All Thinkers

Hans Küng

Hans Küng was a Swiss Catholic priest and theologian. A theologian is a scholar who studies the meaning and history of religion. He was born in 1928 in Sursee, a small town in central Switzerland. He died in 2021 in Tübingen, Germany, at the age of 93. Küng studied for the priesthood in Rome and was ordained a Catholic priest in 1954. From 1960 he was a professor at the University of Tübingen in Germany, where he taught for the rest of his career. In 1962 the Pope chose him as one of the youngest expert advisers at the Second Vatican Council. This was a great meeting of Catholic bishops that aimed to bring the Church into the modern world. Küng was one of the most famous and controversial Catholic thinkers of the twentieth century. He challenged the official teaching that the Pope could not be wrong on matters of faith and morals. He also criticised compulsory celibacy for priests and the ban on women priests. In 1979 the Vatican withdrew his licence to teach as a Catholic theologian. He kept his post at Tübingen and remained a Catholic priest. In his later years he led a global project on shared ethics across religions.

Origin
Switzerland
Lifespan
1928-2021
Era
20th-21st century / contemporary
Subjects
Catholic Theology Ecumenism Interfaith Dialogue Global Ethics Religious Reform
Skills
Critical Thinking Ethical Thinking Research Skills Cultural Heritage And Identity Creative Expression
Why They Matter

Küng matters as one of the most influential Catholic theologians of his time. He was a leading voice for change inside his own Church, even when this brought him into deep conflict with Rome.

His most famous challenge was to the doctrine of papal infallibility. This is the official Catholic teaching that the Pope, in certain formal statements about faith and morals, cannot be wrong. In his 1971 book 'Infallible? An Inquiry', Küng asked whether this teaching was really justified by the Bible and Church history. The book caused an uproar. In 1979 the Vatican withdrew his licence to teach as a Catholic theologian.

Küng also pushed for many other reforms. He argued for married priests, for women priests, and for an end to the ban on contraception. The Catholic Church has not accepted these changes, but the questions he raised remain alive within it.

Küng matters too for his later work. In the 1990s he launched the 'Global Ethic' project. This was an attempt to find shared moral values across the world's religions. It produced a famous declaration signed at the 1993 Parliament of the World's Religions.

Key Ideas
1
Who Was Hans Küng?
2
The Second Vatican Council
3
What Is Papal Infallibility?
Key Quotations
"Küng challenged the Catholic teaching that the Pope cannot be wrong on matters of faith and morals."
— Description of the central argument of Hans Küng's book 'Infallible? An Inquiry', 1971
This describes Küng's most famous challenge rather than quoting his book. The official Catholic teaching is that the Pope, in certain formal statements about faith and morals, cannot be wrong. Küng asked whether this teaching was really supported by the Bible and Church history. For students, the value is in seeing how large a question this was. Küng was not arguing about a small detail. He was asking whether his Church's central rule about who decides truth was correct, and he did this as a serving Catholic priest.
"Küng stayed a Catholic priest his whole life, even when the Vatican withdrew his licence to teach as a Catholic theologian."
— Summary of Hans Küng's lifelong relationship with the Catholic Church
This summarises the shape of Küng's whole career. He criticised the Catholic Church from within, but he never left it. He remained a priest until his death in 2021. Even after the 1979 ruling, he kept saying Mass and serving as a Catholic. For students, this is a key point. Küng's example shows that you can deeply love an institution and deeply disagree with parts of it at the same time. Critic and loyal member are not always opposites. They were not, in his case.
Using This Thinker in the Classroom
Critical Thinking When teaching students that loyalty and criticism can go together
How to introduce
Tell students that Hans Küng spent his whole life as a Catholic priest, while also publicly disagreeing with his Church on major questions. Ask students whether you can love something and still criticise it. This teaches critical thinking. Students learn that loyalty does not always mean silent agreement. A person can stay inside a group or institution and still push hard for it to change. Küng is a clear modern example, and his life shows what this costs and what it can achieve.
Cultural Heritage and Identity When teaching students about the Second Vatican Council
How to introduce
Tell students that in the 1960s, hundreds of Catholic bishops met in Rome to bring the Catholic Church into the modern world. Küng was one of the youngest expert advisers. The Council allowed Mass in everyday languages and opened the Church in many ways. This connects to cultural heritage and identity. A vast religious tradition can be carefully renewed, without abandoning what makes it itself. Küng's career began in this moment of careful renewal.
Research Skills When teaching students to research the history of an idea
How to introduce
Tell students that Küng did not simply say papal infallibility was wrong. He researched its history, asking where the idea had come from and whether it was really supported by the Bible and the early Church. Ask students to take an idea they accept and try to find when and where it started. This teaches a real research skill. Many ideas that feel timeless have actually grown up at a particular time, for particular reasons. Tracing them back is part of honest study.
Further Reading

For a first introduction, Küng's book 'On Being a Christian' (1974) is long but written for general readers and shows his thinking at full strength. Shorter introductions and reliable encyclopedia articles give a clear overview of his life. Many interviews with him are available online, in which he explains his ideas plainly in his own voice.

