Earlier quoted context omitted.
> How could they know? I can’t speak for any religious leader but in terms of Catholic leadership: because in many matters God spoke through the Prophets and then He came down and told us directly which is preserved in Holy Scripture and Sacred Tradition (2 Thessalonians 2:15-17), and the Holy Spirit guides the Church (John 14:26) and does so through the prime ministerial office of the Pope the successor of Peter (Ma…
Granting it's been 30 years since I've considered myself Catholic, so speaking entirely from the perspective of a non-believer at this point, but to me, the central dilemma is say I buy that we and our universe have a thinking, feeling creator that watches events, possibly intervenes, and actually cares how we behave in a way we can translate into human language and moral directives, given all the thousands upon thou…
My understanding of Catholicism comes from outside of it, but this isn't how I understand Catholic epistemology—this sounds more like Sola Scriptura, which is a Protestant doctrine and emphatically not a Catholic one.
Since I'm not a Catholic, I'm going to link out to an explanation from people who are [0]:
> The living magisterium, therefore, makes extensive use of documents of the past, but it does so while judging and interpreting, gladly finding in them its present thought, but likewise, when needful, distinguishing its present thought from what is traditional only in appearance. It is revealed truth always living in the mind of the Church, or, if it is preferred, the present thought of the Church in continuity with her traditional thought, which is for it the final criterion, according to which the living magisterium adopts as true or rejects as false the often obscure and confused formulas which occur in the monuments of the past. Thus are explained both her respect for the writings of the Fathers of the Church and her supreme independence towards those writings; she judges them more than she is judged by them.
So the epistemological problem to resolve is not why these particular documents, it's why this particular organization? Not why do I trust what's written here but not there—the answer to that is because the Church says so—but why do I trust this Church?
Not being a Catholic, I can't really answer that question, but I do think it's important to approach the Catholic question on its own terms rather than Protestant terms.
[0] https://www.catholic.com/encyclopedia/tradition-and-living-m...