But, I won't really be commenting on the actual critique itself as (1) I agree with the conclusion, but (2) think it has been already done by those like Anderson, Byron, Choi, Sudduth, and Welty, and (3) I find the use of all the symbollic logic in the critique rather unnecessary because the same thing has been done without it, as in (2), for instance. This should not take anything away from Bosse's series, and the comments aren't meant to undermine. Brian and I have known each other for a few years now. He was pushing his conclusion back then while I was still a right wing Van Tillian TAGster. I should say, though, that it's not so much a critique of Van Tillian presuppositional apologetics as it is a critique of one argument that some Van Tillians employ. For example, James Anderson would call himself a "Van Tillian," but he wouldn't be touched by this argument. Bosse agrees with this, though, and has stated: "If the Van Tillian removes his claim to “objective, certain proof,” then he is left with a very powerful apologetic indeed. Even though the proof does not meet the strict criteria for objective certainty, that does not mean it is wrong."
What I will do, instead, is comment on some of the discussions on Bosse's critique that is being had on the Puritan Board.
Basically, the claim made from some is that TAG still provides certainty.
Here's how some say the argument is certain:
"The argument is claimed to be objectively certain not because one does or does not hold to the conclusion as infallibly certain but because one should or has not right to deny the premises or the conclusion."
As it is, this is vague. What are "the premises" that one "should not doubt" or "does not have the right" to doubt? How is "should" and "the right to," to be understood here. Say that followers of Allah are taught that it is impious to doubt his word in the Koran, say that no mere human has the "right" to question Allah. Therefore, the Muslim can say they are philosophically and epistemically and objectively certain of it because Allah says that it is so and, furthermore, man "should" not, and does not have the "right" to, doubt Allah's word? Also, what does "infallibly certain" mean? Is there a "fallible certainty?" That is, it's likely to be true, but we could be wrong? So, the argument gives one "fallible certainty." And that means, "the argument's conclusion could be wrong." I think the opponant of the above claim would gladly accept this idea as it is consistent with his argument against strong modal TAG.
From the Christian's perspective, one "should" not disagree with God's word. But, the "conclusion" of TAG is that: "The Christian worldview alone is the necessary precondition required to make experience intelligible." Is this in the Bible? Is it God's word? Mere piety does not entail that we "should" not doubt something.
Furthermore, what is meant by "the Christian worldview," CWV? Has this been spelled out? It obviously isn't the claim that Abraham came from the land of Ur. Michael Butler even agrees with that.
One "should not" doubt the conclusion of TAG only if it's true. But, isn't that the debate? It thus looks like this idea of certainty requires one to accept the conclusion of TAG. Furthermore, mention is made of premises and conclusions. If the argument hasn't been made, then, though one may still believe the conclusion, one hasn't given any one any cogent reason to agree with it. So, "should" we agree with things we have no good or cogent reason to? Do we not have "the right" to doubt the conclusion of an argument which doesn't get to the conclusion, or cannot demonstrate the conclusion?
Lastly, the above smacks of deontological constraints, these constraints have fallen on hard times.
At any rate, since the above subjective considerations of certainty have been weighed and found wanting, let's look at what Greg Bahnsen has to say about certainty. In his article Pragmatism, Prejudice, And Presuppositionalism, PPP, Bahnsen lays out the conditions required for a worldview to provide certainty. Bahnsen says that "if epistemological certainty" is to be achieved, the worldview will need to: (a) avoid the ego-centric predicament, (b) prevent internal incoherence, and (c) be able to solve life's philosophical problems and be applied to the questions of life.
One can ask whether these three things that are said to be required for epistemic certainty are jointly necessary and sufficient. If so, if another worldview can do (a), (b), and (c), then we have a worldview that can provide epistemic certainty. This worldview will, per (c), provide preconditions for intelligibility, and if this is so, then the conclusion of TAG is, at best, not established, at worse, false.
Now, instead of the above quote, Bahnsen provides a quote which he thinks is the criteria for granting a position the honorific title of "epistemological certainty." He takes Frankfurt's stricture:
"The claim that a basis for doubt is inconceivable is justified whenever a denial of the claim would violate the conditions or presuppositions of rational inquiry...since inquiry is fundamentally an attempt to discriminate between what is to be accepted and what is to be rejected, nothing can rationally be conceived which involves denying the necessity for making these discriminations or undermining the possibility of making them." Bahnsen, PPP, p.292
So, say that there is a worldview that has all the features the TAGster says is necessary for intelligibility, but say this worldview has a quadune God rather than a triune one.
The TAGster must critique this worldview, If this worldview, call it Fristianity, can answer (a) - (c) above, then it is immune from Bahnsen's claims that it doesn't provide certainty. Furthermore, in PPP, p.285, Bahnsen says that all such worldviews must be approached internally.
Now, if the TAGster cannot show that Fristianity is internally incoherent, then it looks as if it can also provide these "preconditions." If so, the TAGster has failed to show that one has "no right" to doubt the conclusion. Since this worldview seems to also supply the preconditions for rational inquiry, then it meets Frankfurt's stricture. Furthermore, since all that is different is that it posits a 4-in-1 god instead of a 3-in-1 God, and the worldview has all the other features which as supposed to be necessary for rationality (but, as I said above, the TAgster needs to spell these out instead of saying, "it's a package deal"), and there is nothing I can see about the idea of 4 that is different from 3 for accounting for the one and many, etc., then, according to the TAGster's claim above, the "should not" and "have no right to" doubt this argument.
