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TAG Summarized & Explained

Guest Post by: Joshua Pillows

An in-depth historical survey of Christianity would quickly evidence not just the variety of apologetic giants of the faith, but also the plethora of arguments used to defend the veracity of Christian theism. In antiquity Christianity produced apologists who sympathized greatly with Greek philosophy (not surprising given the overlap of Greek philosophy, the Roman Empire, and the genesis of Christian history all coinciding at or around the time of Christ). They embraced what is called a Socratic method, operating under secular presuppositions, borrowing from the Greek mindset to prove very probably that Jesus is God, and that Christianity is true. Aquinas ushered in a new age of apologetics (and apologists) in the 13th century that would dominate the West for nearly a millennium, an influence that reached far enough even to impact the Reformers. It was not until the 20th Century primarily that Western Christianity saw a popular dispersing of differing apologetic methods from prior centuries—evidentialism, design arguments, cumulative case apologetics, the rationalistic proofs of Aquinas, and more. Granted that design arguments and semi-Gnostic arguments from Being existed centuries after Aquinas, we have never seen such an eclectic and diverse climate of apologists as there are today.

Perhaps the most recently-produced apologetic (and thus the youngest in the entirety of Christian history) was formulated by the late Cornelius Van Til. His presuppositional approach, as ahistorical as it is often criticized to be, is based on a consistently Reformed approach to Scripture, finding its justification not merely in the Bible alone, but also evidences itself in the theology of Augustine and Paul. A distinctively Reformed approach, presuppositionalism rests on biblical authority, not succumbing to the pretenses of neutrality and the alleged correctness of autonomous human reason as has been believed and adhered to for the entirety of Church history. Presuppositionalism emphasizes the fundamental antithesis between believers and unbelievers and therefore argues over worldviews. In short, the presuppositionalist asks which worldview can consistently make sense out of the uniformity and intelligibility of human experience. It is through this medium that it seeks to prove the existence of God and all the truths of Christianity therein.

Much of the fundamental misunderstandings (and therefore criticisms) of Van Til’s apologetic stem from the precise nature of this particular proof. Specifically, presuppositionalism embraces what is known as a transcendental proof for the existence of God, arguing over presuppositions of differing opponents’ worldviews and from the impossibility of the contrary—that Christianity alone makes sense out of the intelligibility of human experience and therefore any contrary anti-Christian philosophy of life is impossible. It is quite obvious to many that this particular proof deviates from the “accepted norms” of inference patterns found in every other apologetic methodology and as such warrants this conversation to turn briefly to a survey of different kinds of proofs.

In the history of philosophy three types of proofs have most prominently been utilized: rational proofs, empirical proofs, and pragmatic proofs. As pertains to the subject of apologetics, a rational-type of proof would entail the apologetic methodologies of the early Christian Fathers, Aquinas, and other Enlightenment Christians (or deists). In such instances the apologist wields the use of his reason to procure a valid argument that proves Christian theism to be true (or at the very least probable). Empirical-type proofs can be found primarily in the evidential approaches of today. This particular proof comes most easily to American audiences given our scientific achievements and where science is the reigning dogma of the modern age. Empirical-type proofs appeal to the senses to prove the truths of Christianity—things such as archaeological and historical evidences, the historical reliability of biblical manuscripts, and even design arguments. Finally, pragmatic-type proofs adhere to the thesis that “truth is what works.” Overlooking the problems that plague pragmatism as an epistemology, a pragmatic approach to apologetics would be an appeal to one’s change in lifestyle: “Christianity has solved many of the problems in my life and brought to me inner tranquility as I read and learn about the love of God.” Of the three types of proofs, this one seems rather intuitively weak given the inherent subjectivity it entails.

Notwithstanding the defects of this third type of proof, almost everyone in the Western world has a firm grasp on rational and empirical-type of proofs and how they can be wielded not just in apologetics but also in all other fields of study. The problem the presuppositionalist suffers, therefore, is having to introduce the notion of transcendental proof as it stands over against these other proofs which are, in fact, understood prima facie. Although it can be found as far back as Aristotle, transcendental proof was not popularized until Immanuel Kant’s transcendental idealism of the 18th Century. And given its relatively short lifespan, transcendental reasoning has not been widely embraced since then as empiricism for instance has. Transcendental and transcendental-type arguments resurfaced in the 20th Century, but they were treated more as frivolous attempts to defeat skepticism than anything to seriously consider. What, then, is transcendental proof?

In simple terms, transcendental reasoning/proof seeks to establish the necessary preconditions of intelligible experience. “What must be true in order for experience (or a particular experience) to be the case?” the transcendentalist asks. Take the fact that we can use the scientific method to send people to the moon. This is an obvious truth and a historical event that indeed happened. The transcendentalist asks the skeptical opponent what had to have been true in order for that to even be possible? Well, first nature must have been (and be) uniform and operate in a causal fashion such that we could even hypothesize, run tests, and so forth. If nature did not operate in a uniform way the entire venture of science would itself be an impossibility. Thus, we can prove the uniformity of nature transcendentally, from the impossibility of the contrary—if nature was not uniform we couldn’t even argue about anything at all, let alone send people to the moon. We see here the indirect nature of transcendental proof in that it assumes the opposite of what it’s trying to prove and shows the absurdity or impossibility of that outcome.

Another example is found in Descartes’ cogito argument. What is something no rational human being could doubt? Well, can a rational person doubt that he even exists? The obvious answer would be no. If you are even able to doubt anything at all you must first exist in order to do the doubting. Here we see a transcendental proof in that it assumes that one does not exist and shows that if that were the case then you couldn’t even doubt anything at all.

As pertains to presuppositional apologetics, the Transcendental Arguments for the Existence of God (TAG) argues that if one rejects the Christian worldview they are reduced to utter absurdity and an impossible reality. The presuppositionalist asks, “What needs to be the case in order to make sense out of our human experiences?” On this fundamental question he assumes for the sake of the argument any non-Christian worldview to show that on its own terms it reduces to absurdity, inadequate for the task of explaining intelligibility. He then asks his opponent to stand on his worldview to show that Christian theism has an explanation for everything in the universe. It is through this transcendental proof that Christianity is proved to be true by showing the impossibility of the contrary. That is the transcendental proof for the existence of God.



"... presuppositionalism embraces what is known as a transcendental proof for the existence of God, arguing over presuppositions of differing opponents’ worldviews and from the impossibility of the contrary—that Christianity alone makes sense out of the intelligibility of human experience and therefore any contrary anti-Christian philosophy of life is impossible."

Specifically, "... Christianity alone makes sense out of the intelligibility of human experience... "

How is this not a pragmatic argument? Let me translate into simple terms, "Christianity is the only worldview that works and explains..."


I understand Joshua Pillows is only new to presuppositional apologetics. He is no doubt a quick study as evidenced by his excellent TAG summary. I hope to see much more of his insightful work well into the future.

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