My dialogue with Ryan appears to be winding down. Much of this involves an intramural debate between Scripturalists. I'll bypass most of that and zero in on two paragraphs:
I’m not sure if Steve is saying we can’t extract Christian theology from Scripture or if he is implying that the “data base” of indubitable, indisputable truths can’t refer to Scripture. If the former, we can extract Christian doctrines from Scripture: the incarnation and divinity of Christ, the resurrection, a basic outline of Trinitarianism with various possible models, predestination, etc. If the latter, why not?
People can dispute that Scripture is indubitable or indisputable. But people can also dispute laws of logic and so forth. The question is whether in doing so, are they being inconsistent? Are they subverting their own ability to be internally and infallibly justified in believing anything? In the case of disputing Scripture, the Scripturalist says yes, they are. The conversation can then move on to whether we even need that kind of belief (on which, see here).
i) Let's begin with exposition. When I refer to Scripturalism, I'm bracketing Ryan's own position. Ryan is an independent thinker, and his position is a work in progress. I'm referring to Scripturalism in general.
In that regard, Scripturalism is a variation on modern classical foundationalism (e.g. Descartes, Chisholm). Modern classical foundationalism has antecedents in Plato and Socrates.
ii) Plato was on a quest for epistemic certainty. He distinguished between the sensible world, which was deceptive due to its mutability, and the domain of abstract universals. What you perceive with your sensory organs is not a reliable source of knowledge. Only what you can intuit, only archetypal ideas, constitute a source of true knowledge.
iii) In addition, you have what Peter Geach dubbed the Socratic fallacy. The notion that you can only know what you can define. Likewise, that you must begin with criteria.
The style of mistaken thinking -- as I take it to be -- that comes from accepting these two assumptions may well be called the Socratic fallacy, for its locus classicus is the Socratic dialogues. (371) The assumptions: Let us rather concentrate on two assumptions that Socrates makes: (A) that if you know you are correctly predicating a given term 'T' you must "know what it is to be T," in the sense of being able to give a general criterion for a thing being T; (B) that it is no use to try to arrive at the meaning of 'T' by giving examples of things that are T. (B) in fact follows from (A). (371) Geach goes on to argue that the "Socratic fallacy" is a fallacy: We know heaps of things without being able to define the terms in which we express our knowledge. Formal definitions are only one way of elucidating terms; a set of examples may in a given case be more useful than a formal definition. (371) In addition, Geach seems to suggest that the Socratic fallacy accounts for the fact that the Socratic dialogues usually end up in aporia: We can indeed see in advance why a Socratic dialogue so often ends in complete failure to elucidate the meaning of a term 'T'.... But if there is no initial agreement either on examples of things that certainly are T or on criteria for predicating 'T', then the discussion is bound to be abortive .... (372) How harmful the rejection of examples may be we see from the Theaetetus. Theaetetus, asked what knowledge is, gives some instances of knowledge -- geometry and shoemaking and the various crafts. Socrates objects that these are only examples, and he wants to know just what knowledge is .... But of course any knowledge is t.
iv) This, in turn, is related to what Chisholm dubs the problem of the criterion:
To know whether things really are as they seem to be, we must have a procedure for distinguishing appearances that are true from appearances that are false. But to know whether our procedure is a good procedure, we have to know whether it really succeeds in distinguishing appearances that are true from appearances that are false. And we cannot know whether it does really succeed unless we already know which appearances are true and which ones are false. And so we are caught in a circle.
A popular form of the Problem of the Criterion can be raised by asking two seemingly innocent questions: What do we know? How are we to decide in any particular case whether we have knowledge? One quickly realizes how troubling the Problem of the Criterion is because it seems that before we can answer the first question we must already have an answer to the second question, but it also seems that before we can answer the second question we must already have an answer to the first question. That is, it seems that before we can determine what we know we must first have a method or criterion for distinguishing cases of knowledge from cases that are not knowledge. Yet, it seems that before we can determine the appropriate criterion of knowledge we must first know which particular instances are in fact knowledge. So, we seem to be stuck going around a circle without any way of getting our epistemological theorizing started.
v) In modern classical foundationalism (a la Descartes, Chisholm), you distinguish between immediate and mediate beliefs. Immediate beliefs aren't based on other beliefs, while mediate beliefs are based on immediate beliefs.
Knowledge has a logical structure in which immediate beliefs function as axiomatic first principles. Mediate beliefs are inferred from immediate beliefs, by deductive logic. By contrast, inductive logic is a "fallacy."
To qualify as an immediate belief, it must be self-evidently true, unmistakable, and/or certain. Immediate beliefs share epistemic immunities. They cannot be in error. They cannot be reasonably doubted.
There are two kinds of immediate beliefs:
a) Simple, abstract necessary truths of math and logic (e.g. 2+2=4, modus ponens; "If Bill is taller than Bob, and Bob is taller than Bud, then Bill is taller than Bud")
b) Self-presenting states (e.g. "there appears to be a tree in my field of vision").
The method of arriving at true knowledge is to begin, not with the sensible world, but with your own mind. Intuition and introspection.
Strictly speaking, only immediate beliefs are certain. In principle, due to the transitive law, a mediate belief that's validly deduced from an immediate belief is just as irrefragable as the immediate belief itself.
But in practice, it lacks the indomitability of an immediate belief because chains of logical inferences may contain subtle fallacies which we fail to detect. Take Andrew Wiles' proof of Fermat's Last Theorem. Only a handful of number theorists can even grasp the technical, complicated argument. Therefore, even if the argument is valid, it is hardly self-evident or indubitable in the sense that 2+2=4.
vi) The problem all this poses for modern classical foundationism is that if you insist on that stringent definition of knowledge, then belief in other minds, belief in a physical world, belief that you have two hands, belief in the reality of the past, is unjustified and irrational. For instance, you can't disprove Last Thrusdayism: "There is no logical impossibility in the hypothesis that the world sprang into being five minutes ago, exactly as it then was, with a population that "remembered" a wholly unreal past. There is no logically necessary connection between events at different times; therefore nothing that is happening now or will happen in the future can disprove the hypothesis that the world began five minutes ago."
By retooling some theistic proofs, you may be able to salvage belief in a God, but beyond that, along with a residuum of infallible, indubitable beliefs (self-knowledge, self-presenting states, and simple logical or mathematical relations), nothing else rises to the level of knowledge. Perceptual and memorial beliefs are preemptively disqualified.
vii) Scripturalism retains the basic criteria and framework of modern classical foundationalism. It tries to replace the set of immediate and mediate beliefs with Biblical propositions and logical inferences from Biblical propositions. The structure of knowledge is formally similar to modern classical foundationalism. An axiomatic system.
However, their criteria go back to Socrates, Plato, and Descartes. But those criteria prohibit internal access to Scripture as an object of knowledge. There's the dilemma of vicious circularity: "the problem of the criterion" (see above). And there's the Cartesian demon. Given that thought-experiment, Scripturalists can't justify their faith in Scripture. They lack direct access to Scripture. They only have direct access to their own mental states, which–for all they know–may be delusive.
viii) I don't object to using Scripture as a touchstone of knowledge. And I think we can develop and deploy TAGs. But that will be abortive if we adhere to the criteria of classical modern foundationalism and its philosophical antecedents.