On November 19, 1848, a Catholic priest from a poor village in the far west of Germany ascended to the pulpit of Mainz Cathedral. Looking out into the ancient church, he spoke on new controversies; on the great changes convulsing Europe, the political upheaval spreading talk of democracy to every corner of the continent, and the nascent Industrial Revolution driving people from farm to factory – and into destitution. The homilies of that “farmers’ priest,” Wilhelm Ketteler, given across the Advent season, are remembered as a watershed in the Christian response to the crises of modernity. Ketteler himself went down in history as the “Father of Catholic Social Thought.” It was a status the thirty-seven-year-old pastor never sought – and would never have expected.

Ketteler, ordained only four years prior to his Advent sermons, had tried to stay well away from politics. But politics wouldn’t stay away from him. After the March Revolution – marked in Mainz by the deposition of the ruling Grand Duke – Ketteler’s confessor asked the priest to stand as a candidate for the national assembly the reformers had convened for May of that year. Ketteler begged him to reconsider. His confessor persisted. Ketteler stood in the election – and won spectacularly. A lone vote fell to the vice-rector of Münster seminary; a biographer suspects Ketteler had voted against himself. On May 14 he traveled east to Frankfurt, where the assembly was meeting. There he would meet radicals who wanted a unified democratic republic, an echt Deutsch version of the French Revolution; conservatives who wanted to preserve the old regime; and liberal reformers attempting to chart a path between the two. Ketteler hoped to win recognition of popular sovereignty and protect the rights of the Catholic Church in the new Germany in the making.

Taking a parliamentary seat, Ketteler quickly discovered unexpected fame paired with his unwanted power. In September, a split between radical and moderate reformers sparked an uprising on the streets of Frankfurt. On the night of September 18, two unarmed conservative deputies were murdered by a pro-radical mob. Ketteler saw the victims’ corpses in the hospital, looking as if, he wrote, they had been “ripped apart by the teeth and claws of wild animals.” At the funeral he gave an oration: in the murders, he said, we can glimpse the struggle between “the highest ideals that the human soul can conceive” and “the burgeoning of passions so base that they have hardly ever occurred in humanity.” The young priest gained a national profile almost overnight.

When Ketteler returned to Mainz in November he found the activity that would lead to 1848 being remembered as the “springtime of nations” in full swing. Almost three thousand men and sixteen hundred women were members of democratic organizations, and many more signed up to the new trade unions that sprung from the barricades of March. The most radical activists, represented by Karl Marx and Friedrich Engels’ Communist Manifesto, spoke of a new society, defined by common property and human fellowship; even the most moderate liberals expected sweeping constitutional reforms. Here was the seedbed, historians argue, of the movements that would define modern European history, the entry of the laboring poor onto the political stage.

But the springtime passed not to summer, but winter. Panic among elites, with regrouped military forces, prompted state repression: in Paris, three thousand workers were killed, in Habsburg territories roughly five thousand revolutionaries were imprisoned, and in Germany a generation of activists vanished into exile in England and America. By the close of the year, nearly everywhere on the continent, every old ruler had been restored to power. When Marx looked back in 1852, he reflected, “Society seems now to have retreated to behind its starting point.” The laboring poor slipped back to the margins.

Out of sight isn’t out of mind, though, at least not for Ketteler. When he took to the pulpit at Mainz Cathedral to address the “social question,” the priest-politician was known as a reformer, not a rabble-rouser. And his perspective doesn’t seem to share much with the anticlerical socialist thinkers of the time – Marx and Engels, whose Communist Manifesto Ketteler had read, or their French rival Pierre-Joseph Proudhon – who saw 1848 as an occasion to denounce the growing capitalist system. You might expect a priest in his position to make a full-throated defense of the existing order, uphold private property rights, and warn of the perils of revolution. Ketteler didn’t.

