“Among the descendants of Eve, God chose the Virgin Mary to be Mother of His Son. “Full of grace”, She is “the most excellent fruit of Redemption “: from the first instant of her conception, was entirely preserved from stain of original sin and immune from personal sin during her life”. This is affirmed in number 508 of the Catechism of the Catholic Church with regard to the dogma of the Immaculate Conception.
Again in these terms the Catechism of the Catholic Church says “the Blessed Virgin from the first instant of her conception through singular grace and privilege granted by Almighty God, in view of the merits of Jesus Christ Saviour of the human race, was preserved immune from stain of original sin”. And this doctrine “a Deo revelata atque idcirco ab omnibus fidelibus firmiter constanterque credendam (esse)”.
At the basis of the dogmatic definition there is the theological presupposition that Mary, descending from Adam through natural generation should have, like all men, contracted original sin. But she was given a special privilege to become a “worthy home of God”: if all mankind were liberated from original sin by Jesus Christ after contracting it, Mary was preserved from contracting it. This unique exception to a common law was solemnly defined by the Church as revealed by God and therefore contained in the sources of Revelation.
This dogma, because of its many connections with theological and pastoral matters and ecumenical implications has assumed great importance in theology and in the life of the Church.
In the history of dogmas that of the Immaculate Conception is unique because it was defined by Pius IX not so much because of proofs in Scripture or ancient tradition, but due to a profound sensus fidelium and the Magisterium.
“ … So the Church in her doctrine, in her life and her worship, perpetuates and transmits to all generations what she is and what she believes. This Tradition of apostolic origin develops in the Church with the assistance of the Holy Spirit: there is growing understanding of things and words, through contemplation and study of the laity who ponder these things in their heart (cfr. Lk 2,19 e 51), with intelligence coming from profound experience of spiritual things, and trough preaching of those who through Episcopal succession have received a charisma of truth. So in the centuries the Church tends unceasingly to the fullness of divine truth so that in it the words of God may be brought to completion”.
This text of Dei Verbum, 8 would appear to respond best to the context which generated the dogmatic definition of the Immaculate Conception. It is the Holy Spirit who matures sensus fidei of the Christian people enabling it to a spontaneous understanding of the revealed fact and inward maturing of the fact thanks to reflection, experience and preaching.
The Immaculate Conception is a liturgical feast which has sometimes been wrongly understood by the faithful who mistakenly think it refers to Mary’s conception of Jesus, rather than the absence of sin in the soul of Mother of God’s from the moment of her conception.
The dogma of the Immaculate Conception is also a point of difficulty in ecumenical dialogue with Protestants and Orthodox Christians. Although the latter are in agreement substantially with the West with regard to the mystery of the Mother of God, they find it difficult to accept the dogma, at least as it was formulated in 1854, because it contains expressions which appear to refer to an arbitrary action of God.
Protestants for their part, reject the definition on the grounds that there is no clear and certain basis for it to be found in Sacred Scripture and even more because the dogma places Mary out of the reality of sin, proper to man and shows that Jesus was not her Saviour.
Lumen Gentium, number 53 replies to this objection: “The Virgin Mary, who at the message of the angel received the Word of God in her heart and in her body and gave Life to the world, is acknowledged and honored as being truly the Mother of God and Mother of the Redeemer. Redeemed by reason of the merits of her Son and united to Him by a close and indissoluble tie, she is endowed with the high office and dignity of being the Mother of the Son of God, by which account she is also the beloved daughter of the Father and the temple of the Holy Spirit. Because of this gift of sublime grace she far surpasses all creatures, both in heaven and on earth. At the same time, however, because she belongs to the offspring of Adam she is one with all those who are to be saved. She is "the mother of the members of Christ . . . having cooperated by charity that faithful might be born in the Church, who are members of that Head."(» (…)”.
Earlier in Fulgens Corona Pius XII wrote: “10. If these praises of the Blessed Virgin Mary be given the careful consideration they deserve, who will dare to doubt that she, who was purer than the angels and at all times pure, was at any moment, even for the briefest instant, not free from every stain of sin? Deservedly, therefore, St. Ephrem addresses her Divine Son in these words: "Really and truly Thou and Thy Mother are alone entirely beautiful. Neither in Thee nor in Thy Mother is there any stain." (Carmine Nisibena, Ed. Bickell, 123). From these words, it is clearly apparent that there is only one among all holy men and women about whom it can be said that the question of sin does not even arise, and also that she obtained this singular privilege, never granted to anyone else, because she was raised to the dignity of Mother of God.11. This high office which the Council of Ephesus solemnly declared and sanctioned against the heresy of Nestorius (Cf. Pius XI, Encyclical Lux Veritatis; Acta Apost. Sedis, Vol. 23, P. 493, ss) and greater than which does not seem possible, demands the fullness of Divine grace and a soul immune from stain, since it requires the greatest dignity and sanctity after Christ. Yea indeed, from this sublime office of the Mother of God seem to flow, as it were from a most limpid hidden source, all the privileges and graces with which her soul and life were adorned in such extraordinary manner and measure.12. For as Aquinas correctly states: "The Blessed Virgin, because she is the Mother of God, has a certain infinite dignity from the infinite good, which is God" (Cf. Summa Theologiae, I, Q, 25, Art 6 as 4um). And a distinguished writer develops and explains this in these words: "The Blessed Virgin . . . is the Mother of God: therefore, she is the purest and the most holy, so that under God a greater purity cannot be understood" (Cornelius a Lapide, In Matth. 1.16).».
In the history of the dogmatic definition of the Immaculate Conception, without a doubt, sensus fidei takes precedence over theology which delayed, weighing the pros and cons of the Marian privilege.