Pope Leo XIV yesterday promulgated Magnifica Humanitas, the first papal encyclical dedicated to the challenge of artificial intelligence, demanding that AI be stripped of what the document calls logics of domination, exclusion and war. Signed at Saint Peter's on 15 May 2026 - the 135th anniversary of Leo XIII's landmark social encyclical Rerum Novarum - the document runs to five substantive chapters and a conclusion, establishing a framework for evaluating AI through the lens of Catholic social teaching. It is the second year of Leo XIV's pontificate.

The timing was deliberate. According to the encyclical, Pope Leo XIII published Rerum Novarum in 1891 when industrial capitalism was reshaping labour and society. His successor draws the parallel explicitly, framing AI as the analogous transformation of the present era - a "change of era" that forces society to confront concentrated technological power much as the industrial age forced confrontation with concentrated economic power.

What the document actually says about AI

The encyclical is careful to avoid treating AI as simply a tool. According to the text, "technology is never neutral, because it takes on the characteristics of those who devise, finance, regulate and use it." This framing has direct consequences for how the document approaches responsibility.

On the technical nature of AI systems, the encyclical is specific. According to Magnifica Humanitas, current AI systems are more "cultivated" than "built," because developers do not directly design every detail but instead create a framework within which the intelligence "grows." This leads to a practical problem: fundamental scientific aspects - including the internal representations and computational processes of these systems - remain, at present, unknown even to those who build them.

The document also challenges the tendency to conflate machine and human intelligence. According to the encyclical, AI systems "merely imitate certain functions of human intelligence" while often surpassing it in speed and computational capacity. What distinguishes human from machine, the text argues, is that AI systems do not undergo experiences, do not possess a body, do not feel joy or pain, do not mature through relationships, and do not know from within what love, work, friendship or responsibility mean. Nor do they possess a moral conscience.

This distinction matters practically. According to the text, so-called AI learning is "a form of statistical adaptation based on data and feedback, which can be very effective, but does not imply inner growth."

The 'disarmament' argument

The document's most striking formulation concerns what it calls the need to "disarm" AI. According to the encyclical, this phrase was chosen deliberately, in full awareness of its force. The gravity of the present moment, Leo XIV said at the Vatican presentation on 25 May 2026, requires words capable of "awakening consciences and indicating paths forward for humanity."

What does disarmament mean in this context? According to the text, disarming AI means "freeing it from the mentality of 'armed' competition, which today is not limited simply to the military context, but is also an economic and cognitive phenomenon." The document describes a race for ever more powerful algorithms and larger datasets driven by geopolitical or commercial dominance. To disarm means, in the encyclical's framing, discrediting the assumption that technical power automatically confers the right to govern.

The nuclear disarmament parallel runs throughout. According to the encyclical, "in a similar sense, artificial intelligence now demands to be 'disarmed,' freed from logics that turn it into an instrument of domination, exclusion or death." The Church's longstanding support for nuclear disarmament provides the rhetorical and moral template.

Autonomous weapons: a direct prohibition

Chapter Five addresses warfare with unusual specificity. According to the encyclical, the Holy See has observed that the growing ease with which autonomous weapons systems can be deployed makes war more "feasible" and less subject to human control. This, the document argues, violates the principle that armed force should be used only as a last resort in cases of legitimate self-defense.

The text goes further. According to Magnifica Humanitas, moral judgment "cannot be reduced to calculation, for it involves conscience, personal responsibility and the recognition of the other as a person." On this basis, "it is not permissible to entrust lethal or otherwise irreversible decisions to artificial systems." No algorithm, the document states, can make war morally acceptable.

Three specific criteria follow. First, the chain of responsibility must be identifiable and verifiable - those who design, train, authorise and employ technology must be held accountable for their decisions. Second, speed and efficiency should never be the supreme motivating force for irreversible decisions made in the context of war. Third, any technology that facilitates attacks without seeing the face of human beings lowers the moral threshold of conflict.

The document also calls for a shared international framework to curb the technological arms race and ensure protection for civilians and the infrastructures necessary for their survival.

Algorithmic exclusion and the governance of platforms

On the civilian use of AI, the encyclical is equally specific. According to the text, important and sensitive decisions - "concerning employment, credit, access to public services or even a person's reputation" - risk being fully delegated to automated systems. These systems, the document notes, "do not know compassion, mercy, forgiveness" and can give rise to new forms of exclusion.

