Hi Geoff,

Let me see if I can assist you with some counter arguments.

First of all, we have to explode the myth that all that is required to establish orthodox doctrine,
is to argue and correctly interpret the Scriptures; that as long as your doctrine is "Bible-based", you cannot fall into error.

With only a few exceptions, nearly all of the major heresies in the Church — both those commonly accepted among all Christians as heresies, such as Arianism, as well as those judged heresies primarily by the Catholic Church — made their arguments from Scripture. The disputes lay over interpretation, but not all interpretations are authentic.  Furthermore, the refutations which the Fathers used were not always from Scripture.  Often the refutations were from Scripture, but
at other times, they refuted their opponents by referencing the living Tradition of the Church. Hence, the Sacred Scriptures cannot be divorced from the one to whom the Faith was entrusted (cf. Jude 3), that is, the "Church of the living God, which is the pillar and foundation of the truth" (1 Timothy 3:15).

Indeed, an early saint, St. Papias of the first century, Bishop of Hierapolis, a disciple of John and friend of Polycarp, held an intense distrust in the written word, knowing that it was unable to arbitrate disputes or explain itself in the case of divergent opinions on interpretation. Nor can the written word answer questions, he argued. He diligently inquired of the surviving voices of the Apostles, including St. John and the disciples of other Apostles. He said,

"I simply took for granted that book knowledge would not help me so much as a living or still surviving voice."

St. Irenaeus, disciple of Polycarp, makes this argument, that Tradition is necessary to resolve the disputes that arise (Against Heresies, 3, 4, 1, 180 A.D.):

"When, therefore, we have such proofs, it is not necessary to seek among others the truth which is easily obtained from the Church. For the Apostles, like a rich man in a bank, deposited with her most copiously everything which pertains to the truth; and everyone whosoever wishes draws from her the drink of life. For she is the entrance to life, while all the rest are thieves and robbers [cf. John 10:1-10]. That is why it is surely necessary to avoid [heretics], while cherishing with the utmost diligence the things pertaining to the Church, and to lay hold of the tradition of truth.

• What then?
• If there should be a dispute over some kind of question, ought we not have recourse to the most ancient Churches in which the Apostles were familiar, and draw from them what is clear and certain in regard to that question?
• What if the Apostles had not in fact left writings to us?
• Would it not be necessary to follow the order of tradition, which was handed down to those to whom they entrusted the churches?"

Tertullian makes a similar point (Tertullian, The Fundamental Doctrines, 220-230 A.D.,
1, Preface, 2):

"Although there are many who believe that they themselves hold to the teachings of Christ, there are yet some among them who think differently from their predecessors. The teaching of the Church has indeed been handed down through an order of succession from the Apostles, and remains in the Churches even to the present time. That alone is to be believed as the truth which is in no way at variance with ecclesiastical and apostolic tradition."

Tertullian notes elsewhere that while the Scriptures are Truth, we have not only received them, but also their proper interpretation (De praescriptione haereticorum, A.D. 200, 19,3):

"Wherever it shall be clear that the truth of the Christian discipline and faith are present, there also will be found the truth of the Scriptures and of their explanation, and of all the Christian traditions."

St. Irenaeus echoes Tertullian's point that Divine Revelation encompasses both Scripture and Tradition (Against Heresies, 4, 33, 8):

"The true gnosis [knowledge] is the doctrine of the Apostles, and the ancient organization of the Church throughout the whole world, and the manifestation of the body of Christ according to the successions of bishops, by which successions the bishops have handed down the Church which is found everywhere; and the very complete tradition of the Scriptures, which have come down to us by being guarded against falsification, and which are received without addition or deletion; and reading without falsification, and a legitimate and diligent exposition according to the Scriptures, without danger and without blasphemy; and the pre-eminent gift of love, which is more precious than knowledge, more glorious than prophecy, and more honored than all the other charismatic gifts."

Thus, the early Christians placed a strong emphasis on obeying Tradition. St. Irenaeus again says (Against Heresies, 1, 10, 1-2):

"For the Church, although dispersed throughout the whole world even to the ends of the earth, has received from the Apostles and from their disciples the faith in one God. . .

"The Church, having received this preaching and this faith, although she is disseminated throughout the whole world, yet is guarded, as if she occupies but one house. . . She, harmoniously, proclaims [the truth] and teaches it and hands it down as if she possessed the one mouth. For, while the languages of the world are diverse, nevertheless, the authority of the tradition is one and the same. . .

"Nor will any of the rulers in the churches, whatever his power of eloquence, teach otherwise, for no one is above the teacher; nor will he who is weak in speaking detract from the tradition."

