The Catholic Church teaches four absolute truths about Mary: that she is the Mother of God; that she conceived and gave birth miraculously, as a virgin; that she was assumed (taken up into heaven) in both body and soul, and that she herself was conceived free from original sin. This “immaculate conception” in the Catholic doctrine is quite often confused with the virginal conception of Jesus, but has a tradition going to the 7th century feasts of Saint Anne (Mary’s mother) and was formally declared a doctrine in the 19th century.

On this day, December 8, in 1854, Pope Pius IX in his papal bull (essentially, a Vatican press release) Ineffabilis Deus declared that Mary was conceived by Saint Anne without Original Sin and with the holy Sanctifying Grace.

Pope Pius IX said in his declaration the doctrine “which holds that the Blessed Virgin Mary, at the first instant of her conception, by a singular privilege and grace of the Omnipotent God, in virtue of the merits of Jesus Christ, the Saviour of mankind, was preserved immaculate from all stain of original sin, has been revealed by God, and therefore should firmly and constantly be believed by all the faithful.”