Well apparently someone else thinks he understands Roman Catholicism without reading Church documents. If he had taken time to read even this one document, he wouldn’t sound so off-base. It is on the Vatican website, no less. For another helpful interaction with this issue, see Raymond Brown’s (a pope appointed member of the Pontifical Biblical Commission more than once) wonderful book The Critical Meaning of the Bible. The document explains how theologians should handle matters in which they disagree with the Magisterium. For those who might not like to read the whole thing, I’ll summarize a few points:
1. Theologians who disagree with the Magisterium should not present their views as unarguable conclusions. In other words, they admit to the fact that they could possibly be wrong and the Magisterium right.
2. Disagreements must be based on argumentation that seems well-founded to the theologian. In other words, theologians cannot reject the teaching of the Magisterium simply because it doesn’t suit them.
3. Theologians should make sure that they truly understand the teaching of the Magisterium. In other words, they are not disagreeing with a misunderstanding of the teachings of the Magisterium.
4. Theologians should address disagreements in the proper context, i.e. within the Church and not within the mass media.
5. If the disagreement persists (and yes, the document does allow for the fact that a disagreement can genuinely persist), the theologian remains open to the teaching of the Magisterium, though they may not accept it.
Perhaps this is not pure unbridled freedom of Protestant scholarship (*chortle*), but at least for me as a Roman Catholic, I find it helpful that there is official Church teaching on how to handle disagreements, rather than approach I’ve seen some Protestants in my area use of simply starting a new church. There are other important points in this document. But, this may suffice to show that the person who wrote the post I linked to has a very weak and inaccurate understanding of the function of the Magisterium – “For example, if a Roman Catholic is interpreting the Scriptures, he must come to conclusions that are in line with what Rome has already said about the subject.” Well, not according to this document on the Vatican website (overseen by Joseph Ratzinger back in the 1990s).
PS – This is not even to mention the fact that the Church doesn’t emphatically define every single solitary doctrinal issue, e.g. priestly celibacy in the Latin Rite and married priests at the parish level in the Eastern Rite.