Our Lady
Immaculate Conception
Marian dogma · defined 1854
Mary, in the first moment of her conception, by a singular grace and privilege of Almighty God, in view of the merits of Jesus Christ, was preserved free from all stain of original sin.
Origin
Defined as dogma by Pope Pius IX in the apostolic constitution Ineffabilis Deus, December 8, 1854. Mary herself confirmed the title to St. Bernadette at Lourdes in 1858: 'I am the Immaculate Conception.'
Why it matters
The dogma affirms that Mary's freedom from original sin was a singular grace of God in view of the merits of Christ. She is the most perfectly redeemed of the redeemed.
Feast day
December 8