A Considered Response to Mitchell Leblanc on The Transcendental Argument for the Existence of God

Below you will find a reprint of an article from philosophy student Mitchell Leblanc (of urbanphilosophy.net) making an effort at refuting the classical Van Tillian use of TAG (the Transcendental Argument for the existence of God), with my responses interspersed throughout in italics.

Introduction

Cornelius Van Til set the foundation of an argument for the existence of God that focuses on certain tenets. Van Til believed that (i) everyone has knowledge of God, some just suppress it (ii) Natural theological arguments are ineffective because they do not prove the Christian God uniquely over any other, (iii) we all have presuppositions which either assist or defeat our truth-seeking intentions (all non-Christian presuppositions defeat such intention), (iv) it can be shown that without Christian theism as an adopted worldview, the intelligibility of the world is lost, that one cannot make sense of logic, morality, or science. Van Til’s system became known as presuppositionalism and the modern scholars which have taken up a defence of his position include Greg Bahnsen and John M. Frame.

The most intriguing part of presuppositionalism is the assertion that there is, and only can be, one argument for the existence of the Christian God. With the exception of Frame, presuppositionalists largely reject traditional arguments for the existence of God claiming, as Van Til, that they offer only the mere probability of God’s existence and not the certainty that a Christian requires[2].

As such, Van Til proposed a transcendental argument. Transcendental arguments have origins which trace back to Immanuel Kant and generally take the form of modus tollens:

P

If not-Q then not-P

Therefore, Q

We can find an example of such an argument in Descartes’ Cogito:

I am thinking

If I do not exist, then I am not thinking

Therefore, I exist

The unique purpose of transcendental arguments is in many ways geared towards addressing the skeptic[3]. The arguments begin with a premise with which even the most hardened skeptic will agree and move to show that there is a precondition of that premise which cannot, thereby, be denied. In the above example of Descartes’ Cogito, existing is found to be the necessary precondition of thinking.

In the case of Christian theism, the transcendental argument employed is one which asserts that God is a precondition for the existence, and intelligibility of logic, morality, and science (amongst other things). For the purpose of this paper, I will focus on the claim that the existence of the Christian God[4] is a necessary precondition of the existence of logical principles[5]. I will present a formulation of such an argument, but first I would like to clarify what the TAG is asserting.

Throughout presuppositionalist literature is this notion of needing to “account” for logical principles. To be sure to understand what is meant by this, it would be prudent to present an excerpt from presuppositionalist Greg Bahnsen in his debate with atheist Gordon Stein[6]:

What are the laws of logic, Dr. Stein, and how are they justified? We’ll still have to answer that question from a materialist standpoint[7]. From a Christian standpoint, we have an answer – obviously they reflect the thinking of God. They are, if you will, a reflection of the way God thinks and expects us to think.

With the argument presented informally, I now introduce a formal version.

The Transcendental Argument Stated:

Sean Choi, in his criticism, offers us the following formulation of the TAG[8]:

(1) There is a rational justification for the laws of logic

(2) It is necessary that: if Christian theism is false, then there is no rational justification for the laws of logic

(3) Christian theism is true

In support of (2), Choi observes the justification as being:

(2a) It is necessary that: if there is a non-Christian theistic way to justify the laws of logic, then it will be either the a priori way or the a posteriori way or the conventionalist way

(2b) It is necessary that: neither the a priori way nor the a posteriori way nor the conventionalist way will justify the laws of logic

(2c) Therefore, it is necessary that: there is no non-Christian theistic way to justify the laws of logic

Initial Objections

There are a number of criticisms which Choi makes in his paper. He chooses to grant premises (1) and (2a) though with regard to (2a) while he does grant the premise for the sake of argument, he notes that it may be a false trillema. I am inclined to agree with Choi’s analysis. It seems to me that some hybridization of any of the mentioned means of justification may bring about a new means of justification. For example, a hybridization of an a priori and conventionalist system may succeed in providing the justification of logic sought by Bahnsen, but in a manner wherein the new system may be thought of as unique to both previous a priori systems, and forms of conventionalism.

Mitch starts off on the wrong foot immediately by proposing a hypothetical "hybridization" of two positions which is also "unique" to those other positions. So, is it a "hybrid" or is it "unique"?

