…after presenting without interruption, in humility and fasting, Our personal prayers and the public prayers of the Church, to God the Father through his Son, so that He would deign to direct and confirm Our mind with the virtue of the Holy Spirit; after having implored the assistance of the entire celestial Court and after having invoked the Paraclete Spirit with groans; by his divine inspiration, in honor of the saint, and indivisible Trinity, as a decoration and ornament of the Virgin Mother of God, to the exaltation of the Catholic Faith and to the increase of the Christian Religion, with the authority of Our Lord Jesus Christ, of the Holy Apostles Peter and Paul and Ours, we declare, we affirm and define as revealed by God the doctrine which holds that the most blessed Virgin Mary was preserved, by the particular grace and privilege of almighty God, in anticipation of the merits of Jesus Christ, Savior of the human race, immune from any stain of original sin from the first moment of his conception, and this must therefore be a certain and immutable object of faith for all the faithful.
Who the Constitution of the Ineffable God of Pius IX