The following article was in the NY Times and can be found in most newspapers (through the AP). The Vatican has reaffirmed the ban on women becoming priests to the point of excommunicating any woman who undergoes ordination and any clergy who ordain women. Part of the reason given is that Jesus only had male apostles. This conveniently ignores ancient traditions that calls Mary Magdalene the Apostle to the Apostles and in Orthodox tradition as "equal to the apostles" (see the comments by Shades of Gray and Black). Although Orthodox traditions, too, do not ordain women. This also ignores the prominent role women played in the early Christian movement, being leaders in the community, especially in association with and evidenced by Paul (figures such as Priscilla, Lydia, Euodia, Syntyche, Phoebe, who was a deacon, etc.), before their leadership roles were curtailed in later centuries.
The other reason that is often offered is that God is male and, therefore, can only be represented by men. There are many ways to discuss this in the tradition. Firstly, there is now evidence that in the pre-exilic period, the Israelites worshiped YHWH and the Queen of Heaven, or the goddess, Asherah, who was considered YHWH's consort. The opposition to and repression of this tradition was by those few men who controlled and tried to centralize the cult to YHWH to only Jerusalem (prominently the Deuteronomic School and its successors and the prophet Jeremiah)--this is now very clear. Secondly, the books that became the Bible (and that excised many of these earlier traditions or polemicized against them) were written by men and reflect a male-centric worldview. These men made God in their own image. Yet, evcen so, God as "father" is probably meant to be as literal as God as a "shepherd" or whatever. Thirdly, even the canonical texts use feminine imagery with God, such as God's "compassion" which is cognate with "womb"--it is literally God's "womb love" (see Jer. 49:15). For other feminine imagery applied to God, see Deut. 32:11, Ps. 17:8, 22:9-10, 36:7, 91:4, Hos. 13:8. Especially prominent here is the imagery of God as a mother hen who gathers her chicks under her wings. Interestingly enough, Jesus also uses this imagery to regard himself as a mother hen and the children of Jerusalem as the chicks (Luke 13:34-5). In the books of Sirach and the Wisdom of Solomon, especially the latter (which, one might emphasize, the Catholic Church takes as canonical, whereas Protestants do not), portray a feminine aspect of God; namely, God's Wisdom (Sophia). In Jewish traditions, moreover, the "presence" of God is the feminine Shekhinah.
Similarly, one argument is that Jesus was male and, therefore, only a male can handle the Eucharist and effect the transformation (transubstantiation) of wine and bread into the blood and flesh of Christ--although, it does not seem that based upon Jesus' interactions with women or even Paul's that they thought so (see first paragraph above). This argument seems like a stretch. One could just as easily argue that since Jesus had brown hair (or likely had brown or black hair) that no blond haired person should be allowed to perform the Eucharist--for how could a blond priest possibly represent a dark-haired Jesus? Or perhaps that since Jesus was Jewish, only a Jew can effect transubstantiation (that will definitely make things difficult indeed). I personally do not know any ancient traditions that actually exclude women in this way for this reason. This explicit reasoning seems to be a much more recent innovation, a post-facto rationalization of previous practice mixed with suppression of the earlier traditions mentioned above (both canonical and non-canonical).
Vatican Asserts Rule That Bars Female Priests
ROME — The Vatican on Friday reaffirmed a ban on ordaining women as priests, warning that the consequences of any such ordination would be the automatic excommunication of anyone involved.
The decree was a reaction to specific episodes of “so-called ordinations in various parts of the world,” according to Msgr. Angelo Amato, the secretary of the Congregation for the Doctrine of the Faith, which issued the decree. In recent years, dozens of women have been ordained by individuals acting outside of the church’s authority.
The document was also drafted to give bishops uniform guidelines on an increasingly contentious matter, as a growing number of Catholics contest the church’s position that only men can be ordained as priests.
In an interview for Vatican Radio, Monsignor Amato reiterated that the church did “not feel authorized to change the will of its founder, Jesus Christ.” The Vatican, he added, felt “in good company” because the Orthodox and ancient Eastern churches have also preserved what he said was a 2,000-year-old tradition.
The decree went into effect on Thursday, after it was published in the Vatican newspaper, L’Osservatore Romano.
Last March, the archbishop of St. Louis, Raymond L. Burke, excommunicated two women in his diocese and another living in Germany after they were ordained as priests as part of the Roman Catholic Womenpriests organization.
In the past six years, the organization says it has ordained more than 50 women and some men as priests and deacons in North America and Europe. In 2002, the Vatican excommunicated the first seven women shortly after the organization designated them priests.
On Friday, Bridget Mary Meehan, a spokeswoman for the group, said the excommunication, which extends to both the women and the bishops ordaining them, was a positive sign “that the Vatican is taking us seriously.”
Excommunicated Catholics cannot participate in the sacraments or public ceremonies or hold any ecclesiastical position.