If there is a non-contradictory way of producing such a system which is not ultimately reducible to one of the non-hybridized positions and provides the justification of logic then Mitch ought to present it, rather than giving some imaginary, contentless alternative as though it were an actual objection. Some arguments need only be repeated in order to be refuted.

Also, Mitch borrows from Sean Choi's understanding of TAG as reducible to modus tollens. However, advances have been made in presuppositionalism which have shown Choi's position to be mistaken. Don Collett has argued effectively (in Revelation and Reason edited by K. Scott Oliphint) that Van Til's conception of presuppositional semantics is identical to the Strawson/Van Fraasen semantics, which makes a clear distinction between "presupposition" and "implication." (Even John Frame has accepted Collett's argumentation in this respect.) If Mitch is unaware of these advances in presuppositional apologetics and its implications regarding TAG, he need only have asked Chris Bolt about them. I happen to know that he's a pleasant fellow, apt to teach, and would have gladly shared this information, helping prevent Mitch from misunderstanding TAG and criticizing his own misunderstandings.

Elsewhere in his presentation[9] Choi presents a criticism of (2b) by outlining the sheer impossibility of a TAG defender showing that every possible a priori, a posteriori or conventionalist way of justifying the laws of logic fail. Of course, the TAG defender may succeed if they show that all defences of either an a priori, a posteriori or conventionalist justification depend upon a particular claim that can be shown to be false.

Bahnsen seems to think that any a priori, a posteriori or conventionalist justification of the laws of logic is incompatible with Christianity. That is to say, if one is justifying the principles of logic in any of these manners, they are employing tenets rejected by Christianity. In other words, Bahnsen believes that it follows from ‘Christianity is true’ that ‘the a priori way, a posteriori way and the conventionalist way fail to justify the laws of logic’ for if Christianity is true, the laws of logic can only be justified in the manner he presents[10]. By doing so, Bahnsen asserts that non-Christian justifications operate on the presupposition that Christianity is false. As such, in an attempt to avoid the arduous task of showing that all flavours of the aforementioned possible justifications are false (and thereby that any worldviews that employ them are false), he seeks only to show that they all depend upon a particular claim, that ‘Christianity is false’, and that this claim renders everything unintelligible. Clearly, Bahnsen has drawn a dichotomy wherein one either accepts Christianity, or wholly rejects it; no middle ground is possible. As Bahnsen states[11]:

It is absolutely crucial that transcendental argumentation begin by positing that Christian theism is either true or false…. Van Til’s defense of the faith does not require the apologist to be aware of and refute every single variation of unbelieving philosophy, but only the presupposition common to them all (namely, the rejection of Christian theism). Many apologists mistakenly imagine that there are really three options available: one may accept Christianity, reject it, or be “undecided.” But, as Van Til recognized, to be undecided about the claim that Christian theism is the presupposition necessary to make sense out of any reasoning whatsoever is to begin one’s reasoning on the operational assumption that this claim is false (and can be laid aside as one proceeds to research and develop one’s views). Since there are only two options at the most fundamental level – the truth or falsity of Christian theism as a presupposition – the refutation of the unbelieving one (in whatever illustrative variation it appears) is an indirect proof of the other.

But what might this mean for our discussion? If Bahnsen is permitted to carry on with his criteria, then if any a priori, a posteriori or conventionalist justifications of logic are shown to be false (and subsequently, the worldviews that house and depend on them) all other formulations which properly fall under those headings will also be false (worldviews included) since they employ the same proposition, namely, ‘Christianity is false’. Of course, this is not sound reasoning unless the shared proposition is what is causing the justification to be false. Bahnsen needs to show that ‘Christianity is false’ is the ‘false-making’ proposition of all non-Christian worldviews, and it doesn’t seem that this is possible by any means other than (i) showing that all possible non-Christian justifications will have ‘Christianity is false’ as the only proposition in common (for if there is even one other proposition shared by these worldviews, how might one disqualify that proposition as possibly being the ‘false-maker’?), and (ii) showing that Christianity is not false. The obvious problem is that if (ii) is shown, the TAG becomes superfluous as it is no longer needed; one has already arrived at the truth of Christian theism, and for (i) to be shown, one still has to have an awareness of “every single variation of unbelieving philosophy.”

