Many presuppositionalists would agree that the theistic proofs as historically articulated by the classical Christian theists are just fine so long as they are used “within the context of the entire system of doctrine revealed by God in the Scriptures.”[1] But what does this mean? How does, for example my presentation of the cosmological argument differ from that of a presuppositionalist’s?

Greg Bahnsen’s Explanation

Dr. Greg Bahnsen, who was a dear brother in the faith, a towering figure who ardently defended the Gospel and remained committed to the Gospel until the very end, explains this in further detail. He writes:

It is this entire underlying worldview that is being defended, even when we answer a more narrow, particular attack. We cannot talk about everything at once, of course, but the specific matters about which we argue with the unbeliever are always understood and defined within the broader framework of God’s full revelation. Thus, we do not attempt to defend the resuscitation of a particular human corpse, and then attempt to add an argument that this revived individual is also a divine person (etc.); rather, we set forth and defend the resurrection of the incarnate Son of God. Likewise, the Christian apologist does not argue for just any kind of abstract, general theism (‘a god of some sort or other”), but rather for the specific conception of God revealed within the Christian Scriptures.[2]

I agree with Bahnsen here that our aim, ultimately, is to defend the Christian faith. And even Bahnsen recognizes that this happens in a more isolated fashion as we argue about one facet of the faith or another. And this way of thinking is absolutely consistent with the classical way of reasoning with unbelievers. To do what Bahnsen suggests above is not incompatible with our view. We want to argue for the Christian God. However, the same God who has revealed Himself in Scripture has also revealed Himself in nature and so all logically sound deductions from nature do end up at the Christian God. This is why all men are left without excuse, because of what can be known through nature (Rom. 1:18-20).

So, when the classicalist argues, they argue via modus ponens to a necessary conclusion, God. And this God cannot just be any god because, again, only one God has objectively revealed Himself through nature and that’s precisely the God we argue for. There is no warrant in Scripture to include every doctrinal detail in our argumentation, as Bahnsen has already admitted. Nor is there any Biblical warrant to suggest our conclusion must conclude at God inasmuch detail Scripture reveals about Him. Paul, in Acts 17, does not include every biblical doctrine in his argumentation, nor does he conclude at the fullest expression of the Christian God. Thus, we are to be held to no such standard.

“Within the Context of the Christian System”

When Bahnsen says our claims must be understood in light of the Christian system, the classical Christian agrees. The classicalist admits that he’s defending the Christian God in his argumentation, or at least should admit to such. What the classicalist will not do is defend the conclusion with the conclusion in his argumentation. At this point, we should make a distinction between practical argumentation, that is, what the atheist hears coming out of our mouths, on the one hand; and the Christian apologist’s assumptions which may or may not be brought to bear in an argumentative situation.

When the presuppositionalist claims that classical arguments are fine so long as they are used within the context of the Christian system, it is rather unclear what they mean. To clear things up, we will once more turn to Bahnsen, who writes:

The apologetical program can be pursued with the aid of theistic proofs (8.3) or empirical evidences (8.4), provided such arguments are not offered in such a way as to encourage the unbeliever’s autonomous reasoning (8.1). The arguments of the Christian apologist should attack the unbeliever’s assumed intellectual independence, presenting a “transcendental” challenge to his would-be autonomy.[3]

Classical or theistic proofs may be utilized so long as they do not “encourage the unbeliever’s autonomous reasoning.” In addition to the theistic proofs, a transcendental “challenge” or argument (I take it) must be presented. If this is what presuppositionalists mean when they insist classical arguments be used in the context of the Christian system we must ask, Why?

The theistic proofs do not lend anything to the unbeliever except the mutual assumption that they accept the laws of logic and basic reliability of sense perception. Rather, the classical arguments shut the mouths of the unbeliever by demonstrated their inability to use those laws consistently. If the laws of logic are consistently applied to the world around us (and not suppressed in unrighteousness), the necessary conclusion is “God exists.” The problem is that the unbeliever will not follow any argument of the Christian consistently, whether that be the transcendental argument or any other proof. They will suppress, suppress, suppress. At this juncture, it must be noted that the Gospel must be given since it is the power of God revealed for salvation.

In light of what has just been shown above, there is no necessary requirement to use the transcendental argument. And the theistic proofs are not given, by the Reformed Thomist, with the assumption that the unbeliever will accept their conclusions apart from the regenerating work of the Holy Spirit.

Therefore, there is no reason to make necessary the transcendental argument in our approach. A number of arguments may be used. This does not encourage “autonomy,” but merely makes use of the commonalities both believer and unbeliever have––the laws of logic and reason. Our argument demonstrates that the unbeliever is actually reasoning in God’s world so that, no matter how much they want to disagree, they cannot do so without becoming irrational or inconsistent.

The Nature of the Transcendental Argument for God (TAG)

The transcendental proof takes one to the same exact God the theistic proofs do.

