David P. Hoover on Gordon Clark

As I would expect Van Tilians to be able to reply to his impressive criticisms of Van Til’s apologetic (link), I think his paper on Clark (link) is equally deserving of a reply from a Clarkian. Insofar as I do not agree with everything Clark wrote, perhaps I am ill-suited to the role, but I agree with Clark in many respects – especially epistemologically – so until someone smarter than Hoover and I comes along and sets us both straight, I will try to fill in a few gaps.

Background and Terminology

Briefly, I will point out that some terminology Hoover uses could be perceived as biased since provided without much explanation. In his introduction, for instance, he writes that “Clark is an uncompromising Idealist and Rationalist.” Now, the idea that Clark was an Idealist is debatable; Clark didn’t necessarily have a problem with it (Clark and His Critics, 2009, pg. 209), and for that matter, nor do I if Idealism is defined as there being a significant sense in which there is no reality independent of God’s mind. Univocal [real] images, for example, are as possible as univocal [real] propositional knowledge; this will be important to remember when discussing how the coherence theory of truth could be supplemented, though it must also be acknowledged that empiricists bear a burden of proof when it comes to so-called knowledge about some allegedly corresponding image.

But given that Hoover was familiar with Clark’s book Three Types of Religious Philosophy, in which Clark differentiates his “Dogmatism” from Rationalism by denying that “all religious knowledge, can be deduced from logic alone, i.e., logic apart from both revelation and sensory experience” (Christian Philosophy, 2004, pg. 21), why Clark is classified as a Rationalist is a bit of a mystery. Whereas “Rationalism believes that it can deduce by its own method what God can and cannot say” (Ibid., pg. 42), Clark held that divine revelation is necessarily self-authenticating. Hoover is fair in his exposition of Clark in most other respects, so it is strange that he does not explain why he considers Clark a Rationalist. He highlights their similarities - such as the acceptance of the coherence theory of truth - at the expense of individuating characteristics.

I do not mean to suggest that Hoover intentionally fails to provide all the pertinent facts. I suspect the real trouble here and elsewhere is that the scope of the article is inherently restrictive. In my opinion, Hoover was given a 10,000 word limit or so to explain and then critique the epistemology of a man who wrote several dozen books on it and dedicated his life to teaching it. Quite possibly, Hoover could have anticipated the sorts of questions I am and will be asking but felt that addressing them would be too tangential or less relevant than what he would have had to cut out. Naturally, Hoover is also not only or perhaps even chiefly writing for readers who are already familiar with Clark, so the space available to present a comprehensive rebuttal - let alone a defense of his own thoughts - is mitigated by the purpose of the article: the focus is meant to be on Clark, not Hoover (so far as this is possible), and the historical “progression” of his thought as well as an evaluation of it. Of course, none of this will prevent me from remarking on what is left unsaid that I think is important, whether or not such was deliberate.

On Induction

Hoover’s abstract reads as follows:

Gordon Clark is an uncommon presuppositionalist. Dating roughly from the publication of his “Wheaton Lectures” in 1968, he has increasingly stressed the complete impossibility of empirically acquired knowledge. According to Clark, the Bible, and only the Bible, can be known. All observation based truth-claims and all inductive arguments are logically worthless for apologetic purposes. This essay attempts to follow the progression in Clark’s thought which leads to such a thoroughgoing skepticism (with regard to a knowledge of the contemporary world). The essay looks, in turn, at Clark’s reasons for rejecting the reliability of perception, Clark’s adoption of the Bible as axiomatic, and Clark’s propositionalism. Although these subjects are treated critically, the aim of the author is to achieve clarity on what Clark holds and why.

Hoover similarly states a little later, “Valid reasoning, for Clark, is the only profitable reasoning one can engage in, and it is definitionally deductively valid reasoning. Inductive arguments whose premises merely support their conclusions are necessarily bad arguments - in fact, worthless.” These ideas warrant further explanation than I think was provided in the article. Clark did agree with Plato that “Knowledge is timeless and changeless and requires, not observation, experiment, and induction, but deduction alone” (Ancient Philosophy, 1997, pg. 141). He also said that “there is no logical place for induction in presuppositionalism. One assumes or presupposes certain axioms and from there on everything is deduction” (The Trinity, 1990, pg. 93). So, if Hoover is meaning only to refer to the fact that “unnecessary inference arrives at no truth at all” (Lord God of Truth, 1994 pg. 39) - as I suppose he could be, given his qualification that Clark argued induction is “logically” worthless - Hoover is as entirely correct in his assessment of Clark as Clark is of induction.

But all of this only pertains to Clark’s own positive, [meta]epistemological views. A recurring theme throughout this post will be that Scripturalism is a philosophy which attempts to promote and supply the need for infallibilistic knowledge. Insofar as an apologetic or belief is unnecessary, it isn’t epistemically relevant - which is, I stress, not to say it is completely irrelevant. But what we need, what we must have - in short, that which is necessary - should come first, and fundamentally, this is “philosophical knowledge.” Induction, therefore, cannot be epistemically profitable, but at the same time, Clark’s philosophy is compatible with the opinion that induction can serve a pragmatic function. And even in the context of apologetics, Hoover notes elsewhere that Clark believed:

The apologete can take up archaeology only in its potential for logically embarrassing the opponent to Christianity. That is, “scientific discourse” can be taken up only ad hominem against the individual who puts credence in science.

Thus, it is somewhat misleading to suggest that the ability to refute or disconcert an opponent with his own methodology is “worthless,” even if the methodology itself can (and should) be demonstrated to be so; in fact, assuming his faulty basis in order to show it leads to [other, more overtly recognizable] undesirable beliefs seems to me to be a rather common-sense apologetic attempt to persuade an individual that it is his basis that is in need of correction. Apologetics needn’t be restricted to the providing of a defense of one’s own position, although and notwithstanding Hoover’s seeming disagreement (cf. footnote 24), that is certainly a precondition for an analysis of another’s (link).

Cognitivity and Sentience

Early on in the article, Hoover does a relatively good job of restraining himself from incredulous dismissal of the consequences of Clark’s arguments, evident, for example, in the following:

The very legitimacy of questioning the reliability of sentience (the capacity to discriminate the environment by the senses) seems to imply that there are perhaps other (non-sentient) modes of cognitive access, other methods for finding out, that might be used instead. And if sentiently gleaning content goes part and parcel with inductive method, then the question becomes whether there is a better method than observation and testing to find a cure for AIDS. But what might an alternative be like? Divination? Inspecting tea leaves? Saying the first (second, third) thing that pops into one’s head? (Observing tea leaves is, of course, ruled out.) Or perhaps there is no such disease as AIDS since its occurrence is alleged on the basis of observation! And by parity of reasoning there are no diseases afflicting anyone! But if we find that we cannot help but admit that we do have the capacity for making observations in God’s world and that sentience is inextricably tied up in the making of observations, we will find Clark’s position even startling. But it is important to state that Clark’s position cannot be put away by a string of rhetorical questions.

