Adult Sunday School No TAG Backs

Amen.

Let's pray.

Dear Heavenly Father, thank you for this morning and I pray that you would help us as we consider your word and your existence and all the things that you've given us in Jesus' name, amen. All right, so Josh and Brian are out this morning and I'm teaching Sunday school so we're going to take a break at least for one week from this book, possibly also next week because I think I'll be teaching Sunday school then too, but may, even if I teach, I may still go through the book so have the chapter ready regardless.

The Transcendental Argument for God and the Question of Other Religions

All right, let me pass these out. All right, so just like last time where we went through a paper on the, on epistemic certainty about what we can be certain about, whether or not we can know what the Bible says is true 100 or whether or not we have to just know some degree of confidence.

So we talked about what kinds of things we could be certain about, what kind of things we can have a relative certainty about, what kind of, and different categories of certainty so that we're not going around saying, yeah, I'm mostly sure that God is real or I'm mostly sure that Christ rose from the dead, but that we can actually say that with a real confidence.

Now, we only addressed the fact that we can have certainty. We didn't really say, you know, how do you go about making, describing that foundation of certainty beyond just, you know, the fact that God gives us revelation and that we can be certain.

You know, why should we believe that God exists, for example? So that's a very standard question that people want to answer. Does God exist and how can we know and how certain can we be? Is it just something that's a matter of relative certainty and specifically, does the Christian God exist?

Now, if you're familiar with the different camps of apologetics, there's one camp called presuppositionalism, which I would place myself in that camp and say that this is a proper way of thinking about God's existence and our relationship to Him and the way that His existence should be argued for.

And we'll talk a little bit about that. The main, I don't want to say the main argument, but I guess the main framework for making an argument, it's called, in presuppositionalism, it's called TAG, which stands for the Transcendental Argument for God.

So the way that works is there's some transcendental, like beauty or morality, something that, you know, everyone agrees with or at least the person you're talking to agrees really exists. And then you explain that in their worldview, they can't account for how that exists, but in the Christian worldview, you can because God is the source of beauty or morality or truth, et cetera.

So if you're looking at the title of this paper, that's what TAG refers to. It refers to that transcendental argument for God that if truth is real, if beauty's real, if logic's real, if morality is real, then only the Christian God can account for that, so the Christian God is true.

Now there is a very common response to that, which is what this paper is getting at. A very common response to this is, well, can't any religion make pretty much the same argument? Can't you, as a Muslim, say, oh, you know, you believe truth is real, and so you need the Islamic God to account for that?

You know, what really makes Christianity special among other religions to be able to make this argument not other religions? What is that? So that's where this paper's coming from. This is what I was wrestling with at the time, trying to be able to articulate and understand.

So we're going to walk through this just like we did before, you know. I'll read a couple of sentences and then explain some of the background of why, you know, I said things the way I said them and so on.

Let's go ahead and start this off. If you don't, I don't think somebody walked in, if anybody needs a paper, they're right there on the, on that corner. All right, introduction. In 1985, at the University of California in Irvine, Christian apologist Greg Bonson and atheist Gordon Stein participated in what is known by many as the Great Debate.

To this day, it remains a mandatory, it remains a mandatory reading or listening for budding Christian apologists, especially of the Reformed variety. Has anybody, who here has actually seen this debate?

Okay, we got, who has seen this debate? It's on YouTube, you can find it. Well, the video's not on YouTube, but the audio is, right? Only a few people here have listened to it. This is really good stuff.

You should listen to it. It's really, it will not be a waste of time. I do not usually watch or listen to things multiple times, you know, even really good books, I usually don't read multiple times. I've probably listened to this debate maybe four or five times.

So it's, it's worthwhile. Yeah, and if you've never heard of Bonson, he was a student of Van Til, if you've never heard of Van Til, he's the guy that most people are thinking of when they're talking about presuppositionalism.

And I get that there's lots of words I'm using here that aren't fully defined, but feel free to raise your hand and ask if you want, if you want more definitions for any of these things.

All right.

The overwhelming consensus declares that Bonson destroyed the objections of his opponent through the use of the transcendental argument for God tag, as pioneered by Cornelius Van Til. Yeah, if you, if you listen to the debate, what happens is, I think, yeah, Bonson gives the opening statement, because that's what you're supposed to do.

If you're making the positive case, you get to make the opening statement. And so he makes this transcendental argument for God. And then Stein gives, gets up and gives his opening statement. Now the opening statement in a debate for the, for the negative side is not supposed to interact with the arguments presented on the positive side.

