There has been a recent spat of comments flowing out of a discussion generally related to TJH's post (link) and my response (link).
In particular, TJH, Keith, and an internet poster who has adopted the handle "John Calvin" (JC), have provided some comments worthy of further discussion.
TJH's first comments (link) require me to dig through the disarray of tomes that I call my library to try to locate my copy of the relevant book. I have not yet found time to do so. I'll try to do so soon, rather than rely on my memory.
Keith's comments (link) ask:
You say that science collectively says R. In reality, the truth is R’. This is trivial. Who wouldn’t agree with that? Are there people out there who think that science has always given us the truth? The whole idea behind science is that we keep modifying our “knowledge”.
Nevertheless, this makes more sense of Clark’s claim that science is “false.” Collectively, yes it probably is, but once again, if he’s concerned about epistemic certainty then he still can’t say its truly false, only probably false.
By the way, how does Clark know that the Bible says what he thinks it says given the uncertainty of language?
As to the first paragraph, that's an intermediate step of the argument, not the final point. I do think that virtually everyone would agree that the truth is R'. Nevertheless, evidentialism does not have the tools either to say with certainty that the truth is R', or even that R is close, far, or converging to R'. In other words, evidentialism is without an anchor. Evidentialism can convince us that the R of science is changing, but cannot tell us with certainty that it is approaching truth.
This does not mean that science is not useful, but that that science ALONE is not an epistemology of any value.
As to the second paragraph, all that is necessary for Clark to prevail is that we agree that evidentialism is an undesirable epistemology. Clark can easily demonstrate that Science collectively includes assertions that are contrary to the truth (for example, in the area of cosmology), but that is not based on evidentialism, but on Clark's own epistemology.
It's important to point out the evidentialism cannot only not show that R is not R' with certainty, but even that R is not R' with probability. There's no a priori way of assigning probabilities to the position. If one jumps out of evidentialism for a second, and presupposes that historical observations are a probable predictor of future events, then whatever you presuppose as that probability that historical observations will predict future events will correspond to the probability that Science is false. I'm not sure how helpful that would be.
As to the final question, Clark (like the Reformers) deduces from Scripture that the important things in Scripture are perspicuous.
TJH's second comments (link) follow on Keith's comments (above).
Also, that applies to theology as well. I’m sure that Clark’s theology underwent tweaks over the course of his life, and there was probably at least one false proposition left in there. Say it is certainly so. Then, by the same reasoning, can we not say that Clark’s theology was false?
(underscore substituted for italics in original)
Clark would agree that the entire body of Clarkian theology (even as it stood on his moment of death) undoubtedly contained some error or other, and consequently is not a suitable presuppositional basis. Clark would, therefore, agree that Scripture, not Clarkian theology, should be our epistemological starting point.
JC's comments (link) are lengthier, more vehement, and seem to reflect a personal stake in the debate, but are not remarkably different from Keith's.
 And of course you don’t know that my conclusion proves the absurdity of trying to argue like a Van Tillian, do you? It’s just your mere opinion, isn’t it?
 I see you *assert* that the sun’s heat is being spoken of literally, but you don’t know that, do you? Sure you can “presuppose it,” but whopp-dee-doo.
 Then I can prove God is a bird by “presupposing” that it is speaking literally? No. So, just “presupposing” anything willy-nilly is a bit unwise. And, of course you don’t even know that Scripture says “sun.” That word could be “oven,” and so your eyes are tricking you. How would you know otherwise?
 So, no free lunches. I want to know how the Clarkian doesn’t commit epistemological suicide every time he opens his mouth. Your saying “just grant me that I know what the Bible says,” sems like the evolutionist asking me to grant him that “life evolved from non-life just once,” and then he’ll show me how everything else follows. Like Tim said above, “of where one cannot speak, one should be
 You don’t know Clark existed, and you don’t know he had a high standard of knowledge, either. That’s another mere opinion. Also, you don’t know that you don’t need to know. So that was another opinion. A mere assertion. Why do you expect “Van Tillians” to grant you your unjustified opinions? Is it because it’s “absurd” to reason like us so you think you can pass assertions on as substantive answers and we won’t “get it” because we’re “absurd.”
