A Deductive Argument Against Sola Scriptura...

Sola Scriptura, the Protestant argument that the Bible is the sole basis for the Faith, rather than Church or "the traditions of men", is easily enough refuted. But Protestants of course need it mightily because without it, they have no predicate for being Protestant. I mean, where do they get their authority to interpret the Bible in the first place? Did our Lord breathe on them at some point, and say, "Receive ye the Holy Ghost! Whatsoever ye declare bound on Earth shall be bound in Heaven?" (St. John 20:22-23) 

Well, actually, Calvin seems to have thought he was a prophet or new apostle, or so I understand. (I remember hearing that somewhere, but Calvinists don't broadcast it, much like Luther's many versions of "Logic is the devil's whore" or "the Christian must pluck out reason from his mind as one plucks out an eye.") 

Were I ever in a formal debate with Protestants, that's the first question I would ask. "Where do you get the authority to teach – anything?" They'd have to refer to Sola Scriptura, or go home. 

While various Bible verses have been used in varying degrees to argue for Sola Scriptura, it is usually 2 Timothy 3:15-16 that is invoked. It reads, starting with verse 14: "4 But continue thou in those things which thou hast learned, and which have been committed to thee: knowing of whom thou hast learned them; 15 And because from thy infancy thou hast known the holy scriptures, which can instruct thee to salvation, by the faith which is in Christ Jesus. 16 All scripture, inspired of God, is profitable to teach, to reprove, to correct, to instruct in justice," (The relevant section I've bolded and italicized) 

This version is the Douay-Rheims. This following are verses 15 & 16 from the New International Version: "...And how from infancy you have known the Holy Scriptures, which are able to make you wise for salvation through faith in Christ Jesus. 16 All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness...".

Pretty close, the two versions. The Catholic version says "profitable" where the Protestant version has "useful", The Catholic version has "can instruct thee to salvation" whereas the Protestant one has the more colorful "make you wise for salvation." The Greek I have, too. 

In any event, nowhere do these verses suggest that Scripture alone is what salvation or the Faith in general, are based on. And in other places, St. Paul writes (2 Thessalonians 2:15):  "So then, brothers and sisters, stand firm and hold fast to the teachings we passed on to you, whether by word of mouth or by letter."

Such a passage obviously undercuts any Sola "Scriptura" idea. But my deductive argument against Sola Scriptura is based on 1 Timothy 3:15 which reads in the NIV: "If I am delayed, you will know how people ought to conduct themselves in God’s household, which is the church of the living God, the pillar and foundation of the truth." Call me an unreformed type, but I like the Douay-Rheims English better: "But if I tarry long, that thou mayest know how thou oughtest to behave thyself in the house of God, which is the church of the living God, the pillar and ground of the truth."

Anyway, here's the deductive argument. Premise one (major premise): 1 Timothy 3:15 shows that St. Paul the wordsmith capability, the phrasing, words, grammar, etc., to have written "If I am delayed, you will know how people ought to conduct themselves in God’s household, which is the Scripture of the living God, the pillar and foundation of the truth."

Premise two (minor premise): In all of the vast corpus of Pauline text, the "Apostle to the Gentiles" does not in fact write any such passage, not remotely, as shown so well in 2 Timothy 3:15-16. 

Conclusion: St. Paul did not in fact communicate any such idea because he did not want to. He had the ability, and the space, but he didn't. It was not his teaching.

Simple. 

We hardly need get into the demented inbreeding of First-order logic (a.k.a. predicate logic, quantificational logic, and the so whimsically named "first-order predicate calculus" or its papa (or would it be "mama"?) propositional logic (also called symbolic logic and Our Lord only knows what else), to conclude St. Paul had means and opportunity to "do the deed" regarding Sola Scriptura, but not the motive. 

He wasn't a Protestant.

An Préachán