Cardinal Avery Dulles: Jesuit priest and theologian Catholic theologian

Avery Dulles' appointment as cardinal in 2001 was typical of Pope John Paul II: it was a wildcard choice. Dulles did not toil in the Vatican bureaucracy, nor was he the head of a major archdiocese in a national capital. Indeed, he was one of only a handful of priests to be named cardinal in recent times. He was also a Jesuit: the Constitutions of the Society of Jesus enjoin its members to avoid striving for higher posts and to accept them only when insisted on by superiors.

So Dulles became the last of 44 candidates to line up in front of Pope John Paul. As he rose after receiving the blessing and embraced the pontiff, his red biretta fell off. It was, the new cardinal told his friends, a salutary humbling.

Even more unusual were his origins: his family, influential rather than vastly wealthy, had a long-established Presbyterian commitment to public service. His father, John Foster Dulles, had headed the US State Department (as the third family member to hold the post) and his uncle, Allen Dulles, had been a director of the CIA. His grandfather had been a Presbyterian minister and theologian.

Though professing to be an agnostic as he grew up in elite private schools in New York, Switzerland and New England, Dulles rocked his family when he converted to Catholicism in 1940, while a student at Harvard Law School. "The more I examined, the more I was impressed with the consistency and sublimity of Catholic doctrine," he later recalled.

Dulles's family was not impressed. The Catholic Church may have been the largest single religious body in the United States, but it was a church of working-class immigrants from Europe: Ireland, Poland, Italy, Lithuania and Germany. The family of descendants from Puritan migrants wondered how an intellectual young man could be attracted to finding truth in such a backward form of Christianity.

Dulles's intellectual conversion had turned into a praying faith beside the Charles River in Boston one winter's day, when he contemplated a tree that he determined was following "a rule, a law of which I as yet knew nothing". His short memoir of his conversion – mainly written while at sea during the Second World War – was published in 1946 as A Testimonial to Grace.

But the family was in for a further shock. In August 1946 – after graduation from Harvard in 1940, a year and a half at Harvard Law School, wartime service in the United States Navy in the Atlantic, Caribbean and Mediterranean (for which France awarded him a Croix de Guerre), and recovery from polio which he had contracted in Naples – Dulles joined the Jesuits.

Ten years later, in June 1956, Dulles was ordained priest by Cardinal Francis Spellman of New York at the then Jesuit-run Fordham University in the Bronx. His Secretary of State father, his mother, Spellman and he posed for the camera, smiling, on the church steps. By that time Dulles had already begun the study, teaching and writing that would be his legacy. From 1951 to 1960 he studied at the Jesuit seminary in Woodstock near Baltimore and at Munster in West Germany and gained a doctorate at the Gregorian University in Rome.

Dulles taught at the Woodstock seminary from 1960 until its closure in 1974, and then at the Catholic University of America in Washington DC. In 1988 he returned to Fordham, which was by then an independent foundation. His primary mission was as a teacher, giving lucid, well-crafted and intellectually challenging lectures which were informed by deep faith and wide reading but lightened by self-deprecating humour. Indeed, many of his more than 20 books and 700 articles began life as lectures.

Dulles tackled many of the issues facing a Catholic Church that was undergoing a profound social transformation. He addressed the changes brought about in theology, liturgy and practice in the wake of the Second Vatican Council (1962-65), seeking to explain them to intelligent listeners and readers and to link new thinking to its roots in Catholic tradition. In Models of the Church (1974), he looked at how the Church can be viewed, identifying five "models": as institution, mystical communion, sacrament, herald and servant. In a new edition of the book, in 1987, Dulles added a sixth category, seeing the Church as a "community of disciples".

From the perspective offered by his work in Christian Church history, Dulles was able to articulate where he felt change was needed. As he wrote in 1992, "commitment to the Church is a normal prerequisite for competently criticising the Church". Yet he did not advocate any very distinctive views or found his own school of theology. Billed by some Catholic commentators as a "moderate" and by others as a "conservative", he became adept at devising elegant reasoning for prevailing theological currents in the Vatican, something that brought him to the attention of successive popes.

When John Paul II asserted as the "deposit of faith" that women could not become priests, but chose not to declare that this was an infallible doctrine, Dulles leapt to defend the teaching. "The pope did not engage his infallible magisterium in the declaration," he declared. "Rather, by his ordinary and noninfallible teaching authority, he vouched for the infallibility of the teaching".

In 1994 he was able to admit cheerfully of John Paul II that "I don't think he knows who I am", but in 2001 he received the ultimate papal endorsement, the pope having acceded to Dulles's unusual request not to be made a bishop. During Pope Benedict XVI's visit to the United States in April 2008, the ailing Dulles was granted a personal audience, though by then he was unable to speak, owing to a recurrence of his polio.

In some ways his most personal study came in his short book Newman (2005), in which he looked at the life and teaching of the 19th-century English cleric and scholar John Henry Newman. Fittingly, it was during his research on this fellow-convert who became a cardinal that Dulles too was made a cardinal.

Felix Corley

Avery Robert Dulles, priest and theologian: born Auburn, New York 24 August 1918; entered Society of Jesus 1946; ordained priest 1956; lecturer, Woodstock College 1960-74; Professor of Systematic Theology, Catholic University of America 1974-88; Laurence J. McGinley Professor of Religion and Society, Fordham University 1988-2008; named a cardinal 2001; died New York 12 December 2008.