Still, a few points on Clark’s behalf seem to be required. In the next section of his article, Hoover correctly writes that “Clark’s ultimate concern for presupposing, it seems to me, is more nearly the philosophical one of overcoming skepticism (by exhibiting at least one logically irrefutable truth).” But in that case, what do “the reliability of sentience,” “the reliability of perception” and “cognitive access” to one’s environment entail? In particular, do any or all imply one should be able to have infallibilistic knowledge of his environment? If so, why does Hoover even think one needs to know his “environment” in the first place, assuming there even is such an environment? If not, then I do not see how any of this is relevant to the business of Clark’s epistemology given what Hoover himself acknowledges to be its primary concern: the refutation of skepticism by the establishment of infallibilistic knowledge.  Other theories of “knowledge” may ask that less stringent conditions be met, but for that very reason Clark would not be as interested in them; they would have no value in making headway toward Clark’s goal. In one of his footnotes, Hoover says: 

...the fact that informal cognition (knowledge by sentient acquaintance) is subject to well-known limitations and pitfalls does not argue that there can’t be sentient acquaintance with the world. To have a cognitive capacity does not entail the having of it to a superlative degree or the having of it without limitation with regard to the sort of capacity it is. 

But would Clark necessarily disagree? After all, Clark does at times informally refer to sensation as that which stimulates actions designed to preserve the body from [perceived] harm or an occasion on which knowledge occurs (cf. Lord God of Truth, pgs. 16, 23); at least, I am not aware that he has provided a strict definition of it, although he certainly chastised those who attempted to found their philosophy on it without defining it. So it’s not so simple as Hoover’s conclusion that “Clark simply refuses to acknowledge informal noetic capacities in man.” It’s not a question of whether we must have “faith that we inhabit a real and discriminable world of real and discriminable sinners” in order to evangelize or whatnot. Clark agreed that we should act as if all our beliefs (opinions included) are true:

Although not usually recognized as such, a certain claim to infallibility meets us in our everyday affairs. When an accountant balances his books, does he not assume that his figures are correct? When a college professor hurries to class for fear that his students will disappear if he is late, does he not make judgments as to the time of day and the proclivities of students? When a chess club challenges another to a match, does any suspicion of fallibility impede its action? Cannot this club distinguish the dogma ecclesiastica that there actually is another club from the dogma haeretica that no other club exists? Must not all people act on the assumption that their beliefs are true? (Karl Barth’s Theological Method, 1997 pg. 146)

But it is clear that all of this is has nothing to do with whether our inferences not based on divine revelation can be infallible, let alone why they need to be (link). I am pretty sure, then, that Clark would ask Hoover if or how he infallibilistically knows he has this capacity. How does Hoover account for how Timothy could infallibilistically know he has found Paul’s cloak? Or doesn’t he? If Hoover were to demure but protest that Clark is being reductionistic - as he does in the rest of the aforementioned footnote - I think Clark would say this is all besides the point, for the refutation of skepticism requires a narrower focus as to what sort of knowledge could count as a defeater. Hoover may not care as much about skepticism as does Clark, but then it would be an “empiricist” rather than a “rationalist prejudice” that is at issue here. 

Additionally, regarding so-called “ostensive clarity,” Hoover never really explains how or if one can discriminate between conflicting claimants. This may have less to do with Hoover and more to do with whatever particular brand of empiricism he espouses, but it’s hard to tell because nearly all allusions to it are either mentioned in passing or phrased in such a way that the reader is not sure whether Hoover is committed to the idea in question. 

On the one hand, Hoover says “What is important to see is that one cannot discredit [ostensive (or inductive) demonstrability] by showing that it cannot be analyzed in terms of [discursive demonstrability].” Does that not also imply one can’t be credited over another? Epistemologically, that would be a point Clark would consider in his favor.

On the other hand, Hoover clearly wants to avoid arbitrarity. In one footnote, he suggests that empiricists “can maintain that there is an intimate and necessary relation between sensory stimuli and the perception facilitated thereby, but deny that stimuli and perception relate by logic. A stimulus, after all, is a stimulus a causal sort of thing.” In another, he says the possibility of “phenomenal indistinguishability... can be contested,” but instead of explaining how, he goes on to argue that our epistemological limitations don’t affect ontic statuses. Now, anyone “can maintain” any position. The real question is why he would. So wouldn’t it more be more helpful to explain what grounds an empiricist could have for these positions? Maybe he is presupposing them, though he continually seems to want to contrast presuppositionalism with his evidentialism. 

Why, then, does Hoover think sensations cause perceptions? And then how can perceptions be used to form abstract concepts or universals? I mean, there must be some point at which propositional beliefs are connected to sensation, perception, images, etc., right? I had thought that was the whole point of “empirical” knowledge. But since the predication of truth-values is propositional enterprise, then in contrast to what he states above, mustn’t there be discursive reasoning or logical relations somewhere in this empirical process? Well, where and how?

In yet another footnote - which one can probably by now sense is where most of Hoover’s positive [counter-]assertions have unfortunately been relegated - he writes: “From an aggregate of black dots which ostensibly occupy an area on a newspaper page, one cannot deduce the likeness of President Reagan. The President’s likeness is gestaltic in character, not discursive.” What does that mean? Does one have legitimate reason to infer a resemblance to President Reagan or not? Could one have legitimate reason for denying a resemblance? What suffices as a “likeness”? The reader is left guessing. If this is all purely intuitional - Hoover asserts that “there is an inherent informality in the very meaning of truth and in the human being’s mode of cognizing truth” - then I would consider empirical knowledge to be rather arbitrary and subjective.

Ironically, Hoover is so busy chiding Clark for “begging the question” against empiricists when he agrees with Blanshard in one instance or picks apart empirical particularities which Hoover doesn’t hold to in another - as if Clark were always obliged to refute all of empiricism and all empiricists universally and at once or else refrain from making any attempt at refuting individual arguments empiricists have used - that in the remaining space it seems he can do little more than make offhanded comments about or references to what he does hold to and why. But this in turn begs questions too. If Hoover’s empiricism really is so different than that of those whom Clark critiqued, I would have expected a bit more effort to distinguish his views, especially given his insistence that Clark’s opponents did not actually “fail to identify clear alternatives.” 

Anyway, when the reader recalls that this article was written in 1984, only one year before Clark’s death, it should not surprise him that the mainstream views of contemporary empiricists (like Hoover?) should have changed so quickly from what the mainstream views of the empiricists of yesteryear believed. Clark himself noted this as a recurring trend throughout the history of philosophy. When it comes to secularly approved epistemologies, the only constant is change. Then again, even if none of what he said in his books is applicable to modern empiricists - which I doubt - Clark can hardly be held responsible for not responding to empirical ideas which had not yet been invented when he originally published them. But this is an impression one can sometimes receive from Hoover’s article.

