I intend to continue the series on the fathers on the Church. But I was prompted to write this after reading the ongoing discussion over at De Regnis Duobus.
To place one's own interpretation of Scripture above that of all the bishops in plenary council is performatively to deny that Christ established any enduring teaching office or teaching authority in the Church. For such a person, the only remaining 'teaching authority' possible is by definition that of "those who agree with me and my interpretation". And that is no authority at all, but only a self-deceiving pretense at being under authority, as St. Paul describes in 2 Timothy 4:3. Such a person may give lip-service to the notion of 'secondary' authority, but in principle his position is still individualistic, because the authority of the 'secondary authority' always remains subject to the individual's own approval and agreement.
Individualism always leads to fragmentation and disintegration (i.e. loss of unity), for agere sequitur esse, i.e. a thing acts according to what it is, and there is no being where there is no unity. But Christ set up His Church to endure (i.e. remain in being) until He returns, and therefore He did not leave it without an enduring teaching authority. And therefore it follows that the individual and his own interpretation of Scripture are subject to the teaching authority of the bishops in plenary council.
To accept the teaching authority of the Church for the determination of the canon of Scripture, while rejecting the teaching authority of the Church for the interpretation of Scripture, is a deep tension internal to all Protestant ecclesiologies. Either the determination of the canon is subject to each individual, or the determination of the interpretation of Scripture is subject to the teaching authority of the Church. Anything else is ad hoc.
The Protestant reply is to appeal to the perspicuity of Scripture, meaning that the nature of the gospel as recorded in Scripture is self-evident to any competent reader. So there doesn't need to be any "teaching authority", because any competent reader can determine for himself from Scripture what is the nature of the gospel. Any competent reader can therefore go against all the bishops in plenary council (or any other group of persons for that matter) when that reader determines for himself that what they are teaching is contrary to what is self-evident from Scripture concerning the gospel. But which is more self-evident from the available evidence: that the nature of the gospel is self-evident to any competent reader, or that over the course of Church history, many competent readers have deeply disagreed with each other about the nature of the gospel to the point of schism and even violence? The claim that the nature of the gospel is self-evident to any competent reader is a presupposition that is imported (by Protestants) to the interpretive process. It is not derived from Scripture. (Even the attempt to derive the notion of perspicuity from Scripture in a certain sense presupposes it.) It has its origin not in the fathers, but with the invention of the printing press and the surge of confidence in the power of human reason accompanying Renaissance humanism. It assumes that the nature of the gospel as recorded in Scripture is such that no competent reader will come to a determination about it that is contrary to one's own, all other things being equal. It assumes that the effort that was necessary for a Protestant to come to his present determination of the nature of the gospel is all the effort necessary for him to have understood fully and truly what is the nature of the gospel.
If this claim [i.e. that the nature of the gospel is self-evident to any competent reader] is false, then the person claiming to have derived it from Scripture is deeply mistaken, not only by importing a false presupposition to the interpretive process, but also in falsely deriving that false presupposition from Scripture. But the claim is not only a presupposition; it is also an empirical claim that is in principle falsifiable. So, if history has not falsified it, what would history have to look like in order to falsify it? How much more divided over the nature of the gospel would Christians have to be (and have been) before the perspicuity claim would be falsified?
"Let unity, the greatest good of all goods, be your preoccupation." - St. Ignatius of Antioch (Letter to St. Polycarp)