The social question – both high ideals and base passions – only has an answer, he says, in Christ. But Christ makes demands upon us: above all to “Love thy neighbor as thyself.” How can you love someone, Ketteler wonders, while they hunger and thirst because of you? He doesn’t denounce the radical critics of private property; he agrees with them. He paraphrases the Church Father Basil the Great, warning that those who withhold goods from those in need are no less thieves than those who steal another’s goods.

Therefore, Ketteler states, “the false teaching of a rigid right to property is a constant sin against nature.” “It declares,” he says, “a constant theft for a right.” He says the Catholic Church “sanctifies communism, in that it turns the fruits of property once more into the common goods of all.” He tackles Proudhon’s still oft-quoted adage “property is theft” head on. He says that it’s not “merely a lie, it contains … a fearful truth.” The only way of combating it is to “destroy the truth in it.” The Christian right to property “has nothing in common” with the prevailing “godless right to private property” which leaves “poor brothers to languish from want of the necessities.” No Christian could endorse a system that permits this.

How can you love someone, Ketteler wonders, while they hunger and thirst because of you?

Certainly, Ketteler argues – following Saint Thomas Aquinas – we have a right to property, given to us by God for our sustenance. But we are, Ketteler suggests, not so much owners as temporary guardians of the gifts of God. And given that we are stewards, not owners, we are obligated to use property as God wills us to use it: to satisfy every human being’s material needs. Where Ketteler parts company with contemporary socialists, he suggests, isn’t so much over the ends but in the means. Self-sacrificing love ought to motivate us to give up everything for our neighbor – not fear of the police inspector.

Ketteler’s Advent sermons are distinctly skeptical of the role of the state. His intervention – announcing what he sees as the truths of the church – was careful not to identify the church with government policies. Ketteler did not stand at the pulpit to profess a program. He called for spiritual renewal: “I’m not afraid of social evils,” he told the Mainz faithful: “I am only afraid of godlessness, faithlessness, Christlessness!” The crux of the social question, for Ketteler, is to be found in the indifference of Christians to the suffering of the poor, and in the refusal of the church to live out her faith in works of love. If Christians choose to live as Christ did, he thought, the injustices inflicted upon the poor will be swept away. Spiritual and social transformation are one. The stated aim of his first homily sums up his perspective: “One soul, one life won today for Jesus Christ and the consolation of the poor!”

Ketteler addresses his appeal to wealthy Christians and those who, like himself, were born to noble families. Heroic acts of individual charity could make a just economic system possible without the iron fist of a potentially absolutist state. But what Ketteler says sets him apart from earlier Christian critiques of capitalism – the “Christian Socialism” Marx and Engels had derided as “the holy water with which the priest consecrates the heart-burnings of the aristocrat.” The rich are called to give, Ketteler says, but the poor are chosen to be Christ’s apostles, just as they were two millennia ago. Apostles don’t simply receive charity: they build the kingdom with their own hands.

At the time, Ketteler himself may not have realized the import of his words. Over the next few decades, as the German labor movement spread in tandem with the Industrial Revolution, the poor were at work, organizing. By the 1860s, while Otto von Bismarck prepared to unify Germany’s disparate states into one mighty empire, the laboring poor had begun to unite as never before. Under the leadership of the Jewish-atheist lawyer Ferdinand Lassalle, who founded the world’s first working-class political party in 1863, the General German Workers’ Association, labor activists from across the country had begun to make political demands: universal suffrage and the legal right to a fair wage.

Ketteler – who had been appointed Bishop of Mainz in 1850 – wasn’t the one speaking any more. He listened instead. In the 1860s, Ketteler began a correspondence with Lassalle, in 1864 writing a book inspired by the younger man’s ideas, The Workers’ Question and Christianity, in which Ketteler condemns the liberal economic order in the most profound terms. He states bluntly, “In paganism work was the affair of slaves, and without doubt the entire working class would resume this position, if it were possible to recast the world according to ideas of paganism.” The bishop thought that one of Lassalle’s key ideas, the establishment of worker-run industries, had much in common with the principles of Catholic teaching. Such cooperatives, Ketteler wrote, would see laborers sharing the profits made from their products, escaping the poverty wages of “the slave market of liberal Europe.” He’s less sanguine than Lassalle about the role state funding could play – hoping for the philanthropy of wealthy Christians. But he doesn’t count on it. The will of God precedes the rights of the propertied. If the rich are called to love, the poor are called to seek justice.