This was a rather surprising error to me. I would have thought, given that Mitch cites Bahnsen's Van Til's Apologetic (which implies he has read it; see "Note" in paragraph below), that he would see that this objection is far wide of the mark. It is the axiomatic nature of the presupposition "Christianity is false" which puts it in the role of "false-maker" (as Mitch puts it) and this is clear from the quote which Mitch himself uses above. Mitch not-so-carefully diverts from Bahnsen's language of presupposition to that of mere proposition regarding the role of "Christianity is false" in a given worldview. One is left to wonder if this is the result of a superficial familiarity with the material being criticized, incompetence or dishonesty. (I have no good reason to doubt Mitch's competence or honesty.)

If the most basic presupposition of a non-Christian worldview is "not Christianity" (which appears to be definitional, given the above framework), then it is the basic nature of the presupposition which exerts a rational controlling influence on all other worldview content. It is not merely one proposition among many, floating loose and free in a certain worldview, but is rather foundational. To miss this is to miss the entire point of presuppositional semantics in Van Tillian apologetics, which is a rather large point to miss if one desires to criticize presuppositionalism as such.

Mitch rightly recognizes that rebutting one form of non-Christianity does not disprove all other forms of non-Christianity. However, he appears to severely overestimate the number of categories of non-Christian positions. It is finite, which means establishing the transcendental premise via Van Til's project of reductio ad absurdum is empirically possible. (In fact, this is a place where the classical apologetic work of someone like Norman Geisler may be of adaptable worth to the presuppositionalist.)

(Note: Mitch quoted above from Van Til's Apologetic p. 277 (Mitch's note #11). Interestingly, the quotation he cites is taken verbatim from footnote 28 of Sean Choi's chapter on the Transcendental Argument in Reasons for Faith edited by Norman Geisler and Chad V. Meister. In the following sections of his paper Mitch borrows exclusively from Sean's formulation of the "Fristianity" objection to TAG, as found in Reasons for Faith. I would posit that Mitch has not read VTA. Why? When I say that Mitch quoted verbatim from Sean's footnote, I mean he even includes the ellipsis where Sean does. The quote above is actually just a footnote on pg. 277 of VTA; the elided section states: "(see chap. 7 below)". Now what's the significance of this? Well, in the context of Sean's original footnote, he quotes the footnote because he thinks the statements are the closest thing to a defeater for the Fristianity objection which Bahnsen provided and chapter 7 of VTA has nothing to offer in that respect; so why shouldn't Sean leave it out? However, in the context of Mitch's quotation it is presented as a concise summary of Bahnsen's approach to TAG. But chapter 7 of VTA is all about apologetic arguments, including nearly 30 pages explicitly detailing Bahnsen's understanding of TAG. Why does Mitch quote a footnote from a footnote as representative of Bahnsen's presentation of TAG rather than interacting with the more detailed and extensive argumentation in chapter 7 of the same book? Given Mitch's heavy reliance on Sean's work for both his mistaken formulation of TAG as modus tollens and the Fristianity objection, his verbatim quotation from Sean's footnote, his demonstrated general lack of familiarity with presuppositional semantics and transcendental arguments, and his lack of interaction with Bahnsen's most explicit published work on TAG (ch. 7 of VTA), the simplest conclusion is that he hasn't read Bahnsen, he's only read Choi criticizing Bahnsen. Which doesn't count as scholarship. Anywhere.)

