<P> There has never been any doubt, however, that it is an ecclesiastical discipline, as the Council Fathers explicitly recognised when they stated that "it is not demanded by the very nature of the priesthood ." Pope John Paul II took up this theme when he said at a public audience on 17 July 1993 that celibacy "does not belong to the essence of priesthood ." He went on to speak of its aptness for, and its congruence with, the requirements of sacred orders, asserting that the discipline "enters into the logic of (priestly) consecration ." </P> <P> Yet some commentators have argued for the possibility that married men of proven seriousness and maturity (viri probati, taking up a phrase which appears in the first - century First Epistle of Clement in a different context) might be ordained to a localized and modified form of the priesthood . The topic of viri probati was raised by some participants in discussions at Ordinary General Assembly XI of the Synod of Bishops held at the Vatican in October 2005 on the theme of the Eucharist, but it was rejected as a solution for the insufficiency of priests . </P> <P> Pope Francis shared his views on celibacy, and the possibility of church discussion on the topic, when he was the Archbishop of Buenos Aires, recorded in the book On Heaven and Earth, a record of conversations conducted with a Buenos Aires rabbi . He commented that celibacy "is a matter of discipline, not of faith . It can change" but added: "For the moment, I am in favor of maintaining celibacy, with all its pros and cons, because we have ten centuries of good experiences rather than failures...Tradition has weight and validity ." He said that now the rule must be strictly adhered to, and any priest who cannot obey it "has to leave the ministry ." National Catholic Reporter Vatican analyst, Jesuit Thomas J. Reese, called Bergoglio's use of "conditional language" regarding the rule of celibacy "remarkable ." He said that phrases like "for the moment" and "for now" are "not the kind of qualifications one normally hears when bishops and cardinals discuss celibacy ." </P> <P> In a conversation with Bishop Erwin Krautler about mandatory celibacy on 4 April 2014, the Pope also spoke about a possible mechanism for a change starting with national bishop conferences . These conferences would </P>

When was celibacy established in the catholic church