Four years ago I did a column marking the feast days of two of the Church's most important saints: Charles Borromeo (1538-84; feast day, November 4) and Leo the Great (pope from 440 to 461; feast day, November 10).

Leo was still only a deacon when elected to succeed Pope Sixtus III. Indeed, he was not even present at the conclave that chose him, having been away from Rome on a diplomatic mission.

As pope, Leo became a strong advocate of papal authority, but he himself was not interested in power for power's sake. He used his authority to root out abuses in the Church, to resolve disputes, to insure unity in pastoral practices, and to help clarify the Church's teaching about the divinity and humanity of Jesus Christ.

When another bishop, Hilary of Arles, presumed to exercise authority over neighboring French dioceses, Leo ordered Hilary to confine his pastoral activities to his own diocese.

Bishops, Leo insisted, are to be elected by their own clergy and leading laity, and their elections are to be ratified by the rest of the diocesan community, without interference even from Rome.

Leo's electoral principle, "He who is to preside over all must be elected by all," has been quoted throughout the subsequent history of the Church and to this very day, but unfortunately the principle has not been observed for centuries.

Indeed, the writings of Pope Leo the Great and also those of another great pope, Gregory I (590-604), testify that it was entirely normal for the Church in the West --- that is, in Italy (including Rome), Gaul, northern Europe and North Africa --- to select its pastoral leaders with and through the consent of the clergy and laity, as well as the bishops of neighboring dioceses.

However, if the bishops and clergy were to prefer a candidate whom the laity disapproved of, that candidacy would not likely survive. That is how decisive the voice of the lay faithful was in the early Church.

Only later did temporal rulers and the pope himself become directly involved in the selection of bishops. But not even the pope had a direct hand in episcopal appointments outside of Italy until the end of the First Christian Millennium.

By the 10th century, however, the role of the local clergy and laity in the election of their bishops was practically non-existent, having been supplanted by political leaders and powerful families.

With the reform movement of the 11th century, led by Pope Gregory VII (1073-85), the extra-ecclesiastical hold on church offices began to weaken, but the reforms also produced an unintended consequence, namely, the centralization of authority in the papacy. This development would shape the history of the papacy throughout the Second Christian Millennium and even into our own time.

The reform movement did try over the next several decades to restore the ancient practice where the clergy and laity as well as neighboring bishops had some decisive input into the selection of bishops, but the effort eventually failed and popes, kings and local princes filled the void.

The laity were limited to consenting "humbly" to whatever choice had been made for them, just as is the case today.

It was Pope Pius VII's concordat with Napoleon in 1801 that had the effect of vesting in the pope alone the power to appoint bishops anywhere in the Roman Catholic Church. And that system has remained in place ever since.

The fact that this method of appointing and promoting bishops has absolutely nothing to do with the will of Christ or with the authentic tradition of the Church seems to escape many Catholics, and not a few bishops who themselves have benefited from the break with the ancient practices.

Finally, it was also Leo the Great who made a point of referring to himself as the Vicar of Peter, always careful to add that "the blessed apostle Peter does not cease from presiding over his see."

The popes of the fifth and sixth centuries regarded themselves as "holding the place" of Peter, and even into the 11th and 12th centuries the title "Vicar of Peter" remained in use to designate the Bishop of Rome, alongside "Vicar of Peter and Paul" and "Vicar of the Apostolic See."

"Vicar of Christ" also has a long history, but not as a papal title. It was applied to every priest at least from the third century and to all bishops in the Middle Ages. Vatican II also referred to bishops as "the vicars and ambassadors of Christ" (Dogmatic Constitution on the Church, n. 27).

Leo the Great's legacy remains a challenge for the Church today.

Fr. Richard McBrien is the Crowley-O'Brien Professor of Theology at the University of Notre Dame.