So it's kind of expected that he wouldn't necessarily be arguing with everything Bonson.

Says.

But he goes through and he, he lists all the different arguments for the existence of God. You know, the first, the, the unmoved mover, the ontological argument, the, you know, and he just goes through a whole bunch of these and explains why none of them are quite right.

But he doesn't, he doesn't end up address, he doesn't end up addressing the transcendental argument. And so Bonson, in his first response, gets up and says, he says, or in his, not the first response, in his, in the cross-examination, he says, did you, did you, in any of your arguments that you talked about, did you address the transcendental argument for the existence of God?

And he said, no. So Bonson, when he gets up and gives his response after the cross-examination, he says, ladies and gentlemen, my opponent has not yet entered the debate. So we're like halfway through and he says he hasn't even begun to contend with any of my arguments.

So anyway, it's a, yeah, it's pretty exciting listening from a, especially from a Christian perspective because you're like, yeah, our side. All right. However, perhaps the most unsettling exchange from a Christian perspective occurred during the time of audience-sourced questions.

Having been asked how he knew that Christianity is the only true religion, given that there are so many in the world, Bonson first replied that he did not have time to explain this, but that his original opening statement had such an explanation.

So yeah, this questioner asked, okay, so you said that, you know, atheism's not true, but you said that only Christianity is true. How do we know about all the other religions? How do you know that none of the other religions are true because there's thousands that you've not addressed and you don't even know about?

How can you know that those are not true? And that is a much harder question than why is atheism false, at least in my opinion. I think a lot of people think of atheism as being this very robust or very serious position that must be seriously contended with, and honestly, it's one of the most bankrupt philosophically positions that you could have.

The idea that things came from nothing, the idea that, you know, we should act in a way that is moral, even though there's no source of morality, is very, very philosophically bankrupt. It's one of the weakest positions that someone could hold.

It doesn't matter how many very smart scientists hold it. It's really one of the weakest positions that could be held. And dealing with some of these other questions are in a way a lot harder to do. All right, at this point, he continued, so his first statement was basically, well, I said some stuff in the opening statement, but I don't have time to go into it in detail, and then he responds.

What I did say, however, was that if I can find it here that I have not found the non-Christian religions to be philosophically defensible, each of them being internally incoherent or undermining human reason and experience.

So he's saying, you know, if they don't have a God that can account for, you know, the morality that we have or the truth that we have, then it's incoherent. Now, but he says this in a way where of all the ones he's examined, right, and so that leaves a little hole, but what about, it leaves a large hole actually, what about all the ones you haven't examined?

How do you know that there isn't one out there that is going to be defensible? How can you, how can you assert that? So that's what I want to deal with here. What is, if Bonson had more time, what might he have said, you know, beyond just I haven't found one that's defensible?

Okay, so if this is to be taken as a complete summation of the argument the Christian can make against every form of non-Christian belief, it is problematic to say the least. A presuppositional apologetic cannot rest on man's examination and refutation of a handful of major religions.

It must conclusively refute every possible expression of unbelief. Yeah, and since we're going to use this term so much here probably, I should try to explain what presuppositionalism is. It is called presuppositionalism, once again, like a lot of labels, it was termed by outsiders.

You know, Lutherans were called Lutherans by outsiders. They didn't call themselves Lutherans, right? So it's one of those things. So a lot of times a presuppositional apologist will be pointing out that someone is presuming, presupposing something to be true and attacks those presuppositions rather than dealing with the surface-level objections that exist, right?

They try to get at the presuppositions often, and that's why it's usually called presuppositionalism,.

Right?

So someone might say, you know, why is God so evil in the Bible? You know, he kills children, there's all kinds of genocide that happens. And a lot of Christian apologists will sit there and try to defend God and say, well, actually, it's good.

You know, you ever listen to William Lane Craig talk about this? He'll say, actually, it was good for those children because otherwise they would have grown up and been held accountable for their sins, and they would have gone to hell if they had grown to be adults.

But because God killed them at early ages, before the age of accountability, they get a free pass to heaven. You know, all this unbiblical theology. And then on top of that, just not really dealing with what matters, but just trying to defend God as though he needs that kind of defense from, yeah, this ridiculous claim.

So the presupposition behind there is that morality is a real thing, and my sense of morality is true. And so the presuppositionalist, rather than, you know, immediately trying to defend God like that and say why this was a good thing, would probably, will tend to, and doesn't have to, but will tend to address the presupposition, well, you believe morality is true.

