Bondage of the Will, Part 3, paragraphs 1-3
1. Appealing to the Ancients - Here's a tricky one; your opponent claims that the weight of church history, especially of the church fathers, is squarely on his side. How to respond? In many ways, it appeared that Erasmus had the numbers on his side and then challenged Luther about abandoning the testimony of the ancients. Luther first expresses that his position is not without supporters (most notably Augustine), then that he only departed from the church's historical teaching when prompted by Scripture and conscience.
Luther then reminds his reader that imperfections were present in the fathers just as every other man (even the apostle Peter who spoke so rashly) – some of whom may not have been true believers. Luther proceeds to go on the offensive, drawing Erasmus appeal to the fathers together with his support of freewill. Why not have the church fathers prove freewill by showing evidence of the Spirit apart from grace, by working miracles out of their own will rather than God's, or by progressing in holiness through an exertion of their own might. It has never, and will never, happen. Thus, not only are the fathers not fully authoritative, their very imperfections prove Luther's position that freewill is an illusion.
2. Appealing to the church of history – A similar argument by Erasmus is this: it is simply unbelievable that God would have let this error, if it is an error, to continue so long unchecked. Luther responds that the true (i.e., invisible) church never errs. He supports this with an argument for this theological distinction between the visible church, which includes unregenerate, and the invisible church, composed of only the elect. [Here I think Luther's position is weak – it's hard to support the argument that the invisible church never errs; it's easier to show that God often waits for seemingly lengthy periods of time before correcting His people; indeed, His delay is itself a symbol of mercy.]
Luther shows grace in having charity accept baptism as a true sign of conversion, until otherwise proven. But he's also not naïve enough to believe all the baptized speak with the same authority or understanding. He wisely points out that the church fathers themselves often disagreed; if we are to appeal to those fathers, we have no ultimate standard of discrimination other than Scripture...
3. Appealing to Scripture – Erasmus settles firmly in the “undecided” category because there are learned men on both sides and the Bible “is somewhat deficient in clarity at present.” This is a line of argumentation that would lead one to desire another authoritative voice, namely that of the bishop of Rome. This is how, according to Luther, men have exalted themselves above Scripture, justifying whatever actions seem best to them.
Men's responsibility, however, is to judge, to decide where the truth lies. The first standard of judgment is the inward enlightening of the Holy Spirit, the “internal perspicuity of the Holy Scripture.” The second standard is the external perspicuity of the Scripture, or the clarity of Scripture as taught by honest preachers and teachers of God. For it should be settled as fundamental, and most firmly fixed in the minds of Christians, that the Holy Scriptures are a spiritual light far brighter than the sun, especially in what relates to salvation and all essential matters.
[These points are a great call for us to decide what our standards and ultimate standard will be. What place will the fathers have in helping you decide right and wrong, true and false? What place will Scripture have? Elevating the second is not to trash the first, but to give the first something to aspire to, to have that final, ultimately trustworthy authority that all men ought to crave.]