This is a talk Sr. Teresa Forcades i Vila gave about the Marian dogmas under the title "The Future of the Christian Experience". It is available on her Web site in its original Catalan and in a computer-assisted Spanish translation. Since I'm putting it on the blog, I have divided the text into four parts.
1. Introduction and Mary, Mother of God
2. Virgin Mary
3. Immaculate Mary
4. The Assumption of Mary, Conclusion and footnotes
2. Virgin Mary, Lateran Synod, 7th cent. (649)
What sense would it make to think that Mary conceived Jesus through a sexual relationship with Joseph or some other man and that later or simultaneously, God somehow made the one who had been or was being conceived the “Son of God” and “True God”? The problem with such an explanation would not be that it would be incredible – since the explanation that Mary conceived through the work of the Holy Spirit is equally incredible – but that its existential consequence -- that which this way of conceiving the Incarnation would be affirming about the possibility for our relationship with God and about the task of giving birth to it in the world (our Christification) -- would in fact link the possibility of fulfilling myself as a human being to the possibility of having a couple relationship. But no. Our personal fulfillment, our Christification, the fullness of our human potential, does not depend on whether or not we have a mate or on whether or not we have a sexual relationship; it only depends on our capacity to love God and that capacity to love God can be recognized in the love for others, above all for those who count for nothing (preferential option for the poor). If Mary had not been able to conceive Jesus without Joseph or another man, our Christification (the possibility of conceiving Christ within ourselves and giving birth to Him in the world) would not only remain linked to a couple relationship, but in particular to a heterosexual couple relationship (the only one capable of begetting biological children).
On the other hand, the dogma of Mary’s virginity puts our personal fulfillment in its proper sphere: in the intimacy of our relationship with God (which is shown in love of others). This intimacy with God can be experienced as much if one has a partner as if one doesn’t. Therefore the Christian couple is not a sacrament of God’s love to the extent that it is closed in upon itself, but rather in the heart of the community of faith.
The subject of personal fulfillment without a partner has historically been a particularly difficult point for women, as much due to external pressure as to inward belief. Society has tended to define us in terms of maternity and we women have tended to associate happiness with having achieved a life of coupledom. On other occasions I have taken a position on what I think is the origin of this problem.  Here I will limit myself to noting that to the extent that it is true that we women generally tend to fear solitude more than dependency and the men the reverse, the issue of virginity seen as an unyielding and incommunicable inner space from which it is possible to love freely, can be particularly important to us women.
My personal unyieldingness is the space that I cannot surrender even to God Himself; it is the condition of possibility for co-creation, the nucleus of my “alterity” with respect to God and with respect to any other creature, my unalienable dignity, my freedom. It is not a space one needs to protect or preserve. One only has to acknowledge it. The more centered a person is in this space, the more she is able to give of herself and love without dependence or limitation just as God loves us.
The important point of Mary’s virginity for the Christianity of the future is inseparable from that of her maternity: maternity matches with the idea of co-creation and virginity with the idea of “radical freedom” that makes it possible.