Van Til's concept of analogical knowledge is rooted in the distinction between archetypal and ectypal knowledge:
1) Archetypal knowledge - God's knowledge, which, for Van Til, includes an understanding of the relation of all facts to His person. This knowledge is an incommunicable attribute of God.
2) Ectypal knowledge - Knowledge communicated to man through God's condescension.
"The relation of God’s own self-knowledge to our knowledge of God used to be expressed by saying that the former was archetypal of the latter and the latter ectypal of the former. Our knowledge of God is the imprint of the knowledge God has of himself but always on a creaturely level and in a creaturely way. The knowledge of God present in his creatures is only a weak likeness, a finite, limited sketch, of the absolute self-consciousness of God accomodated to the capacities of the human or creaturely consciousness. But however great the distance is, the source (principium essendi) of our knowledge of God is solely God himself, the God who reveals himself freely, self-consciously, and genuinely” (Bavinck, RD1, 212)."
“Alongside of the archetypal knowledge of God, found in himself, there is also an ectypal knowledge of Him, given to man by revelation. The latter is related to the former as a copy to the original, and therefore does not possess the same measure of clearness and perfection. All our knowledge of God is derived from His self-revelation in nature and in Scripture. Consequently, our knowledge of God is on the one hand ectypal and analogical, but on the other hand also true and accurate, since it is a copy of the archetypal knowledge which God has of himself” (Berkhof, ST, 35)."
This distinction is the key to understanding what Van Til means by analogical knowledge, and how it differs from that proposed by Aquinas. Van Til believed that the Triune nature of the God of the Bible provides the philosohpical key for understanding how the diversity of experience can relate to a unified ground. The key is, for Van Til, this Triune nature is incomprehensible. Therefore, God's archetypal knowledge is limited to Himself.
Since God's Triune nature is incomprehensible, the nature of the relation of god's knowledge to His incomprehensible nature is also incomprehensible. Mankind can therefore not understand how God's knowledge relates to His knowledge of Himself. There is a solution to the philosophical problem of how the diversity of experience relates to a unified ground, but mankind cannot understand this solution.
One of the most important ways in which Clarkian epistemology is incommensurable with Van Tillian epistemology has to do with the ramficiations their religious metaphysics has to do with their epistemology. Whether or not Clark accepted the archetypal/ectypal distinction with respect to epistemology is ultimately irrelevant to a reconciliation between the two views, because Clark rejects the notion that God's Triune nature is incomprehensible in his book "The Trinity." We have seen that it is precisely because Van Til saw God's Triune nature as incomprehensible, that he argued that the relation of God's knowledge to knowledge of His nature, and of the relation of His knowledgbe to this nature, is itself incomprehensible.
Van Til therefore saw God's knowledge as qualitatively different from our own. Clark, of course, denied that we know as much of God, and he would deny that we know any fact within the context of all other facts the way God did. But he did not believe that this meant that God's knowledge was qualiltatively different from ours, as Van Til's religious metaphysics necessitates.
Did Clark accept the archetypal/ectypal distinction with respect to knowledge? It depends what is meant by this. If all is meant by this is that only God understands the way all facts relate to Him, or that only God knows how each fact relates to all other facts, he certainly does not find this objectionable:
William James, in his A Pluralistic Universe stressed the disconnectedness of things. Wholes are to be explained by parts and not parts by wholes, he said; one group of events, though interrelated among themselves, may be unrelated to another group; there is no dominating unity – however much may be reported as present at any effective center of consciousness, something else is self-governed, absent, and unreduced to unity. In one place James denied the need of answering a question that many others have thought as important as it is difficult: “Not why evil should exist at all, but how we can lessen the actual amount of it, is the sole question we need there to consider.” Of course, if a question is literally meaningless (such as, why is music oblong?) it is really not a question at all and does not need to be answered. But if a question is not senseless, by what right can a philosophy rule it out of court? Even if it were quite trivial, it should find its place and its answer in some minor subdivision of the truth. Then, too, one might ask how James discovered that some groups of events are unrelated to other groups? Or, more exactly, since he allowed “external” relations and denied only “internal” relations, one might ask how James could discover that something is absent from and unreduced to unity by every effective center of consciousness? In other words, did James have a valid argument for the conclusion that there is no Omniscient Mind whose thought is systematic truth? He may then be caught on the horns of the dilemma he tried to escape. Irrational chaos and Hegelian monism were equally repellent to him. He wanted to find a middle ground. But perhaps there is no escape from irrational chaos except, not exactly Hegelian monism, but a logical completeness of some sort. It would be surprising, would it not, if social stability could be based on incoherence, or even large-scale disconnectedness?
