On July 18, 1870, despite the overwhelming, hysterical and desperate protest in the press all over the world, the Dogmatic Constitution Pastor Aeternus, defining the infallibility of the Pope, was adopted. On that day, the Holy Father, Pope Pius IX, solemnly defined with the words of infallibility, which are explained in the following:
“Faithfully adhering to the tradition received from the beginning of the Christian faith, for the glory of God our Saviour, the exaltation of the Catholic religion, and the salvation of the Christian people … the sacred Council approving … we teach and define that it is a dogma divinely revealed: that the Roman Pontiff, when he speaks ex cathedra – that is, when in the discharge of the office of pastor and teacher of all Christians, by virtue of his supreme Apostolic authority, he defines a doctrine regarding faith or morals to be held by the Universal Church – is, by the divine assistance promised him in Blessed Peter, possessed of that infallibility with which the Divine Redeemer willed that His Church should be endowed for defining doctrine regarding faith or morals; and that, therefore, such definitions of the Roman Pontiff are ireformable of themselves and not from the consent of the Church.
A violent thunderstorm, threatening since early morning, broke over Rome just as the voting on the doctrine began. For an hour and a half, peals of thunder shook the vast basilica, and flashes of lightning lit up the faces of the Fathers as each rose, in his turn, to give his assent. The altar appeared out of the pitch darkness as the lightning lingered on it.
The people were filled with awe as Our Lord’s words to Saint Peter, ” Thou art Peter, and upon this Rock I shall build My Church” … which were inscribed on the dome … suddenly stood out clearly for all to read. To many present it recalled the thunders which rolled and the lightnings which flashed around Sinai, while Moses within the storm cloud on the mountain top received the law from the eternal God.
Freemasonry in the Life and Times of Pope Pius IX Father Leonard Feeney