On what basis is something right or wrong? On what basis is something good or evil? And let's talk about that before we even begin to address whether or not God was doing something right or wrong. Because if the foundation is God, well, of course, his actions are definitionally right.

And if it's something else, why would that be a reasonable foundation for right and wrong? So that's why it's called presuppositionalism.

Yes.

Yeah, absolutely. But the presuppositionalist is going to recognize that while those are proofs of God, really everything is in a way a proof of God. The heavens declare his handiwork. All these things are proofs of God.

So why is it that some people go to something rather than other things? Because they think they're going to be more persuasive. The presuppositional apologist realizes that Romans 1 says that people are suppressing the truth in their unrighteousness.

And so it's not just, oh, they need some more persuasive evidence. Or if I give someone prophecies, there's a good chance that they will just reject that too. And so it's not, if the presuppositionalist either goes to natural evidences or they go to prophecies, they wouldn't be doing it the way the other person is, where they're going to say that these are sufficient proofs that even apart from a work of the Holy Spirit you could come to accept.

They're going to be presenting these things as God's word and with an understanding that this person is going to reject them because of that suppression of truth unless the Holy Spirit is doing some work in them.

So there's a different way in which the presuppositionalist is speaking of these things. And it's interesting, when I first encountered presuppositionalism, I was struggling with this because I was interacting with atheists, and I would make arguments largely from prophecies.

I would say, well, here are some prophecies that were filled, but I know that you could just say, oh, well, that was just a chance that that one got fulfilled, or this is just, you know. There's just all kinds of ways of rejecting it if you're hell-bent on rejecting it, right?

And ultimately something else is needed. And so, yeah, the presuppositionalists will often go, sometimes they'll talk about that, but they recognize that there's deeper foundations, you know, what makes events meaningful.

And that is that there's a God who gives them meaning. You know, we don't live in an existentialist world where things only have meaning after the fact, right? They exist, and then we attribute meaning to them.

They have meaning before the fact, and that's what makes prophecy meaningful and the events that come from it.

All right.

All right. So this is not to say a superior counter-argument hasn't been proposed. In fact, it is not even to say that Bonson did not have a superior, i .e., more complete argument up his sleeve. Yeah, and I footnote there where Bonson wrote more extensively about these things.

You know, Bonson knew a better answer to this. He just didn't have time. And there's a recent work on the Trinity and Christian paradox, B. A. Bosserman provides a brief one-paragraph response to the objection that Tagg does not handle every opposing worldview.

This response includes some of the following two-part, includes the following two-part counter-argument. So this is kind of my issue, is, like, I've read a lot on this topic, and I always find that when people address some of the meatiest issues, they just do it in a sentence or two.

I'm like, oh, man, I want a whole book just on this. So this is what I'm trying to do. I'm trying to expand these slots just a little here.

Okay.

First, Vantill locates the destructive feature of unbelieving thought in its reliance on abstractions and not on any particular abstraction idol that one advocates. So in other words, he's saying, you know, Vantill, the guy that a lot of people are thinking of when they're thinking of presuppositionalism, he's arguing about abstractions.

He's arguing about things that apply to every other religion, not arguing about things that just apply to the one religion he's interacting with. In this case, until and unless one is able to demonstrate how fallen man could reason without abstract principles or solve the one and many problem with them, the Christian apologist has every reason to believe that his critique is conclusive.

Second, the unbeliever's romantic hope that somehow, some way, autonomous man might be able to make sense of the universe apart from God represents a reliance on the irrationalist notion of open-ended chance that Vantill has already proven self-destructive.

So there's a lot right there in that paragraph, and this is, okay, so, yeah, my objective in the rest of this is just two things, right? It's one, help Bonson answer that question, and then two, expand what Bosserman said as an answer to that question.

All right.

So this is exactly the two-part counterargument that must be given, each handling a different level of objection. However, Bosserman's few sentences are brief, and much more could be said. The purpose of this essay is both to further elaborate upon the significance of the previously mentioned objection to tag, and to expand upon this two-part counterargument.

Given that this particular objection has often been levied by claiming that other worldviews could also use tag in their defense, this essay is entitled No Tagbacks. You know, if you're playing tag with kids, that's what they yell is no tagbacks if you make sure I tag them right back.

All right.

Fideism, Axioms, and the Claim to Certainty

So let me restate the problem using a theological term called fideism. Who knows what fideism is? I was telling somebody here about fideism recently, I thought, so one person should.