The right of workers to organize rests, he says, “upon the divine order and is essentially Christian.” That many trade unionists are atheists shouldn’t dissuade Christians from joining trade unions, he said; that atheists breathe the same air as us does not compel us to asphyxiate. Five years later, in an acclaimed speech at Liebfrauenheide, he doubled down. The bishop praised English trade unions, then striking for higher pay, a demand, he said, “of justice and of Christianity.” Living wages, rest days, and the prohibition of child labor are all goals arising from the basic teachings of the church, Ketteler said. In the exercise of their private property, employers had no right to deny their workers these basics. “The godlessness of capital, which exploits the worker as labor power and as a machine up until he is destroyed,” Ketteler tells his audience, “must be crushed.”

Germany’s nascent socialist movement should be applauded for campaigning for these causes, Ketteler added – singling out the work of the organizer Friedrich Fritzsche, a militant secularist. The same year, he wrote a report for the Conference of German Bishops at Fulda, requesting that each diocese appoint a specialist assigned to “study the state of the working class.” A priest wrote to him later, “Coming from lips other than yours, our Catholic bourgeoisie would not be able to stand hearing such truths.”

In years of patient work after his homilies of 1848, Ketteler helped effect a sea change in the church’s response to social injustice. Across Germany, lay associations, dioceses, and religious orders organized campaigning groups, trade unions, and worker’s cooperatives. The increasing militancy of Christian groups didn’t go unnoticed by the secular – and often anticlerical – left. In one 1869 letter Marx wrote to Engels, he told his collaborator that “the priests … must be energetically attacked. The curs (e.g., Bishop Ketteler in Mainz …) are flirting, where they find it suitable, with the workers’ question.” If Marx had little time for Bishop Ketteler, the feeling wasn’t mutual: it’s said that the bishop, traveling to the first Vatican Council in 1870, took Marx’s Das Kapital with him to read on the train.

Ketteler’s ideas on the social purpose of property – and the corresponding right of workers to collective action in pursuit of just wages – spread among Catholics worldwide. In Italy and in Austria, bishops like Giacomo Radini-Tedeschi and organizations like the Austrian Christian Social Party were inspired by their German confrere’s work to encourage Catholics to form trade unions. Later that century in England, Cardinal Henry Manning took Ketteler’s thought to the picket line, playing a pivotal role in the Great Dock Strike of 1889.

In 1877, on his way back from a visit to Rome, Ketteler died suddenly. He was buried in Mainz, mourned across confessional and political divides. One Essen newspaper praised him for “knowing no apprehension or fear. When he clearly grasped something as right, he spoke before both friend and foe.” The “farmer’ priest” passed away as the best known and most respected bishop in Germany.

If Christians choose to live as Christ did, thought Ketteler, the injustices inflicted upon the poor will be swept away.

In life, Ketteler’s influence was built on a rare ability to combine radical critique with pragmatic politics. In death, his legacy crystallizes almost exclusively around the latter. Although social Catholics retain Ketteler’s commitments to fair wages, trade union rights, and, in a much-diluted form, his enthusiasm for workers cooperatives, the spirituality they were founded upon – the critique of private property made in the 1848 sermons – is forgotten. 

