Sola Scriptura vs Sola Dei Verbum

What is Scripture? Scripture has a dual nature, that it was caused by man and caused by God. We accurately say that John wrote John's Gospel, and we accurately say God wrote it too. Scripture then, not being only from God, is simply the teachings of the Apostles in written form, protected from error by God. But if these teachings were inspired and protected from error by God in written form, why not think the same protection is given in oral form since the oral produced the written? An effect cannot be greater than its cause. So then, we ask, is there more to the teachings of the Apostles than what was written down? Certainly, for Scripture itself says so in John 21:25, that there are many things that Jesus did that have not been recorded. If the substance of Scripture is what the Apostles taught, and some teachings were not written down, then it follows that there is some substance of inspired word that is not found in Scripture. These teachings, preserved by God from error as they were when they were written, are called Sacred Tradition. This is extra-Biblical authority that is still necessary to preserve and is authoritative with equal footing as Scripture. Therefore, Sola Dei Verbum is true. If Sola Scriptura is false, then Sola Dei Verbum becomes more plausible. After all, we need some sort of infallible authority. If Sola Scriptura were true, then we should see some Biblical support for this. We do not. Therefore Sola Scriptura is self-refuting and thereby false. Therefore, Sola Dei Verbum is more plausible. I acknowledge that philochristos has cited 1st Timothy as an attempt to justify Sola Scriptura. This is a non-sequitur. Let me flesh this out by asking, What does philochristos mean by "sufficient"? The claim that Scripture exists to equip us for every good work does not entail that Scripture is all that is needed to equip us thoroughly for every good work. After all, plainly, lots of other things are needed, like air, food, water, intellectual skills, and God's grace. There is another problem with this vague meaning of "sufficient". It would follow that Scripture would have too much for us to be equipped and redundancies would occur in Scripture. If I were to ask philochristos, How many times does God have to say something in order for you to believe it? I'm sure in his obedience and piety he would say only once. Ah, well then, doesn't it follow that it is permissible to get rid of parts of the Bible that repeat itself, like the multiple accounts of the life of Jesus or his death? After all, only reading about it once is sufficient! But that would be absurd. And here, Catholics, like myself, would agree. Even if Scripture were granted that it was "sufficient", whatever that means, it does not follow that it stands alone. It is not permissible to drop and lose any teachings even if they are not found in the Bible. So even if Scripture were sufficient to equip us for every good work, it would not follow that Scripture contains all true, Christian doctrine. This is a non-sequitur from philochristos, and Sola Dei Verbum is more plausible. Finally, you need the authority of the Church or Sola Dei Verbum, to justify knowing Scripture. If I were to ask philochristos, How do you justify inspiration? he might appeal to 1st Timothy once again. I've already expressed concerns about this approach, but in addition, it would be circular. Philochristos may appeal to the historical-critical account, but that would not follow, no matter how successful he is, for all that does is justify the claim that such events actually happened, and are true (and what can determine to be true is limited to mostly events and not doctrine) but that would in no way ever justify the claim of inspiration. The difference is this: all things that are inspired are true, but not all things that are true are inspired. For example, 2+2=4 is true, but it isn't inspired revelation. Because God speaks only truth, everything He says must be necessarily true. Through the historical inductive method that philochristos mentioned in his opening remarks, we can only conclude that such events are true, but not that they are inspired. How does one conclude that a written medium was, in the mind of God, specially intended for our knowledge? This is how. Tom stranded on an island. He has never heard of God and His Son. He finds a book, starting with the documents of Genesis ending with Revelation. He reads about the accounts of Jesus, about how he built his church upon one man, Peter, and how he told them that he would always be with them, and how the Holy Spirit would lead them into all truth. After some research he concludes the following propositions to be true: Jesus existed, Jesus died, Jesus resurrected, Jesus is God, and the teachings of the apostles preserved these truths (did Jesus ever say, "Write this down..."?), he is a sinner, he trusts in Jesus, etc. Then, a ship comes and sees the stranded man and returns to him to mainland. Say, Italy. He finds a Church, I dunno, in Rome, and exclaims, "Hey! You guys are believers too! Cool! Where are the apostles?" And they say, "We'll, Tom, we have the marks of the Church. We have successors going back to Peter, and we have this history..." The Church then tells Tom, "Hey, so, we're glad you found us and all, but you know that book that you're carrying around, with all those historical documents? Yeah that's actually God's book. So, we exercise our authority to declare this to be true." Philochristos wants to say that I'm in the same epistemic boat as he is. False. It goes: true documents->infallible Jesus->infallible church->infallible documents. We do not assume inspiration of scripture to begin with, but the much more modest claim that is it simply true. This avoids the charge of circularity. So, an authoritative Church is the only epistemically sound foundation for justifying the inspiration of Scripture, and authoritative teachings are necessary for knowing Scripture.