The Coherence Theory of Truth

Hoover defines the coherence theory of truth as follows:

Briefly, the coherence theory of truth holds that there is only one ultimately coherent system of truth. Truth, that is, is a system of geometrically organized propositions. If a certain proposition is true, it is logically entailed by the system—or less stringently perhaps, a true proposition is one which is simply not inconsistent with any of the other propositions in the system. On the other hand, a proposition is false if and only if it fails to be entailed by the system—or, if and only if it is inconsistent with the system. The system contains all truth and only a truth can properly be said to be a knowable.

In the case of an omniscient God, I don’t think an analogy to geometry is appropriate, but this is a bit technical. So far as a human like Clark, Hoover, or myself would be concerned, this is a fine explanation. And Clark does hold to the coherence theory of truth to the exclusion of all others (cf. Today’s Evangelism: Counterfeit or Genuine?, 1990, pg. 111; “The Bible Today” 42.6, March 1948). But while I think Hoover is correct to criticize Clark for holding to it exclusively, I don’t think he goes about it the right way. Hoover argues:

The telling criticism, however, is that, contrary to Clark’s belief, the coherence theory of truth does not provide a theory of the meaning of truth, but only a criterion for its recognition within a formal system. Thus, if presented with a proposition P, and I know that P is a member of a set of propositions which is consistent, then if that set is sanctioned by a true axiom, P must be true as well. The mere coherence of P is a sufficient criterion of its truth. But note that P’s content, by the coherence criterion, is irrelevant. My point is that a sure—fire criterion for the identification of a true proposition as a true proposition is not necessarily an insight into the meaning of truth. 

But for the moment, let us suppose that the coherence criterion is also the meaning of ‘true’ as predicated of propositions. Suppose that Clark is right. Take the proposition, “Jesus Christ has come in the flesh.” (I John 4:2). The recipients of John’s letter, let us assume, rejoiced in this truth as over against the docetic teaching about the incarnate Christ. But in what, exactly, could they have rejoiced given that the coherence theory of truth is true? If we are indeed given the meaning of truth by the coherence theory, then John’s proposition’s truth consists in its formal consistency with the larger set of propositions of which it is a member. They rejoiced, then, that “Jesus Christ has come in the flesh” is logically consistent with all the other propositions they held for true. Conceivably, there may have been in that early church some rather eccentric academics and logicians who had the necessary expertise to delight in the logical fittingness of John’s statement, but did not the early church rejoice rather in this statement’s content? In what this statement is about? The Apostle John’s faithful witness is that we do not serve a docetic Christ, but a Christ who became flesh. The proposition in question, if we are to make sense of being encouraged and gladdened by it, is about a non-proposition—viz., the Incarnation of Christ. Its coherence may be a criterion or sign of its truth but its truth is more plausibly construed as its faithful recounting of what had taken place in the case of Jesus of Nazareth. So unless a mere mark of truth is the meaning of truth, coherence cannot be definitional of truth.

Maybe I’m missing something, but in the second paragraph, it just seems like Hoover reverts to the string of rhetorical questions he had earlier acknowledged would be insufficient for the purposes of his article. Clark would say a proposition is “about” whatever is the subject of the proposition. Then what?

As for the first paragraph, I don’t understand why Hoover thinks that “P’s content, by the coherence criterion, is irrelevant.” How could one gauge coherence between two propositions unless he can compare their content? 

Furthermore, as hard as it is to believe - which is why I say I could be missing something - it looks as though Hoover conflates the coherence theory of truth with coherentism. The former has to do with what truth is as such; the latter has to do with the “recognition” of it. These don’t refer to the same thing, though they may seem to. The latter is essentially a theory of how we can justify some knowledge-claim, and as a Scripturalist, Clark certainly didn’t think we know a proposition is true if and only if it coheres with other propositions. He acknowledged this could be possible in the case of God (cf. Clark and His Critics, 2009, pg. 287ff.), but he equally makes clear that he doesn’t consider coherence a “sufficient criterion” for men. “One who believes in the unity of truth may still believe that the false system entails contradictions; but to prove this is the work of omniscience” (Historiography: Secular and Religious, 1971, pg. 370). So our [justified] knowledge of what truth is as much depends on divine revelation and that which can be derived from it as anything else.

Instead, I think it is better to attack the metaphysic which undergirds an exclusive adherence to the coherence theory of truth. If there are realities other than propositions and the concepts of which they are composed, then one who [correctly] believes that everything is related will have to relate his theory of truth to that. Earlier, I noted Hoover calls Clark an Idealist and that this is not necessarily false or a bad thing. But I would argue and have argued (see here, here, here, here, and here), however, that if Idealism implies the “propositional monism” to which Hoover attributes to Clark - viz. that “the set of all real objects and the set of all knowables is the same set” - this metaphysic is inconsistent with Clark’s stated philosophy, which in the main is sound. 

Persons

While what has been said above may address the concern that “Clark’s epistemology requires a serious distortion of human nature, to that extent it is ill-suited to serve as a basis for defending the Christian faith,” Hoover also questions Clark’s metaphysical thesis of persons as a congeries of propositions [or, perhaps a little more precisely, thoughts]. Now, as Hoover says upfront that he wishes to “sketch a reductio ad absurdum argument against Clark’s insistence that persons are propositions,” the challenge will be to refute Clark while operating within Clark’s epistemological framework. Indeed, as the Bible just is a series of sentences, and the Bible alone is, on Scripturalism, the source of all [infallibilistic] knowledge, the only way to show to Clark that there are realities other than sentences is if it is shown that sentences are in some respect deficient in explaining things the Bible refers to. So it might be true that on Clark’s metaphysic of persons, propositions must be regarded as bearing capacities or properties like moral character, rights, and so forth, but Hoover’s conclusion that this is “curious” seems to dangerously imply that Hoover is begging the question. But then he says that this is not “formally decisive,” and so we are really just left with the following paragraph:

According to Clark, persons are propositions (i.e., “complex definitions”). Drawing from Leibniz, Clark affirms that a given person is precisely the set of propositions that make up his life history. And a person is all his propositions. From this it follows that personal identity, self-knowledge, is utterly problematic if not impossible. This follows for two equally sufficient reasons—the first posing a strictly epistemological problem and the second, a logical problem of individuation: (i) Epistemologically, at any point in one’s “autobiography” one has only a finite sample of a possibly infinite set of propositions that will go to constitute his identity. Recall that propositions based on sentient awareness do not count. Now if one has but a finite sample of propositions relevant for his/her identity, the probability that one has enough propositions for a correct identity judgment is either exceedingly small or zero (a finite number over infinity is zero). (ii) Logically, Clark’s theory identifies the person as a “complex definition”—or, to say the same thing in a way that will help us make the point about individuation more clearly, a person is a set of propositions. Persons, then, are individuated by propositional sets, by propositional totalities. This has the exceedingly odd consequence that persons can be told apart, so to speak, only by virtue of their entire life histories. Because no person in this life has the requisite omniscience to know total life histories, it follows that persons in this life are not the sort of thing that can be told apart. But perhaps more seriously—and this brings us around to the test question concerning the exercise of moral agency—if persons are thus individuated (by logically complete propositional sets), how is it imaginable that persons could be moral agents within their life histories? For in Clark’s sense of person, the person seems to be his life history and not a participant within it. And it does no good to invoke the omniscience of God. The fact that God can individuate the propositional sets in question still does not allow persons to be agents within history. Propositional sets are simply not the sort of entities that could commit adultery, care for the sick, or resist temptation. Thus it would appear that a propositional monism is insufficiently rich in basic categories to allow even the Biblical David to sin and repent. 

