The following was adapted from Greg Bahnsen's Lecture titled, Van Tillian Apologetics, Part 2.

Bahnsen on circular reasoning

We aim to acknowledge, not emulate the approach of some adherents to Van Til's philosophy, who may convey that circular reasoning is acceptable. It is crucial to specify the nature of the circular argument we endorse.

If an individual asserts:

Your argument comes down to this: The Bible is true because the Bible is true!

This is not the argument we put forward. It would be beneficial to refer to Bahnsen's debate with Gordon Stein. In that discussion, Stein accuses Bahnsen of employing the very reasoning we're critiqued for. However, Bahnsen never argued circularly by claiming the Bible is true merely because it asserts its truth. This type of objection has also been raised by figures such as R.C. Sproul, among others.

Nonetheless, our reasoning does involve a form of circularity, as it is predicated on the authority of God as revealed in Scripture.

This means the authority of God as communicated through Scripture shapes our methodology. We utilize this method to ultimately affirm the authority of God as it is revealed in Scripture. Hence, there is a form of circular reasoning involved. However, a more accurate description might be that our system of thought maintains internal consistency. Any system of thought must be internally coherent.

Our approach presupposes the authority of Scripture to substantiate that very authority. While this is not a simplistic logical fallacy of asserting the Bible's truth solely because the Bible claims it, the overarching circular nature of our argumentation might still be problematic for some.

So, what alternative do we suggest? Should we adopt an autonomous stance? When claiming autonomy, what reasoning method do we then apply? Is human reason deemed the ultimate authority? Claiming reliance on reason alone is insufficient, as "reason" can be interpreted in numerous ways, at least 35 by some counts. Thus, the question arises: what kind of reasoning? In the manner of Descartes? Kant?

What does the sceptic aim to demonstrate through reason? That God does not exist and that humans are autonomous. We must then question how he intends to validate reason as the supreme standard. What will be his reference point? The sceptic faces a dilemma: he must appeal either to reason or to something other than reason. If he chooses the latter, reason cannot be his ultimate authority.

This places the sceptic in a paradoxical position, relying on reason as the ultimate standard while attempting to validate this choice through the same means of autonomous reasoning.

Faced with this dilemma, the sceptic might assert that his system of thought is internally consistent. Yet, our system, grounded in the authority of God's Word, also claims internal consistency. We use Scripture as the foundational standard to argue that it should indeed be our ultimate guide.

This results in two seemingly circular arguments.

However, this does not preclude meaningful dialogue. We certainly can engage in conversation despite these foundational differences. Let's posit that reason is the ultimate authority for one worldview, while God's Word holds that position in another. Under the authority of God's Word, several foundational truths are resolved:

• The existence of moral absolutes is affirmed.

• The basis for logical reasoning is established.

• The foundation for scientific induction is secured.
  

Conversely, if human reason is deemed the ultimate authority, it leads to problematic conclusions:

• Logical reasoning becomes untenable.

• The scientific method lacks a foundational basis.

• Ethical standards become indefinable.
  

While both perspectives involve circular reasoning, the circle formed by the sceptic's worldview undermines the very possibility of acquiring knowledge. Claiming ignorance on all fronts is itself a paradoxical stance since asserting 'we know nothing' is, paradoxically, a claim of knowing something. Thus, the sceptic's position becomes untenable.

The question then arises: How do we ascertain the truth of the Christian worldview? Van Til offers a compelling argument for God's existence as the linchpin of our ability to know anything at all. Without God, he argues, the foundation for proving anything disintegrates.

The Circle of the Globe :)

Jason Lisle on Circular Reasoning

The following was adapted from Jason Lisle's article titled, The Ultimate Standard

Jason Lisle writes the following:

Revelation is the giving of some of God’s thoughts to man.  The question is how do you know that these thoughts are from God?  How do you justify them? So the question I am going to ask you is, “How do you know that the Bible is revelation from God?”  Can you answer this without any degree of circularity?  Bahnsen says you can’t.  For any answer you give will implicitly assume the truth of the Bible.

Presuppositional apologetics posits that reasoning must occur within the confines of the Christian worldview to truly attain knowledge. Outside this framework, all beliefs remain fundamentally unjustified, as knowledge originates from God, as stated in Proverbs 1:7.

The concept of begging the question, or the petitio principii fallacy, describes an argument that assumes its conclusion as a premise, and as such becomes circular in nature. However, circular reasoning isn't inherently fallacious; it can manifest in either a vicious or virtuous manner. A vicious circle is one where the circularity is arbitrary, aligning with the petitio principii fallacy.

Conversely, a virtuous circle involves rationally necessary premises, hence not arbitrary and not a case of petitio principii. For instance, the argument that the existence of logical laws is necessary because arguing against them requires their use is circular but virtuously so, as it logically presupposes the very logic it seeks to validate.

Similarly, the argument for the Bible as divine revelation incorporates an element of circular reasoning. To establish the preconditions of intelligibility—necessary for proving anything, including the divine nature of the Bible—we must presuppose the Bible's revelation. This circularity is not only inevitable but also virtuous, as rejecting this presupposition would lead to a state where knowledge is unattainable.

Some further thoughts

Let's consider sense perception as an example. How do we establish the general reliability of our senses? Some might elevate sense perception to the status of their ultimate standard. Bahnsen points out that to justify the general reliability of sense perception, one must either:

1. Use their senses.

2. Appeal to something other than their senses.
   

Choosing the second option undermines the authority of sense perception. However, justifying senses with senses entraps the individual in circular reasoning. It's not inherently rational to assume our senses always operate correctly; indeed, we know instances where they do not. Thus, the circular reasoning employed by those who rely solely on sense perception for justification is arbitrary and fallacious.

Moreover, deriving concepts like ethics, laws of logic, and scientific induction solely from our senses is untenable. Our senses, devoid of reasoning, convey limited understanding, a point Bahnsen emphasizes.

Why, then, is the Christian circle not deemed arbitrary?

Jason Lisle argues for its rational necessity. Just as disputing the laws of logic necessitates their use, challenging the Christian worldview invariably involves presuppositions that originate within it. Similarly, proving the Bible's authority without presupposing its divine inspiration renders the concept of proof nonsensical.

This line of reasoning forms the basis of a transcendental argument, highlighting that certain presuppositions are indispensable for making sense of our experience and knowledge.

Closing Thoughts

The proof of the Bible isn’t a vicious circle such as “The Bible is God’s Word because it says it is.” Rather, the proof is that the Bible says it is God’s Word and makes knowledge possible.  This is something the Bible itself indicates (Proverbs 1:7, Colossians 2:3). The Bible proves itself and is the only basis for proving anything else. It’s not a simple (vicious) circle, but a spiral that goes beyond itself and justifies our other beliefs. The proof of the Bible is the impossibility of the contrary. If the Bible were not true, we couldn’t prove that anything is true.

Jason Lisle, The Ultimate Standard