With Pope John Paul II's (search) recent health crises, talk that he might consider resigning has intensified. Yet most popes have rejected that idea, even though the option remains available to them under church law.

The Rev. Thomas Reese, editor of the Jesuit magazine America and a Vatican expert, said popes worry that stepping down would set a dangerous precedent that could be misused by factions in the church to pressure a future pontiff to leave. No pope has resigned for centuries.

Resigning also clashes with the notion of a pope's special role in guiding the church, said the Rev. Joseph Fessio, editor of Ignatius Press, a top U.S. Catholic publisher. "He is a spiritual leader and a father in the faith and fathers don't resign," Fessio said.

John Paul has consistently brushed aside any speculation, often declaring he would carry out his mission until the end. His steadfastness is viewed by many as a powerful example of Roman Catholic teaching about the value of life, even in the face of intense suffering.

"My sense is that John Paul II sees his own life in a way as a symbol and that being the leader of the church in both health and in sickness all the way down to the end is a witness to the Christian message he is trying to preach," said Daniel Thompson, a theology professor at Fordham University in New York.

No more than 10 popes are believed to have stepped down, though the historical evidence is not clear, Reese said.

The most famous is Pope Celestine V (search), who assumed the papacy in 1294 at age 85 and resigned five months later, saying he was not up to the task. He was later put under guard for fear he would become the rallying point for a schism.

Talk about John Paul eventually stepping down has been in the air for almost a decade, as the pope has visibly weakened from Parkinson's disease and hip and knee ailments. His speech has been slurred for some years and because of difficulties to even stand, he now uses a wheeled throne pushed by aides. His health problems have not hindered the day-to-day operation of the Vatican, which is overseen by the many officials working there, although only the pope can set major church policy, such as appointing bishops.

Cardinal Angelo Sodano (search), the Holy See's No. 2 official, inflamed public debate on the issue during John Paul's previous hospitalization earlier this month when he responded to a reporter asking whether the pope would ever consider stepping down.

While the cardinal expressed hope for the pope to continue, he also said, "Let's leave that hypothesis up to the pope's conscience."

"We must have great faith in the pope. He knows what to do," Sodano said on Feb. 7.

Since then, several other cardinals have made similar comments, while others have expressed anger about the discussion. "It is bad taste to talk about it," said Cardinal Giovanni Battista Re, head of the Congregation of Bishops.

If John Paul did decide to step down, the wording of canon law on resignation would pose potential problems, Reese said. The resignation must be "freely made and properly manifested," according to church law, but it is not clear what would be done if the pope becomes incapacitated.

The Vatican has declined to comment officially on whether John Paul has left written instructions in the event that he lapsed into a coma or another incapacitated state. Other recent popes are said to have done so.