I agree that the authority of our teachers / fathers / brothers in the church is derived from authority, and (thus) inferior to it. And what happens when those teachers / fathers / brothers disagree? They appeal to Scripture, make their arguments from Scripture. Yes, sadly, there are those who misinterpret the Scriptures - whether from ignorance or malice - and Paul warned us of them in Acts 20.

That derived authority is not vested in individuals or even offices directly--but to the whole church, as a church. And then men are chosen to fill those offices--but they can be removed for unfaithfulness. But there's only one "kind" of authority in the church.

And, when I say that the Scriptures interpret themselves, what I mean is that we can interpret the more difficult passages by the more clear passages, and follow what comes out "by good and necessary consequence." I also mean that the Scriptures are _sufficient_ for teaching us "all things necessary for life and godliness," etc.