Further, Choi rightly points out that this criterion for distinguishing between the Christian worldview and all others is insufficient. He shows the absurdity of the criteria when applied to another worldview, namely, Fristianity[12]. Fristianity is a worldview adopted by Choi, which is identical to Christianity with the exception of the triune godhead, to make the point that the claim that “non-Christian” worldviews cannot account for X is false, since in whichever way Christianity accounted for X, Fristianity would do so in the same manner. The distinguishing feature of Fristianity is that its godhead is a quadrinity rather than a trinity, it is essentially a “Christianity + 1”. Michael Butler, a defender of TAG, has responded to the Fristianity objection by stating that there is no guarantee that Fristianity will be a coherent worldview after it is laid out and thus cannot be an objection to the TAG[13]. Choi’s reply is that this is simply besides the point as the TAG, if successful, should prove that Fristianity will be incoherent outright and that there is no burden on the Fristian to exemplify coherence. Further, in response to Bahnsen’s statement that there can only two worldviews, “the believing one and the unbelieving one”, Choi notes:

…on the same basis the hypothetical Fristian could argue as follows: ‘There are only two worldviews, Fristian theism and the unbelieving one’—which is to say, any worldview that has as its presupposition the rejection of Fristian theism. All the alleged worldviews (and here we would have to include Christian theism) are really just variations on a common presuppositional theme that Fristian theism is false

In other words, we may not simply claim that all worldviews which share a certain proposition are false because some worldviews which share a certain proposition are such. It needs to be shown that the worldviews are false because of the shared proposition. Under Bahnsen’s proposal, an atheist could show one theistic worldview to be incoherent, and reason from this that all theistic worldviews, including Christianity, are incoherent since they all share the same presuppositional theme, that atheism is false. Clearly, an exhaustive examination of possible worldviews is still required if one wants to make the strong claim made in (2b).

Being quite thoroughly familiar with various Fristianity objections, I had to chuckle at this one. I apologize for it, but I did. Let's be perfectly clear here: an atheist can get zero cash value out of the Fristianity objection in debate with a Christian. Are you planning on being baptized in the name of the Father, Son, Holy Spirit and "Fred" anytime soon, Mitch?

Fristianity doesn't refute the Christian TAG, it merely shows how closely a worldview needs to mirror Christianity in order to provide the necessary preconditions for intelligibility. If an atheist's positive epistemic resources are so depleted in responding to a Christian apologist that he must fall back onto the Fristianity objection in order to respond to TAG then the Christian need only ask whether or not the atheist would like to become a Fristian or a Christian. If he wishes to adopt neither (and maintain his status as a rational being) then the whole objection is superfluous to the debate. Let me emphasize this point: Fristianity doesn't overturn the TAG for Christianity, but leaves Christianity and Fristianity as the only epistemically viable worldviews, which would seem to be an undesirable argument for an atheist to present, given the extreme similarity between Fristianity and Christianity. While Fristianity does present some intramural issues for discussion regarding the strong modal TAG amongst presuppositionalists, it is of no value to the atheist interloper.

Let me humbly suggest that Mitch should study presuppositionalism qua presuppositionalism before criticizing, rather than merely assimilating various second-order criticisms of presuppositionalism.

The Transcendental Argument for the Non-Existence of God

I would like to call attention to a statement made by Bahnsen in the excerpt taken from his debate regarding the Christian’s justification for logical principles: “From a Christian standpoint, we have an answer – obviously they reflect the thinking of God. They are, if you will, a reflection of the way God thinks and expects us to think.” [14] This is supposed to be the factor that separates Christian worldviews from non-Christian worldviews, but the claim seems rather vague. What does it mean to say that the justification for logical principles is the fact that they reflect the thinking of God?

Michael Martin asks a similar question and formulates a Transcendental Argument for the Non-Existence of God (TANG) which he defended against criticisms from John Frame.[15]

Martin stated[16]:

How might TANG proceed? Consider logic. Logic presupposes that its principles are necessarily true. However, according to the brand of Christianity assumed by TAG, God created everything, including logic; or at least everything, including logic, is dependent on God. But if something is created by or is dependent on God, it is not necessary–it is contingent on God. And if principles of logic are contingent on God, they are not logically necessary. Moreover, if principles of logic are contingent on God, God could change them. Thus, God could make the law of noncontradiction false; in other words, God could arrange matters so that a proposition and its negation were true at the same time. But this is absurd. How could God arrange matters so that New Zealand is south of China and that New Zealand is not south of it? So, one must conclude that logic is not dependent on God, and, insofar as the Christian world view assumes that logic so dependent, it is false.