Now, I have defended the possibility of self-knowledge with a Scripturalistic framework here, among other places. I also think I’ve also pointed out a fallacy in the idea that a function in which x is some finite number and y approaches infinity equals zero when the former is divided by the latter (link). 

In response to the other arguments, that we cannot now knowingly individuate ourselves would not be to say that it cannot be done, nor that we cannot have an opinion as to how we are distinct subjects. This may remove some of the sting of the criticism, at least until it is explained why infallibilistic knowledge [of ourselves or, for that matter, extra-biblical realities in general] is necessary in order to obey God.

I do think Clark was a bit unclear as to whether a person is “what he thinks” (The Trinity, 1990, pg. 129) or, in agreement with Leibniz, whether a person is the sum of what may be predicated of him (cf. Clark and His Critics, 2009, pgs. 148-149). Maybe he thought these two ideas can be resolved.  But I didn’t really understand the criticism that a “person seems to be his life history and not a participant within it.” On Clark’s view, how could there be the former without the latter? Perhaps Hoover’s philosophy of time or history is different from Clark’s, but if so, he never says it.

In short, Hoover seems to be attacking all the right doctrines in all the wrong ways. While I agree with his conclusion that persons cannot just be propositions, I provide other reasons for it (e.g. here).

Language

While I don’t seem to agree with many of his answers, Hoover does ask some really good questions. On the subject of language, he writes:

What it means to presuppose the truth of all this content is itself far from clear. And the question is important beyond a mere philosophical quibble. For one thing, there is the character of truth itself according to the different presuppositionalists. Does truth attach to locutions within the various literary genre in a univocal way - e.g., in poetry, didactic passages, historical narrative? How does truth qualify, and provide implication for, imperatives, interrogatives, counter-factual subjunctives? When one avows that one “presupposes Biblical truth” one does not, ipso facto, answer this sort of question.

These are all excellent, each deserving of more development than I have the present capacity to give. I have written about counter-factuals here. Regarding imperatives and interrogatives, they must mean something just as declarative sentences must mean something, and we must be able to understand them. So perhaps it is possible to reformulate these types of sentences in declarative form without a loss of meaning. For example, per Augustine, a question could normally refer to an expression of desire that a person teach him about some subject. A command could be thought of as an [assumed] authoritative declaration that one [is obligated to] perform some action. In any case, both types of sentences connote that the utterer has certain hopes or expectations of his interlocutors. As for there being various literary genres, even such being the case, one point they all must have in common is to communicate some understandable meaning, in which case historical-grammatical exegesis should be able to be indiscriminately applied.

But Hoover makes other, more provocative relations between language and Scripturalism, such as:

Suppose, for example, that I want to determine whether “Hoover is using the Axiom” (1) makes sense, and (2) whether it is true. Since on Clark’s assumptions knowledge is the system headed by the Axiom (as identified), the individual terms if they can be assigned content, must be defined in the Axiom, and the proposition as a whole is certifiably true only if it is either mentioned in the Axiom or deducible from the Axiom. Taking the truth of “Hoover is using the Axiom” first, we see at once that it is neither mentioned in the Bible nor is it deducible from the Bible. It follows that I, Hoover, can never know whether I am using the Axiom—whether reading, applying, or reflecting on it. More drastically, perhaps, the very proposition “Hoover is using the Axiom” contains one prominent term for which no Clarkian meaning can be assigned. On the criteria already given, no acceptable definition of “Hoover” can be acquired. Hence, it seems to me, the formula “Hoover is using the Axiom” fails to constitute an intelligible proposition. 

As for the idea that something must be explicitly defined in order for one to be able to understand what it means, I see no reason why, if every concept is “a name given to a very lengthy complex of propositions” (Modern Philosophy, 2008, pg. 273), our ability to understand what any one of them means cannot be due to meaning that is inherent or implicit in their usage. After all, if concepts are like empty receptacles into which meaning is poured, defining a concept by making it a subject of a proposition is no good, for the predicate turns out to be just another empty receptacle. See here and here for more on the ideas of necessary and intrinsic meaning.

Now, when it comes to the ontology of man, the “innate knowledge” of language and logic which is evoked upon “the heat of experience,” and so forth, there is much more that can and must be said. But given these available speculatory answers, Scripturalism doesn’t stand or fall here (link), so I will leave further thoughts for another time.

David P. Hoover on Van Tilian Analogical Knowledge

David P. Hoover was the evidentialist who debated Gordon Clark in 1983 (link). He also wrote an article one year after that debate, doing a much better job of critiquing Clark’s views than in that debate (link). Perhaps that is because he is in general a better writer than speaker - for he is a good writer - or perhaps that is because after the debate he better acquainted himself with Clark’s works. Regardless, some of it pinpoints sore spots - especially those which concern metaphysics - other parts, not so much. I don’t consider it to be fatal to Scripturalism, for whatever that’s worth.

While I may interact with his article on Clark some other time - which would probably be more entertaining for the reader than the unprecedented number of posts on Van Til[ians] these past few weeks, which I do not anticipate will continue hereafter - I wanted to provide a link to an online critique he wrote of Van Til’s apologetic (link). It’s a bit informal for my taste - especially after pg. 45 - but as a former Van Tilian, it is instructive to see what he believed to be the problem areas in Van Til’s philosophy. This includes his comparison of Van Til to Kant (pgs. 56, 104-105), his confirmation of my suspicions in my previous post that analogical knowledge is grounded on an acceptance of the doctrine of internal relations (pgs. 13-14, 72), and, particularly, the doctrine of “analogical knowledge,” i.e. the doctrine that the content of God’s knowledge and the content of man’s “knowledge” neither qualitatively nor univocally coincide at any point. 