Key Ideas
1
Loyal Critic, Not an Outsider
2
The 1979 Vatican Decision
3
The Global Ethic
Key Quotations
"Küng asked whether the doctrine of papal infallibility was truly supported by the Bible and by the early Church."
— Description of the central question of Hans Küng's 'Infallible? An Inquiry', 1971
This describes the actual question Küng raised rather than quoting his book. He did not just say infallibility was wrong. He asked, with careful historical work, where the idea had really come from. He concluded that it had grown up later, partly to defend the Pope's power, and was not clearly there in early Christianity. For students, this shows how serious religious questioning works. Küng was not protesting. He was researching: tracing an idea back through history and asking whether it stood up.
"Küng's Global Ethic looked at the world's religions and asked what shared moral values they hold in common."
— Description of Hans Küng's 'Global Ethic' project, central to his work from the 1990s
This describes Küng's later constructive project rather than quoting him. After his disputes with the Vatican, he turned outward. He looked across Christianity, Islam, Judaism, Buddhism, Hinduism, and other traditions, asking what core values they shared. He argued they all teach, in some form, not to kill, not to steal, not to lie, and not to exploit others. For students, the value is in seeing the move. Küng moved from arguing inside one religion to building bridges across many. Both stages were part of one life of religious thinking.
Using This Thinker in the Classroom
Ethical Thinking When teaching students about challenging authority
How to introduce
Tell students that Küng publicly challenged the central authority of his own Church and paid a real cost. In 1979 the Vatican withdrew his licence to teach as a Catholic theologian. Ask students when, if ever, it is right to challenge authority openly, and what the costs can be. This opens an honest ethical discussion. Students learn that real challenge is not free and not safe, and that respect for an institution and willingness to challenge it are not always opposites.
Cultural Heritage and Identity When teaching students about shared values across religions
How to introduce
Introduce Küng's Global Ethic project. He argued that the world's major religions, despite their differences, share core values such as not killing, not stealing, not lying, and not exploiting others. Ask students to think of values they believe almost all decent people share, across cultures. This connects to heritage and identity. Students learn that different traditions are not only different. They also share common ground, and finding it is a serious task worth doing.
Further Reading

For deeper reading, 'Infallible? An Inquiry' (1971) is the book that triggered his conflict with the Vatican and remains the clearest statement of his main challenge. His memoirs, especially 'My Struggle for Freedom' and 'Disputed Truth', tell the story of his career from inside. 'A Global Ethic for Global Politics and Economics' (1998) shows his later work across religions.

Key Ideas
1
His Famous Argument with Ratzinger
2
What Küng Pushed For That the Church Has Not Accepted
3
Late-Life Rapprochement
Key Quotations
"Küng described the 1979 Vatican ruling against him as his own personal experience of the Inquisition."
— Attributed to Hans Küng in his memoir 'Disputed Truth', describing the 1979 withdrawal of his licence to teach Catholic theology
This paraphrases something Küng wrote about himself, using a famous and powerful word. The Inquisition was the Catholic Church's historical court for hunting and judging dissenters, including with torture. By using the word, Küng was making a sharp comparison. He felt judged by his own Church without a fair hearing. For advanced students, the comparison is loaded but revealing. It shows how an old Catholic still felt the weight of the institution he loved, and how serious he believed the 1979 ruling was.
"In his last years, Küng said an exchange of letters with Pope Francis left him feeling almost informally restored to the Church."
— Description of Hans Küng's late-life relationship with Pope Francis, reported in interviews around 2019
This describes the soft, late-life ending of Küng's long argument with Rome rather than quoting a formal document. Pope Francis was more open to dissent than his predecessors. Küng exchanged letters with him and said in interviews that he felt 'quasi-informally' restored to his place. The official 1979 ruling was never formally lifted. For advanced students, the description matters. It shows that even long, painful disagreements between a person and an institution can shift, late in life, into something less harsh. This can happen without anything being fully resolved.
Using This Thinker in the Classroom
Critical Thinking When teaching students that institutions and dissenters need each other
How to introduce
Tell students the story of Küng and Joseph Ratzinger, later Pope Benedict XVI. They started as colleagues at Tübingen and ended on opposite sides of how the Church should be led. Ask students why a strong institution might need both careful leaders and serious internal critics. This teaches advanced critical thinking. Students learn that a healthy institution is not one without disagreement. The relationship between leaders and critics, while painful, can be part of how a tradition stays alive.
Ethical Thinking When teaching students that long arguments can soften without being resolved
How to introduce
Tell students that after Pope Francis was elected in 2013, Küng exchanged letters with him and said he felt 'almost informally' restored to the Church. The official 1979 ruling was never lifted. Ask students whether closure always means a full official decision. This opens a quiet ethical lesson. Students learn that real life is often less neat than formal records. Long disputes can soften into peace without anyone declaring victory. That is sometimes the most honest possible ending.
Common Misconceptions
Common misconception

Hans Küng left the Catholic Church.