Let me just briefly point out that Martin has not presented a "transcendental argument" for anything here. "Logic presupposes that its principles are necessarily true." This is neither transcendental nor an argument. The remaining section is a reductio ad absurdum, not a TA. Martin has simply used the common atheistic tactic of inverting a theistic argument and calling it something akin to that theistic argument, demonstrating the persistent parasitic nature of much atheistic argumentation. And, as Frame points out below, it is a straw man.

Frame’s response[17] stated that:

Logic is neither above God nor arbitrarily decreed by God. Its ultimate basis is in God’s eternal nature. God is a rational God and necessarily so. Therefore logic is necessary. Human logical systems don’t always reflect God’s logic perfectly. But insofar as they do, they are necessarily true.

Bahnsen and Frame’s defence of the TAG depend upon two claims:

(A) Logical principles (such as the Law of Noncontradiction) exist because God exists and the principles are reflections of his thinking[18]

(B) Logical principles cannot be changed by God as their ultimate basis is in God’s nature, and God is necessarily a rational God.

A Logical Euthyphro Application

In analyzing both (A) and (B) it seems that the famous Euthyphro dilemma can be applied to the TAG, substituting notions of ‘goodness’ for ‘logical principles’. The dilemma could perhaps be expressed as the following: does God think in a certain way because it is logical to do so, or is thinking in a certain way logical because God does it? If the first horn of the dilemma holds it seems clear that logical principles exist independently of God. If the second horn of the dilemma holds logical principles seem to be under the whim of God, meaning that God could change them. A TAG defender might respond by saying that this dilemma is a false one, and advocate similar to Frame that logical principles have their basis in God’s nature and are thus neither external, nor arbitrary. Firstly, this seems to add some confusion: are logical principles based on God’s thinking, or on his nature? Frame’s above statement in response to Michael Martin seems to indicate that both are true: logical principles reflect the thinking of God and the thinking of God has its basis in God’s nature.[19]

Frame essentially makes the claim that it is logically impossible for the nature of God to change. But the standard Frame is using to identify logical possibility is allegedly the nature of God. As such, his claim appears to be represented more accurately as:

(C) Based on God’s nature it is logically impossible for God’s nature to be different because God is necessarily a rational God

This does not seem to assist in any regard as what is rational is allegedly determined by God’s nature. So to argue that God’s nature must be the way it is because God is necessarily rational seems to only appeal to a standard of rationality that is separate from God, otherwise it is clearly circular.

In what manner would it be the case that God’s nature was not rational? It does not seem that a God who forms the basis of logical principles and thereby is the standard of rationality can ever be irrational (though he may certainly appear irrational when judged by a foreign standard). That is to say, if one wants to state that the Christian God forms the basis of rationality and the logical principles thereby in effect cannot be anything other than what they are, they must be appealing to a standard of logic that is separate from God’s nature as to appeal solely to God’s nature does not sufficiently answer the question; it is a non-answer.

The problem with Mitch's Euthyphro dilemma is that it is "clearly circular." The Christian's argument is that logical laws are a reflection of God's thought which is in accordance with God's nature, which are all necessary. The first horn of the Euthyphro Dilemma then begs the question in asserting that there is a meaningful sense in which logic is independent of the thought of God. But no argument is presented for this non-theistic conception of logic; not even a definition is given. If the Christian is correct, then positing logical principles which exist independently of God is the real "non-answer." Mitch says that it is circular for a Christian to state that God's nature is the ultimate basis for rationality, while assuming that logic is independent of God in order to prove that logic is independent of God. I don't think Mitch has quite yet grasped the radical nature of presuppositional antithesis. But I hope he does.

God and the Abstract

In his TANG, Martin stated that if logical principles depend on God in any way, they lose their logical necessity and become contingent. Frame countered by making the claim that though dependent on God, the principles of logic have their basis in the nature of God and because the nature of God is necessary, so too are the logical principles.

An obvious defeater to Frame’s claim, and subsequently the TAG, would be to show that not only are logical principles not dependent on God, but they cannot be so dependent.

The dependence relationship between “God exists” and “logical principles exist” seems problematic. If God is the source of all things other than himself, and he depends on nothing for his existence, surely the relationship must be asymmetrical (with primacy granted to God), but it appears not to be. It can be shown, in fact, that God depends on logical principles for his existence.