Naturally, as Hoover is an evidentialist, I don’t agree with everything he writes, but so far as his internal critique of Van Til is concerned, I’ve categorized the following arguments against analogical knowledge which I found to be persuasive. Analogical knowledge:

1. Has Self-Referential Problems

Since Van Til insists that reasoning analogically is a necessary condition of knowing truly, it must be possible to tell, at least on some occasions, whether one has reasoned analogically. Yet according to Van Til, the ability to specify criteria would cancel the need to invoke analogicity in the first place. And why is that? Because to specify criteria entails a univocal access to at least some knowledge as God knows it in order to see whether one’s own noetic holdings are indeed analogous of God’s noetic holdings. That means we would have to have access above the ceiling in order judiciously to apply the analogy concept to our own thinking. But by the very nature of the case there can’t be any human peeking above the ceiling, for above the ceiling (as I am using this metaphor) there is only knowledge as God knows it. The very idea of human access to the latter is an ontological impossibility on Van Til’s reckoning, and things don’t get more impossible than that! So Van Til has put the Christian in the impossible position of having to “reflect” God's knowledge while being systematically cut off from it. (pg. 16)

So on Van Til's own logic, either (1) knowledge is impossible because no human belief can be analogically validated, or (2) “analogicity” itself, contrary to Van Til’s idea that he is somehow doing epistemology, is a speculative metaphysical concept which (somehow) merely characterizes human knowledge by contrast to divine knowledge. I say “speculative” because the only way Van Til could know (and hence not speculate) that there is “no identity of content” between divine and human minds is by peeking above the ceiling in order to confirm that this is so-and by his own principles creatures can’t do that.

Well, I think (2) is the case: Van Til’s theory is a speculative metaphysics of knowledge and has precious little to do with practical epistemological matters. That is to say, Van Til gives us no help at all with specifying applicable conditions by which to certify knowledge, and it is only if knowledge can be identified in total independence of Van Til’s metaphysical doctrine, that that doctrine can have even dubious application to the ultimate character of the knowledge thus (independently) identified. To repeat, Van Til provides not a clue about how we acquire ordinary knowledge, and how to separate ordinary knowledge from ignorance. Bottom line: Van Til’s “theory of knowledge” is not a theory of how we may come to know things by examining data and evidence, but is instead a metaphysics of the contrast he alleges between the mind of God and the mind of man. (pgs. 17-18)

…in the complete absence of univocal criteria there is the problem of commencing an infinite regress of analogical evaluations. Evaluation itself insofar as it is presuppositionally proper in its rationality, must be analogical, so only analogical evaluation is competent to assess the strength or merit of a putatively analogical argument. But how does one tell whether the assessment itself bears a sufficiently strong analogy to God’s thought? Answer: that would take another analogical assessment of the immediately previous assessment-and so on forever; and fourth, there simply is no ana-logic and hence no structural means to assess outcomes of reasoning which “reflect” (i.e., are analogical of) divinely held truth. (pg. 51)

2. Renders Apologetics a Pointless Enterprise

Criteria are marks or discernible characteristics by which we can test our knowledge. An inherently indiscernible criterion is self-contradictory-no criterion at all. Analogicity, needless to say, is an inherently indiscernible property, and a Van Tillian analogy is an inherently indiscernible relation. Hence Van Til’s analogy doctrine is incurably speculative and systematically unavailable to do any work in epistemology or apologetics. (pg. 20)

Here is how to construct your own haven. Choose a deity. (Linus has chosen the Great Pumpkin.) Declare that your deity is creator of all things and enjoys absolutivity with respect to knowledge because of his supreme level of existence. Then draw the implication that all human knowing is at best analogical of the deity’s knowing so that there is no identity of meaning between anything in the deity’s mind and anything in a human mind. Stop. At this point, analogicity is fundamentally criterial for whether or not anyone knows “truly.”

This criterion, however, is inherently the abolition of all criteria. When in place, it is complete license to run religiously and spiritually amuck, for not only is substantive content noncoincident, principles governing logical coherence (the law of contradiction, for example) are as well. That is because (1) the deity is the only true knower, (2) humans are absolutely dependent on the deity's knowledge for their analogical knowledge, and (3) the logic of analogicity necessitates, first and foremost, the radical severance of cognitive linkage between divine and human minds. In effect, analogicity is Van Til’s metaphysical guarantee that there cannot be a semantic bridge between divine and human minds. I hasten to add that once the logic of analogicity is in place, no amount of pious language can be thrown at the resulting problem to alleviate it of the catastrophic consequence we have seen. (pgs. 28-29)

3. Licenses Paradox

And what of the Great Pumpkin? Since we are forever cut off from criteria to apply the analogicity concept to this or that claim, Linus can easily help himself to it without fear of later refutation. Linus, like Van Til, knows what he knows, and what he knows he knows analogically! Or to put it another way, Linus’s “special knowledge,” like Van Til's, enjoys an utterly inscrutable “resemblance relation” to the deity’s knowledge. And since this relation is inscrutable, hence not cognitively penetrable by way of criteria, there is simply no way to test it - no way, that is, either to confirm it or disconfirm it. Indeed, no refutation could count without itself being blessed with inscrutable analogicity! In a manner of speaking, to “analogize” your position is thereby to “immunize” it from criticism. Thus (once one's system is analogized) data can never interfere with cherished beliefs, whether you're a Christian theist, a Pumpkinologist, or an Elvis worshipper. Bliss! (pg. 29)

It might be thought, however, that Van Til’s rule to show “the impossibility of the contrary” might be used decisively against The Great Pumpkin. In logic, this is simply the procedure of reducing one's opponent’s position to absurdity by assuming the truth of its major premises and deriving a contradiction thereby.

There is a decisive objection to this that Linus can make, however: it is analogicity in Van Til’s scheme that secures the Christian’s position, not the strict logical coherence of Christianity s doctrines or an infallible construal of evidences. Indeed, he concedes that Christianity fares poorly when it comes to assessing, by standard logic, the Trinity or the coherence of the aseity doctrine with God’s having created anything. “So much the worse for standard logic,” is Van Til’s reply, “the analogical condition of being in the truth is what (argumentatively) secures the Christian position. Logical laws themselves are relativized to God’s epistemic absolutivily.” But that response is equally available to Linus in behalf of the Pumpkin. Analogically apprehended mysteries are exempt from straight logical critique (univocal critique, Van Til would say). Van Til’s line has always been that ‘contradictions’ at the core of the Christian faith are proper ‘mysteries’ while ‘contradictions’ at the core of opposing systems are conclusive evidence of their impossibility and falsehood. That is a darkish saying indeed. (pgs. 51-52)

4. Precludes Divine Omniscience and Communicability

…suppose that the “no identity-no coincidence” doctrine were true: in that case an omniscient God cannot entertain in his mind whatever the disciples did understand by his utterance! That is because the “no identity-no coincidence” doctrine is symmetrical. Regarding the prospect of communication, we must hold Van Til to his words: for both God and man “no identity” is no identity and “no coincidence” is no coincidence. So not only can't the disciples univocally entertain any of God's meaning; God can't univocally entertain any of the disciples’ meaning!

