Stephen Bishop of Dori in a Lateran Council, St. Vitalian, the Bishops of the IV. Œumenical Council a.d. 451, St. Agatho in the VI. a.d. 680, St. Bernard a.d. 1153, St. Thomas Aquinas a.d. 1274, St. Bonaventure a.d. 1274: that is, this interpretation is given by three out of the four doctors of the Church, by six Pontiffs down to the seventh century. It was recognised in two Œcumenical Councils. It is explicitly declared by the Angelic Doctor, who may be taken as the exponent of the Dominican school, and by the Seraphic Doctor, who is likewise the witness of the Franciscan; and by a multitude of Saints. This catena, if continued to later times, might, as all know, be indefinitely prolonged.
The interpretation by the Fathers of the words 'On this rock,' &c. is fourfold, but all four interpretations are no more than four aspects of one and the same truth, and all are necessary to complete its full meaning. They all implicitly or explicitly contain the perpetual stability of Peter's faith. It would be out of place to enter upon this here. It is enough to refer to Ballerini De vi et ratione Primatus, where the subject is exhausted.
In these two promises a divine assistance is pledged to Peter and to his successors, and that divine assistance is promised to secure the stability and indefectibility of the Faith in the supreme Doctor and Head of the Church, for the general good of the Church itself.
It is therefore a charisma, a grace of the supernatural order, attached to the Primacy of Peter which is perpetual in his successors.