Know.

Yes?

Faith in faith.

Yeah.

I think that's a good way of saying it, faith in faith. So a fideist says that you can be consistent in your belief, but you can't know for sure whether or not it's true.

Right?

And so if you've ever, a lot of people think of faith as being that leap of faith that you take, and then you're trusting God, where you don't have any evidence that you should be trusting God. Okay, that's fideism.

Right?

Fideism, you don't know whether or not you should trust God, you just do. But the way the Bible describes the certainty that we should have in God is one where we actually know. It's not just we don't know whether we should know and we pretend that we know.

No, we actually do know.

Right?

So we shouldn't be fideists. The problem of the potential existence of other worldviews that could substitute Christian theism as the only foundation for intelligibility is one of fideism. That is, if there could be some non-Christian worldview that provides the preconditions for intelligibility, then our faith is only certain to the extent which we are unaware of the existence of any such worldview.

One can only be certain beyond the leap of faith that it takes to enter the worldview of Christianity, accepting without proof that no other consistent worldview exists. However, that leap of faith cannot ever be evaluated as correct or incorrect.

So if you say, okay, well, Christianity is consistent and I've never found another religion that's consistent, so I'll just trust this one, even though there may be another religion out there that's also true.

Right?

Okay.

That would be fideism because you don't know for certain that Christianity is the only true religion.

All right?

In fact, Van Til was often labeled a fideist. So if you ever, yeah, there's a lot of controversy around Van Til, and honestly, even in our circles, Reformed Baptist circles, he's not exactly a popular figure.

He's a pretty controversial figure. And a lot of people will call him a fideist because of some of the arguments that he would.

Make.

Although most typically for other causes, such as that of his circular reasoning, which we will not address in this paper. So because Van Til is arguing for the existence of God, and that's a foundational truth, you see, is the ultimate authority.

Arguments for ultimate authorities have to be, by nature, circular, right? If you're going to say God is true because of these other principles that I'm building on top of, well, what's at the foundation of your argument?

If it's not God and you're arguing from something else, then you're not arguing for God as an ultimate authority. In fact, by your argument, you're undermining God as the ultimate authority. And so he would say that the only way you can argue for the existence of God is by presupposing the existence of God.

And people would see that circularity, and they would say, well, he's a fideist because he doesn't believe he can really know that God is real. He's just assuming it and then trying to prove it from that assumption.

There's more going on with it than that. First of all, once again, anybody has an ultimate authority. Whether they make it evident or not, it has to be circular. There's no way of arguing for an ultimate authority by appealing to something else that is not the ultimate authority because then you've undermined your ultimate authority with something that's more foundational to you.

And the reason that you can do this is because of what's known in the transcendental argument as the impossibility of the contrary. So he's not saying just that God is true because God is true, although that is the case.

He is our foundation for believing in his existence. However, he is also saying that because it is impossible for there to be any other true religion, then you can know it's true. So for example, and I'm trying to think if I get in here.

Oh, yeah, I do. So I'll save that. Yeah, let's just keep going. Regardless of whether his argument is to be correctly termed fideist, he did not consider himself to be presenting a fideist argument. Let me see if I can get a pencil to correct my, yeah, he did not consider himself to be presenting a fideist argument.

Van Til believed he was offering a certain proof and thus is undeserving of the aforementioned.

Label.

His goal was not to merely presuppose the truth of Christian theism, but from this presupposition prove the truth of Christian theism. So he really did believe that it could be proven. Now a lot of people, this is very common in Christian circles to talk about God and people will really readily concede that, yeah, you can't really prove that it's true, you can't really prove that God is true, you can't really prove Christianity is true.

It's not the case. There is a proof and a certain proof. And people don't like it, but the proof is, the foundation of that proof is God himself. All right, this defense against the label of fideism may not be readily received, but it can be further vindicated through a legitimate example of presuppositional fideism.

So let me give you an example of what real fideism looks like. There is another guy named Gordon Clark at that time who people also labeled presuppositionalist even though his arguments were a bit different.

And he really was, I would call his beliefs fideist. Gordon Clark, another apologist, under the broad umbrella of presuppositionalism, referred to revelation as an indemonstrable axiom. So it can't be demonstrated and it's an axiom, right?

You know how axioms work in mathematics, so axioms are the most fundamental things that can't be proven, right? And so you start off with some axioms, you know like that one plus one is two, the axiom of addition, and you build whole branches of mathematics out of that.