At any rate, the suspicion that the introductory questions are all related and that an answer to any one of them affects the answer to every other would accord with the theistic belief in divine omniscience. The discouragement, the reflection, the suspicion of the previous pages do not prove or demonstrate the existence of an omniscient God; but if there is such a God, we may infer that all problems and all solutions fit one another like pieces of a marvelous mosaic. The macrocosmic world with its microcosmic but thoughtful inhabitant will not be a fortuitous aggregation of unrelated elements. Instead of a series of disconnected propositions, truth will be a rational system, a logically-ordered series, somewhat like geometry with its theorems and axioms, its implications and presuppositions. Each part will derive its significance from the whole. Christianity therefore has, or, one may even say, Christianity is a comprehensive view of all things: It takes the world, both material and spiritual, to be an ordered system. Consequently, if Christianity is to be defended against the objections of other philosophies, the only adequate method will be comprehensive. While it is of great importance to defend particular points of special interest, these specific defenses will be insufficient. In addition to these details, there is also needed a picture of the whole into which they fit. This comprehensive apologia is seen all the more clearly to be necessary as the contrasting theories are more carefully considered. The naturalistic philosophy that engulfs the modern mind is not a repudiation of one or two items of the Christian faith leaving the remainder untouched; it is not a philosophy that is satisfied to deny miracles while approving or at least not disapproving of Christian moral standards; on the contrary, both Christianity and naturalism demand all or nothing: Compromise is impossible. At least this will be true if the answer of any one question is integral with the answers of every other. Each system proposes to interpret all the fact; each system subscribes to the principle that this is one world. A universe, even James’ pluralistic universe, cannot exist half-theistic and half-atheistic. Politics, science, and epistemology must all be one or the other.
The hypothesis of divine omniscience, the emphasis on the systematic unity of all truths, and the supposition that a particular truth derives its meaning or significance from the system as a whole does not imply that a man must know everything in order to know anything. It might at first seem to; and Plato, who faced the same difficulty, tried to provide for two kinds of knowing so that in one sense a man might know everything and in another sense not know and learn a particular truth. At the moment, let an illustration suffice. To appreciate an intricate and beautiful mosaic, we must see it as a whole; and the parts are properly explained only in terms of the whole; but it does not follow that a perception of the pieces and some fragmentary information is impossible without full appreciation. Or to pass from illustration to reality: A child in first grade learns that two plus two is four. This arithmetical proposition is true, and the greatest mathematician cannot disprove it. But the mathematician sees this truth in relation to a science of numbers he understands how this sum contributes to phases of mathematics that the child does not dream of and may never learn; he recognizes that the significance of the proposition depends on its place in the system. But the child in school knows that two and two are four, and this that that child knows is true. Omniscience, even higher mathematics, is not a prerequisite for first grade. (A Christian View of Men and Things, 2005, pgs. 22-24)
But he certainly did not accept Van Til's development of the distinction with respect to his understanding of the incomprehensibility of God, and the ramifications of this incomprehensibility for epistemology. Indeed, he explicitly rejects such a notion in a chapter on Bavinck and Van Til in his book on the Trinity:
Near the beginning of this book Bavinck declares "...the idea that the believer would be able to understand and comprehend intellectually the revelaed mysteries is equally unscriptural. On the contrary, the truth which God has revealed concerning himself in Scripture far surpasses human conception and comprehension"(p. 13). Taken at face value these words seem to contradict 1 Corinthians 2:7-16 where "none of the rulers of this age has understood," but where "we have the mind of Christ." In Ephesians 3:3 "God made known to me the mystery...and you can understand my insight into the mystery of Christ." In the following verses this mystery is to be made known either to the Ephesians or to the rulers in heavenly places. In particular, since Bavinck expressly says that we cannot understand Scripture, one must insist the "all Scripture...is profitable for doctrine...that the man of God may be thoroughly furnished for every good work." If we cannot understand or conceive what God tells us to do, of what use is the revelation?
Admittedly Bavinck spends the next several pages arguing that God can be known. The difficulty is his neglect to define incomprehensibility so as to distinguish it from knowledge. Does incomprehensibility mean simply that we do not know everything that god knows? Certainly other Dutch theologians have rejected suchan idea as a merely "quantitative" distinction. They want an all-inclusive qualitative distinction, refusing, however, to mention the quality, and to define quality in the first place. Bavinck makes certain assertions: God can be apprehended; he cannot be comprehended. There is a "knowledge" but no "comprehension" of God(pp. 32, 33). Perhaps we should understand a following sentence as his explanation: "we fully agree with Kant that our knowledge is confined to the realm of experience"(p. 36). This is incredible! The reason Kant denied any knowledge of God was that he confined knowledge to sensory contnet. The mind imposed space, time, and causality on the chaotic sensations. God and the Ding an sich were totally unknowable because they had no sensory content. How can Bavinck, if a Christian, "fully agree" with Kant in limiting knowledge to experience? Does he make God unknowable? Or does he hold that God is an object of sensation?
Bavinck (op. cit., p. 41) asserts that "All those who teach God's knowability are willing to admit that this knowledge is of a peculiar and very limited character." Such a statement is too universal. Presumably all who teach God's knowability agree that its extent is very limited; but not all agree that this knowledge is peculiar. Like all other knowledge, our knowledge of God consists of certain propositions or truth. No doubt it is true that "that which God reveals of himself...is so rich and deep [presumably Bavinck means extensiv eand complicated] that it can never be fully known by any human individual." but this is not because the knowledge of God is a peculiar and different kind of knowledge: It is because life is too short to gain an understanding of the Bible. The defect lies in the shortness of human life, and often in the mediocrity of the man, not in the understandability of the revelation, for all Scripture is profitable for doctrine. Bavinck tries to support his position by an inverted comparison. He says, "In many respects we do not even understand the universe of created beings,...How then should we be able to understand the revelation of God?" This is inverted because as Hume and Einstein said, and as the history of science so clearly shows, we can never discover even a single law of nature. The laws of physics are constantly changing. The Bible remains fixed. Hence it is possible and easier to know God than to know how nature works(Clark, pp. 79-81, "The Trinity").