Nevertheless, sacred doctrine makes use of these authorities [i.e., philosophers who are able to know the truth by natural reason] as extrinsic and probable arguments; but properly uses the authority of the canonical Scriptures as an incontrovertible proof, and the authority of the doctors of the Church as one that may properly be used, yet merely as probable. For our faith rests upon the revelation made to the apostles and prophets who wrote the canonical books, and not on the revelations (if any such there are) made to other doctors. Hence Augustine says (Epis. ad Hieron.)1: “Only those books of Scripture which are called canonical have I learned to hold in such honor as to believe their authors have not erred in any way in writing them. But other authors I so read as not to deem everything in their works to be true, merely on account of their having so thought and written, whatever may have been their holiness and learning.”
[Thomas Aquinas (c. 1225-1274), Summa Theologica, First Part, Treatise on God, Question 1, “The Nature and Extent of Sacred Doctrine,” Article 8, “Whether Sacred Doctrine is a Matter of Argument?”, Reply to Objection 2, in Robert Maynard Hutchins, ed., Great Books of the Western World, Volume 19, (Chicago, IL, USA: Encyclopædia Britannica, Inc., 1988), 8.]
ˆ 1There is a discrepancy in my sources for the precise reference of Epis. ad Hieron. (abbreviated Latin for “Epistle to Jerome”). The texts provided by both the Encylopædia Britannica and the Christian Classics Ethereal Library (to which the above bibliographic reference is linked) are based on the translation of the Summa by the Fathers of the English Dominican Province. Britannica’s revision (by Daniel J. Sullivan), however, has properly corrected the reference from Augustine’s 19th (xix) letter (which was not written to Jerome but to Gaius) to his 82nd (lxxxii). Cf. “Letters of St. Augustin,” translated by J.G. Cunningham, in Philip Schaff, ed., Nicene and Post-Nicene Fathers, First Series, Volume 1, (Peabody, MA, USA: Hendrickson Publishers, Inc., reprinted 2004), 350. ˆ
Our Life Is But a Span 
Bryan,
You wrote:
You are distorting my clear meaning, which is easily ascertainable from the context of what I wrote. Far from defining “biblicism” as “merely” an attitude, I described the practical theological outcome of that attitude in my next two sentences (which you ignored):
We give the church councils great weight in our interpretive decisions, but we do not hold them to be infallible. You wrote:
You honestly believe that? So, people can rebel against God while maintaining “a good and respectful attitude” toward Him? How does that work?
I think you’re simply trying to find grounds to justify the harshest possible description of the position you oppose.
You wrote:
And, of course, you have thus far failed to actually demonstrate that Reformation Christians actually make themselves the ultimate interpretive authorities of Scripture. You have simply repeatedly asserted it.
You seem to be assuming here that there are only two possible options: either bow to the ultimate authority of the Roman Catholic church to interpret Scripture, or make one’s self that ultimate authority. I doubt Eastern Orthodox Christians would be impressed. But in light of what the church fathers and medieval doctors have themselves written about Scripture, this position is ludicrous. The Protestant Reformers did not invent sola Scriptura. Augustine affirmed it when he wrote to Jerome:
Cyril of Jerusalem affirmed it when he wrote:
And Thomas Aquinas affirms sola Scriptura when he quotes Augustine:
It seems from these citations that the Protestant doctrine of the perspicacity of Scripture is part of the heritage of the early and medieval church. Not only did Augustine, Cyril, Aquinas and others bow to the authority of Scripture above all else, but they also affirmed that Scripture is clear enough to be understood without another authority, especially a highly coercive one like the medieval church, forcing its interpretations on the reader.
You wrote:
Your complaint about Reformation Christians rejecting “the Church’s councils” is a red herring. The only church council to which we uniformly take major exception is the one that was specifically designed by the papacy to be impossible for us to accept: the Council of Trent.