The Formal Doctrine of the Immaculate Conception Was Proclaimed by Pius IX
The formal doctrine of the Immaculate Conception, affirming the freedom of the Blessed Virgin from sin from the very moment of her conception, was proclaimed by Pius IX on December 8, 1954 in the document Ineffabilis Deus. The document included the following statement, translated from Latin: “We declare, pronounce, and define that the doctrine which holds that the most Blessed Virgin Mary, in the first instance of her conception, by a singular grace and privilege granted by Almighty God, in view of the merits of Jesus Christ, the Savior of the human race, was preserved free from all stain of original sin, is a doctrine revealed by God and therefore to be believed firmly and constantly by all the faithful.”