Pope Benedict XVI entered the papacy with a reputation for being very conservative, and he has done little since becoming pope to call that into question. But in resigning his papacy, this very traditional pope has done one of the most modern things a pope could do - and in doing so has perhaps changed the way the Catholic Church thinks of its leader.

As head of the Vatican's Congregation for the Doctrine of the Faith (formerly the Holy Office of the Inquisition), Benedict XVI - then Cardinal Joseph Ratzinger - was charged with guarding the orthodoxy of Catholic teaching and occasionally with silencing those who deviated from it. As pope, Benedict returned to the use of more traditional papal vestments, presided over a gradual reversion to a more traditional liturgy, and spoke strongly against the modern voices of relativism and secularism. He strengthened and promoted church teaching supporting traditional marriage and in other areas. He did not seem like an innovator, nor did anyone really expect him to be.

Yet this most traditional man of the church has surprised us with a very modern innovation - the idea that the office of pope and the man who holds that office are separate and separable. Paul VI and John Paul II held the office to the end of their lives, through illness and debilitation, each leaving the church rudderless in the final years of their pontificates. Benedict has avoided that and given witness to spiritual freedom and generosity by laying down an office that he could have held onto. In his awareness of the demands of the modern papal office and his difficulty in meeting them, he has also shown great humility and simple good judgment.

But perhaps lost in our surprise at this decision is the fundamental insight at the heart of it: The papacy is an office that is exercised by a man for the good of the church. When that man can no longer exercise that office, for whatever reason, he should lay it aside and let someone else who can do so take it up. This is a very modern idea. U.S. presidents retain no legal power when they leave office. Honor and respect are accorded to those who have served in that office, but they become once again simple citizens upon leaving office.

The pope is a man who teaches with authority only because he is the Bishop of Rome. Once he no longer holds that office, he is simply one of many bishops in the Catholic Church. So striking and new is this idea that no one knows what a former pope should wear or how he should be addressed. By simply being the first former pope in more than 600 years, Benedict will be a living lesson in humility and the separation of power and person.

Some have suggested that Benedict's legacy to the church will be his well-received books on the life of Jesus or his theologically profound encyclicals. I believe that his lasting legacy may be in the way he left office with humility and grace. He showed us that the papacy is an office held by a man, a servant of the servants of God, who serves as long as he can and steps aside when he can serve no longer.

Joseph Curran is an associate professor of religious studies and chair of the Department of Religious Studies, at Misericordia University a four-year Catholic co-educational liberal arts university in Dallas, Pa.