Consider:

(4) Necessarily, x depends on y for its existence iff y were not to exist, neither would x[20]

Lewis’ counterfactual semantics tell us that ‘any proposition is counterfactually implied by a necessarily false proposition’. Since “logical principles do not exist” is a necessarily false proposition, it counterfactually implies any proposition whatsoever.[21] So it is also true that if logical principles did not exist, neither would God. Thus, God depends on logical principles for his existence.

The relationship between the existence of logical principles and the existence of God would be asymmetrical iff God depended on nothing for his being and logical principles depended wholly on him. In this regard, the relationship of dependence is one-way; logical principles depend on God but not vice versa. If dependence is asymmetrical, then logic cannot depend on God as it has been shown that God depends on logic.

The asymmetrical relationship can be depicted further: where P refers to logical principles and Q refers to God. If P depends on Q asymmetrically, then the worlds in which P is true must be a proper subset of the worlds in which Q is true. Since it is the case that the principles of logic hold in every world, and the set of all worlds is not a proper subset of any other set of worlds, the laws of logic cannot depend on anything, including God.

In order to overcome this problem, one could deny the necessary existence of logical principles. This seems antithetical to the presuppositionalist position which seeks to show that the only way to make sense out of logical necessity is through the existence of the Christian God. Indeed, the opposite becomes true; the only way that logical principles can be necessary is if “logical principles depend on God” is false. One could further deny the claim that “God depends on nothing else for his existence”, but this seems incompatible with Christian theism and perhaps even with a more general notion of God.

In this section the argumentation becomes rather muddled. Given the nature of the points under contention (the existence of God and the relationship between God and logic), to argue that "logical principles do not exist" counterfactually implies that God depends on logical principles for his existence is to beg the question in a rather bald and obvious sort of way. How about, "God does not exist" is a necessarily false statement? Given that TAG is intended to argue for the necessary existence of God, to assume the contingency of God's existence upon logic in order to prove God is contingent upon logic is, well, unpersuasive (to put it mildly). Any use of subjunctive conditionals in arguing about the necessity of God's existence will necessarily beg the question, given the nature of necessity. Necessarily. :)

Again, Mitch has simply assumed that logic is independent of God in order to prove the same.

Another possible solution is twofold. One must first accept that abstract objects are the thoughts of God. This is not problematic for the TAG proponent as they have already explicitly stated that this is the case. One must then further embrace the Doctrine of Divine Simplicity (DDS) and accept that God is identical with each of his attributes and thoughts. Under this view, the statements “God exists” and “Logical principles exist” express the same proposition. This eliminates the problem because any proposition is counterfactually dependent on itself. But it is not clear that DDS is a coherent option[22]. Indeed it is not clear that the principles of logic can be thought to be attributes of God, in any capacity. This problem seems even more severe for the Christian. If the proponent of the TAG attempts to establish the conclusion that the Christian God exists, but has to accept the DDS to do so (as per the above objection) it is unclear as to how they would reconcile the fact that God is identical with his attributes and the belief that he is internally distinct as a Trinity. Indeed, if DDS is coherent, how can there be any distinction whatsoever between God the Father, God the Son and the Holy Spirit? The DDS seems wholly incoherent with Christian theism.

As such, in order to avoid the consequence of conceding that God is not entirely sovereign, one must either (i) deny that logical principles are necessary (ii) deny Christian theism. Both are unacceptable consequences for the proponent of the TAG.

We're then treated to a rather brief, cursory series of assertions regarding the incompatibility of divine simplicity with Trinitarianism and the existence of logic. Frankly, since no argument is presented, no refutation is necessary. All that is demonstrated here is a thorough-going unfamiliarity with the standard works on Trinitarianism and divine simplicity.

