Infallible? An Inquiry (Unfehlbar? Eine Anfrage) was published by Benziger Verlag in 1970, timed to coincide with the centenary of the First Vatican Council’s definition of papal infallibility (1870). It was the book that transformed Küng from a respected Catholic theologian into a controversial public figure — and ultimately led to the Vatican’s 1979 withdrawal of his license to teach as a Catholic theologian.
Küng’s argument is that papal infallibility — the doctrine that the Pope, speaking ex cathedra on matters of faith and morals, cannot err — is without adequate biblical or historical foundation, theologically problematic, and practically damaging to the church’s credibility. He examines the historical evidence (the councils and popes who contradicted each other), the theological arguments (which he finds circular), and the practical consequences (a church that cannot admit error cannot learn from its mistakes).
The alternative Küng proposes is “indefectibility” — the idea that the Church as a whole, guided by the Holy Spirit, will not permanently fall away from the truth, even though individual popes, councils, and doctrinal statements may err. This is a much weaker claim than infallibility, and it allows for the possibility that the Church can be wrong about specific questions and can change its mind.
Collecting Infallible? An Inquiry
First English edition (Doubleday, New York, 1971): Cloth binding, dust jacket.
Market values:
- First English edition in dust jacket: $15–$40
- First German edition (Benziger, 1970): $20–$50
- Paperback editions: $5–$10