Immaculate Conception
The Catholic doctrine that Mary was preserved from original sin from the first moment of her conception, through the grace of Christ.
Original sin: In Christian theology, the condition of sin inherited by humanity as a consequence of the Fall. The doctrine specifically teaches that Mary was preserved from this inherited condition.
Feast of the Immaculate Conception: A Catholic solemnity celebrated on December 8 in honor of Mary’s conception without original sin. Liturgical celebration of Mary’s conception preceded the doctrine’s formal definition.
Pope Pius IX: The pope from 1846 to 1878 who defined the Immaculate Conception as dogma in 1854. He formally proclaimed the doctrine in Ineffabilis Deus.
Virgin birth of Jesus: The Christian belief that Jesus was conceived by the Holy Spirit and born of Mary, who had not had sexual relations. It concerns Jesus’s conception, not Mary’s conception, despite the frequent confusion.
Mary, mother of Jesus: The Jewish woman who, according to the New Testament, gave birth to Jesus. The doctrine concerns Mary’s conception and her unique role in Catholic theology.
Duns Scotus: A medieval Franciscan theologian who defended the possibility of Mary’s preservation from original sin through Christ’s merits. His account of preventive redemption helped resolve a major theological objection.
Thomas Aquinas: A thirteenth-century Dominican theologian whose account of Mary’s sanctification did not affirm preservation from original sin at conception. His influential position illustrates the theological disagreement that preceded the definition.
Perpetual virginity of Mary: The Christian doctrine that Mary remained a virgin before, during, and after the birth of Jesus. It is a distinct Marian doctrine, not a claim about original sin.
Grace in Christianity: God’s freely given favor and aid in Christian theology. Catholic teaching attributes Mary’s preservation from sin to divine grace.
Council of Basel: A fifteenth-century council that issued a decree affirming the doctrine of Mary’s immaculate conception. Its 1439 decree marked an influential, though non-final, stage in the doctrine’s development.