The encyclical addresses the problem of apparent neutrality directly. According to Magnifica Humanitas, when AI systems present themselves as neutral and objective, they end up reflecting and reinforcing the stereotypes or ideological bias of their designers and developers. Entrusting an algorithm in practice with the power to select who is worthy or not, without anyone bearing responsibility for that judgment, means handing over the task of redefining the boundaries of human possibilities.

On platform governance, the text invokes the principle of subsidiarity. According to the encyclical, the highest level in the digital world is not the State, "but rather major economic and technological actors that exercise de facto power over the conditions of everyday life." This level monopolises expertise, data and decision-making authority. Subsidiarity requires that such processes not be imposed from above in an opaque and unilateral manner.

The text also addresses data ownership explicitly. According to the encyclical, "data is the product of many contributors and should not be treated as something to be sold off or entrusted to a select few." It calls for data to be managed as a common or shared good, in a spirit of participation.

The energy and environmental dimension

One section of the document deals with AI's material footprint. According to the encyclical, current AI systems require enormous amounts of energy and water, significantly influencing carbon dioxide emissions, and place heavy demands on natural resources. As the complexity of AI systems increases - especially in the case of large language models - the need for computing power and storage capacity grows, requiring an extensive network of machines, cables, data centres and energy-intensive infrastructure.

The environmental concern connects to the document's broader critique of the technocratic paradigm: the tendency to let the logic of efficiency, control and profit alone shape personal, social and economic decisions. According to Magnifica Humanitas, this paradigm has spread rapidly in recent years, fuelled in part by the expansion of AI, cognitive science, nanotechnology, robotics and biotechnology.

For the marketing and advertising industry, this dimension is not peripheral. Meta's plans for gigawatt-scale AI data centres requiring energy equivalent to millions of American homes - reported by PPC Land in July 2025 - sit directly in the frame the encyclical constructs. When the document says that AI's environmental impact must be regulated and that technological infrastructure is a form of commons, it implicitly addresses the infrastructure choices of the companies that dominate digital advertising.

Work, automation and the dignity of labour

Chapter Four contains a section on work that draws directly on Leo XIII's original concern for industrial workers. According to the encyclical, convergence of automation, robotics and AI is rapidly transforming the very structure of work. The document is sceptical of optimistic framings. It states that "while AI promises to boost productivity by taking over mundane tasks, it frequently forces workers to adapt to the speed and demands of machines, rather than machines being designed to support those who work."

The consequence, according to the encyclical's citation of a Vatican dicastery document from January 2025, is that current approaches to technology "can paradoxically de-skill workers, subject them to automated surveillance and relegate them to rigid and repetitive tasks."

The encyclical also raises the issue of hidden labour. According to the text, a significant part of the digital economy's functioning relies on "the silent work of millions of people engaged in essential yet largely unseen activities, such as data labeling, model training and content moderation, often involving disturbing material." In many cases, these workers are young people, predominantly women, working under demanding conditions for minimal wages.

This is a concern with direct bearing on the advertising technology sector, where data annotation and content moderation underpin the systems that serve and verify programmatic campaigns. The encyclical frames this not as a peripheral issue but as a test of whether the digital economy is built on concealed exploitation.

The transhumanism critique

The encyclical devotes considerable space to what it calls transhumanism and posthumanism - currents of thought that interpret progress as surpassing the human condition. According to the text, these perspectives form the ideological background present in some centres of technological power and occupy the collective imagination through media and social networks.

The distinction the document draws is precise. Transhumanism envisions enhancement of human beings through technologies - biomedicine, body engineering, devices and algorithms - with the aim of increasing performance and capabilities. Posthumanism, especially in more radical forms, challenges anthropocentrism and envisions hybridisation of human beings, machines and the environment.

According to Magnifica Humanitas, the problem is not the use of technology as such but the vision underlying it. "If the human being is treated as something to be perfected or surpassed, it becomes easier to accept that some lives are less useful, less desirable or less worthy."

The encyclical does not name specific companies or individuals, but the framing encompasses currents of thinking visible in Silicon Valley discussions about longevity, cognitive enhancement and the relationship between AI and human intelligence.