Elsewhere, after explaining the importance of the Sacred Scriptures, he nonetheless adds,

"It is possible, then, for everyone in every [local] church who may wish to know the truth, to contemplate the tradition of the Apostles which has been made known throughout the whole world. . . We are in a position to enumerate those who were instituted bishops by the Apostles, and their successors to our own times: men. . . to whom they were committing the self-same churches. . . They wished all those and their successors to be perfect and without reproach, to whom they handed their authority." (Against Heresies 3, 3, 1)

Perhaps the most complete and cogent argument comes a bit later in the Church, but nonetheless, if I did not give you the date beforehand, you certainly would not have guessed that it was not addressing Protestants but those about a thousand years earlier:

St. Vincent of Lerins, Commonitoria [2, 1-3], circa 434 A.D., quoted from The Faith of the Early Fathers, 2168:

With great zeal and closest attention, therefore, I frequently inquired of many men, eminent for their holiness and doctrine, how I might, in a concise and, so to speak, general and ordinary way, distinguish the truth of the Catholic faith from the falsehood of heretical depravity. I received almost always the same answer from all of them, that if I or anyone else wanted to expose the frauds and escape the snares of the heretics who rise up, and to remain intact and sound in a sound faith, it would be necessary, with the help of the Lord, to fortify that faith in a twofold manner: first, of course, by the authority of the divine law; and then, by the Tradition of the Catholic Church.

Here, perhaps, someone may ask: "If the canon of the Scriptures be perfect, and in itself more than suffices for everything, why is it necessary that the authority of ecclesiastical interpretation be joined to it?" Because, quite plainly, Sacred Scripture, by reason of its own depth, is not accepted by everyone as having one and the same meaning. The same passage is interpreted in one way by some, in another by others, so that it can almost appear as if there are as many opinions as there are men. Novatian explains a passage in one way, Sabellius in another, Donatus in another; Arius, Eunomius, Macedonius in another; Photinus, Apollinaris, Priscillian in another; Jovinian, Pelagius, Caelestius in another; and afterwards in still another, Nestorius. And thus, because of so many distortions of such various errors, it is highly necessary that the line of prophetic and apostolic interpretation be directed in accord with the norm of the ecclesiastical and Catholic meaning.

In the Catholic Church herself every care must be taken that we may hold fast to that which has been believed everywhere, always, and by all. For this is, then, truly and properly Catholic. That is what the force and meaning of the name itself declares, a name that embraces all almost universally. This general rule will be correctly applied if we pursue universality, antiquity, and agreement. And we follow universality in this way, if we confess this one faith to be true, which is confessed by the whole Church throughout the whole world; antiquity, however, if we in no way depart from those interpretations which, it is clear, our holy predecessors and fathers solemnized; and likewise agreement, if, in this very antiquity, we adopt the definitions and theses of all or certainly of almost all priests and teachers.

Ecclesiastes says, "There is nothing new under the sun" (1:9), and, indeed, I find the best, most splendid defenses against present day objections can be found from our venerable Fathers thousands of years ago. I could provide many more quotes — it is not as if I lack them —
but I think that these are a start.

The point that St. Vincent makes also proves an excellent explanation of what we as Catholics believe to be true, that is, precisely those things which have always and everywhere been believed by the Church. In other words, neither Council nor Pope proposes new or unusual doctrines as infallible teaching; they can only proclaim as infallible those teachings which are contained in the Deposit of Faith left to us by the Apostles. For a doctrine to be agreed upon "always and everywhere" by the Church, is no mean feat when you consider a world with no electronic communication, but which rapidly stretched all over the world. Indeed, for Protestants, such a constant agreement may seem unbelievable and unattainable, and yet it has existed and does exist in the Catholic Church. Even churches which separated from the Catholic Church in the remotest parts of the world in the earliest times — for example, non-Chalcedonian churches in India separated since the 5th century — you will find a faith which differs very little from our own. I believe that the doctrinal unity, within cultural and liturgical diversity in all of the Church throughout the world, and throughout the ages, is a powerful and compelling witness to the faithfulness and Truth of the Catholic Faith.

During my conversion to the Catholic Faith (I say "conversion" because I never fully accepted it in the first place), a significant milestone was reached when I realized that Tradition is not opposed to Scripture. Its importance is not so much to enhance Scripture, as if Scripture were insufficient or deficient, but its importance lies in helping us to "rightly divide the Word of truth" and discern true interpretation from false. I realized, most importantly, that far from adding a heavy weight of accretions to Christian doctrine, Tradition rather keeps the Faith pure by stripping away myriads of conflicting interpretations of Scripture, keeping Christian doctrine clear, precise and well-defined. Without Tradition, you have a kind of "probability distribution" of possible interpretations of various Scriptures, interpretations which vary over a wide range, from one side of the spectrum to another. But with Holy Tradition, we are not doomed to argue endlessly, never knowing for sure what the Sacred authors really meant when they wrote a particular controversial verse. To base Christian doctrine on Scripture alone is to base it on a foundation of shifting sand, not because Scripture is imperfect, but because our interpretation — apart from the Church of Christ — will always be fallible and subject to every wind and wave of doctrine.

