Hans Küng as a Modernist Theologian at the Second Vatican Council

This article explores the role of Hans Küng (1928–2021) as a leading figure among reform- minded theologians at the Second Vatican Council (1962–1965). As the youngest peritus — a theological expert invited to advise the bishops — Küng played a significant role in shaping key conciliar documents, particularly those concerning ecclesiology and ecumenism. The article traces the development of his theological position, from active engagement in Council debates to his later radical critique of papal infallibility, which ultimately led to the withdrawal of his licence to teach Catholic theology. It places particular emphasis on Küng’s contested legacy: while he inspired theological renewal after the Council, his increasingly radical stance provoked lasting conflict with the Church hierarchy. The article argues that Küng’s trajectory exemplifies the Council’s central tension — the fragile balance between reformist ambition and institutional constraint.