Jason Engwer continues whining.
His argument consists entirely of two points:
1. Apologetics ought to be based on "publicly verifiable" theological principles.
2. The GHM is "publicly verifiable."
Regarding (1), this is entirely based on his own peculiar standards for "publicly verifiable." Plenty of people agree with the apostolic succession being "publicly verifiable," as it is a matter of historical record that ecumenical councils were used to resolve theological disputes. Plenty of people reject the notion that the GHM is a limiting criterion on ascertaining apostolic theology (e.g., they accept natural theology, conciliar declarations, papal pronouncements, etc., as evidence of apostolic doctrine). So I simply reject his idiosyncratic criteria for public verifiability as meaningful or binding on anyone, and I think his demands that I provide evidence of "public verifiability" of the apostolic succession are ridiculous, as I have provided evidence that plenty of people would consider adequate for public verifiability. The fact my arguments aren't what Jason considers "publicly verifiable" means nothing unless Jason can prove that a reasonable person must meet his standard for public verifiability. So yes, the fact that earlier sources are more accurate at describing meaning of a text, for example, is not a publicly shared premise, because it asserts the GHM as a limiting criterion on ascertaining apostolic theology. This is exactly what I mean by the astrological method; it's not a commonly shared premise that the GHM is a limit on ascertaining apostolic theology, so it's an idiosyncratic use of a commonly-accepted method to use the GHM in this way.
Regarding (2), Jason has characterized my objection to his method as that it provides "insufficient certainty." This is only tangentially related to my objection. The point is that it has insufficient objective certainty to justify Jason's stance that only what is "ascertainable" is binding. What is "ascertainable" by the GHM is more or less bare possibility; beyond that, it is a subjective question as to what is "probable," "likely," and whatnot. Moreover, that determination also implicitly includes a determination on what counts as evidence for particular interpretations, and Jason's use of the GHM as a limiting factor excludes evidence that many people consider persuasive for meaning. My point is that he is imposing subjective, not objective, criteria as a binding limit on theological speculation, and that is unwarranted.
Regarding Scholarship 101, there are some very simple concepts I have in mind:
1. Evidence is cited for arguments, not conclusions. The corollary is that citing someone as evidence means that you agree with their conclusions and their reasons for the conclusions.
2. This means that if you don't know a person's reasons for a conclusion, you can't cite that person as evidence. Period. Full stop. If they don't say and you don't have any way to figure it out, you don't cite them unless you intend to make yourself a liar. You can't assume they agree with you; you have to verify it, because you are signing your name to the statement that the author agrees with your reasons.
3. Contrary to Jason's assertion, I never cite a source without a reasonable basis for thinking that I know why they are making the statement (if it's an older source, that always means that I have a qualified secondary source backing up my interpretation), and I never cite a source whose reasons for a conclusion contradict my own. If I do, please call me on it; it's culpable negligence.
4. With respect to Jason's particular situation, he has difficulty as a free-churcher because his view entails two assertions: first, justification by faith alone entails that baptismal regeneration is false, and second, that Scripture clearly and definitively teaches that baptismal regeneration is false and even anathematizes the belief. So when he cites an author for JBFA who also believes in some form of baptismal regeneration (as significant numbers of Lutherans, Anglicans, Presbyterians, the Magisterial Reformers, and virtually all the church fathers do), then he has a problem. He can argue that they are so wildly inconsistent in Biblical interpretation that they missed a clear and definitive teaching of Scripture but managed to get JBFA correct in his mind, which makes them a poor witness for whatever they do testify, assuming that they are being cited as witnesses for correct interpretation. Alternatively, he can argue that they teach his understanding of JBFA, which would simply be lying, as their reasons for thinking Paul teaches JBFA contradict Jason's own. Consequently, I can't fathom how credobaptists could ever credibly cite paedobaptists as evidence for their position on justification or vice versa, because they have contradictory reasons for believing what they believe about justification. Whether it's within the scope of "permissible differences" or not is irrelevant; the fact is that they are two mutually contradictory rationales for the conclusion.
So Jason can whine about his mistreatment at my hands as long as he likes, but whining will not persuade me that his arguments have more force than they do, and I'm sure it won't persuade anyone else either.