"We are not free to invent the priesthood according to our own customs, according to our own expectations," says Fr. Wojciech Giertych.
A Vatican official on Monday voiced support for giving unmarried couples some kind of legal protection even as he reaffirmed the Catholic church's opposition to same-sex marriage.
Pope Benedict XVI asked nuns, brothers and priests not to listen to the "prophets of doom" who say consecrated life has no future or that it has no meaning in today's world.
"Do not join the prophets of doom who proclaim the end or the lack of meaning of consecrated life in today's church; rather clothe yourselves with Jesus Christ and put on the armor of light ... remaining awake and vigilant," Pope Benedict told consecrated virgins and men and women who belong to religious orders.
Even if youth culture is often marked by individualism, superficiality and hedonism, a cardinal said Thursday that its diversity "contains surprising seeds of fruitfulness."
Two months after receiving their red hats, the six newest members of the College of Cardinals have received their assignments as members of Vatican congregations, councils and offices -- one of the clearest ways they help Pope Benedict XVI govern the universal church.
While keeping their main jobs, the new assignments allow the cardinals to bring their experience and perspective to bear on the discussions and decisions of the central church offices that assist the pope.
Speaking to the members of the tribunal of the Roman Rota, Benedict said "lack of faith" on the part of the spouses can affect the validity of a marriage.
A lack of faith in God can damage marriage, even to the point of affecting its validity, Pope Benedict XVI said.
"Faith in God, sustained by divine grace, is therefore a very important element for living in mutual dedication and conjugal fidelity," he said.
The pope said he was not suggesting there was a simple, automatic link "between the lack of faith and the invalidity of marriage."
Diplomatic relations between the Vatican and Vietnam were strengthened in January, officials said, when Pope Benedict XVI met Nguyen Phu Trong, marking the first time a pope had met with the general secretary of the nation's Communist Party.
Trong, who has been general secretary of the party since 2011, was accompanied by an 11-person delegation of other high-level party and government officials. The Vatican was one of a number of stops the delegation had planned in Europe.
The Vatican on Thursday defended the pope's choice to open a Twitter account, even if it exposes him to insults and online abuse.
"Twitter is a secular reality ... but we prefer to be present rather than stay away from something just to avoid a risk," said Archbishop Claudio Maria Celli, head of the Vatican's department for social communications, during the launch of the annual papal message for World Communications Day.
Pope Benedict XVI opened his Twitter handle @Pontifex on Dec. 3. It has since gathered more than 2.5 million followers in nine languages, including Latin.
The Catholic church has never encouraged anyone to use ivory for religious devotional objects and, in fact, teaches that animals must be treated with respect, the Vatican spokesman said in a letter to "friends of the elephants."
Jesuit Fr. Federico Lombardi, responding to questions posed in an online National Geographic editorial, said, "thinking that there is an important ivory trafficking center to uproot here (in the Vatican) in order to save African elephants makes no sense."