It seems to me that you require a level of assurance which is by sight and not by faith when it comes to the leading of the Church by the Holy Spirit.
It seems to me that this perspective on the question has things almost exactly backwards in significant ways. Consider: with respect to doctrine, the Reformed Protestant claims that he only accepts as true what is written in Scripture. But he goes further than that. He also says that this can only be determined by means of grammatical-historical interpretation of the Bible. And he goes further still than this: he also insists that the literal meaning of the Bible is “one” (WCF I.ix): that is, what God means or intends by a passage is the same as what the human author meant or intended by it.
Now, all this being the case, how is this not an assurance of the truth that is obtained “by sight”? In truth, this entire methodology revolves around man: Scripture’s content is what was intended by man, and its meaning is that which is discoverable by man, and because churches and councils may err (WCF XXXI.iv), each man must ultimately decide for himself what the meaning of the Bible is. Man becomes the measure of the content of revelation.
I would assert that this Protestant model is far better described as “assurance which is by sight” precisely because it is an assurance founded upon what a man sees for himself in the Bible.
In contrast, the Catholic is expected to assent to things he might not even understand. For example, I do not understand the doctrine of transubstantiation. I have read multiple explanations, but I still don’t get it. I have read St Thomas’ explanation, but it’s way over my head. Nevertheless, I believe it because the Catholic Church teaches it: I believe it by faith. How is this “assurance which is by sight”?
Zoltan continues, in an effort to buttress the previous assertion:
If Christ were visible on this earth and leading us with infallible decrees, things would be clear and easy for all.
And yet Christ actually was visible on this earth, and many of His disciples abandoned Him because of what He infallibly taught in John 6:30-71. All but a handful of them disappeared at the crucifixion. St Peter denied that he even knew Him. St Thomas flatly said he wouldn’t believe without tangible proof. The Israelites saw the plagues on Egypt, and they saw the parting of the Red Sea, and they heard the Voice of the Living God forbidding them from worshiping other gods, and they still made the golden calf.
So we see that things should not be expected to be “clear and easy” simply because the Magisterium occasionally makes infallible proclamations concerning faith and morals.
All our knowledge is contingent and ultimately rests on some faith proposition of “authority”.
It appears that Zoltan is a presuppositionalist. But his assertion here is incorrect. We know, apart from any faith proposition, that a whole is greater than any of its constituent parts. We know, apart from any faith proposition, that “A” and “non-A” cannot both be said to be true at the same time and in the same respect. We know, apart from any faith proposition, that the sun is shining in the sky.
Herein lies the issue. Rome promises to sort out all the theological quandaries with infallible decrees.
The Magisterium does not promise to do such a thing. Here is what the Catechism says:
In order to preserve the Church in the purity of the faith handed on by the apostles, Christ who is the Truth willed to confer on her a share in his own infallibility. By a “supernatural sense of faith” the People of God, under the guidance of the Church’s living Magisterium, “unfailingly adheres to this faith.”
The mission of the Magisterium is linked to the definitive nature of the covenant established by God with his people in Christ. It is this Magisterium’s task to preserve God’s people from deviations and defections and to guarantee them the objective possibility of professing the true faith without error. Thus, the pastoral duty of the Magisterium is aimed at seeing to it that the People of God abides in the truth that liberates. To fulfill this service, Christ endowed the Church’s shepherds with the charism of infallibility in matters of faith and morals (CCC §§889-890).
The Magisterium does not exist for the sake of answering just any question. It is not a Magic 8-Ball for theology. There will always be questions that it does not (and cannot) answer, precisely because God is infinite. We cannot fathom Him with our finite minds.
However, the Scripture commands us to submit to all earthly authorities as well (eg: government, wives to husbands etc.) Are those authorities infallible? Is it possible for a Christian to decline to submit if that authority has crossed a boundary which scandalizes the conscience of that person or contravenes a commandment of God?
Scripture does indeed command us to submit to earthly authorities. But Zoltan erroneously identifies the Magisterium’s authority with that of mere human institutions (to whom we may say (verse 29), when necessary, “We ought to obey God rather than men”). But the Church is not a mere human institution. It is the Body of Christ. Consequently the two cases are not congruous, and the fact that we may under certain grave circumstances disobey earthly authorities does not mean that the Church’s teaching concerning faith and morals is fallible.