Over at First Things, Father Edwatd T. Oakes, S.J., has some fascinating reflections on The Immaculate Conception. Read the whole thing.
The theology of it is truly fascinating, particularly the circularity of it:
The juxtaposition of these two titles points to an important feature of all authentic Mariology, one already touched on by Pius IX in Ineffabilis Deus: the circularity of cause and effect in the dispensation of salvation. By that I mean, Mary could not be kept free from sin except by the merits of Christ won on the cross; but of course Christ could not have entered history to save us by dying on the cross except by the free consent of Mary, whose free assent to the angel was a truly graced assent vouchsafed by the future death of her Son.
Of course, what makes this all work is that God exists outside of time, and knows the results of the action of grace ahead of time. In a sense, the Immaculate Conception "worked" because Christ's victory on the cross "worked" -- had Christ rebelled in the desert, he would never have existed, because his mother's Immaculate Conception, and Christ's Virgin Birth, would not therefore have been possible. Had he assented to the Devil's request, he would create the paradox that He could not exist.
Some would argue that this meant that Christ's temptation in the desert was not real -- that because of the Immaculate Conception, the temptation in the desert had no real chance of succeeding. But perhaps it speaks to something more profound than that -- perhaps a successful temptation by the Devil in the desert would have dethroned God. Perhaps the Devil's greatest chance at the ultimate victory was when he asked Christ to make stones into bread, worship the Devil, or jump from the great height.
I have often wondered how the Devil viewed the Virgin Mary, in the days before Christ was born. If he perceived her to be immaculately conceived, he would have to know, if he admitted it to himself, that it meant his rebellion had no ultimate chance of success -- that Mary was made pure because Christ would be made flesh, and therefore mankind would be redeemed. Did he perceive the Virgin Mary to be different from us, and if so, did he understand the implications of why and how she was different? Or did God hide this knowledge from the Devil; in effect veiling the Virgin's Mary's sinlessness from the Devil's view? Did the Devil's own arrogance and pride blind him to the meaning of the Virgin Mary's existence -- which was that Christ would bring mankind to salvation?
And what did the Virgin Mary know of her own state? Even as a child, seeing the sinfulness of people around her, it must have been difficult to understand -- why didn't people simply do what they knew to be right? It must have caused her great pain and sadness to consider the members of her own family, her loved ones, committing sins. Did she view it philosophically, and say "There, but for the grace of God, go I" -- in a truer and more literal sense than any person on Earth ever said it?
And what did Christ know, and when did he know it? Was his state of mind always unique -- even in the cradle, being supernaturally aware of everything around Him? Or did his awareness of his unique state come to him gradually -- reading and hearing Scripture as a child, could he read all the clues and therefore see himself in it, as a man sees his own face on a mirror? If St. Joseph hit himself on the hand with a hammer and swore, did Christ see the pained expression on his mother's face, and understand it in a way somehow different, somehow more, than every other child's experience of an event like this? Did he know that in forgiving St. Joseph for swearing, he was actually forgiving him?
There are thousands of speculations like this one can entertain. Of course, I do not know how profitable any of them are -- it seems to be to be an area that could lead readily into heresy. Like so many things, perhaps it is better than we concentrate on the things which we know to work -- prayer, fasting, and works of charity.