Van Til’s doctrine thus effectively renders divine-to-human as well as human-to-divine communication impossible so far as sameness of content meaning is concerned. And to boot (and ever so ironically), Van Til’s doctrine of analogy implies that an omniscient God is ignorant of the disciples’ precise understanding of him. (pgs. 22-23)

5. Restricts Divine Omnipotence

…there seems to be an ultimate irony in Van Til’s analogy doctrine, for that very doctrine places a rather catastrophic limitation on what an “omnipotent” God can bring about with regard to communication between himself and his creatures. To use a grammatical construction from Paul [Rom. 3:4], it is as though Van Til were saying, “Let God be incomprehensible and every man hopelessly ignorant!” Paul's actual comment, of course, is, “Let God be true and every man a liar!” Lying, unlike irremediable ignorance, allows some discernment of the truth which one is lying about. Paul's point, as I understand it, is that even if all men remained in unbelief through their own deception and self-deception, the truth of God and its epistemic availability would remain unaffected. If, however, God had created all men with an epistemic endowment that is semantically blind to divine revelation (blind, thus, merely because of human creaturehood!), then while God's truth would remain unaffected, it would be radically unavailable to man. And to provide emphasis, that is because if the ontological situation is as Van Til describes it, the Creator is powerless to create a being with whom he can communicate “in the same voice.” (pgs. 27-28)

6. Begs and Leaves Unanswered Questions Regarding the Incarnation

As applied to Jesus, I think the analogy doctrine implies a strictly bifurcated mind (within the thought processes of the historical Jesus) in which there would have to be two radically incommensurable ways of structuring knowledge (one divine and the other human) neither of which can fathom the other.

This question can be asked too: If our omnipotent God can become human-take on the same flesh as we ourselves who are saved by Jesus's sacrifice [“univocal” flesh, so to speak]-why can’t God also share some same level meaning within the constraints of the linguistic structures that he himself created? If, however, we accept Van Til’s doctrine of absolutely different levels of divine and human existence, then the very logic of this acceptance would seem to preclude that God could become a man. The question I raise is whether God can violate “the radically different ontological levels of divine and human existence” to literally take on our humanity on our level of existence. Given what Van Til has had to say about these levels, I don't see how he can escape this kind of difficulty regarding the Incarnation of Christ. It seems to me that both with respect to the cerebrally facilitated knowing of the earthly Jesus, and with respect to the Incarnation itself, Van Til’s speculations do not bode well for orthodox Christology. (pg. 30)

I think that Van Til’s notion of analogicity wreaks havoc, for example, with historic Christianity's doctrine of the Incarnation; for if he were consistent, there could be no overlap of meaning - no coincidence - between what Jesus had in his mind according to his human nature vis-à-vis what Jesus had in his mind according to his divine nature. If Jesus’s own cognitive nature was at all constrained by human cognitive architecture, there's a formidable problem here. (pg. 58)

As a cognitive agent Jesus is a single ‘integrated’ perceiver, believer, and knower, and this must be held as being logically consistent with Jesus being both divine and human. The problem is that these elements cannot logically coexist on Van Til’s ontological doctrine-his ‘theology of knowledge’ so to speak. That’s because, as we’ve already seen, there is an infinite, or shall we say ontologically unbridgeable, gap between divinely structured knowing and humanly structured knowing. In a nutshell, if persons individuate knowers, Jesus, on Van Til’s ontological doctrine, would have to be two persons, not one. That's the ancient Nestorian heresy, isn't it Charles?

And to come full circle, Schroeder, you weren't seeing the difficulty when you said, ‘He, Jesus, could know both analogically, because he’s a man, and univocally, because he’s God.’ Do you see the contradiction in that statement? When you say ‘he’ you can refer to only one knower. Van Til’s ontological principle absolutely forbids mixing, melding, or somehow homogenizing divine and human knowing. Or, if you like, it is fundamentally incoherent to say of an ontically unified knower that he knows an item of knowledge both analogically and univocally at one and the same time. So if the ‘he’ refers to a single and fully integrated epistemic agent (personhood requires this), then Van Til’s analogicity/univocity distinction cannot be applied to Jesus. (pgs. 59-60)

Hegelian Internal Relations and Van Tilian Analogical Knowledge

At the beginning of last year, I resolved a problem that had been puzzling me for quite some time: how is partial knowledge possible if everything is related to everything else? In that post, I made the following statement that I want to correct and clarify:

It is ironic that Van Til charged Clark with rationalism when Van Til held to the logical conclusion of Hegelianism. The doctrine of internal relations essentially states that “everything has some relation, however distant, to everything else” (link). If this is doctrine is true, as I think it must be – I may write a post on this later – then the question is begged as to how one can learn anything. I have argued (here, for example) that internal relations means that the source of knowledge must be an eternally omniscient being. 

The initial sentiment is true, but unfortunately, I confounded the doctrine of internal relations with the idea that everything is related to everything else. Well, my lingering confusion was pretty much what I deserved for relying on Wikipedia. Clark more precisely defines internal relations in Historiography: Secular and Religious on pgs. 225-226 (1971):

Reenactment of a thought is possible, nonetheless, because it can be separate from this immediacy without alteration. Not only so, it can be separated from other thoughts without alteration. Thus history becomes possible. 

This self-identity of the act of thought has been denied by two extreme views. The first view is that of idealism, the theory of internal relations, the notion that everything is what it is because of its context. This makes history impossible. To know any one thing it would be necessary to know its context; i.e. to know the whole universe. Knowledge would thus be restricted to the explicit consciousness of the omniscient Absolutes; and Collingwood, though he may be Beckett, does not claim to be the Absolute.

That is, the theory of internal relations does indeed posit that everything is related to everything else - an idea which I agree with and which Clark himself defends in the same book (cf. pgs. 179, 183) - but it does so in such a way that partial knowledge is impossible.

With this definition in mind, Clark's reference to "idealism" and especially "the [omniscient] Absolute" clearly indicates he is thinking about Hegel. Subsequent reference to Hegel on pg. 334 when mentioning the problem of partial knowledge also confirms this:

What follows if it is true that psychological analysis presupposes a “complete knowledge of the psychological possibilities of life”? It would follow, would it not, that historical analysis also presupposes a complete knowledge of historical possibilities. In short, it would be impossible to know anything without knowing everything. 

Such a Platonic or Hegelian requirement of omniscience is a serious philosophical problem. It is not to be dismissed thoughtlessly. The meticulous scholar, J. H. Hexter, in his Reappraisals of History, castigates historical relativism as a fad and insists on the “rudimentary distinction” between knowing something and knowing everything. But he omits all philosophic justification for this distinction. 