Because from that you can get multiplication, then you can get exponentiation, and then you can do all kinds of neat things with just addition, just building off of that. Now in math, you don't have to, axioms are not like true or false just by their nature.

You simply accept them and assume them. So for example, one axiom in Euclidean geometry is that parallel lines never intersect, okay? You just assume that that's true, that they never intersect. And you have a whole, you know, that's the typical branch of geometry that you're working with when you, you know, go to school and you study geometry.

However, there's also Riemannian geometry where they throw out that axiom. They say, actually, what if we don't know that parallel lines don't at some point intersect? And you have a whole different branch of mathematics that you can build where it's not, you know, a matter of truth or false.

It's just if these axioms are true, if we start with these starting points, what is true from that, right? So this is how axioms work. You can think of other things, right, like, well, no, that's probably not a good example.

But I was thinking of imaginary numbers, but I don't think that really works as an axiom. Anyway, axioms are not something that are in and of themselves true or false. They're things that are assumed and then you, all the truth that you build off of that is conditioned on these initial axioms being true.

Okay, so he, Gordon Clark, called, referred to Revelation, referred to the existence of God even, as an indemonstrable axiom. So it's not something that can actually be proven. It can only be assumed like an axiom.

Axioms in mathematics are starting points from which are derived other ideas, theorems. In Clark's view, Revelation is an axiom in that we start from Revelation and develop our other beliefs from that starting point.

This is not objectionable. However, an axiom is arbitrary. So arbitrary meaning that you pick it, you arbitrate, and you decide which axioms you're going to take with you in your branch of mathematics.

In math, you may add an axiom or remove an axiom and create an entirely new field of mathematics, hence the existence of both Euclidean and Riemannian geometry. The opposing branches of geometry, each determined by rejecting or accepting the axiom, the parallel lines intersect.

Clark may not have explicitly had the arbitrariness of axioms in mind when he used the term, however, the idea must have been there implicitly given that he speaks of axioms as indemonstrable, a term that accords with the arbitrariness of mathematical starting points.

If axioms are starting points, many sets of starting points lead to consistent and valid branches of mathematics. One cannot be demonstrated as true over any other. So it's not like Euclidean geometry is true and Riemannian geometry is false, right?

They just are what they are. Clark, let's see, the axioms cannot be proved. They can only be assumed. In describing revelation as an indemonstrable axiom, Clark allows for the possibility that other consistent sets of axioms exist.

However, in the Vantillian system, revelation is not an axiom but merely a presupposition. So there's a difference between an axiom and a presupposition. Those are not synonyms for each other because a presupposition can be proven even if it is the starting place, the foundational truth.

Thus, it is free to be both a starting point and the result of proof. So it's both. It's not just the starting point like an axiom would be. As stated previously, Vantill believed that he could prove the truth of Christianity by starting from the foundation of Christianity.

This is entirely unlike the fideistic idea that we can do nothing to demonstrate our starting point over all other potential starting points. However, we must still demonstrate that tag can be used to defeat all potential world.

Views.

Otherwise, we can only stand with Clark and defend a consistent system against any inconsistent system that arises, never having certainty that no other consistent system exists. It will not suffice to show the impossibility of the contrary, as Vantill abstractly termed the non-Christian worldview, if the contrary is only one instance of unbelief.

So when he said you show the impossibility of the contrary, he's not saying show the impossibility of Hinduism or show the impossibility of Islam. He's saying show the impossibility of non-Christian theism, the antithesis.

There's Christian theism, that's one worldview, and there's non-Christian theism, that's the other worldview. There are only two worldviews. Of course, you could consider thousands of worldviews. Everybody's got their own worldview in a way, or Hinduism is a different worldview than Buddhism, et cetera.

But at the end of the day, Vantill's only considering two, which is Christian theism and non-Christian theism. One who demonstrates Hinduism false by virtue of its polytheism has not demonstrated Islam false because Islam does not suffer from the same malady.

The problem here should be clear, right? So if you show that one religion's false, how are you showing that all the others are.

False?

And there's a way in which that's true, but it's not because, oh, okay, we showed that polytheism's not true. That means that Islam is not true. Well, Islam isn't polytheistic, okay? That's not a problem in Islam.

So how do you address all religions and not just the one you're dealing with? The issue has led some, mostly secular philosophers, to call for modest transcendental arguments. So this is a category that people have proposed, modest transcendental arguments.

Let's not say that we can address all other worldviews. Let's just say we can address only, you know, the one we're talking to, or categories of worldviews. A modest transcendental argument being one that does not argue for the truth of the contended position.

