A few weeks ago, the National Catholic Reporter (NCR) editorialized in favor of the ordination of women in the Roman Catholic Church. Today, Gary Macy at NCR argues that women were once ordained, but were squeezed out in the 11th-13th centuries.
According to Macy, prior to the 12th centuries, Roman Catholicism had a different view of ordination than they do today. Quoting Yves Congar, "the words ordinare, ordinari, ordinatio signified the fact of being designated and consecrated to take up a certain place, or better a certain function, ordo, in the community and at its service." (Today, this would be a rather Lutheran view.)
Under the older definition of order...women played several liturgical and administrative roles now reserved to deacons, priests and bishops. Evidence from the fourth through the 11th centuries indicates that a few women led liturgies with the approval of at least some bishops.
The standard line is that all Jesus' disciples were men, and therefore, all his priests should be men. Pope John Paul II actually said this with a straight face, ignoring that Jesus' disciples were all middle-eastern Jews as well. By his logic, all priests should be Jews!