Recently in a comment, he provided the first linkage I’ve seen that, in his mind, provides some kind of evidence that the Roman Catholic Church is what he always simply assumes it to be:
The motives of credibility indicate the location and identity of the Church Christ founded, and they are accessible to human reason.
Note the phrase “motives of credibility”. Here’s what that means, according to the Catholic Encyclopedia:
These testimonies are unanimous; they all point in one direction, they are of every age, they are clear and simple, and are within the grasp of the humblest intelligence. And, as the Vatican Council has said, "the Church herself, is, by her marvellous propagation, her wondrous sanctity, her inexhaustible fruitfulness in good works, her Catholic unity, and her enduring stability, a great and perpetual motive of credibility and an irrefragable witness to her Divine commission" (Const. Dei Filius) . "The Apostles", says St. Augustine, "saw the Head and believed in the Body; we see the Body let us believe in the Head" [Sermo ccxliii, 8 (al. cxliii), de temp., P.L., V 1143]. Every believer will echo the words of Richard of St. Victor, "Lord, if we are in error, by Thine own self we have been deceived—for these things have been confirmed by such signs and wonders in our midst as could only have been done by Thee!" (de Trinitate, 1, cap. ii).
Here the concept is found in CCC 156:
What moves us to believe is not the fact that revealed truths appear as true and intelligible in the light of our natural reason: we believe "because of the authority of God himself who reveals them, who can neither deceive nor be deceived". So "that the submission of our faith might nevertheless be in accordance with reason, God willed that external proofs of his Revelation should be joined to the internal helps of the Holy Spirit." Thus the miracles of Christ and the saints, prophecies, the Church's growth and holiness, and her fruitfulness and stability "are the most certain signs of divine Revelation, adapted to the intelligence of all"; they are "motives of credibility" (motiva credibilitatis), which show that the assent of faith is "by no means a blind impulse of the mind".
But these things “indicate the location and identity of the Church Christ founded”.
Bryan’s excellent adventure continues.