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What to teach instead

He did not. Küng remained a Catholic priest from his ordination in 1954 until his death in 2021. Even after the Vatican withdrew his licence to teach as a Catholic theologian in 1979, he kept his priesthood, said Mass, and identified as a Catholic. His criticism came from inside the Church, not from outside it. Treating him as an ex-Catholic misreads his whole life's choice. He believed loyalty to the Church included the duty to criticise it honestly when he thought it was wrong.

Common misconception

The Vatican silenced Küng in 1979.

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What to teach instead

This is too strong. In 1979 the Vatican withdrew his missio canonica, the official licence to teach as a Catholic theologian. This meant he could no longer represent the Catholic Church as its theologian. But the Vatican did not remove his priesthood. It did not stop him writing or teaching at his secular university post in Tübingen. He kept publishing widely read books and giving public talks. The 1979 ruling was a serious blow to his standing, but it did not silence him. He spoke for the rest of his life.

Common misconception

Papal infallibility means Catholics believe the Pope is never wrong about anything.

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What to teach instead

This is not what the Catholic teaching says. The doctrine of papal infallibility was formally declared in 1870. It applies only to certain formal statements about faith and morals, made under specific conditions, intended to bind all Catholics. It does not say the Pope is always right in his daily life, his political views, or his ordinary teaching. This is a narrow and technical doctrine. Küng questioned even this narrow form. Treating infallibility as if it meant 'the Pope is never wrong' misrepresents both the Catholic teaching and what Küng was actually challenging.

Common misconception

Küng's Global Ethic argued that all religions are really the same.

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What to teach instead

This is not what he claimed. The Global Ethic project did not say that all religions are the same. It said something different. The world's major religions, despite their real and deep differences in belief and practice, share certain core moral values. These are rules against killing, stealing, lying, and exploiting others. Küng was clear that the religions remain different. He simply argued there is enough shared ethical ground to support a basic set of common moral standards for a shared world. The differences and the common ground both matter.

Intellectual Connections
Develops
Huldrych Zwingli
Zwingli, the Swiss reformer of the sixteenth century, broke from Rome and led one branch of the Protestant Reformation. Küng, also a Swiss religious thinker, stayed inside the Catholic Church but challenged its claims of central authority. Both, from Switzerland, asked hard questions of Rome. Reading them together gives students two very different responses to the same kind of question, across five centuries: one who left the Catholic Church to reform, and one who stayed inside it to push for change.
In Dialogue With
Thomas Aquinas
Aquinas built the great medieval system of Catholic theology, which shaped what the Catholic Church taught for centuries. Küng, twentieth-century theologian, worked within that tradition but also pushed against parts of it. He wanted Catholic teaching to engage seriously with modern thought, just as Aquinas in his time had engaged with the new philosophy of Aristotle. Reading them together shows how a living religious tradition both rests on great past thinkers and is reshaped by later ones.
Complements
Martin Luther
Luther, in the sixteenth century, broke from the Catholic Church partly over the question of who has authority to decide religious truth. Küng, four hundred years later, raised related questions about papal authority, but from inside the Catholic Church. They reached different answers about whether to stay or leave. Reading them together connects two great challenges to Rome, separated by centuries but linked by deep similar questions about who, in Christianity, has the final word.
Complements
Rumi
Rumi, the great Sufi Muslim poet, taught that the love of God runs across the world's religions, beyond their outward differences. Küng's Global Ethic project, centuries later, made a related argument in modern theological language. Both pointed beyond the lines that divide religions to a shared moral and spiritual core. Reading them together shows that the search for what unites religious traditions is not new. It has been a serious task for thoughtful believers for many centuries.
Complements
Khadija bint Khuwaylid
Khadija was a major early figure of Islam, central to its founding. Including her in a connection helps students see Küng's interest in serious dialogue across religions. Küng believed Christians should learn the actual history and texts of Islam, Judaism, and other faiths, rather than relying on stereotypes. Reading about figures like Khadija from inside Islam fits his approach. Real interfaith understanding, for Küng, started with serious knowledge of the other tradition, not with vague good will.
Complements
Teresa of Ávila
Teresa of Ávila was a sixteenth-century Spanish Catholic reformer of religious life. She worked from inside the Catholic Church to renew it, with deep faith and a sharp practical mind. Küng worked centuries later, also from inside the Catholic Church, but with academic theology rather than mystical experience. Both pushed for reform while staying loyal to the tradition. Reading them together shows two very different shapes of the same long Catholic story: faithful Catholics who pressed for change.
Further Reading

For research-level engagement, students should read Küng's major theological works such as 'The Church' (1967) and 'Does God Exist?' (1978). Critical responses from Catholic theologians who disagree with him, including Joseph Ratzinger, are essential for balance. The wider scholarly literature on the Second Vatican Council and on the modern Catholic Church places Küng's career inside its real context, including both his influence and its limits.