It does not include all the doctrinal details of this God, but the details that can be known by men who do not have faith in God’s Word, the Scriptures. The presuppositionalist will, more often than not, frame the transcendental argument as such: The Triune God of Scripture exists by virtue of the impossibility of the contrary. It contains a statement followed by an explanation, outlined like so:

  1. The Triune God exists
  2. Because the contrary is impossible

Now, presuppositionalists are stuck showing how this is the case since unbelievers often begin scratching their heads before the argument even leaves the lips of the apologist. This is one tricky aspect of TAG. It involves the process of elimination by way of internal critique rather than a “one shot, one kill,” type of effect. Transcendental argumentation is messy business. But that doesn’t mean it’s not a good argument. To be sure, it is a good argument and effective in many scenarios. It becomes even more complicated, however, when the apologist slips the word “Triune” into their presentation, as seen above.

Immediately the skeptic will begin asking, “Why should I believe it’s the Triune God which accounts for all reality?” Of course, the presuppositionalist will state that all other worldviews, upon final analysis, will fail to remain internally consistent and, on that basis, ought to be rejected for the sake of logical coherency. But at this point, the atheist ought to be pushed to realize he’s just conceded the existence of God by virtue of asking the question about the Christian God. It’s no longer God the atheist has an apparent problem with, it’s the Christian God. He has basically admitted atheism is false. Nevertheless, they will go on to ask, “In what way do you suppose this is the case, that it is the Christian God and not another god?”

The presuppositionalist is then left doing internal critiques of, not only atheism, but Islam, Hinduism, Buddhism, and the list goes on. The assertion that the Triune God exists by virtue of the impossibility of the contrary will never be argumentatively justified until every worldview is shown to be inconsistent with itself. Otherwise, the opponent of Christianity will just move from one to the next in their challenge of our system.

Moreover, there is nothing in TAG by itself that prima facie necessitates the doctrine of the Trinity. That would involve additional argumentation. TAG “ends,” ends, so to speak, at the exact place the theistic proofs do––with the existence of a God who is a se, intelligent, relational, omnipotent, etc., etc., etc. The take-away from the argument, if the atheist were consistent, would be, “Okay, God exists, Why should I believe it’s the Christian God?” and then further demonstration would have to take place. So, not even TAG can begin with the Christian God and end with the Christian God. “God exists by virtue of the impossibility of the contrary,” is a claim that must be supported with various facts in order to demonstrate its truth. And further argumentation is needed when wanting to move from the obscure expression “God” to the more specific doctrine of the Triune God.

Consider an example. A Muslim may take the same course of reasoning, “Allah exists by virtue of the impossibility of the contrary.” The presuppositionalist is saying the same thing about the Christian God. Both men, Christian and Muslim, have locked horns. They can’t move, until the presuppositionalist begins the internal critique of Islam. But at best, this internal critique may falsify one aspect or another of Islam, and would it be Sunni or Shia Islam? See the complication? Down the rabbit hole the presuppositionalist will go with the Muslim.

Instead, we could falsify their entire system at once, from a classical standpoint. Allah is a monad, he’s not the divine essence subsisting in multiple persons, or relations. But this creates fundamental problems for Islam because the classical proofs lead to a God who is not only a se, necessary Being, divinely simple, omnipotent, etc., but also necessarily relational. We know this is the case because God relates to His creature, His creation itself is relational (think teleology, friendships, etc). If God were not essentially relational, He would be reliant on His creation to be relational, but as it is, God relies on nothing––He’s necessary, as the theistic proofs demonstrate. Therefore, since God created and since creation is fundamentally relational, we know He is relational by nature. If God is relational by nature, He must have actual relations in Himself since relationality is not merely an object of the imagination but consists of actual relations.

Therefore, Allah, who is not One in many, cannot be God since the classical proofs lead to a very different God than the one conceived of by Islam. I think the transcendental argument can be used in this way as well but, then again, if it is stated like Bahnsen states it, it will be necessary to engage in a very long process of elimination. To be fair, Van Til does attempt at least an angle of this kind of argumentation with his discussion of the philosophical problem of the one and the many.[4] Yet, that leads the apologist into more complicated waters than is necessary. Rather than look at the one and many in this world and reason back to God (e.g. the lower universes of discourse imply the upper universes of discourse), we can simply come to a necessary conclusion of a God who is essentially relational in Himself, and this rules out any known conceptions of deity in the history of world religions.


“Van Til’s system of thought is not a simple one,” according to Bahnsen himself.[5] Upon final analysis, the classical way of argumentation is much less cumbersome, and by classical, I do not mean classical apologetics as it is construed by the analytical philosophers such as William Lane Craig. Rather, I mean the concise, yet airtight, argumentation used by Christians for hundreds of years. If the classical method seems difficult, it’s probably because we’ve largely lost the categories with the advent of post-Kantian thought. But, there is no reason why we should settle for Kant’s categories and not try and retrieve what was being used by the Reformers and the Puritans.

Classical Christians do not argue with fanciful hopes their opponents will, on their own, do what they’re supposed to do with the arguments, that is, accept them. Rather, classical Christians argue in hopes, much like the presuppositionalist, that God will use arguments as a means to make impressions upon the unbeliever or at least prepare their heart for the hearing of the Gospel, which alone delivers sufficient knowledge unto salvation.

[1] Greg Bahnsen, Van Til’s Apologetic, 30.
[2] Ibid., 30, 31.
[3] Ibid., 701.
[4] Cf. Cornelius Van Til, An Introduction to Systematic Theology.
[5] Van Til’s Apologetic, 698.

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