In light of today’s readings on this Sunday, and Christ bestowing the papal office on Saint Peter, here is the text of Pastor Aeternus, the dogmatic constitution from the First Vatican Council (1879) defining the limits and extent of the pope’s authority. It is short, and can be read while sipping your coffee.
Here is the final definitive paragraph:
Therefore, faithfully adhering to the tradition received from the beginning of the christian faith, to the glory of God our savior, for the exaltation of the Catholic religion and for the salvation of the christian people, with the approval of the Sacred Council, we teach and define as a divinely revealed dogma that when the Roman Pontiff speaks EX CATHEDRA, that is, when, in the exercise of his office as shepherd and teacher of all Christians, in virtue of his supreme apostolic authority, he defines a doctrine concerning faith or morals to be held by the whole Church, he possesses, by the divine assistance promised to him in blessed Peter, that infallibility which the divine Redeemer willed his Church to enjoy in defining doctrine concerning faith or morals. Therefore, such definitions of the Roman Pontiff are of themselves, and not by the consent of the Church, irreformable.
On this rock, I will build my Church. Christ promised, and He will deliver.
