The doctrine of sola scriptura is not one that I thought much about in my Protestant days. It was a given. It was never expounded or explained. Usually it was just expected to be held. I simply adopted the mindset that what was in the Bible was good enough for generations of people to surround themselves with. They could have good fellowship and learn from our love letter from God. I never questioned this doctrine nor did I understand the implications of it. That changed upon reading an essay by Jimmy Akin that challenged not the biblical basis of it but the practical problems associated with it. Without reprinting the whole of the text (available online here), I will summarize the points that most resonated with me:

1. Private interpretation is a necessary corollary of sola scriptura.
2. Most people do not have the time required to become Scripture scholars.
3. History shows that most people were illiterate thus if Bible reading were THAT important, Christians historically would have placed a high priority on literacy.
4. But that wasn't necessary because the printing press was not invented until the 15th century, thus access to books was very limited not because the Church kept the scriptures from the people but because it costs several years wages to get your hands on a Bible.

Thus, historically speaking, heading to church with a Bible in tow to hear a preacher expound upon the Word is a recent historical innovation. It simply was not possible until mass production processes made books affordable and available to the masses. Beyond that the typical arguments against the Church regarding the Bible were almost easily explainable as I soon learned by reading Catholic/Protestant debates on the matter.

Charge: The Church prohibited translations and kept the Scriptures from the people.
Response:: In some cases, this is true but the reason was to safeguard the accurate meaning of the Scriptures. This phenomenon was largely limited to England.

Charge: The Church chained down Bibles because they didn't want people to have them.
Response:: Bibles were valuable. They were typically available for people to read but the reality is that most people could not read.

Charge: The Church added books to the Bible. You can see this by their affirming the Canon containing these books after the time of Luther.
Response:: The Gutenberg Bible, a Catholic Bible, contained the Deuterocanon (see Reminder that the Deuterocanon is in the Gutenberg Bible). Numerous references the deuterocanonical books can be found throughout the historical documents of the Church (Early Church Fathers: Old Testament Canon). Earlier local councils (Council of Rome in 382 and the Council of Hippo in 393) affirmed the Deuterocanon which was not in dispute until the time of the reformation.

Charge: Catholics were ignorant of the Scriptures until the reformation
Response: It is historically verifiable that Catholics were taught about the Bible before the reformation. The documents of the early church fathers are strewn with Bible verses and commentary which rivals that of the best preachers today. Books written by the saints further underscore this point. You can find excellent Bible commentary from just about every century of the Church. Furthermore, one only needs to look at the stained glass windows of Sainte Chapelle in France to realize that pre-reformation Christians were not ignorant of Scripture. The entire collection of images in the building is a history of the Church (with some French embellishment towards the end) ... Most of your Bible stories are contained. A cursory review of art history, especially western art in the time frame just prior to the reformation includes numerous examples of Bible events, especially those in the New Testament.

Another key point that really hit home with me is that none of the defenses that Catholics use against Protestant attacks on their understanding of the Bible are new. From St. Thomas Aquinas back to the time of St. Clement of Rome, writings can be found that defend certain Catholic doctrines in the same manner they are defended today by Jimmy Akin, Dave Armstrong, Mark Shea and others. St. Francis de Sales was not treading much new ground when he wrote his defenses of the Church against the reformers.

Finally, the doctrine of sola scriptura is foreign to Scripture. That would make it, as is often charged of Catholics, a tradition of men.

The passage most commonly brought up by Evangelicals and Fundamentalists is 2 Timothy 3:16–17. In the King James Version, the verse reads this way: "All Scripture is given by inspiration of God and is profitable for doctrine, for reproof, for correction, for instruction in righteous- ness; That the man of God may be perfect, thoroughly furnished unto all good works."

Many claim that 2 Timothy 3:16–17 claims Scripture is sufficient as a rule of faith. But an examination of the verse in context shows that it doesn’t claim that at all; it only claims Scripture is "profitable" (Greek: ophelimos) that is, helpful. Many things can be profitable for moving one toward a goal, without being sufficient in getting one to the goal. Notice that the passage nowhere even hints that Scripture is "sufficient"—which is, of course, exactly what Protestants think the passage means.

Point out that the context of 2 Timothy 3:16–17 is Paul laying down a guideline for Timothy to make use of Scripture and tradition in his ministry as a bishop. Paul says, "But continue thou in the things which thou hast learned and hast been assured of, knowing of whom thou hast learned them; and that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus. All Scripture is given by inspiration of God (Greek: theopneustos = "God-breathed"), and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, thoroughly furnished unto all good works" (2 Tim. 3:14–17). In verse 14, Timothy is initially exhorted to hold to the oral teachings—the traditions—that he received from the apostle Paul. This echoes Paul’s reminder of the value of oral tradition in 1:13–14, "Follow the pattern of the sound words which you have heard from me, in the faith and love which are in Christ Jesus; guard the truth that has been entrusted to you by the Holy Spirit who dwells within us" (RSV), and ". . . what you have heard from me before many witnesses entrust to faithful men who will be able to teach others also" (2:2). Here Paul refers exclusively to oral teaching and reminds Timothy to follow that as the "pattern" for his own teaching (1:13). Only after this is Scripture mentioned as "profitable" for Timothy’s ministry.

The few other verses that might be brought up to "prove" the sufficiency of Scripture can be handled the same way. Not one uses the word "sufficient"—each one implies profitability or usefulness, and many are given at the same time as an exhortation to hold fast to the oral teaching of our Lord and the apostles. The thing to keep in mind is that nowhere does the Bible say, "Scripture alone is sufficient," and nowhere does the Bible imply it. Catholic Answers: What's Your Authority?

A crisis of faith

This caused a radical shattering of some presumptions I had. Without an authority, the Scriptures alone were not sufficient to logically support themselves. After all, why would I trust them over any other book that someone hands me and says "THIS is the inspired Word of God". One of two solutions seemed possible and they were both uncomfortable. The first was to find myself outside the Christian faith. I could not understand how God would have allowed his faith to wander aimlessly for 3-4 centuries without something so critical as the Bible itself. The Canon of the New Testament is first documented by St. Athanasius (who further believed in the Primacy of the Roman Church, the Real Presence of Christ in the Eucharist, Apostolic Tradition). I thought long and hard about this. Over time I came to the conclusion that I had seen too much of what God had done in my life to ignore it. The other solution was to review the path of the apostolic churches, the ones that had continuity with history and championed some role of having guarded the deposit of the faith since the time of Christ.

So what of the role of of the Church, in other words, tradition? St. Basil the Great (c. 330-c. 379) puts it best

The Church preserves many beliefs and practices that generally are accepted or publicly commanded. Some are taken from written teaching; others have been passed on to us “in a mystery” by the tradition of the apostles. In relation to true religion, both of these have the same force.

I had to find out more.