But, still more extraordinary, this Church, which has no proof of anything she says beyond her own bare assertion, is making converts, in an enlightened country like ours [UK], at the rate of some twelve thousand in the year. How does she manage (one wonders) to play off her confidence trick with such repeated success?

This is, indeed, a phenomenon at which non-Catholics profess to feel the utmost astonishment. But it is a kind of astonishment which has grown blunted by usage; they have come to regard it as part of the order of things that their neighbours should become the victims, now and again, of this extraordinary tour de force. If they were compelled to picture to themselves the process of a conversion, they would, I suppose, conceive it something after this fashion - that the mind of the inquirer is hypnotized into acquiescence by the crafty blandishments of a designing priest; not by his arguments, for he has none, he only goes on shouting "Become a Catholic, or you will go to hell!"; not by his arguments, but by some fatal quality of fascination, which we breed, no doubt, in the seminaries. In a dazed condition, like that of the bird under the snake's eye, he assents to every formula presented to him, binds himself by every oath that is proposed to him, in one open-mouthed act of unreasoning surrender. After that, of course, pride forbids him to admit, so long as life lasts, that the choice so made was a mistaken one; besides, one knows the power these priests have. Yes, it is very curious, the power attributed to their priests. When you have had the privilege of assisting at their education for seven years, you feel that "curious" is too weak a word for it.

This is, presumably, what Protestants have in mind when they represent submission to the Church as a form of "intellectual suicide." They mean that the act of faith which a man makes in joining the Church is an act of the will (or, more properly speaking, the emotions), with frequent allusion to the misunderstood text, "With the heart man believeth unto salvation"; whereas their Catholic opponents earned bitter hatred by insisting that the act of faith, however much directed by the will, had its seat in the intellect. Historically, Protestantism is committed to the notion that the act of faith is the mere surrender of a personality to a Personality, without parley, without deliberation, without logical motive. The true representative of Protestantism in the modern world is the Salvationist who stands up at a street corner and cries out "I am saved." It is Catholicism which insists that, ideally at least, it is the intellect which must be satisfied first, the heart afterwards. -- Ronald Knox, The Belief of Catholics, ch. 3, "Telling the First Lie"

How is it that we profess to hold with absolute certitude the revealed truths of our religion? Reasonable enough to say that if your Church is infallible, the doctrines which she preaches are evidently true, and capable of producing absolute certitude in the mind. But the infallibility of your Church is not a self-evident axiom; it is a proposition which you have proved, and proved it by an appeal to ordinary human reason. Is it not clear, then, that in the last resort every statement which your Church makes rests upon the validity of the arguments by which, in the first instance, you proved your Church infallible? Now, these arguments, based as they are upon human reason, do not convey absolute certitude to the mind; they may be, in your view, overwhelmingly probable; nay, they may be certain with all human certainty; but human certainty is not absolute certainty. … You cannot prove the existence of God, the authority of Christ, or his commission to his Church, beyond all possibility of doubt; how then can you suppose that you have proved beyond all possibility of doubt the statements which you receive on the Church's authority?

The motives of credibility, satisfying his intellect, bring the inquirer up to the point of making the act of faith. That act recognizes God's authority in the Church's teaching; and the absolute nature of his authority does make all the difference to the kind of certitude with which, thenceforward, he holds the truths of Catholic doctrine. But this is inherent in the act of faith, not in the chain of proof by which the Catholic claim is established. Having made the act of faith, he cannot produce more or better arguments to convince his neighbour than he could have produced before. Apologetically, then, revealed truths have no higher certitude than the arguments by which the fact of revelation is established. The revealed proposition that there are Three Persons in the Blessed Trinity is not, apologetically, more certain than the statement that our Lord left the charisma of infallibility to his Church. … The absolute certainty with which we believe the teaching of the Church comes to us from the supernatural grace of faith, which transforms our reasoned conviction into a higher quality - the water, as at Cana, is turned into wine.

- Msgr. Ronald Knox, The Belief of Catholics

For three centuries the true issue between the two parties was obscured, owing to the preposterous action of the Protestants in admiring Biblical inspiration. The Bible, it appeared, was common ground between the combatants, the Bible, therefore, was the arena of the struggle; from it the controversialist, like David at the brook, must pick up texts to sling at his adversary. In fact, of course, the Protestant had no conceivable right to base any arguments on the inspiration of the Bible, for the inspiration of the Bible was a doctrine which had been believed, before the Reformation, on the mere authority of the Church; it rested on exactly the same basis as the doctrine of Transubstantiation. Protestantism repudiated Transubstantiation, and in doing so repudiated the authority of the Church; and then, without a shred of logic, calmly went on believing in the inspiration of the Bible, as if nothing had happened! Did they suppose that Biblical inspiration was a self-evident fact, like the axioms of Euclid? Or did they derive it from some words of our Lord? If so, what words? What authority have we, apart from that of the Church, to say that the Epistles of Paul are inspired, and the Epistle of Barnabas is not? It is, perhaps, the most amazing and the most tragic spectacle in the history of thought, the picture of blood flowing, fires blazing, and kingdoms changing hands for a century and a half, all in defense of a vicious circle.

The only logic which succeeded in convincing the Protestants of their fallacy was the logic of facts. So long as nobody except scoffers and atheists challenged the truth of the scriptural narratives, the doctrine of inspiration maintained its curiously inflated credit. Then Christians, nay, even clergymen, began to wonder about Genesis, began to have scruples about the genuineness of 2 Peter. And then, quite suddenly, it becomes apparent that there was no reason why Protestants should not doubt the inspiration of the Bible; it violated no principle in their system. The Evangelicals protested, but theirs was a sentimental rather than a reasoned protest. … For three centuries the inspired Bible had been a handy stick to beat Catholics with; then it broke in the hand that wielded it, and Protestantism flung it languidly aside.

The Belief of Catholics, Knox, 1927. pp. 113-114.