One of the most common mistakes that Catholics make regards what is actually celebrated during this week’s feast of the Immaculate Conception.  The general consensus is that it is a feast marking the Immaculate Conception of Jesus.  They this feast with the Feast of the Annunciation which marks the miraculous manner in which the Word took flesh in the womb of the Immaculate Conception.  One thing they are not wrong about however is that, while the feast centers on the circumstances and consequences of Our Lady’s singular grace, the Feast, like all things pertaining to Our Lady really is about Christ.

The Council of Chalcedon in 451 was called in response to the Monophysite heresy.  This heresy believed that the two natures of Christ were united such that they really became one, that is, the human was fully absorbed by the divine rendering only a single nature. Its backers proposed the metaphor that the divine nature was like an ocean and His human nature like a drop of water totally lost in the divinity.  This may seem to be unnecessary theological hairsplitting until we follow through to its logical conclusions.  First, with no true humanity, He would only appear to be human like some sort of vision or hologram.  Second, and more importantly, it meant that the humanity of Christ could not be a separate source of activity from the divinity.  He could not really suffer and die as a man and any appearance of those things would be only that, an appearance.

The Council, with the approval of St. Leo the Great, was quick to reject any trace of this and reaffirmed that Christ ss true God and true man, “perfect in divinity and perfect in humanity, the same truly God and truly man, composed of rational soul and body; consubstantial with the Father as to his divinity and consubstantial with us as to his humanity; ‘like us in all things but sin.’. He was begotten from the Father before all ages as to his divinity and in these last days, for us and for our salvation, was born as to his humanity of the virgin Mary, the Mother of God” (quoted in CCC 467).

The necessity of both powers of operation, human and divine, are necessary for Christ’s sacrifice to be efficacious.  Remove either power and atonement becomes a sham.  Mankind incurred a great debt, so great that only God could pay it.  Justice must be served for the moral order of the universe to be restored.  In mercy, God takes the debt as if it is His own.

Christology and the Immaculate Conception

What does all this have to do with the Immaculate Conception?  As true man, Christ was “born of a woman” (Gal 4:4).  That is self-evident, but it also means His mother was a true mother.  And like all mothers, she supplied to Him her flesh and it was her blood that coursed through His veins.  Put in a more scientific manner, it was her ovum that was fertilized and that ovum became the building block of the human nature that was assumed by the Person of the Son.  She was truly His mother and not merely a surrogate or a human incubator.

Furthermore, we are told that the Son of God come in the flesh is “like us in all things but sin” (Heb 4:15), that is, neither original nor actual sin touched Him.  The impossibility of actual sin we all intuitively grasp, but we may not think about the fact that the human nature He inherited must also be free from original sin and its effects.   Original sin is not sin committed, but “sin” inherited.  It is passed down from our parents.  Since Our Lord had only one human parent, and she was truly His Mother and no mere surrogate, the flesh that Mary passed down to Him had to be free from original sin and its effects.

We begin to now see the logic of the Immaculate Conception as an explanation for the purity of His blood offering and His freedom from Original Sin.  We have ruled out the possibility that by some miraculous intervention the ovum that was to become a part of Our Lord’s human nature was altered at the moment of Conception.  Mary would no longer be His true mother.  But we have not yet seen why Our Lady must be free from the stain of Original Sin from the moment of her conception.  Why could it not be that she was sanctified at some other time?

When Pope Pius IX declared the dogma of the Immaculate Conception in 1854, he commented on the fact that it was “wholly fitting that so wonderful a mother should be ever resplendent with the glory of most sublime holiness and so completely free from all taint of original sin.”  In other words, he thought it was not theologically necessary, only fitting.  But there may be a certain biological necessity that would help us to see why this dogma is true.

How Science Supports the Immaculate Conception

Thanks to advances in the field of human embryology, we know that the flesh of Our Lord (in Mary’s oocytes) was actually formed at her conception. Although He takes her flesh at the Annunciation, but the actual flesh He takes to Himself (in the oocyte that matured into an egg) was present in Mary at her beginning.  Just as she carried it around after His birth, Mary was, in a very real sense, carrying around the flesh of Our Lord from the moment of her conception.

For the more scientifically minded, we know that at the moment of conception, although obviously not fully formed, the human person is self-directed and thus needs no outside intervention to develop assuming the proper environment.  That means that even if oogenesis occurs at the meiosis I stage of development, everything that is to be used for the formation of those germ cells is already present.  We should make sure that we see development as a continuous process, begun in a definitive direction at conception, and not a series of independent stages.  The stages are simply mental constructs to help us understand the development itself.

Science then would help to confirm that the Immaculate Conception is necessary, even if theology can only describe its fittingness.  Science is a path not just to facts but to wonder, a sure path to the Truth.  The dust from the earth shattering landing of the Son of God has yet to settle, leaving traces of Him everywhere we look.  Science is no threat to our devotion but a means of increasing it.

This realization can also help to increase our devotion in another way.  According to Josephus, the great Jewish historian, the restoration of the Second Temple of Zerubbabel began in the year 19BC.  This is the same year that tradition also says Our Lady was born.  That is, at the same time that Herod set out to rebuild the Temple, God began construction on the true Temple.  The cornerstones of the Temple of Our Lord’s body were laid at the moment of Our Lady’s Conception, of that truth science confirms.

As Friday’s Feast Day comes around, we can be sure that there will be many Catholics confused as to who the Immaculate Conception refers to; thinking it refers to Jesus’ conception and not Our Lady’s.  But they are not entirely wrong—Our Lady, in whom the true Temple was made, carried around the building blocks with her from the moment of her own conception.

Our Lady, conceived without sin, pray for us who have recourse to thee!