Rivera, the Mexican cardinal, struck a similar humble tone, asking for prayers from all the faithful "so that the Holy Spirit helps us choose the best candidate to guide the church."
It should be noted that merely by speaking publicly, the cardinals may have jinxed their chances — which may have been their intention given that the papacy is a job few actively seek. But in today's media-driven world, where cardinals and even the pope tweet, staying silent isn't an option — at least until the cardinals enter the frescoed walls of the Sistine Chapel.
After that, what goes on in the Sistine Chapel stays in the Sistine Chapel. Violation of the code of secrecy in a conclave means excommunication.
The Rev. Thomas Reese, who wrote about the conclave process in his 1996 book "Inside the Vatican," said each cardinal looks for three things in a papal candidate.
"Someone who has the same values and vision of the church that he has. ... Someone with whom he has a positive relation. They all want someone as pope who is their friend and will listen to them. ... And someone who will go over well in their own country, or at least not embarrass them."
In an email, Reese said American cardinals, for example, want a pope who understands the church sex abuse crisis. A cardinal from a Muslim country, he added, wouldn't want a pope who has said provocative things about Islam.
Given those requirements, it's only natural that there be debate in the run-up to the conclave, and on the sidelines once it's under way.
"It's not like an American election with nominating speeches," said Christopher Bellitto, a church historian at Kean University in New Jersey. Once the conclave has started, "all they do is vote, so all the politicking takes place over dinner and espresso and cigarettes."
Bellitto said this conclave will be unique because cardinals won't feel the need to refrain from discussing their picks in advance of the gathering. In the past, such discussions were considered unseemly with a pope nearing death, as during Pope John Paul II's long, debilitating illness.
But with Benedict's announced resignation, there's little reason not to start the negotiations right away, he said.
"Now they've got two weeks' notice, more time for cardinals to start talking," he said. "Maybe they'll talk more openly among themselves."
Lest anyone forget, theologically speaking, the Holy Spirit has a role to play in the process. Picking a pope isn't just a human process, but a divine one.
Benedict addressed that point in a 1997 interview with Bavarian television, when he was still Cardinal Joseph Ratzinger and the Vatican's chief theologian.
The Holy Spirit, he said, doesn't actually choose the pope since "there are too many contrary instances of popes the Holy Spirit would obviously not have picked."
"I would say that the spirit does not exactly take control of the affair, but rather like a good educator, as it were, leaves us much space, much freedom, without entirely abandoning us."
In the remarks, which were reprinted in the book "Conclave" by veteran Vatican analyst John Allen Jr., the future pope continued: "Thus the spirit's role should be understood in a much more elastic sense, not that he dictates the candidate for whom one must vote. Probably the only assurance he offers is that the thing cannot be totally ruined."
Associated Press writers Geir Moulson in Berlin, Eduardo Castillo in Mexico City, Fabiola Sanchez in Caracas and Luis Henao in Santiago, Chile, contributed to this report.
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