What this means for the advertising and marketing industry

The document's relevance to digital marketing is neither obvious nor marginal - it is structural. The encyclical addresses the conditions under which AI-driven systems operate: data concentration, algorithmic decision-making, the governance of platforms, the treatment of workers in data pipelines, and the environmental cost of compute infrastructure.

The EU AI Act's high-risk provisions are directly relevant here. The encyclical's insistence that AI systems affecting employment, credit and access to services must be transparent, contestable and subject to oversight maps closely onto the categories of concern the EU framework targets - categories that include automated advertising systems operating at scale.

The encyclical's treatment of algorithmic manipulation is also pertinent. According to the text, control in the digital age is exercised "not only through explicit prohibitions, but also through the architecture of visibility: what is amplified or rendered invisible, what is rewarded or penalized, ultimately shapes opinions and choices, fostering conformity and self-censorship." This describes, with precision, how recommendation algorithms and ad auction systems function.

The EU's transparency guidelines under Article 50 of the AI Act - which require providers and deployers of generative AI systems to label AI-generated content - were still under consultation in October 2025. The encyclical adds moral weight to the regulatory direction already underway.

At the same time, the document is not a regulatory text and claims no technical expertise. According to the Vatican News account of the presentation event on 25 May 2026, the Church's contribution is not technical expertise but "safeguarding a vision of the human person rooted in dignity, conscience and openness to God." The encyclical positions itself as setting criteria for discernment - criteria that others, including regulators, companies and researchers, are then expected to translate into specific decisions.

Historical significance and the Rerum Novarum parallel

The choice of 15 May 2026 as the publication date was not incidental. Rerum Novarum was published on 15 May 1891, and the encyclical notes that 2026 marks the 135th anniversary of that document. The parallel is structural as well as symbolic.

According to the encyclical, Rerum Novarum addressed the conflict between capital and labour, the question of the workforce, and economic and social transformations driven by industrialisation. It did so not by offering a technical solution but by examining causes and possible solutions in the light of the Gospel and an integral vision of the human person.

Saint John Paul II, the encyclical notes, regarded this approach as a "lasting paradigm" of social doctrine: an exemplary practice through which the Church, when faced with historical changes, exercises her right and duty to examine social realities, make pronouncements about them and indicate paths for finding just solutions.

The five chapters of Magnifica Humanitas follow this template. Chapter One reviews the development of Church social teaching from Leo XIII through Francis. Chapter Two sets out the foundational principles: human dignity, the common good, the universal destination of goods, subsidiarity, solidarity and social justice. Chapter Three examines the technocratic paradigm and what is described as the grandeur of humanity in light of AI's promises. Chapter Four addresses truth, work and freedom in a time of digital transformation. Chapter Five turns to what the encyclical calls the culture of power and the civilisation of love, culminating in the treatment of AI and warfare.

The document cites a 9 February 2026 document from the International Theological Commission, titled Quo vadis, humanitas?, on Christian anthropology and the future of humanity - indicating that the encyclical's preparation incorporated recently published theological reflection on exactly these questions.

Timeline

Summary

Who: Pope Leo XIV, head of the Catholic Church, in his second year of pontificate, supported by the Holy See's theological and doctrinal apparatus including the International Theological Commission and two Vatican dicasteries.

What: Publication of Magnifica Humanitas, an encyclical letter on safeguarding the human person in the time of artificial intelligence. The document calls for AI to be "disarmed" from logics of domination, exclusion and war; prohibits the delegation of lethal decisions to autonomous systems; demands transparency and accountability in algorithmic decision-making; and applies the Church's social teaching principles - human dignity, the common good, subsidiarity and solidarity - to the governance of AI platforms, data and infrastructure.

When: Signed and promulgated on 15 May 2026 at Saint Peter's, the 135th anniversary of Rerum Novarum. Publicly presented on 25 May 2026 in the Vatican's Synod Hall.

Where: Vatican City. The document addresses all Catholic faithful, all Christians and all people of goodwill, explicitly engaging with the global AI governance debate involving governments, technology companies, researchers and international institutions.

Why: According to the encyclical, AI now touches many areas of daily life and affects decisions that shape human coexistence, while also dramatically changing how war is waged. The concentration of AI power in private, often transnational, entities that surpass many governments in resources and capacity requires a framework that is not merely regulatory but rooted in a vision of the human person that no machine can replace.

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