The reversal was most complete at the height of Ketteler’s posthumous fame: Pope Leo XIII’s 1891 encyclical Rerum novarum, the “founding document” of Catholic social thought. Pope Leo, who praises Ketteler in the letter as “my great predecessor,” affirms many of the German bishop’s pioneering ideas, reaching out a hand to organized labor after decades of ecclesiastical mistrust. But where Ketteler founded his ideas on a critique of modern, absolutist interpretations of private property rights, Rerum novarum stressed, in language previously unknown to Catholic thought, “the inviolability of private property.”

The pope’s rapprochement with the sanctities of industrial capitalism was used, in the decades that followed, to attack the same secular trade unions and socialist groups that Ketteler had applauded. Those socialists didn’t leave the irony uncommented upon. In Vorwärts, the paper of the German Social Democrats – the successor to Lassalle’s workers’ association – an editorial remarks on the encyclical’s “tepidity” compared to “the radical program” of Bishop Ketteler.

It was a comment that could have been repeated many times in the years following the bishop’s death: Ketteler’s example was lauded, and his politics abandoned. Ludwig Windthorst, leader of the Catholic Center party Ketteler had helped found, rejected his forebear’s proposals for cooperatives, telling an audience of workers in 1879 that they could only improve their conditions by “hard work and prayer.” And in the decades that followed, Ketteler’s skepticism of state power passed into history as well. Where the bishop had bridled at Lassalle merely soliciting state funds for cooperatives, early twentieth-century Catholics would see a powerful “corporatist” state as the organizing principle of all economic life.

Forty years after Rerum novarum, the papal letter Quadragesimo anno only grudgingly concedes that Catholics might join “secular labor unions,” a striking contrast from Ketteler’s unambiguous endorsement of such groups seventy years before. The Center Party’s post-World War II progeny, the Christian Democratic Union, declares itself opposed to capitalism in the name of “Christian Socialism” in its 1947 manifesto; a pledge rapidly abandoned under the pressures of the Cold War. In 1948, Christian Democrat Economics Minister Ludwig Erhard abolished price controls in Germany and the “social market economy” was born. Its embrace of “genuine performance-based competition” stood in tension with Ketteler’s conviction that market forces, built on human desires for personal gain, could never ensure the welfare of all. 

The Vatican-sponsored Council for Inclusive Capitalism, founded by a compact of businessmen and bishops in 2019, takes roughly the opposite approach to Ketteler: property is not justified by fulfilling human needs, but fulfilling human needs by their posited benefits to property: inclusive capitalism, the group states, is “fundamentally about creating long-term value for all stakeholders.” Meanwhile, the injustice and inequality Ketteler saw as symptomatic of spiritual sickness persists. Half of the global population lives on under $6.85 a day. Roughly 1.6 billion people lack adequate housing, while 10 percent of the world go to bed hungry. How might Ketteler respond to the conditions we live in today?

He would likely tell us, as he told the faithful in his Advent sermons, to pay attention. We must look at the world through the eyes of those immiserated by it: “research the sources of poverty, share the sufferings and tears of the poor.” Ketteler teaches us that we must be constantly alert to the situation of the poor, and to seek to understand how it can be changed with the means available to us, just as the bishop did when he wrote to his socialist contemporaries. 

In the traditional heartlands of the church – and of capitalism – hope for a more just world is in even shorter supply than faith in God. The two may well depend, as Ketteler thought they did, on each other. No one would have expected the noble-born “farmers’ priest” and rising star to denounce private property, still less to open dialogue with secular socialists. Ketteler did not set out to be a radical; he only tried to be a Christian. In a society as unloving and exploitative as Ketteler’s – or our own – the truths of Christ’s life among us invite radical conclusions.

And the gap between the Social Bishop and the social teaching he helped create may finally be closing. In 2020, Pope Francis’ Fratelli tutti revised Rerum novarum’s declaration on the “inviolability of private property.” The pope stated unambiguously that property was a right secondary to the demands of justice, just as Ketteler declared from the pulpit more than 160 years before. The Catholic Church now, as it was then, might not seem like an obvious place to hear a radical critique of capitalism. But perhaps it can still surprise us.