So we're not trying to say that Christianity is true, we're just trying to say that it's consistent and not necessarily false, right? But is rather content only to demonstrate that the position is not necessarily false.

For Christians who are commanded to proclaim the Lord with certainty, such a concession is not acceptable. Having seen the extent and weight of this objection, we thus proceed to a response. All right, so just to say that again.

It's not enough to say that Christianity is not necessarily false, but that's what a lot of people are doing when they are conceding that it can't be proven, you know, or that maybe there's another worldview out there, I don't know, that could be true, right?

They're not saying that Christianity is true, they're just saying it's not necessarily false. You know, even if they wouldn't say it that way, that's what they're conceding. All right, so there are several.

Okay, so there are two parts of this, right? And we're going to spend the most time on the first one, but honestly, it's the second one that's more important, and we'll probably won't get into that until next time.

But the first part is, okay, what really makes Christianity unique beyond all the other religions so that you could say, this is what Christianity has, and this is what no other religion has? And there's at least one thing, which is the Trinity.

And so this is one way that you can think about the fact that, well, Christianity really is distinct. It's not just, okay, we're trying to defend monotheism, and then that rules out any non-monotheistic religion, but then we have to find something more specific.

No, only Christianity has the Trinity. So this is one aspect of it, that Christianity really is unique. There is uniqueness to it. Part of the reason why the hypothesis of consistent non-Christian worldview is so prima facie unsettling, that means on the face of it unsettling, because it preys on a misunderstanding regarding Christian theisms claimed to provide the preconditions of intelligibility.

Preconditions of intelligibility being, you know, how is it possible for there to be knowledge? You know, would that really be possible without the Christian God in particular? It is not merely as though the existence of a God magically solves all problems, and that any religion with a God is automatically a candidate to provide those preconditions.

So that's what a lot of people think when they are arguing with a Christian. They think that, okay, well, here's a hard problem, and the Christian just says, well, God exists, and that magically solves all the issues.

But if that's all that we're saying, then any religion that has a God, why isn't their God powerful enough, you know, in theory, to have the preconditions for intelligibility? The Christian God is unique, not just because he's real, but because of what he has declared about himself that the other gods have not declared about themselves.

It is not merely as though the existence of a God magically solves all problems, and that any religion with a God is automatically a candidate to provide those preconditions. Instead, the claim of Tagg, at least as articulated by Van Til and his successors, is that the Christian God is so unique and unlike the gods of the world that he cannot be mimicked.

So it's impossible for another religion to come up that would be like this God. It's not just that we haven't found one that has the same qualities as our God that provides preconditions for intelligibility.

It would be impossible for there to be one. Furthermore, it is on the basis of his unique character that he provides the preconditions for intelligibility. Let us return to part one of the response given by B .A. Bosterman.

So this is just repeating the quote we read earlier, the first half of it. First, Van Til locates the destructive feature of unbelieving thought and its reliance on abstractions and not on any particular abstraction, idol, that one advocates.

In this case, until and unless one is able to demonstrate how fallen man could reason without abstract principles or solve the one in many problem with them, the Christian apologist has every reason to believe that his critique is conclusive.

So we may rephrase Bosterman's comment in three points. First, he reasserts that when Van Til or any apologist following in his footsteps demonstrates the impossibility of the contrary, he is indeed showing the problem with all non-Christian worldviews as opposed to showing the problem with a single non-Christian worldview.

Second, so he's dealing with all non-Christian theism, not just one. Second, it is most clear to believer and non-believer alike that reasoning is not possible without abstract principles such as the concepts of being, logic, language, etc.

Third, abstract principles are of themselves incapable of solving a most basic philosophical issue and are thus incapable of providing the preconditions for intelligibility. So in other words, a common response of atheists, if you say, well, you know, how is knowledge possible?

And they'd say, well, it just exists. You know, what's wrong with it just existing? There is a problem with that. This issue, which we will examine shortly, is the problem of the one and the many. Given that a worldview based on abstract principles could not possibly be sufficient to provide those preconditions, they necessarily must be supported by an even more fundamental basis that can, the triune God being the only such foundation.

So yeah, there must be a foundation greater than the principles themselves, right? Love can't just exist. Knowledge can't just exist. Logic, truth, beauty, they can't just exist. There has to be some foundation for them.

All non-Christian worldviews, while each possessing differences from each other, are united under one banner of autonomy from the triune God of Scripture. So what unites all the non-Christian worldviews, right?