Looking at all the diverse groups who claimed "Biblical teaching", I saw that the issue was not whether you followed tradition or not, but whose tradition you followed, because, like it or not, every one of us is influenced by tradition: this is inescapable. It colors our vision. We read the Bible in the light of the interpretation of those who have taught us, and of those whose arguments we've read. The key is to find the true Tradition. It is said that we are never in so much danger of being deluded by Satan, as when we are convinced that he poses no danger. Similarly, you are never so much in danger of succumbing to the traditions of men as when you are convinced that you are not in such a danger, because you follow the "Bible alone."

Sola Scriptura is fundamentally individualistic and experiential. One assumes that the Holy Spirit will guide him into the right interpretation of Scripture, which is not an unreasonable assumption. However, if true, it means that when you disagree with another's "Spirit-led" interpretation, since obviously you know you've been seeking the Holy Spirit, and so He's been guiding you to the right interpretation, the other person must necessarily be deceived. The end result is the individual becomes the supreme arbiter of the Holy Scriptures, against every other individual, because obviously, the only person you can know for sure really believes and really seeks the Holy Spirit is yourself. All doctrines then are judged against your own "canon" (measuring-rod).

The Catholic view is a bit more humble. One's interpretation of Scripture is submitted to that interpretation which the whole Church everywhere has always understood, and those interpretations which the leaders of the Church, the successors to the Apostles, have discerned, gathered in Council, praying and seeking the Holy Spirit, according to the pattern laid down by Sacred Scripture in Acts 15.

Let us consider where a rejection of Tradition ultimately leads us. The opposition of something which is "traditional", is something which is a novelty or innovation. Thus, a rejection of tradition necessitates renouncing what one has been taught in favor of different, newer ideas — new interpretations of Scripture, new and untried practices — for the longer one believes what one has been taught, the more "traditional" one is. Not only is this antithetical to belief in absolute, unchanging Truth, given to us "once for all" by the Apostles, it introduces instability. It requires changing one's doctrine in order to avoid being "traditional". Ultimately this destroys the Church. Since the Faith was "once for all delivered to the saints" (Jude 3), novelty and innovation
(of the fundamentals) are excluded, and Holy Tradition is the canon by which interpretation of Scripture must be measured by.

Finally, let's turn to the Scriptures and see what they say. Paul praised the Corinthians for obeying the Tradition they received (1 Corinthians 11:2). Clearly then, there is good tradition, and there is bad tradition. We may be obliged to reject the "traditions of men", but there are also the traditions of God, to which we must adhere. It is to the saints that the Faith has been entrusted (Jude 3). This implies a living deposit — one not merely written on paper, but written also in the hearts of believers. The foundation of the Church is on the Apostles and prophets (Ephesians 2:20). Again, it is founded more on people, than on a dead letter.

"Hold fast to the traditions which you received, whether by word of mouth or by letter" (2 Thessalonians 2:15).

Here St. Paul articulates the principle that the Word of God has two components: oral and written. He goes so far as to call Sacred Scripture a tradition.

"Keep away from every brother who does not live according to the teaching you received from us." (2 Thessalonians 3:6)

Again, this has an oral sense about it — "received" calls to mind the "paradosis", or handing on of Tradition. You would have expected him, if Sola Scriptura were true, to say to keep away from those who do not follow the Scriptures.

"And we also thank God continually because, when you received the word of God, which you heard from us, you accepted it not as the word of men, but as it actually is, the word of God, which is at work in you who believe." (1 Thessalonians 2:13)

Here again, more explicitly this time, the Word of God is something that is oral — you hear it from the Apostles, you don't (merely) read it in a book. The Word of God comes from the mouth of the Apostles, not only from Scripture.

"What you have heard from me, keep as the pattern of sound teaching, with faith and love in Christ Jesus. Guard the good deposit that was entrusted to you — guard it with the help of the Holy Spirit who lives in us." (2 Timothy 1:13f)

Here again we have the concept of the Deposit of Faith kept in the hearts of believers, a tradition to be handed down.

"It would have been better for them not to have known the way of righteousness, than to have known it and then to turn their backs on the sacred command that was passed on to them." (2 Peter 2:21)

Again — the language of tradition: "that was passed on to them."