Now, what's the cash value here? Are we not supposed to be able to know that Christianity is true because of the above? I don't think so. Are we in trouble apologetically? I don't think so. For one, this Fristian move isn't open to anyone as a real option in the debate. Atheists and Muslims alike must reject their worldview to advance the Fristian position as their ability to provide preconditions of knowledge. Christianity still gives a worldview where preconditions for things like knowledge are to be had. So, we can stanrt and end with our worldview. If the only place the sinner can hide is by believing in a made up worldview, I'd say we're pretty good apologetically.
I actually find zero psychological or emotional problems admitting this. Ultimately, at the end of the day, I trust in the word of Christ. The mere logically possibility that another worldview also can provide for preconditions of knowledge does not bother me. I don't see anywhere where God promises that I'll have this kind of certainty. I am called to trust in His word. I don't question it. I should not, and do not have a right to, question it. No man should. I am rational in my belief, and I believe there are many good arguments and reasons for belief. All of these are, and should be, trumped by the testimony of God. That's my highest authority. I am psychologically certain of it. We don't have epistemic certainty because we cannot, as Dr. Sudduth argues, "preclude all possible reasons for doubting the truth of the proposition or belief in question" (emphasis added).
Though it may be offensive, I don't mean to be, those that fight against this seem to have a security blanket mentality. They seem to think that if there is a possibility that they could be wrong, then they cannot know whome they have believed in, and thus might as well become atheists. Talking to friends over the past months, they have admitted that this was the reason they fought against the above considerations.
Now, I admit the possibility that some day one could show the strong modal TAG. One could come up with an actual proof showing that 3-in-1 is necessary. This would be welcomed. At this point, though, we must be honest and admit that it hasn't been done. But I don’t think this is cause for concern for the Christian. Just like the kid on Mr. Mom who was asked to give up his woobie, he found out that the world wasn’t so scary as he had previously thought. He actually came out the better for it. Since I believe Christianity is true, no arguments will knock it down. But, though we’ll win the fight, we were never promised an easy battle. The magic bullet isn’t to be had, so get to training. In fact, after rejecting the strong modal version of TAG I have come to see just how strong the case for Christian theism really is!
Now, that we don’t have cogent arguments against all possible reasons to doubt that the CWV alone provides the necessary preconditions for knowledge does not entail that we should doubt Christianity. It is broadly logically possible that I am a butterfly dreaming that I am a man, should I therefore doubt that I am a man?
Indeed, it can be argued that there are norms of knowledge. Even the skeptic presupposes this in his doubts. So, to doubt presupposes things. I believe a case can be made that theism, esp. Christian theism, provides preconditions for norms of knowledge. The argument for that, though, could also be given by the Fristian. But I don’t let this possibility act as a reason to doubt Christianity. I have no reason to doubt it. Furthermore, it can be successfully argued that given something like Christian theism, we are warranted in believing that our cognitive faculties are successfully aimed at truth. Accepting beliefs like Naturalism and Evolution give us reasons to actually doubt that our cognitive faculties are reliable. Everyone knows that Christianity is the only game in town here. No one really believes that Fristianity is the case. Thus, even given Fristianity, there is no good reason to doubt the argument from the Christian, even if it is not epistemologically certain in the sense of being indubitable in the sense of refuting all possible reasons for doubt.
God made us. We know we’re sinners. Despite the attitudes of the apostate, even he suffers from guilt. The Christian does not doubt God’s word, because we have nowhere else to go, only He has the words of eternal life. The apologetical reasons for our claims are very strong, the atheological reasons against it are exactly as weak. The sinner does not have an excuse, if that’s what you’re wondering. To say he does presupposes that Jehovah will grant that one has an excuse for denying what he knows (God exists) even though there was a broadly logical possibility that another made up worldview could also provide the preconditions for knowledge. To say he does presupposes that what Paul meant by “know” in Romans 1 was “infallible knowledge of the Cartesian sort.” I have no excuse to not provide for my son even though there is a logical possibility that he is a craftily constructed robot from Alpha Centari who needs no care. How much more then does the unbeliever not have an excuse to not believe in God because of the wild possibility that a worldview just like it in all the essential areas, but has a 4-in-1 God rather than a trinity, can “provide for the preconditions of rationality?" So, that argument against denying the strong modal TAG is also found wanting.
Some would say that I make “possibility” more ultimate than God’s say-so. But, this (a) presupposes that God has indeed said “the CWV alone provides for the preconditions of intelligibility,” and (b) that, even if the Bible does say this, that I deny that it does. Denying that one can show that p, does not entail that one denies that p. My claim is that no one has shown this, but this does not entail anything problematic for the Christian apologist. This is simply a point of intellectual honesty, not of making possibility more ultimate than God's say-so. God's say-so is ultimate for me. When he tells me things, that's good enough for me. Indeed, if the Bible doesn't claim what the TAGster does, and the argument can be shown to be false (as it stands) then, actually, the Christian apologist's position and reputation are actually strengthened by dropping a bad argument. The argument can be amended, and then employed in a way not subject to a (as of yet) unanswerable critique.