The Mind of God

There is yet another respect in which the TAG is vague. It states that the Christian worldview can account for the laws of logic because they have their basis as reflections of God’s thought. Presumably, this means that the reason why the Law of Non-Contradiction (LNC) is the way it is depends on the fact that God cannot avoid thinking in accordance with it due to his nature as logical. Even temporarily disregarding the previous objections, this claim seems dubious. This justification or grounding of the principles of logic does not seem to necessitate any transcendental reference. Consider Bob the Conventionalist[23]; he is a normal human being. Even as a conventionalist, Bob cannot help but think in accordance with the LNC, for how could Bob visualize the effects of a proposition that is both true and false simultaneously? If, as per Bahnsen’s statement, logical principles are reflections of the way God thinks and further if it is true that the LNC exists and holds because God cannot think that p and not-p, surely Bob’s own inability to think that P and not-P fulfills the same justification requirement.

One foreseeable objection is that Bob’s self-grounding does not explain the seeming universality of the LNC. However, it is impossible to think of anyone in existence who could visualize the effects of a proposition which violated the LNC[24] and in this regard the LNC is universally self-grounded.

In the aforementioned debate, Bahnsen criticized conventionalism for being arbitrary and potentially giving way to people with contradictory logical systems. Though it is hard to imagine someone who has adopted a logical system in which there is no LNC or equivalent mechanism. Such a system would be as trivial as a magic eight-ball that answers “yes” to every question[25]. It is difficult to see why Bob or any of his friends would adopt a system with no mechanism to differentiate between any propositions. On pragmatic grounds, it is entirely useless.

One may make the case that Bahnsen has misunderstood conventionalism[26], and one might further make the more interesting point of asking how God accounts for the laws of logic. If it is even possible that God justifies his use of logic in either an a priori, or conventionalist manner[27] premise (2b) of the TAG can be further rejected.

What might it mean to say that God justifies logic in an a priori manner? Bahnsen’s criticisms of an a priori justification can be found in his debate with Stein:

But if you don’t take that approach and want to justify the laws of logic in some a priori fashion, that is apart from experience, something that [Stein] suggests when he says these things are self-verified. Then we can ask why the laws of logic are universal, unchanging, and invariant truths – why they, in fact, apply repeatedly in the realm of contingent experience.

He argues that an a priori justification of the laws of logic does nothing to explain their universality. But, the fact that the laws of logic would be known a priori to be logically necessary does seem to explain the universality in a ‘self-verifying’ manner; they are necessarily true. One might further press to ask why it is the case that they are necessarily true rather than not and one possibility is that they are justifiable in some Platonic manner, existing as brute, primitive facts. In essence, this is presumably how God would view his a priori justification. For God, these logical principles are “just there” even if necessarily “just there”.

It may also be possible that God justifies logical principles conventionally, assuming them for a purpose. One possible objection is that if this is the case, God could have done otherwise (chosen a different convention). It seems that if there are multiple sufficient conventionalist justifications of logical principles, God certainly would possess the capability to select the best possible and employ it on pragmatic grounds.

If these justifications are even possible, then (2b) in its current form becomes demonstrably false. Of course, it may be reworded to state:

(2b*) It is necessary that: no human forms of either a priori, a posteriori or conventionalist justification will justify the laws of logic

It would be the duty of the TAG proponent to develop an explanation as to why it is either impossible that God justify logical principles in the aforementioned two manners or why a human version of the same justification must necessarily fail.

One might object to (2b*) stating that a divine form of a priori justification or conventionalism would not differ sufficiently from a human form but space does not permit a treatment of this claim here.

Finally, we have a section where logic is said to be both conventional while necessary and universal. This is rather fun. It's like something from Alice in Wonderland. "Sentence first - verdict afterwards!"

Conclusion

Given (i) the initial objections, (ii) the vague and troubled explanations of what it means for God’s nature to be logical, (iii) the lack of asymmetry in the relationship between logical principles and God’s existence, and (iv) the possibility that God accounts for logic with the same justifications criticized by the TAG, it is my proposal that, pending further defence, the Transcendental Argument for the Existence of God be considered unsound and unsuccessful in its goal of establishing the existence of the Christian God[28].

My conclusion, in brief: the paper appears to be a scatter-gun reiteration of information found via cursory internet research rather than a responsible familiarity with the standard works on the subject under consideration. While I'm happy to see a bright young philosopher taking an interest in Van Tillian apologetics (even if it is a critical interest), I would recommend doing a far more thorough study of the subject. I might start here. And I might read to understand the matter for myself before attempting to criticize, not vice versa.