Undoubtedly this distinction must be maintained, if a human being is able to know anything at all. Make omniscience the prerequisite of partial knowledge, and partial knowledge vanishes. But Bultmann, like Hexter, offers no help: less help, in fact, for Bultmann lets the requirements of omniscience stand.

Then, finally, there is elsewhere an explicit connection made between Hegel and internal relations, along with the subsequent refutation of both:

That relations are internal, and especially that the truth is the whole, are themes hard to deny. Yet their implications are devastating. So long as you or I do not know the relationships which constitute the meaning of cat or self, we do not know the object in question. If we say that we know some of the relationships – e.g., a cat is not-a-dog and admit that we do not know other relationships – e.g., a cat is not-an-(animal we have never heard of before) – it follows that we cannot know how this unknown relationship may alter our view of the relationship we now say we know. The alteration could be considerable. Therefore we cannot know even one relationship without knowing all. Obviously we do not know all. Therefore we know nothing. 

This criticism is exceedingly disconcerting to an Hegelian, for its principle applies not merely to cats, dogs, and selves, but to the Absolute itself. The truth is the whole and the whole is the Absolute. But obviously we do not know the whole; we do not know the Absolute. In fact, not knowing the Absolute, we cannot know even that there is an Absolute. But how can Absolute Idealism be based on absolute ignorance? And ours is absolute ignorance, for we cannot know one thing without knowing all. (Christian Philosophy, pg. 153)

Now, I said in the above link that Van Til was more truly Hegelian than Clark, and the reason why has to do with internal relations. The first quote from that link provides the key:

Gordon was absolutely insistent that we did know some of the same things that God knew. If not, he insisted, it would be impossible for us to know any truth at all! That 2 plus 2 equals 4 is true, he felt. Thus he insisted that in and of itself it is true as a statement without the necessity of examining another proposition. He carefully insisted upon a propositional concept of truth while Van Til insisted upon the fact that to have truth in one's mind that mind must be built upon other propositions. The truthfulness or falsity demanded that the individual proposition be held in the midst of certain other basic propositions that must be consciously present in that mind in order to correctly know truth. Now, of course, God knows every proposition in the context of all other propositions for Van Til, and, therefore, the limited human mind never knows it the way God does. Van Til had an expression, of repeated: "true as far as it goes," meaning, of course, that for that mind which holds all propositions in a system, the more complete the system, the more full the truth. With growth in the knowledge of basic propositions, the further than mind had the truth. Van Til's concept is that for relative human beings, they can have all needful truth but never perceive it as God does with his infinite knowledge of everything that affects any proposition. He charged Clark, therefore, with denying the incomprehensibility of God and Clark charged him with agnosticism since he that that for him it was impossible to know anything as God did. Clark wanted an absolute even if it were only in the single proposition. (Gordon Clark: Personal Recollections, pgs. 103-104)

Note that for Van Til, it is because "God knows every proposition in the context of all other propositions" that "the limited human mind never knows it the way God does." Well, how does this follow? The idea that "God knows every proposition in the context of all other propositions" is true, but Van Tilians must go further by arguing that knowledge [which is univocal to God's] of even one proposition necessarily would imply knowledge of all propositions, which is why our knowledge must be analogical - for we aren't omniscient. But the only reason such would necessarily follow is if the doctrine of internal relations is true.

Recall that above, Clark defined "the theory of internal relations" as "the notion that everything is what it is because of its context... To know any one thing it would be necessary to know its context." This is precisely what Van Tilians argue univocal knowledge would entail. This is the only explanation of how "God knows every proposition in the context of all other propositions" can allegedly imply "the limited human mind never knows it the way God does."

On the contrary, that God necessarily knows everything in the context of everything else is what functions as the basis according to which we can be assured that the doctrine of internal relations is false. Who better than an omniscient God could know that partial knowledge is possible? Revelation is sufficient.

Friendly Fire

I recently had an email exchange about Scripturalism with a Reformed blogger. Early on in this exchange, I defined philosophic knowledge as “a belief about which one cannot be mistaken.” Now, I don’t really see what is so controversial about this. Of course, I acknowledge[d] that “knowledge” can refer to other concepts and that opinions can be useful, but this definition seems to me to be the most relevant for apologetic purposes insofar as a denial of it leads to skepticism (link).

Apparently, though, my correspondent was not very impressed, calling it, among other things, “grad-school gibberish,” “gawd-awful,” and, my personal favorite, “the dumbest damned thing I have ever read an adult write.” And this was just in response to a definition. Keep in mind this is all by a fellow presuppositionalist, and I don’t believe I had written anything provocative.

Lately, it seems as if straightforward, rational discussion of differences is getting harder to come by. In my recent studies about the Trinity and epistemology, I’ve honestly had a much easier time staying on topic with Roman Catholics than I’ve had with many Reformed Christians. I’m not sure why that is. It could just be a string of bad luck, so to speak.

In any case, there’s a fine line between defending your ideas and just being defensive. There has to be some room for debate. When you come across someone whose ideas are different than your own, if you immediately cut them off or cut them down, you may fool them, but you won’t fool yourself. And to those who know better, it just betrays a lack of confidence. 

I’m sure anyone reading this can fill in the appropriate qualifiers to the above, so maybe it’s best to end this post how all debates should [implicitly] begin: recognizing that even while we may take strong positions on certain issues, we all have a lot to learn.

UPDATE: I just watched this video by James White in which he also refers to Trinitarianism as almost “untouchable.” While I’ve made some critical comments on White’s own Trinitarian views in the past (link) - and ironically have been immediately dismissed by some Reformed Christians for it - I appreciate his willingness to take to task someone like William Lane Craig for unbelievably erroneous analogies of the Trinity to... a Greek myth about a three-headed dog???

Presuppositions of Van Til's TAG

I recently interacted at Pyromaniacs over an interesting post on presuppositionalism (link) to test a theory. In short, I was attempting to figure out whether the transcendental argument for the Christian God’s existence utilized by Van Til (link), Sye Bruggencate (link), and other “Van Tilian” apologists eventually requires an appeal to a self-authenticating divine revelation in order to be sound. Surprisingly, the two people who replied to me ended up agreeing with this. And this is not the first time this has happened (see posts 13, 15, and 16 here). Perhaps if the comment section wasn’t closed so quickly – and unfortunately, as I never got a chance to reply to one of the last posters who dismissively accused me of being a Unitarian and God-rejector while making elementary false dichotomies – there would have been others who would have stepped forward in agreement. The best thing to do in such situations occur is to shrug your shoulders and move on. And so, I’m going to reproduce what I consider to be the more relevant points I made from a few of the comments I left (refer to the first link for the full context):

I'm merely asking you to defend your proof. For it to be a proof, the Christian God must be the conclusion of an argument. The argument, or so I understand, is that because God is the precondition of proof (premise 1), and because proof is necessary (premise 2), God exists (conclusion). But a conclusion is only as true as its premises. I’m questioning how you came to know premise 1. 

