Motives of credibility

I'd like to examine another argument by Bryan Cross. These are comments he made on his Tu Quoque post:

http://www.calledtocommunion.com/2010/05/the-tu-quoque/

The motives of credibility establish with moral certainty the divine origin and divine authority of the Catholic Church [314]

Here again you’re conflating the period of inquiry and the life of faith, as if what one in the period of inquiry would do entails epistemic equivalence between Protestants on the one hand, and on the other, Catholics living the life of Catholic faith. But a person in the period of inquiry is not in the epistemically equivalent state of the Catholic living the life of faith. Moreover, what would hypothetically serve as a motive of discredibility in the period of inquiry would not be even possible for that entity in which, through the motives of credibility, one may come to divine faith... The Catholic in the life of faith knows that the Church through God’s divine protection cannot teach false doctrine, and is therefore not subjecting the Church’s doctrine to the judgment of his own interpretation of Scripture, but instead allowing the Church to guide and form his interpretation of Scripture.

Again, this conflates the period of inquiry into the motives of credibility, with the life of faith. The person in the stage of inquiry into the motives of credibility is, like the Protestant, not in an epistemic position of acknowledging and submitting to a divinely authorized magisterium. But that does not mean or entail that the Catholic living the life of faith, and thus having come to know and believe in the divine authority of the Church Christ founded, is in the same epistemic condition as the inquirer, or as the Protestant [#324]

i) The issue is whether Bryan's unconditional commitment to Roman Catholicism reflects the mindset of a cult member, where nothing can ever disprove the cult leader. And this isn't just hypothetical. After all, there are lots of religious claimants out there. They can't all be true. 

ii) Bryan endeavors to distinguish between the preconversion stage of inquiry and the postconversion "life of faith" (or "divine faith"). Once an individual converts to Catholicism, he's made an irreversible commitment. Crossed a line of no-return. At that juncture the convert relinquishes his own judgment to the superior judgment of the magisterium. 

iii) One problem with Bryan's position is his claim that "the Catholic in the life of faith knows that the Church through God’s divine protection cannot teach false doctrine." Does a convert to Rome actually know that to be the case–or does he merely believe that to be the case?

Bryan says "the motives of credibility establish with moral certainty the divine origin and divine authority of the Catholic Church."

That's a tremendously strong claim. What does Bryan mean by the "motives of credibility"? Here's out he defines it in another post:

God makes known His voice by way of marks that are unmistakable, i.e. something that only God can do (i.e. miracles). These are what are called the motives of credibility, by which we recognize God’s word as God’s word. (2′)

Motives of credibility allow us to make the transition from human faith to divine faith. (3′)

The motives of credibility allow the act of faith to be reasonable, and make the act of disbelief unreasonable; without them the act of faith would be unreasonable, and would lay us open to superstition. (3′)

Four categories of signs serving as motives of credibility:

(1) miracles, (5′)

(2) prophecies (6′)

(3) the Church (7′)

(4) the wisdom and beauty of revelation itself, and Christ Himself (7′)

The Catechism on the motives of credibility (8′)

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.” (CCC 156)

http://www.calledtocommunion.com/2013/11/lawrence-feingold-the-motives-of-credibility-for-faith/

iv) But how do the motives of credibility, thus defined, single out the church of Rome? Keep in mind that at the stage of inquiry, there's no prior assumption that the motives of credibility point to Rome. Why would an inquirer suppose the argument from miracles or argument from prophecy selects for Roman Catholicism in particular rather than Christianity in general? 

Keep in mind, too, that in church history, up to the present, Roman Catholicism has no monopoly on reported miracles and prophecies. That's paralleled in Protestant circles. 

Likewise, how does (4) select for Roman Catholicism?

At the stage of inquiry, the Catholic identification of (3) is not a given, but something to be established. 

v) Bryan never allows for the possibility that a Catholic convert is sometimes justified in reexamining his conversion. Yet converts have more experience after conversion, and therefore have additional information they didn't have during the preliminary investigation. In that respect, a convert is sometimes in a better position to reconsider his conversion than an inquirer. A convert can make a more informed evaluation by virtue of his postconversion experience. This applies to conversion in general, where converts sometimes have second thoughts after they become better acquainted with the movement/institution/tradition they converted to. 

How it looks from the inside may be dramatically different than how it looks from the outside. With that additional insight, why is he not in a better position than before to judge that he made a mistake? 

To begin with, he may continue his studies upon conversion. And that may lead him to encounter objections he didn't consider beforehand.

In addition, there's a difference between knowledge by description and knowledge by acquaintance. Prior to conversion, he studied an abstract, idealized version of Roman Catholicism. A construct of Roman Catholic theologians and apologists.

But now, based on his firsthand experience, as an insider, he may discover a mismatch between the propaganda and the reality. There's nothing in principle that rules that out. To the contrary, that's assessing Catholicism on the basis of evidence he didn't have at his disposal prior to conversion. He now has a comparative frame of reference.