So much for that hibernation. I've been asked to elaborate on the following quote, most of which I provided in my most recent post (link):
We can ask why self-justifying reasons are self-justifying. If the traditional foundationalist has an answer, it seems like it must involve some metajustificatory feature. If the traditional foundationalist has no answer, it seems like the view has arbitrary foundations. (See BonJour, Structure, 30-3, for a similar argument.)
However, the traditional foundationalist can argue that completely self-justifying reasons are not self-justifying in virtue of some metajustificatory feature, nor are they arbitrary. It may be that certain reasons have to be assumed to be self-justifying if skepticism is to be avoided. This is a rather familiar form of rationalist argument for the existence of a priori justification. Here, the main implication of these arguments is that there might be a way to non arbitrarily show that we need to take certain reasons to be completely self-justifying without requiring that there be a metajustificatory feature which makes those reasons self-justifying. What convinces us we need to take those reasons to be self-justifying need not make them self-justifying.
This move does not seem to be available in the case of reasons that are self-justifying only to a degree. (pg. 544)
Fantl draws a distinction between two types of foundationalism: traditional and metajustificatory. In both cases, what is under consideration is the justificatory status of basic beliefs, foundations, first principles, epistemic presuppositions, axioms, [insert favorite synonym here]. On traditional foundationalism, a basic belief is self-justifying; that is, one is justified in believing a proposition just because the proposition is true. On metajustificatory foundationalism, a basic belief is justified because of some feature the proposition in question possesses in addition to its own propositional content: its feature could refer to coherence, reliable deliverance, or whatnot. See pg. 540ff. for particulars.
Klein thinks a metajustification is a justification of a belief, "justifications designed to show that certain types of beliefs are acceptable even in the absence of another belief that serves as a reason... because they have some property, call it P, and beliefs having P are likely to be true" ("Human Knowledge and the Infinite Regress of Reasons," pg. 303; link). Note the word "likely." I'm not sure that metajustificatory foundationalism is committed to fallibilism, and Klein may have a different view of what metajustification is than Fantl, but given that Fantl thinks that metajustificatory foundationalism can satisfy the so-called "degree requirement," it's worth mentioning that metajustificatory foundationalism would be compatible with a fallible foundational belief.
Traditional foundationalism, on the other hand, is not compatible with fallibilism. For as Fantl notes, the question would otherwise arise as to why certain basic beliefs would be justified to a degree different than that of other basic beliefs. An answer can't fall back on a metajustificatory feature by definition (traditional vs. metajustificatory), nor does it make sense to ground the difference on a common quality, viz. that both propositions in question are true. So arbitrariness would seem to appear here. Hence we have Fantl's implication in the above quote that traditional foundationalism must take the only out given to it: deny fallibilism, i.e. the "degree requirement."
Regardless of whether metajustificatory foundationalism is committed to fallibilism, on the face of it, it looks as if Scripturalism is committed to traditional foundationalism anyway. As Fantl notes, defenses of and attempts to convince others that a proposition should be believed as basic and self-justifying need not be the grounds for our own belief that a proposition is basic and self-justifying. And yet our belief need not be arbitrary, for the proposition may need to be self-justifying if we are to avoid skepticism.
In the case of Scripturalism's sufficient (and itself necessary) condition for knowledge - the axiom of revelation - we cannot supplement its justification with some feature not inherent in the propositional content conveyed: "The Bible alone comprises the extant extent of that which men can know: i.e. divine revelation." Someone asks us how we know that, we answer that such is self-justifying. We can know it because it is true.
Now, the precondition of a self-authentic, omniscient communicator (link; link), for instance, can show why this sufficient condition must be self-justifying in order to avoid skepticism - hence, the sufficient condition is not arbitrary - but that does not make these subordinate preconditions for knowledge our grounds for believing our foundational axiom. The truth is just the reverse. Each of these propositions must be true - so the acceptance of one implicitly requires acceptance of the other - but our knowledge of the sufficient condition for knowledge must logically precede knowledge of subordinate preconditions (link). In fact, this is an implication of the aforementioned subordinate precondition: supposing a self-authenticating communication from one who is omniscient is a precondition for knowledge, we must have first identified and used that very communication to have established that very supposition. The importance of a subordinate precondition is that it can be as a reductio ad absurdem against the positions of people who don't agree with our epistemic foundation, not so that we can somehow provide a reason for or metajustificatory feature of our own epistemic foundation.