The most influential
Catholic theologian of the
20th century. Born in Freiburg, Germany in 1904, Rahner followed his brother
Hugo into the
Jesuit order and was ordained as a priest in 1932. He studied at the University of
Freiburg under
Martin Heidegger, the leading German philosopher of the 20th century, who influenced much of his later work. He lived through the
Nazi regime without getting into trouble but avoided any contact or association with the Nazi party. His views on individual freedom were undoubtedly influenced by his experience of Nazi rule.
After World War II he began to write voluminously on almost every subject of theological inquiry. He worked to frame Catholic theology in the context of existential philosophy, which the Vatican viewed as an inherently anti-Christian philosophy. Rahner made a distinction between the language and the content of a particular dogma, and worked to communicate the "essential truth" of a doctrine to find in it a message that was comprehensible to the people of his time. His attempt to translate theology into the philosophy of his own century was not all that different from the work of Thomas Aquinas, who framed Christian theology within the philosophy of Aristotle in the 13th century.
However, instead of a "summa" he wrote countless articles and short books, many of which were collected into a 24-volume series called (in English) Theological Investigations. Rahner's work is notoriously difficult to read--his brother, a noted theologian in his own right, once wrote that his life's work was to "translate Karl's writing into German." Rahner worked at the edges of Catholic theology but always remained connected to the center, and so he continually zig-zags through conceptual minefields as he balances tradition and innovation, moving diagonally through his argument until at the end he reaches an often unexpected conclusion. His ability to draw radically new ideas from a careful examination of the meaning of indulgences or the teaching of the conservative Pope Pius XII brought him under suspicion, and in 1961 the theological officials of the Papal Curia assigned a censor whose only job was to read his works. (When Alfredo Cardinal Ottaviani, the chief theological policeman of the Vatican, told him that personal attention he received was a privilege, he replied, "Your Eminence, I renounce privilege.")
When the Second Vatican Council was called in 1962, Rahner became the chief theological expert for the German-speaking bishops, even though he was still being investigated by the Curia's doctrinal policemen. In addition to contributing directly, he heavily influenced Josef Cardinal Frings, who sat on the Council sub-committee that drafted its most important documents. In the end, Vatican II officially approved a doctrinal statement on the nature of the Church that was substantially crafted by Rahner. In 1961 Rahner was under a cloud; in 1964 his work had been officially endorsed by the highest authority in the Catholic Church.
Rahner continued to work after the Council. He intervened on behalf of the noted, younger theologian Eduard Schillebeeckx when Curial officials attempted to silence him in 1968, and became a lead editor of the influential journal Consilium. He continued to write and speak actively until his death in 1984.