 You don’t know that Clark existed, that’s right. But, you also don;t know that eh
should have been ordained because you don’t know if he was a man. You don;t even
know if you’re a man, how much more then do you not know that Clark is?
 I mean, you don’t even know that Scripturalism is the case! If all knowledge is either found in Scripture, or able to be deduced from Scripture, then since *that proposition* cannot be deduced from Scripture, you don’t know it! So, the Scripturalist can’t even know his own Scripturalist package. Thus it looks like you have in-house problems in your backyard that needf cleaning before you tell me to clean up my own backyard.
(all errors in original, numbering added for convenient reference)
As to , as I had previously stated (link), your conclusion demonstrates the absurdity of arguing like a Van Tillian. I'm not interested in proving that, or establishing to your satisfaction that I know it. If you don't see the absurdity of your previous argument (link), so be it. I think others can and will see the absurdity, but if not - I'll have to look for a more clear example. Perhaps the remainder of your present argument will provide such an example.
As to , the answer is that I do know that it is being spoken of literally; I have deduced that from Scripture.
As to , if you presuppose that God is a bird, it is your presupposition against mine. Yours are foolish presuppositions that will place you in the lake of fire, if you really hold to them. But I doubt you do. You only suggest such presuppositions to be argumentative.
As to  (cont'd), I do know that the word there is "sun," and you know it too. Your objection is not something you believe, but simply an attempt to be argumentative. I know otherwise by deduction from Scripture. If you would pay attention to the arguments presented previously (link), you would understand that.
As to , a better choice for comparison would have been the context of the recent PCA debate on justification. The elders have agreed that the WCF is Scriptural, and, thus, the debate centers around whether the FV doctrines are confessional. Nevertheless, yes, evolutionists are frequently trying to persuade people to accept their presupposition of Naturalism. If you do, you're not left with a lot of other choices besides evolution. As for epistemic suicide, Clark is not an evidentialist, and his epistemology is not evidentialism. His rebuttal of evidentialism, consequently, does not damage his epistemology. Your perception that it does appears to be a similar mistake to that made by Keith above.
As to , the questions of whether or not Clark existed or had a high standard for "knowledge" are not serious questions. If refusing to engage in puerile games is "taking a free pass," so be it. If the presentation of objections that are not one's own is all that Van Tillianism has to offer, I will let people decide for themselves whether it is worth anyone's time. Furthermore, "mere opinion" and "mere assertion" are not the only alternative to Clark's high standard of "knowledge." Your own assertions reflect your adoption of a false dichotomy.
As to , this argument relies on an implicit equivocation between the high standard of knowledge (absolute certainty) and ordinary knowledge. No one has suggested that we should act only on the basis of things for which we have absolute certainty, or that certainty is necessary in every aspect of life.
As to , despite the claims of many anti-Reformed apologists, Sola Scriptura is, in fact, a doctrine of Scripture. Here, at least, I think you go beyond any reasonable scope of Van Tilianism, if you deny that Sola Scriptura is a doctrine of Scripture. Perhaps, on the other hand, you simply either do not know what the doctrine is, or you are again equivocating between the high definition of knowledge and the ordinary definition of knowledge.
P.S. A response by JC with respect, primarily, to number 7 can be found here (link). In summation, JC falsely accused me of not understanding what Sola Scriptura is.
The only things we can know with the highest confidence are the things that God himself reveals. That is the reason behind the use of Scripture as the supreme judge. Once one has grasped that, the rest should fall into place, as long as one commits oneself to abandon consistent implicit equivocation over the words “know” and “knowledge.” So far, I don’t see the VT side doing that.