In Rome, Pope Francis urged bishops to be frank and not afraid to "speak freely" as a synod on the thorny subject of Catholic teachings on the family opened.
The pope has made himself the "guarantor" of the smooth running of the extraordinary meeting, which will tackle the delicate issues of unmarried couples, single mothers and the remarriage of divorced people.
The roughly 250 bishops taking part in the debates, which will go on until October 19, must "talk clearly" and welcome the "contributions of others with humility... to progress the Gospel of the family," Francis said.
"No one should say that we cannot say this or that because we are going to think like this... We must say everything, and be free to say everything that we feel," using the Greek word "parrhesia", meaning to speak candidly.
The synod opened in a relaxed atmosphere despite sharp exchanges in print and in interviews beforehand between cardinals on the controversial question of whether remarried divorced Catholics should be allowed to receive communion.
- Vast consultations -
The synod's secretary general, Cardinal Lorenzo Baldisseri, talked of the "long road" the pope had wanted the discussions to take, with a consistory meeting held in March, two synods (the second will be held next October) and vast consultations of the Church's dioceses.
The final document from this month's synod will be put to a vote and sent to all dioceses, possibly with a "questionnaire" to help clarify issues, the cardinal said.
The synod itself was put together from a questionnaire sent to dioceses last winter, with 84 percent getting back to Rome with their responses.
The results of the consultation after this synod will be used to put together the work document for next year's gathering.
The synod's relator general, the Hungarian cardinal Peter Erdo, stressed the importance of the Church's doctrine, notably on marriage: "Mercy does not annul the engagements born from the bond of marriage, they continue even when human love has weakened or ceased."
On homosexuality Erdo said there was a "large consensus" among bishops about not discriminating against gays, but "clarity" also "that one cannot expect that these relations can be put on an equal standing with the marriage of a man and a woman".
Cardinal Andre Vingt-Trois, the Archbishop of Paris and one of the synod's vice-presidents, said the synod was not "a parliamentary debate" but was about reaching a consensus. "We are here to build the common will of the Church."
He said the synod will give "universal directions" on issues, but then it was up to each local church to adapt them and "take concrete decisions".
He added that despite the pontiff's popularity, "the pope is not the bishop of my diocese and not the curate of the world".