"The grass withers and the flowers fail, but the word of the Lord stands forever. And this is the word that was preached to you." (1 Peter 1:25)

The Word of God is oral. Again, if Peter were an Evangelical, you'd expect him to associate this with the Bible, but he doesn't.

"'The Redeemer will come to Zion, to those in Jacob who repent of their sins,' declares the Lord. `As for me, this is my covenant with them,' says the Lord.
`My Spirit, which is on you, and my words that I have put in your mouth will not depart from your mouth, or from the mouths of your children, or from the mouths of their descendants from this time on and forever,' says the Lord."
(Isaiah 59:20-21)

This is interesting, as it suggests that God will, in the New Covenant, preserve his Teaching in the mouths of believers forever, which is exactly what we believe about Sacred Tradition.

"His letters contain some things which are hard to understand, which ignorant and unstable people distort, as they do the other Scriptures, to their own destruction.
(2 Peter 3:16)

This demonstrates that it is possible to misinterpret Scriptures badly enough so as to lose one's salvation — which means that Scriptures themselves are insufficient; you need the right interpretation of Scripture to go along with them, and that is the role of Sacred Tradition.

"How, then, can they call on the one they have not believed in? And how can they believe in the one of whom they have not heard? And how can they hear without someone preaching to them? And how can they preach unless they are sent? As it is written, `How beautiful are the feet of those who bring good news!' But not all the Israelites accepted the good news. For Isaiah says, `Lord, who has believed our message?' Consequently, faith comes from hearing the message, and the message is heard through the word of Christ. But I ask: Did they not hear? Of course they did: `Their voice has gone out into all the earth, their words to the end of the world.'" (Romans 10:14-18)

These are other verses underscoring the oral nature of the proclamation of the Gospel: It's not "Go and read the Scriptures and believe", it is,

"Listen to the message proclaimed by the ministers of God". "But when he, the Spirit of Truth, comes, he will guide you into all truth" (John 16:13)

"But the Counselor, the Holy Spirit, whom the Father will send in my name, will teach you all things and will remind you of everything I have said to you" (John 14:26)

These two verses highlight the role of the Spirit, who will, it says, guide the Church into all Truth and remind Her of all that Jesus taught.

This is a task done by the Spirit, not by the Scriptures, for the Scriptures are limited in what they can teach, specifically because they are subject to vagaries of interpretation. You need something that can settle disputes over what Scripture teaches, and that's the Holy Spirit working through the bishops in union with the Pope.

"But you, remain faithful to what you have learned and believed, because you know from whom you learned it, and that from infancy you have known [the] sacred scriptures." (2 Timothy 3:14-15).

Here, Timothy is exhorted in two ways: Yes, to know the Sacred Scriptures (please don't think
I am minimizing the importance of that), but also to believe what he has learned because he knows from whom he learned it — Apostolic sources. In other words, he is to rely on the
testimony of who taught him on the basis of who they were, Apostolic teachers.

"[An elder] must hold firmly to the trustworthy message as it has been taught, so that he can encourage others by sound doctrine and refute those who oppose it." (Titus 1:9)

Here, Titus is being encouraged to cling to what he has been taught — again departing from the "Read and follow the Scriptures yourself" model in favor of an Apostolic model.

"The teachers of the law and the Pharisees sit in Moses' seat. So you must obey them and do everything they tell you. But do not do what they do, for they do not practice what they preach." (Matthew 23:2-3)

I like this verse for a couple of reasons.

1. One is because Jesus is binding His followers to an unwritten Jewish tradition, that is, that there was a seat of Moses that made final decisions about matters of doctrine, an office handed down from Moses' time. So Jesus accepted some Jewish traditions and did not reject all of them.
   
   
2. The other reason I like it is that, while Jesus acknowledges the Scribes and the Pharisees are corrupt, He nevertheless commands His disciples to obey them. So this whole Reformation argument of
   
   
   "Well, the Catholic bishops are corrupt, so that justifies our disobedience."
   
   doesn't wash. Then, in Acts 8:31, we have the Ethiopian eunuch, who ably points out that we cannot understand the Scriptures without someone to interpret them for us. They cannot stand alone; we must rely on Tradition to interpret them. Even Protestants do this; they just won't admit it. Along those lines,

"7 The Levites—Jeshua, Bani, Sherebiah, Jamin, Akkub, Shabbethai, Hodiah, Maaseiah, Kelita, Azariah, Jozabad, Hanan and Pelaiah — instructed the people in the Law while the people were standing there. 8 They read from the Book of the Law of God, making it clear and giving the meaning so that the people could understand what was being read."

(Nehemiah 8:7-8)

Another example of how the Scripture needs to be explained by others. So as we can see, there are many verses supporting the idea of Tradition and the Catholic conception of an oral Deposit of Faith.

Hope this helps!

Eric