This is, in rough form, the TAG I have in mind throughout this post.

The OP provides a practical argument for accepting first principles in general, but insofar as it intends to parallel the goal of Van Til, Sye, etc. - viz. to prove the Christian worldview in particular - I never understood why an atheist just couldn't respond: “Okay, so what is unique about your God (“the floor”) such that He (“it”) is the precondition for intelligibility, and why is this property necessary?” After all, in order to function as a “proof” for Christianity in particular, there must be something that distinguishes Christianity from infinitely many non-Christian worldviews.

The point of this comment is simple: to get the user of the TAG to identify what it is about the Christian God which makes him the precondition for proof or knowledge, and to understand why such a unique property is epistemologically necessary. Otherwise, an aforementioned premise 1 of the TAG is undercut, and the TAG itself will fail.

…a burden of proof is on you as well. For you are defending an alleged proof for [the Christian] God. It is not enough to just state that God alone is the very precondition for proof. That’s well and good, but that is, as it stands, itself an assertion in search of an argument. 

This is designed to explain why the user of the TAG is obligated to defend his premises. As I said in an above comment, as a proof, the conclusion of the TAG is only a good as its premises. If the premises are attacked, they need to be defended. Of course, as the user of the TAG will be presupposing God throughout his replies, it is to be expected that his defense will presuppose God as well. But an ontological presupposition is not necessarily an epistemological presupposition. The TAG clearly states that God is ontologically necessary for proof; the point is to find out if the TAG must also claim God (or, more precisely, God’s revelation) is an epistemological necessity as well. That is, it is just because God exists that proofs can allegedly be proffered - but will the substantiation of this eventually presuppose Scripture?

Now, if your answer to my question about premise 1 outlined above is just a deduction from Scripture, then I will ask you to prove Scripture. Eventually, you will hopefully see that something - God’s word, in fact - must be taken for granted without proof for the simple reason that we are not omniscient. Something must be self-authenticating, and whatever proposition[s] is or are taken as first principle[s] will be one’s alleged sufficient condition for knowledge. 

Now, both of the individuals I spoke to agreed that this is the case. And this would seem to be a point for Scripturalism, although on further reflection, I suppose there would still be some question as to whether Scripture itself has something to say about the hypothetical legitimacy of a separate, divinely sanctioned source of knowledge. In any case, though I could be wrong, I suspect the above agreement would be atypical if presented to most others who use “Van Til’s TAG.”

For example, take a popular proponent of this argument - Sye Bruggencate, who was mentioned in the post itself. I recently had the misfortune of witnessing Sye Bruggencate attempt to refute Scripturalism. Honestly, for a man whose apologetic method emphasizes logical argumentation, you would not expect to see Clark’s view so quickly dismissed with simplistic and common canards such as that empirical knowledge is necessary in order to even understand the Bible, let alone far-fetched objections like that one needs infallibilistic knowledge in order to obey a given command.

Then too I was initially presented with an argument in the comment section that the doctrine of the Trinity could function as a necessary and uniquely Christian tenet. But I argued that this line of reasoning too must, in the end, resort to Scripture:

Why one and three? Why not one and two or one and four? What about the personality of said God? Can all of His or their attributes really be deduced via reductio ad absurdems alone? 

And:

Again, for emphasis, the Trinity would be *an* explanation of unity and diversity, not necessarily the *only* explanation... unless we resort to a self-authenticating divine revelation.

And:

This is a good point too. By your own admission, then, belief in the Christian doctrine of the Trinity is only a necessary condition for belief in Christianity. That is, there are non-Christians who believe the Trinity. But that means the Trinity isn't a sufficiently unique doctrine.

To summarize, apart from Scripture, there does not appear to be any reason to prefer Trinitarianism to Binitarianism, a Quaternity, etc. And further, if non-Christians can believe in the doctrine of the Trinity, as my correspondent smartly pointed out, then the doctrine of the Trinity turns out to be not so uniquely Christian after all. Something more would be needed to explain why such people are inconsistent. What, if not Scripture? On the other hand, if Scripture, then:

I see no need to appeal to Trinitarianism at all as an intermediary step if we can and must appeal to Scripture anyway. Scripture itself is the unique doctrine of Christianity which contains the set of propositions which by definition distinguish the God whose word it is from all else.

That is, Van Til’s TAG - TAGs in general actually - serve an important purpose, but they are not the crux of Christian apologetics. They specify necessary but ultimately insufficient conditions for knowledge. Indeed, how we even know they are necessary is conditioned on what our sufficient condition[s] for knowledge has or have to say about them. To conclude with a reply I made to a friend who had a question about the initial comment I left:

The floor analogy is good if it is meant to depict our need for first principles in general. We all [must] operate on one or more presuppositions. The alternative - for us - is infinitism, and that leads to a never-ending justificatory process, which is why it is self-defeating. So far, so good. 

And yet, this argument for first principles is itself only a necessary condition for knowledge. It isn’t a sufficient condition. For example, the idea that first principles are necessary doesn’t specify a theory of language, logic, or metaphysics. It doesn’t provide us with the means by which we come to know truth. But I argue these are also necessary for knowledge - infallibilistic knowledge, anyway. In short, this [true] argument about the need for first principles is mutually dependent with other necessary truths. 

We aren’t omniscient. We will never be omniscient. So we have to take something for granted, and whatever this is cannot be proved. Rather, it will have to be self-authenticating. This isn’t a problem, because the idea “all propositions require proof” is suspect to the reply that this assertion itself needs to be proved. In my case, God’s word is my first principle, and I view it as a and the sufficient condition for knowledge - to emphasize, it is sufficient, not merely necessary, although it does account for subsidiary necessary conditions like the ones mentioned above. But if God’s word is self-authenticating, it cannot be “proved” per se.  

We can invoke its self-attestation and internal evidences - such as its ability to account for the necessary conditions for knowledge I mentioned above - for it, and these are excellent apologetic tools, but the idea that something is self-authenticating is antithetical to the idea it can be proved. There is nothing, for instance, which could be used to demonstrate that Philemon is canonical other than that it is God’s word. How do we know it is canonical? Well, because it is. There is no higher authority or epistemic criterion by which we can judge it to be God’s word. 

Again, this isn’t a problem, but it’s also not a proof. For it to be a proof, it would have to be a conclusion of an argument. But the only way that Philemon could be proved as God’s word would be if there were one system of truth about which we had comprehensive knowledge. We would need to be omniscient to know the truths of Philemon are necessary truths, because there is no simple reductio ad absurdem we can construct against one who rejects it as God’s word unlike, say, reductio ad absurdems we can construct against those who deny logic or first principles (as Frank did in his post).