successor of Peter, prince of the Apostles, holds over the Church. For the Fathers of the Fourth Council of Constantinople, treading in the footsteps of their pre- decessors, made this solemn profession : Salvation firstly consists in keeping the rule of the true faith. And since we cannot set aside the saying of our Lord Jesus Christ, Thou art Peter, and upon this rock I will build my Church, these things which have been said are proved in effect, because in the Apostolic See the Catholic religion has ever been maintained stain- less, and her celebrated teaching holy. Hence, desiring not to be separated in any way from this faith and doctrine, we hope that we may deserve to be in the one communion, which the Apostolic See preaches, in which is the whole and true solidity of the Christian religion. And, with the approval of the Second Council of Lyons, the Greeks made this profession : The holy Roman Church has supreme and full sovereignty o the whole Catholic Church, which sovereignty it truly and humbly recognises that it has received with the fulness of power from the Lord himself, in the person of blessed Peter, prince and head of the Apostles, whose successor is the Roman Pontiff ; and as it is bound before all others to defend the truth of faith, so also, if any questions concerning the faith arise, they should be defined by its judgment.