Pope Leo XIV’s May 25 encyclical letter Magnifica Humanitas tells the world it is about “Safeguarding the Human Person in the Time of Artificial Intelligence,” but some of its most interesting and important contributions are about Catholic social teaching. 

Magnifica Humanitas is a social encyclical, and Pope Leo consciously places it in continuity with Rerum Novarum. 

That continuity is important because it helps us understand how doctrine—including social doctrine—develops and changes. 

As Pope Leo observes in his much-noted words about slavery, there are moments of “growth” in “the Church’s…understanding [of] the perennial truths of Revelation that she safeguards.”

Before we get to continuity and development, we also have to deal with one other important fact Leo leaves no doubt about—Catholic social teaching is doctrine. 

“When some objected that the Church should not waste energy on worldly matters, but instead focus on communicating the message of eternal life,” Pope Leo writes, we should recall the simple lesson that a serious reading of Scripture and the Tradition affirms.  The “proclamation of the Gospel cannot overlook the concrete lives of people.” 

Too many Catholics today deride Catholic social teaching as an ideology that infects the Church if they do not ignore it altogether. 

Pope Leo, in this exercise of the ordinary papal magisterium that joins his predecessors’, leaves no doubt.  Catholic social teaching is a series of doctrinal claims that bind the Catholic faithful as much as doctrinal claims about eternal life because one is connected to the other. 

Our salvation is not unconnected to how we live.

The most interesting development in Magnifica is the way Leo connects Catholic social teaching to synodality. 

He did it before in 2023, in remarks at The Catholic University of Santo Toribio de Mogrovejo.  Now he has cemented it in the magisterium, writing that “Within this shared task” of bearing witness to justice and fraternity in the world, “pluralism does not dissipate into disorder, but instead, through the practice of synodality, it becomes the space in which humanity rediscovers its solid foundations and its final end.” 

Social doctrine, he tells us, arises from “shared discernment” and so our understanding of Revelation develops.

Among the hardest sayings Leo affirms, though, must be the way he upholds the universal destination of goods.

This is a principle described by John Paul II and Benedict XVI, and its roots are in Aquinas and Scripture. 

It makes many of us uncomfortable because its implications for how we live are vast. 

In John Paul’s words, “God gave the earth to the whole human race,” so, “it is not in accordance with God’s plan to use this gift in such a way that its benefits accrue solely to a select few.”  Private property “is always subordinate” to this principle. 

To put it plainly—hoarding resources and great wealth while others do not have enough is not permitted. Those goods must be redistributed. 

And, Leo joins “immaterial and cultural goods” to more concrete resources, as well as “new forms of property, such as patents, algorithms, digital platforms, technological infrastructure, and data.” 

Magnifica imagines not just a much different material world, but also a much different digital world.

 Already, Silicon Valley has spoken.  For them, Magnifica Humanitas is “false doctrine.”  It will not be accepted. 

That’s not surprising.  For the Gospel to become effective in “the concrete lives of people,” it will depend on the world’s more-than-a-billion Catholics to accept all that Leo and his predecessors have taught.

• Steve Millies is the director of The Bernardin Center at CTU. A political theorist who trained at The Catholic University of America, he taught political science for 15 years at the University of South Carolina Aiken before coming to Catholic Theological Union (Chicago, IL) where he teaches courses in history and Catholic social ethics.