolved into “a disorderly and conflict-ridden multipolarism with a prevailing sense of mistrust.” Shared efforts for a common good are further imperiled by reemerging attempts to “forge a collective identity in opposition to an enemy,” with each side claiming itself to be “a victim entitled to retribution” and replacing international law with the claim that “might makes right.” As a result, warns Pope Leo, power politics are sidelining peacebuilding initiatives and compromising “the achievements of humanitarian law,” with protections for civilians and “especially children” amid conflict “regarded as naïve relics of the past.”
Nehemiah: Both the name of the governor of Judah and the book found in the Bible. In about 444 B.C., Nehemiah was granted permission from Persian King Artaxerxes I to return to Jerusalem — where some Jews, following the sixth-century B.C. Babylonian exile, had begun to resettle — in order to rally and direct the people in a shared restoration of their ancient city. Unlike Babel, said Pope Leo in his encyclical, this effort under Nehemiah (and later under Ezra) placed “God at the center” and prioritized “communion” and “rebuilding relationships” over “uniformity.”
Political realism, realpolitik: Political realism is a political theory that prioritizes power over morals and ethics, effectively holding that “might makes right.” In international relations, realpolitik (a term first popularized in the 19th century) also privileges power, as well as national interest, over other principles and considerations, framing it as pragmatic politics. In his encyclical, Pope Leo warns that both philosophies — the latter of which he condemns as “truly irresponsible” — work to present war as inevitable, thereby precluding genuine peace based on justice and charity.
Technocratic paradigm: A term also used by Pope Francis in his 2015 encyclical “Laudato Si’” to describe a worldview in which humanity employs technology with the guiding aim of “possession, mastery and transformation,” rather than the humble, grateful stewardship of God’s abundant gifts.

Pope Leo writes that this “pervasive technocratic paradigm … amplified by the digital revolution and AI, threatens to normalize an anti-human vision. In that vision, the fullness of life is equated with having more, reducing weakness, eliminating uncertainty and exerting total control. When efficiency becomes the ultimate measure of value, human beings are tempted to see themselves as a project to be optimized rather than as persons called to relationship and communion.”
Transhumanist, posthumanist: Transhumanism holds that humans can transcend their limitations particularly through scientific advances such as computer technology, cryonic preservation, biomedicine and other technological interventions. Posthumanism counters the view that humans are central, with some posthumanists advocating a hybridization of humans, machines and the environment.

“Even when such ideas remain largely speculative, they gain relevance by altering the collective imagination and thereby influence social, economic and political choices,” Pope Leo writes in his encyclical.

He contrasts these views with the Christian understanding of humanity as created by God, noting that human limitations are vital opportunities to “recognize the inviolable dignity of every person,” live with compassion and “encounter the presence of the Lord.”